Genetic diversity of the toll-like receptor 2 (TLR2) in hare (Lepus capensis) populations from Tunisia

被引:3
作者
Awadi, Asma [1 ]
Ben Slimen, Hichem [1 ,2 ]
Smith, Steve [3 ]
Kahlen, Jonas [3 ]
Makni, Mohamed [1 ]
Suchentrunk, Franz [3 ]
机构
[1] Univ Tunis El Manar, UR Genom Insectes Ravageurs Cultures Interet Agro, Tunis 2092, Tunisia
[2] Univ Jendouba, Inst Super Biotechnol Beja, Beja 9000, Tunisia
[3] Univ Vet Med Vienna, Res Inst Wildlife Ecol, Savoyenstr 1, A-1160 Vienna, Austria
关键词
Toll-like receptor 2 (TLR2); TIR domain; Lepus capensis; Genetic diversity; Natural selection; Functional variation; INNATE IMMUNITY; PHYLOGENETIC ANALYSIS; SELECTION; POLYMORPHISM; MHC; LAGOMORPHA; CONSTRAINT; EVOLUTION; SEQUENCES; PRESSURE;
D O I
10.1016/j.crvi.2018.06.005
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Toll-like receptors (TLRs) are a major group of proteins that recognize molecular components of infectious agents, known as pathogen associated molecular patterns (PAMPs). The structure of these genes is similar and characterized by the presence of an ectodomain, a signal transmembrane segment and a highly conserved cytoplasmic domain. The latter domain is homologous to the human interleukin-1 receptor (IL1R) and human IL-18 receptor (IL-18R) and designated TIR domain. The latter domain of the TLR genes was suggested to be very conservative and its evolution is driven by purifying selection. Variability and evolution of the TIR sequences of TLR2 gene were studied in three hare populations from Tunisia with different ecological characteristics (NT-North Tunisia with Mediterranean, CT-Central Tunisia with semi-arid, and ST-South Tunisia with arid climate). Sequencing of a 372 bp fragment of TIR2 revealed 25 alleles among 110 hares. Twenty variable nucleotide positions were detected, of which 7 were non-synonymous. The highest variability was observed in CT, with 16 polymorphic positions. In ST, only 4 polymorphic nucleotide positions were detected with all diversity values lower than those recorded for the other two populations. By using several approaches, no positive selection was detected. However, evidence of purifying selection was found at two positions. The logistic models of the most common TIR2 protein variant that we run to examine whether itsn occurrence was affected by climatic variationin dependent of the geographic sample location suggested only a longitudinal effect. Finally, the mapping of the non-synonymous mutations to the inferred tertiary protein structure showed that they were all localized in the different loop regions. Among all non-synonymous substitutions, three were suggested to be deleterious as evidenced by PROVEAN analysis. The observed patterns of variability characterized by low genetic diversity in ST might suggest that the TIR region was more affected, than other markers, by genetic drift or/and that these patterns were shaped by different selective pressures under different ecological conditions. Notably, this low diversity was not detected by other (putatively neutral) microsatellite markers analysed in the course of other studies. But low diversity was also found for two MHC class II adaptive immune genes. As expected from functionally important regions, the evolution of the TIR2 domain is mainly driven by purifying selection. However, the occurrence of deleterious non-synonymous substitutions might highlight the flexible evolution of the TIR genes and/or their interactions with other proteins. (C) 2018 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
引用
收藏
页码:315 / 324
页数:10
相关论文
共 61 条
[11]   Variation of partial transferrin sequences and phylogenetic relationships among hares (Lepus capensis, Lagomorpha) from Tunisia [J].
Awadi, Asma ;
Suchentrunk, Franz ;
Makni, Mohamed ;
Ben Slimen, Hichem .
GENETICA, 2016, 144 (05) :497-512
[12]   Median-joining networks for inferring intraspecific phylogenies [J].
Bandelt, HJ ;
Forster, P ;
Röhl, A .
MOLECULAR BIOLOGY AND EVOLUTION, 1999, 16 (01) :37-48
[13]   Toll-like receptor 2 on inflammatory monocytes induces type I interferon in response to viral but not bacterial ligands [J].
Barbalat, Roman ;
Lau, Laura ;
Locksley, Richard M. ;
Barton, Gregory M. .
NATURE IMMUNOLOGY, 2009, 10 (11) :1200-U87
[14]   Evolutionary Dynamics of Human Toll-Like Receptors and Their Different Contributions to Host Defense [J].
Barreiro, Luis B. ;
Ben-Ali, Meriem ;
Quach, Helene ;
Laval, Guillaume ;
Patin, Etienne ;
Pickrell, Joseph K. ;
Bouchier, Christiane ;
Tichit, Magali ;
Neyrolles, Olivier ;
Gicquel, Brigitte ;
Kidd, Judith R. ;
Kidd, Kenneth K. ;
Alcais, Alexandre ;
Ragimbeau, Josiane ;
Pellegrini, Sandra ;
Abel, Laurent ;
Casanova, Jean-Laurent ;
Quintana-Murci, Lluis .
PLOS GENETICS, 2009, 5 (07)
[15]   Evaluating loci for use in the genetic analysis of population structure [J].
Beaumont, MA ;
Nichols, RA .
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 1996, 263 (1377) :1619-1626
[16]   Leucine-rich repeats and pathogen recognition in Toll-like receptors [J].
Bell, JK ;
Mullen, GED ;
Leifer, CA ;
Mazzoni, A ;
Davies, DR ;
Segal, DM .
TRENDS IN IMMUNOLOGY, 2003, 24 (10) :528-533
[17]  
Ben Slimen H, 2007, MAMM BIOL, V72, P224, DOI 10.1016/j.mambio.2006.03.002
[18]  
Ben Slimen H., 2008, THESIS
[19]   Selection on the mitochondrial ATP synthase 6 and the NADH dehydrogenase 2 genes in hares (Lepus capensis L.,1758) from a steep ecological gradient in North Africa [J].
Ben Slimen, Hichem ;
Schaschl, Helmut ;
Knauer, Felix ;
Suchentrunk, Franz .
BMC EVOLUTIONARY BIOLOGY, 2017, 17 :1-16
[20]   Toll-like receptor 2 Arg677Trp polymorphism is associated with susceptibility to tuberculosis in Tunisian patients [J].
Ben-Ali, M ;
Barbouche, MR ;
Bousnina, S ;
Chabbou, A ;
Dellagi, K .
CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY, 2004, 11 (03) :625-626