title: Dynamics of in vitro fitness recovery of HIV-1.
abstract: The study on the evolutionary consequences of an RNA viral population's fluctuations can be approached by in vitro experiments. This work describes the fitness recovery of HIV-1 after 20 large-population passages in 10 debilitated clones. The serial passages promoted an increase in viral fitness. In addition, we detected a significant number of mutations fixed in the complete genome consensus sequence of the final viral populations. Among the mutations, events of convergent evolution with important phenotypic characteristics occurred in several independent clones. One common change, V35I, in the nuclear localization signal of the p17 protein appeared in four viruses of three different lineages. Other common alterations mapped in position E196K of the reverse transcriptase or in position S316K of the V3 loop of the gp120 residue that is associated with the X4/R5 phenotype. Together with this mutational analysis, we studied the quasispecies heterogeneity of the initial and final viruses, revealing that fitness increase correlated with an augmentation in the genetic heterogeneity of viral quasispecies. However, while heterogeneity was mostly composed of synonymous (dS) mutations in the first 10 passages performed, at passage 21 it switched to nonsynonymous (dN) substitutions, with significant differences in dN - dS values between passages 11 and 21. In summary, the HIV-1 in vitro fitness recovery depicts a multiphase process occurring first by generation of mutations followed by fixation of the beneficial ones, depicting a classical Darwinian process.
authors.affiliation: Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Lorenzo-Redondo
authors.forename: Antonio V
authors.initials: AV
authors.lastname: Bordería
authors.forename: Cecilio
authors.initials: C
authors.lastname: Lopez-Galindez
mesh_terms: D019143:Evolution, Molecular; D016679:Genome, Viral; D015488:HIV Antigens / Q000235:genetics; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D015488:HIV Antigens; D015699:HIV Envelope Protein gp120; D012367:RNA, Viral; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase