A comparison of the variability spectra of two genomic loci in a European group of individuals reveals fundamental differences pointing to selection or a population bottleneck

Ann Hum Genet. 2007 May;71(Pt 3):370-8. doi: 10.1111/j.1469-1809.2006.00342.x. Epub 2007 Jan 11.

Abstract

Knowledge about the variability spectra of neutrally evolving sequences in a population is a prerequisite for the identification of genes, which may have been under positive selection during recent human evolution. Here, we report the results of a re-sequencing project of a presumably neutrally evolving chromosome 22 locus with a severely reduced recombination frequency in a group of 24 individuals of German origin. The comparison of these data with the results of a similar analysis of a chromosome 17 locus revealed striking differences, although the same group of individuals was used. For the chromosome 17 locus two well-separated groups of sequences, a positive value of Tajima's D and a TMRCA of 700,000 years were observed. In contrast, the sequences from the chromosome 22 locus were found to be relatively homogeneous, with no deep splits between subgroups; the obtained value for Tajima's D was negative and the TMRCA was only 260,000 years. These discrepancies may be explained by selection or demographic processes. Regarding demography, the most plausible explanation is the assumption of a severe bottleneck in the history of the European population: in the case of the chromosome 17 locus two ancient lineages passed this bottleneck; for the chromosome 22 locus it was only one ancient lineage.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosomes, Human, Pair 17 / genetics
  • Chromosomes, Human, Pair 22 / genetics
  • DNA / genetics
  • Evolution, Molecular*
  • Genetic Variation*
  • Genetics, Population
  • Germany
  • Haplotypes
  • Humans
  • Linkage Disequilibrium
  • Models, Genetic
  • Phylogeny
  • Polymorphism, Single Nucleotide
  • Selection, Genetic*
  • White People / genetics

Substances

  • DNA