Epididymis-spermatozoa interactions in heat stress conditions: effects on paternal contribution to embryo development

• Grant number: 19/23685-5
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2020
• Effective date (End): July 31, 2022
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal researcher: Felipe Perecin
• Grantee: Maíra Bianchi Rodrigues Alves
• Home Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

While morphological and functional sperm attributes are associated with semen quality and male fertility potential, sperm molecular features have recently been acknowledged as determinant for those factors. In that regards, sperm convey RNA molecules, mainly ncRNAs (non-coding RNAs), which are related with early embryonic development. Since sperm cells are typically assorted as transcriptionally inert because they display a highly condensed DNA, these cells acquire most of RNA molecules during the transit through the epididymis. This mechanism of communication is mediated thru the extracellular vesicles (epididymosomes) released by the epididymal epithelium. Recently, we have shown that microRNAs, a specific subpopulation of ncRNAs, are altered in extracellular vesicles isolated from seminal plasma of bulls exposed to scrotal heat stress. However, the results of this study were scanty to demonstrate if the molecular content of the epididymal epithelium could also be altered by the heat stress. Additionally, we could not conclude if the altered vesicles could modulate sperm molecular signature and, therefore, impact early embryonic development. Indeed, the effects of heat stress are well described with regards to testicular-spermatozoa interactions and are known to impair sperm quality and male fertilization potential. However, it is not clear the effects of the heat stress in epididymis-spermatozoa interactions mediated by the epididymosomes. Thus, the hypothesis of the present study is that the heat stress triggers molecular changes in the epididymis and in the sperm cells, which are mediated by epididymosomes and promote an impact on early embryonic development. (AU)