A statistical approach to the analysis of DNA sequences has been developed, which provides a confidence interval estimate for the proportion of naturally occurring amino acid polymorphisms that are selectively neutral. When applied to the gnd gene coding for 6-phosphogluconate dehydrogenase in a sample of seven natural isolates of Escherichia coli, the method indicates that the proportion of observed amino acid polymorphisms that are selectively neutral is unlikely to be greater than 49% (upper 95% confidence limit). On the other hand, the observations are also consistent with a model in which all of the observed amino acid substitutions are mildly deleterious with an average selection coefficient approximating 1.6 X 10(-7). Various models for the distribution of configurations at silent sites are also investigated.
No takes yet. Share an insight, caveat, or question.
Sawyer et al. (1987) studied this question.
Synapse has enriched 2 closely related papers on similar clinical questions. Consider them for comparative context: