Phylogenetic analysis of primate MIC (PERB11) sequences suggests that the representation of the gene family differs in different primates: comparisonof MIC (PERB11) and C4

Duplication of segments within the MHC has led to numerous multicopy famili es such as class I, class II, C4 and MIC (PERB11). Different copy numbers b etween haplotypes and species may be explained by the extent of duplication and subsequent deletion. There are at least five copies of MIC (PERB11) in humans, but MICA (PERB11.1) appears to have been deleted from the chimpanz ee. By comparing the sequences of primates (chimpanzee, gorilla, gibbon, orang- utan, pygmy chimpanzee, Patas monkey, Aethiops and baboon) we conclude that the gorilla has a copy of PERB11.1, whereas the baboon and Patas possess M ICD (PERB11.4) and/or MICE (PERB11.5 rather than MICA. (PERB11.1). These fi ndings indicate that the primate MHC is more plastic than has been apprecia ted.