Project description:Postcopulatory sexual selection is recognized as a key driver of reproductive trait evolution, including the machinery required to produce endogenous nuptial gifts. Despite the importance of such gifts, the molecular composition of the non-gametic components of male ejaculates and their interactions with female reproductive tracts remain poorly understood. During mating, male Photinus fireflies transfer to females a spermatophore gift manufactured by multiple reproductive glands. Here we combined transcriptomics of both male and female reproductive glands with proteomics and metabolomics to better understand the synthesis, composition and fate of the spermatophore in the common Eastern firefly, Photinus pyralis. Our transcriptome of male glands revealed up-regulation of proteases that may enhance male fertilization success and activate female immune response. Using bottom-up proteomics we identified 208 functionally annotated proteins that males transfer to the female in their spermatophore. Targeted metabolomic analysis also provided the first evidence that Photinus nuptial gifts contain lucibufagin, a firefly defensive toxin. The reproductive tracts of female fireflies showed increased gene expression for several proteases that may be involved in egg production. This study offers new insights into the molecular composition of male spermatophores, and extends our understanding of how nuptial gifts may mediate postcopulatory interactions between the sexes.
Project description:Despite holding a central role for fertilisation success, reproductive traits often show elevated rates of evolution and diversification. The rapid evolution of seminal fluid proteins (Sfps) within populations is predicted to cause mis-signalling between the male ejaculate and female reproductive tract between populations resulting in postmating prezygotic (PMPZ) isolation. Crosses between populations of Drosophila montana show PMPZ isolation in the form of reduced fertilisation success in both noncompetitive and competitive contexts. Here we test whether male ejaculate proteins deriving from either the accessory glands or the ejaculatory bulb differ between populations using liquid chromatography tandem mass spectrometry. We find more than 150 differentially abundant proteins between populations which may contribute to PMPZ isolation. These proteins include a number of proteases and peptidases, and several orthologs of D. melanogaster Sfps, all known to mediate fertilisation success and which mimic PMPZ isolation phenotypes. Males of one population typically produced greater quantities of Sfps and the strongest PMPZ isolation occurs in this direction. The accessory glands and ejaculatory bulb have different functions and the ejaculatory bulb contributes more to population differences than the accessory glands. Proteins with a secretory signal, but not Sfps, evolve faster than non-secretory proteins although the conservative criteria used to define Sfps may have impaired the ability to identify rapidly evolving proteins. We take advantage of quantitative proteomics data from three Drosophila species to determine shared and unique functional enrichments of Sfps that could be subject to selection between taxa and subsequently mediate PMPZ isolation. Our study provides the first high throughput quantitative proteomic evidence showing divergence of reproductive proteins implicated in the emergence of PMPZ isolation between populations.
Project description:Although the presence of RNA in seminal fluid appears to be a conserved feature of male ejaculates, it is unknown whether this RNA is functional within females. Here, we develop an experimental proteomic method called VASPA (Variant Assisted SILAC Proteomic Analysis) to test the hypothesis that Drosophila male seminal fluid RNA is translated by females. We find evidence for 166 male-derived, female-translated proteins (mdFTPs) in female lower reproductive tracts at six hours postmating, many with predicted functions relevant to reproduction.
Project description:Reproductive traits that influence female remating and competitive fertilization rapidly evolve in response to sexual selection and sexual conflict. One such trait, observed across diverse animal taxa, is the formation of a structural plug inside the female reproductive tract, either during or shortly after mating. In Drosophila melanogaster, male seminal fluid forms a mating plug inside the female bursa, which has been demonstrated to influence sperm entry into storage and latency of female remating. Processing of the plug, including its eventual ejection from the female's reproductive tract, influences the competitive fertilization success of her mates and is mediated by female × male genotypic interactions. However, female contributions to plug formation and processing have received limited attention. Using developmental mutants that lack glandular female reproductive tract tissues, we reveal that these glandular tissues are essential for the mating plug to be ejected. We further use proteomics to demonstrate that female glandular proteins, and especially proteolytic enzymes, contribute to mating plug composition and that the absence of glands has a widespread impact of plug formation and composition. Together, these phenotypic and molecular data resolve molecular mechanisms of important postmating, intersexual interactions and cryptic female choice.
Project description:Male-derived accessory gland proteins (Acps) that are transferred to females during mating have profound effects on female reproductive physiology including increased ovulation, mating inhibition, and effects on sperm utilization and storage. The extreme rates of evolution seen in Acps may be driven by sperm competition and sexual conflict, processes which may ultimately drive complex interactions between female- and male-derived molecules and sperm. However, little is known of how gene expression in female reproductive tissues changes in response to the presence of male molecules and sperm. To characterize this response, we conducted parallel genomic and proteomic analyses of gene expression in the reproductive tract of 3-day-old unmated and mated female Drosophila melanogaster. Using DNA microarrays, we identified 539 transcripts that are differentially expressed in unmated vs. mated females and revealed a striking peak in differential expression at 6 hrs postmating and a marked shift from primarily down-regulated to primarily up-regulated transcripts within 3 hrs after mating. Combining two-dimensional gel electrophoresis and liquid chromatography mass spectrometry analyses, we identified 84 differentially expressed proteins at 3 hrs postmating, including proteins which appeared to undergo post-translational modification. Together, our observations define transcriptional and translational response to mating within the female reproductive tract and suggest a bimodal model of postmating gene expression initially correlated with mating and the final stages of female reproductive tract maturation and later with the declining presence of male reproductive molecules and with sperm maintenance and utilization. Experiment Overall Design: Three-day-old mated and unmated females were dissected to remove the lower reproductive tract (upper uterus, sperm-storage organs, and accessory glands). Mated females were dissected either immediately following mating (0 hr) or at 3, 6, or 24 hrs following the termination of mating. Tracts of 12-40 females of like category were pooled and total RNA extracted via a TRIzol-based protocol. Processing and labeling of transcript was performed by the Molecular Biology Core Facility at the Medical College of Georgia. Arrays from mated females at the different timepoints were compared to unmated females.
Project description:Postcopulatory sexual selection is now widely recognized as a key driver of reproductive trait evolution, including the machinery required to produce endogenous nuptial gifts. Despite the importance of such gifts, molecular composition of the non-gametic components of male ejaculates and their interactions with female reproductive tracts remain poorly understood. . Here we combined transcriptomic studies of both male and female reproductive glands with proteomic and metabolomic approaches to better understand the synthesis, composition and fate of this spermatophore gift in the common Eastern firefly, Photinus pyralis.
Project description:Comparative genomic hybridization was performed to compare levels of gDNA in third instar salivary glands of Drosophila mutants/nulls in the SuUR and orc proteins, compared with 0-2hr diploid embryo gDNA. This illustrates regions of differential replication in the genome.
Project description:We studied the effect of social environment (presence of conspecific males and/or females) and gamma irradiation on gene expression in the male reproductive tract (aedeagus, ejaculatory bulb, 2 bilobed testes and 3 pairs of smaller accessory glands; the two pairs of larger accessory glands were removed) in a full factorial design.
Project description:Organisms were sampled from a field population located in Eastern Central France. Because our focus on proteins involved in reproduction, only sexually mature organisms were chosen by selecting the ones in pre-copulatory mate guarding. We first established a database of nucleic acid-derived protein coding sequences. For this, we extracted total RNAs from four key tissues: the male and female reproductive tissues, the cephalon where several neuroendocrine glands are located and the hepatopancreatic caeca, involved in xenobiotics detoxification and energy acquisition (digestive enzyme secretion, food absorption and nutriment storage). Equal amounts of RNAs from each tissue were pooled together and sequenced in a single run of the Illumina next-generation sequencing approach. The resulting nucleic acid information was used to create a protein database that could be used for proteogenomic identification of proteins. For this, each mRNA contig was systematically translated into the six possible reading frames, thus for considerating all possible putative ORFs. Tandem mass spectrometry data could be assigned with this database. The protein catalogue established from experimental pieces of evidence allows selecting the appropriate reading direction and frame of each protein-coding mRNA contig. We recorded a large dataset on the proteomes from three tissues (reproductive tissues and the cephalon) by resolving each sample by OFFGEL electrophoresis (24 fractions per sample). Each experiment was conducted in triplicates for reproductive tissues and duplicates for the cephalon, resulting in 192 peptide complex mixtures. These samples were analyzed by nanoLC-MS/MS with a high resolution LTQ-Orbitrap XL hybrid mass spectrometer (ThermoFisher). We also focused our attention on the proteome dynamics of the male reproductive tissue analyzed at seven different spermatogenesis stages (pre-copulatory mate guarding, Day 0, Day 1, Day 2, Day 3, Day 4 and Day7) on five biological replicates. Protein extracts from the testis samples were subjected to a short SDS-PAGE electrophoresis in order to get a single polyacrylamide band per proteome. The 35 samples were in-gel trypsic digested and the resulting peptide mixtures were analyzed by nanoLC-MS/MS.
Project description:Purpose: Use of RNAseq to identify crucial genes expressed in the reproductive tract of C. capitata The medfly, Ceratitis capitata continues to pose a major threat to the agricultural sector in almost every continent. Promiscuous female medflies can oviposit up to 1000 eggs throughout their lifetime causing remarkable losses in crop viability. Nowadays, there is an increasing demand for finding new improved solutions to counteract its invasive spreading capacity. To these regards, research that aims in understanding the reproductive biology of fruit fly pests by obtaining its genomic profiling can be of great contribution to this field. In this study we have generated a De-novo assembly of the medfly reproductive tract transcripts. We used Transcriptomics via deep RNA-sequencing to identify the transcripts present in the sex organs (spermatheca, uterus and accessory glands) of sexually matured virgin and 24hr-freshly mated females as well as testes, and male accessory glands of C. capitata. In addition, differential expression changes between virgin and mated females could help elucidate crucial candidate genes that participate in the female physiological response to the male seminal input. Furthermore, in order to ensure pure and significant results of the transcriptomic analysis, we have included a negative control that includes gut and abdominal adipose tissue. The newly annotated genes from this investigation could furthermore contribute to the ongoing field of biological and genetic population control.