GENETIC DIVERSITY OF ASIAN WATER-BUFFALO (BUBALUS-BUBALIS) - MITOCHONDRIAL-DNA D-LOOP AND CYTOCHROME-B SEQUENCE VARIATION

Swamp and river buffalo mitochondrial DNA (mtDNA) was sequenced for 30 3 bp of the cytochrome b gene for 54 animals from 14 populations, and for 158 bp of the D-loop region for 80 animals from 11 populations. On ly one cytochrome b haplotype was found in river buffalo. Of the four haplotypes identified in swamp buffalo, one found in all populations i s apparently ancestral both to the other swamp haplotypes and to the r iver haplotype. The phylogenetic relationships among the 33 D-loop hap lotypes, with a cluster of II found in swamp buffalo only, also suppor t the evolution of domesticated swamp and river buffalo from an ancest ral swamp-like animal, most likely represented today by the wild Asian buffalo (Bubalus arnee). The time of divergence of the swamp and rive r types, estimated from the D-loop data, is 28 000 to 87 000 years ago . We hypothesise that the species originated in mainland south-east As ia, and that it spread north to China and west to the Indian subcontin ent, where the rive type evolved and was domesticated. Following domes tication in China, the domesticated swamp buffalo spread through two s eparate routes, through Taiwan and the Philippines to the eastern isla nd's of Borneo and Sulawesi, and south through mainland southeast Asia and then to the western islands of Indonesia.