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Evolutionary Dynamics of Large Numts in the Human Genome: Rarity of Independent Insertions and Abundance of Post-Insertion Duplications

Authors :
Rotem Sorek
Einat Hazkani-Covo
Dan Graur
Source :
Journal of Molecular Evolution. 56:169-174
Publication Year :
2003
Publisher :
Springer Science and Business Media LLC, 2003.

Abstract

We determined the phylogenetic positions of 82 large nuclear pseudogenes of mitochondrial origin (numts) within the human genome. For each numt, two possibilities pertaining to its origin were considered: (1) independent insertion from the mitochondria into the nucleus, or (2) genomic duplication subsequent to the insertion. A significant increase in the rate of numt accumulation is seen after the divergence of Platyrrhini (New World monkeys) from the Catarrhini (Old World monkeys, apes and humans). By using pairwise phylogenetic analyses, we were able to demonstrate that this peak in numt accumulation is mostly the result of duplication of preexisting nuclear numts rather than the result of an increase in mitochondrial-sequence insertion. In fact, only about a third of all the numt repertoire in the human nuclear genome is due to insertions of mitochondrial sequences, the rest originated as duplications of preexisting numts. Hence, we conclude that numt insertion occurs at a much lower rate than previously reported. As expected under the assumption that genomic duplications occur at rates that are uninfluenced by content, older numts were found to be duplicated more times than recently inserted ones.

Details

ISSN :
14321432 and 00222844
Volume :
56
Database :
OpenAIRE
Journal :
Journal of Molecular Evolution
Accession number :
edsair.doi.dedup.....351d19761a9d1f15b3e9a7ab5dd77621