Effect of wave of the ovulatory follicle and concentration of progesterone during follicular growth on gene expression associated with conceptus development in dairy cows

• Grant number: 09/53617-0
• Support Opportunities: Scholarships abroad - Research
• Start date: December 15, 2010
• End date: February 16, 2011
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: José Luiz Moraes Vasconcelos
• Grantee: José Luiz Moraes Vasconcelos
• Host Investigator: José Eduardo Portela Santos
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States

Abstract

Hypotheses: The first hypothesis of the present study is that cows induced to ovulate the dominant follicle of the first wave experience premature down regulation of progesterone receptors followed by the up regulation of oxytocin receptors in the uterus during the subsequent estrous cycle. It is also hypothesized that this effect would be reversed by the supplementation with progesterone during the development of the ovulatory follicle. A second hypothesis is that cows induced to ovulate the follicle of the second wave and cows supplemented with progesterone during the development of the ovulatory follicle will have higher uterine expression of alucose transporters, UTMP, FGF-2 and FGF-10. A third hypothesis is that cows induced to ovulate the dominant follicle of the second wave and cows supplemented with progesterone during the development of the ovulatory follicle will have longer conceptuses and greater uterine concentrations of IFN-T 16 d after TAI. Furthermore, trophoblastic expression of glucose transporters and enzymes associated with glycolysis, uterine expression of glucose transporters, UTMP, FGF-2 and FGF-10 will be higher in cows induced to ovulate the dominant follicle of the second wave and in cows supplemented with progesterone during the development of the ovulatory follicle. Objectives: Objectives are to quantify the mRNA for oxytocin and progesterone receptors, UTMP, FGF-2 and FGF-10 and glucose transporters in uterine biopsies collected at d 7, 12 and 16 of the estrous cycle; measure conceptus length and concentration of IFN-T in uterine flush; finally to quantify the mRNA for glucose transporters, UTMP, FGF-2 and FGF-10 in the uterus of pregnant cows, mRNA for glucose transporters, HX, PFK-1 and IFN-T in the trophoblast at d 16 post-AI. (AU)