BOR - Papers in Press, published online ahead of print
October 30, 2002.
Biol Reprod 2002, 10.1095/biolreprod.102.009985
BIOLOGY OF REPRODUCTION 68, 13241332 (2003)
DOI: 10.1095/biolreprod.102.009985
© 2003 by the Society for the Study of Reproduction, Inc.
Cloning and Spatiotemporal Expression of the Follicle-Stimulating Hormone ß Subunit Complementary DNA in the African Catfish (Clarias gariepinus)1
H.F. Vischera,
A.C.C. Tevesa,
J.C.M. Ackermansa,
W. van Dijka,
R.W. Schulz2,a, and
J. Bogerda
a Department of Endocrinology, Utrecht University, 3584 CH Utrecht, The Netherlands
The gene and cDNA encoding a putative follicle-stimulating hormone ß subunit (cfFSHß) from African catfish (Clarias gariepinus) were cloned. Similar to other FSHß genes, the cfFSHß gene consisted of three exons interrupted by two introns. The cfFSHß cDNA coded for a mature protein of 115 amino acids. The 12 cysteines that are required for the typical tertiary folding of glycoprotein hormone ß subunits were positionally conserved in cfFSHß. The cfFSHß mRNA expression was exclusively detected in the pituitary and was detectable before pubertal development was initiated. The cfFSHß transcript levels increased in particular during early stages of puberty and reached constantly high levels after the first appearance of spermatids in the testis. The cfFSHß mRNA-positive cells were localized in the proximal pars distalis. Castration of mature males caused elevated cfFSHß mRNA levels that were decreased by steroid replacement. Previous work indicated that the African catfish is an interesting model to study the regulation of gonadal functions because cfLH is able to activate both the catfish luteinizing hormone receptor (cfLH-R) and follicle-stimulating hormone receptor (cfFSH-R). Because cfFSH purification has failed so far, ongoing studies are directed toward the production of recombinant cfFSH. After all, the developmental and hormonal regulation of cfFSHß transcript levels opens the possibility for physiologically relevant actions of the putative cfFSH, next to the presumptive bifunctionally acting cfLH.
1 This work was supported by grant BD/5139/95 from PRAXIS XXI MCT-Portugal to A.C.C.T.
2 Correspondence: R.W. Schulz, Utrecht University, Faculty of Biology, Department of Endocrinology, Kruyt Building, Room Z-203, Padualaan 8, NL-3584 CH Utrecht, The Netherlands. FAX: 31 30 2532837; r.w.schulz{at}bio.uu.nl
Copyright © 2003 by the Society for the Study of Reproduction.