Effect of sperm traits on bovine in vitro production

Author(s)

Adriano Felipe Perez Siqueira

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2016-05-31

Examining board members

Mayra Elena Ortiz D'Avila Assumpção; Andréa Cristina Basso; Ricardo Pimenta Bertolla; Eneiva Carla Carvalho Celeghini; Marcilio Nichi

• Advisor: Mayra Elena Ortiz D'Avila Assumpção

Abstract

In vitro production (IVP) of bovine embryos is an important technology of animal reproduction. This technology is applied on research and livestock, with economic highlights, however IVP efficiency could be higher, and can be influenced by male effects. Until now, sperm evaluations had failed to determine these male effects, even using advanced technologies such as large mix of fluorescent probes by flow cytometry analysis, which evaluates a large number of sperm cells and traits simultaneously. Then, the aim of this study was to determine the effect of sperm traits (motility before and after Percoll® selection, plasma membrane and acrosome integrity, high mitochondrial membrane potential, and chromatin structure) on IVP rates. Effect of each trait was enriched to evaluate the individual trait effect (differences between groups of bulls exclusively for the enriched trait, while others traits was homogenous). Combined effect of traits was also evaluated (differences between groups of bulls, and groups of batches from same bulls, for all traits simultaneously, generating a sperm profile). Enriched and combined effects were evaluated on cleavage, blastocyst and embryo development (blastocyst/cleavage) rates. Results showed that motility before Percoll® selection, acrosome integrity, and high mitochondrial membrane enriched effects had negative impact on blastocyst and embryo development rates. Motility after Percoll® selection, plasma membrane integrity, chromatin structure, and combined effects were not significant on IVP rates. We can conclude that controversially, some sperm traits could have a negative effect on IVP outcomes, thereafter sperm traits physiology and interactions with in vitro systems must be better understood to enhance in vitro fertilization conditions, increasing IVP yields. (AU)

• FAPESP's process: 13/07940-9 - Effects of sperm factors on in vitro embryo production and embryo quality in bovine
• Grantee: Adriano Felipe Perez Siqueira
• Support Opportunities: Scholarships in Brazil - Doctorate