Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the effects of artificial selection for slow mating in drosophila simulans. i. the behavioural changes. | 1968 | 5639888 | |
| the genetics of an acid phosphatase in drosophila melanogaster and drosophila simulans. | 1966 | 5919327 | |
| an abnormal sex ratio in drosophila simulans. | 1967 | 6035593 | |
| interspecific dna transformation in drosophila. | a dna fragment that includes the wild-type rosy (ry+) gene of drosophila melanogaster has been introduced by microinjection into the germ line of the reproductively isolated species drosophila simulans and incorporated into the d. simulans genome. transformation was mediated by the transposable element p, which occurs in the genome of most natural populations of d. melanogaster but not in d. simulans. rubin and spradling [rubin, g.m. & spradling, a.c. (1982) science 218, 348-353] have previously ... | 1984 | 6095302 |
| origin and direction of replication in mitochondrial dna molecules from the genus drosophila. | mitochondrial dna (mtdna) obtained from ovaries of drosophila simulans, d. mauritiana, d. takahashii, d. yakuba and d. virilis was examined by electron microscopy. from a consideration of the structural properties of replicative intermediates, it was concluded that in mtdna molecules of each species, synthesis on one strand can be up to 97% complete before synthesis on the complementary strand is initiated. mtdna molecules of each species contain a single a+t-rich region which shows species-spec ... | 1980 | 6253922 |
| intraspecific diversity of nucleotide sequences within the adenine + thymine-rich region of mitochondrial dna molecules of drosophila mauritiana, drosophila melanogaster and drosophila simulans. | mitochondrial dna (mtdna) molecules from drosophila mauritiana, d. melanogaster, and d. simulans contain a single adenine + thymine (a+t)-rich region, which is similarly located in all molecules, but varies in size among these species. using agarose gel electrophoresis and electron microscopy, a difference in occurrence of one ecori site, and a difference in size (approximately 0.7 kb) of the a+t-rich regions was found between mtdna molecules of flies of two female lines of d. mauritiana. in het ... | 1980 | 6258143 |
| the 5s ribosomal genes in the drosophila melanogaster species subgroup. nucleotide sequence of a 5s unit from drosophila simulans and drosophila teissieri. | the 5s genes of the eight species of the d. melanogaster subgroup have been mapped. the spacers, in contrast with coding regions, differ markedly between most species. one 5s gene unit has been sequenced for both d. simulans and d. teissieri. the mature 5s rna region in these two species is identical to the corresponding region of d. melanogaster. only 5 nucleotide variations occur between the d. melanogaster and d. simulans 5s gene spacers. the spacer in d. teissieri is very different. only two ... | 1984 | 6320111 |
| variation in response to co2 in drosophila melanogaster and d. simulans. | a type of slow-recovery from high temperature co2 exposure is a wild-type characteristic of drosophila simulans. species hybrids of wild-type d. melanogaster and d. simulans have intermediate recovery times. the response to nitrogen exposure at both high and low temperatures is the same for the two species suggesting that the observed co2 response is more than just anoxia. since there is no female bias in hybrids, and since injections of d. simulans extract into d. melanogaster produced no incre ... | 2013 | 6408161 |
| meiosis and early cleavage in drosophila melanogaster eggs: effects of the claret-non-disjunctional mutation. | the claret-non-disjunctional (cand) mutation is a female-specific mutation in drosophila melanogaster, which causes a high frequency of mortality (89--90%) in eggs laid by the homozygous females. among the progeny that survive to the adult stage, greater than 50% are aneuploid and/or mosaic for the x and number 4 chromosomes. the genetic studies of cand indicate that it is homologous to the claret mutation (ca-simulans) in drosophila simulans. the cytological effect of the cand mutation on meios ... | 1983 | 6413518 |
| regulatory gene evolution: adaptive differences in expression of alcohol dehydrogenase in drosophila melanogaster and drosophila simulans. | in drosophila melanogaster x d. simulans hybrids, the alcohol dehydrogenase (adh) electromorphs characteristic of the two parents display tissue- and stage-specific differences in relative level of expression. this implies distinct cis-acting regulatory elements associated with the respective adh alleles. these cis-acting elements account in part, but not completely, for markedly different overall patterns of adh expression in the two species. the regulatory patterns seem to be adaptively signif ... | 1984 | 6429088 |
| nucleotide sequence comparison of the adh gene in three drosophilids. | the alcohol dehydrogenase (adh) gene has been isolated from drosophila simulans and d. mauritiana by screening lambda clone libraries of each with a previously cloned adh gene from d. melanogaster. the isolated lambda clones were subcloned and partially sequenced to determine the relatedness of these species and to examine details of evolutionary change in the structure of the adh gene. we report the sequence of the first 704 nucleotides of each gene as well as 127 bases in the 5' untranslated r ... | 1984 | 6429340 |
| olfactory responses to alcohols by adults of sympatric populations of drosophila melanogaster and drosophila simulans. | 1984 | 6435598 | |
| genetic basis of male sterility in hybrids between two closely related species of drosophila. | drosophila simulans and drosophila mauritiana are closely related sibling species, the former cosmopolitan and the latter restricted to the small oceanic island of mauritius. genetic analysis of male sterility in hybrids between these species shows that at least five loci (one on each chromosome arm) are responsible for this reproductive isolation. this is the most loci that could have been detected with the techniques used and implies that the true genetic divergence for sterility is even great ... | 1984 | 6589604 |
| localization of the ribosomal rna genes in drosophila simulans. | in situ hybridization of cloned rrna genes from drosophila melanogaster to d. simulans metaphase chromosomes shows that in the tested wild type strains both sex chromosomes contain a nucleolus organizer region. silver grain counts support the published data that the x chromosomal rrna gene number is significantly higher than the y chromosomal. | 1980 | 6772417 |
| analysis of courtship sequences of the hybrids between drosophila melanogaster and drosophila simulans. | several transitions between sequential male courtship elements were analyzed for drosophila melanogaster, its close relative d. simulans, and two types of hybrid males. hybrid males from special reciprocal crosses did not differ. while d. melanogaster and d. simulans males differed markedly for the majority of transitions studied, hybrid males showed no consistent pattern with the parent species, being indistinguishable from d. simulans males, indistinguishable from d. melanogaster, or intermedi ... | 1980 | 6779788 |
| purification and enzyme stability of alcohol dehydrogenase from drosophila simulans, drosophila virilis and drosophila melanogaster adhs. | three alcohol dehydrogenases from drosophila simulans, drosophila virillis and drosophila melanogaster adhs (which possesses an alloenzyme with slow electrophoretic mobility) were purified essentially to homogeneity. the purification procedure involves a new step of affinity chromatography, which efficiently lowers the amount of contaminants in the final preparation, producing a very stable enzyme. the purification procedure developed consists of a salmine sulphate precipitation, two cm-sepharos ... | 1980 | 6779810 |
| comparative studies of allozyme loci in drosophila simulans and drosophila melanogaster. i. three dipeptidase loci. | genetic variation at three dipeptidase loci (dip-a, dip-b, and dip-c) in drosophila simulans was analyzed by starch gel electrophoresis. dip-a was found to be polymorphic in four populations, while dip-b and dip-c were found to be polymorphic in one. the numbers of different alleles found at each respective locus were: dip-a, two; dip-b, two; and dip-c, three. dip-a was genetically mapped at 57.9 on the second chromosome, and dip-b and dip-c at 80.9 and 87.9 on the third chromosome, respectively ... | 1981 | 6784720 |
| hybrid sterility in drosophila simulans: relationships with the hybrid dysgenesis syndrome in drosophila melanogaster. | 1981 | 6790477 | |
| determination of some biochemical and structural features of alcohol dehydrogenases from drosophila simulans and drosophila virilis. comparison of their properties with the drosophila melanogaster adhs enzyme. | the biochemical properties of the enzyme alcohol dehydrogenase of two different drosophila species, drosophila simulans and drosophila virilis, were studied and compared with those of drosophila melanogaster adhs enzyme. all of them consist of two identical subunits of molecular weight 27800 and share significant similarities in function. the substrate specificities of these enzymes were characterized and km(app.) and vmax.(app.) values were calculated. all these alcohol dehydrogenases show grea ... | 1981 | 6796069 |
| light-dependent pupation site preferences in drosophila. ii. drosophila melanogaster and drosophila simulans. | drosophila melanogaster prefers to pupate in the dark, while its sibling species, d. simulans, prefers the light when the species are tested in isolation and when cultured and tested together. reciprocal interspecific hybridizations were carried out and the f1 individuals were tested. progeny from the cross of d. melanogaster females with d. simulans males chose pupations sites exactly intermediate between those of the two parental species, while the reciprocal-cross offspring preferred light pu ... | 1981 | 6803758 |
| pupation site selection in drosophila simulans. | 1983 | 6838459 | |
| genetic analysis of drosophila vitellogenesis: a molecular weight variant of yolk polypeptide-2 in drosophila simulans. | 1980 | 6930533 | |
| estimation of genetic variability in natural populations of drosophila simulans by two-dimensional and starch gel electrophoresis. | genic variation in natural populations of drosophila simulans was surveyed using allozymic and two-dimensional electrophoretic techniques. consistent with some previous reports, allozymic heterozygosity appeared lower than in the sibling species d. melanogaster (0.07 vs. 0.16). no variation was detected by two-dimensional electrophoresis of 19 lines scored for 70 abundant proteins. this is consistent with reported reductions in estimates of genic heterozygosity by two-dimensional electrophoresis ... | 1982 | 7095420 |
| artificial selection for altered male wing display in drosophila simulans. | 1982 | 7138454 | |
| crossing-over in the female hybrids between drosophila simulans and drosophila mauritiana. | the cross between d. simulans and d. mauritiana yields fertile hybrid females. crossing-over occurs in such female hybrids. this system allows the transfer of pieces of chromosomes from one species into another, thus providing an experimental tool to analyze the genetic basis of evolutionary problems, as well as the regulation of gene expression during development. | 1982 | 7200915 |
| genetic variability at the esterase-6 locus in natural populations of drosophila simulans in relation to environmental heterogeneity. | the allozymic variation at at the esterase-6 locus examined in fourteen samples of natural populations of drosophila simulans collected in two different localities. the samples were collected from different species of fruits in the two localities and from banana baits located some meters apart from the fruits. the analysis was done by sequential electrophoresis, using varied gel concentrations and buffers. by this technique, we detected 27 alleles at the esterase-6 locus, where only five alleles ... | 1981 | 7327390 |
| the satellite dnas of drosophila simulans. | 1981 | 7333458 | |
| ultrastructural studies on spermatogenesis in a sex-ratio-mutant strain of drosophila simulans. | the aberrant sex-ratio mutation in d. simulans used for this study is a temperature-sensitive autosomal recessive. homozygous males raised at 16 degrees c produce about 2% of f1, but those raised at 26 degrees c, have a normal sex ratio. ultrastructural studies of spermatogenesis have revealed many anomalies in the germ cells of flies raised at 16 degrees c, but the same flies raised at 26 degrees c had few anomalies. the earliest spermatogenic stage with noticeable abnormalities was the primary ... | 1980 | 7405869 |
| cytoplasmic incompatibility in drosophila simulans: dynamics and parameter estimates from natural populations. | in drosophila simulans, cytoplasmically transmitted wolbachia microbes cause reduced egg hatch when infected males mate with uninfected females. a wolbachia infection and an associated mtdna variant have spread northward through california since 1986. pcr assays show that wolbachia infection is prevalent throughout the continental us and central and south america, but some lines from florida and ecuador that are pcr-positive for wolbachia do not cause incompatibility. we estimate from natural po ... | 1995 | 7498773 |
| somatic movement of the mariner transposable element and lifespan of drosophila species. | the effect of somatic movement of the mariner transposable element on lifespan was measured in drosophila simulans and drosophila melanogaster males at 25 degrees c. in d. simulans this movement significantly decreased lifespan, whereas in d. melanogaster no correlation between transposon movement and lifespan was found. the results in d. simulans support the hypothesis that somatic genetic damage induced by dna element movement can reduce lifespan. | 1995 | 7565881 |
| localization of pheromonal sexual dimorphism in drosophila melanogaster and its effect on sexual isolation. | drosophila melanogaster is sexually dimorphic for cuticular hydrocarbons, with males and females having strikingly different profiles of the long-chain compounds that act as contact pheromones. gas-chromatographic analysis of sexual mosaics reveals that the sex specificity of hydrocarbons is located in the abdomen. this explains previous observations that d. melanogaster males display the strongest courtship toward mosaics with female abdomens. we also show that males of the sibling species dros ... | 1995 | 7568163 |
| malathion resistance levels in sympatric populations of drosophila simulans (diptera: drosophilidae) and d. melanogaster differ by two orders of magnitude. | malathion resistance levels were determined in populations of the sympatric species drosophila melanogaster (meigen) and drosophila simulans (sturtevant) from a collection site in tampa bay, fl, with a 20+ yr history of intensive malathion exposure. bioassays of insecticide resistance were done by using a desiccation technique that reduces both the effects of avoidance behavior on the results and the total time of the assay. resistance levels in isofemale lines of d. simulans are as much as 2 or ... | 1995 | 7593892 |
| evolution of single and double wolbachia symbioses during speciation in the drosophila simulans complex. | maternally inherited bacteria of the genus wolbachia are responsible for the early death of embryos in crosses between uninfected females and infected males in several insect species. this phenomenon, known as cytoplasmic incompatibility, also occurs between strains infected by different symbionts in some species, including drosophila simulans. wolbachia was found in two species closely related to d. simulans, drosophila mauritiana, and drosophila sechellia, and shown to cause incompatibility in ... | 1995 | 7604001 |
| genetic studies on premating isolation in drosophila simulans. i.ad. simulans line highly crossable with d. melanogaster. | the s2 line of drosophila simulans, an isofemale line from a natural population at mishima, japan, was found to have high crossability with d. melanogaster. over 80% of the s2 females mated with d. melanogaster males, while only 2.4- 14.2% of control females from other d. simulans lines mated. the reciprocal mating (d. melanogaster female x s2 males) was in normal range (35-50%). the crossability of the f1 females between the s2 and other normal simulans lines was slightly higher than the contro ... | 1995 | 7632441 |
| cloning and characterization of an ftsz homologue from a bacterial symbiont of drosophila melanogaster. | a 1194 bp open reading frame that codes for a 398 amino acid peptide was cloned from a lambda gt11 library of drosophila melanogaster genomic dna. the predicted peptide sequence is very similar to three previously characterized protein sequences that are encoded by the ftsz genes in escherichia coli, bacillus subtilis and rhizobium meliloti. the ftsz protein has a major role in the initiation of cell division in prokaryotic cells. using a tetracycline treatment that eradicates bacterial parasite ... | 1993 | 7689140 |
| the reproductive incompatibility system in drosophila simulans: dapi-staining analysis of the wolbachia symbionts in sperm cysts. | any hitherto available technique used to detect the presence of wolbachia, a rickettsia-like endosymbiont of drosophila simulans, i.e., crossing with tester strains, electron microscope observations, dapi-staining of embryo, or amplification of specific sequences by pcr are notably time-consuming techniques. staining sperm cysts with the fluorochrome dapi is here shown to be a fast and reliable technique to detect the symbiont and evaluate the level of infection of individual males. wolbachia ce ... | 1993 | 7689622 |
| evidence for a wolbachia symbiont in drosophila melanogaster. | the bacterial cell division gene, ftsz, was used as a specific probe to show the presence of a symbiotic bacterium in two wild type strains of drosophila melanogaster. under stringent hybridization conditions we have shown that the bacterium is transferred to the progeny of these strains from infected mothers and can be eradicated by treatment with the antibiotic tetracycline. we have characterized this bacterium, by amplifying and sequencing its 16s rrna gene, as being a member of the genus wol ... | 1993 | 7691685 |
| inferring weak selection from patterns of polymorphism and divergence at "silent" sites in drosophila dna. | patterns of codon usage and "silent" dna divergence suggest that natural selection discriminates among synonymous codons in drosophila. "preferred" codons are consistently found in higher frequencies within their synonymous families in drosophila melanogaster genes. this suggests a simple model of silent dna evolution where natural selection favors mutations from unpreferred to preferred codons (preferred changes). changes in the opposite direction, from preferred to unpreferred synonymous codon ... | 1995 | 7713409 |
| mating propensity of indian drosophila melanogaster populations with d. simulans: a nonadaptive latitudinal cline. | crosses were investigated between a single strain of drosophila simulans and 28 natural indian populations of d. melanogaster. in each case, a mass culture and 10 isofemale lines of d. melanogaster were studied. crosses were much easier between d. melanogaster females and d. simulans males than in the reciprocal case. also, hybrid offspring were easier to obtain by using d. melanogaster flies (either males or females) from isofemale lines than from mass cultures. finally, the crossability, estim ... | 1995 | 7759292 |
| the doc transposable element in drosophila melanogaster and drosophila simulans: genomic distribution and transcription. | the mobile element doc is similar in structure and coding potential to the line families found in various organisms. in this paper, we analyze the insertional and structural polymorphism of this element and show that it appears to have a long evolutionary history in the genome of d. melanogaster. like the family of i elements, the doc family seems to display three types of elements: full length elements, defective members that have recently transposed and long since immobilized members common to ... | 1994 | 7813908 |
| meiosis in drosophila males. i. the question of separate conjunctive mechanisms for the xy and autosomal bivalents. | the conjunctive mechanism of the xy bivalent is believed to differ from that of the autosomal bivalents in the achiasmate drosophila melanogaster male. it has been proposed that hypothetical cohesive elements, termed collochores, hold the x and y chromosomes together at or near their nucleolar organizing regions (nors) and that collochores are not exhibited by autosomal bivalents. in electron micrographs, unique fibrillar material is observed between the x and y chromosomes at the synaptic site. ... | 1994 | 7821091 |
| genetics of hybrid male sterility between drosophila sibling species: a complex web of epistasis is revealed in interspecific studies. | to study the genetic differences responsible for the sterility of their male hybrids, we introgressed small segments of an x chromosome from drosophila simulans into a pure drosophila mauritiana genetic background, then assessed the fertility of males carrying heterospecific introgressions of varying size. although this analysis examined less than 20% of the x chromosome (roughly 5% of the euchromatic portion of the d. simulans genome), and the segments were introgressed in only one direction, a ... | 1994 | 7828817 |
| molecular polymorphism in the period gene of drosophila simulans. | the threonine-glycine (thr-gly) repeat region of the period (per) gene of eight natural populations of drosophila simulans from europe and north africa was analyzed by polymerase chain reaction, dna sequencing and heteroduplex formation. five different length alleles encoding 21, 23, 25 and two different kinds of 24 thr-gly pairs in the uninterrupted repeat were found. in the 3' region flanking the repeat 6 nucleotide substitutions (3 synonymous, 3 replacement) were observed in three different c ... | 1994 | 7851767 |
| neutral and non-neutral evolution of drosophila mitochondrial dna. | to test hypotheses of neutral evolution of mitochondrial dna (mtdna), nucleotide sequences were determined for 1515 base pairs of the nadh dehydrogenase subunit 5 (nd5) gene in the mitochondrial dna of 29 lines of drosophila melanogaster and 9 lines of its sibling species drosophila simulans. in contrast to the patterns for nuclear genes, where d. melanogaster generally exhibits much less nucleotide polymorphism, the number of segregating sites was slightly higher in a global sample of nine nd5 ... | 1994 | 7851771 |
| unraveling selection in the mitochondrial genome of drosophila. | we examine mitochondrial dna variation at the cytochrome b locus within and between three species of drosophila to determine whether patterns of variation conform to the predictions of neutral molecular evolution. the entire 1137-bp cytochrome b locus was sequenced in 16 lines of drosophila melanogaster, 18 lines of drosophila simulans and 13 lines of drosophila yakuba. patterns of variation depart from neutrality by several test criteria. analysis of the evolutionary clock hypothesis shows uneq ... | 1994 | 7851772 |
| nucleotide variation at the hypervariable esterase 6 isozyme locus of drosophila simulans. | esterase 6 (est-6/est6) is polymorphic in both drosophila melanogaster and d. simulans for two common allozyme forms, as well as for several other less common variants. parallel latitudinal clines in the frequencies of the common est6-f and est6-s allozymes in these species have previously been interpreted in terms of a shared amino acid polymorphism that distinguishes the two variants and is subject to selection. here we compare the sequences of four d. simulans est-6 isolates and show that ove ... | 1995 | 7877486 |
| a prokaryotic dnaa sequence in drosophila melanogaster: wolbachia infection and cytoplasmic incompatibility among laboratory strains. | using oligonucleotide primers derived from the aligned polypeptide sequences of several prokaryotic dnaa genes, we amplified from drosophila melanogaster dna a 557 bp fragment containing a single open reading frame. the predicted peptide sequence shows a significant similarity to previously characterized protein sequences that are encoded by the dnaa genes of several prokaryotes. the dnaa sequences are also detectable by pcr in dna from drosophila simulans and nasonia vitripennis flies which are ... | 1994 | 7894745 |
| replacement of the natural wolbachia symbiont of drosophila simulans with a mosquito counterpart. | inherited rickettsial symbionts of the genus wolbachia occur commonly in arthropods and have been implicated in the expression of parthenogenesis, feminization and cytoplasmic incompatibility wolbachia from the asian tiger mosquito, aedes albopictus, to replace the natural infection of drosophila simulans by means of embryonic microinjection techniques. the transferred wolbachia infection behaves like a natural drosophila infection with regard to its inheritance, cytoskeleton interactions and ab ... | 1994 | 7906391 |
| molecular evolution of the metallothionein gene mtn in the melanogaster species group: results from drosophila ananassae. | three distinctly different alleles of the metallothionein gene mtn have been identified in natural drosophila melanogaster populations: mtn.3, mtn1, and dp(mtn1), where the latter designates a tandem duplication of mtn1. in drosophila simulans, only mtn.3-type alleles have been found. it has been suggested that mtn.3 is the ancestral allele and demonstrated that a presumed two-step transition from mtn.3 to mtn1 to dp(mtn1) is accompanied by an approximate 5-fold increase in rna levels. we analyz ... | 1994 | 8001781 |
| cytoplasmic incompatibility in australian populations of drosophila melanogaster. | in drosophila melanogaster, weak incompatibility in crosses between infected and uninfected strains is associated with a wolbachia microorganism. crosses between infected males and uninfected females show a reduction (15-30%) in egg hatch. progeny tests indicated that the infection is widespread in australian d. melanogaster populations and that populations are polymorphic for the presence of the infection. the infection status of 266 lines from 12 populations along the eastern coast of australi ... | 1994 | 8005448 |
| effects of the fourth chromosome on the sterility of hybrids between drosophila simulans and its relatives. | genetic analysis of the fourth chromosome of drosophila simulans shows that it has no effect on either male or female fertility in hybrids with two sibling species, d. mauritiana and d. sechellia. the lack of effect holds even when the d. simulans chromosome is homozygous in a foreign genetic background. the absence of major fourth chromosome "sterility genes" in these hybridizations contrasts with the presence of a fourth-chromosome gene causing complete male sterility in hybrids of the more di ... | 2007 | 8014464 |
| genetics of reproductive isolation in the drosophila simulans clade: complex epistasis underlying hybrid male sterility. | we have analyzed the sterility associated with introgressions of the distal one-fourth of the x chromosome from either drosophila mauritiana or drosophila sechellia into the genome of drosophila simulans using a series of visible and dna markers. because in drosophila hybrids, male sterility is usually complete and is often tightly linked with each of several markers used in crosses, a simple genetic basis has generally been assumed. in our low resolution mapping experiment, we were not able to ... | 1994 | 8056308 |
| evidence for complex genic interactions between conspecific chromosomes underlying hybrid female sterility in the drosophila simulans clade. | f1 hybrid females between the sibling species drosophila simulans, drosophila mauritiana and drosophila sechellia are completely fertile. however, we have found that female sterility can be observed in f2 backcross females who are homozygous for d. simulans x chromosomes and homozygous for autosomal regions from either d. mauritiana or d. sechellia. our results indicate that neither d. mauritiana autosome (2 or 3) can cause complete female sterility in a d. simulans background. the simultaneous ... | 1994 | 8056310 |
| nuclear background affects frequency dynamics of mitochondrial dna variants in drosophila simulans. | transplasmic lines, in which the original mitochondrial dna (mtdna) had been completely replaced by the mtdna of the donor, were constructed to test for selection on mtdna variants and to investigate the effects of nuclear-cytoplasmic interactions in drosophila simulans. these lines were used to set up 12 experimental populations putting in competition two mtdna variants with two different starting frequencies. population cages were maintained for 20 generations and periodically sampled to monit ... | 1994 | 8056616 |
| genetic and maternal variation for heat resistance in drosophila from the field. | in drosophila, field heritability estimates have focused on morphological traits and ignored maternal effects. this study considers heritable variation and maternal effects in a physiological trait, heat resistance. drosophila were collected from the field in melbourne, australia. resistance was determined using knock-down time at 37 degrees. drosophila melanogaster was more resistant than drosophila simulans, and males tended to be more resistant than females. field heritability and maternal ef ... | 1994 | 8088524 |
| lack of correlation between interspecific divergence and intraspecific polymorphism at the suppressor of forked region in drosophila melanogaster and drosophila simulans. | levels of dna sequence polymorphism at the suppressor of forked [su(f)] region in natural populations of drosophila melanogaster and drosophila simulans are estimated by restriction map analysis. su(f) is located at the base of the euchromatic portion of the x chromosome where the level of crossing-over per physical length is extremely low. in a survey of 55 alleles from three natural populations of d. melanogaster, only 2 restriction sites of 27 hexanucleotide and 108 tetranucleotide restrictio ... | 1993 | 8095333 |
| a single-amino acid substitution in a gamma-aminobutyric acid subtype a receptor locus is associated with cyclodiene insecticide resistance in drosophila populations. | resistance to cyclodiene insecticides, documented in at least 277 species, is perhaps the most common kind of resistance to any pesticide. by using cyclodiene resistance to localize the responsible gene, a gamma-aminobutyric acid type a receptor/chloride ion-channel gene was previously cloned and sequenced from an insecticide-susceptible drosophila melanogaster strain. we now describe the molecular genetics of the resistance allele. a single-base-pair mutation, causing a single-amino acid substi ... | 1993 | 8095336 |
| evolutionary inferences from dna variation at the 6-phosphogluconate dehydrogenase locus in natural populations of drosophila: selection and geographic differentiation. | several allozyme-coding genes in drosophila melanogaster show patterns suggesting that polymorphisms at these loci are targets of balancing selection. an important question is whether these genes have similar distributions of underlying dna sequence variation which would indicate similar evolutionary processes occurring in this class of loci. one such locus, 6-phosphogluconate dehydrogenase (pgd), has previously been shown to exhibit clinal variation for fast/slow electromorph variation in the u ... | 1994 | 8138153 |
| analysis of drosophila chromosome 4 using pulsed field gel electrophoresis. | previous estimates of the size of drosophila melanogaster chromosome 4 have indicated that it is 1% to 4% of the genome or approximately 6 mb. we have used pulsed field gel electrophoresis (pfge) to separate megabase-sized molecules of d. melanogaster chromosomal dna. southern blots of these gels were probed with dna fragments from the cubitus interruptus and zfh-2 genes, which are located on chromosome 4. they each identify the same-sized distinct band that migrates at approximately 5.2 mb in d ... | 1993 | 8149812 |
| properties of drosophila simulans strains experimentally infected by different clones of the bacterium wolbachia. | maternally inherited bacteria of the genus wolbachia are responsible for reproductive incompatibilities between strains of drosophila simulans. such incompatibilities are known in several types of crosses, including both directions of crossing between two types of infected strains, 'r' and 's'. to determine whether the bidirectional incompatibility between r and s flies is due only to differences between their bacteria, flies from an uninfected strain have been experimentally infected with bacte ... | 1994 | 8200813 |
| differences in p element population dynamics between the sibling species drosophila melanogaster and drosophila simulans. | patterns of p element establishment and evolution were compared in populations of d. melanogaster and d. simulans. for each species, mixed populations were initiated with m strain flies lacking p elements together with p strain flies having similar p element copy numbers and phenotypes. the mixed populations were subsequently maintained under similar environmental conditions. on the basis of gonadal sterility assays, p elements tended to be significantly more active in d. melanogaster than in d. ... | 1994 | 8206365 |
| a combined classical genetic and high resolution two-dimensional electrophoretic approach to the assessment of the number of genes affecting hybrid male sterility in drosophila simulans and drosophila sechellia. | we have attempted to estimate the number of genes involved in postzygotic reproductive isolation between two closely related species, drosophila simulans and drosophila sechellia, by a novel approach that involves the use of high resolution two-dimensional gel electrophoresis (2de) to examine testis proteins in parents, hybrids and fertile and sterile backcross progenies. the important results that have emerged from this study are as follows: (1) about 8% of about 1000 proteins examined showed d ... | 1993 | 8224814 |
| the effects of interspecific y chromosome replacements on hybrid sterility within the drosophila simulans clade. | we attempted to introgress y chromosomes between three sibling species of drosophila: d. simulans, d. sechellia and d. mauritiana. four d. sechellia y chromosomes were introgressed into d. simulans without loss of fertility whereas the four reciprocal introgressions (d. simulans y introgressed into d sechellia) all result in sterility. both reciprocal y introgressions of d. simulans and d. mauritiana (four of each) also result in sterility. compared with d. simulans males, the males with the d. ... | 1993 | 8244006 |
| evidence for adaptive evolution of the g6pd gene in the drosophila melanogaster and drosophila simulans lineages. | proponents of the neutral theory argue that evolution at the molecular level largely reflects a process of random genetic drift of neutral mutations. under this theory, levels of interspecific divergence and intraspecific polymorphism are expected to be correlated across classes of nucleotide or amino acid sequences with different degrees of functional constraint, such as synonymous and replacement sites. nucleotide sites with reduced polymorphism should show comparably reduced levels of intersp ... | 1993 | 8356041 |
| regulatory aspects of esterase 6 activity variation in sibling drosophila species. | esterase 6 in drosophila melanogaster, drosophila simulans and drosophila mauritiana is produced in several life stages and diverse tissues, but the major pulse of expression is in the sperm ejaculatory duct of adult males. comparison of est6 activity levels among several lines of d. melanogaster, d. simulans and d. mauritiana reveals two major quantitative differences among the species. first, newly eclosed females of both d. simulans and d. mauritiana show significantly higher est6 activity th ... | 1993 | 8360077 |
| noninvolvement of the long terminal repeat of transposable element 17.6 in insecticide resistance in drosophila. | waters and colleagues recently suggested [waters, l. c., zelhof, a. c., shaw, b. j. & ch'ang, l.-y. (1992) proc. natl. acad. sci. usa 89, 4855-4859] that an insertion of a long terminal repeat of transposable element 17.6 into the 3' untranslated region of a p450 gene leads to susceptibility to the insecticide ddt in drosophila melanogaster. we tested this hypothesis by screening lines from around the world and found that the presence or absence of a long terminal repeat was uncorrelated with re ... | 1993 | 8390673 |
| hybrid lethal systems in the drosophila melanogaster species complex. i. the maternal hybrid rescue (mhr) gene of drosophila simulans. | hybrid females from drosophila simulans females x drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as late larvae. the other two classes are sterile adults. letting c, x, and y designate egg cytoplasm, x, and y chromosomes, respectively, and subscripts m and s stand for melanogaster and simulans, cmxmys males are lethal in the larval stage and are rescued by the previously reported genes, lhr (lethal hybrid rescue) in simulans or hmr (hybrid male resc ... | 1993 | 8436276 |
| hybrid lethal systems in the drosophila melanogaster species complex. ii. the zygotic hybrid rescue (zhr) gene of d. melanogaster. | hybrid females from drosophila simulans females x drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as larvae. we have recovered a mutation in melanogaster that rescues the former hybrid females. it was located on the x chromosome at a position close to the centromere, and it was a zygotically acting gene, in contrast with mhr (maternal hybrid rescue) in simulans that rescues the same hybrids maternally. we named it zhr (zygotic hybrid rescue). the gen ... | 1993 | 8436277 |
| dna sequence variation at the period locus within and among species of the drosophila melanogaster complex. | a 1.9-kilobase region of the period locus was sequenced in six individuals of drosophila melanogaster and from six individuals of each of three sibling species: drosophila simulans, drosophila sechellia and drosophila mauritiana. extensive genealogical analysis of 174 polymorphic sites reveals a complex history. it appears that d. simulans, as a large population still segregating very old lineages, gave rise to the island species d. mauritiana and d. sechellia. rather than considering these spec ... | 1993 | 8436278 |
| genetic control of pheromones in drosophila simulans. ii. kété, a locus on the x chromosome. | the production of drosophila cuticular hydrocarbons, including contact pheromones, is under polygenic control. to investigate x-linked loci, ems mutations were induced in drosophila simulans flies. a mutant strain was discovered which in both sexes show a reduction in the biosynthesis of both 7-tricosene (7-t) the species contact pheromone and all other linear hydrocarbons. the locus controlling this effect, kété, is recessive and was localized to i, 18.5. unlike a previously identified gene on ... | 1993 | 8454203 |
| interspecific and intraspecific horizontal transfer of wolbachia in drosophila. | cytoplasmic incompatibility (ci) in drosophila simulans is related to infection of the germ line by a rickettsial endosymbiont (genus wolbachia). wolbachia were transferred by microinjection of egg cytoplasm into uninfected eggs of both d. simulans and d. melanogaster to generate infected populations. transinfected strains of d. melanogaster with lower densities of wolbachia than the naturally infected d. simulans strain did not express high levels of ci. however, transinfected d. melanogaster e ... | 1993 | 8511587 |
| the genetic basis of haldane's rule and the nature of asymmetric hybrid male sterility among drosophila simulans, drosophila mauritiana and drosophila sechellia. | haldane's rule (i.e., the preferential hybrid sterility and inviability of heterogametic sex) has been known for 70 years, but its genetic basis, which is crucial to the understanding of the process of species formation, remains unclear. in the present study, we have investigated the genetic basis of hybrid male sterility using drosophila simulans, drosophila mauritiana and drosophila sechellia. an introgression of d. sechellia y chromosome into a fairly homogenous background of d. simulans did ... | 1993 | 8514134 |
| genetics of reproductive isolation in the drosophila simulans clade: dna marker-assisted mapping and characterization of a hybrid-male sterility gene, odysseus (ods). | in this study, we address the question of whether there exist major genes that cause complete male sterility in the interspecific hybrids of drosophila and, if they do, how these genes may be characterized at the molecular level. our approach is to introgress small segments of the x chromosome from drosophila mauritiana (or drosophila sechellia) into drosophila simulans by repeated backcrosses for more than 20 generations. the introgressions are monitored by both visible mutations and a series o ... | 1993 | 8514135 |
| the distribution of transposable elements on x chromosomes from a natural population of drosophila simulans. | the distribution of 13 transposable element families along 15 x chromosomes from an african natural population of drosophila simulans was determined by in situ hybridization to polytene chromosomes. the transposable elements cloned from drosophila melanogaster all hybridized with drosophila simulans chromosomes. the number of copies per family was 3.5 times lower in the latter species and correlated with the copy number per family in drosophila melanogaster. with the exception of 297, the copy n ... | 1995 | 8522157 |
| the distribution of the transposable element bari-1 in the drosophila melanogaster and drosophila simulans genomes. | the distribution of the transposable element bari-1 in d. melanogaster and d. simulans was examined by southern blot analysis and by in situ hybridization in a large number of strains of different geographical origins and established at different times. bari-1 copies mostly homogeneous in size and physical map are detected in all strains tested. both in d. melanogaster and in d. simulans a relatively high level of intraspecific insertion site polymorphism is detectable, suggesting that in both s ... | 1995 | 8522166 |
| evolutionary dynamics of the enhancer region of even-skipped in drosophila. | we report findings on naturally occurring variation in the regulatory region of even-skipped in drosophila. this pair-rule gene encodes a homeobox-containing transcription factor, is expressed as a series of seven transverse stripes in developing embryos, and defines parasegmental boundaries. the 5' flanking region of the gene contains a 671-bp enhancer governing stripe 2 expression. the stripe 2 enhancer contains multiple binding sites for four transcription factors that provide positional info ... | 1995 | 8524036 |
| nucleotide polymorphism in the 5' promoter region of esterase 6 in drosophila melanogaster and its relationship to enzyme activity variation. | a 974-bp region immediately 5' of the esterase 6 gene was sequenced in 17 field derived third chromosome isoallelic lines. twenty-three polymorphisms were identified, only two in the first 400 bp 5' but 16 in a 325-bp region from -494 to -819 bp. this distribution differs from previously published patterns in drosophila simulans and d. mauritiana, where the first 800 bp are highly conserved. fourteen common polymorphisms in the 325-bp region above are all in strong linkage disequilibrium with ea ... | 1995 | 8536969 |
| indirect evidence of alteration in the expression of the rdna genes in interspecific hybrids between drosophila melanogaster and drosophila simulans. | crosses between drosophila melanogaster females and d. simulans males produce viable hybrid females, while males are lethal. these males are rescued if they carry the d. simulans lhr gene. this paper reports that females of the wild-type d. melanogaster population staket do not produce viable hybrid males when crossed with d. simulans lhr males, a phenomenon which we designate as the staket phenotype. the agent responsible for this phenomenon was found to be the staket x chromosome (xmel, stk). ... | 1996 | 8569692 |
| naturally-occurring wolbachia infection in drosophila simulans that does not cause cytoplasmic incompatibility. | microbes of the genus wolbachia are transmitted by their hosts via the maternal parent and are responsible for cytoplasmic incompatibility among insect populations. this phenomenon can result in wolbachia spreading through natural populations as previously demonstrated in drosophila simulans. here we describe another wolbachia infection in d. simulans that does not cause cytoplasmic incompatibility. this is a property of the wolbachia rather than the nuclear background. the infection occurs at a ... | 1996 | 8575931 |
| variability within the seychelles cytoplasmic incompatibility system in drosophila simulans. | in drosophila simulans, we described a cytoplasmic incompatibility (ci) system (seychelles) restricted to insular populations that harbor the mitochondrial type sii. since then, these populations have been shown to be heterogeneous, some being infected by one wolbachia genetic variant only (wha), while others are infected simultaneously by wha and by another variant (wno) always found in association with wha. we have experimentally obtained two d. simulans strains only infected by the wno varian ... | 1995 | 8582608 |
| wolbachia superinfections and the expression of cytoplasmic incompatibility. | strains of drosophila simulans from riverside, california (dsr) and hawaii (dsh) harbour distinct strains of the cytoplasmic incompatibility microorganism wolbachia, resulting in the expression of bidirectional incompatibility when crossed. d. simulans lines carrying both of these (superinfected) wolbachia strains were generated by the transfer of infected dsh cytoplasm into dsr embryos by microinjection. the superinfected flies were unidirectionally incompatible with both dsr and dsh individual ... | 1995 | 8587875 |
| haplotype test reveals departure from neutrality in a segment of the white gene of drosophila melanogaster. | restriction map studies previously revealed extensive linkage disequilibria in the transcriptional unit of the white locus in natural drosophila melanogaster populations. to understand the causes of these disequilibria, we sequenced a 4722-bp region of the white gene from 15 lines of d. melanogaster and 1 line of drosophila simulans. statistical tests applied to the entire 4722-bp region do not reject neutrality. in contrast, a test for high-frequency haplotypes ("haplotype test") revealed an 83 ... | 1995 | 8601488 |
| geographical variation in insertion site number of retrotransposon 412 in drosophila simulans. | the insertion site number of the retrotransposable element 412 was analyzed in natural populations of drosophila simulans of worldwide origin by in situ hybridization. we observe a gradient in copy number ranging from as high as 23 in europe to 1-10 in south africa, while populations in madagascar and the indian islands, which are the cradle of d. simulans, have only 3-7 copies. we find very different copy numbers in some local populations of australia and the pacific islands (with around 60 cop ... | 1996 | 8642613 |
| the relationship between structural variation and dysgenic properties of p elements in long-established p-transformed lines of drosophila simulans. | ten lines of drosophila simulans were investigated with respect to p activity, p susceptibility and the number and structure of their p copies, eight years after transformation with the p element. all 10 were found to have reached a steady state. they exhibited varying levels of p activity (from 0 per cent to 96 per cent gd sterility) and, with the exception of one line, were not p-susceptible. in contrast with p element behaviour in d. melanogaster: (i) no relationship was found between the mol ... | 1996 | 8682694 |
| 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 |
| evolutionary changes in the expression pattern of a developmentally essential gene in three drosophila species. | the hypothesis that morphological evolution may largely result from changes in gene regulation rather than gene structure has been difficult to test. morphological differences among insects are often apparent in the cuticle structures produced. the dopa decarboxylase (ddc) and alpha-methyldopa hypersensitive (amd) genes arose from an ancient gene duplication. in drosophila, they have evolved nonoverlapping functions, including the production of distinct types of cuticle, and for ddc, the product ... | 1996 | 8692952 |
| the genetics of reproductive isolation in the drosophila simulans clade: x vs. autosomal effects and male vs. female effects. | a strong effect of homozygous autosomal regions on reproductive isolation was found for crosses between the species in the drosophila simulans clade. second chromosome regions were introgressed from d. mauritiana and d. sechellia into d. simulans and tested for their homozygous effects on hybrid male and hybrid female sterility and inviability. most introgressions are fertile as heterozygotes, yet produce sterile male offspring when made homozygous. the density of homozygous autosomal factors co ... | 1996 | 8807297 |
| cytological analysis of fertilization and early embryonic development in incompatible crosses of drosophila simulans. | cytoplasmic incompatibility (ci) is a unique form of male sterility found in numerous insect species that harbor a bacterial endosymbiont wolbachia. ci is characterized by severe reduction in the progeny produced when infected males are crossed to uninfected females. the reduction in progeny correlates with developmental defects that arise during and immediately following fertilization, suggesting that sperm function is disrupted. to investigate the nature of the cellular defects associated with ... | 1996 | 8817452 |
| genetics of a difference in male cuticular hydrocarbons between two sibling species, drosophila simulans and d. sechellia. | in seven of the eight species of the drosophila melanogaster group, the predominant cuticular hydrocarbon of males is 7-tricosene, but in the island endemic species d. sechellia it is 6-tricosene. the phylogeny of the group implies that the novel hydrocarbon profile of d. sechellia is a derived character. genetic analysis of hybrids between d. sechellia and its close relative d. simulans show that each of the five major chromosome arms carries at least one gene affecting the ratio of the two tri ... | 1996 | 8844156 |
| genetic analysis of a morphological shape difference in the male genitalia of drosophila simulans and d. mauritiana. | two closely related species of drosophila, d. simulans and d. mauritiana, differ markedly in morphology of the posterior lobe of the male genital arch. both size and shape aspects of lobe variation can be quantified by a morphometric descriptor based on elliptical fourier and principal components analyses. the genetic architecture of this quantitative trait (pc1) was investigated by hybridizing inbred lines to produce two backcross populations approximately 200 individuals each, which were analy ... | 1996 | 8846893 |
| a genome-wide survey of hybrid incompatibility factors by the introgression of marked segments of drosophila mauritiana chromosomes into drosophila simulans. | in hybrids between drosophila simulans and d. mauritiana, males are sterile and females are fertile, in compliance with haldane's rule. the genetic basis of this phenomenon was investigated by introgression of segments of the mauritiana genome into a simulans background. a total of 87 positions throughout the mauritiana genome were marked with p-element insertions and replicate introgressions were made by repeated backcrossing to simulans for 15 generations. the fraction of hemizgyous x chromoso ... | 1996 | 8849890 |
| a molecular taxonomy for cricket paralysis virus including two new isolates from australian populations of drosophila (diptera: drosophilidae). | two new isolates of cricket paralysis virus, tar and sim, are described that were originally isolated from laboratory colonies of drosophila melanogaster and drosophila simulans respectively. using a combination of biological, serological and molecular characters it was possible to distinguish the sim isolate from all other isolates and it is thus described as a new strain; crpvsim. the tar isolate however, was indistinguishable from the crpv reference isolate crpvvic/gm/d2(2)/gm/d2(2) (teleogry ... | 1996 | 8856030 |
| high nucleotide sequence variation in a region of low recombination in drosophila simulans is consistent with the background selection model. | we surveyed nucleotide sequence variation at glucose dehydrogenase (gld), in a region of low recombination on chromosome 3r, from a population sample of drosophila simulans. the levels of nucleotide variation were surprisingly high. there was no departure from the expectation of a neutral model for the level of polymorphism, indicating no evidence of a selective sweep in this region. there was a significant deficiency of singleton polymorphisms according to the fu and li test, although tajima an ... | 1996 | 8865667 |
| discord between the phylogenies inferred from molecular versus functional data: uneven rates of functional evolution or low levels of gene flow? | according to measures of molecular divergence, the three species of the drosophila simulans clade are closely related to and essentially equidistant from each other. we introgressed 10% of the d. sechellia x chromosome into a pure d. simulans genetic background and found that males carrying this introgressed region were consistently fertile; in contrast, males carrying the same segment from d. mauritiana are sterile and suffer from incompatibilities at a minimum of four loci. together with other ... | 1996 | 8913771 |
| molecular structure of the transposable element ninja in drosophila simulans. | genetically unstable dna sequences of 16.1 kb in length were isolated from the white locus of the w(mky) strain of drosophila simulans. this insertional dna has some unique characteristics as a transposon. it is found in high numbers in this strain and its revertant strains w(psm1) and w(cho), but not elsewhere, and the sequence is a tandem triplication of a basic repeating unit. in order to determine the structure of the insert as whole and the functional unit as a transposon, we analyzed nine ... | 1996 | 8925473 |
| population genetics of silent and replacement variation in drosophila simulans and d. melanogaster: x/autosome differences? | 1996 | 8952085 | |
| somatic activity of the mariner transposable element in natural populations of drosophila simulans. | the characteristics of the mariner transposable element in natural populations of drosophila simulans from different parts of the world were analysed. the somatic excision rate (estimated from a test-cross with a reference strain), the average number of copies (determined by southern blots), and the presence of deleted copies (detected by polymerase chain reaction amplification) were estimated for each population. there was a great variability in the somatic excision rate, measured as the percen ... | 1996 | 8952091 |
| reduced variation in drosophila simulans mitochondrial dna. | we investigated the evolutionary dynamics of infection of a drosophila simulans population by a maternally inherited insect bacterial parasite, wolbachia, by analyzing nucleotide variability in three regions of the mitochondrial genome in four infected and 35 uninfected lines. mitochondrial variability is significantly reduced compared to a noncoding region of a nuclear-encoded gene in both uninfected and pooled samples of flies, indicating a sweep of genetic variation. the selective sweep of mi ... | 1996 | 8978041 |
| conceptual translation of timeless reveals alternative initiating methionines in drosophila. | we have sequenced genomic fragments which encode the n-terminus of the timeless (tim) clock protein in drosophila simulans and d. yakuba. we observe that in these two species, the initiating methionine appears to lie downstream of the one proposed to encode the translational start ind.melanogaster, thereby truncating the n-terminus by 23 amino acids. we then sequenced the corresponding 5'fragment in a number of d. melanogaster individuals from different strains. we observed a polymorphism which ... | 1997 | 9016581 |
| transposition rate of the 412 retrotransposable element is independent of copy number in natural populations of drosophila simulans. | the transposition and excision rates of the 412 retrotransposable element were estimated in five populations of drosophila simulans differing in their average 412 copy numbers, which ranged from 2 to 54. the transposition rate was found to equal 1 x 10(-3) to 2 x 10(-3), independently of copy number. no excision was detected. these values eliminate autoregulation as a force maintaining copy number of the 412 element in natural populations of d. simulans. | 1997 | 9029796 |