Differential developmentally regulated expression of gelsolin family members in the mouse

The gelsolin family of actin-modulating proteins contains seven mammalian m embers of which three have similar domain structure and function: gelsolin, capG, and adseverin. Previous studies have provided some information on th e expression of these proteins, but no comprehensive analysis of expression during development has been performed. By in situ hybridization to murine embryo sections, we show that gelsolin expression is widespread but focal f rom e12.5 onward, with the exception of brain and mucosal epithelium. In co ntrast, CapG expression is high in mucosal epithelium, inner renal medulla, and adrenal cortex, and seen at much lower levels more broadly. Adseverin expression is even more restricted, being seen at sites of endochondral bon e formation during development only, and in developing and adult outer rena l medulla and intestine. In parallel analyses the three genes demonstrated patterns of expression that were complementary and nonoverlapping in nearly all organs. The observations suggest new functions for these proteins in o rgan systems and tissues where their expression was not previously recogniz ed, They further suggest that the proteins have distinct tissue-specific fu nctions in modulating the actin cytoskeleton during cellular motile activit ies, and that such functions have diverged since the genes arose ancestrall y by gene duplication. (C) 1999 Wiley-Liss, Inc.