[Invariability of the H-Y Antigen Expression in the Heterogametic Sex of Some Amphbians and Evidence for Sexual Dimophrism of the Antigen Expression in Pelodytes Punctatus D (Amphibia, Anura)]

The H-Y antigen is studied in some Amphibians whose sexual genetic constitution is known. Thus, in Pelurodeles waltlii, Ambystoma mexicanum, Xenopus laevis and Rana ridibunda, the invariability of the H-Y antigen expression in the heterogametic, sex is confirmed. In Pelodytes punctatus the genetic sex is unknown but the existence of the H-Y antigen in phenotypic males leads to the conclusion of a male heterogamety of the XY type.