Current status of the river buffalo (Bubalus bubalis L.) gene map

Ninety-nine loci have been assigned to river buffalo chromosomes, 67 of whi ch are coding genes and 32 of which are anonymous DNA segments (microsatell ites), Sixty-seven assignments were based on cosegregation of cellular mark ers in somatic cell hybrids (synteny), whereas 39 were based on in situ hyb ridization of fixed metaphase chromosomes with labeled DNA probes. Seven lo ci were assigned by both methods. Of the 67 assignments in somatic cell hyb rids, 38 were based on polymerase chain reaction (PCR), 11 on isozyme elect rophoresis, 10 on restriction endonuclease digestion of DNA, 4 on immunoflu orescence, and 4 on chromosomal identification. A genetic marker or synteni c group has been assigned to each arm of the five submetacentric buffalo ch romosomes as well as to the 19 acrocentric autosomes, and the X and Y chrom osomes. These same markers map to the 29 cattle autosomes and the X and Y c hromosomes, and without exception, cattle markers map to the buffalo chromo some or chromosomal region predicted from chromosome banding similarity.