Luísa Pereira,

IPATIMUP – Instituto de Patologia e Imunologia Molecular da Universidade do Porto –

Abstract:

Mitochondrial DNA (mtDNA) studies were always instrumental in phylogenetic inferences, namely in the field of human population genetics, allowing to placing the root of the human tree in East Africa, about 200,000 years ago. The success is such that sequencing efforts led already to the publication of more than 4,300 complete human mtDNAs (each ~16,600bp) and more than 7,600 complete eukaryote mtDNA genomes on GenBank. But if some of its characteristics make analyses easier and straightforward, such as the absence of recombination, other demands some conceptual modifications. One of these is the circularity of the molecule which renders common alignment algorithms and informatics tools, developed for linear molecules, not suitable for automatic alignment of many circular mtDNA genomes. Furthermore, the high heterogeneity in mutational rates between the two main regions in mtDNA (control and coding regions) and even between positions inside regions (namely between first/second and third codon positions) questions the validity of attributing the same weights to substitutions and the same gap penalties all over the molecule. The development and implementation of efficient cyclic algorithm is now crucial to retrieving most information from the huge amount of sequencing data being accumulated for mtDNA.

 

Date: 2008-May-29     Time: 16:30:00     Room: 336

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