| dosage compensation and dietary glucose repression of larval amylase activity in drosophila miranda. | the functional locus for alpha-amylase (amy) in drosophila miranda is in the evolutionarily new x2 chromosome. x2 evolved from an autosome in response to an ancestral autosome-y translocation that gave rise to the "neo-y" chromosome of this species. y-linked amy, if still present in the ancestrally translocated element, is unexpressed. dosage compensation for amylase activity was examined in larvae of the s 204 strain. since dietary glucose is known to repress amy expression in drosophila melano ... | 1990 | 2085311 |
| genetic variation for dispersal by drosophila pseudoobscura and drosophila persimilis. | release-recapture experiments using drosophila pseudoobscura and d. persimilis strains of different karyotypes were performed in a heterogeneous environment. the heterogeneity was due to both spatial variation and the species of yeast used to attract the released flies. no karyotypic-specific habitat preferences were detected. however, in all releases, different strains did behave differently with respect to one or both of the heterogeneous factors. these results indicate there is variation for ... | 1986 | 17246313 |
| fine-scale mapping of recombination rate in drosophila refines its correlation to diversity and divergence. | regional rates of recombination often correlate with levels of nucleotide diversity, and either selective or neutral hypotheses can explain this relationship. regional recombination rates also correlate with nucleotide differences between human and chimpanzee, consistent with models where recombination is mutagenic; however, a lack of correlation is observed in the drosophila melanogaster group, consistent with models invoking natural selection. here, we revisit the relationship among recombinat ... | 2008 | 18621713 |
| genetic and evolutionary correlates of fine-scale recombination rate variation in drosophila persimilis. | recombination is fundamental to meiosis in many species and generates variation on which natural selection can act, yet fine-scale linkage maps are cumbersome to construct. we generated a fine-scale map of recombination rates across two major chromosomes in drosophila persimilis using 181 snp markers spanning two of five major chromosome arms. using this map, we report significant fine-scale heterogeneity of local recombination rates. however, we also observed "recombinational neighborhoods," wh ... | 2010 | 20890595 |
| genetics of male and female sterility in hybrids of drosophila pseudoobscura and d. persimilis. | the genetic basis of male and female sterility in hybrids of drosophila pseudoobscura-drosophila persimilis was studied using backcross analysis. previous studies indirectly assessed male fertility by measuring testis size; these studies concluded that male sterility results from an x chromosome-autosome imbalance. by directly scoring for the production of motile sperm, male sterility is shown to be largely due to an incompatibility between genes on the x and y chromosomes of these two species. ... | 2013 | 3623079 |
| epistasis modifies the dominance of loci causing hybrid male sterility in the drosophila pseudoobscura species group. | speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. postzygotic barriers to gene flow, such as f(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. f(1) hybrid incompatibilities in taxa that obey haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from i ... | 2009 | 19686263 |
| 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 |
| faster-x effects in two drosophila lineages. | under certain circumstances, x-linked loci are expected to experience more adaptive substitutions than similar autosomal loci. to look for evidence of faster-x evolution, we analyzed the evolutionary rates of coding sequences in two sets of drosophila species, the melanogaster and pseudoobscura clades, using whole-genome sequences. one of these, the pseudoobscura clade, contains a centric fusion between the ancestral x chromosome and the autosomal arm homologous to 3l in d. melanogaster. this of ... | 2014 | 25323954 |
| chromosomal localization and partial sequencing of the 18s and 28s ribosomal genes from bradysia hygida (diptera: sciaridae). | in insects, ribosomal genes are usually detected in sex chromosomes, but have also or only been detected in autosomal chromosomes in some cases. previous results from our research group indicated that in bradysia hygida, nucleolus organizer regions were associated with heterochromatic regions of the autosomal c chromosome, using the silver impregnation technique. the present study confirmed this location of the ribosomal genes using fluorescence in situ hybridization analysis. this analysis also ... | 2014 | 24737466 |
| remating responses are consistent with male postcopulatory manipulation but not reinforcement in d. pseudoobscura. | reinforcement occurs when hybridization between closely related lineages produces low-fitness offspring, prompting selection for elevated reproductive isolation specifically in areas of sympatry. both premating and postmating prezygotic behaviors have been shown to be the target of reinforcing selection, but it remains unclear whether remating behaviors experience reinforcement, although they can also influence offspring identity and limit formation of hybrids. here, we evaluated evidence for re ... | 2017 | 28116047 |
| temporal stability of molecular diversity measures in natural populations of drosophila pseudoobscura and drosophila persimilis. | many molecular ecological and evolutionary studies sample wild populations at a single point in time, but that data represents genetic variation from a potentially unrepresentative snapshot in time. variation across time in genetic parameters may occur quickly in species that produce multiple generations of offspring per year. here, we compare genetic diversity in wild caught populations of drosophila persimilis and drosophila pseudoobscura collected 16 years apart at the same time of year and s ... | 2017 | 25969560 |
| genomic impacts of chromosomal inversions in parapatric drosophila species. | chromosomal inversions impact genetic variation and facilitate speciation in part by reducing recombination in heterokaryotypes. we generated multiple whole-genome shotgun sequences of the parapatric species pair drosophila pseudoobscura and drosophila persimilis and their sympatric outgroup (drosophila miranda) and compared the average pairwise differences for neutral sites within, just outside and far outside of the three large inversions. divergence between d. pseudoobscura and d. persimilis ... | 2012 | 22201171 |
| effects of inversions on within- and between-species recombination and divergence. | chromosomal inversions disrupt recombination in heterozygotes by both reducing crossing-over within inverted regions and increasing it elsewhere in the genome. the reduction of recombination in inverted regions facilitates the maintenance of hybridizing species, as outlined by various models of chromosomal speciation. we present a comprehensive comparison of the effects of inversions on recombination rates and on nucleotide divergence. within an inversion differentiating drosophila pseudoobscura ... | 2011 | 21828374 |
| genetics of hybrid male sterility among strains and species in the drosophila pseudoobscura species group. | taxa in the early stages of speciation may bear intraspecific allelic variation at loci conferring barrier traits in hybrids such as hybrid sterility. additionally, hybridization may spread alleles that confer barrier traits to other taxa. historically, few studies examine within- and between-species variation at loci conferring reproductive isolation. here, we test for allelic variation within drosophila persimilis and within the bogota subspecies of d. pseudoobscura at regions previously shown ... | 2011 | 21729052 |
| evolution of sex chromosomes: dosage compensation of the lcp1-4 gene cluster on the evolving neo-x chromosome in drosophila miranda. | in drosophila miranda the small multigene family of the larval cuticle protein (lcp1-4) genes resides on the evolving neo-x and neo-y sex chromosome pair while in the sibling species drosophila pseudoobscura and drosophila persimilis the gene cluster is inherited autosomally. the neo-y chromosomal lcp1, lcp2 and lcp4 genes are, as previously shown by us, not expressed and only lcp3 is expressed at a strongly reduced level. as a first step in understanding the evolutionary mechanism(s) transformi ... | 2007 | 17352708 |
| postmating-prezygotic isolation is not an important source of selection for reinforcement within and between species in drosophila pseudoobscura and d. persimilis. | most work on adaptive speciation to date has focused on the role of low hybrid fitness as the force driving reinforcement (the evolution of premating isolation after secondary contact that reduces the likelihood of matings between populations). however, recent theoretical work has shown that postmating, prezygotic incompatibilities may also be important in driving premating isolation. we quantified premating, postmating-prezygotic, and early postzygotic fitness effects in crosses among three pop ... | 2005 | 16136803 |
| unusual pattern of single nucleotide polymorphism at the exuperantia2 locus of drosophila pseudoobscura. | we have investigated the pattern of dna sequence variation at the exuperantia2 locus in drosophila pseudoobscura. this adds to the increasing dataset of genetic variation in d. pseudoobscura, a useful model species for evolutionary genetic studies. the level of silent site nucleotide diversity and the divergence from an outgroup drosophila miranda are comparable with those for other x-linked loci. one peculiar pattern at the exu2 locus of d. pseudoobscura is a complete linkage disequilibrium bet ... | 2003 | 14768894 |
| chromosomal inversions and the reproductive isolation of species. | recent genetic studies have suggested that many genes contribute to differences between closely related species that prevent gene exchange, particularly hybrid male sterility and female species preferences. we have examined the genetic basis of hybrid sterility and female species preferences in drosophila pseudoobscura and drosophila persimilis, two occasionally hybridizing north american species. contrary to findings in other species groups, very few regions of the genome were associated with t ... | 2001 | 11593019 |
| a biogeographic genetic approach for testing the role of reinforcement: the case of drosophila pseudoobscura and d. persimilis. | the role of reinforcement in speciation can be explained by two distinct models. in model i, two diverged populations hybridize and produce fertile hybrids that successfully backcross (hybridization with gene flow). in model ii, two populations hybridize but succeeding backcrosses are unproductive (hybridization without gene flow). using drosophila persimilis and d. pseudoobscura, we have tested model i by comparing the extent of heterospecific introgression in sympatric versus allopatric popula ... | 2000 | 10937197 |
| microsatellite variation in populations of drosophila pseudoobscura and drosophila persimilis. | we have isolated, characterized and mapped 33 dinucleotide, three trinucleotide and one tetranucleotide repeat loci from the four major chromosomes of drosophila pseudoobscura. average inferred repeat unit length of the dinucleotide repeats is 12 repeat units, similar to d. melanogaster. assays of d. pseudoobscura and populations of its sibling species, d. persimilis, using 10 of these loci show extremely high levels of variation compared with similar studies of dinucleotide repeat variation in ... | 2000 | 10740918 |
| molecular evolution of the sex-ratio inversion complex in drosophila pseudoobscura: analysis of the esterase-5 gene region. | the sex-ratio chromosome in drosophila pseudoobscura is subject to meiotic drive. it is associated with a series of three nonoverlapping paracentric inversions on the right arm of the x chromosome. the esterase-5 gene region has been localized to section 23 within the subbasal inversion of the sex-ratio inversion complex, making esterase-5 a convenient locus for molecular evolutionary analyses of the sex-ratio inversion complex and the associated drive system. a 504-bp fragment of noncoding, int ... | 1996 | 8587496 |
| molecular evolution of inversions in drosophila pseudoobscura: the amylase gene region. | the amylase region of the third chromosome of drosophila pseudoobscura has been cloned and localized to cytological band 73a. it is contained within a series of highly polymorphic inversions and serves as a convenient tool for a molecular evolutionary analysis of the inverted gene arrangements. amylase in d. pseudoobscura is a family of three genes, and some chromosomes have deletions for one or two of them. two overlapping clones covering 26 kilobases were isolated and used as probes to survey ... | 1991 | 1702542 |
| natural selection vs. random drift: evidence from temporal variation in allele frequencies in nature. | we have obtained monthly samples of two species, drosophila pseudoobscura and drosophila persimilis, in a natural population from napa county, california. in each species, about 300 genes have been assayed by electrophoresis for each of seven enzyme loci in each monthly sample from march 1972 to june 1975. using statistical methods developed for the purpose, we have examined whether the allele frequencies at different loci vary in a correlated fashion. the methods used do not detect natural sele ... | 1985 | 4054608 |
| evidence for extensive genetic differentiation between the sex-ratio and the standard arrangement of drosophila pseudoobscura and d. persimilis and identification of hybrid sterility factors. | this study deals with sex-ratio genes tightly linked within the sex-ratio inversion. by taking advantage of the fact that the sex-ratio chromosome of drosophila persimilis [sr(b)] is homosequential to the standard chromosome of d. pseudoobscura [st(a)], we carried out two reciprocal introgression experiments. individual segments of sr(b) or st(a) were introgressed into the genome of d. pseudoobscura or d. persimilis, respectively. males possessing a hybrid sr(b)-st(a) x chromosome and a genetic ... | 1983 | 17246158 |
| components of maze running in drosophila pseudoobscura dn drosophila persimilis. | | 1981 | 7325947 |
| photobehavioral differentiation in natural populations of drosophila: changes of photoresponse over time in drosophila pseudoobscura and drosophila persimilis. | the photobehavior of a sympatric assemblage of drosophila pseudoobscura and d. persimilis from california was examined over a 13-month period. during that time, certain aspects of the behavior remained constant (e.g., the mean resting photoresponse), while other aspects changed (e.g., the level of genotypic variation of the resting photoresponse of d. persimilis). the data support the contention of rockwell et al. [rockwell, r. f., cooke, f., and harmsen, r. (1975). behav. genet. 5:189-202] that ... | 1980 | 7469972 |
| distinctions among allelic variants associated with chromosome 3 inversions in drosophila pseudoobscura and drosophila persimilis. | efforts were made to discriminate new genetic variants among electrophoretic alleles that are associated with chromosome 3 inversions of drosophila pseudoobscura and d. persimilis. apparent genetic similarities for electrophoretic alleles between these two species and among the common inversions they carry were reexamined by altering gel concentration and buffer ph. at the amylase locus, the 1.09 electrophoretic allele could be further separated into two allelic classes that differentiated the w ... | 1980 | 6167488 |
| an experimental investigation of the unit charge model of protein polymorphism and its relation to the esterase-5 locus of drosophila pseudoobscura, drosophila persimilis, and drosophila miranda. | the relationship between charge changes and electrophoretic mobility changes is investigated experimentally. the charge of several proteins is altered by reaction with small molecules of known structure and the change in electrophoretic mobility is measured. the method of ferguson plots is used to separate charge and shape components of mobility differences. the average effect of an amino acid charge change on the mobility of the esterase-5( 1.00) allele of drosophila pseudoobscura is estimated ... | 1977 | 17248784 |
| genic heterogeneity at two alcohol dehydrogenase loci in drosophila pseudoobscura and drosophila persimilis. | a sequential electrophoretic survey of the second chromosome loci, alcohol dehydrogenase-6 (adh-6) and octanol dehydrogenase ( odh), was performed on 147 isochromosomal lines of drosophila pseudoobscura and 60 lines of its sibling species, d. persimilis. gels run with a variety of acrylamide concentrations and buffer ph's revealed the presence of 18 alleles of adh-6 in the two species, where only eight had been previously detected by conventional electrophoretic methods. only two alleles were ad ... | 1977 | 17248763 |
| gene differences between the sex ratio and standard gene arrangements of the x chromosome in drosophila persimilis. | the sibling species drosophila pseudoobscura and d. persimilis each carry two gene arrangements in the right arm of the x chromosome; standard (st) and sex ratio (sr). the sr sequence of d. persimilis and the st sequence of d. pseudoobscura have the same banding pattern. these cytologically identical arrangements carry different alleles at the esterase-5 (est-5) and phosphoglucomutase-1 ( pgm-1) loci. all the alleles on the sr arrangement of d. persimilis are also present on the st arrangement o ... | 1977 | 17248742 |
| photobehavioral differentiation in natural populations of drosophila pseudoobscura and drosophila persimilis. | the photoresponses of natural populations of d. pseudoobscura and d. persimilis, occurring sympatrically, are measured in two environmental conditions ("at rest" and "disturbed"). comparisons of the responses, intraspecifically and interspecifically, lead to the following conclusions. these must be considered within the confines of the operational nature of the measurement of laboratory photoresponses. (1) within each species population, significant nonenvironmental differentiation has been allo ... | 1975 | 1131147 |
| rates of spontaneous mutation in the second chromosomes of the sibling species, drosophila pseudoobscura and drosophila persimilis. | | 1954 | 17247527 |
| experiments on sexual isolation in drosophila: x. reproductive isolation between drosophila pseudoobscura and drosophila persimilis under natural and under laboratory conditions. | | 1951 | 16589029 |
| morphological differences between two sibling species; drosophila pseudoobscura and drosophila persimilis. | | 1951 | 14808171 |
| effectiveness of intraspecific and interspecific matings in drosophila pseudoobscura and drosophila persimilis. | | 2015 | 20286615 |
| genetics of sexual isolation between drosophila pseudoobscura and drosophila persimilis. | | 1946 | 17247220 |
| experiments on sexual isolation in drosophila: viii. influence of light on the mating behavior of drosophila subobscura, drosophila persimilis and drosophila pseudoobscura. | | 1946 | 16578209 |
| experiments on sexual isolation in drosophila: vii. the nature of the isolating mechanisms between drosophila pseudoobscura and drosophila persimilis. | | 1946 | 16588725 |
| experiments on sexual isolation in drosophila: vi. isolation between drosophila pseudoobscura and drosophila persimilis and their hybrids. | | 1946 | 16578193 |
| experiments on sexual isolation in drosophila: iv. modification of the degree of isolation between drosophila pseudoobscura and drosophila persimilis and sexual preferences in drosophila prosoltans. | | 1945 | 16588688 |
| 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 |
| epistasis among drosophila persimilis factors conferring hybrid male sterility with d. pseudoobscura bogotana. | the bateson-dobzhansky-muller model posits that hybrid incompatibilities result from genetic changes that accumulate during population divergence. indeed, much effort in recent years has been devoted to identifying genes associated with hybrid incompatibilities, often with limited success, suggesting that hybrid sterility and inviability are frequently caused by complex interactions between multiple loci and not by single or a small number of gene pairs. our previous study showed that the nature ... | 2010 | 21060872 |
| genetic divergence in closely related sibling species drosophila pseudoobscura, drosophila persimilis and drosophila miranda. | | 1977 | 28567734 |
| triggers of the postural display of courtship in drosophila persimilis flies. | d. persimilis courtship shows some flexibility and courting males sometimes perform an elaborate postural display in addition to the standard courtship behaviours shared by most drosophila species. this postural display includes the acrobatic contortion and tremulation of their abdomen, accompanied by the generation of substrate-borne vibrations, and they proffer a nutritional droplet to the female. here, we use courtship and choice assays to ask what triggers this display and what advantages ma ... | 2017 | 29104367 |
| reproductive interference by male drosophila subobscura on female d. persimilis: a laboratory experiment. | while females often reject courtship attempts by heterospecific males, reproductive interference by harassment from such males can nonetheless occur, potentially reducing female fitness. such effects may be profound following a range expansion, when males from a new species may suddenly encounter (and perhaps even become abundant relative to) females of related native species. drosophila subobscura recently invaded north america and may impact native species through reproductive interference and ... | 2017 | 28405290 |
| the elaborate postural display of courting drosophila persimilis flies produces substrate-borne vibratory signals. | sexual selection has led to the evolution of extraordinary and elaborate male courtship behaviors across taxa, including mammals and birds, as well as some species of flies. drosophila persimilis flies perform complex courtship behaviors found in most drosophila species, which consist of visual, air-borne, gustatory and olfactory cues. in addition, drosophila persimilis courting males also perform an elaborate postural display that is not found in most other drosophila species. this postural dis ... | 2016 | 27795616 |
| mapping of within-species segregation distortion in drosophila persimilis and hybrid sterility between d. persimilis and d. pseudoobscura. | in contrast to the prevailing dogma in the 1990s, recent studies have suggested that an evolutionary history of segregation distortion within species may contribute to sterility in species hybrids. however, this recent work identified segregation distortion exclusively in species hybrids that may never have had an evolutionary history of segregation distortion in either parent species. we expand on previous work using a strain of drosophila persimilis exhibiting segregation distortion within spe ... | 2012 | 22966762 |
| alignment-free population genomics: an efficient estimator of sequence diversity. | comparative sequencing contributes critically to the functional annotation of genomes. one prerequisite for successful analysis of the increasingly abundant comparative sequencing data is the availability of efficient computational tools. we present here a strategy for comparing unaligned genomes based on a coalescent approach combined with advanced algorithms for indexing sequences. these algorithms are particularly efficient when analyzing large genomes, as their run time ideally grows only li ... | 2012 | 22908037 |
| learning decreases heterospecific courtship and mating in fruit flies. | recent theory and data suggest that adaptive use of learning in the context of sexual behaviour could contribute to assortative mating. experiments examining this issue indicated that male drosophila persimilis that experienced courtship and rejection by heterospecific females exhibited significantly lower levels of heterospecific courtship and mating compared with those of inexperienced males. these results indicate that experience in the context of sexual behaviour in fruit flies could reduce ... | 2008 | 18842572 |
| the genetics of hybrid male sterility between the allopatric species pair drosophila persimilis and d. pseudoobscura bogotana: dominant sterility alleles in collinear autosomal regions. | f(1) hybrid male sterility is thought to result from interactions between loci on the x chromosome and dominant-acting loci on the autosomes. while x-linked loci that contribute to hybrid male sterility have been precisely localized in many animal taxa, their dominant autosomal interactors have been more difficult to localize precisely and/or have been shown to be of relatively smaller effect. here, we identified and mapped at least four dominant autosomal factors contributing to hybrid male ste ... | 2007 | 17277364 |
| genetics of sexual isolation and courtship dysfunction in male hybrids of drosophila pseudoobscura and drosophila persimilis. | despite the importance of sexual isolation to speciation, few studies have analyzed the genetic basis of interspecific mating discrimination, particularly using hybrid males. in this study, i investigated the genetic basis of sexual isolation using male hybrids of drosophila pseudoobscura and d. persimilis. hybrid male mating success was caused by interactions between the x-chromosome and autosomes (or y-chromosome), and different arms of the x-chromosome contributed to mating success with femal ... | 1997 | 28568570 |
| temporal stability of third-chromosome inversion frequencies in drosophila persimilis and d. pseudoobscura. | | 1992 | 28568997 |
| developmental variation in amylase allozyme activity associated with chromosome inversions in drosophila persimilis. | the amylase locus in drosophila persimilis is polymorphic for allozymes, two of which show associations with naturally occurring chromosome 3 inversions. amy1.09 occurs at high frequencies only in whitney (wt), while the other common arrangements-standard (st), klamath (kl) and mendocino (md)-are predominantly amy 1.00. we have examined numerous strains, representing various electromorphs and inversions, for variation in cis-specific activity expression in both third-instar larvae and adults. co ... | 1980 | 6162714 |
| chromosomal polymorphism and female receptivity in a natural population of drosophila persimilis. | in a natural population of drosophila persimilis (mcdonald ranch, napa valley, california), kl and md chromosomal arrangement frequencies undergo a seasonal cycle, with md common in spring and kl common in summer. samples collected from spring and summer provided isofemale strains established as homozygous kl and md pairs (kinlines) with each pair derived from a single heterokaryotype wild progenitor. haploid doses of chromosomes 2 and 4 were controlled by marker-cross derivations of kinlines. p ... | 1978 | 17248874 |
| microgeographic differentiation of chromosomal and enzyme polymorphisms in drosophila persimilis. | we studied microgeographic and temporal genetic differentiation in natural populations of drosophila persimilis with respect to chromosome inversion and enzyme polymorphisms. both inversion frequencies and allozyme frequencies varied significantly over short distances. neither differed significantly between morning and evening collections. because several studies of the dispersal behavior of this species have been performed, we attempt to fit the observed data to mathematical models which relate ... | 1977 | 863240 |
| gene polymorphism in natural populations of drosophila persimilis. | genetic variation at 43 loci has been studied in six different populations of drosophila persimilis by electrophoresis of enzymes and proteins. in d. persimilis the mean proportion of polymorphic loci is 0.362, the mean proportion of heterozygous loci per individual is 0.100 and the average number of alleles per locus is 1.651. in all populations, the loci coding for the hydrolytic and other nonspecific enzymes are much more variable than the loci coding for the enzymes of the glycolytic pathway ... | 1977 | 17248743 |
| lack of genic similarity between two sibling species of drosophila as revealed by varied techniques. | acrylamide gel electrophoresis was performed on the enzyme xanthine dehydrogenase in sixty isochromosomal lines of drosophila persimilis from three geographic populations. sequential electrophoretic analysis using varied gel concentrations and buffers revealed twenty-three alleles in this species where only five had been described previously. these new electrophoretic techniques also detected a profound increase in divergence of gene frequencies at this locus between d. persimilis and its siblin ... | 1976 | 1001880 |
| response of drosophila persimilis to phototactic and geotactic selection. | the initial experimental population of drosophila persimilis was photopositive and slightly geonegative. in this respect, the initial population of d. persimilis differed from the experimental population of d. pseudoobscura, described by others, which was close to photo- and geotactic neutrality. in d. persimilis as in d. pseudoobscura, photo- and geotactic selection was efficient in both positive and negative directions. in d. persimilis, unlike in d. pseudoobscura, the responses to geotactic a ... | 1975 | 1131150 |
| relative mating activity of the sexes in homokaryotypes of drosophila persimilis from a redwoods population. | previous tests for mating activity of drosophila persimilis homokaryotype kl (klamath) and md (mendocino) chromosomal arrangements (northern california population: redwoods) had shown kl to mate faster on the average than md in homogamic tests. a strain (double-cross hybrid of four kl lines from the same population) with reliable high mating activity was developed for testing the sexes separately. five pairs of kl-md homokaryotype strains were chosen to be tested by the criterion that each pair ... | 1975 | 1131148 |
| the development of mating propensity in two karyotypes of drosophila persimilis. | | 1973 | 4721567 |
| mating propensity of gene arrangement carriers from a redwoods population of drosophila persimilis. | | 1971 | 28565034 |
| quantitative variation and chromosomal arrangements in a population of drosophila persimilis from the redwoods. | | 1970 | 28562991 |
| mating propensity, chromosomal polymorphism, and dependent conditions in drosophila persimilis ii. factors between larvae and between adults. | | 1969 | 28562894 |
| genic variation in a natural population of drosophila persimilis. | the understanding of the speciation process can best be achieved by a knowledge of the genic differences between two closely related species and the correlation of such differences with the characteristics which demarcate the two species. d. persimilis and d. pseudoobscura are two sibling species differing from each other in morphology, ecological preferences, and behavior, and no hybrids exist in nature. i have compared the genetic changes in 24 loci of 25 strains of d. persimilis from mather, ... | 1969 | 5257003 |
| selection for and against ethological isolation between drosophila pseudoobscura and drosophila persimilis. | | 1966 | 28562900 |
| selection for rate of development and gene arrangement frequencies in drosophila persimilis. ii. fitness properties at equilibrium. | | 1966 | 5960259 |
| morphological variation in natural and experimental populations of drosophila pseudoobscura and drosophila persimilis. | | 1966 | 28564753 |
| chromosomal fitness changes in experimental populations of drosophila persimilis from timberline. ii. re-extracted chromosomes. | | 1966 | 28564749 |
| selection for rate of development and gene arrangement frequencies in drosophila persimilis. | | 1964 | 14239774 |
| courtship sound production in two sympatric sibling drosophila species. | courting males of drosophila persimilis produce a pulsed "vibration sound," with frequency of oscillation and pulse repetition rate markedly different from that of d. pseudoobscura. these differences probably contribute to reproductive isolation. flight frequency is the same in both species. brief "preliminary sounds" are common and the same in both species. males with large parts of both wings removed produce nearly normal vibration sounds, and normal preliminary sounds. | 1964 | 14107480 |
| release of genetic variability through recombination. ii. drosophila persimilis. | | 1959 | 17247810 |
| chromosomal adaptive polymorphism in drosophila persimilis. i. life cycle components under near optimal conditions. | | 1956 | 17247644 |
| genetics of natural populations; altitudinal and seasonal changes produced by natural selection in certain populations of drosophila persimilis. | | 1948 | 18856563 |