Expression of progesterone receptors A and B in the mouse ovary during the estrous cycle.
Progesterone plays a central role in the regulation of ovarian function. The progesterone receptor (PR) has been shown to be essential for ovulation because mice lacking PR fail to ovulate and are infertile. PR is expressed as two isoforms, PRA and PRB, which have been shown to have different functional activities. In this study, we investigated the cellular distribution of PRA and PRB in the ovaries and oviducts of cycling mice using immunohistochemistry with isoform-specific monoclonal antibodies. In the ovary, on the evening of proestrus before ovulation, both the granulosa and theca cells of the preovulatory follicles expressed both PR isoforms. PRA and PRB staining was also observed in the theca cells of preantral and antral follicles, whereas only PRB was observed in the granulosa cells of primary, preantral, and antral follicles and in the corpus luteum. In the oviduct, PRA was the predominant isoform observed, expressed in both the epithelial and stromal cells, whereas PRB was only detected in the epithelial cells. The differences in PRA and PRB localization in the ovary and oviduct may reflect diverse functions for PRA and PRB in reproductive tissues and may have important implications in understanding the mechanisms of progesterone action.
Gava
Natalie
N
Department of Gynecological Oncology, Westmead Hospital, Westmead, New South Wales 2145, Australia. anna_defazio@wmi.usyd.edu.au.
Clarke
Christine L
CL
Byth
Karen
K
Arnett-Mansfield
Rebecca L
RL
deFazio
Anna
A
D000818:Animals; D000911:Antibodies, Monoclonal; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D010053:Ovary / Q000378:metabolism*; D010057:Oviducts / Q000378:metabolism; D011980:Receptors, Progesterone / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D011980:Receptors, Progesterone; C101118:progesterone receptor A; C097314:progesterone receptor B