Localization of oestrogen receptors within various bovine ovarian cell types at different stages of the oestrous cycle.
In the present study oestrogen receptor alpha(ERalpha) and oestrogen receptor beta (ERbeta) mRNA were localized in various ovarian cell types of 23 cows at different stages of the oestrous cycle. ERalpha was detected by immunohistochemistry and the localization of ERbeta mRNA was examined using in situ hybridization. The immunostaining of ERalpha was low in the ovarian follicles, tunica albuginea and surface epithelium, but high in cells of the deep stroma and superficial stroma, which indicates a functional role of ERalpha in the cells surrounding the follicles. In contrast, ERbeta mRNA scores were low to moderate in primordial and primary follicles, and increased with the development of the follicle. ERbeta mRNA scores were higher in cystic follicles than in obliterative follicles. In the corpora lutea and corpora albicantia the scores for ERbeta mRNA were moderate. Furthermore, in the corpora lutea, ERbeta mRNA levels showed cyclic variations and were low during early dioestrus. The correlation between plasma progesterone levels and the score for ER was low and negative in all ovarian cell types. This study demonstrates the predominant role of ERbeta over ERalpha in bovine ovarian structures. Furthermore, the colocalization of both ERbeta mRNA and ERalpha in most cell types suggests possible interactions between both ER subtypes.
D'Haeseleer
M
M
Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. wim.vandenbroeck@ugent.be
Cornillie
P
P
Simoens
P
P
van den Broeck
W
W
D000818:Animals; D002417:Cattle; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D004971:Estrus / Q000378:metabolism*; D005260:Female; D017403:In Situ Hybridization / Q000379:methods / Q000662:veterinary; D010053:Ovary / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis*; D011960:Receptors, Estrogen / Q000235:genetics* / Q000378:metabolism*
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger; D011960:Receptors, Estrogen