In vivo study of the factors involved in the establishment of follicular dominance and atresia in Holstein cows and the effect of heat stress on these phenomena

• Grant number: 13/20083-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2014
• End date: December 31, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: João Carlos Pinheiro Ferreira
• Grantee: Rodrigo de Andrade Ferrazza
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated scholarship(s): 14/21257-2 - Proteomics evaluation of the follicular fluid of Holstein cows under heat stress, BE.EP.DR

Abstract

The profile of gene expression of follicles reflects its status of development. After the period of divergence dominant follicle goes through a differentiation process, especially in granulosa cell layer. This process is characterized by an increase in mitotic and steroidogenic capacity of the dominant follicle. However, in heat stress environment the follicular development occurs abnormally, being characterized by non establishment of follicular dominance, continued growth of other follicles, low estradiol concentration in follicular fluid and suppression of ovulatory capacity. Within this context, the first experiment is proposed with the aim to characterize the in vivo dynamics of gene expression involved in follicular development in Holstein cows at key-moments of the follicular wave (pre-deviation, deviation, after acquisition of ovulatory capacity and after induced ovulatory LH peak), while the goal of the second experiment will be evaluate the effects of heat stress on gene expression in the moments of the deviation and after acquisition of ovulatory capacity. By the technique of quantitative PCR (qPCR) will be studied, specifically, genes encoding gonadotropin receptors (LHR), steroidogenic enzymes (3²HSD and 17²HSD), components of renin-angiotensin system (ACE (P) and RR AGTR2), extracellular matrix remodeling (SerpinE2), cell proliferation (CiclinaD2), protection against apoptosis (XIAP and GADD45b) and fibroblast growth factors (FGF16, FGF17 and FGF20). Due the huge impact of environmental factors, such as heat stress, on reproductive performance, it is expected that the genes identified in this study provide information about the mechanisms involved in folliculogenesis, allowing, thus, greater control over the reproductive function and new approaches in the infertility treatment in summer. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERRAZZA, RODRIGO DE ANDRADE; MOGOLLON GARCIA, HENRY DAVID; DOS SANTOS SCHMIDT, ELIZABETH MOREIRA; CARMICHAEL, MONIKA MIHM; DE SOUZA, FABIANA FERREIRA; BURCHMORE, RICHARD; SARTORI, ROBERTO; ECKERSALL, PETER DAVID; PINHEIRO FERREIRA, JOAO CARLOS. Quantitative proteomic profiling of bovine follicular fluid during follicle development. BIOLOGY OF REPRODUCTION, v. 97, n. 6, p. 835-849, DEC 2017. (12/18297-7, 13/20083-8, 14/21257-2)

FERRAZZA, RODRIGO DE ANDRADE; MOGOLLON GARCIA, HENRY DAVID; VALLEJO ARISTIZABAL, VIVIANA HELENA; NOGUEIRA, CAMILLA DE SOUZA; VERISSIMO, CECILIA JOSE; SARTORI, JOSE ROBERTO; SARTORI, ROBERTO; PINHEIRO FERREIR, JOAO CARLOS. Thermoregulatory responses of Holstein cows exposed to experimentally induced heat stress. Journal of Thermal Biology, v. 66, p. 68-80, MAY 2017. (12/18297-7, 13/20083-8)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

FERRAZZA, Rodrigo de Andrade. Physiological and reproductive aspects of exposure of dairy cows to heat stress. 2016. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu Botucatu.