A total of 1704 macaques were screened for electrophoretic variants of NADP-dependent isocitrate dehydrogenase and six phenotypes of the enzyme were found in the blood samples from various populations of nine macaque species. M. mulatta from China was disclosed to be most polymorphic, with three postulated alleles resulting in six phenotypes . M. cyclopis and M. irus (except the philippine group) had two alleles with three phenotypes and the remaining species were homozygous for one of the two

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... ommon alleles (Idhmac1 and Idhmac2). One of the interesting finding was that the macaque species can be divided into two groups on the basis of the allelic distribution: those species with a high frequency of the Idhmac2 (M. fuscata, M. speciosa , M. mulatta, and M. cyclopis) and those with a high frequency of the Idhmac1 (M . irus, M. nemestrina, M. radiata, and M. niger). This might suggest phylogenetically divergent position between two groups of the macaque species. the homozygous phenotypes and as IDHmac 2-1 , 3-2 and 3-1 for the heterozygous phe-