Analysis of the ovarian estrogen receptor α and β in cows gestated under heat stress conditions

HUBER EMILIA; ORTEGA HUGO HÉCTOR; RODRÍGUEZ FERNANDA MARIEL; NOTARO ULISES; DÍAZ PABLO; SALVETTI NATALIA RAQUEL; RECCE SEBASTIÁN; REY FLORENCIA

Mar del Plata

Congreso; LXIII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica (SAIC), LXVI Reunión anual de la SAI; Reunión anual de la SAFIS; con la participación de la SAV y Asociacion Argentina de Nanomedicinas (NANOMEDAR).; 2018

SAIC

The effects of adverse ambient conditions (number of days with temperature-humidity index (THI) exceeding the comfort threshold: >72) on dairy cows can affect the reproduction not only in a direct way, also in the progeny of the animals that were gestated under stress conditions. In fact, the ovarian follicular reserve is established during the first half of the fetal life (0-150 days) and many factors can affect the future fertility of the offspring. Within these factors, Estrogen Receptors (ER) α and β are the most important regulators which gene expression could be modulated. The aim of this study was to evaluate the gene and protein expression of ERα and ERβ in preovulatory follicles of animals gestated under heat stress in different stages of pregnancy. Holstein cows (n=20) were divided in two groups: group 1 (cows gestated under heat stress between 0-150days of pregnancy) and group 2 (cows gestated under heat stress between 151days-end of pregnancy). Similar levels of ERα and β mRNA were detected by real time PCR, in follicular wall of different groups analyzed (p>0.05). For quantitative methylation analysisof the 5´UTR sequences of ERα and β, an AGENA?s MassARRAY platform was used. No differences were detected for any CpG analyzed for both receptors (p>0.05). On the other hand, the protein expression evaluated by immunohistochemistry show similar levels of ERα in granulosa and theca interna of preovulatory follicles of the groups analyzed (p>0,05) and a higher expression of ERβ in granulosa and theca cells of preovulatory follicles of cows of Group 2 related to Group 1 (p<0.05). These data suggest that changes in the expression of estrogen receptors, mainly ERβ, can lead to analtered response of steroid hormones, and thus contribute to ovarian alterations in animals gestated under heat stress.