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ARS Home » Northeast Area » Leetown, West Virginia » Cool and Cold Water Aquaculture Research » Research » Publications at this Location » Publication #183460
Title: INTRAOVARIAN REGULATORS OF FOLLICULOGENESIS IN RAINBOW TROUT:MRNA EXPRESSION OF TRANSFORMING GROWTH FACTOR-BETA SUPERFAMILY MEMBERS

Author
item Lankford, Scott
item Weber, Gregory - Greg

Submitted to: Comparative Endocrinology International Congress Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/2005
Publication Date: 5/23/2005
Citation: Lankford, S.E., Weber, G.M. 2005. Intraovarian regulators of folliculogenesis in rainbow trout:mrna expression of transforming growth factor-beta superfamily members. Comparative Endocrinology International Congress Abstracts.

Interpretive Summary:

Technical Abstract: The process of folliculogenesis has been extensively studied, but the role of intraovarian regulatory factors in this process is still not well understood. Recently, the roles of both autocrine and paracrine growth factors in mammalian folliculogenesis have received considerable attention, while little is known about these regulators in fishes. We investigated the ovarian mRNA expression of members of the transforming growth factor-&beta (TGF-beta) superfamily [bone morphogenetic proteins (BMP) 4 and 7, growth and differentiation factor 9 (GDF-9), inhibin, and BMP and activin membrane-bound inhibitor (BAMBI)], as well as insulin-like growth factor I & II (IGF-I & II) and IGF binding protein 2 (IGFBP-2), during folliculogenesis in rainbow trout. Five developmental stages of follicles [early pre-vitellogenic (Vg), late pre-Vg, early Vg, mid Vg, and late Vg] were examined by real-time RT-PCR. The expression of BMP-4 and BMP-7 mRNAs are highest in the pre-Vg follicles and appear to decline throughout folliculogenesis. Levels of GDF-9 and BAMBI mRNA were not significantly different across the 5 stages, and inhibin mRNA was only up regulated at the mid Vg stage. The expression levels of IGF-I, IGF-II and IGFBP-2 remain low and stable across the three earliest stages and increase throughout mid and late Vg. In addition, preliminary in vitro studies suggest gonadotropin (hCG) does not alter expression of these transcripts in mid Vg follicles. Together, these data suggest disparate roles for members of the TGF-beta superfamily and IGF members in folliculogenesis of rainbow trout.