Molecular Evolution Activities
 

This is a comprehensive bibliography (under construction) of primary and secondary sources on the neutral theory of molecular evolution. It currently covers the period 1973-2001.

Author :

Munte, A.;Aguade, M.;Segarra, C.

Year :

2001

Title :

Changes in the recombinational environment affect divergence in the yellow gene of drosophila

Journal :

Molecular Biology and Evolution

Volume :

18

Issue :

6

Pages :

1045-1056

Date :

Jun

Short Title :

Changes in the recombinational environment affect divergence in the yellow gene of drosophila

Alternate Journal :

Mol. Biol. Evol.

Custom 2 :

ISI:000169180200017

Abstract :

The complete coding region of the yellow (y) gene was sequenced in different Drosophila species. In the species of the melanogaster subgroup (D. melanogaster, D. simulans, D. mauritiana, D. yakuba, and D. erecta), this gene is located at the tip of the X chromosome in a region with a strong reduction in recombination rate. In contrast, in D. ananassae (included in the ananassae subgroup of the melanogaster group) and in the obscura group species (D. subobscura, D. madeirensis, D. guanche, and D. pseudoobscura), the y gene is located in regions with normal recombination rates. As predicted by the hitchhiking and background selection models, this change in the recombinational environment affected synonymous divergence in the y-gene-coding region. Estimates of the number of synonymous substitutions per site were much loa er between the obscura group species and D. ananassae than between the species of the obscura group and the melanogaster subgroup. In fact, a highly significant increase in the rate of synonymous substitution was detected in all lineages leading to the species of the melanogaster subgroup relative to the D. ananassae lineage. This increase can be explained by a higher fixation rate of mutations from preferred to unpreferred codons (slightly deleterious mutations). The lower codon bias detected in all species of the melanogaster subgroup relative to D. ananassae (or to the obscura group species) would be consistent with this proposal. Therefore, at least in Drosophila, changes in the recombination rate in different lineages might cause deviations of the molecular-clock hypothesis and contribute to the overdispersion of the rate of synonymous substitution. In contrast, the change in the recombinational environment of the y gene has no detectable effect on the rate of amino acid replacement in the Yellow protein.

Notes :

Times Cited: 0 440MZ MOL BIOL EVOL
 -- contributed by John Beatty, March 29, 2002