Project description:It is now well established that mature mammalian spermatozoa carry a population of mRNA molecules, at least some of which are transferred to the oocyte at fertilisation. However, the function of the sperm transcriptome remains largely unclear. To shed light on the evolutionary conservation of this feature of sperm biology, we analysed highly purified populations of mature sperm from the fruitfly, Drosophila melanogaster. As with mammalian sperm, we found a consistently enriched population of mRNA molecules that are not likely to be derived from contaminating somatic cells or immature sperm. Using tagged transcripts for three of the spermatozoal mRNAs, we demonstrate that they are transferred to the oocyte at fertilisation and can be detected at least until the onset of zygotic gene expression. We find a remarkable conservation in the functional annotations associated with fly and human spermatozoal mRNAs, in particular a highly significant enrichment for transcripts encoding Ribosomal Proteins. The identification of a conserved set of spermatozoal transcripts opens the possibility of using the power of Drosophila genetics to address the function of this enigmatic class of molecules. RNA extracted from three biological replicates of purified sperm (Sperm rep1, Sperm rep2 and Sperm rep3) was used as a template for oligo-dT-primed reverse transcription, amplification, labelling of dye swapped technical replicates and hybridisation to long oligonucleotides microarrays. As a control, RNA from two biological replicates of dissected adult testis plus accessory glands (Testis_rep1, Testis_rep2) was amplified, labelled (dye-swap technical replicate) and hybridised to similar arrays. To help with the spot-finding of the arrays genomic DNA was co-hybridised in some cases (this genomic DNA data was excluded from further analysis). Genes with an intensity level below 200 in at least one channel across the Sperm or Testis set were removed (5579 transcripts present in all three sperm replicates, 5358 transcripts from the testis/accessory gland samples and 4295 transcripts common to both data sets). Then the quantile normalisation was independently applied to the Sperm replicate samples and Testis replicates.
Project description:Here we directly test the hypothesis that PCSS results in rapid evolution of the entire male accessory gland proteome and protein networks by taking a system-level approach, combining divergent experimental evolution of PCSS in Drosophila pseudoobscura (Dpse), high resolution mass spectrometry (MS) and proteomic discovery, bioinformatics and population genetic analyses.
Project description:The Drosophila melanogaster male accessory gland (AG) is crucial for reproductive success, producing seminal fluid proteins that impact female post-mating behavior and physiology. To understand the regulatory networks governing accessory gland function, we conducted a bulk RNA sequencing (RNA-Seq) study to analyze the effects of overexpressing three key regulatory genes: dMyc, Yorkie (Yki), and the E2F-Dp heterodimer, compared to wild-type (WT) controls. We found upregulated and downregulated genes in each condition compared to controls, affecting immune response, cell cycle, stress response, and reproductive functions. In both Yki constitutively active, E2F+Dp and dMyc, E2F+DP conditions, several genes known to be involved in wound healing and tumorigenic models in flies were upregulated, including JNK signaling targets Ets21C, MMP1, puckered, and Jak/STAT signaling pathway ligands upd2 and upd3. Conversely, accessory gland-specific genes, such as many Accessory Gland Proteins (Acps), and genes involved in fertility, mating behavior, and sperm competition were downregulated. There was a strong overlap between the Yki constitutively active, E2F+Dp and dMyc, E2F+Dp gene expression signatures, converging on genes commonly misregulated in proliferative tumor models in various larval tissues, including imaginal discs and brains. This study provides insights into the molecular mechanisms by which key regulatory genes influence the function and integrity of the Drosophila male accessory gland.
Project description:Here we show that the Drosophila nuclear receptor DHR39 is necessary for male reproduction and acts as a global regulator of accessory gland gene expression. Mutants for the DHR39 transcription factor are sterile, with the majority of accessory gland genes expressed at reduced levels. Specific depletion of DHR39 within the accessory gland is sufficient to reduce male fecundity and accessory gland gene expression. Restoration of DHR39 in the accessory gland of DHR39 mutants rescues this sterility and transcriptional reduction. We conclude that DHR39 is a key regulator of most accessory gland genes, including ovulin and sex peptide, and is necessary for male fertility.