Gene expression profiles of estrogen receptors α and β in the fetal bovine hypothalamus and immunohistochemical characterization during development

Abstract

Steroid hormones intervene in the structural and functional regulation of neuronal processes during development and thus determine brain differentiation. The effects of estrogens are mediated by two transcription factors, namely estrogen receptor α (ER-α) and estrogen receptor β (ER-β), that regulate the expression of target genes through their binding to specific DNA target sequences. We describe the mRNA expression of ER-α and ER-β in the hypothalamus of developing male and female bovines as revealed by quantitative real-time polymerase chain reaction, and the distribution of the two ERs in hypothalamic sections of all fetal stages as shown by immunohistochemistry. The expression profiles of the mRNAs of both ERs are mutually correlated throughout the gestation period, and their levels increase significantly in the last stages of gestation. No sexual differences in the mRNA expression of either ER-α or ER-β have been found in our fetal specimens. The use of specific antisera against ER-α and ER-β has allowed us to characterize and confirm the distribution of these receptors in the hypothalami of all fetal stages considered. Our results offer detailed information concerning the distribution of ER-α and ER-β in the developing bovine hypothalamus and provide additional insights into the processes involved in the hypothalamic development of a mammal with a long gestation and a highly gyrencephalic brain.

Molecular cloning of ESR2 and gene expression analysis of ESR1 and ESR2 in the pituitary gland of the Chinese alligator ( Alligator sinensis ) during female reproductive cycle

“…However, in female alligators, the mRNA expression level of ESR1 was higher than that of ESR2 in the hypothalamus and liver, which was consistent with the previous reports in the cod (Nagasawa et al, 2014), Italian wall lizard (Verderame and Limatola, 2010), leopard gecko (Endo et al, 2008) and bovine (Panin et al, 2015).…”

The bovine anterior hypothalamus: Characterization of the vasopressin–oxytocin containing nucleus and changes in relation to sexual differentiation

“…A recent paper showed that estrogens exposure exerts a trophic effect on developing bovine granular neurons (Montelli, Suman, Corain, Cozzi, & Peruffo, ). Previous work on estrogen receptors α and β in Cetartiodactyla (including the ovine and the bovine) (Panin, Corain, Montelli, Cozzi, & Peruffo, ; Peruffo, Buson, et al, ; Schaub, Gersting, Keller‐Wood, & Wood, ), suggest that, in freemartins, the brain of the female twin exposed to male androgens undergoes a partial masculinization either through aromatization into estrogens and activation of ER‐α and ER‐β (Kudwa, Michopoulos, Gatewood, & Rissman, ; Roselli, Liu, & Hurn, ), or via the direct effect of androgens on androgen receptors.…”

Sexually Diergic Trophic Effects of Estradiol Exposure on Developing Bovine Cerebellar Granule Cells

“…Previous studies performed in our laboratories developed an in vitro model based on primary cell cultures of the fetal bovine brain [53] and subsequently characterized the expression profiles of the enzyme aromatase P450 and ERs in the fetal bovine hypothalamic area and then in the cerebral cortex region during ontogenesis [26,49,74]. The present study presents a protocol to perform primary cultures of granule cells from the cerebellum of bovine fetuses.…”

“…Our previous studies performed on the fetal bovine hypothalamus and frontal cortex indicated that the patterns of expression of both ERs are strongly correlated during pregnancy and increase in the last stage of gestation [26,74]. Intriguingly, it has been found that in the most malignant brain tumor MBs that arise from cerebellar granule precursors, physiological concentrations of the E2 or the ER-β-selective agonist dose-dependently increased tumor growth [114].…”