Journal article
Nucleotide polymorphism at the RpII215 gene in Drosophila subobscura. Weak selection on synonymous mutations
Genetics (Austin), Vol.155(3), pp.1245-1252
07/2000
PMCID: PMC1461163
PMID: 10880485
Abstract
Nucleotide variation in an 8.1-kb fragment encompassing the RpII215 gene, which encodes the largest subunit of the RNA polymerase II complex, is analyzed in a sample of 11 chromosomes from a natural population of Drosophila subobscura. No amino acid polymorphism was detected among the 157 segregating sites. The observed numbers of preferred and unpreferred derived synonymous mutations can be explained by neutral mutational processes. In contrast, preferred mutations segregate at significantly higher frequency than unpreferred mutations, suggesting the action of natural selection. The polymorphism to divergence ratio is different for preferred and unpreferred changes, in agreement with their beneficial and deleterious effects on fitness, respectively. Preferred and unpreferred codons are nonrandomly distributed in the RpII215 gene, leading to a heterogeneous distribution of polymorphic to fixed synonymous differences across this coding region. This intragenic variation of the polymorphism/divergence ratio cannot be explained by different patterns of gene expression, mutation, or recombination rates, and therefore it indicates that selection coefficients for synonymous mutations can vary extensively across a coding region. The application of nucleotide composition stationarity tests in coding and flanking noncoding regions, assumed to behave neutrally, allows the detection of the action of natural selection when stationarity holds in the noncoding region.
Details
- Title: Subtitle
- Nucleotide polymorphism at the RpII215 gene in Drosophila subobscura. Weak selection on synonymous mutations
- Creators
- A Llopart - Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, 08071 Barcelona, Spain. allopart@midway.uchicago.eduM Aguadé
- Resource Type
- Journal article
- Publication Details
- Genetics (Austin), Vol.155(3), pp.1245-1252
- Publisher
- United States
- PMID
- 10880485
- PMCID
- PMC1461163
- ISSN
- 0016-6731
- eISSN
- 1943-2631
- Language
- English
- Date published
- 07/2000
- Academic Unit
- Biology
- Record Identifier
- 9983991984902771
Metrics
18 Record Views