An electrophoretic analysis of proteins of cellular sap in normal and hybrid frog embryos

ABSTRACT The degree of abnormality found in amphibian interspecies hybrids varies from one species pair to another, and may also differ between reciprocal matings (Moore, 1955). Although some general ideas exist about the mechanism of arrest and the course of abnormal development, our knowledge is far from complete. One major aspect of development which has received attention only at the gross level is the nature and diversity of those proteins which compose the greater part of the cytoplasmic sap, the ‘soluble’ proteins in the sense of this paper (see below). This paper reports the results of studies on the development of normal (Ranapipiens) and gastrula-arrested hybrid (R. pipiens ♀×R. sylvatica ♁) amphibian embryos.