| spv3 viruses of drosophila spiroplasmas. | the presence of spiroplasmas in the hemolymph of four drosophila willistoni group species has been shown to cause elimination of males from the progeny of infected females. these spiroplasmas, known as sex-ratio organisms (sros), are found in d. equinoxialis (esro), d. nebulosa (nsro), d. paulistorum (psro), and d. willistoni (wsro). in addition, a nonmale-lethal spiroplasma (his) has been found in the hemolymph of d. hydei. only the wsro has been cultivated. each of the drosophila spiroplasmas ... | 1987 | 3667220 |
| yeast succession in the amazon fruit parahancornia amapa as resource partitioning among drosophila spp. | the succession of yeasts colonizing the fallen ripe amapa fruit, from parahancornia amapa, was examined. the occupation of the substrate depended on both the competitive interactions of yeast species, such as the production of killer toxins, and the selective dispersion by the drosophilid guild of the amapa fruit. the yeast community associated with this amazon fruit differed from those isolated from other fruits in the same forest. the physiological profile of these yeasts was mostly restricted ... | 1995 | 8534092 |
| spiroplasma poulsonii sp. nov., a new species associated with male-lethality in drosophila willistoni, a neotropical species of fruit fly. | progenies from some wild-caught females of drosophila willistoni and three other sibling species are entirely female. the proclivity for production of unisexual female progeny by these flies was named the sex ratio (sr) trait and was originally thought to be genetic. however, experiments in the laboratory of donald f. poulson in the early 1960s demonstrated that this 'trait' was vertically transmitted and infectious, in that it could be artificially transferred by injection from infected females ... | 1999 | 10319483 |
| interference between "sex-ratio" agents of drosophila willistoni and drosophila nebulosa. | interference between two "sex-ratio" agents-that is, treponemalike spirochetes-of different origin, one from drosophila willistoni and the other from d. nebulosa, was demonstrated by experiments in vivo and in vitro. when the two sex-ratio agents were combined in females of the oregon-r strain of d. melanogaster, expression of the sex-ratio condition was temporarily interrupted. several lines of evidence indicate that a substance produced by the sex-ratio agent of d. nebulosa may kill or incapac ... | 1965 | 14220446 |
| interspecific transfer of the "sex-ratio" agent of drosophila willistoni in drosophila bifasciata and drosophila melanogaster. | the maternally transmitted "sex-ratio" condition in several species of drosophila appears to be due to infection by a microorganism of the genus treponema. drosophila bifasciata is an exception, since no microorganism has been found in the "sex-ratio" strains of this species. normal d. bifasciata can be infected by injection of the hemolymph of a "sex-ratio" strain of d. willistoni containing treponemas. the progenies of the infected d. bifasciata, up to and including the f(4) and f(5) generatio ... | 1965 | 14242033 |
| evolutionary dynamics of wau-like wolbachia variants in neotropical drosophila spp. | wolbachia bacteria are common intracellular symbionts of arthropods and have been extensively studied in drosophila. most research focuses on two old word hosts, drosophila melanogaster and drosophila simulans, and does not take into account that some of the wolbachia associations in these species may have evolved only after their fast global expansion and after the exposure to wolbachia of previously isolated habitats. here we looked at wolbachia of neotropical drosophila species. seventy-one l ... | 2006 | 16391124 |
| interspecific transmission of endosymbiotic spiroplasma by mites. | the occurrence of closely related strains of maternally transmitted endosymbionts in distantly related insect species indicates that these infections can colonize new host species by lateral transfer, although the mechanisms by which this occurs are unknown. we investigated whether ectoparasitic mites, which feed on insect haemolymph, can serve as interspecific vectors of spiroplasma poulsonii, a male-killing endosymbiont of drosophila. using spiroplasma-specific primers for pcr, we found that m ... | 2007 | 17443956 |
| only one esterase of drosophila melanogaster is likely to degrade juvenile hormone in vivo. | previously we identified juvenile hormone esterase (jhe) from drosophila melanogaster by the criteria that it showed both appropriate developmental expression and kinetics for juvenile hormone (jh). we also noted three further esterases of d. melanogaster with some jhe-like characteristics, such as a gqsag active site motif, a particular amphipathic helix, or close phylogenetic relationship with other jhes. in this study, these jhe-like enzymes were expressed in vitro and their kinetic parameter ... | 2007 | 17517331 |
| cultivation of the drosophila sex-ratio spiroplasma. | uncultivable for more than 25 years, the sex-ratio spiroplasma of drosophila willistoni grew in a tissue culture medium (h-2) containing an embryo-derived lepidopteran cell line (iplb-tn-r(2)). after adaptation, it grew in a cell-free h-2 medium. this success demonstrates the usefulness of cell culture systems for cultivation of fastidious microorganisms and facilitates study of the sex-ratio trait in drosophila. | 1986 | 17810745 |
| taxonomic boundaries, phylogenetic relationships and biogeography of the drosophila willistoni subgroup (diptera: drosophilidae). | the drosophila willistoni subgroup represents a complex with varying taxonomic levels. it encompasses d. willistoni and its five sibling species: d. equinoxialis, d. insularis, d. paulistorum, d. pavlovskiana and d. tropicalis. of these, d. equinoxialis, d. tropicalis and d. willistoni present differentiation at subspecific level, whereas d. paulistorum represents a superspecies, formed by six semispecies. despite this taxonomic and evolutionary complexity, many of these semi and subspecific tax ... | 2010 | 20049511 |
| Wolbachia pipientis is associated with different mitochondrial haplotypes in natural populations of Drosophila willistoni. | The prevalence of the endosymbiont Wolbachia pipientis and its effects on mitochondrial genetic diversity were analyzed in natural populations of Drosophila willistoni, a neotropical species recently infected. Total infection rate was 55% and no evidence was found that the Wolbachia infection decreased the diversity of mtDNA. Wolbachia was seen to be associated with different mitochondria, suggesting multiple horizontal transmission events and/or transmission paternal leakage of mitochondrial an ... | 2012 | 21945051 |
| enzyme variability in the drosophila willistoni group. v. genic variation in natural populations of drosophila equinoxialis. | | 2016 | 5084410 |
| enzyme variability in the drosophila willistoni group. 8. genetic differentiation and reproduction isolation between tow subspecies. | | 2014 | 4745485 |
| location of enzyme loci in chromosomes of drosophila willistoni. | | 2016 | 5026462 |
| comparative analysis of codon usage bias and codon context patterns between dipteran and hymenopteran sequenced genomes. | codon bias is a phenomenon of non-uniform usage of codons whereas codon context generally refers to sequential pair of codons in a gene. although genome sequencing of multiple species of dipteran and hymenopteran insects have been completed only a few of these species have been analyzed for codon usage bias. | 2012 | 22912801 |
| structural and sequence diversity of the transposon galileo in the drosophila willistoni genome. | galileo is one of three members of the p superfamily of dna transposons. it was originally discovered in drosophila buzzatii, in which three segregating chromosomal inversions were shown to have been generated by ectopic recombination between galileo copies. subsequently, galileo was identified in six of 12 sequenced drosophila genomes, indicating its widespread distribution within this genus. galileo is strikingly abundant in drosophila willistoni, a neotropical species that is highly polymorph ... | 2014 | 25218200 |
| evolutionary changes in gene expression, coding sequence and copy-number at the cyp6g1 locus contribute to resistance to multiple insecticides in drosophila. | widespread use of insecticides has led to insecticide resistance in many populations of insects. in some populations, resistance has evolved to multiple pesticides. in drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome p450 gene, cyp6g1. overexpression of cyp6g1 appears to have evolved in parallel in drosophila simulans, a sibling species of d. melanogaster, where it is also associated with insecticide resistance. however, i ... | 2014 | 24416303 |
| comparative gene expression analysis of dtg, a novel target gene of dpp signaling pathway in the early drosophila melanogaster embryo. | in the early drosophila melanogaster embryo, dpp, a secreted molecule that belongs to the tgf-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. here, we examined the expression pattern and transcriptional regulation of dtg, a new target gene of dpp signaling pathway that is required for proper amnioserosa differentiation. we showed that the expression of dtg was controlled by dpp and characterized a 524-bp e ... | 2014 | 24321690 |
| the effects of larval density on adult life-history traits in three species of drosophila. | there is evidence that longevity and starvation resistance are determined by a common genetic mechanism. starvation resistance in drosophila strongly correlates with both fat content and longevity, and is affected by density during rearing. in this study, we examine how three species, drosophila melanogaster, drosophila ananassae and drosophila willistoni, respond to three larval density treatments. starvation resistance after adult eclosion, and after 2 days of feeding, and longevity were exami ... | 2005 | 15664627 |
| naturally occurring variation in copia expression is due to both element (cis) and host (trans) regulatory variation. | significant differences in levels of copia [drosophila long terminal repeat (ltr) retrotransposon] expression exist among six species representing the drosophila melanogaster species complex (d. melanogaster, drosophila mauritiana, drosophila simulans, drosophila sechellia, drosophila yakuba, and drosophila erecta) and a more distantly related species (drosophila willistoni). these differences in expression are correlated with major size variation mapping to putative regulatory regions of the co ... | 1996 | 8692951 |
| the copia retrotransposon and horizontal transfer in drosophila willistoni. | the copia element is a retrotransposon that is hypothesized to have been horizontally transferred from drosophila melanogaster to some populations of drosophila willistoni in florida. here we have used pcr and southern blots to screen for sequences similar to copia element in south american populations of d. willistoni, as well as in strains previously shown to be carriers of the element. we have not found the canonical copia element in any of these populations. unlike the p element, which invad ... | 2011 | 21450134 |
| on the possible role of trna base modifications in the evolution of codon usage: queuosine and drosophila. | the best documented selection-based hypothesis to explain unequal usage of codons is based on the relative abundance of isoaccepting trnas. in unicellular organisms the most used codons are optimally translated by the most abundant trnas. the chemical bonding energies are affected by modification of the four traditional bases, in particular in the first anti-codon corresponding to the third codon position. one nearly universal modification is queuosine (q) for guanine (g) in trna(his), trna(asp) ... | 2010 | 20333371 |
| detection of p element transcripts in embryos of drosophila melanogaster and d. willistoni. | the p element is one of the most thoroughly studied transposable elements (te). its mobilization causes the hybrid dysgenesis that was first described in drosophila melanogaster. while studies of the p element have mainly been done in d. melanogaster, it is believed that drosophila willistoni was the original host species of this te and that p was transposed to the d. melanogaster genome by horizontal transfer. our study sought to compare the transcriptional behavior of the p element in embryos ... | 2009 | 19893894 |
| nucleotide substitution bias within the genus drosophila affects the pattern of proteome evolution. | the availability of complete genome sequences for 12 drosophila species provides an unprecedented resource for large-scale studies of genome evolution. in this study, we looked for correlated shifts in the patterns of genome and proteome evolution within the genus drosophila. specifically, we asked if the nucleotide composition of the drosophila willistoni genome--which is significantly less gc rich than the other 11 sequenced drosophila genomes--is reflected in an altered pattern of amino acid ... | 2009 | 20333198 |
| a complex suite of forces drives gene traffic from drosophila x chromosomes. | theoretical studies predict x chromosomes and autosomes should be under different selection pressures, and there should therefore be differences in sex-specific and sexually antagonistic gene content between the x and the autosomes. previous analyses have identified an excess of genes duplicated by retrotransposition from the x chromosome in drosophila melanogaster. a number of hypotheses may explain this pattern, including mutational bias, escape from x-inactivation during spermatogenesis, and ... | 2009 | 20333188 |
| molecular evolution of drosophila odorant receptor genes. | a total of 752 odorant receptor (or) genes, including pseudogenes, were identified in 11 drosophila species and named after their orthologs in drosophila melanogaster. the 813 or genes, including 61 from d. melanogaster, were classified into 59 orthologous groups that are well supported by gene phylogeny. by reconciling with the gene family phylogeny, we estimated the number of gene duplication/loss events and intron gain/loss events in the species phylogeny. we found that these events are parti ... | 2007 | 17331958 |
| first evidence of methylation in the genome of drosophila willistoni. | dna methylation has been studied abundantly in vertebrates and recent evidence confirms that this phenomenon could be disseminated among some invertebrates groups, including drosophila species. in this paper, we used the methylation-sensitive restriction endonuclease (msre) technique and southern blot with specific probes, to detect methylation in the drosophila willistoni species. we found differential cleavage patterns between males and females that cannot be explained by mendelian inheritance ... | 2007 | 17205375 |
| evidence for the recent horizontal transfer of long terminal repeat retrotransposon. | the evolutionary dynamics existing between transposable elements (tes) and their host genomes have been likened to an "arms race." the selfish drive of tes to replicate, in turn, elicits the evolution of host-mediated regulatory mechanisms aimed at repressing transpositional activity. it has been postulated that horizontal (cross-species) transfer may be one effective strategy by which tes and other selfish genes can escape host-mediated silencing mechanisms over evolutionary time; however, to d ... | 1999 | 10535972 |
| fate of dot chromosome genes in drosophila willistoni and scaptodrosophila lebanonensis determined by in situ hybridization. | one modification of the primitive karyotype of the drosophilidae is the absence of dot chromosomes. the origin of this modification is diverse. in some cases, the fate of the dot chromosomes can be directly inferred from cytogenetic analysis but in other cases a genetic or a combined molecular and cytogenetic analysis is needed, as occurs in drosophila willistoni and scaptodrosophila lebanonensis. we determined the location of four dot chromosome sequences in d. willistoni and s. lebanonensis us ... | 1998 | 9510510 |
| a simulation of p element horizontal transfer in drosophila. | experimental data suggest that the p transposable element has invaded the drosophila melanogaster genome after a horizontal transfer from the phylogenetically distant species drosophila willistoni. the differences between p element phylogeny and that of the drosophila genus could in part be explained by horizontal transfers. in vivo experiments show that p elements are able to transpose in the genomes of other drosophila species. this suggests that horizontal transmission of p elements could hav ... | 1997 | 9440282 |
| genomic distribution of p elements in drosophila willistoni and a search for their relationship with chromosomal inversions. | according to the recent-invasion hypothesis, drosophila melanogaster may have acquired its p elements in a fairly recent process of horizontal transmission between species. drosophila willistoni has been identified as the potential donor species in that transfer process. a most remarkable feature of d. willistoni is its extensive chromosomal polymorphism due to inversions-the adaptiveness of which has been the subject of many classical studies on evolutionary genetics. in this article, we furthe ... | 2009 | 8683096 |
| characterization of a cu/zn superoxide dismutase-encoding gene region in drosophila willistoni. | a cu/zn superoxide dismutase-encoding gene (sod) from drosophila willistoni was cloned and sequenced. the gene shows a typical structure for a fruit-fly sod gene, with a coding region of 462 bp in two exons separated by a 417-bp intron. comparison of the sod sequences from d. willistoni and d. melanogaster suggests that these species are only remotely related. downstream from the sod gene, there is an orf on the opposite strand that putatively encodes the last exon of an unidentified gene. the p ... | 1994 | 7926818 |
| possible horizontal transfer of drosophila genes by the mite proctolaelaps regalis. | there is strong inferential evidence for recent horizontal gene transfer of the p (mobile) element to drosophila melanogaster from a species of the drosophila willistoni group. one potential vector of this transfer is a semiparasitic mite, proctolaelaps regalis deleon, whose morphology, behavior, and co-occurrence with drosophila are consistent with the properties necessary for such a vector. southern blot hybridization, polymerase chain reaction (pcr) amplification, and dna sequencing showed th ... | 1991 | 1653453 |
| comparison of the concealed variability in drosophila willistoni with that in drosophila prosaltans. | | 1959 | 17247899 |
| dosage compensation of genes on the left and right arms of the x chromosome of drosophila pseudoobscura and drosophila willistoni. | we have investigated the occurrence of dosage compensation in d. willistoni and d. pseudoobscura, two species whose x chromosome is metacentric with one arm homologous to the x and the other homologous to the left arm of chromosome 3 of d. melanogaster. crude extracts were assayed for isocitrate dehydrogenase (xr), glucose-6-phosphate dehydrogenase (xl?), 6-phosphogluconate dehydrogenase (xl?), and alpha-glycerophosphate dehydrogenase (chromosome 2) in d. willistoni, and for esterase-5 (xr), glu ... | 1974 | 4455556 |
| drosophilid assemblages at different urbanization levels in the city of porto alegre, state of rio grande do sul, southern brazil. | the present study analyzed the drosophilid assemblages in different levels of urbanization in the city of porto alegre, rio grande do sul, brazil. collections were carried out in 2008 in three different environments: a highly urbanized area-"jardim botânico," a forested area with intermediary urbanization-"parque gabriel knijnik," and in a relatively well-preserved forested area, although threatened by the urban growth-"morro santana." in jardim botânico, 36 species belonging to four genera were ... | 2012 | 23950007 |
| effects of seasonality on drosophilids (insecta, diptera) in the northern part of the atlantic forest, brazil. | seasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. this study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the neotropical region and exotic ones. three preserved fragments of the northern atlantic forest were surveyed, where temperatures are above 20 °c throughout the year and rainfall regimes define two seasons (dry and rainy). ... | 2017 | 28249637 |
| postmating reproductive isolation between strains of drosophila willistoni. | speciation can occur through the presence of reproductive isolation barriers that impede mating, restrict cross-fertilization, or render inviable/sterile hybrid progeny. the d. willistoni subgroup is ideally suited for studies of speciation, with examples of both allopatry and sympatry, a range of isolation barriers, and the availability of one species complete genome sequence to facilitate genetic studies of divergence. d. w. willistoni has the largest geographic distribution among members of t ... | 2016 | 27268100 |
| ultrastructural features of spermatozoa and their phylogenetic application in zaprionus (diptera, drosophilidae). | the genus zaprionus consists of approximately 60 species of drosophilids that are native to the afrotropical region. the phylogenetic position of zaprionus within the drosophilidae family is still unresolved. in the present study, ultrastructural features of spermatozoa of 6 species of zaprionus as well as the species drosophila willistoni and scaptodrosophila latifasciaeformis were analyzed. the ultrastructure revealed that the species have the same flagellar ultrastructure. two mitochondrial d ... | 2016 | 26963134 |
| reassignment of drosophila willistoni genome scaffolds to chromosome ii arms. | drosophila willistoni is a geographically widespread neotropical species. the genome of strain gd-h4-1 from guadeloupe island (caribbean) was sequenced in 2007 as part of the 12 drosophila genomes project. the assembled scaffolds were joined based on conserved linkage and assigned to polytene chromosomes based on a handful of genetic and physical markers. this paucity of markers was particularly striking in the metacentric chromosome ii, comprised two similarly sized arms, iil and iir, tradition ... | 2015 | 26438290 |
| hybrid male sterility between drosophila willistoni species is caused by male failure to transfer sperm during copulation. | the biological concept of species stresses the importance of understanding what mechanisms maintain species reproductively isolated from each other. often such mechanisms are divided into premating and postmating, with the latest being the result of either prezygotic or postzygotic isolation barriers. drosophila willistoni quechua and drosophila willistoni willistoni are two subspecies that experience reproductive isolation. when a d. w. quechua female is crossed with a d. w. willistoni male, th ... | 2015 | 25925738 |
| cytogenetic mapping of the muller f element genes in drosophila willistoni group. | comparative genomics in drosophila began in 1940, when muller stated that the ancestral haploid karyotype of this genus is constituted by five acrocentric chromosomes and one dot chromosome, named a to f elements. in some species of the willistoni group such as drosophila willistoni and d. insularis, the f element, instead of a dot chromosome, has been incorporated into the e element, forming chromosome iii (e + f fusion). the aim of this study was to investigate the scope of the e + f fusion in ... | 2014 | 25134938 |
| reevaluating the infection status by the wolbachia endosymbiont in drosophila neotropical species from the willistoni subgroup. | infections by the endosymbiotic bacterium wolbachia developed a rapid global expansion within old world drosophila species, ultimately infecting also neotropical species. in this sense, screenings are necessary to characterize new variants of wolbachia or new hosts, and also in order to map the dynamics of already known infections. in this paper, we performed a double screening approach that combined dot-blot and pcr techniques in order to reevaluate the infection status by wolbachia in species ... | 2013 | 23906981 |
| three decades of studies on chromosomal polymorphism of drosophila willistoni and description of fifty different rearrangements. | drosophila willistoni (insecta, diptera) is considered a paradigm for evolutionary studies. their chromosomes are characterized by multiple paracentric inversions that make it hard to identify and describe chromosomal polymorphisms. in the present report we attempted to systematize the description of all the 50 inversions found in the last three decades, since we have been studying the chromosomes of several individuals of 30 different populations, including the one used in the genome sequencing ... | 2012 | 23411997 |
| new drosophila p-like elements and reclassification of drosophila p-elements subfamilies. | genomic searches for p-like transposable elements were performed (1) in silico in the 12 available drosophila genomes and (2) by pcr using degenerate primers in 21 neotropical drosophila species. in silico searches revealed p-like sequences only in drosophila persimilis and drosophila willistoni. sixteen new p-like elements were obtained by pcr. these sequences were added to sequences of previously described p-like elements, and a phylogenetic analysis was performed. the subfamilies of p-element ... | 2012 | 22610468 |
| nonrecombining genes in a recombination environment: the drosophila "dot" chromosome. | rate of recombination is a powerful variable affecting several aspects of molecular variation and evolution. a nonrecombining portion of the genome of most drosophila species, the "dot" chromosome or f element, exhibits very low levels of variation and unusual codon usage. one lineage of drosophila, the willistoni/saltans groups, has the f element fused to a normally recombining e element. here, we present polymorphism data for genes on the f element in two drosophila willistoni and one d. insul ... | 2011 | 20940345 |
| sex-specific methylation in drosophila: an investigation of the sophophora subgenus. | epigenetic phenomena have been widely characterized in the genomes of vertebrates and dna methylation is a key mechanism of epigenetic regulation. the dna methylation systems of invertebrates and vertebrates show several notable differences. however, the evolutionary implications of those differences only recently began to be revealed. our study investigated the recurrence of sex-specific methylation, as previously described for the species drosophila willistoni, in other species of the sophopho ... | 2010 | 20640488 |
| male meiotic chromosomes of five species of the drosophila willistoni group. | | 2006 | 17362352 |
| chromosomal evolution of sibling species of the drosophila willistoni group. i. chromosomal arm iir (muller's element b). | the phylogenetic relationships among nine entities of drosophila belonging to the d. willistoni subgroup were investigated by establishing the homologous chromosomal segments of iir chromosome, muller's element b (equivalent to chromosome 2l of d. melanogaster). the sibling species of the d. willistoni group investigated include d. willistoni, d. tropicalis tropicalis, d. tropicalis cubana, d. equinoxialis, d. insularis and four semispecies of the d. paulistorum complex. the phylogenetic relatio ... | 2006 | 16502086 |
| mating activity of yellow and sepia drosophila willistoni mutants. | by analyzing the mating activity of newly isolated yellow and sepia mutants of drosophila willistoni no difference in behavior between sepia and wild-type flies were observed, whereas yellow males were less successful than wild-type males when competing for females. these results are in agreement with those reported for other drosophila species. d. willistoni was different in the 'females-competing' crosses because wild-type males mated more frequently with wild-type females whereas yellow males ... | 2005 | 16098685 |
| evolution of p elements in natural populations of drosophila willistoni and d. sturtevanti. | to determine how population structure of the host species affects the spread of transposable elements and to assess the strength of selection acting on different structural regions, we sequenced p elements from strains of drosophila willistoni and drosophila sturtevanti sampled from across the distributions of these species. elements from d. sturtevanti exhibited considerable sequence variation, and similarity among them was correlated to geographic distance between collection sites. by contrast ... | 2004 | 15579688 |
| meiosis in drosophila willistoni and d. paulistorum females. | | 2004 | 15383077 |
| dynamics and function of intron sequences of the wingless gene during the evolution of the drosophila genus. | to understand the function and evolution of genes with complex patterns of expression, such as the drosophila wingless gene, it is essential to know how their transcription is regulated. however, extracting the relevant regulatory information from a genome is still a complex task. we used a combination of comparative genomics and functional approaches to identify putative regulatory sequences in two introns (1 and 3) of the wingless gene and to infer their evolution. comparison of the sequences ... | 2012 | 15330865 |
| analysis of a shift in codon usage in drosophila. | in order to gain further insight into a shift in codon usage first observed in drosophila willistoni we have analyzed seven genes in six species in the lineage leading to d. willistoni. this lineage contains the willistoni and saltans species groups. sequences were obtained from genbank or newly sequenced for this study. all species studied showed significant difference in codon usage compared to d. melanogaster for about one third of all amino acids. within the willistoni/saltans lineage, codon ... | 2003 | 15008418 |
| vege and mar: two novel hat mite families from drosophila willistoni. | two novel families of miniature inverted repeat transposable elements (mites), vege and mar, are described from drosophila willistoni. based on their structures, both element families are hypothesized to belong to the hat superfamily of transposable elements. both elements have perfect, inverted terminal repeats and 8-bp target site duplications and were found to have inserted within fixed copies of nonautonomous p elements. vege is present in all studied d. willistoni populations and appears to ... | 2003 | 12598681 |
| body size and mating success in drosophila willistoni are uncorrelated under laboratory conditions. | mating activity and wing length were investigated in the f1; progeny of drosophila willistoni females collected in the field to examine any possible relationship between body size and mating success. the flies were observed in a mating chamber under laboratory conditions. no significant differences in wing length were observed between copulating and noncopulating flies, and there was no significant correlation between wing length and copulation latency for both males and females. these results t ... | 2001 | 11910127 |
| a temporal analysis of sexual activity in a natural population of drosophila willistoni. | we have analyzed the mating activity of f1 flies in mating chamber from five samples of wild drosophila willistoni females. the files were collected from an area (in south brazil) that has well-defined seasons and considerable variation in temperature and in the abundance of drosophilids. we estimated copulation frequency at first five minutes of observation, copulation frequency at ninety minutes of observation and copulation latency. we did not observe differences in the total copulation frequ ... | 2000 | 11433965 |
| developmental isolation and subsequent adult behavior of drosophila paulistorum. v. survey of six sibling species. | in an investigation into the effects of developmental isolation from all conspecifics, the drosophila willistoni group of six sibling species responded to differing degrees: all six are reproductively isolated from d. paulistorum, the tester species. drosophila pavlovskiana, a narrow endemic, proved the most vulnerable, responding by reducing its adult sexual isolation, if eggs, any instar, and sometimes even pupae were socially isolated. to lesser degrees, d. tropicalis and d. willistoni both p ... | 1999 | 10371760 |
| adh nucleotide variation in drosophila willistoni: high replacement polymorphism in an electrophoretically monomorphic protein. | drosophila willistoni was the subject of intensive allozyme studies and the locus coding for alcohol dehydrogenase (adh) was found to be virtually monomorphic. dna sequence analysis of 18 alleles throughout the distribution of the species has revealed six replacement polymorphisms. the ratio of replacement to silent polymorphisms is higher in d. willistoni than in any other drosophila species studied for adh nucleotide variation. also in contrast to other species, the variation in introns and no ... | 1997 | 9302316 |
| interspecific and intraspecific comparisons of the period locus in the drosophila willistoni sibling species. | the period (per) locus has received much attention in molecular evolution studies because it is one of the best studied "behavioral genes" and because it offers insight into the evolution of repetitive sequences. we studied most of the coding region of per in drosophila willistoni and confirmed previously observed patterns of conservation and divergence among distantly related species. five regions are so highly diverged that they cannot be aligned, whereas a region encompassing the pas domain i ... | 1997 | 9214747 |
| molecular evolution of the paired gene in drosophila: cloning and characterization of the partial paired gene from drosophila willistoni. | a partial paired gene of drosophila willistoni containing the paired box and extended homeo box was amplified by pcr and the nucleotide sequence of 1141 bp was determined. comparison of the paired genes in d. willistoni and d. melanogaster showed that the proportions of identical nucleotide sites in the coding region and identical amino acid sites were 73.8 and 86.5%, respectively. the amino acid sites in the n-terminal region, the paired box, and the extended homeo box were 88.5, 95.3, and 98.6 ... | 1996 | 9126670 |
| localization of the cu/zn superoxide dismutase gene in the drosophila willistoni species group by in situ hybridization. | due to the physiological importance of its product, the cu/zn superoxide dismutase enzyme, the gene coding for this enzyme was mapped in five species of the drosophila willistoni subgroup and in d. nebulosa by in situ hybridization using d. melanogaster as a control. the results indicate that this locus is located on the xr chromosomal arm of the five sibling species and on the xl chromosomal arm of d. nebulosa, suggesting the occurrence of a pericentric inversion before the separation of these ... | 1994 | 7774289 |
| evolution of the adh locus in the drosophila willistoni group: the loss of an intron, and shift in codon usage. | we report here the dna sequence of the alcohol dehydrogenase gene (adh) cloned from drosophila willistoni. the three major findings are as follows: (1) relative to all other adh genes known from drosophila, d. willistoni adh has the last intron precisely deleted; pcr directly from total genomic dna indicates that the deletion exists in all members of the willistoni group but not in any other group, including the closely related saltans group. otherwise the structure and predicted protein are ver ... | 1993 | 8336545 |
| population genetics in the american tropics xvi. data on partial dominance of recessives in drosophila willistoni. | through a series of genetic load studies made on 1) samples of drosophila willistoni from two sites in mesitas, colombia, it was found that the relative contributions to the total, subvital and lethal loads reflect lethal equivalences (b/a) ratios which support more the balancing theory of population structure than the neutralist theory. moreover, measurements of population size have revealed the existance of very small demes in local populations. under such conditions we have calculated extreme ... | 1982 | 24270342 |
| boundary-layer model for the population dynamics of single species. | we develop a new discrete-time model, called the boundary-layer model, to describe the dynamics of single species that have a capacity for fast growth at very low population densities. the model explicitly separates the dynamics of the population at very low densities (within the "boundary layer") and at high densities. the boundary-layer model provides a better fit than other models such as the logistic or the theta model to data from experimental populations of drosophila willistoni and d. pse ... | 1981 | 16592994 |
| satellite dna sequences and reproductive isolation in the drosophila willistoni group. | | 1980 | 6249635 |
| population genetics in the american tropics : xi. seasonal and temporal variations in relative frequencies of species belonging to the willistoni group in colombia. | the authors examined seasonal and plant food preferences of members of drosophila willistoni group in three different ecosystems in colombia. the results show that there are seasonal preferences as well as food preferences. furthermore, there exist clear cut temporal (hours of the day) selection which would make possible the sympatric exploitation of equal ecological niches. comparisons with melanogaster species and with obscura species group are also made. | 1977 | 28308956 |
| transmission of nosema kingi to offspring of drosophila willistoni during copulation. | transmission of the microsporidian nosema kingi to offspring of drosophila willistoni during copulation was investigated. offspring from matings of infected females and non-infected males, infected males and non-infected females, and both infected females and males were parasitized with n. kingi. 28% of the offspring were infected when the parents mated immediately after exposure to the parasite. however, 43--93% of the offspring were infected with the microsporidian when copulation was delayed ... | 1977 | 413272 |
| testing for selective neutrality of electrophoretically detectable protein polymorphisms. | the statistical assessment of gene-frequency data on protein polymorphisms in natural populations remains a contentious issue. here we formulate a test of whether polymorphisms detected by electrophoresis are in accordance with the stepwise, or charge-state, model of mutation in finite populations in the absence of selection. first, estimates of the model parameters are derived by minimizing chi-square deviations of the observed frequencies of genotypes with alleles (0,1,2...) units apart from t ... | 1976 | 1001883 |
| population differentiation under the charge state model. | the extent of divergence between partially isolated sub-populations for electrophoretically detectable alleles was formulated assuming the island model of migration and the charge state model of mutation. at equilibrium the ratio of the variance of charge between the means of k different islands to the average within-island variance of charge was shown to be approximately 4nemk2/(k-1)2 where ne is the effective size of each island population and m is the migration rate. this ratio was calculated ... | 1975 | 1213272 |
| analysis of incipient reproductive isolation within a species of drosophila. | drosophila willistoni and its subspecies quechua are morphologically indistinguishable, but differ in relative frequencies of certain allozyme genes. the cross quechua female x willistoni male produces nearly or completely sterile males, while the reciprocal cross gives fertile males. hybrid females are fertile. analysis of the sterility with the aid of chromosomes marked with mutant genes shows that the second and x-chromosomes have major and third chromosomes minor effects. backcross males of ... | 1975 | 1059154 |
| the evolution of selectively similar electrophoretically detectable alleles in finite natural populations. | most of the models of population genetics are not realistic when applied to data on electrophoretic variants of proteins because the same net charge may result from any of several amino acid combinations. in the absence of realistic models they have, however, been widely used to test competing hypotheses about the origin and maintenance of genetic variation in populations. in this paper i present a general method for determining probability generating functions for electrophoretic state differen ... | 1975 | 1132689 |
| genetic differentiation within and between species of the drosophila willistoni group. | we describe allelic variation at 28 loci in six caribbean populations of four sympatric species of drosophila. within any one species the allelic frequencies are very similar from population to population, although there is evidence of local as well as regional genetic differentiation. the genetic distance is greater between populations from different islands than between populations of the same island. when the allelic frequencies are compared between different species, a remarkable pattern app ... | 1974 | 4362644 |
| apparent selection of enzyme alleles in laboratory populations of drosophila. | twelve laboratory populations of recently collected drosophila willistoni were begun with different frequencies of alleles at three enzyme loci, six populations at 25 degrees and six at 19 degrees . periodic sampling of the populations allowed monitoring of the frequency changes in allozymes over time.-at lap-5 (a locus coding for leucine amino peptidase), three alleles converged to the same frequencies in all populations at both temperatures. the apparent equilibrium frequency of the major alle ... | 1973 | 4775750 |
| radioresistance of a natural population of drosophila willistoni living in a radioactive environment. | | 1973 | 4796403 |
| enzyme variability in the drosophila willistoni group. vi. levels of polymorphism and the physiological function of enzymes. | | 1972 | 4646770 |
| enzyme variability in the drosophila willistoni group. 3. amounts of variability in the superspecies, d. paulistorum. | the semispecies composing the superspecies, drosophila paulistorum, have been analyzed for genetic variation at 17 enzyme loci. on the average a population of d. paulistorum is polymorphic for 55-67% of its loci and an average individual is heterozygous at 21% of its loci. the pattern of genetic variability found supports the hypothesis that allozyme variation is maintained in natural populations by some form of balancing selection. evidence is presented which supports the hypothesis that glucos ... | 1972 | 5013892 |
| enzyme variability in the drosophila willistoni group. iv. genic variation in natural populations of drosophila willistoni. | we describe allelic variation at 28 gene loci in natural populations of d. willistoni. seventy samples were studied from localities extending from mexico and florida, through central america, the west indies, and tropical south america, down to south brazil. at least several hundred, and often several thousand, genomes were sampled for each locus. we have discovered a great deal of genetic variation. on the average, 58% loci are polymorphic in a given population. (a locus is considered polymorph ... | 1972 | 5013890 |
| genetic polymorphisms in varied environments. | thirteen experimenital populationis of drosophila willistoni were maintained in cages, in some of which the environments were relatively constant and in others varied. after 45 weeks, the populations were assayed by gel electrophoresis for polymorphisms at 22 protein loci. the average heterozygosity per individual and the average unmber of alleles per locus were higher in populations maintained in heterogeneous environments than in populations in more constant enviroments. | 1971 | 5120090 |
| polymorphisms in continental and island populations of drosophila willistoni. | a comparative study of genic allozyme and chromosomal polymorphisms in four continental (south american) and six oceanic island (west indies) populations of drosophila willistoni has been made. the pattern of genic polymorphism is closely similar in all populations. although regional and local differences in gene frequencies are found, generally the same alleles occur at high, intermediate, and low frequencies in all populations. an average individual is heterozygous at 18.4 and 16.2% of its loc ... | 1971 | 5289881 |
| [study of sterility among different progeny of drosophila willistoni]. | | 1971 | 5173319 |
| competition between strains of drosophila willistoni and d. pseudoobscura. | | 1971 | 5546669 |
| competitive fitness in experimental populations of drosophila willistoni. | | 1971 | 5112158 |
| enzyme variability in the drosophila willistoni group. i. genetic differentiation among sibling species. | we have studied by gel electrophoresis the variability of 14 structural genes in four sibling species, drosophila willistoni, d. paulistorum, d. equinoxialis, and d. tropicalis. samples of about 30 populations from different parts of the distribution areas of each species were examined. genetic variants are found at every locus; 67% of the loci are polymorphic, having two or more alleles, the rarer of which has a frequency of 5% or higher. the gene frequencies are fairly uniform over the distrib ... | 1970 | 5272313 |
| crossing-over between heterozygous inversions and its relation with polymorphism in "drosophila willistoni". | | 1968 | 5713824 |
| recombination in drosophila willistoni. | | 1968 | 5245954 |
| chromosomal diseases in "drosophila willistoni" sturtevant. | | 1967 | 5596566 |
| on the origin of new lethal chromosomes and its rate in laboratory populations of drosophila willistoni. | | 1966 | 5972699 |
| the nature of lethals in drosophila willistoni. | | 1965 | 5863908 |
| interspecific hybridisation between the six cryptic species of drosophila willistoni group. | | 1965 | 14300932 |
| inbreeding and the mutational and balanced loads in natural populations of drosophila willistoni. | | 1964 | 14239790 |
| interspecific transfer of the "sex-ratio" condition from drosophila willistoni to d. melanogaster. | | 1963 | 17248174 |
| transfer of the "sexratio" factor in drosophila willistoni by ingestion. | thirty-nine females from a normal strain of drosophila willistoni were kept in bottles containing a drop of a supernatant of a macerate of "sex-ratio" females of the same species. two of these females acquired the "sex-ratio" condition and transmitted it to their progenies. | 1962 | 13877008 |
| developmental effects of the sexratio agent in embryos of drosophila willistoni. | | 1962 | 14023403 |
| distribution of "sex-ratio" agent in tissues of drosophila willistoni. | | 1961 | 14496145 |
| release of genetic variability through recombination. vi. drosophila willistoni. | | 1961 | 14459670 |
| some components of adaptive values of heterzygous drosophila willistoni from irradiated natural populations. | | 1961 | 14470147 |
| genetic effects of gamma-radiation on natural populations of drosophila willistoni. | | 1961 | 14007490 |
| chromosomal polymorphism decrease due to gamma-radiation on natural populations of drosophila willistoni. | | 1961 | 13881289 |
| synthetic sterility in drosophila willistoni. | | 1960 | 16590679 |