Evaluation of meiotic progression in the in vitro maturation of bovine oocytes supplemented with different doses of oviduto glycoprotein 1 (OVGP1)

• Grant number: 20/08325-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2020
• End date: July 31, 2021
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Sheila Merlo Garcia Firetti
• Grantee: Ananda Silva Coimbra
• Host Institution: Faculdade de Ciências Agrárias. Universidade do Oeste Paulista (UNOESTE). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The development of alternatives to optimize the productivity of the herd is the current challenge for researchers. In vitro embryo production emerges as a main tool that requires viable and quality gametes to be successful. Therefore, this proposal aims to study the quality of in vitro maturation of oocytes with different dosages of supplementation of oviduct glycoprotein 1 (OVGP1), through nuclear progression, of oocytes from ovaries of female slaughterhouses, and to determine the dosage supplementation that indicates greater viability for the in vitro maturation procedure. Supplementation dosages for in vitro maturation of oocytes will be fetal bovine serum (SFB), which will be treatment 1 (T1) or control, bovine serum albumin (BSA), which will be treatment 2 (T2) and the source of alternative to oviduct glycoprotein 1 (OVGP1), with a dose of 1 ng / ml (T3) and (OVGP1) with a dose of 10 ng / ml (T4), composing the experimental groups. The follicles will be aspirated and the oocytes selected in Grade I and II. Five repetitions will be performed, with (n = 75) oocytes recovered for each repetition, with 15 oocytes being evaluated before maturation and the rest will be submitted to maturation in vitro according to the experimental groups, totaling 60 oocytes matured by repetition. Ovaries of bovine females, with indefinite ages, from the slaughterhouse Gold Carne, in the municipality of Regente Feijó, will be used. For analysis of nuclear progression, the oocytes will be denuded, stained with HOECHST (33342, Sigma Co., St. Louis, USA) and individually evaluated under an epifluorescence microscope. The data will be submitted to the Shapiro-Wilk normality test, analyzed using the ANOVA test followed by the Tukey or Chi-square test (X²) at a significance level of 5% according to the normality results. All analyzes will be performed using the computer program Statistical Analysis System for Windows (SAS Inst., Inc., Cary, NC). With this research, it is expected to obtain important results that will add the knowledge of the present study area of optimization of the PIVE technique.