Molecular evolution of the three short PGRPs of the malaria vectors Anopheles gambiae and Anopheles arabiensisin East Africa

BMC Evolutionary Biology

Research Article

João Pinto¹  Joana Lamego¹  Virgílio E do Rosário¹  Henrique Silveira¹  Cristina Mendes¹  Ana-Margarida Sousa¹  Rute Felix¹  Derek Charlwood² 

[1] Centro de Malária e outras Doenças Tropicais, UEI Malária, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 96, 1349-008, Lisbon, Portugal;Centro de Malária e outras Doenças Tropicais, UEI Malária, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 96, 1349-008, Lisbon, Portugal;DBL - Centre for Health Research and Development, Faculty of Life, 57 Thorvandersvej, Fredriksberg, Copenhagen, Denmark;

关键词: Malaria Vector;    Hemocyte;    Nonsynonymous Substitution;    Immune Related Gene;    Phylogenetic Network;   

DOI  :  10.1186/1471-2148-10-9

 received in 2009-04-13, accepted in 2010-01-12,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundImmune responses to parasites, which start with pathogen recognition, play a decisive role in the control of the infection in mosquitoes. Peptidoglycan recognition proteins (PGRPs) are an important family of pattern recognition receptors that are involved in the activation of these immune reactions. Pathogen pressure can exert adaptive changes in host genes that are crucial components of the vector's defence. The aim of this study was to determine the molecular evolution of the three short PGRPs (PGRP-S1, PGRP-S2 and PGRP-S3) in the two main African malaria vectors - Anopheles gambiae and Anopheles arabiensis.ResultsGenetic diversity of An. gambiae and An. arabiensis PGRP-S1, PGRP-S2 and PGRP-S3 was investigated in samples collected from Mozambique and Tanzania. PGRP-S1 diversity was lower than for PGRP-S2 and PGRP-S3. PGRP-S1 was the only gene differentiated between the two species. All the comparisons made for PGRP-S1 showed significant P-values for Fst estimates and AMOVA confirming a clear separation between species. For PGRP-S2 and PGRP-S3 genes it was not possible to group populations either by species or by geographic region. Phylogenetic networks reinforced the results obtained by the AMOVA and Fst values. The ratio of nonsynonymous substitutions (Ka)/synonymous substitutions (Ks) for the duplicate pair PGRP-S2 and PGRP-S3 was very similar and lower than 1. The 3D model of the different proteins coded by these genes showed that amino acid substitutions were concentrated at the periphery of the protein rather than at the peptidoglycan recognition site.ConclusionsPGRP-S1 is less diverse and showed higher divergence between An. gambiae and An. arabiensis regardless of geographic location. This probably relates to its location in the chromosome-X, while PGRP-S2 and PGRP-S3, located in chromosome-2L, showed signs of autosomal introgression. The two short PGRP genes located in the chromosome-2L were under purifying selection, which suggests functional constraints. Different types of selection acting on PGRP-S1 and PGRP-S2 and S3 might be related to their different function and catalytic activity.

【 授权许可】

Unknown   
© Mendes et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.