ANALYSIS OF THE OVARIAN ESTROGEN RECEPTOR Α AND Β IN COWS GESTATED UNDER HEAT STRESS CONDITIONS.

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

Mar del Plata

Congreso; Reunión Conjunta SAIC SAI SAFIS 2018; 2018

The effects of adverse ambient conditions (number of days withtemperature-humidity index (THI) exceeding the comfort threshold:>72) on dairy cows can affect the reproduction not only in a directway, also in the progeny of the animals that were gestated understress conditions. In fact, the ovarian follicular reserve is establishedduring the first half of the fetal life (0-150 days) and many factorscan affect the future fertility of the offspring. Within these factors,Estrogen Receptors (ER) α and β are the most important regulatorswhich gene expression could be modulated. The aim of this studywas to evaluate the gene and protein expression of ERα and ERβ inpreovulatory follicles of animals gestated under heat stress in differentstages of pregnancy. Holstein cows (n=20) were divided in twogroups: group 1 (cows gestated under heat stress between 0-150days of pregnancy) and group 2 (cows gestated under heat stressbetween 151days-end of pregnancy). Similar levels of ERα and βmRNA were detected by real time PCR, in follicular wall of differentgroups analyzed (p>0.05). For quantitative methylation analysisof the 5´UTR sequences of ERα and β, an AGENA?s MassARRAYplatform was used. No differences were detected for any CpG analyzedfor both receptors (p>0.05). On the other hand, the proteinexpression evaluated by immunohistochemistry show similar levelsof ERα in granulosa and theca interna of preovulatory follicles ofthe groups analyzed (p>0,05) and a higher expression of ERβ ingranulosa and theca cells of preovulatory follicles of cows of Group2 related to Group 1 (p