Evolution of the mammalian class-mu glutathione transferase gene cluster

In humans, five class-mu glutathione transferase genes, GSTM1-5, are found clustered at chromosome 1p13.3. We have characterized the GSTM cluster in m acaques and partially characterized the cluster in mice. In macaques, the f ive GST Mu genes are closely related to their human orthologs but differ in the regions flanking the M1 deletion. Gene conversion of the intergenic re gions appears to have occurred after hominoids and old-world monkeys diverg ed 25 million years ago. Mice also have a similar tail-to-tail organization of in the mu-cluster, but the genes flanking the human GSTM3 (mouse mGSTM5 ) encode a novel cDNA, mGSTM7, and a possible pseudogene. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.