| linkage disequilibrium between functionally related enzyme loci of drosophila mojavensis. | gametic frequencies at four enzyme loci of the second chromosome of drosophila mojavensis race b were obtained from six localities. the four loci were selected so that they code for functionally related enzymes; two code for esterases, one for xanthine dehydrogenase and one for acetaldehyde oxidase. in drosophila the two latter enzymes are under the same regulatory control and their physiological functions might be related as well. electrophoretic variants at the locicoding for these two enzymes ... | 1976 | 990995 |
| serine esterases: structural conservation during animal evolution and variability in enzymatic properties in the genus drosophila. | both general esterases and acetylcholinesterases have been shown to be members of a homologous superfamily of serine esterases. a comparison of n-terminal sequences demonstrates that esterase-4 and -5 from drosophila mojavensis belong to this family as well, with esterase-6 and esterase-p from d. melanogaster being the closest relatives. in order to investigate the presence of immunologically related esterases in other drosophila species, crude larval extracts from five species were applied to t ... | 1990 | 2124571 |
| microbial colonization of injured cactus tissue (stenocereus gummosus) and its relationship to the ecology of cactophilic drosophila mojavensis. | necrotic tissue of agria cactus (stenocereus gummosus) serves as a feeding and breeding substrate for drosophila mojavensis. this fly species is one of the four endemic drosophila species in the sonoran desert. freeze injuries were created in arms of agria cactus in mexico to study the events of microbial colonization. facultative anaerobic bacteria were the first microbes to be detected, and the exclusion of large arthropods by covering the injuries with netting did not affect bacterial coloniz ... | 1989 | 2705763 |
| bacterial succession in necrotic tissue of agria cactus (stenocereus gummosus). | the bacterial communities associated with the development of necroses in injured agria cactus tissue were examined in the field by using both human-induced injuries and cactus tissue inoculated with cactophilic bacteria. whole-cell bacterial fatty acids were used to determine when and where each of 23 detected species occurred. this information was then used to describe successional patterns of bacterial colonization. although the number of bacterial species in human-induced injuries reached a m ... | 1994 | 8135520 |
| alcohol dehydrogenase polymorphism in barrel cactus populations of drosophila mojavensis. | starch gel electrophoresis revealed that the alcohol dehydrogenase (adh-2) locus was polymorphic in two populations (from agua caliente, california and the grand canyon, arizona) of cactophilic drosophila mojavensis that utilize barrel cactus (ferocactus acanthodes) as a host plant. electromorphs representing products of a slow (s) and a fast (f) allele were found in adult flies. the frequency of the slow allele was 0.448 in flies from agua caliente and 0.659 in flies from the grand canyon. thes ... | 1996 | 8765684 |
| ejaculate-female coevolution in drosophila mojavensis. | interspecific studies indicate that sperm morphology and other ejaculatory traits diverge more rapidly than other types of character in drosophila and other taxa. this pattern has largely been attributed to postcopulatory sexual selection involving interaction between the sexes. such divergence has been suggested to lead rapidly to reproductive isolation among populations and thus to be an 'engine of speciation.' here, we test two critical predictions of this hypothesis: (i) there is significant ... | 2003 | 12965017 |
| population genetics and geographic variation of alcohol dehydrogenase (adh) paralogs and glucose-6-phosphate dehydrogenase (g6pd) in drosophila mojavensis. | populations of drosophila mojavensis from the deserts of the baja california peninsula and mainland mexico utilize different cactus hosts with different alcohol contents. the enzyme alcohol dehydrogenase (adh) has been proposed to play an important role in the adaptation of drosophila species to their environment. this study investigates the role of adh in the adaptation of the cactophilic d. mojavensis to its cactus host. in d. mojavensis and its sibling species, d. arizonae, the adh gene has d ... | 2004 | 14660699 |
| inhibition of alcohol dehydrogenase after 2-propanol exposure in different geographic races of drosophila mojavensis: lack of evidence for selection at the adh-2 locus. | high frequencies of the fast allele of alcohol dehydrogenase-2 (adh-2f) are found in populations of drosophila mojavensis that inhabit the baja california peninsula (race bii) whereas the slow allele (adh-2s) predominates at most other localities within the species' geographic range. race bii flies utilize necrotic tissue of pitaya agria cactus (stenocereus gummosus) which contains high levels of 2-propanol, whereas flies from most other localities utilize different cactus hosts in which 2-propa ... | 2005 | 15726639 |
| activity variation in alcohol dehydrogenase paralogs is associated with adaptation to cactus host use in cactophilic drosophila. | drosophila mojavensis and drosophila arizonae are species of cactophilic flies that share a recent duplication of the alcohol dehydrogenase (adh) locus. one paralog (adh-2) is expressed in adult tissues and the other (adh-1) in larvae and ovaries. enzyme activity measurements of the adh-2 amino acid polymorphism in d. mojavensis suggest that the fast allozyme allele has a higher activity on 2-propanol than 1-propanol. the fast allele was found at highest frequency in populations that utilize hos ... | 2005 | 15910339 |
| larval selectivity for yeast species by drosophila mojavensis in natural substrates. | the yeast flora found in the major substrates of drosophila mojavensis and in larval guts was studied both qualitatively and quantitatively. quantitative studies show that, in four of the five substrates tested, the larvae did not contain a random sample of the yeasts present in the substrates. one widely distributed cactus yeast, pichia cactophila, was typically in greater frequency in the larvae than in the substrates. another cactus yeast, candida sonorensis, typically exhibited the opposite ... | 1981 | 16593060 |
| microsatellite variation among diverging populations of drosophila mojavensis. | divergence and speciation may occur by various means, depending on the particular history, selective environments, and genetic composition of populations. in drosophila mojavensis, a good model of incipient speciation, understanding the population genetic structure within this group facilitates our ability to understand the context in which reproductive isolation among populations is developing. here we report the genetic structure and relationships of d. mojavensis populations at nuclear loci. ... | 2006 | 16910998 |
| sympatry, allopatry and sexual isolation between drosophila mojavensis and d. arizonae. | populations of the north american cactophilic fruitfly drosophila mojavensis and its sibling species d. arizonae exist both in sympatry and in allopatry. females of d. arizonae, regardless of their population of origin, are effectively completely isolated behaviorally from d. mojavensis males. on the other hand, females of d. mojavensis from the sympatric populations in sonora, mexico exhibit significantly stronger premating isolation from d. arizonae males than do d. mojavensis females from all ... | 2005 | 16970612 |
| evolutionary relationships of drosophila mojavensis geographic host races and their sister species drosophila arizonae. | the cactophilic drosophila mojavensis species group living in the deserts and dry tropical forests of the southwestern united states and mexico provides a valuable system for studies in diversification and speciation. rigorous studies of the relationships between host races of d. mojavensis and the relationships among the members of the species group (d. mojavensis, drosophila arizona, and drosophila navojoa) are lacking. we used mitochondrial co1 sequence data to address the phylogenetics and p ... | 2007 | 17305857 |
| the molecular basis of host adaptation in cactophilic drosophila: molecular evolution of a glutathione s-transferase gene (gstd1) in drosophila mojavensis. | drosophila mojavensis is a cactophilic fly endemic to the northwestern deserts of north america. this species includes four genetically isolated cactus host races each individually specializing on the necrotic tissues of a different cactus species. the necrosis of each cactus species provides the resident d. mojavensis populations with a distinct chemical environment. a previous investigation of the role of transcriptional variation in the adaptation of d. mojavensis to its hosts produced a set ... | 2008 | 18245335 |
| deep rna-seq profile reveals biodiversity, plant-microbe interactions and a large family of nbs-lrr resistance genes in walnut (juglans regia) tissues. | deep rna-seq profiling, a revolutionary method used for quantifying transcriptional levels, often includes non-specific transcripts from other co-existing organisms in spite of stringent protocols. using the recently published walnut genome sequence as a filter, we present a broad analysis of the rna-seq derived transcriptome profiles obtained from twenty different tissues to extract the biodiversity and possible plant-microbe interactions in the walnut ecosystem in california. since the residua ... | 2016 | 26883051 |
| postmating transcriptional changes in reproductive tracts of con- and heterospecifically mated drosophila mojavensis females. | in internally fertilizing organisms, mating involves a series of highly coordinated molecular interactions between the sexes that occur within the female reproductive tract. in species where females mate multiply, traits involved in postcopulatory interactions are expected to evolve rapidly, potentially leading to postmating-prezygotic (pmpz) reproductive isolation between diverging populations. here, we investigate the postmating transcriptional response of the lower reproductive tract of droso ... | 2011 | 21518862 |
| molecular population genetics of accessory gland protein genes and testis-expressed genes in drosophila mojavensis and d. arizonae. | molecular population genetic investigation of drosophila male reproductive genes has focused primarily on melanogaster subgroup accessory gland protein genes (acp's). consistent with observations from male reproductive genes of numerous taxa, acp's evolve more rapidly than nonreproductive genes. however, within the drosophila genus, large data sets from additional types of male reproductive genes and from different species groups are lacking. here we report findings from a molecular population g ... | 2005 | 16085702 |
| 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 |
| characterization and expression analysis of prohibitin in the testis of chinese mitten crab eriocheir sinensis. | prohibitin plays a key role in maintaining mitochondrial membrane integrity and retaining its normal function. we have initially cloned and sequenced the cdna of prohibitin from testis of the crab eriocheir sinensis. the 1,357 bp prohibitin cdna comprises a 105 bp 5' untranslated region, a 427 bp 3' untranslated region and a 825 bp open reading frame. protein alignment substantiates that the prohibitin has 70.2, 69.8, 70.5, 70.9, 72.4, 70.6 and 74.9% identity with its homologues in mus musculus, ... | 2012 | 22311031 |
| two phases of aging separated by the smurf transition as a public path to death. | aging's most obvious characteristic is the time dependent increase of an individual's probability to die. this lifelong process is accompanied by a large number of molecular and physiological changes. although numerous genes involved in aging have been identified in the past decades its leading factors have yet to be determined. to identify the very processes driving aging we have developed in the past years an assay to identify physiologically old individuals in a synchronized population of dro ... | 2016 | 27002861 |
| comparative genomic analysis of allatostatin-encoding (ast) genes in drosophila species and prediction of regulatory elements by phylogenetic footprinting. | the role of the yxfgla family of allatostatin (ast) peptides in dipterans is not well-established. the recent completion of sequencing of genomes for multiple drosophila species provides an opportunity to study the evolutionary variation of the allatostatins and to examine regulatory elements that control gene expression. we performed comparative analyses of ast genes from seven drosophila species (drosophila melanogaster, drosophila simulans, drosophila ananassae, drosophila yakuba, drosophila ... | 2007 | 17175069 |
| molecular evolution of candidate genes involved in post-mating-prezygotic reproductive isolation. | traits involved in post-copulatory interactions between the sexes may evolve rapidly as a result of sexual selection and/or sexual conflict, leading to post-mating-prezygotic (pmpz) reproductive isolating barriers between diverging lineages. although the importance of pmpz isolation is recognized, the molecular basis of such incompatibilities is not well understood. here, we investigate molecular evolution of a subset of drosophila mojavensis and drosophila arizonae reproductive tract genes. the ... | 2015 | 25522894 |
| proteomic analysis of drosophila mojavensis male accessory glands suggests novel classes of seminal fluid proteins. | fruit-flies of the genus drosophila are characterized by overwhelming variation in fertilization traits such as copulatory plug formation, sperm storage organ use, and nutritional ejaculatory donation. despite extensive research on the genetic model drosophila melanogaster, little is known about the molecular underpinnings of these interspecific differences. this study employs a proteomic approach to pin-point candidate seminal fluid proteins in drosophila mojavensis, a cactophilic fruit-fly tha ... | 2009 | 19328853 |
| localization and characterization of x chromosome inversion breakpoints separating drosophila mojavensis and drosophila arizonae. | ectopic exchange between transposable elements or other repetitive sequences along a chromosome can produce chromosomal inversions. as a result, genome sequence studies typically find sequence similarity between corresponding inversion breakpoint regions. here, we identify and investigate the breakpoint regions of the x chromosome inversion distinguishing drosophila mojavensis and drosophila arizonae. we localize one inversion breakpoint to 13.7 kb and localize the other to a 1-mb interval. usin ... | 2009 | 17194790 |
| the effect of thermal stress on the mating behavior of three drosophila species. | selection may act on the weakest link in fitness to change how a species adapts to an environmental stress. for many species, this limitation may be reproduction. after adult drosophila melanogaster, drosophila simulans, and drosophila mojavensis males were exposed to varying levels of thermal stress well below those that endanger life, courtship and mating frequency declined. the regression coefficients of both courtship and mating success did not differ significantly between d. melanogaster an ... | 2006 | 11731970 |
| effects of temperature on cuticular lipids and water balance in a desert drosophila: is thermal acclimation beneficial? | the desert fruit fly drosophila mojavensis experiences environmental conditions of high temperature and low humidity. to understand the physiological mechanisms allowing these small insects to survive in such stressful conditions, we studied the effects of thermal acclimation on cuticular lipids and rates of water loss of adult d. mojavensis. mean hydrocarbon chain length increased at higher temperatures, but cuticular lipid melting temperature (tm) did not. lipid quantity doubled in the first 1 ... | 1998 | 9390938 |
| delineation of cis-acting sequences required for expression of drosophila mojavensis adh-1. | the control of expression of the adh-1 gene of drosophila mojavensis has been analyzed by transforming adh null drosophila melanogaster hosts with p element constructs which contain d. mojavensis adh-1 having deletions of different extent in the 5' and 3' ends. adh-1 expression in the d. melanogaster hosts is qualitatively similar to expression in d. mojavensis, although expression is quantitatively lower in transformants. deletions of the 5' end indicate that information required for normal tem ... | 1992 | 1317314 |
| ecological aspects of cactus triterpene glycosides i. their effect on fitness components ofdrosophila mojavensis. | the effects of pentacyclic triterpene glycosides extracted from agria and organ pipe cacti on three fitness parameters of the cactophilic fruit fly,drosophila mojavensis were tested. triterpene glycosides from organ pipe increased development time and reduced larval viability while those from agria produced smaller adults (reduced fecundity). in addition, the microbial communities in the organ pipe saponin media were less dense than those in the media to which agria saponins had been added. the ... | 1989 | 24271807 |
| structure and evolution of the adh genes of drosophila mojavensis. | the nucleotide sequence of the adh region of drosophila mojavensis has been completed and the region found to contain a pseudogene, adh-2 and adh-1 arranged in that order. comparison of the sequence divergence of these genes to one another and to the adh region of drosophila mulleri and other species has allowed the development of a model for the evolution of the duplication of the adh genes. there have been two major events. an initial duplication of an adh gene whose dual promoter structure wa ... | 1988 | 3224808 |
| drosophila males contribute to oogenesis in a multiple mating species. | two species of drosophila that differ in their ecology and mating systems have been compared with respect to male contribution to the somatic tissues and developing oocytes of females. in the species drosophila mojavensis females remate daily, exhibit a copulatory plug, and have been shown to obtain a contribution from the male ejaculate. in contrast, drosophila melanogaster males do not contribute to females. female drosophila melanogaster do not remate as frequently as drosophila mojavensis fe ... | 1984 | 17734916 |
| lipidomic profiles of drosophila melanogaster and cactophilic fly species: models of human metabolic diseases. | the metabolic syndrome (mets) is associated with serious diseases and represents an important threat for global public health. the common fruit fly (drosophila melanogaster) has served as a model organism to study physiological processes of the mets, because central metabolic pathways are conserved among species, and because the flies are easy to cultivate in a laboratory. in nature, d. melanogaster is a fruit generalist, feeding on diets rich in simple carbohydrates. other drosophilids, however ... | 2017 | 29043354 |
| genome-wide tests for introgression between cactophilic drosophila implicate a role of inversions during speciation. | models of speciation-with-gene-flow have shown that the reduction in recombination between alternative chromosome arrangements can facilitate the fixation of locally adaptive genes in the face of gene flow and contribute to speciation. however, it has proven frustratingly difficult to show empirically that inversions have reduced gene flow and arose during or shortly after the onset of species divergence rather than represent ancestral polymorphisms. here, we present an analysis of whole genome ... | 2015 | 25824653 |
| evolution of reproductive morphology among recently diverged taxa in the drosophila mojavensis species cluster. | the morphological evolution of sexual traits informs studies of speciation due to the potential role of these characters in reproductive isolation. in the current study, we quantified and compared genitalic variation within the drosophila mojavensis species cluster to infer the mode of evolution of the male aedeagus. this system is ideal for such studies due to the opportunity to test and compare levels of variation along a divergence continuum at various taxonomic levels within the group. shape ... | 2012 | 22423332 |
| reproductive tract and spermatid abnormalities of hybrid males from reciprocal crosses between drosophila mojavensis and d. arizonae. | hybrid males from reciprocal crosses of specific strains of the closely related species drosophila mojavensis and drosophila arizonae are sterile. the sterile hybrid males exhibit testis and seminal vesicle phenotypes that differ from their parental strains and from each other both in lengths of the organs and the development of the spermatids as seen in light and electron microscopy. incompatibilities affecting spermiogenesis differ in reciprocal crosses, suggesting that hybrid male sterility m ... | 2011 | 21540637 |
| post-zygotic isolation in cactophilic drosophila: larval viability and adult life-history traits of d. mojavensis/d. arizonae hybrids. | drosophila mojavensis and drosophila arizonae are cactophilic flies that have been used extensively in speciation studies. incomplete premating isolation, evidence of reinforcement, and a lack of recent introgression between these species point to a potentially important role for post-zygotic isolating barriers in this system. other than hybrid male sterility, however, post-zygotic isolation between d. mojavensis and d. arizonae has received little attention. in this study, we examined viability ... | 2009 | 19508411 |
| multilocus nuclear sequences reveal intra- and interspecific relationships among chromosomally polymorphic species of cactophilic drosophila. | drosophila mojavensis and drosophila arizonae, a pair of sibling species endemic to north america, constitute an important model system to study ecological genetics and the evolution of reproductive isolation. this species pair can produce fertile hybrids in some crosses and are sympatric in a large part of their ranges. despite the potential for hybridization in nature, however, evidence of introgression has not been rigorously sought. further, the evolutionary relationships within and among th ... | 2007 | 17614914 |
| multilocus test for introgression between the cactophilic species drosophila mojavensis and drosophila arizonae. | information obtained from laboratory studies regarding the efficacy of barriers to gene flow (reproductive isolation) between species is often incomplete or misleading, so detailed genetic analyses are needed to determine whether hybridization and introgression occur in nature. previous laboratory studies of the cactophilic species drosophila mojavensis and drosophila arizonae suggest that reproductive isolation is incomplete and that gene flow may occur in sympatry. we sampled 18 nuclear and on ... | 2006 | 17080365 |
| early events in speciation: polymorphism for hybrid male sterility in drosophila. | capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. we have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. specifically, we show that the occurrence of hybrid male sterility in crosses between drosophila mojavensis and its sister species, drosophila arizonae, is controlled by factors pres ... | 2004 | 15184657 |
| hierarchical structure in the drosophila mojavensis cluster (diptera: drosophilidae). | sequences from three gene regions from the nuclear and mitochondrial genomes were used to examine the extent and nature of hierarchical structure in the drosophilamojavensis cluster (drosophila arizonae, d. mojavensis and d. navojoa) of the d. repleta species group. to determine the genetic divergence of these three species, sequence data were analyzed using maximum parsimony and population aggregation analysis. individual and combined gene genealogies indicate that d. arizonae and d. mojavensis ... | 2003 | 15061805 |
| sexually antagonistic coevolution of a postmating-prezygotic reproductive character in desert drosophila. | rapid divergence in postmating-prezygotic characters suggests that selection may be responsible for generating reproductive barriers between closely related species. theoretical models indicate that this rapid divergence could be generated by a series of male adaptations and female counteradaptations by means of sexual selection or conflict, but empirical tests of particular mechanisms are generally lacking. moreover, although a male--female genotypic interaction in mediating sperm competition a ... | 2001 | 11447265 |
| an autosomal factor from drosophila arizonae restores normal spermatogenesis in drosophila mojavensis males carrying the d. arizonae y chromosome. | males of drosophila mojavensis whose y chromosome is replaced by the y chromosome of the sibling species drosophila arizonae are sterile. it is shown that genetic material from the fourth chromosome of d. arizonae is necessary and sufficient, in single dose, to restore fertility in these males. in introgression and mapping experiments this material segregates as a single mendelian factor (sperm motility factor, smf). light and electron microscopy studies of spermatogenesis in d. mojavensis males ... | 1993 | 8514139 |
| genomics of ecological adaptation in cactophilic drosophila. | cactophilic drosophila species provide a valuable model to study gene-environment interactions and ecological adaptation. drosophila buzzatii and drosophila mojavensis are two cactophilic species that belong to the repleta group, but have very different geographical distributions and primary host plants. to investigate the genomic basis of ecological adaptation, we sequenced the genome and developmental transcriptome of d. buzzatii and compared its gene content with that of d. mojavensis and two ... | 2014 | 25552534 |
| striking structural dynamism and nucleotide sequence variation of the transposon galileo in the genome of drosophila mojavensis. | | 2013 | 23374229 |
| cloning and sequencing of the breakpoint regions of inversion 5g fixed in drosophila buzzatii. | chromosomal inversions are ubiquitous in drosophila both as intraspecific polymorphisms and interspecific differences. many gaps still remain in our understanding of the mechanisms that generate them. previous work has shown that in drosophila buzzatii, three polymorphic inversions were generated by ectopic recombination between copies of the transposon galileo. in this study, we have characterized the breakpoint regions of inversion 5g, fixed in d. buzzatii and absent in drosophila koepferae an ... | 2009 | 19198866 |
| characterization of the structure and evolution of the adh region of drosophila hydei. | drosophila of the repleta group have a duplication of the gene which encodes alcohol dehydrogenase (adh). we report the nucleotide sequence of an 8.4-kb region of genomic dna of drosophila hydei which includes the entire adh region. analysis of this sequence reveals similarity in organization to the adh region of drosophila mojavensis and drosophila mulleri of the mulleri subgroup, with three genes ordered 5' to 3', adh-psi, adh-2, adh-1. deletion of a nucleotide in the second codon of each pseu ... | 1991 | 2004708 |
| involvement of cytochrome p450 in host-plant utilization by sonoran desert drosophila. | the four drosophila species endemic to the sonoran desert (drosophila mettleri, drosophila mojavensis, drosophila nigrospiracula, and drosophila pachea) utilize necrotic cactus tissue or soil soaked by rot exudate as breeding substrates. each drosophila species uses a different cactus species as its primary host. d. pachea is limited to senita cactus by a biochemical dependency on unusual sterols available only in that cactus. for the other drosophila species, no such chemical dependencies exist ... | 1992 | 1465429 |
| evolution of gstd1 in cactophilic drosophila. | gstd1 is an insect glutathione s-transferase that has received considerable attention because of its role in detoxification of xenobiotic compounds, specifically pesticides and plant allelochemicals involved in detoxification, or in the use of some substrates as a nutritional source. gstd1 has been implicated in the adaptation to a new cactus host in drosophila mojavensis and thus constitutes an interesting candidate to study ecological genetics of adaptation in drosophila. we conducted populati ... | 2017 | 28660301 |
| population differences in host plant preference and the importance of yeast and plant substrate to volatile composition. | divergent selection between environments can result in changes to the behavior of an organism. in many insects, volatile compounds are a primary means by which host plants are recognized and shifts in plant availability can result in changes to host preference. both the plant substrate and microorganisms can influence this behavior, and host plant choice can have an impact on the performance of the organism. in drosophila mojavensis, four geographically isolated populations each use different ca ... | 2017 | 28616178 |
| effects of temperature on transcriptome and cuticular hydrocarbon expression in ecologically differentiated populations of desert drosophila. | we assessed the effects of temperature differences on gene expression using whole-transcriptome microarrays and cuticular hydrocarbon variation in populations of cactophilic drosophila mojavensis. four populations from baja california and mainland mexico and arizona were each reared on two different host cacti, reared to sexual maturity on laboratory media, and adults were exposed for 12 hr to 15, 25, or 35°c. temperature differences influenced the expression of 3,294 genes, while population dif ... | 2017 | 28116058 |
| population differences in olfaction accompany host shift in drosophila mojavensis. | evolutionary shifts in plant-herbivore interactions provide a model for understanding the link among the evolution of behaviour, ecological specialization and incipient speciation. drosophila mojavensis uses different host cacti across its range, and volatile chemicals emitted by the host are the primary cue for host plant identification. in this study, we show that changes in host plant use between distinct d. mojavensis populations are accompanied by changes in the olfactory system. specifical ... | 2016 | 27581882 |
| preadult life history variation determines adult transcriptome expression. | preadult determinants of adult fitness and behaviour have been documented in a variety of organisms with complex life cycles, but little is known about expression patterns of genes underlying these adult traits. we explored the effects of differences in egg-to-adult development time on adult transcriptome and cuticular hydrocarbon variation in order to understand the nature of the genetic correlation between preadult development time and premating isolation between populations of drosophila moja ... | 2016 | 26615085 |
| the role of aedeagus size and shape in failed mating interactions among recently diverged taxa in the drosophila mojavensis species cluster. | investigating the evolution of species-specific insect genitalia is central to understanding how morphological diversification contributes to reproductive isolation and lineage divergence. while many studies evoke some form of sexual selection to explain genitalia diversity, the basis of selection and the mechanism of heterospecific mate exclusion remains vague. i conducted reciprocal mate pair trials in the drosophila mojavensis species cluster to quantify the frequency of failed insemination a ... | 2014 | 25491379 |
| deciphering life history transcriptomes in different environments. | we compared whole transcriptome variation in six pre-adult stages and seven adult female ages in two populations of cactophilic drosophila mojavensis reared on two host plants to understand how differences in gene expression influence standing life history variation. we used singular value decomposition (svd) to identify dominant trajectories of life cycle gene expression variation, performed pairwise comparisons of stage and age differences in gene expression across the life cycle, identified w ... | 2015 | 25442828 |
| premating isolation is determined by larval rearing substrates in cactophilic drosophila mojavensis. x. age-specific dynamics of adult epicuticular hydrocarbon expression in response to different host plants. | analysis of sexual selection and sexual isolation in drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (chcs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. flies were never exposed to ... | 2014 | 25360246 |
| characterization of volatiles of necrotic stenocereus thurberi and opuntia littoralis and toxicity and olfactory preference of drosophila melanogster, d. mojavensis wrigleyi, and d. mojavensis sonorensis to necrotic cactus volatiles. | drosophila mojavensis wrigleyi and d. mojavensis sonorensis are geographically separated races of cactophilic fruit flies. d. mojavensis sonorensis inhabits the sonoran desert and utilizes necrotic rots of stenocereus thurberi engelm. as a food source and to oviposit while d. mojavensis wrigleyi inhabits santa catalina island, california and utilizes the necrotic rots of opuntia littoralis (engelm.) cockerell. the objectives of this study were to determine the volatile compositions of the necrot ... | 2014 | 25233605 |
| no boundaries: genomes, organisms, and ecological interactions responsible for divergence and reproductive isolation. | revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype-phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic eleme ... | 2014 | 25149252 |
| the drosophila mojavensis bari3 transposon: distribution and functional characterization. | bari-like transposons belong to the tc1-mariner superfamily, and they have been identified in several genomes of the drosophila genus. this transposon's family has been used as paradigm to investigate the complex dynamics underlying the persistence and structural evolution of transposable elements (tes) within a genome. three structural bari variants have been identified so far and can be distinguished based on the organization of their terminal inverted repeats. bari3 is the last discovered mem ... | 2014 | 25093043 |
| ecological genomics of host shifts in drosophila mojavensis. | advances in next-generation sequencing technologies have liberated our dependency on model laboratory species for answering genomic and transcriptomic level questions. these new techniques have dramatically expanded our breadth of study organisms and have allowed the analysis of species from diverse ecological environments. one such species is the cactophilic drosophila mojavensis that inhabits the deserts of western north america. these insects feed and develop in the necrotic cacti, feeding la ... | 2014 | 24277303 |
| divergence in olfactory host plant preference in d. mojavensis in response to cactus host use. | divergence in host adaptive traits has been well studied from an ecological and evolutionary perspective, but identification of the proximate mechanisms underlying such divergence is less well understood. behavioral preferences for host plants are often mediated by olfaction and shifts in preference may be accompanied by changes in the olfactory system. in this study, we examine the evolution of host plant preferences in cactophilic drosophila mojavensis that feeds and breeds on different cacti ... | 2013 | 23936137 |
| transcriptome-wide expression variation associated with environmental plasticity and mating success in cactophilic drosophila mojavensis. | ecological speciation occurs with the adaptation of populations to different environments and concurrent evolution of reproductive isolation. phenotypic plasticity might influence both ecological adaptation and reproductive traits. we examined environment-specific gene expression and male mating success in cactophilic drosophila mojavensis using transcriptome sequencing. this species exhibits cactus-dependent mating success across different species of host plants, with genotype-by-environment in ... | 2013 | 23815652 |
| functional genomic and phenotypic responses to desiccation in natural populations of a desert drosophilid. | we used whole-transcriptome microarrays to assess changes in gene expression and monitored mortality rates and epicuticular hydrocarbons (chcs) in response to desiccation stress in four natural populations of drosophila mojavensis from baja california and mainland mexico. desiccation had the greatest effect on gene expression, followed by biogeographical variation at regional and population levels. genes involved in environmental sensing and cuticular structure were up-regulated in dry condition ... | 2013 | 23505972 |
| premating isolation is determined by larval rearing substrates in cactophilic drosophila mojavensis. ix. host plant and population specific epicuticular hydrocarbon expression influences mate choice and sexual selection. | sexual signals in cactophilic drosophila mojavensis include cuticular hydrocarbons (chcs), contact pheromones that mediate female discrimination of males during courtship. chcs, along with male courtship songs, cause premating isolation between diverged populations, and are influenced by genotype × environment interactions caused by different host cacti. chc profiles of mated and unmated adult flies from a baja california and a mainland mexico population of d. mojavensis reared on two host cacti ... | 2013 | 23286346 |
| model-based comparisons of phylogeographic scenarios resolve the intraspecific divergence of cactophilic drosophila mojavensis. | the cactophilic fly drosophila mojavensis exhibits considerable intraspecific genetic structure across allopatric geographic regions and shows associations with different host cactus species across its range. the divergence between these populations has been studied for more than 60years, yet their exact historical relationships have not been resolved. we analysed sequence data from 15 intronic x-linked loci across populations from baja california, mainland sonora-arizona and mojave desert regio ... | 2012 | 22571504 |
| population transcriptomics of cactus host shifts in drosophila mojavensis. | in the presence of environmental change, natural selection can shape the transcriptome. under a scenario of environmental change, genotypes that are better able to modulate gene expression to maximize fitness will tend to be favoured. therefore, it is important to examine gene expression at the population level to distinguish random or neutral gene expression variation from the pattern produced by natural selection. this study investigates the natural variation in transcriptional response to a c ... | 2012 | 22512269 |
| mate choice opportunity leads to shorter offspring development time in a desert insect. | we describe indirect genetic benefits of mate choice in two allopatric populations of cactophilic drosophila mojavensis. by manipulating mate choice opportunity, we show that greater mate choice among sexually mature adults leads to shorter offspring egg-to-adult development times; the extent of this reduction was influenced by population origin and by host plant environment. we performed multiple-choice mating trials with individually marked flies to investigate whether differential male mating ... | 2011 | 21481056 |
| diversity-enhancing selection acts on a female reproductive protease family in four subspecies of drosophila mojavensis. | protein components of the drosophila male ejaculate are critical modulators of reproductive success, several of which are known to evolve rapidly. recent evidence of adaptive evolution in female reproductive tract proteins suggests this pattern may reflect sexual selection at the molecular level. here we explore the evolutionary dynamics of a five-paralog gene family of female reproductive proteases within geographically isolated subspecies of drosophila mojavensis. remarkably, four of five para ... | 2011 | 21212232 |
| genetics of incipient speciation in drosophila mojavensis. iii. life-history divergence in allopatry and reproductive isolation. | we carried out a three-tiered genetic analysis of egg-to-adult development time and viability in ancestral and derived populations of cactophilic drosophila mojavensis to test the hypothesis that evolution of these life-history characters has shaped premating reproductive isolation in this species. first, a common garden experiment with 11 populations from baja california and mainland mexico and arizona reared on two host species revealed significant host plant x region and population interactio ... | 2010 | 20681983 |
| transcriptional regulation of metabolism associated with the increased desiccation resistance of the cactophilic drosophila mojavensis. | in drosophila, adaptation to xeric environments presents many challenges, greatest among them the maintenance of water balance. drosophila mojavensis, a cactophilic species from the deserts of north america, is one of the most desiccation resistant in the genus, surviving low humidity primarily by reducing its metabolic rate. genetic control of reduced metabolic rate, however, has yet to be elucidated. we utilized the recently sequenced genome of d. mojavensis to create an oligonucleotide microa ... | 2009 | 19487561 |
| genetics of incipient speciation in drosophila mojavensis: ii. host plants and mating status influence cuticular hydrocarbon qtl expression and g x e interactions. | we performed a quantitative trait locus (qtl) analysis of epicuticular hydrocarbon variation in 1650 f(2) males from crosses of baja california and mainland mexico populations of drosophila mojavensis cultured on two major host cacti. principal component (pc) analysis revealed five pcs that accounted for 82% of the total epicuticular hydrocarbon variation. courtship trials with mainland females were used to characterize hydrocarbon profiles of mated and unmated f(2) males, and logistic regressio ... | 2009 | 19228188 |
| duplication, selection and gene conversion in a drosophila mojavensis female reproductive protein family. | protein components of the drosophila male ejaculate, several of which evolve rapidly, are critical modulators of reproductive success. recent studies of female reproductive tract proteins indicate they also are extremely divergent between species, suggesting that reproductive molecules may coevolve between the sexes. our current understanding of intersexual coevolution, however, is severely limited by the paucity of genetic and evolutionary studies on the female molecules involved. physiological ... | 2009 | 19204376 |
| premating isolation is determined by larval rearing substrates in cactophilic drosophila mojavensis. iv. correlated responses in behavioral isolation to artificial selection on a life-history trait. | studies of behavioral isolation among geographically isolated populations of drosophila mojavensis have provided an understanding of incipient speciation wherein phylogeny and ecology play a prominent role. populations of d. mojavensis in mainland mexico and southern arizona exhibit low but significant premating isolation from baja california populations in laboratory mate choice tests. these same populations have undergone considerable life-history evolution in response to use of different host ... | 1998 | 18811406 |
| premating isolation is determined by larval rearing substrates in cactophilic drosophila mojavensis. viii. mating success mediated by epicuticular hydrocarbons within and between isolated populations. | we tested the hypothesis that intrademic sexual selection has caused sexual isolation between populations of geographically isolated populations of cactophilic drosophila mojavensis, and was mediated by epicuticular hydrocarbons (ehcs), contact pheromones in this system. sexual selection and sexual isolation were estimated using a baja california and mainland population by comparing the number of mated and unmated males and females in each of four pairwise population mating trials. ehc profiles ... | 2008 | 18713239 |
| premating isolation is determined by larval-rearing substrates in cactophilic drosophila mojavensis. v. deep geographic variation in epicuticular hydrocarbons among isolated populations. | adult epicuticular hydrocarbon variation of 14 geographically isolated populations of cactophilic drosophila mojavensis was assessed to further investigate mechanisms of sexual isolation. hydrocarbon transfer experiments demonstrated that these compounds are part of the mate recognition system in this species. sixteen of the 23 epicuticular hydrocarbon components studied differed in amounts between males and females, and 13 differed in quantity between the geographic regions encompassing baja ca ... | 2001 | 18707353 |
| sequence signatures of a recent chromosomal rearrangement in drosophila mojavensis. | the x-chromosome inversion, xe, distinguishes drosophila mojavensis and d. arizonae. earlier work mapped the breakpoints of this inversion to large intervals and provided hypotheses for the locations of the breakpoints within 3000-bp intergenic regions on the d. mojavensis genome sequence assembly. here, we sequenced these regions directly in the putatively ancestral d. arizonae x-chromosome. we find that the two inversion breakpoints are near an inverted gene duplication and a common repetitive ... | 2009 | 18661244 |
| adaptive evolution of recently duplicated accessory gland protein genes in desert drosophila. | the relationship between animal mating system variation and patterns of protein polymorphism and divergence is poorly understood. drosophila provides an excellent system for addressing this issue, as there is abundant interspecific mating system variation. for example, compared to d. melanogaster subgroup species, repleta group species have higher remating rates, delayed sexual maturity, and several other interesting differences. we previously showed that accessory gland protein genes (acp's) of ... | 2007 | 17720912 |
| genetics of incipient speciation in drosophila mojavensis. i. male courtship song, mating success, and genotype x environment interactions. | few studies have examined genotype by environment (gxe) effects on premating reproductive isolation and associated behaviors, even though such effects may be common when speciation is driven by adaptation to different environments. in this study, mating success and courtship song differences among diverging populations of drosophila mojavensis were investigated in a two-environment quantitative trait locus (qtl) analysis. baja california and mainland mexico populations of d. mojavensis feed and ... | 2007 | 17492965 |
| conflict between direct and indirect benefits of female choice in desert drosophila. | identifying the factors that contribute to the adaptive significance of mating preferences is one major goal of evolutionary research and is largely unresolved. both direct and indirect benefits can contribute to mate choice evolution. failure to consider the interaction between individual consequences of mate choice may obscure the opposing effects of individual costs and benefits. we investigate direct and indirect fitness effects of female choice in a desert fly (drosophila mojavensis), a spe ... | 2007 | 17443958 |
| premating isolation is determined by larval rearing substrates in cactophilic drosophila mojavensis. vii. effects of larval dietary fatty acids on adult epicuticular hydrocarbons. | low concentrations of dietary triacylglycerols including tristearin, triolein, and tripalmitolein, were assessed to determine their effects during egg to pupal stages on adult epicuticular hydrocarbon (ehc) variation in cactophilic drosophila mojavensis. triacylglycerols were added singly and in combination at concentrations of 1%, 3%, and 9% to a lipid-free culture medium. control diets included carolina drosophila and lipid-free media. egg to adult viability was reduced at triacylglycerol conc ... | 2006 | 17131188 |
| functional genomics of cactus host shifts in drosophila mojavensis. | understanding the genetic basis of adaptation to novel environments remains one of the major challenges confronting evolutionary biologists. while newly developed genomic approaches hold considerable promise for addressing this overall question, the relevant tools have not often been available in the most ecologically interesting organisms. our study organism, drosophila mojavensis, is a cactophilic sonoran desert endemic utilizing four different cactus hosts across its geographical range. its w ... | 2006 | 17107489 |
| multiple paternity in wild-caught drosophila mojavensis. | female remating frequency and sperm allocation patterns can strongly influence levels of sperm competition and reproductive success in natural populations. in the laboratory, drosophila mojavensis males transfer very few sperm per copulation and females remate often, suggesting multiple paternity should be common in nature. here, we examine female sperm loads, incidence of multiple paternity, and sperm utilization by genotyping progeny from 20 wild-caught females at four highly polymorphic micro ... | 2006 | 16780438 |
| a microsatellite linkage map of drosophila mojavensis. | drosophila mojavensis has been a model system for genetic studies of ecological adaptation and speciation. however, despite its use for over half a century, no linkage map has been produced for this species or its close relatives. | 2004 | 15163351 |
| quantitative genetic analysis of among-population variation in sperm and female sperm-storage organ length in drosophila mojavensis. | in drosophila, sperm length and the length of the females' primary sperm-storage organ have rapidly coevolved through post-copulatory sexual selection. this pattern is evident even among geographic populations of drosophila mojavensis. to understand better these traits of potential importance for speciation, we performed quantitative genetic analysis of both seminal receptacle length and sperm length in two divergent populations. parental strains, f1, f1 reciprocal (f1r), f2, f2r, backcross and ... | 2003 | 12929912 |
| sequence variation of alcohol dehydrogenase (adh) paralogs in cactophilic drosophila. | this study focuses on the population genetics of alcohol dehydrogenase (adh) in cactophilic drosophila. drosophila mojavensis and d. arizonae utilize cactus hosts, and each host contains a characteristic mixture of alcohol compounds. in these drosophila species there are two functional adh loci, an adult form (adh-2) and a larval and ovarian form (adh-1). overall, the greater level of variation segregating in d. arizonae than in d. mojavensis suggests a larger population size for d. arizonae. th ... | 2003 | 12586706 |
| epicuticular hydrocarbon variation in drosophila mojavensis cluster species. | epicuticular hydrocarbon variation was investigated among the three species of the drosophila mojavensis cluster (d. mojavensis, d. arizonae, and d. navojoa) within the large d. repleta group. because these hydrocarbons serve as contact pheromones in adult d. mojavensis, the chemical characteristics and differences in hydrocarbon profiles in populations of these three sibling species were further investigated. twenty-seven hydrocarbon components with chain lengths ranging from c28 to c40, includ ... | 2001 | 11710615 |
| genetics of host-cactus response and life-history evolution among ancestral and derived populations of cactophilic drosophila mojavensis. | the extent of host-specific genetic variation for two life-history traits, egg to adult developmental time and viability, and one morphological trait closely tied to fitness, adult thorax size, was exposed by employing a nested half-sib/full-sib breeding design with baja and mainland populations of drosophila mojavensis recently extracted from nature. this study was motivated by the presence of substantial variation in life histories among populations of d. mojavensis that use the fermenting tis ... | 1993 | 28567893 |
| premating isolation is determined by larval substrates in cactophilic drosophila mojavensis. | | 1992 | 28567750 |
| remating effects on the genetic structure of female life histories in populations of drosophila mojavensis. | a quantitative genetic analysis of nine adult fitness components was performed in two populations of cactophilic drosophila mojavensis under natural conditions of fermenting cactus and ethanol vapour. female progeny from 18 sires and 36 dams were treated to a range of six exposure periods to males to assess effects of remating frequency on female fitness. lifetime fecundity increased with increasing male exposure, but longevity showed an intermediate optimum with temporary exposure to males of 2 ... | 1992 | 1612926 |
| sexual isolation among populations of drosophila mojavensis. | | 1991 | 28563820 |
| courtship behavior and control of reproductive isolation in drosophila mojavensis: genetic analysis of population hybrids. | drosophila mojavensis from the sonora region and baja california show asymmetrical sexual isolation in the laboratory: males from sonora mate equally frequently with sonora and baja females, while the mating success of baja males with sonora females is reduced. this failure has been localized to three separate behavioral landmarks occurring during courtship. genetic analysis was conducted using reciprocal f1 hybrids of sonora and baja strains to examine inheritance patterns of the responsible co ... | 1990 | 2256893 |
| courtship behavior and control of reproductive isolation in drosophila mojavensis. | | 1989 | 28564202 |
| male hybrid sterility in drosophila: interactions between autosomes and sex chromosomes in crosses of d. mojavensis and d. arizonensis. | by backcrossing hybrids from the cross drosophila mojavensis female × drosophila arizonensis male to both parental species we show that several interspecific combinations of autosomes with one or the other sex chromosome (x or y) result in sperm abnormalities. two of these incompatibilities will cause the same type of nonreciprocal f1 male sterility that is observed in this pair of species, but the possibility of an additional incompatibility that would have the same result, e.g., an incompatibi ... | 1988 | 28581068 |
| location of an autosomal factor causing sterility in drosophila mojavensis males carrying the drosophila arizonensis y chromosome. | drosophila mojavensis males whose y chromosome is replaced by the y of d. arizonensis, have immotile sperm. sperm motility is restored if one member of the fourth autosome pair is also replaced by an arizonensis homologue. we present evidence that the effect of the fourth chromosome is due to a single mendelian factor and map this factor relative to the two markers available for this chromosome. this is an essential first step towards understanding the nature of the incompatibility between the a ... | 1988 | 3366631 |
| selection for sexual isolation between geographic forms of drosophila mojavensis. ii. effects of selection of mating preference and propensity. | | 1987 | 28563619 |
| purification and characterization of a carboxylesterase from the intestine of the nematode caenorhabditis elegans. | the major intestinal esterase from the nematode caenorhabditis elegans has been purified to essential homogeneity. starting from whole worms, the overall purification is 9000-fold with a 10% recovery of activity. the esterase is a single polypeptide chain of mr 60,000 and is stoichiometrically inhibited by organophosphates. substrate preferences and inhibition patterns classify the enzyme as a carboxylesterase (ec 3.1.1.1), but the physiological function is unknown. the sequence of 13 amino acid ... | 1987 | 3651439 |
| sensitivity to larval density in populations of drosophila mojavensis: influences of host plant variation on components of fitness. | chromosomally polymorphic populations of drosophila mojavensis from baja california feed and breed on agria cactus, stenocereus gummosus; whereas, monomorphic arizona populations are associated exclusively with organ pipe cactus, s. thurberi. the effects of this host plant shift in expanding the kinds of feeding and breeding sites were assessed by manipulating larval density and recording differences in egg to adult development time and viability, and adult thorax size in both populations on art ... | 1987 | 28312984 |
| selection for sexual isolation between geographic forms of drosophila mojavensis. i. interactions between the selected forms. | drosophila mojavensis comprises three geographic forms occurring in the united states, the baja california peninsula, and mainland mexico. peninsular and mainland forms were selected for increased sexual isolation from each other, while controls were maintained with maximum outbreeding. response to selection was highly asymmetrical in that isolation was very high between selected peninsular males and mainland females, but nonexistent between selected mainland males and peninsular females. the he ... | 1987 | 28563762 |
| the genetics of asymmetrical male sterility in drosophila mojavensis and drosophila arizonensis hybrids: interactions between the y-chromosome and autosomes. | crosses between drosophila mojavensis and d. arizonensis produce fertile females, but the males from the cross ♂ d. mojavensis × ♀ d. arizonensis are sterile. the chromosomal basis of sperm immotility was studied in these hybrids. interspecific crossing-over was avoided by crossing hybrid males to pure-species females, and chromosomal identification in backcross progeny was possible by means of electrophoretic markers. the main findings are as follows. the y-chromosome and two autosomes are invo ... | 1986 | 28563497 |
| structural comparison of two esterases from drosophila mojavensis isolated by immunoaffinity chromatography. | antibodies raised against esterase-4 and esterase-5 from drosophila mojavensis were coupled to protein a-sepharose cl-4b to prepare high-efficiency immunomatrices used for their purification. final purification was achieved by anion-exchange h.p.l.c., in the case of esterase-5 followed by gel-filtration h.p.l.c. the resultant esterase preparations were homogeneous, as judged by gel-filtration h.p.l.c., sds/polyacrylamide-gel electrophoresis and non-denaturing gel electrophoresis. esterase-4 and ... | 1986 | 3800957 |
| differences in specificity and catalytic efficiency between allozymes of esterase-4 from drosophila mojavensis. | a more than 10-fold difference in the specificity and catalytic efficiency for 1-naphthyl esters was measured between two allozymes of esterase-4 from drosophila mojavensis. this difference is mainly caused by a difference in the affinity for the 1-naphthyl esters. the amino acid compositions of the allozymes are not significantly different, which means that the difference in primary structure is small. small differences in primary structure generally do not result in such a large increase in ca ... | 1986 | 3444410 |
| molecular genetic characterization of a locus that contains duplicate adh genes in drosophila mojavensis and related species. | drosophila mojavensis and other species of the mulleri subgroup contain a duplicate gene encoding the enzyme alcohol dehydrogenase (adh). studies on the genetic relationship of the two genes using electrophoretic variants show them to be closely linked. we have cloned a 13.5-kb fragment of d. mojavensis dna into the lambda vector, charon 30. this fragment contains both adh genes separated by approximately 2 kb of dna. the clone hybridized to a single position on chromosome 3 in d. mojavensis fol ... | 1986 | 3000866 |