EXPRESSION OF MELTRIN-ALPHA MESSENGER-RNA IS NOT RESTRICTED TO FUSAGENIC CELLS

Meltrin-alpha is a myoblast gene product reported to be required for c ell fusion [Yagami-Hiromasa et al. (1995): Nature 377:652-656]. Becaus e Northern blots revealed expression only in muscle and bone, the sugg estion was made that meltrin-alpha is expressed exclusively by fusagen ic cells in these tissues (myoblast and osteoclast). We studied expres sion of meltrin-alpha mRNA in a panel of tissues and cell lines using the polymerase chain reaction and found it widely expressed. Meltrin-a lpha mRNA was readily detected in the osteoblast, the most abundant ce ll type in bone. In situ hybridization analysis on sections of neonata l mice revealed high levels of expression in the trabecular meshwork o f long bones, the basal regions of the dermis and its underlying mesen chyme. We conclude that expression of meltrin-alpha mRNA is not restri cted to fusagenic cells and that, in bone, the osteoblast is the major source. (C) 1997 Wiley-Liss, Inc.