Cloning and sequencing of carp and medaka activin subunit genes

Activins are dimeric proteins that belong to the transforming growth factor -beta superfamily. Using the polymerase chain reaction (PCR), we have clone d and sequenced activin beta(A) and beta(B) genes, which encode the mature region of the peptides, from carp and medaka genomic DNA. The carp activin gene that codes for one type of beta(A) and three types of beta(B) was isol ated from carp genomic DNA.(*3) Similarly, the medaka activin gene that cod es for two types of beta(A) and one type of beta(B) was isolated from medak a genomic DNA.(*4) High identities were found to exist between these subuni ts and their mammalian counterparts. The carp beta(A) subunit has 75.5% nuc leotide sequence identity with the human beta(A) subunit and the three carp beta(B) subunits more than 84% with the human beta(B) subunit. The two med aka beta(A) subunits have greater than 73.5% nucleotide sequence identity w ith the human beta(A) subunit, while the medaka beta(B) subunit exhibits 84 % sequence identity with the human beta(B) subunit.