Limb regeneration is a unique developmental phenomenon restricted to certain urodeles in which limb cells dedifferentiate and produce the blastema and then redifferentiate into the tissues that compose the missing part. Genetic modification of the blastema cells would greatly facilitate understanding the programmed gene expression that results in the reconstitution of the limb. To test whether pantropic retroviral vectors pseudotyped with the vesicular stomatitis virus G glycoprotein could mediate gene transfer into blastema cells, we infected a stable newt limb cell line and demonstrated integration and expression of the provirus. Thus, pantropic retroviral vectors offer a new tool for the study of limb regeneration and other developmental phenomena in amphibia.