Low synonymous site variation at thelacY locus inEscherichia coli suggests the action of positive selection
| Autor: | Margaret A. Riley, Robert R. Wagner |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
DNA
Bacterial Nonsynonymous substitution Heterozygote Monosaccharide Transport Proteins Translational efficiency Molecular Sequence Data Locus (genetics) Biology medicine.disease_cause Intraspecific competition Evolution Molecular Loss of heterozygosity Escherichia coli Genetics medicine Selection Genetic Allele Molecular Biology Alleles Ecology Evolution Behavior and Systematics DNA Primers Polymorphism Genetic Base Sequence Models Genetic Symporters Escherichia coli Proteins Positive selection Genetic Variation Membrane Transport Proteins Genes Bacterial |
| Zdroj: | Journal of Molecular Evolution. 42:79-84 |
| ISSN: | 1432-1432 0022-2844 |
| DOI: | 10.1007/bf02198831 |
| Popis: | We have determined the nucleotide sequences of seven lacY alleles isolated from natural isolates of Escherichia coli. Nucleotide heterozygosity estimates for this locus were compared to those obtained from previous studies of intraspecific variation at chromosomal loci, revealing that lacY has unusually low synonymous site variation. The average pairwise heterozygosity of synonymous sites (Ks = 0.0112 +/- 0.0100) is the second lowest reported and the lowest for loci that have an equivalent level of nonsynonymous variation. We consider several hypotheses to explain how different forces in evolution could act to create the observed pattern of polymorphism, including selection for translational efficiency and positive selection. Our analysis most strongly supports the hypothesis that positive selection has acted on the lacY locus in E. coli. |
| Databáze: | OpenAIRE |
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