Progesterone receptor isoforms in ovary of newly-hatched chick after gonadotropin treatment during embryonic development

Abstract

We evaluated by immunohistochemistry the expression of progesterone receptor (PR) isoforms in different cell subpopulations of the ovary of newly-hatched chicks after a treatment with Follicle-stimulating hormone (FSH) or Luteinizing hormone (LH) administered on days 13, 15 and 17 of embryonic development. Two monoclonal antibodies that recognize either both PR isoforms or only PR-B, were used. The results indicate that FSH increased both the total number of cells and the number of PR-immunoreactive ones in all cell subpopulations of the ovary. In all cases, PR-B was the isoform regulated by FSH. In contrast, LH did not modify the number of total cells in any cell subpopulations of the ovary. Besides, LH decreased the number of PR-B immunoreactive interstitial cells, without modifying PR expression in any other cell subpopulations of the ovary. These results reveal differential effects of FSH and LH on PR-expression in cell subpopulations of the ovary of newly hatched chicks treated during embryonic development. We conclude that gonadotropins regulate PR-B isoform in the prefollicular ovary of the chick.