HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 79/6/1160    most recent biolreprod.108.067900v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zachos, N. C. Articles by Pepe, G. J. Search for Related Content PubMed PubMed Citation Articles by Zachos, N. C. Articles by Pepe, G. J. Agricola Articles by Zachos, N. C. Articles by Pepe, G. J.

Regulation of Expression of Microvillus Membrane Proteins by Estrogen in Baboon Fetal Ovarian Oocytes¹

Department of Physiological Sciences,³ Eastern Virginia Medical School, Norfolk, Virginia 23501 Departments of Obstetrics/Gynecology/Reproductive Sciences and Physiology,⁴ The Center for Studies in Reproduction, University of Maryland School of Medicine, Baltimore, Maryland 21201

ABSTRACT

We previously demonstrated that the number and height of oocyte microvilli were reduced in baboon fetuses deprived of estrogen in utero and restored to normal in animals supplemented with estradiol. Phosphorylated ezrin and Na⁺/H⁺ exchange regulatory factor 1 (NHERF, now termed SLC9A3R1) link f-actin bundles to the membrane, whereas alpha-actinin cross-links f-actin to form microvilli. Therefore, we determined whether these proteins were expressed in oocytes of the fetal baboon ovary and whether expression and/or localization were altered between mid and late gestation in association with an increase in estrogen and in late gestation in animals in which estrogen was suppressed (>95%) or restored by treatment with an aromatase inhibitor with or without estradiol. Expression of alpha-actinin was low at mid gestation, increased on the surface of oocytes of primordial follicles in late gestation, and was negligible in the ovaries of estrogen-suppressed fetuses and normal in animals treated with estrogen. Ezrin (total and phosphorylated) and SLC9A3R1 expression was localized to the surface of oocytes at mid and late gestation in estrogen-replete baboons and to the cytoplasm in late gestation after estrogen suppression. These results are the first to show that the fetal baboon oocyte expressed ezrin, SLC9A3R1, and alpha-actinin, and that these proteins were localized to the oocyte surface consistent with their role in microvilli development in epithelial cells. The current study also showed that the developmental increase in oocyte expression of alpha-actinin is regulated by estrogen and correlated with the estrogen-dependent increase in oocyte microvilli demonstrated previously. Therefore, we propose that development of oocyte microvilli requires expression of alpha-actinin and that expression of alpha-actinin and localization of ezrin-phosphate and SLC9A3R1 to the oocyte membrane are regulated by estrogen.

baboon, estradiol, estrogen, fetal oocytes, follicular development, microvilli, oocyte development, ovary

¹Supported by the National Institute of Child Health and Human Development/National Institutes of Health through cooperative agreement U54 HD 36207 as part of the Specialized Cooperative Centers Program in Reproduction and Infertility Research.

Correspondence: ²Gerald J. Pepe, Department of Physiological Sciences, Eastern Virginia Medical School, P.O. Box 1980, Norfolk, VA 23501-1980. FAX: 757 446 8444; e-mail: pepegj{at}evms.edu