title: Complete mitochondrial genome sequencing reveals novel haplotypes in a Polynesian population.
abstract: The high risk of metabolic disease traits in Polynesians may be partly explained by elevated prevalence of genetic variants involved in energy metabolism. The genetics of Polynesian populations has been shaped by island hoping migration events which have possibly favoured thrifty genes. The aim of this study was to sequence the mitochondrial genome in a group of Maoris in an effort to characterise genome variation in this Polynesian population for use in future disease association studies. We sequenced the complete mitochondrial genomes of 20 non-admixed Maori subjects using Affymetrix technology. DNA diversity analyses showed the Maori group exhibited reduced mitochondrial genome diversity compared to other worldwide populations, which is consistent with historical bottleneck and founder effects. Global phylogenetic analysis positioned these Maori subjects specifically within mitochondrial haplogroup--B4a1a1. Interestingly, we identified several novel variants that collectively form new and unique Maori motifs--B4a1a1c, B4a1a1a3 and B4a1a1a5. Compared to ancestral populations we observed an increased frequency of non-synonymous coding variants of several mitochondrial genes in the Maori group, which may be a result of positive selection and/or genetic drift effects. In conclusion, this study reports the first complete mitochondrial genome sequence data for a Maori population. Overall, these new data reveal novel mitochondrial genome signatures in this Polynesian population and enhance the phylogenetic picture of maternal ancestry in Oceania. The increased frequency of several mitochondrial coding variants makes them good candidates for future studies aimed at assessment of metabolic disease risk in Polynesian populations.
authors.affiliation: School of Biological Science, Victoria University of Wellington, New Zealand.
authors.forename: Miles
authors.initials: M
authors.lastname: Benton
authors.forename: Donia
authors.initials: D
authors.lastname: Macartney-Coxson
authors.forename: David
authors.initials: D
authors.lastname: Eccles
authors.forename: Lyn
authors.initials: L
authors.lastname: Griffiths
authors.forename: Geoff
authors.initials: G
authors.lastname: Chambers
authors.forename: Rod
authors.initials: R
authors.lastname: Lea
mesh_terms: D004272:DNA, Mitochondrial / Q000235:genetics; D005828:Genetics, Population; D054629:Genome, Mitochondrial / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial