Comparative study of the hormonal profile, of folliculogenesis, oocyte quality and meiotic competence of oocytes in vitro in female dogs in three different periods of anestrus stage (beginning, middle and end).

• Grant number: 11/07446-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2011
• End date: June 30, 2014
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Wilter Ricardo Russiano Vicente
• Grantee: Eliandra Antonia Pires Buttler
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

In canids, the use of assisted reproduction techniques has the goal of genome preservation in endangered wild canids. However the meiotic competence of canine oocytes submitted to in vitro culture has been delaying the development of reproductive biotechnologies in this specie. According to researchers the low efficiency of IVM can be related to the poor knowledge of peculiarities in the bitch reproductive physiology. Thus, the aim of the present study is to enhance de knowledge of the reproductive events that occur during the anestrous phase, comparing the hormonal profile, follicular development and quality and meiotic competence of canine oocytes. The oocyte will be evaluated in three different periods of the anestrous in order to verify if during this phase exists a determinate period that the oocytes presents higher quality and greater meiotic competence. Fifteen anestrous bitches, aging to 1 to 7 years will be clustered in three groups: A1 (beginning of anestrous), A2 (middle of anestrous) and A3(end of anestrous). To characterize the hormonal profile, blood samples will be collected to determine serum FSH, LH, IGF and estrogen previously to the ovaryhisterectomy (OH). After the surgical procedure, the ovaries will be divided in two parts, one for histological analyses and the other for oocytes acquirement. The oocyte will be cultured for 72 hours in five different maturation media: Medium I (TCM199 + FSH + IGF during 48 hours and TCM199 + hCG + P4 + E2 for additional 24 hours), Medium II (TCM199 + FSH for 48 hours and TCM199 + hCG + P4 + E2 for additional 24 hours), Medium III (TCM199 + FSH + IGF + hCG + P4 + E2 during 72 hours), Medium IV (TCM199 + FSH + hCG + P4 + E2 during 72 hours), Medium V (TCM199 for 48 hours and TCM199 + hCG + P4 + E2 for additional 24 hours). The ultrastructural analisys of the canine oocytes will be evaluated before and after 72 hours of in vitro culture by scanning and transmission electronic microscopy and by Lucifer Yellow staining.