PARENT SESSION
GENE REGULATION AND FUNCTION - A

Tuesday, August 3, 2004
10:30 AM–12:30 PM
Buchanan Courtyard

(386) EXPRESSION AND HORMONAL REGULATION OF PRL1, PC3, NGF1B, AND DGAT IN THE RAT OVARY.

Schmidt, Jonathan¹, de Avila, Jeanene¹, McLean, Derek¹, ¹ Washington State University, Pullman, WA

ABSTRACT- Follicle stimulating hormone (FSH) and leutinizing hormone (LH) act at the ovary to cause follicular development and ovulation. Ovarian response to these hormones leads to induction and suppression of genes affecting diverse cellular functions. Our long-term goal is to identify and characterize FSH regulated genes involved in proliferation and differentiation of cells in the male and female gonads. In the male, previous research with Affymetrix gene chips identified numerous genes involved in proliferation and differentiation regulated by FSH in immature Sertoli cells. The objective of this study was to establish if a subset of FSH regulated genes in Sertoli cells was also hormonally regulated in the ovaries of prepubertal rats treated with FSH (PMSG) and LH (hCG). Four genes involved in cellular proliferation and differentiation were examined: diacylglyceral acyltransferase (DGAT), neuronal growth factor 1B (NGF1B), an antiproliferative gene (PC3), and a protein tyrosine phosphatase (PRL1). Expression of NGF1B, DGAT, and PRL1 was dramatically induced in rat ovaries by 4 hours post PMSG treatment, and returned to control levels by 12 hours post treatment. When rats were treated with hCG, NGF1B, DGAT, and PRL1 expression was induced by 12 hours post treatment. Expression of PC3 was not significantly affected by either PMSG or hCG treatment. Immunohistochemistry analysis of NGF1B protein expression demonstrates an increase of the protein approximately 12-24 hours later than up regulation of gene expression in both PMSG and hCG treated rats. NGF1B protein was observed in the granulosa and theca cells post PMSG treatment and in granulosa, theca, and luteal cells post hCG treatment. These results indicate FSH and LH regulate the expression of DGAT, NGF1B, and PRL1 in the ovaries of rats. To our knowledge, this is the first report of a the use of genomic data of hormonally regulated genes in the male to identify genes hormonally regulated in the ovary that we expect are important in folliculogenesis and luteal function.

KEY WORDS: lh, fsh, ovary, gene expression