Identification of class I major histocompatibility complex encoded molecules in the amphibian Xenopus.

Class I-like molecules have been immunoprecipitated from Xenopus leukocytes and erythrocytes with alloantisera directed against major histocompatibility complex (MHC)-linked antigens. The heavy chains, depending on the allele examined, have molecular weights of 40 000-44 000 of which 3000 daltons are asparagine-linked carbohydrates, probably present as one N-linked glycan. The presumed analogue of beta 2-microglobulin has a molecular weight of 13 000 and bears no asparagine-linked glycans. Family studies show that the heavy chains are encoded by genes residing in or closely linked to the MHC.