Resquencing of Australian Aboriginal mtDNA and Y chromosomes. Y. Xue1, M. Cerezo Fernandez1, Y. Chen1, S. McCarthy1, MO. Pollard1, Q. Ayub1, N. Nagle2, P. McAllister3, RJ. Mitchell2, C. Tyler-Smith1 1) Wellcome Trust Sanger Institute, Cambridge, United Kingdom; 2) Department of Genetics, La Trobe University, Melbourne, Australia; 3) Griffith University, Gold Coast, Queensland, Australia.
Modern humans originated in Africa and spread across the rest of the globe 50-70 thousand years ago. The first identified divergence outside Africa was between the ancestors of the Australian Aborigines and some nearby populations on the one hand, and the ancestors of Asians, Europeans and other non-Africans on the other hand. The genetic characterization of this divergence and subsequent events in Australian Aboriginal history before the colonial era remain poorly described. Seven Australian Aboriginal males requested sequencing of their mitochondrial DNA (mtDNA) and Y chromosomes, and we generated high depth Illumina 100 bp paired-end sequence data. The average coverage is ~15-20x for Y chromosome and ~3000x for mtDNA. The mtDNAs of the samples belong to new branches of haplogroups P (5 individuals), M (1 individual) and O (1 individual). These haplogroups are known from Australia, but the many new variants illustrate their diversity and distinct origins. The Y chromosomes belong to haplogroups C (3 individuals), K* (3 individuals), both previously known from Australia, and M (1 individual). This last haplogroup has a restricted geographical distribution centred on Papua New Guinea, and illustrates a genetic link between Australia and that region. The ~3,000 new Y-SNPs present in these samples are permitting refined estimates of the ancient coalescence times between Australian lineages and those in the rest of the world, and re-examination of the hypothesis of more recent links between Australia and South Asia, originally based on Y-chromosomal similarities.