Mitochondrial DNA polymorphisms in Yunnan nationalities in China

Abstract

Nucleotide sequences of the D-loop region of human mitochondrial DNA from four Yunnan nationalities, Dai, Wa, Lahu, and Tibetan, were analyzed. Based on a comparison of 563-bp sequences in 99 people, 66 different sequence types were observed. Of these, 64 were unique to their respective populations, whereas only 2 types were shared between the Lahu and Wa nationalities. The D-loop sequence variation and phylogenetic analysis suggested that the 99 mtDNA lineages were classified into eight clusters in the phylogenetic tree. All lineages that had a 9-bp deletion in the COII/tRNA Lys intergenic region appeared in one cluster in the D-loop tree, suggesting a single event of the deletion in the Yunnan nationalities studied. Genetic distances, based on net nucleotide diversities between populations including Han Chinese and mainland Japanese, revealed that the Dai, Wa, Lahu, and Han Chinese are closely related to each other, while Tibetan and mainland Japanese formed a single cluster. The bootstrap probability of separation between the Dai-Wa-Lahu-Chinese clade and the Tibetan-Japanese clade was 99%, indicating that there are at least two different origins among minority groups in Yunnan province. Although the genetic distance between Tibetan and Japanese within the clade is rather long, the results may shed light on the origins of mainland Japanese.

Phylogeographic analysis of mtDNA variation in four ethnic populations from Yunnan Province: new data and a reappraisal

“…Twentytwo haplotypes had many uncertainties when we considered their HVS-I variations and were classified as M* types. In these M* types, several clades with specific motifs could be discerned: The haplogroup classification of the mtDNAs contradicts the results of the phylogenetic analysis performed by Qian et al (2001a) by using the NJ method: in the eight clusters seen in their Figure 2, F types were divided into clusters 3 and 4 and D types were separated into clusters 7 and 8. The seventh cluster is very artificial from a phylogenetic point of view, for it contains types (M7b, D, M*, N9a, and A) from both macro-haplogroups M and N. Cluster 8 is also paraphyletic, for it harbors M*, D, D5, G2a, and M9 types.…”

“…By constructing a network relationship of the haplotypes (Bandelt et al 1995(Bandelt et al , 2000 and (near)matching them with published data sets, the potential errors in the data could be well distinguished. In the data of Qian et al (2001a;their Figure 1), several mistakes caused by base shifts are evident: (1) one Z haplotype (31) has a base shift at site 16185, and the original 16186 mutation is thus a mistake; (2) two D5 haplotypes (56 and 57) have a base shift at site 16189 so that the 16188 mutations in these two types are mistakes; and (3) haplotype 57 also has base shifts at sites 16164 and 16172, and the 16165 and 16173 mutations are mistakes. Note that all these obvious errors were found in both papers of Qian et al (2001a, b).…”

“…Note that all these obvious errors were found in both papers of Qian et al (2001a, b). Moreover, Qian et al (2001a) incorrectly identified type 57 as from a Dai individual and type 58 as from a Lahu individual in their Figure 1. Haplogroup status of each mtDNA was predicted according to the strategy described in Yao et al (2002b).…”

“…Since the Va and Lahu population samples were not included in our previous work (Yao et al 2002a), we collected data from 38 Vas from Ximeng and Gengma, Yunnan Province, and from 35 Lahus from Lancang, Yunnan Province, to compare with the data reported by Qian et al (2001a). Additionally, samples from three Dai from Xisuanbanna, Yunnan Province, were also sequenced here.…”

“…We used the same strategy as before (Yao et al 2002b) to predict the potential haplogroup status of the previously reported mtDNAs (Qian et al 2001a;Yao et al 2002a) as well as that of the new data considered here: we classified the mtDNAs into haplogroups according to the HVS-I motifs and (near)matching with the 327 Han mtDNAs (Yao et al 2002b;Kivisild et al 2002). When naming haplogroups, we followed the spirit and process described in Yao et al (2002b) and Kivisild et al (2002).…”