Study of miRNAs profile of boars\' ejaculates with different freezability

Author(s)

Ana Carolina Pedrosa

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2021-05-07

Examining board members

André Furugen Cesar de Andrade; Diego Vilela Alkmin; Janaina Torres Carreira

• Advisor: André Furugen Cesar de Andrade; Juliano Coelho da Silveira

Abstract

Sperm cryopreservation is the most efficient method to preserve semen for the long term in mammals. However, freeze boar semen is still the biggest challenge for the swine industry due to the high cold shock sensitivity of boar sperm cells and the variance of post-thaw results among individuals and ejaculates from the same boar. To solve this problem, we investigate if microRNAs (miRNAs) present in sperm cells and small extracellular vesicles (E.V.s) from seminal plasma of raw boar ejaculates can predict high-quality ejaculates after underwent the freeze-thaw process. Therefore, we collected 27 high-quality ejaculates of 27 boars (one of each) obtained miRNAs samples of sperm cells and E.V.s from raw seminal plasma through centrifugation protocols. After the cryopreservation process, we determined two groups with different freezability considering the analysis post-thaw of structure and sperm functionality (P<0.05): High freezability (H.F.; n=04) and low freezability (L.F.; n=04). That done, we finally investigate the miRNAs profile of sperm cells and E.V.s from seminal plasma in both groups with different freezability. Our main results showed that three miRNAs were differently abundant in L.F. ejaculates, being the ssc-miR-503 found in higher levels in sperm cells. The ssc-miR-130a and ssc-miR-9 most abundant in E.V.s from seminal plasma (P <0.10). Through enrichment analysis, it was possible to verify that these miRNAs could be performing modifications in the development of male germ cells and in the production of energy to spermatozoa to maintain their viability and functionality. Therefore, through this study, we can demonstrate that ssc-miR-503, ssc-miR-130a, and ssc-miR-9 are related to low sperm cryotolerance in boars semen. So those miRNAs can be used as a biomarker to predict their low ability to tolerate the cryopreservation process. (AU)

• FAPESP's process: 18/12500-1 - Study of the miRNAs profile of boars ejaculates with different freezability
• Grantee: Ana Carolina Pedrosa
• Support Opportunities: Scholarships in Brazil - Master