Abstract

The serological properties of the major histocompatibility (class I) antigens of mammals have raised many questions about the structure and function of these molecules. Over the past four years the cloning of their gene sequences has begun to provide some of the answers to these questions. The structural analyses have demonstrated close similarities between class I genes of man and mouse, established the existence of numerous class I pseudogenes in human and murine genomes, and indicated the importance of gene conversion events in regulating the sequence diversity of this gene family. In addition, the ability to construct new class I genes in vitro and to transfect cultured murine cells with the synthetic sequences is permitting new tests of the functional organization of these genes in relation to their structure.