Germ Plasm and Germ Cell Determination in Xenopus laevis As Studied by Cell Transplantation Analysis

Abstract

This paper will review separate but related groups of data on the ontogeny and possible roles of germ plasm in the establishment of the germ line in anuran amphibian embryos. We shall discuss the paradoxical situation that germ plasm is apparently necessary for the normal formation and/or the migration of primordial germ cells (PGCs), but that at the same time PGCs remain pluripotent, at least until they reach the gonad, and are not determined in the classical sense of being restricted in potential to form only germ line cells.