Mitochondrial Portraits of Human Populations Using Median Networks

AUTOR(ES)

Bandelt, H. J.

RESUMO

Analysis of variation in the hypervariable region of mitochondrial DNA (mtDNA) has emerged as an important tool for studying human evolution and migration. However, attempts to reconstruct optimal intraspecific mtDNA phylogenies frequently fail because parallel mutation events partly obscure the true evolutionary pathways. This makes it inadvisable to present a single phylogenetic tree at the expense of neglecting equally acceptable ones. As an alternative, we propose a novel network approach for portraying mtDNA relationships. For small sample sizes (< ~50), an unmodified median network contains all most parsimonious trees, displays graphically the full information content of the sequence data, and can easily be generated by hand. For larger sample sizes, we reduce the complexity of the network by identifying parallelisms. This reduction procedure is guided by a compatibility argument and an additional source of phylogenetic information: the frequencies of the mitochondrial haplotypes. As a spin-off, our approach can also assist in identifying sequencing errors, which manifest themselves in implausible network substructures. We illustrate the advantages of our approach with several examples from existing data sets.

Documentos Relacionados

• Survey of human mitochondrial diseases using new genomic/proteomic tools
• Pairwise Comparisons of Mitochondrial DNA Sequences in Subdivided Populations and Implications for Early Human Evolution
• Disruption of Mitochondrial Networks by the Human Cytomegalovirus UL37 Gene Product Viral Mitochondrion-Localized Inhibitor of Apoptosis
• Mitochondrial DNA phylogeography of Brazilian populations of Drosophila buzzatii
• Reduced Y-Chromosome, but Not Mitochondrial DNA, Diversity in Human Populations from West New Guinea