Anopheles immune genes and amino acid sites evolving under the effect of positive selection

• Published in: PloS one Vol. 5; no. 1; p. e8885
• Main Authors: Parmakelis, Aristeidis, Moustaka, Marina, Poulakakis, Nikolaos, Louis, Christos, Slotman, Michel A, Marshall, Jonathon C, Awono-Ambene, Parfait H, Antonio-Nkondjio, Christophe, Simard, Frederic, Caccone, Adalgisa, Powell, Jeffrey R
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26-01-2010; Public Library of Science (PLoS)
• Subjects: Amino acids; Amino Acids - genetics; Animals; Anopheles; Anopheles - genetics; Anopheles - immunology; Base Sequence; Biodiversity; Bioinformatics; Biological evolution; Comparative analysis; Computational Biology/Comparative Sequence Analysis; Computational Biology/Molecular Genetics; Culicidae; DNA Primers; Drosophila; Evolution; Evolutionary Biology; Evolutionary Biology/Bioinformatics; Evolutionary Biology/Evolutionary and Comparative Genetics; Evolutionary genetics; Genes; Genetic algorithms; Genetic aspects; Genetic diversity; Genetic engineering; Genetic polymorphisms; Genetic research; Genetic Variation; Genetic vectors; Genetics; Genetics and Genomics; Genetics and Genomics/Genetics of Disease; Genetics and Genomics/Genetics of the Immune System; Genetics and Genomics/Population Genetics; Genomes; Genomics; Hypotheses; Hypothesis testing; Identification methods; Immunity; Immunity - genetics; Infections; Infectious Diseases; Innate immunity; Insects; Loci; Malaria; Medical research; Molecular biology; Mosquitoes; Natural populations; Natural selection; Parasites; Phylogenetics; Phylogeny; Plasmodium; Polymerase Chain Reaction; Polymorphism, Genetic; Population genetics; Positive selection; Recombination, Genetic; Researchers; Selection, Genetic; Species diversity; Studies; Taxonomy; Vector-borne diseases; Vectors; Greece; Crete; United States > US; Connecticut
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0008885

It has long been the goal of vector biology to generate genetic knowledge that can be used to "manipulate" natural populations of vectors to eliminate or lessen disease burden. While long in coming, progress towards reaching this goal has been made. Aiming to increase our understanding regarding the interactions between Plasmodium and the Anopheles immune genes, we investigated the patterns of genetic diversity of four anti-Plasmodium genes in the Anopheles gambiae complex of species.
Within a comparative phylogenetic and population genetics framework, the evolutionary history of four innate immunity genes within the An. gambiae complex (including the two most important human malaria vectors, An. gambiae and An. arabiensis) is reconstructed. The effect of natural selection in shaping the genes' diversity is examined. Introgression and retention of ancestral polymorphisms are relatively rare at all loci. Despite the potential confounding effects of these processes, we could identify sites that exhibited dN/dS ratios greater than 1.
In two of the studied genes, CLIPB14 and FBN8, several sites indicated evolution under positive selection, with CLIPB14 exhibiting the most consistent evidence. Considering only the sites that were consistently identified by all methods, two sites in CLIPB14 are adaptively driven. However, the analysis inferring the lineage -specific evolution of each gene was not in favor of any of the Anopheles lineages evolving under the constraints imposed by positive selection. Nevertheless, the loci and the specific amino acids that were identified as evolving under strong evolutionary pressure merit further investigation for their involvement in the Anopheles defense against microbes in general.