[Comparative analysis of the complete mitochondrial genome between Tibetan and Han population].
OBJECTIVE
To construct the haplogroup and perform an analysis of mitochondrial whole-genome sequence in Tibetan and Han Chinese. Variations of nucleotide of mitochondrial DNA (mtDNA) were identified and compared between the Tibetan and Han population.


METHODS
The mtDNA whole sequences of 40 Tibetan and 50 Han individuals were sequenced by an Applied Biosystems 3730 DNA automatic sequencer. The sequences were assembled using software phredPhrap16.0, and all assembled sequences were manually verified according to the criterion of rCRS (revised Cambridge Reference Sequence). The haplogroups of mtDNA were constructed using phylogenetic analysis according to the criteria of MITOMAP by Network method. The data were elucidated by integrated methods.


RESULTS
Authors' results showed that all the pooled 90 subjects belonged to the Macrohaplogroup M and N, and were classified into 13 haplogroups. No differences were observed among the haplogroups of the two populations except for M9 haplogroup. A total of 21 variants were detected by comparing the mtDNA whole sequences between Tibetan and Han population; of those, 5 variants have not been reported before. In addition, we constructed the haplotypes of 5 variants harboring the D-loop region, and founded prominent difference in both supertype 1 and supertype 2 between Tibetan and Han population.


CONCLUSIONS
The phylogenetic analysis indicates that the Tibetan and Han ethnic groups shared close maternal relationship in origin. The biological implication of the significant variants is worth elucidating; whether they are the results of adaptive selection or neutral selection or pathological variations need to be further studied.
Gu
Ming-liang
ML
Department of Medical Genetics, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, Yunnan, 650118 People's Republic of China.
Wang
Ye-jun
YJ
Shi
Lei
L
Jiang
Feng
F
Qiu
Meng-jie
MJ
Lin
Ke-qin
KQ
Tao
Yu-fen
YF
Shi
Li
L
Huang
Xiao-qin
XQ
Liu
Bin
B
Chu
Jia-you
JY
D044466:Asian People / Q000235:genetics; D002681:China / Q000208:ethnology; D004272:DNA, Mitochondrial / Q000032:analysis*; D005006:Ethnicity / Q000235:genetics*; D019143:Evolution, Molecular; D005828:Genetics, Population; D054629:Genome, Mitochondrial / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D018609:Tibet / Q000208:ethnology
D004272:DNA, Mitochondrial