Allelic variation in TLR4 is linked to resistance to Salmonella Enteritidis infection in chickens.
Salmonella Enteritidis (SE) is a foodborne pathogen that negatively affects both animal and human health. Polymorphisms of the TLR4 gene may affect recognition by Toll-like receptor 4 (TLR4) of bacterial lipopolysaccharide (LPS), leading to differences in host resistance to pathogenic infections. The present study has investigated polymorphic loci of chicken TLR4 (ChTLR4) in ten chicken breeds, electrostatic potentials of mutant structures of TLR4, and a linkage analysis between allelic variation and survival ratio to infection with SE in specific-pathogen-free (SPF) White Leghorns. A total of 19 Single Nucleotide Polymorphisms (SNPs), of which 10 were novel, were found in chicken breeds. Seven newly identified amino acid variants (C68G, G674A, G782A, A896T, T959G, T986A, and A1104C) and previously reported important mutations (G247A, G1028A, C1147T, and A1832G) were demonstrated in the extracellular domain of the ChTLR4 gene. Significant changes in surface electrostatic potential of the ectodomain of TLR4, built by homology modeling, were observed at the Glu83Lys (G247A), Arg298Ser (A896T), Ser368Arg (A1104C), and Gln611Arg (A1832G) substitutions. Linkage analysis showed that one polymorphic locus G247A of TLR4 gene, common in all breeds examined, was significantly associated with increased resistance to SE in SPF White Leghorns chicks (log-rank P-value = 0.04). The genotypes from A1832G SNPs did not show statistically significant survival differences. This study has provided the first direct evidence that G247A substitution in ChTLR4 is associated with increased resistance to Salmonella Enteritidis.
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.|University of Liège, Gembloux Agro-Bio Tech, Precision Livestock and Nutrition Unit, Passage des Déportés 2, 5030 Gembloux, Belgium.
Peng
P
Li
Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100093, China.
Huihua
H
Wang
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Xingwang
X
Zhao
Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.
Zhongyong
Z
Gou
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Ranran
R
Liu
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Yongmei
Y
Song
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Qinghe
Q
Li
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Maiqing
M
Zheng
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Huanxian
H
Cui
University of Liège, Gembloux Agro-Bio Tech, Precision Livestock and Nutrition Unit, Passage des Déportés 2, 5030 Gembloux, Belgium.
Nadia
N
Everaert
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Guiping
G
Zhao
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Jie
J
Wen
D000483:Alleles; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002645:Chickens; D060467:Disease Resistance; D008040:Genetic Linkage; D020641:Polymorphism, Single Nucleotide; D011201:Poultry Diseases / Q000276:immunology* / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000382:microbiology; D012477:Salmonella enteritidis / Q000502:physiology; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D051197:Toll-Like Receptor 4 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D030161:Avian Proteins; D051197:Toll-Like Receptor 4
Salmonella Enteritidis; chicken TLR4; homology modeling; polymorphism and genotypes