MOLECULAR-CLONING OF CDNA-ENCODING 2 TYPES OF PITUITARY GONADOTROPIN ALPHA-SUBUNIT FROM THE GOLDFISH, CARASSIUS-AURATUS

Two types of cDNA encoding the alpha subunit of pituitary gonadotropin (GTH) were cloned by polymerase chain reaction (PCR) for goldfish pit uitary cDNA library. The goldfish GTH-alpha subunit cDNAs, designated as alpha 1 and alpha 2, encode 117 and 118 amino acids, respectively, including a 23-amino-acid signal peptide. These two types of cDNAs sho wed high homology in nucleotide and amino acid sequence, but deletion of a triplet nucleotides was present in alpha. Deduced amino acid sequ ences represented differences in four residues between alpha 1 and alp ha 2 subunits. Analyses of goldfish genomic DNA revealed that each ind ividual goldfish possesses two distinct genes relevant to GTH-alpha 1 and -alpha 2 subunits. Results of reverse transcriptase-PCR analysis s uggest that these two GTH-alpha subunit genes are expressed at differe nt levels without relation to sex and gonadal maturity. (C) 1997 Acade mic Press.