Effect of Sequence Variation in Bovine Mitochondrial DNA D-Ioop Region on ~ilk Production for Hanwoo

This study was performed to analyze the sequence variations of mtDNA D-loop and their effects onmilk in Hanwoo(Korean cattle). The resulting sequences were compared with previously publishedsequences for other cattle breeds (GenBank J01394). The Polymerase Chain Reaction was performed toamplify a total of 964 bp between nucleotide 15758 and 383 within D-loop region of mtDNA usingspecific primers. Twenty polymorphic sites by nucleotide substitution were found in mtDNA D-loopregion of Hanwoo. The frequencies of positions at 8, 169, 16042, 16051, 16057, 16093, 16119, 16122,16209, 16255 and 16302 nt with high levels of sequence polymorphism were 0.150, 0.950, 0.085, 0.138,0.106, 0.085, 0.138, 0.212, 0.085, 0.148 and 0.180, respectively. The substitution effect at 16119(p 0.1)and 16185(p 0.05) nt was found significant on milk production. Polymorphism of mtDNA sequence inD-loop region could be useful for the analysis of cytoplasmic genetic variation and associations with theother economically important traits and maternal lineage analysis in Hanwoo.(