Mitochondrial DNA sequence polymorphisms of five ethnic populations from northern China

Abstract

To study the mitochondrial DNA (mtDNA) polymorphisms in a total of 232 individuals from five ethnic populations (Daur, n=45; Ewenki, n=47; Korean, n=48; Mongolian, n=48; Oroqen, n=44) in northern China, we analyzed the control region sequences and typed for a number of characteristic mutations in coding regions (especially the region 14576-16047), by direct sequencing or restriction-fragment-length-polymorphism (RFLP) analysis. With the exception of 14 individuals belonging to the European-specific haplogroups R2, H, J, and T, the mtDNAs considered could be assigned into the East Asian-specific haplogroups described recently. The polymorphisms in cytochrome b sequence were found to be very informative for defining or supporting the haplogroups status of East Asian mtDNAs in addition to the reported regions 10171-10659 and 14055-14590 in our previous study. The haplogroup distribution frequencies varied in the five ethnic populations, but in general they all harbored a large amount of north-prevalent haplogroups, such as D, G, C, and Z, and thus were in agreement with their ethnohistory of northern origin. The two populations (Ewenki and Oroqen) with small population census also show concordant features in their matrilineal genetic structures, with lower genetic diversities observed.

Phylogeographic analysis of mitochondrial DNA haplogroup F2 in China reveals T12338C in the initiation codon of the ND5 gene not to be pathogenic

“…The haplogroup status was further confirmed by detecting additional variations in other regions as described in our previous studies (Yao et al 2002aKong et al 2003a). A segment covering region 10171-10659 of the rCRS, which was suggested to be informative in defining East Asian specific haplogroups (Yao et al 2002a), was adopted to specify the phylogenetic status of the F* or R9* mtDNAs (the asterisk attached to haplogroups indicates that the sample was not able to be further classified into the sub-clade(s) of the haplogroup) in our previous studies (Yao et al 2000(Yao et al , 2002a(Yao et al ,c, 2003Yao and Zhang 2002;Kong et al 2003a) and unpublished data. For those published data sets (not from our laboratory) with only HVS-I and/or HVS-II information available, we recognized the potential F2 types by matching and/or near-matching with the identified F2 types that have been tested for coding region information.…”

“…All of the individuals were confirmed to be unrelated before sampling and were given informed consent. To better understand the phylogeny of haplogroup F2, the previously reported data sets (Yao et al 2000(Yao et al , 2002a(Yao et al ,c, 2003Tsai et al 2001;Kivisild et al 2002;Oota et al 2002;Yao and Zhang 2002;Kong et al 2003a;Tajima et al 2003) were also included. As a result, a total of 3,090 mtDNAs from 57 populations across China were examined, and their detailed information was illustrated in Table 1.…”

“…The nucleotide change was originally detected in two mtDNAs (GD7809 and QD8147) when we systematically surveyed mtDNAs belonging to all the major haplogroups specific to East Asian by complete mtDNA sequencing (Kong et al 2003b). To substantiate whether the T12338C change is specific to haplogroup F2 and to learn more about the origin of haplogroup F2, we performed an extensive search for F2 in more than 3,000 Chinese mtDNAs in reported studies (Yao et al 2000(Yao et al , 2002a(Yao et al ,c, 2003Tsai et al 2001;Kivisild et al 2002;Oota et al 2002;Yao and Zhang 2002;Kong et al 2003a;Tajima et al 2003) and our unpublished data by motif-searching and/or (near-)matching methods (Yao et al 2002a. Our phylogeographic study revealed that the T12338C change was specific to haplogroup F2 and occurred in normal individuals across China, thus suggesting a polymorphic change rather than a pathogenic mutation.…”

Ancient DNA from nomads in 2500-year-old archeological sites of Pengyang, China

“…In haplogroup C, the Han Chinese originating from the farming people 1,9,10 are concentrated in one group. Meanwhile, PW4 is clustered into another group with minorities in northern China, northern Asians and ancient nomads, 2,7,[12][13][14][15][16][17][18][19] suggesting that PW4 is closely related to the nomads. In haplogroups D4 and M10, the ancient people from Pengyang consistently occupy the same nodes as northern Asians, northern minorities of China and ancient nomads, showing a close genetic relationship among them.…”

“…Owing to conflicts between these two ethnic groups in the frontier, the nomads assimilated gradually into the Han Chinese population or became the minorities in northern China. 1,2 Therefore, the minorities in northern China and other northern Asians can trace their origins to the ancient nomads. 1 Archeological studies of the Zhongzhuang and Wangdahu sites, located in Pengyang in the southern Ningxia area in China (Figure 1), indicated that they were occupied from B770 BC to 256 BC during the Dongzhou period.…”