Study of MTCYB gene sequence in populations of Taiwan

The cytochrome B gene (MTCYB) within the mitochondrial genome has been widely used in species identification and taxonomic research. In this study, the population variation of the MTCYB gene in humans was demonstrated. The sequence polymorphism of the MTCYB gene was determined in 417 subjects in 8 populations in Taiwan (Taiwan Chinese, mainland Chinese, Filipino, Thai, Vietnamese, and Caucasian). Single nucleotide polymorphisms of the populations and the genetic distance between these populations were analyzed. There were 108 variable positions with a total of 99 haplotypes. The distribution of varied sequences from the revised Cambridge Reference Sequence (rCRS) was from 1 to 9 positions, with an average of 4.26. Discrimination powers of the MTCYB gene in the 8 populations, ranging from 0.7888 (Tao) to 0.9224 (Filipino), were observed. A population-specific position of the MTCYB gene was noted in Tao and Caucasian populations in this study. There were statistically significant differences of genetic distance between Taiwan Chinese and Caucasian, between Taiwan Chinese and Tao, and between Taiwan Chinese and Filipino. A phylogenic tree using the neighbor-joining method based on the MTCYB gene sequence of these populations was constructed, which grouped the Taiwan Chinese, indigenous Taiwanese, mainland Chinese, Thais, and Vietnamese in the same cluster. In conclusion, there are sufficient sequence polymorphisms of the MTCYB gene in individuals of different populations, which can be used in the identification of human ethnic groups, and the analyses of forensic casework.