EVALUATION OF OVARIAN GLUCOCORTICOID RECEPTOR Α EXPRESSION IN COWS GESTATED UNDER HEAT STRESS CONDITIONS

HUBER, E.; NOTARO, U.S.; RECCE, S.; ORTEGA, H. H.; SALVETTI, N. R.; REY, F.; RODRÍGUEZ, F. M.

Mar del Plata

Congreso; Reunión Conjunta SAIC SAI SAFIS 2018; 2018

Adverse ambient conditions (temperature-humidity index (THI) exceedingthe comfort threshold (72) for 3 or more days) on dairy cowscan affect reproduction not only in a direct way, also in the progenyof animals that are gestated under these stress conditions. In fact,the ovarian follicular reserve is established during the first half of thefetal life (0-150 days) and many factors can affect the future fertilityof the offspring. Under stress situations, nervous system triggers asignaling cascade with a final secretion of glucocorticoids (GCs). Itis known that GCs exert actions in the ovary, mainly through the GCreceptor α (GRα). In this study, we evaluated gene expression ofGRα in preovulatory follicles of cows gestated under heat stress indifferent stages of gestation, and epigenetic mechanisms that couldregulate gene expression. Holstein cows (n=20) were divided in twogroups: group 1 (cows gestated under heat stress between 0-150days of gestation) and group 2 (cows gestated under heat stressbetween 151 days-end of gestation). Higher levels of GRα were detectedby Real Time PCR in follicular wall of preovulatory folliclesof group 1 relative to group 2 (p