December 18, 2005

Dazzling Indian mtDNA haplogroup M

Mmm, I don't think I've seen the word "dazzling" on a paper title yet. Of interest from the paper:
A particular case in question is the origin of haplogroup M1, which is mainly found in Northeast Africa and the Near East (Quintana-Murci et al. 1999). Due to the fact that M1 bears variant nucleotides, for example, at site 16311 in common with haplogroup M4, at 16129 with M5, and at 16249 with haplogroup M34, it has been proposed that M1 might have some affinity with Indian M haplogroups (Roychoudhury et al. 2001). This inference, however, could not receive support from our complete sequencing information. Indeed, the reconstructed ancestral motifs of all Indian M haplogroups turned out to be devoid of those variations that characterized M1, i.e., 6446, 6680, 12403, and 14110 (Maca-Meyer et al. 2001; Herrnstadt et al. 2002). Therefore, those common mutations in the control region rather reflect random parallel mutations. There is no evidence whatsoever that M1 originated in India.
It was pointed out that macrohaplogroups M, N, and R are universally distributed in Eurasia but differentiated into distinct haplogroups in East Asia, Oceania, Southeast Asia, and theAndaman Islands in particular (Macaulay et al. 2005; Thangaraj et al. 2005). This finding is further strengthened by our newly obtained Indian M data since the mutations that characterize the basal M lineages in India are virtually unique and not shared by those of East Asian, Oceanian, and Southeast 16 Asian M lineages (Ingman et al. 2000; Ingman and Gyllensten 2003; Kong et al. 2003; Tanaka et al. 2004; Friedlaender et al. 2005; Macaulay et al. 2005). This star-like and non-overlapping pattern of the mtDNA phylogeny is in good agreement with the proposed scenario that the initial dispersal of modern human into Eurasia some 60 thousand years ago was rather rapid along the Asian coastline (Macaulay et al. 2005; Thangaraj et al. 2005; Forster and Matsumura 2005).
Molecular Biology and Evolution (advance access)

The Dazzling Array of Basal Branches in the mtDNA Macrohaplogroup M from India as Inferred from Complete Genomes

Chang Sun et al.


Many efforts based on complete mitochondrial DNA (mtDNA) genomes have been made to depict the global mtDNA landscape, but the phylogeny of Indian macrohaplogroup M has not yet been resolved in detail. To fill this lacuna, we took the same strategy as in our recent analysis of Indian mtDNA macrohaplogroup N and selected 56 mtDNAs from over 1,200 samples across India for complete sequencing, with the intention to cover all Indian autochthonous M lineages. As a result, the phylogenetic status of previously identified haplogroups based on control-region and/or partial coding-region information, such as M2, M3, M4, M5, M6, M30, and M33, was solidified or redefined here. Moreover, seven novel basal M haplogroups (viz. M34-M40) were identified and yet another five singular branches of the M phylogeny were discovered in the present study. The comparison of matrilineal components among India, East Asia, Southeast Asia, and Oceania at the deepest level yielded a star-like and non-overlapping pattern, reflecting a rapid mode of modern human dispersal along the Asian coast after the initial "Out-of-Africa" event.


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