STRUCTURAL-ANALYSIS OF THE MOUSE ACTIVIN BETA-C GENE

Using a mouse activin beta C cDNA probe, we have cloned over 38 kb of genomic DNA encompassing the mouse activin beta C gene. Mouse activin beta C is encoded by 2 exons separated by a large 12.1 kb intron. Exon 1 encodes the 17 amino acid signal peptide and 88 amino acids of the propeptide. Exon 2 encodes the remaining 130 amino acids of the propep tide and the entire 117 amino acid mature peptide. Unlike the activin beta A and beta B expression patterns, Northern blot analysis of adult mouse tissues shows that the activin beta C mRNA is expressed only in the liver as a major species of similar to 2.1 kb. The liver-specific expression of activin beta C suggests an important role of dimeric ac tivin beta C in normal liver function. These studies allow us to addre ss the function of activin beta C in mammalian development.