A novel ficolin-related gene was isolated from the mouse liver lambda ZAPII cDNA library. The protein encoded by this gene consists of both collagen- and fibrinogen-like domains, which are common features of the ficolin family, and was named mouse ficolin-A. The amino acid sequence of mouse ficolin-A is 60.2, 59.8, 59.8, and 59.6% identical to those of porcine ficolin-alpha, -beta, human ficolin-1, and EBP-37/P35, respectively. Northern blot analysis showed that mRNA of mouse ficolin-A is highly expressed in liver and spleen. Immunoblot analysis using an anti-mouse ficolin-A antiserum showed that mouse ficolin-A is a plasma protein with binding activity to elastin and GlcNAc.