MtDNA variation and genetic signature of population reduction in three indigenous Korean cattle populations infered from mtDNA

In this study, we examined demographic history and genetic diversity of Korean Black, Jeju black and Korean Brindle cattle populations using complete mitochondrial DNA (mtDNA) control region sequences in order to facilitate the conservation of these cattle populations. 56 individuals were used for this study. The network analysis in general did not show a star-like pattern of population expansion events for these three cattle populations. The historic demographic expansion events investigated using mismatch distribution analyses were multimodal type both for combined and individual population data, suggesting either population equilibrium or a recent population reduction. Additionally, Tajima’s Fs and Fu’s D neutrality tests were not significant.
The tests suggested lack of demographic expansion episode in recent times, in support of the mismatch distribution analysis. The Haplotype diversity observed in the Jeju (0.88±0.04) and Brindle (0.98±0.03) cattle populations were high, but low haplotype diversity was detected in Korean black (0.37±0.13) cattle. The nucleotide diversities of Jeju, Brindle and Korean Black cattle were 0.005, 0.006 and 0.001, respectively. These cattle populations may have unique genetic merits, and further investigation is needed whether the recent reduction in population size observed in Korean indigenous cattle breeds could have had any negative impact on its genetic architecture.