Proteomics evaluation of the follicular fluid of Holstein cows under heat stress

• Grant number: 14/21257-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): September 01, 2015
• Effective date (End): August 31, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: João Carlos Pinheiro Ferreira
• Grantee: Rodrigo de Andrade Ferrazza
• Supervisor: Peter David Eckersall
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Research place: University of Glasgow, Scotland
• Associated to the scholarship: 13/20083-8 - 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, BP.DR

Abstract

The reduced fertility associated with summer is a multi-factorial problem. The hyperthermia can affect cellular function in various tissues of the female reproductive tract. Dairy producers might alter their reproductive program to cope with the negative effects of heat stress. This proposal will aim to study the protein expression of follicular fluid of cows undergoing to heat stress condition. For this, 24 non-lactating Holstein cows will be synchronized by Ovsynch® protocol. From the day of ovulation (d2), the cows will be contemporaneously and randomly assigned to thermo neutral (TN; n=12) or heat stress (HS; n=12) treatments. The temperature and humidity of the climate chamber will be 24°C and 60% to TN and 38°C and 60% to HS. Trans-rectal ultrasound of all ovarian structures will be performed twice day for a single operator to characterize the dynamics and follicular deviation. The follicular fluid of the two largest follicles will be punctured guided by ultrasound in the moments of the deviation and after acquisition of ovulatory capacity. An aliquot of the follicular fluid will be designated to measure the concentrations of progesterone and estrogen by radioimmunoassay. The total protein concentration will be determined by the bicinchoninic acid method. The total proteins will be analyzed by 2D electrophoresis in polyacrylamide gels and after by mass spectrometry. For clustering of homologous proteins will be used computational techniques. For statistical analysis will be used the variables follicular diameter, estradiol and progesterone concentrations in follicular fluid, and integrated optical density of differential proteins. The data will be analyzed using ANOVA and the differences between averages will be obtained using Fischer's LSD test. Statistical difference will be considered when P<0.05 and trend when P<0.10. The findings from proteomics will provide information for better understanding of the molecular mechanisms involved in folliculogenesis that will allow greater control on the reproductive function and new approaches in the infertility treatment caused by heat stress. Furthermore, it may work as basis of tools to better exploring the reproductive potential of female cattle and obtaining better results in the use of reproductive biotechnologies. (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)