Culture of newt cells from different tissues and their expression of a regeneration‐associated antigen

Abstract
We have established culture conditions for cells from normal limb, early limb regenerate (blastema), heart, and liver of the newt Notophthalmus viridescens. Whereas heart and liver cells had a relatively short life in culture, limb cells have shown no sign of senescence over more than 1 year in culture. Cultured cells from all these tissues express to differing extents the regeneration-associated antigen 22/18. The antigen is intracellular and filamentous, and its expression appears to be regulated by culture density. Furthermore, 22/18 antigen is turned off in limb and blastemal cultures following differentiation into muscle, as also occurs in vivo.