Poster Presentation ESA-SRB-APEG-NZSE 2022

Elucidation of the protein composition of mouse seminal vesicle fluid (#383)

Shannon P Smyth 1 2 , Brett Nixon 1 2 , Amanda L Anderson 1 2 , Heather C Murray 3 4 , Lily A MacDougall 1 2 , Jacinta H Martin 1 2 , Elizabeth G Bromfield 1 2 5 , Sarah A Robertson 6 , David A Skerrett-Byrne 1 2 , John E Schjenken 1 2
  1. Infertility and Reproduction Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
  2. School of Environmental and Life Sciences, College of Engineering, Science and Environment, University of Newcastle, Newcastle, NSW, Australia
  3. Cancer Research Program, Hunter Medical Research Institute, Newcastle, NSW, Australia
  4. School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, NSW, Australia
  5. Department of Biomolecular Health Sciences and Department of Farm and Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
  6. The Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia

The seminal vesicles are an integral male reproductive tract accessory gland whose secretions constitute a major proportion of seminal plasma. Fundamentally, these secretions are responsible for supporting gamete function and promoting reproductive success. Analysis of seminal vesicle fluid composition by proteomics has proven challenging, largely due to the combined features of a protein signature that is dominated by a small subset of highly abundant proteins and the difficulty of solubilising this viscous fluid. As such, publicly available proteomic datasets have only reported a total of 85 mouse seminal vesicle fluid proteins, although compelling evidence suggests greater fluid complexity. To address this limitation, we have established a new proteomics-based method involving the sequential solubilisation of mouse seminal vesicle fluid in guanidine hydrochloride, acetone precipitation and subsequent analysis using label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). This approach facilitated the identification of 126 proteins, a significant improvement (1.48× increase) compared to the previously curated mouse seminal vesicle fluid proteome. Consistent with established roles for these secretions, reproductive and immune functions associated with the regulation of sperm survival and function, as well as modulation of the female immune environment were significantly enriched within our dataset. Notably, 83 of the 126 proteins identified in our dataset were previously undetected in this fluid. These proteins include voltage dependent anion channel 3 (VDAC3), members of the serine protease inhibitor, Kazal-type (SPINK8 and SPINK11) and prostate and testis-expressed (PATE8 and PATE9) families, which may act as novel seminal vesicle fluid mediators that influence sperm function and fertilisation capacity. These new insights into the composition of seminal vesicle fluid are relevant to understanding how events during the peri-conception period affect reproductive outcomes. Overall, the knowledge gained through our study and future applications of this methodology may assist in improving reproductive health and developing novel infertility treatments.