Sperm exposure to accessory gland secretions alters the transcriptomic response of the endometrium in cattle

In a recent study from our group, mating to intact, but not vasectomised, bulls modified the endometrial transcriptome, suggesting an important role of sperm in the modulation of the uterine environment in this species. However, it is not clear whether these changes are driven by intrinsic sperm factors, or by factors of accessory gland (AG) origin that bind to sperm at ejaculation. Thus, the aim of the present study was to determine whether ejaculated sperm, which are suspended in the secretions of the AGs, elicit a different endometrial transcriptomic response than epididymal sperm, which have never been exposed to AG factors. To this end, bovine endometrial explants collected from heifers in oestrus were incubated alone (control), or with epididymal or ejaculated sperm. RNA-sequencing revealed 1912 differentially expressed genes (DEGs) between in endometrial explants exposed to epididymal sperm compared with control explants, whereas 115 DEGs genes detected between endometrial explants exposed to ejaculated sperm in comparison to control explants. In both cases, the top pathways associated with these genes included T cell regulation and NF-KB and IL17 signalling. To confirm whether AG factors were directly responsible for the dampening of the endometrial response elicited by ejaculated sperm, endometrial explants were incubated with epididymal sperm previously exposed, or not, to seminal plasma (SP). Exposure to SP abrogated the downregulation of SQSTM1 by epididymal sperm, and partially inhibited the upregulation of MYL4 and CHRM3 and downregulation of SCRIB. These data indicate that factors of AG origin modulate the interaction between sperm and the endometrium in cattle.

Genital anatomy, jaw and radula of Guladentia subtussulcata (Helicoidea, Cepolidae), endemic to western Cuba

This study provides the first data on the genital anatomy, jaw and radula of Guladentia subtussulcata (L. Pfeiffer, 1863). The auxiliary copulatory organ of this species is very peculiar, similar to that of Jeanneretia L. Pfeiffer, 1877, and different from that of other cepolids. It consists of an elongate, pedunculate mucus gland inserted apically on a muscular papilla and an atrial sac, all covered by a sheath. A sheath-like accessory gland is inserted at the base of the atrial sac. Another similarity with Jeanneretia is the presence of a fertilization pouch-spermatheca complex with a single exposed spermatheca. Like Jeanneretia, G. subtussulcata has an oxygnath, highly arched jaw with slight striae over the entire surface and a broad, well-developed median projection. The radula has triangular and monocuspid central and lateral teeth (the central teeth are smaller than the rest). The marginal teeth are multicuspid with the mesocone and ectocones smaller than the endocones. The similar structures of the auxiliary copulatory organ (without dart sac) and spermatheca (simple) strongly suggest that G. subtussulcata and Jeanneretia spp. are closely related. As such, it remains to be decided whether Guladentia Clench & Aguayo, 1951 and Jeanneretia should continue to be treated as separate genera.

Semen parameters in male partners of sub-fertile couples.

Objective: To evaluate the frequency of semen parameters in male partners of in sub-fertile couples. Study Design: Cross-sectional study. Setting: Department of Gynaecology, Bakhtawar Ameen Hospital, Multan. Period: July 2019 to July 2020. Material & Methods: Infertile couples from at least 12 months were selected for study. A team of Gynaecologist, andrologist and endocrinologist assessed the couples. In male partner, general physical examination, endocrine factor, genetic assessment, accessory gland infection and testicular dysfunction were evaluated. Semen sample was sent to laboratory for semen analysis. Results: In a total of 169 sub-fertile couples, the mean age of male and female partner were 37.98±4.54 years and 32.51±3.78 years respectively. Mean duration since marriage was 5.17±4.51 years. Abnormal semen parameters such as azoospermia, oilgo-azoospermia, asthenozoospermia, teratozoospermia and aspermia were noted 21 (12.4%), 26 (15.4%), 48 (28.4%), 18 (10.7%) and 10 (5.9%) subjects respectively. There were 46 (27.2%) subjects with normal semen parameters. Conclusion: Most of the male sub-fertile subjects had asthenozoospermia. More than one fourth of the subjects had normal semen parameters.

Single-nucleus transcriptomes reveal evolutionary and functional properties of cell types in the Drosophila accessory gland

Many traits responsible for male reproduction evolve quickly, including gene expression phenotypes in germline and somatic male reproductive tissues. Rapid male evolution in polyandrous species is thought to be driven by competition among males for fertilizations and conflicts between male and female fitness interests that manifest in post-copulatory phenotypes. In Drosophila, seminal fluid proteins secreted by three major cell types of the male accessory gland and ejaculatory duct are required for female sperm storage and use, and influence female post-copulatory traits. Recent work has shown that these cell types have overlapping but distinct effects on female post-copulatory biology, yet relatively little is known about their evolutionary properties. Here we use single-nucleus RNA-Seq of the accessory gland and ejaculatory duct from Drosophila melanogaster and two closely related species to comprehensively describe the cell diversity of these tissues and their transcriptome evolution for the first time. We find that seminal fluid transcripts are strongly partitioned across the major cell types, and expression of many other genes additionally define each cell type. We also report previously undocumented diversity in main cells. Transcriptome divergence was found to be heterogeneous across cell types and lineages, revealing a complex evolutionary process. Furthermore, protein adaptation varied across cell types, with potential consequences for our understanding of selection on male post-copulatory traits.

Induction and inhibition of Drosophila X chromosome gene expression are both impeded by the dosage compensation complex

Sex chromosome gene content frequently differs from that of the autosomes, a phenomenon that can be informative of the effects of chromatin environment, sex-specific selection, recombination, and ploidy on genome evolution. For example, the Drosophila X chromosome is depauperate in genes with male-biased expression or limited expression in specific tissues—in particular those expressed in the accessory gland of the male reproductive tract. Multiple hypotheses have been put forth to explain the unique gene content of the X chromosome, including selection against male-beneficial X-linked alleles, expression limits imposed by the haploid dosage of the X in males, and interference by the dosage compensation complex (DCC) on expression in males. Here, we investigate these hypotheses by examining differential gene expression in Drosophila melanogaster following several treatments known to have widespread transcriptomic effects: bacterial infection, viral infection, and abiotic stress. We found that genes that are induced (up-regulated) by these biotic and abiotic treatments are frequently under-represented on the X chromosome, but so are those that are repressed (down-regulated) following treatment. We further show that whether a gene is bound by the DCC in males can largely explain the paucity of both up- and down-regulated genes on the X chromosome. Specifically, genes that are bound by the DCC are unlikely to be up- or down-regulated after treatment. Moreover, genes that are closer to a high-affinity site where the DCC is thought to initiate binding to the X chromosome experience a smaller change in expression following treatment. This relationship, however, could partially be explained by a correlation between differential expression and breadth of expression across tissues. Nonetheless, our results suggest that DCC binding, or the associated chromatin modifications, inhibit both up- and down-regulation of X chromosome gene expression within specific contexts. This effect could explain why the Drosophila X chromosome is depauperate in genes with tissue-specific expression, in addition to the paucity of X-linked genes differentially expressed after biotic or abiotic treatments. We propose multiple possible mechanisms of action for the effect, including a role of Males absent on the first (Mof), a component of the DCC, as a dampener of gene expression variance in both males and females.

Population biology of accessory gland-expressed de novo genes in Drosophila melanogaster

Early work on de novo gene discovery in Drosophila was consistent with the idea that many such genes have male-biased patterns of expression, including a large number expressed in the testis. However, there has been little formal analysis of variation in the abundance and properties of de novo genes expressed in different tissues. Here we investigate the population biology of recently evolved de novo genes expressed in the D. melanogaster accessory gland, a somatic male tissue that plays an important role in male and female fertility and the post mating response of females, using the same collection of inbred lines used previously to identify testis-expressed de novo genes, thus allowing for direct cross tissue comparisons of these genes in two tissues of male reproduction. Using RNA-seq data we identify candidate de novo genes located in annotated intergenic and intronic sequence and determine the properties of these genes including chromosomal location, expression, abundance, and coding capacity. Generally, we find major differences between the tissues in terms of gene abundance and expression, though other properties such as transcript length and chromosomal distribution are more similar. We also explore differences between regulatory mechanisms of de novo genes in the two tissues and how such differences may interact with selection to produce differences in D. melanogaster de novo genes expressed in the two tissues.

Beyond Sperm and Male Accessory Gland Proteins: Exploring Insect Reproductive Metabolomes

Insect seminal fluid, the non-sperm component of the ejaculate, comprises a variegated set of molecules, including, but not limited to, lipids, proteins, carbohydrates, salts, hormones, nucleic acids, and vitamins. The identity and functional role of seminal fluid proteins (SFPs) have been widely investigated, in multiple species. However, most of the other small molecules in insect ejaculates remain uncharacterized. Metabolomics is currently adopted to deepen our understanding of complex biological processes and in the last 15years has been applied to answer different physiological questions. Technological advances in high-throughput methods for metabolite identification such as mass spectrometry and nuclear magnetic resonance (NMR) are now coupled to an expanded bioinformatics toolbox for large-scale data analysis. These improvements allow for the processing of smaller-sized samples and for the identification of hundreds to thousands of metabolites, not only in Drosophila melanogaster but also in disease vectors, animal, and agricultural pests. In this review, we provide an overview of the studies that adopted metabolomics-based approaches in insects, with a particular focus on the reproductive tract (RT) of both sexes and the ejaculate. Progress in the field of metabolomics will contribute not only to achieve a deeper understanding of the composition of insect ejaculates and how they are affected by endogenous and exogenous factors, but also to provide increasingly powerful tools to decipher the identity and molecular interactions between males and females during and after mating.

The Interplay Between Prostate Cancer Genomics, Metabolism, and the Epigenome: Perspectives and Future Prospects

Prostate cancer is a high-incidence cancer, often detected late in life. The prostate gland is an accessory gland that secretes citrate; an impaired citrate secretion reflects imbalances in the activity of enzymes in the TCA Cycle in mitochondria. Profiling studies on prostate tumours have identified significant metabolite, proteomic, and transcriptional modulations with an increased mitochondrial metabolic activity associated with localised prostate cancer. Here, we focus on the androgen receptor, c-Myc, phosphatase and tensin Homolog deleted on chromosome 10 (PTEN), and p53 as amongst the best-characterised genomic drivers of prostate cancer implicated in metabolic dysregulation and prostate cancer progression. We outline their impact on metabolic function before discussing how this may affect metabolite pools and in turn chromatin structure and the epigenome. We reflect on some recent literature indicating that mitochondrial mutations and OGlcNAcylation may also contribute to this crosstalk. Finally, we discuss the technological challenges of assessing crosstalk given the significant differences in the spatial sensitivity and throughput of genomic and metabolomic profiling approaches.

Drosophila Accessory Gland: A Complementary In Vivo Model to Bring New Insight to Prostate Cancer

Prostate cancer is the most common cancer in aging men. Despite recent progress, there are still few effective treatments to cure its aggressive and metastatic stages. A better understanding of the molecular mechanisms driving disease initiation and progression appears essential to support the development of more efficient therapies and improve patient care. To do so, multiple research models, such as cell culture and mouse models, have been developed over the years and have improved our comprehension of the biology of the disease. Recently, a new model has been added with the use of the Drosophila accessory gland. With a high level of conservation of major signaling pathways implicated in human disease, this functional equivalent of the prostate represents a powerful, inexpensive, and rapid in vivo model to study epithelial carcinogenesis. The purpose of this review is to quickly overview the existing prostate cancer models, including their strengths and limitations. In particular, we discuss how the Drosophila accessory gland can be integrated as a convenient complementary model by bringing new understanding in the mechanisms driving prostate epithelial tumorigenesis, from initiation to metastatic formation.

Female accessory gland fluid promotes sperm survival in yellow dung flies

Female and male reproductive traits co-evolve through pre- and post-copulatory sexual selection and sexual conflict. Although males typically transfer many sperm during copulation, only a small proportion reach the fertilization site because females often actively or passively reduce sperm number in their reproductive tract. Males may transfer accessory substances to protect their ejaculates against female selective processes, which benefits males but can harm females. In turn, females may use accessory gland fluids to control paternity or sperm storage. Female yellow dung flies (Scathophaga stercoraria) have paired accessory glands that produce fluids involved in fertilization and egg laying. One proposed function for these fluids is spermicide. Alternatively, female accessory gland fluid may help keep sperm alive to avoid fertilization failure or encourage sperm competition. Using yellow dung flies, we investigated the interaction of female accessory gland fluid with sperm in vitro. Significantly more sperm remained alive when exposed to accessory gland fluid compared to buffer only (63% vs. 44%). We conclude that female accessory gland fluid in yellow dung flies can help nourish rather than kill male sperm, although selective nourishment of sperm is as consistent with cryptic female choice as is selective spermicide.