Human immunodeficiency virus type 1 molecular evolution and the measure of selection.


Journal Article

Human immunodeficiency virus (HIV) envelope genes are highly variable between and often within individuals. Part of this variability is thought to be the result of immune-mediated positive selection for sequence diversity. To measure positive selection it has become customary in HIV research to calculate the ratio of the proportions of synonymous (ds) and nonsynonymous (dn) substitutions per potential synonymous or nonsynonymous site, respectively. However, another measure that can be used is the difference between ds and dn, delta d. We show, by example, that using the ratio, ds/dn, or the difference, delta d, may lead us to different conclusions regarding the existence of positive selection pressure. We conclude by noting that until we understand the processes that mediate nucleotide variation in a host selective environment, inferences based on summary statistics characterizing types of nucleotide substitutions should be made with caution.

Full Text

Cited Authors

  • Rodrigo, AG; Mullins, JI

Published Date

  • December 1996

Published In

Volume / Issue

  • 12 / 18

Start / End Page

  • 1681 - 1685

PubMed ID

  • 8959243

Pubmed Central ID

  • 8959243

Electronic International Standard Serial Number (EISSN)

  • 1931-8405

International Standard Serial Number (ISSN)

  • 0889-2229

Digital Object Identifier (DOI)

  • 10.1089/aid.1996.12.1681


  • eng