Construction Of SNP Map In Regulatory And Coding Region Of TLR4 Gene In Chinese

The Tlr4 gene encodes the toll-like receptor 4 protein, which is a key receptor of LPS (endotoxin) in Gram- bacteria, and plays an important role in innate immunity. We use polymerase chain reaction (PCR) and direct-sequencing to investigate the regulatory region, 5'UTR, exon 1, 2, 3 and partial intron1, intron2 of Tlr4 gene in 100 unrelative individuals of Guangdong Han people for searching SNPs. 7 SNPs were found, while 6 of them were unidentified before. They are -271A/G and -259C/G located in regulatory region, 103T/G and 4024T/A located in intron1, 4126C/G in exon2, 9835G/T in exon3. Since the -271T/C and -259C/G are near the transcriptional start site, they may influence the transcription start of Tlr4. 4126C/G and 9835G/T are both non-synonymous cSNP. First can cause Ser (AGC) mutant to Arg (AGG), the second could cause Phe (UUC) mutant to Val (GUC). Based on the SNP map that been constructed, we also constructed the haplotype map of Tlr4 by PCR--SSCP. And the frequency of alleles and genotypes in Chinese are revealed as well. Analysis of these information indicatied that the coding region of Tlr4 gene is under negative selection. Our research made a good foundation for association studies of common diseases and assessment of individual predisposition to diseases in Chinese.