Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| allozyme genotype--environment relationships in natural populations of drosophila buzzatii. | allozyme frequency data from natural populations of drosophila buzzatii were analyzed for genotype--environment relationships. allele frequency and heterozygosity at six loci polymorphic throughout eastern australia and a number of environmental factors (both means and variabilities) were examined by a variety of multivariate techniques. significant genotype--environment associations were found for five of the six loci, and after correcting for geographic location significant associations remain ... | 1979 | 454353 |
| chromosome variability in brazilian populations of drosophila buzzatii (diptera, drosophilidae). | analysis of 28 strains of drosophila buzzatii from six different localities revealed that populations from southern brazil apparently differ from northeastern populations in chromosome structure. of the 16 polymorphic chromosome inversions detected in this species, only two (2j and 5c2) were present in southern populations. the northeastern populations were the first of this species found not to have the 2j inversion. this suggests that the populations of drosophila buzzatii may have lost chromo ... | 1992 | 1340927 |
| the evolutionary history of drosophila buzzatii. xxiii. high content of nonsatellite repetitive dna in d. buzzatii and in its sibling d. koepferae. | the frequency and types of repetitive nonsatellite dna of two sibling species of the repleta group of drosophila, d. buzzatii, and d. koepferae have been determined. for each species, the analysis is based on a sample of more than 100 clones (400 kb) obtained from genomic dna. a theoretical model has been developed to correct for the presence of a mixture of repetitive and unique dna in these clones. after correction, a high content of repetitive dna has been demonstrated for both species (d. bu ... | 1992 | 1473728 |
| the evolutionary history of drosophila buzzatii. xxv. random mating in nature. | using allozymes as the genetic probe, data are presented which show that wild drosophila buzzatii females and males engaged in copulation mate at random. hence, putative inbreeding due to local mating of genetically related flies emerging from the patchy distributed substrates, was not detected. we conclude that individuals raised from a niche disperse and mate at random with other members of the population, so only one round of drift due to the colonization of suitable and ephemeral breeding si ... | 1992 | 1563969 |
| the evolutionary history of drosophila buzzatii. xxiv. second chromosome inversions have different average effects on thorax length. | we demonstrate a genetic correlation between rearrangements of the second chromosome of d. buzzatii and thorax length, as a measure of body size. the results indicate that 2j and 2jz3 arrangements are correlated with large size, whereas 2st arrangement is correlated with small size. some inversions (2st and 2jz3) show dominant effects and others (2j/jz3) exhibit overdominance. these results show that at least 25 per cent of body size variation may be accounted for by the studied karyotypes. the ... | 1992 | 1612928 |
| genetic variance for body size in a natural population of drosophila buzzatii. | previous work has shown thorax length to be under directional selection in the drosophila buzzatii population of carboneras. in order to predict the genetic consequences of natural selection, genetic variation for this trait was investigated in two ways. first, narrow sense heritability was estimated in the laboratory f2 generation of a sample of wild flies by means of the offspring-parent regression. a relatively high value, 0.59, was obtained. because the phenotypic variance of wild flies was ... | 1991 | 1916242 |
| the evolutionary history of drosophila buzzatii. xxi. cumulative action of multiple sterility factors on spermatogenesis in hybrids of d. buzzatii and d. koepferae. | the genetic basis of sterility in male hybrids of drosophila buzzatii and d. koepferae has been investigated by assessment of the effects on spermatogenesis of substituting separate chromosome segments of the recipient species with the homologous material from the donor species, either in heterozygous (autosomes) or hemizygous (x chromosome) condition, after successive backcrossing of hybrid females to either parental species. introgressed segments were identified by the characteristic asynapsis ... | 1991 | 1917552 |
| the evolutionary history of d. buzzatii. xxii. chromosomal and genic sterility in male hybrids of drosophila buzzatii and drosophila koepferae. | the genetic basis of sterility in f1 male hybrids of drosophila buzzatii and d. koepferae has been investigated in two steps. (1) by successive backcrossing of hybrid females to either parental species. (2) by assessment of the effects on male fertility of selected segments of polytene chromosomes from the donor species on a background entirely derived from the recipient species. the length of introgressed segments producing sterility was progressively reduced through repeated backcrosses. this ... | 1991 | 2061093 |
| breeding structure of natural populations of drosophila buzzatii: effects of the distribution of larval substrates. | the population structure of several australian populations of the cactophilic drosophila buzzatti was investigated, with seasonal samples from two populations analyzed for six polymorphic allozymes. significant inbreeding throughout the year was detected in both populations, and significant but relatively slight differences in allele frequencies between collections were found in one population. little significant 2-locus linkage disequilibrium was detected and the variances of linkage disequilib ... | 1990 | 2358367 |
| ecological aspects of the heritability of body size in drosophila buzzatii. | the heritability of thorax length in the cactophilic drosophila buzzatii was determined for flies from each of 10 rotting cactus cladodes. for each rot, emerging flies were used as parents of progeny reared in the laboratory. the methods used were full sib analysis with the parents mated assortatively and also offspring-parent regression. from this, heritabilities were measured for the laboratory environment and for the natural environment of the rotting cladode. for the laboratory environment, ... | 1989 | 2612896 |
| the genetics of abnormal abdomen, incomplete abdomen, and bobbed in drosophila buzzatii. | five stocks of drosophila buzzatii with superficially similar abdominal disruptions including partial tergite and sternite loss were isolated by inbreeding. three of the stocks have indistinguishable phenotypes, the inheritance of which is maternally influenced. this phenotype and its mode of inheritance bear similarities with those of abnormal abdomen in d. melanogaster. the phenotype in the fourth stock is slightly different and is due to a single autosomal recessive gene, which we denote inco ... | 2008 | 2620817 |
| frequency and temperature dependent selection at the alcohol dehydrogenase-1 locus of drosophila buzzatii. | genotype frequencies at the alcohol dehydrogenase-1 (adh-1) locus of d. buzzatii were analysed for deviations from hardy-weinberg equilibria in the progeny of laboratory populations established at five initial adh-1b allele frequencies and kept at either 18 degrees c, 25 degrees c or 30 degrees c. at 25 degrees c, no observed genotype frequencies were significantly different from hardy-weinberg expectations. observed frequencies of heterozygotes were generally less than expected for populations ... | 1986 | 2943702 |
| polymorphic inversion and esterase loci complex on chromosome 2 of drosophila buzzatii. ii. spatial variation. | the potential influence of linked inversions on allele frequency variation at the est-1 and est-2 loci among australian populations of d. buzzatii was determined by statistical analyses allele and inversion gametic frequencies. most of the significant spatial and climatic associations found for all est-1 allele frequencies, and for one allele only of est-2 (est-2c+), were accounted for by their linkage disequilibria with the inversions, which covaried with environmental variables. consistent wit ... | 1988 | 3270311 |
| differential response to environmental alcohol among second-chromosome arrangements in experimental populations of drosophila buzzatii. | drosophila buzzatii feeds and breeds on the decaying cladodes and fruits of several species of opuntia (prickly pear) which contain significant levels of ethanol and isopropanol. the potential influence of these two alcohols on the inversion polymorphism of the second and fourth chromosomes was investigated in ten experimental populations with different amounts of alcohol (either ethanol or isopropanol) added to the culture medium. all populations were started with the offspring of 29 wild femal ... | 1987 | 3505227 |
| allozyme genotypes of drosophila buzzatii: feeding and oviposition preferences for microbial species, and habitat selection. | mature, mated female d. buzzatii were given a choice of nine microbial communities actively growing on cactus homogenate in laboratory population cages, and tests were made to determine if flies of different genotypes (for seven allozyme loci) chose different microorganism species for either feeding or oviposition. variation in feeding preferences was determined from assays of electrophoretic genotypes and the ingested microorganism species of individual flies. oviposition preference variation w ... | 1986 | 3778358 |
| temporal and microgeographic variation in allozyme frequencies in a natural population of drosophila buzzatii. | temporal variation in allozyme frequencies at six loci was studied by making monthly collections over 4 yr in one population of the cactophilic species drosophila buzzatii. ten sites were defined within the study locality, and for all temporal samples, separate collections were made at each of these sites. population structure over microgeographic space and changes in population structure over time were analyzed using f-statistic estimators, and multivariate analyses of allele and genotype frequ ... | 1986 | 3957005 |
| the evolutionary history of drosophila buzzatii. ix. high frequencies of new chromosome rearrangements induced by introgressive hybridization. | introgression of a chromosome segment from drosophila serido into the genome of its sibling d. buzzatii brought about the release of mutator potential in the hybrids. mutator activity was determined by examining the frequency of new chromosomal rearrangements, that appeared only in the progeny of hybrid individuals. mutation frequency was 30 times greater in the progeny of hybrid males than in that of hybrid females. there was a remarkable influence of the d. buzzatii genetic background on the f ... | 1985 | 3987443 |
| high transposition rates of osvaldo, a new drosophila buzzatii retrotransposon. | transposition of a new drosophila retrotransposon was investigated. total genomic southern analysis and polytene in situ hybridizations in d. buzzatii strains and other related species using a 6 kb d. buzzatii clone (cdb314) showed a dispersed, repetitive dna pattern, suggesting that this clone contains a transposable element (te). we have sequenced the cdb314 clone and demonstrated that it contains all the conserved protein sequences and motifs typical of retrovirus-related sequences. although ... | 1994 | 7545973 |
| heat-shock tolerance and inbreeding in drosophila buzzatii. | the effect of inbreeding on survival after a short-term heat shock was tested for two age groups of the cactophilic fruit fly, drosophila buzzatii, reared under nonstress conditions. four inbreeding levels (f = 0, f = 0.25, f = 0.375, f = 0.5) were generated by outcrossing or full-sib mating. all flies were conditioned at 36.5 degrees c for 75 min prior to exposure to stress, to activate the synthesis of heat-shock proteins. these proteins are known to protect cells against stress damage. the yo ... | 1995 | 7706108 |
| the evolutionary history of drosophila buzzatii. xxxii. linkage disequilibrium between allozymes and chromosome inversions in two colonizing populations. | chromosome polymorphism in drosophila buzzatii is under selection but the genes responsible for the effect of the inversions of fitness are unknown. on the other hand, there is evidence for selection on several allozyme loci but the presence of paracentric inversions on the second chromosome, where most of the polymorphic loci are located, complicates the interpretation. studies of the associations between allozymes and inversions are thus necessary to help understand the effect of selection at ... | 1995 | 7706110 |
| genetic structure is determined by stochastic factors in a natural population of drosophila buzzatii in argentina. | d. buzzatii is a cactophilic species associated with several cactaceae in argentina. this particular ecological niche implies that this species is faced with a non-uniform environment constituted by discrete and ephemeral breeding sites, which are colonized by a finite number of inseminated females. the genetic consequences of this population structure upon the second chromosome polymorphism were investigated by means of f-statistics in a natural endemic population of argentina. the present stud ... | 1994 | 7958936 |
| sequential gel electrophoretic analysis of esterase-2 in two populations of drosophila buzzatii. | sequential electrophoresis, using three different buffer systems on cellulose acetate gels, was used to characterize the allelic variation for esterase-2 in two populations of d. buzzatii in australia that are separated by 550 km. twenty-five alleles were detected, of which nine were unique to one population, eight unique to the other, and only eight were common to both populations. allele frequencies within each population were significantly different between the two major chromosome sequences ... | 1994 | 7958940 |
| fatty acid elongation in the biosynthesis of (z)-10-heptadecen-2-one and 2-tridecanone in ejaculatory bulb microsomes of drosophila buzzatii. | a fatty acid chain elongation process is involved in incorporation of saturated and unsaturated fatty acyl-coa esters into 2-tridecanone and (z)-10-heptadecen-2-one by drosophila buzzatii. the microsomal fraction from mature male ejaculatory bulbs is chain-length specific and requires malonyl-coa (or acetyl-coa, if acetyl-coa carboxylase were present) for the chain elongation step to 2-ketones. decarboxylation of the proposed intermediate beta-ketoacid results in 2-ketone biosynthesis. incubatio ... | 1994 | 7981731 |
| response to environmental change: genetic variation and fitness in drosophila buzzatii following temperature stress. | drosophila buzzatii typically may encounter high temperatures in nature, and this species is genetically variable for resistance to stress, both within and among populations. fitness of survivors to stress, however, was reduced, and observed as a reduction in male fertility and female fecundity. with time following exposure to severe stress, reproductive capacity improved, but lifetime offspring production still was reduced significantly. this effect would greatly reduce a population's recovery ... | 1994 | 8032136 |
| the evolutionary history of drosophila buzzatii. xxvii. thorax length is positively correlated with longevity in a natural population from argentina. | the correlation between body size and longevity was tested in an argentinian natural population of drosophila buzzatii. mean thorax length of flies newly emerging from rotting cladodes of opuntia vulgaris was significantly smaller than that of two samples of flies caught at baits. the present results which might be interpreted as directional selection for longevity favoring larger flies are in agreement with previous results achieved in a spanish natural population of d. buzzatii. flies emerging ... | 1993 | 8163157 |
| genotype-specific habitat selection for oviposition sites in the cactophilic species drosophila buzzatii. | isofemale lines of the cactophilic species, drosophila buzzatii, exhibit genetic variation for their oviposition response to cactus yeast species in the laboratory. in general, interactions between yeast species preclude the use of pairwise preferences as predictors of preferences in three-way choice experiments. two isofemale lines with relatively high laboratory preference for ovipositing on the yeast pichia cactophila (as opposed to cryptococcus cereanus) and two isofemale lines with relative ... | 1994 | 8200815 |
| genetics and linkage mapping of drosophila buzzatii. | of 51 visible mutants isolated from natural or laboratory populations of drosophila buzzatii, or x-ray induced, 42 have been assigned to chromosomes, and linkage maps have been constructed. about half of the autosomal mutants map to chromosome 2, with only two on chromosome 3 and none on chromosome 4. for the whole repleta group, chromosome 2 also exhibits much greater inversion variability than other chromosomes, which suggests variation among chromosomes in apparent mutability. the chromosomes ... | 2010 | 8228173 |
| evolutionary cytogenetics of the drosophila buzzatii species complex. | the salivary gland chromosomes of 10 species in the drosophila mulleri subgroup (repleta group) have been re-analysed. these include the eight members of the south american buzzatti and martensis clusters, previously ascribed to the mulleri complex, and the two caribbean species d. stalkeri and d. richardsoni, previously comprising the stalkeri complex. the chief results can be summarized as follows. inversion 3a is not present in the martensis cluster. hence, there is no cytological link betwee ... | 1993 | 8335477 |
| lack of mitochondrial dna variation in australian drosophila buzzatii. | 1993 | 8487641 | |
| f statistics in drosophila buzzatii: selection, population size and inbreeding. | drosophila buzzatii is confined to reproducing in a well defined patchy environment consisting of rotting cactus cladodes which are ephemeral, permitting at most three generations. flies emerging from such rots were used to estimate the additive genetic variance within rots and the genetic variance between rots for body size and also were electrophoresed to determine their genotypes at six polymorphic loci. f statistics were estimated from body size and allozyme data. the fst derived from body s ... | 1993 | 8514144 |
| an adaptive chromosomal polymorphism affecting size-related traits, and longevity selection in a natural population of drosophila buzzatii. | size-related phenotypic variation among second-chromosome karyotypes in drosophila buzzatii was examined in an argentinian natural population. for all measured traits (thorax and wing length; wing, head and face width), this inversion polymorphism exhibited a significant and (additive) linear contribution to the phenotypic variance in newly emerged wild flies. the results suggest that only overall body size, and not body shape, is affected, as no karyotypic variation was found for any trait when ... | 1995 | 8522167 |
| heritability and selection on body size in a natural population of drosophila buzzatii. | an attempt was made to assess whether the phenotypic differences in body size (as measured by wing length) between wild-caught mating and single drosophila buzzatii males could be attributed to genetic differences between the samples. mating males were found to be larger and less variable than a random sample of the population. the progeny of the mating males (produced by crossing to a random female from a stock derived from the same population) were on average larger than those of the single ma ... | 1995 | 8536966 |
| phylogenetic utility of the mitochondrial cytochrome oxidase gene: molecular evolution of the drosophila buzzatii species complex. | phylogenetic relationships among eight species of the drosophila buzzatii species complex (d. mulleri subgroup; d. repleta species group) and d. hamatofila were determined by sequencing the mitochondrial cytochrome oxidase subunit i, ii, and iii genes. the species examined included members of the martensis cluster (d. martensis, d. starmeri, d. venezolana), the buzzatii cluster (d. buzzatii, d. serido, d. borborema), and the stalkeri cluster (d. stalkeri, d. richardsoni). the molecular phylogeny ... | 1995 | 8587120 |
| the evolutionary history of drosophila buzzatii. xxx. mitochondrial dna polymorphism in original and colonizing populations. | both original and colonizer populations of drosophila buzzatii have been analyzed for mtdna restriction polymorphisms. most of the mtdna nucleotide variation in original populations of nw argentina can be explained by intrapopulation diversity and only a small fraction can be accounted for by between-population diversity. similar results are obtained using either the estimated number of nucleotide substitutions per site or considering each restriction site as a locus. colonizer populations of th ... | 1996 | 8587497 |
| esterase patterns of species in the drosophila buzzatii cluster. | a comparative analysis was made of the esterase isoenzyme patterns of eight iso-female lines, four of drosophila serido (b31 d1, a55, b59, q1, b50q3), two of d. koepferae (b20d2 and b25d7), one of d. seriema (a95) and one of d. buzzatii (buz). in all, 43 bands in the spectrum of esterase isoenzymes were detected by electrophoresis in polyacrylamide gels. they showed variations in specific reactions with alpha and beta-naphthyl acetate, number of patterns yielded in their intra-isofemale line com ... | 1995 | 8681607 |
| a three-locus system of interspecific incompatibility underlies male inviability in hybrids between drosophila buzzatii and d. koepferae. | in hybrids between the sibling species d. buzzatii and d. koepferae, both sexes are more or less equally viable in the f1. however, backcross males to d. buzzatii are frequently inviable, apparently because of interspecific genetic incompatibilities that are cryptic in the f1. we have performed a genetic dissection of the effects of the x chromosome from d. koepferae. we found only two cytological regions, termed hmi-1 and hmi-2, altogether representing 9% of the whole chromosome, which when int ... | 1996 | 8765678 |
| genetic architecture of autosome-mediated hybrid male sterility in drosophila. | several estimators have been developed for assessing the number of sterility factors in a chromosome based on the sizes of fertile and sterile introgressed fragments. assuming that two factors are required for producing sterility, simulations show that one of these, twice the inverse of the relative size of the largest fertile fragment, provides good average approximations when as few as five fertile fragments are analyzed. the estimators have been used for deducing the number of factors from pr ... | 1996 | 8846896 |
| acclimation and selection for increased resistance to thermal stress in drosophila buzzatii. | direct selection for increased resistance to a heat shock (41.9 degrees for 90 min) was carried out using two replicate lines of drosophila buzzatii that were derived from a large base population. selected individuals were first acclimated to high temperature before selection, while control individuals were acclimated but not selected, and selection was performed every second generation. resistance to heat shock with acclimation increased in selected lines. without acclimation, a correlated smal ... | 1996 | 8852846 |
| the evolutionary history of drosophila buzzatii. xxxiii. are opuntia hosts a selective factor for the inversion polymorphism? | previous work has shown fitness differences among chromosomal arrangements by means of selection component analysis in two drosophila buzzatii natural populations, one of which is native to argentina and the other a colonized population from carboneras, spain. founder effects or niche shifts were proposed to explain the differences observed in the pattern of pleiotropic effects of inversions on fitness components. in this paper, we address the possible role of niche shifts by determining whether ... | 1996 | 8939019 |
| effects of inbreeding in three life stages of drosophila buzzatii after embryos were exposed to a high temperature stress. | the interaction between inbreeding and high-temperature stress was examined in the cactophilic fruit fly, drosophila buzzatii. embryos of four inbreeding levels (f = 0, f = 0.25, f = 0.375, f = 0.5) were either maintained at 25 degrees c throughout egg-to-adult development or were exposed to 41.5 degrees c for 110 min at an age of 20 h. hatching, larva-to-pupa survival, pupa-to-adult survival, and egg-to-adult survival were estimated. heat shock reduced hatching rates, but survival to adulthood ... | 1997 | 9134706 |
| reproductive compatibility and chromosome pairing in the drosophila buzzatii complex. | fertility (percentage of fertile crosses) and the degree of synapsis in salivary gland chromosomes in isofemale lines of drosophila buzzatii, d. serido, d. koepferae and d. seriema were analysed. d. buzzatii was completely sterile in intercrosses with strains from the other species except for d. koepferae. the other species intercrossed to a greater or lesser degree, but also differed between crossing directions. homologous pairing in salivary gland preparations of strains and hybrids conformed ... | 1997 | 9297813 |
| estimating heritability in a threshold trait: heat-shock tolerance in drosophila buzzatii. | stress tolerance is often measured as a threshold trait, the proportion of a group that survives a defined stress regime. requirements of large offspring numbers coupled with fitness variation in the surviving cohort limit the use of some standard genetic analyses for estimating heritability. therefore, we present an isofemale line analysis, which is a modified full-sib design, to estimate heritability of tolerance to heat shock in pretreated drosophila buzzatii adults. highly significant levels ... | 1997 | 9316252 |
| high-temperature stress and the evolution of thermal resistance in drosophila. | the evolution of thermal resistance and acclimation is reviewed at the population level using populations and isofemale lines of drosophila buzzatii and d. melanogaster originating from different climatic regions. in general, ample genetic variation for thermal resistance was found within and among populations. a rough correlation between the climate of origin and thermal resistance was apparent. acclimation at a non-lethal temperature led to a significant increase in survival after heat shock, ... | 1997 | 9342849 |
| correlations among size-related traits affected by chromosome inversions in drosophila buzzatii: the comparison within and across environments. | genetic variation in correlations among size-related traits of head, thorax, and wings was examined in drosophila buzzatii, by comparing the pattern of the phenotypic correlation matrix (rp) between inversion karyotypes of the second chromosome. no similarity in rp was observed between some karyotypes in a natural population. the pattern of rp in wild-reared heterokaryotypes, but not in homokaryotypes, was similar to the whole population represented by laboratory-reared flies. while phenotypic c ... | 1997 | 9350137 |
| the effect of polymorphic inversions on body size in two natural populations of drosophila buzzatii from argentina. | previous works in a colonized and an original population of drosophila buzzatii have shown a consistent relationship between the inversion polymorphism and thorax length, a measure of body size. however, the populations studied in those reports share a close genealogical relationship as suggested by several lines of evidence. in the present paper, we revisit this issue by analysing the correlation between second chromosome arrangements and thorax length in two argentinian natural populations (te ... | 1997 | 9350138 |
| correlations among size-related traits are affected by chromosome inversions in an adaptive polymorphism in drosophila buzzatii. | genetic variation in correlations among size-related traits of head, thorax and wings was examined in drosophila buzzatii, by comparing the correlation pattern of the phenotypic correlation matrix (cp-rp) between inversion karyotypes of the second chromosome. cp-rp differed between some karyotypes in a natural population. cp-rp in homokaryotypic classes of wild-reared flies, but not in heterokaryotypes, differed from the whole population represented by laboratory-reared flies. similarity in cp-r ... | 1997 | 9418266 |
| genetic and phenotypic correlations among size-related traits, and heritability variation between body parts in drosophila buzzatii. | recent studies have shown that body size is a heritable trait phenotypically correlated with several fitness components in wild populations of the cactophilic fly drosophila buzzatii. to obtain further information on size-related variation, heritabilities as well as genetic and phenotypic correlations among size-related traits of several body parts (head, thorax and wings) were estimated. the study was carried out on an argentinean natural population in which size-related selection was previousl ... | 1997 | 9465404 |
| sexual selection related to developmental stability in drosophila buzzatii. | relationships among developmental stability, sexual selection, and body size were examined in the cactophilic fly drosophila buzzatii. developmental stability, as measured in terms of fluctuating asymmetry (fa) of wing length, was positively associated to male's copulatory success in a mass-mating experiment with wild-reared flies. previous studies showed that body size is positively correlated with mating success and other fitness components in this species, but no phenotypic correlation betwee ... | 1998 | 9652230 |
| stable drosophila buzzatii-drosophila koepferae hybrids. | previous experiments discovered high rates of chromosomal rearrangements in the progeny of males containing a telomeric segment of drosophila koepferae in a d. buzzatii genetic background (segmental males). we have performed similar experiments, designed to test whether this chromosomal instability could be explained by a phenomenon similar to p-m hybrid dysgenesis or, alternatively, by a generalized telomeric effect. however, the results obtained have not allowed us to fully characterize this p ... | 2006 | 9703688 |
| esterase patterns and phylogenetic relationships of species and strains included in the drosophila buzzatii cluster. | ten strains of two species in the drosophila buzzatii cluster (d. serido and d. seriema) were examined as to esterase patterns using polyacrylamide gel electrophoresis. the migration rate of esterases, and their substrate specificity to alpha and beta naphthyl acetates, were analysed. other esterase features such as inhibition behaviour, presence in males and females and location in the head, thorax or abdomen of flies, were also examined. the present data, together with results obtained by othe ... | 1998 | 10384711 |
| the retrotransposon osvaldo from drosophila buzzatii displays all structural features of a functional retrovirus. | the osvaldo retrotransposon has shown a high transposition rate in some strains of drosophila buzzatii and in hybrids between d. buzzatii and its sibling d. koepferae. in order to understand the molecular basis of this phenomenon, we developed a procedure to clone a recently transposed copy with the aim of characterizing an active, full- length osvaldo element. the complete nucleotide sequence of osvaldo, obtained from a recent insertion site, was determined. osvaldo is 9,045 bp long and is comp ... | 1999 | 10406108 |
| interspecific hybridization increases transposition rates of osvaldo. | several authors have postulated that genetic divergence between populations could result in genomic incompatibilities that would cause an increase in transposition in their hybrids, producing secondary effects such as sterility and therefore starting a speciation process. it has been demonstrated that transposition largely depends on intraspecific hybridization for p, hobo, and i elements in drosophila melanogaster and for several elements, including long terminal repeat (ltr) and non-ltr retrot ... | 1999 | 10406110 |
| a genetic analysis of the relationship between life-history variation and heat-shock tolerance in drosophila buzzatii. | although exposure to environmental stress is common in most populations, and the physiological effects of stress on individuals are well studied, the evolutionary importance of stress to populations is not well understood. to address multitrait responses to environmental change and potential constraints on character evolution, we analysed, in 100 isofemale lines of drosophila buzzatii, the genetic relationships between resistance to a short heat shock and several life-history traits: survival in ... | 1999 | 10447702 |
| environmental effects and the genetics of oviposition site preference for natural yeast substrates in drosophila buzzatii | habitat selection expressed as oviposition site preferences (osp), is one component of the complex of behaviours of females seeking a place to oviposit. drosophila buzzatii females lay their eggs in cactus necroses (rots), where the alternative oviposition sites are patches of adjacent or even partially mixed growing yeast species. the osp exhibited by individual females is not absolute, but subject to environmental effects and the physiology of the fly, and may vary depending on the particular ... | 1999 | 10479998 |
| temporal and spatial variation of inversion polymorphism in two natural populations of drosophila buzzatii. | the inversion polymorphism of the cactophilic fly drosophila buzzatii was studied in two natural populations. we assessed the temporal changes and microspatial population structure. we observed a significant increase in the frequency of arrangement 2j at the expense of 2st in both populations. these gene arrangements appear to affect the life-history of flies differently. environmental heterogeneity explains the karyotype coexistence in nature. the analysis of population structure showed that di ... | 1999 | 10680294 |
| expression of the heat-shock protein hsp70 in drosophila buzzatii lines selected for thermal resistance. | the level of hsp70 expression induced by a non-lethal high temperature was examined in lines selected for increased thermal resistance and in corresponding control lines of drosophila buzzatii, in order to test if selection for high temperature resistance leads to an increased level of hsp70 expression. the lines used were selected for up to 64 generations either as adults or through all larval stages. in adult selection lines, hard selection was implemented every second generation after mild he ... | 1999 | 10680297 |
| reconstructing the diversification of alpha-esterases: comparing the gene clusters of drosophila buzzatii and d. melanogaster. | a cluster composed of 10 active alpha-esterase genes and a pseudogene is distributed over 60 kb in the drosophila melanogaster genome. this paper describes the corresponding cluster in drosophila buzzatii, whose lineage diverged from that of d. melanogaster when the subgenera drosophila and sophophora diverged about 50 mya. with three exceptions we find that the composition of the cluster is conserved in the two lineages. the location of alpha e1 in d. melanogaster differs from that of its neare ... | 2000 | 10948271 |
| duplication, dicistronic transcription, and subsequent evolution of the alcohol dehydrogenase and alcohol dehydrogenase-related genes in drosophila. | it has recently been discovered that the alcohol dehydrogenase and alcohol dehydrogenase-related genes of drosophila melanogaster and closely related species constitute a single transcription unit and that the alcohol dehydrogenase-related gene is exclusively expressed from a dicistronic mrna. here, we show that in drosophila lebanonensis, subgenus scaptodrosophila, adhr: is also transcribed as a dicistronic transcript with adh using degenerate primers designed on the sequence of the known adhr ... | 2000 | 10958851 |
| the role of the use of different host plants in the maintenance of the inversion polymorphism in the cactophilic drosophila buzzatii. | inversion polymorphisms often have been associated with fitness variation. cactophilic drosophila buzzatii has been used widely for the study of the maintenance of chromosomal variation. the purpose of this paper is to address the relative importance of variable selection regimes associated with the use of three different host cacti and antagonistic pleiotropy in the maintenance of chromosomal variation. using homokaryotypic stocks derived from several lines homozygous for four second-chromosome ... | 2000 | 11005296 |
| toward a physical map of drosophila buzzatii. use of randomly amplified polymorphic dna polymorphisms and sequence-tagged site landmarks. | we present a physical map based on rapd polymorphic fragments and sequence-tagged sites (stss) for the repleta group species drosophila buzzatii. one hundred forty-four rapd markers have been used as probes for in situ hybridization to the polytene chromosomes, and positive results allowing the precise localization of 108 rapds were obtained. of these, 73 behave as effectively unique markers for physical map construction, and in 9 additional cases the probes gave two hybridization signals, each ... | 2000 | 11102375 |
| behavioral differentiation in oviposition activity in drosophila buzzatii from highland and lowland populations in argentina: plasticity or thermal adaptation? | highland populations of several drosophila species in argentina were active early in the afternoon in the field as opposed to populations from a much warmer lowland site, where flies were mainly active in the early evening prior to sunset. for one of these species, drosophila buzzatii, we tested for a genetic component of activity differences by carrying out crosses within and between populations and measuring oviposition activity of the progeny in the laboratory. we found that activity in the h ... | 2001 | 11392392 |
| molecular characterization of two natural hotspots in the drosophila buzzatii genome induced by transposon insertions. | transposable elements (tes) have been implicated in the generation of genetic rearrangements, but their potential to mediate changes in the organization and architecture of host genomes could be even greater than previously thought. here, we describe the naturally occurring structural and nucleotide variation around two te insertions in the genome of drosophila buzzatii. the studied regions correspond to the breakpoints of a widespread chromosomal inversion generated by ectopic recombination bet ... | 0 | 11483576 |
| chromosomal distribution of the transposable elements osvaldo and blanco in original and colonizer populations of drosophila buzzatii. | chromosomal distribution of transposable elements (tes) osvaldo and blanco in d. buzzatii was studied in three original natural populations from argentina (berna, puerto tirol and la nostalgia) and a colonizer population from the iberian peninsula (carboneras). the spanish population showed significant differences for osvaldo and blanco copy numbers when we compared the x chromosome and the autosomes; but it is mainly the accumulation of copies in chromosome 2, where most sites with high inserti ... | 2001 | 11486506 |
| gametic associations between inversion and allozyme polymorphisms in drosophila buzzatii. | gametic disequilibria between second chromosome polymorphic arrangements and seven linked allozyme loci were estimated in seven populations of drosophila buzzatii from argentina. significant and consistent associations across populations were detected for est-1, est-2, aldox, and xdh: phenograms based on nei's genetic distance showed that chromosomes carrying the 2st arrangement were more similar to each other, irrespective of the population from which they were extracted, than to chromosomes ca ... | 2001 | 11773244 |
| fluctuating asymmetry is nongenetically related to mating success in drosophila buzzatii. | to date, there is still no consensus on the real significance of fluctuating asymmetry (fa) in evolutionary biology. some studies have established links between fa and darwinian fitness, and in a number of cases intermediate heritabilities for fa have been reported. however, many claims have been raised against the generality of these findings. i therefore tested if fa of a sexually selected trait (wing length) is indeed related to male mating success in drosophila buzzatii from field and labora ... | 2001 | 11794784 |
| oviposition acceptance and fecundity schedule in the cactophilic sibling species drosophila buzzatii and d. koepferae on their natural hosts. | we tested for the occurrence of oviposition acceptance for different media prepared with cactus tissues of three alternative cactus hosts: opuntia sulphurea, o. quimilo and trichocereus terschekii for 4 consecutive days in lines of two drosophila buzzatii populations and one population of d. koepferae. our results showed that the former laid significantly more eggs on both opuntia cacti than on t. terschekii, whereas d. koepferae preferred t. terschekii. in addition, fecundity schedules differed ... | 2001 | 11831675 |
| genetic variation in original and colonizing drosophila buzzatii populations analysed by microsatellite loci isolated with a new pcr screening method. | a new polymerase chain reaction-based screening method for microsatellites is presented. using this method, we isolated 12 microsatellite loci from drosophila buzzatii, two of which were x-linked. we applied the other 10 microsatellite loci to the analysis of genetic variation in five natural populations of d. buzzatii. two populations were from the species' original distribution in argentina, whereas the other three were from europe (two) and australia that were colonized 200 and 65 years ago, ... | 2002 | 11856420 |
| developmental time, body size and wing loading in drosophila buzzatii from lowland and highland populations in argentina. | genotype-by-temperature interaction is a necessary condition for adaptive evolution of fitness traits as a response to temperature. several fitness-related traits (developmental time, pre-adult survival, thorax and wing lengths, and wing loading) were measured in laboratory-reared d. buzzatii from four populations sampled at different altitudes in north-western argentina: a lowland population (407 m a.s.l.), two populations from intermediate altitude (780 to 950 m a.s.l.), and a highland populat ... | 2001 | 12035612 |
| the evolutionary history of drosophila buzzatii. xxxiv. the distribution of the retrotransposon osvaldo in original and colonizing populations. | the frequency distribution of the retrotransposon osvaldo in the haploid genome of drosophila buzzatii has been studied in five natural populations from the iberian peninsula and six natural populations from argentina. in iberian populations, osvaldo insertion sites do not follow a poisson distribution, most probably due to eight euchromatic sites with high occupancy, found in all populations. the estimated alpha and beta parameters, which measure the relative importance of drift and negative se ... | 1998 | 12572617 |
| direct and correlated responses to artificial selection on developmental time and wing length in drosophila buzzatii. | developmental time and body size are two positively correlated traits closely related to fitness in many organisms including drosophila. previous work suggested that these two traits are involved in a trade-off that may result from a negative genetic correlation between their effects on pre-adult and adult fitness. here, we examine the evolution of developmental time and body size (indexed by wing length) under artificial selection applied to one or both traits in replicated d. buzzatii populati ... | 2002 | 12583594 |
| transpecific polymorphisms in an inversion linked esterase locus in drosophila buzzatii. | nucleotide variation was studied in a 1.1 kb section of the coding region of an esterase gene (est-a) that maps in the center of the segments rearranged by polymorphic inversions in the cactophilic drosophila buzzatii. we examine 30 homozygous second-chromosome lines differing in gene arrangement and three d. koepferae isofemale lines as outgroups. our data show that est-a is a highly polymorphic gene at both synonymous and replacement sites. significant departures from homogeneity in the distri ... | 2003 | 12644562 |
| evaluation of the courtship and of the hybrid male sterility among drosophila buzzatii cluster species (diptera, drosophilidae). | in the drosophila repleta group the establishment of subgroups and complexes made on the basis of morphological and cytological evidences is supported by tests of reproductive isolation. among species in the repleta group, the buzzatii cluster, due to its polymorphism and polytipism, is an excellent material for ecological and speciation studies. some interspecific crosses involving drosophila seriema, drosophila sp. b, d. koepferae and d. buzzatii strains were completely sterile while others in ... | 2002 | 12659009 |
| the foldback-like transposon galileo is involved in the generation of two different natural chromosomal inversions of drosophila buzzatii. | chromosomal inversions are the most common type of genome rearrangement in the genus drosophila. although the potential of transposable elements (tes) for generating inversions has been repeatedly demonstrated in the laboratory, little is known on their role in the generation of natural inversions, which are those effectively contributing to the adaptation and/or evolution of species. we have cloned and sequenced the two breakpoints of the polymorphic inversion 2q7 of d. buzzatii. the sequence a ... | 2003 | 12679549 |
| the evolutionary history of drosophila buzzatii. xxxv. inversion polymorphism and nucleotide variability in different regions of the second chromosome. | inversions are portions of a chromosome where the gene order is reversed relative to a standard reference orientation. because of reduced levels of recombination in heterokaryotypes, inversions have a potentially important effect on patterns of nucleotide variability in those genomic regions close to, or included in, the inverted fragments. here we report sequence variation at three anonymous regions (stss) located at different positions in relation to second-chromosome inversion breakpoints in ... | 2003 | 12716995 |
| chromosomal inversions effect body size and shape in different breeding resources in drosophila buzzatii. | the cactophilic drosophila buzzatii provides an excellent model for the study of reaction norms across discrete environments because it breeds on rotting tissues (rots) of very different cactus species. here we test the possible effects of second chromosome inversions on body size and shape (wing loading) across suitable natural breeding substrates. using homokaryotypic stocks derived from several lines homozygous for four naturally occurring chromosomal inversions, we show that arrangements sig ... | 2003 | 12815453 |
| comparative molecular population genetics of the xdh locus in the cactophilic sibling species drosophila buzzatii and d. koepferae. | the xdh (rosy) gene is one of the best studied in the drosophila genus from an evolutionary viewpoint. here we analyze nucleotide variation in a 1875-bp fragment of the second exon of xdh in argentinian populations of the cactophilic d. buzzatii and its sibling d. koepferae. the major electrophoretic alleles of d. buzzatii not only lack diagnostic amino acids in the region studied but also differ on average from each other by four to 13 amino acid changes. our data also suggest that d. buzzatii ... | 2004 | 14595098 |
| heat and cold-induced male sterility in drosophila buzzatii: genetic variation among populations for the duration of sterility. | here we studied three phenotypic traits in drosophila buzzatii that are strongly effected by temperature, and are expected to be closely associated with fitness in nature. the traits measured were thermal threshold of male sterility, time for males to gain fertility when reared at a sterility-inducing temperature and transferred to 25 degrees c on eclosion and survival after development. the last two traits were measured under four temperature regimes, constant 12 degrees c, 25 degrees c, 31 deg ... | 2004 | 14679393 |
| remating and sperm displacement in a natural population of drosophila buzzatii inferred from mother-offspring analysis of microsatellite loci. | prospects for estimation of parameters of models of sperm competition from field data have improved recently with the development of methods that employ multilocus genotype data from brood-structured samples. sperm competition in drosophila buzzatii is of special interest because it is possible to directly observe the breeding behaviour of this species in its natural habitat of rotting cactus. previous laboratory experiments showed that this species exhibits an unusual pattern of frequent remati ... | 2004 | 15009271 |
| on the pbum189 satellite dna variability among south american populations of drosophila buzzatii. | the pbum189 satellite dna was analysed in drosophila buzzatii populations that cover most of the species distribution in south america. this satdna consists of a + t-rich monomers of 189 bp and previous studies showed a fast rate of evolutionary change of this component of d. buzzatii genome. a total of 63 pbum189 repetition units from 14 d. buzzatii populations (9 from brazil and 5 from argentina) were studied. the average nucleotide variability among the 63 repeats is 4.2 %. at least one repea ... | 2003 | 15061796 |
| silencing of a gene adjacent to the breakpoint of a widespread drosophila inversion by a transposon-induced antisense rna. | adaptive changes in nature occur by a variety of mechanisms, and drosophila chromosomal inversions was one of the first studied examples. however, the precise genetic causes of the adaptive value of inversions remain uncertain. here we investigate the impact of the widespread inversion 2j of drosophila buzzatii on the expression of the cg13617 gene, whose coding region is located only 12 bp away from the inversion proximal breakpoint. this gene is transcribed into a 2.3-kb mrna present in all d. ... | 2004 | 15184654 |
| molecular characterization and chromosomal distribution of galileo, kepler and newton, three foldback transposable elements of the drosophila buzzatii species complex. | galileo is a foldback transposable element that has been implicated in the generation of two polymorphic chromosomal inversions in drosophila buzzatii. analysis of the inversion breakpoints led to the discovery of two additional elements, called kepler and newton, sharing sequence and structural similarities with galileo. here, we describe in detail the molecular structure of these three elements, on the basis of the 13 copies found at the inversion breakpoints plus 10 additional copies isolated ... | 2005 | 15695364 |
| evolutionary turnover of two pbum satellite dna subfamilies in the drosophila buzzatii species cluster (repleta group): from alpha to alpha/beta arrays. | the pbum satellite dna family was studied in seven drosophila species from the buzzatii cluster (within the large drosophila repleta group). the pbum repeats are slightly at-rich and show high levels of intraspecific sequence homogeneity. the pbum family can be divided into two subfamilies. the pbum-1 subfamily consists of tandemly arranged repetition units of approximately 190 bp, termed alpha. alpha repeats were found in a high copy number in the genome of d. buzzatii, d. serido and d. antonie ... | 2005 | 15777676 |
| conservation of regulatory sequences and gene expression patterns in the disintegrating drosophila hox gene complex. | homeotic (hox) genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis of metazoans. the mechanistic explanation for this colinearity has been elusive, and it may well be that a single and universal cause does not exist. the hox-gene complex (hom-c) has been rearranged differently in several drosophila species, producing a striking diversity of hox gene organizations. we investigated the genomic and functional consequences of the two h ... | 0 | 15867430 |
| a bac-based physical map of the drosophila buzzatii genome. | large-insert genomic libraries facilitate cloning of large genomic regions, allow the construction of clone-based physical maps, and provide useful resources for sequencing entire genomes. drosophila buzzatii is a representative species of the repleta group in the drosophila subgenus, which is being widely used as a model in studies of genome evolution, ecological adaptation, and speciation. we constructed a bacterial artificial chromosome (bac) genomic library of d. buzzatii using the shuttle v ... | 2005 | 15930498 |
| phylogeny and molecular evolution of the drosophila hydei subgroup (drosophila repleta group) inferred from the xanthine dehydrogenase gene. | the hydei subgroup (drosophila repleta group) consists of seven species divided into two complexes: bifurca and hydei, whose phylogenetic relationships are not well understood. to evaluate the molecular phylogeny of this subgroup, we analyzed 2085 bp of coding sequence of the xanthine dehydrogenase gene in six available species of the hydei subgroup, with drosophila buzzatii and drosophila mulleri as an outgroup. for phylogenetic reconstruction we adopted a maximum-likelihood framework, based on ... | 2005 | 15935705 |
| altitudinal variation for stress resistance traits and thermal adaptation in adult drosophila buzzatii from the new world. | multiple stress resistance traits were investigated in the cactophilic fly drosophila buzzatii. adults from seven populations derived from north-western argentina were compared with respect to traits relevant for thermal stress resistance and for resistance to other forms of environmental stress. the populations were collected along an altitudinal gradient spanning more than 2000 m in height, showing large climatic differences. the results suggest that knock-down resistance to heat stress, desic ... | 2005 | 16033554 |
| cactophilic drosophila in south america: a model for evolutionary studies. | the drosophila buzzatii cluster is composed of seven cactophilic species and their known geographical distribution encompasses the open vegetation diagonal, which includes the morphoclimatic domains of the caatinga, chaco and cerrado, which are situated between the amazon and the atlantic forests. besides these areas, these cactophilic species are also found in a narrow strip along the atlantic coast from northeastern brazil to the southern tip of the country. the hypothesis of vicariant events, ... | 2006 | 16502085 |
| climatic adaptation of drosophila buzzatii populations in southeast australia. | variation in 19 traits possibly relevant for thermal adaptation was studied in 11 populations of drosophila buzzatii collected in southeast australia. using stepwise multiple regression, the variation was compared to variation in geographic coordinates and to a set of climatic variables estimated for each collection site. for 13 of the traits, a significant part of the variation was explained by climatic variables and/or geographic coordinates, suggesting directional selection for adaptation to ... | 2006 | 16622471 |
| genotype by environment interactions in viability and developmental time in populations of cactophilic drosophila. | the genetic and ecological basis of viability and developmental time differences between drosophila buzzatii and d. koepferae were analysed using the isofemale line technique. several isofemale lines were sampled from pairs of allopatric/sympatric populations of each species. flies were reared in media prepared with decaying tissues of two of the main natural cactus hosts of each species. this experimental design enabled us to evaluate the relative contribution of phenotypic plasticity, genetic ... | 2006 | 16674586 |
| reproductive relationships and degree of synapsis in the polytene chromosomes of the drosophila buzzatii species cluster. | the process of speciation occurs through the evolution of any of several forms of reproductive isolation between taxa, including inviability of hybrids. in this work, strains derived from allopatric populations of drosophila buzzatii cluster species were experimentally crossed in order to evaluate their reproductive and cytogenetic relationships, and to contribute toward understanding the reproductive isolation in this group of sibling species. although intrastrain crosses were highly fertile, w ... | 2006 | 16710520 |
| aedeagus morphology as a discriminant marker in two closely related cactophilic species of drosophila (diptera; drosophilidae) in south america. | drosophila serido and d. antonietae are sibling species belonging to the drosophila buzzatii cluster. morphologically, they can only be discriminated by quantitative traits. in this paper we analyze the length and equalized average curvature of four regions of the aedeagus of d. antonietae and d. serido. specimens of d. serido and d. antonietae were classified correctly 96.74% of the time. based only on the variable that most contributed to the discrimination of the groups (equalized average cur ... | 2006 | 16710560 |
| abundance and chromosomal distribution of six drosophila buzzatii transposons: but1, but2, but3, but4, but5, and but6. | the abundance and chromosomal distribution of six class-ii transposable elements (tes) of drosophila buzzatii have been analyzed by southern blotting and in situ hybridization. these six transposons had been previously found at the breakpoints of inversions 2j and 2q ( 7 ) of d. buzzatii. these two polymorphic inversions were generated by an ectopic recombination event between two copies of galileo, a foldback element. the four breakpoints became hotspots for te insertions after the generation o ... | 2006 | 16773395 |
| patterns of variation in wing morphology in the cactophilic drosophila buzzatii and its sibling d. koepferae. | drosophila buzzatii and d. koepferae are two sibling species that breed on the necrotic tissues of several cactus species and show a certain degree of niche overlap. also, they show differences in several life history traits, such as body size and developmental time, which probably evolved as a consequence of adaptation to different host plants. in this work we investigate the ecological and genetic factors affecting wing morphology variation both within and between species. three wing traits we ... | 2006 | 16780528 |
| longevity differences among lines artificially selected for developmental time and wing length in drosophila buzzatii. | we assessed the indirect response of longevity in lines selected for wing length (wl) and developmental time (dt). longevity in selection lines was compared to laboratory control lines and the offspring of recently collected females. wild flies (w lines), flies from lines selected for fast development (f lines), and for fast development and large wing length (l lines) outlived control laboratory lines (c lines) and lines selected for fast development and short wing (s lines). the decline in long ... | 2006 | 16850224 |
| testing chromosomal phylogenies and inversion breakpoint reuse in drosophila. | a combination of cytogenetic and bioinformatic procedures was used to test the chromosomal phylogeny relating drosophila buzzatii with d. repleta. chromosomes x and 2, harboring most of the inversions fixed between these two species, were analyzed. first, chromosomal segments conserved during the divergence of the two species were identified by comparative in situ hybridization to the d. repleta chromosomes of 180 bac clones from a bac-based physical map of the d. buzzatii genome. these conserve ... | 2007 | 17028333 |
| altitudinal patterns for longevity, fecundity and senescence in drosophila buzzatii. | we tested for variation in longevity, senescence rate and early fecundity of drosophila buzzatii along an elevational transect in argentina, using laboratory-reared flies in laboratory tests performed to avoid extrinsic mortality. at 25 degrees c, females from lowland populations lived longer and had a lower demographic rate of senescence than females from highland populations. minimal instead of maximal temperature at the sites of origin of population best predicted this cline. a very different ... | 2006 | 17028942 |
| conservation of pbum-2 satellite dna sequences among geographically isolated drosophila gouveai populations from brazil. | in this study, we have compared 34 repetition units of pbum-2 satellite dna of individuals from six isolated populations of drosophila gouveai, a cactophilic member of drosophila buzzatii cluster (repleta group). in contrast to the results of previous morphological and molecular data, which suggest differentiation among the d. gouveai populations, the sequences and the cluster analysis of pbum-2 monomers showed that this repetitive element is highly conserved among the six d. gouveai populations ... | 2006 | 17028958 |
| molecular characterization and genomic distribution of isis: a new retrotransposon of drosophila buzzatii. | a new transposable element, isis, is identified as a ltr retrotransposon in drosophila buzzatii. dna sequence analysis shows that isis contains three long orfs similar to gag, pol and env genes of retroviruses. the orf1 exhibits sequence homology to matrix, capsid and nucleocapsid gag proteins and orf2 encodes a putative protease (pr), a reverse transcriptase (rt), an rnase h (rh) and an integrase (in) region. the analysis of a putative env product, encoded by the env orf3, shows a degenerated p ... | 2007 | 17039376 |
| the evolutionary history of drosophila buzzatii. xxxvi. molecular structural analysis of osvaldo retrotransposon insertions in colonizing populations unveils drift effects in founder events. | previous work on transposable element distribution in colonizing populations of drosophila buzzatii revealed a high frequency of occupancy in several chromosomal sites. two explanatory hypotheses were advanced: the founder hypothesis, by which founder genetic drift was responsible, and the unstable hypothesis that assigns this unusual distribution to bursts of transposition toward some chromosomal sites. here, we study the molecular structure of three euchromatic osvaldo clones isolated from sit ... | 2007 | 17151248 |
| molecular population genetics of the alpha-esterase5 gene locus in original and colonized populations of drosophila buzzatii and its sibling drosophila koepferae. | several studies have suggested that esterase-2 (est-2) may be the target of natural selection in the cactophilic fly drosophila buzzatii. in this work, we analyzed nucleotide variation in a fragment of alpha-esterase5 (alphae5), the gene encoding est-2, in original (argentinian) and colonized (australian) populations of d. buzzatii and in its sibling d. koepferae. estimates of nucleotide heterozygosity in d. buzzatii were similar in australia and argentina, although we detected a loss of singlet ... | 2007 | 17160646 |