Polymorphisms Of TLR4 And Association With Genetic Susceptivity Of Digestive Disorders In Rabbits

Digestive disorders is the frequently severe disease resulted in great percentage death. Genetic factor is one of several factors affecting the occurrence of digestive disorders in rabbits.Toll-like receptor,is TMEM1 which plays an important role on anti-infection, can priming innate immune on the early stage of pathogen invade. In this study, we investigated the nucleotide sequence variations of exonl, exon2 and exon3 on the TLR4 gene for SNP and use HRM technology and gene sequencing to sudy the frequence of SNP among 10 breeds in 324 rabbits. The relationship between polymorphisms of TLR4 and association with genetic resistance of digestive disordefs in another group of Newzland rabbits studied by Case-Control.There are 125 samples in case group,and,we collect 147 samples which don't infect digestive disorders in control group. The results were as follows:This analysis revealed that there were total five cSNPs in exon 1 and exon 3. Of the five cSNPs, two cSNPs were synonymous which located in exon 1 (c.57 C>T, p.Ser19Ser) and in exon 3 (c.1098 G>A, p.Arg366Arg), respectively. The other three cSNPs were non-synonymous which located in exon 3 (c.566 G>A, c.760 G>A, and c.923 A>G) causing the p.Ser189Asn, p.Glu254Lys and p.Glu308Gly amino acid changed located in the extracellular domain of the protein TLR4.The frequence of five cSNPs on the TLR4 gene showed that the five TLR4 cSNPs are completely linkage Haplotype analysis show that the five SNPs can be constructed two haplotype (H1, CGGAG, wild-haplotype; H2, TAAGA, variant-haplotype),and H1 is dominant allele.The frequence of H1 gene in the ten breeds is from 0.6563 (Tianfu black rabbit) to 0.8571 (Bretonia rabbit),well,H2 is from 0.1429 (Bretonia rabbit) to 0.3437 (Tianfu black rabbit) The PIC of TLR4 gene in the ten breeds is from 0.2149(Bretonia rabbit)to 0.3495(Tianfu black rabbit),and the PIC of Fujian yellow rabbit,European rabbit,Champagne rabbit,Bretonia rabbit is under 0.25, are low polymorphism,the ohers 6 breeds reached to moderate polymorphismIn the Case-Control study,the H1 appeared 220 times(88%)in the Case group,233 times(79.3%)in the Control group.H2 appeared 30 times(12%)in the Case group,61 times (20.7%)in the Control group.The odds ratio (OR) for the association of allele significantly protective for digestive disorders disease was 0.521 (95% C.I.0.324-0.837, p=0.0064).It shows that H2 have a protect function.