CLONING AND EXPRESSION ANALYSIS OF GONADOTROPIN-RELEASING HORMONE RECEPTOR, GNRH-R IN CHINESE STURGEON (ACIPENSER SINENSIS)

The Chinese sturgeon (Acipenser sinensis), an endangered and national protected species, is an important resource for sturgeon aquaculture industry. This study cloned the full-length cDNA of the gonadotropin-releasing hormone receptor (GnRH-R) from pituitary cDNA library of a 24 years old female Chinese sturgeon using rapid amplification of cDNA ends (RACE). The nucleotide sequences of AsGnRH-R is 1530 bp in length, containing a 478 bp 5′-untranslated region (UTR), a 473 bp 3′-UTR, and a 579 bp open reading frame (ORF) with a mature peptide of 192 amino acids encompassing 5 putative N-glycosylation sites. Multiple sequence alignment and phylogenetic analysis of the deduced amino acid sequence of AsGnRH-R indicated that the most similar ortholog was red sea bream (Pagrus major) (76%), and that the least similar ortholog was Callorhinchus milii (39%). Real-time quantitative PCR analysis indicated that the AsGnRH-R was expressed in tissues including liver, spleen, kidney, testis, muscle, intestine, and brain with the highest level in the testis.