Through differential screening between oyster families selected for high and low summer survival, we have characterized a new transforming growth factor-beta (TGF-beta) superfamily member. This novel factor, named oyster-gonadal-TGF beta-like (og-TGF beta-like), is synthesized as a 307 amino acid precursor and displays 6 of the 7 characteristic cysteine residues of the C-terminal, mature peptide. Sequence comparison revealed that og-TGF beta-like has a low percentage of identity with other known TGF-beta superfamily members, suggesting that og-TGF beta-like is a derived member of this large superfamily. Real-time PCR (RT-PCR) analysis in different oyster tissues showed that og-TGF beta-like is specifically expressed in both male and female gonads, at... |