Effects of geographic origin on captive Macaca mulatta mitochondrial DNA variation.

Partial sequences from mitochondrial (mt) 12S and 16S rRNA genes were analyzed to characterize diversity among captive rhesus macaques (Macaca mulatta) originating from various geographic regions. Several nested clades, defined by closely related haplotypes, were identified, suggesting considerable genetic subdivision, probably relics from heterogeneous origins, founder effects, and genetic drift, followed by breeding isolation. The rhesus matrilineages from India differed discretely and markedly from Chinese matrilineages; approximately 90% of the genetic heterogeneity among the combined samples of Indian and Chinese rhesus macaques studied here was due to country of origin. In addition, mtDNA sequences from macaques of China were more diverse than those from rhesus macaques of India, an outcome consistent with China's greater subspecies diversity and with nuclear genotype distributions. Otherwise, the distribution of mtDNA variation within rhesus macaques of China, and especially within those of India, exhibited far less structure and did not conform to a simple isolation-by-distance model. As the demand for genetically heterogeneous and well-characterized rhesus macaques for biomedical-based research increases, mtDNA haplotypes can be useful for genetically defining, preserving maximal levels of genetic diversity within, and confirming the geographic origin of captive breeding groups of rhesus macaques.