Examination of polymorphisms in the sequence encoding the extracellular domain of Suffolk and Kazak sheep’s Toll-like receptor 7

DOI: 10.18805/ijar.11421    | Article Id: B-409 | Page : 968-973
Citation :- Examination of polymorphisms in the sequence encoding the extracellular domain of Suffolk and Kazak sheep’s Toll-like receptor 7 .Indian Journal Of Animal Research.2018.(52):968-973

Xia Yang, Tian Liang, Xun Zhang, Su-fang Yang, Peng Wu, Yuan-yuan Xiao , Xin-kai Chen, Jia-wei SongÿGen-qiang Yan and Jin-liang Sheng

Address :

College of Animal Science and Technology, Shihezi University, Shihezi 832000, China.

Submitted Date : 4-12-2015
Accepted Date : 23-04-2016


Innate immune recognition of single-stranded RNA via Toll-like receptor 7 (TLR7) plays an important regulatory role in the development of the immune response. In the study, we used PCR-single-strand conformational polymorphism (PCR-SSCP) analysis to investigate genetic variations in the sequence encoding the ectodomain (ECD) of ovine TLR7. PCR was carried out using 12 different primer pairs (ECD-1– ECD-12), and polymorphisms were detected in the products for 4/12 pairs (ECD-2, -5, -6, and -7). ECD-2 and ECD -5 amplified products with mutations in Suffolk and Kazakstan sheep, while ECD-6 and ECD-7 amplified products with mutations only exist in Suffolk. The second pair of primers mutation in Suffolk does not conform to Hardy Weinberg equilibrium. As the mutations identified in this study may influence the structure and function of TLR7 and may thus affect the immune response to pathogens. The data indicate to undertake further disease associations studies to examine the usefulness of these findings in livestock breeding.


Extracellular domain Mutation Polymorphism TLR7.


  1. Bell, J. K., Mullen, G. E., Leifer, C. A., Mazzoni, A., Davies, D. R. and Segal, D. M. (2003). Leucine-rich repeats and pathogen recognition in toll-like receptors.. Trends in Immunology 24: 528–533.
  2. Berdeli, A., Celik, H. A., Özyürek, R., Dogrusoz, B. and Aydin, H. H. (2005). TIR-2 gene Arg753Gln polymorphism is strongly associated with acute rheumatic fever in children. Journal of Molecular Medicine 83: 535-541.
  3. Chang, J. S., Russell, G. C., Jann, O., Glass, E. J., Werling, D. and Haig, D. M. (2009). Molecular cloning and characterization of Toll-like receptors 1-10 in sheep. Veterinary Immunology & Immunopathology 127: 94–105.
  4. Franchimont, D., Vermeire, S., Housni, H. E., Pierik, M., Steen, K. V. and Gustot, T., et al. (2004). Deficient host-bacteria interactions in inflammatory bowel disease? the toll-like receptor (tlr)-4 asp299gly polymorphism is associated with crohn’s disease and ulcerative colitis..Alimentary Pharmacology & Therapeutics, 20: 303-10.
  5. Hawn, T. R., Misch, E., Dunstan, S. J., Thwaites, G. E., Lan, N. T., Quy, H. T. and Hien, T. T. (2007). A common human TLR1 polymorphism regulates the innate immune response to lipopeptides. European journal of immunology, 37: 2280-2289.
  6. Lan, T., Kandimalla, E. R., Yu, D., Bhagat, L., Li, Y., Wang, D. and Trombino, A. F. (2007). Stabilized immune modulatory RNA compounds as agonists of Toll-like receptors 7 and 8. Proceedings of the National Academy of Sciences, 104: 13750-13755.
  7. Lemaitre, B., Nicolas, E., Michaut, L., Reichhart, J. M. and Hoffmann, J. A. (1996). The dorsoventral regulatory gene cassette spatzle/toll/cactus controls the potent antifungal response in drosophila adults. Cell 86: 973-983.
  8. Masahiro, Y., Kiyoshi, T. and Shizuo, A. (2004). TIR domain-containing adaptors define the specificity of tlr signaling.. Molecular Immunology 40: 861–868.
  9. Mikula, I., Bhide, M., Pastorekova, S. and Mikula, I. (2010). Characterization of ovine TLR7 and TLR8 protein coding regions, detection of mutations and maedi visna virus infection. Veterinary Immunology & Immunopathology 138: 51–59.
  10. Møller-Larsen, S., Nyegaard, M., Haagerup, A., Vestbo, J., Kruse, T. A. and Børglum, A. D. (2008). Association analysis identifies TLR7 and TLR8 as novel risk genes in asthma and related disorders.Thorax 63: 1064-1069.
  11. Said, E. A., Al-Yafei, F., Zadjali, F., Hasson, S. S., Al-Balushi, M. S. and Al-Mahruqi, S., et al. (2014). Association of single-nucleotide polymorphisms in TLR7 (Gln11Leu) and TLR9 (1635A/G) with a higher CD4T cell count during hiv infection. Immunology Letters 160: 58-64.
  12. Schröder, N. W. and Schumann, R. R. (2005). Single nucleotide polymorphisms of toll-like receptors and susceptibility to infectious disease.. Lancet Infectious Diseases 5: 156–164.
  13. Seabury, C. M., Seabury, P. M., Decker, J. E., Schnabel, R. D., Taylor, J. F. and Womack, J. E. (2010). Diversity and evolution of 11 innate immune genes in bos taurus taurus and bos taurus indicus cattle..Proceedings of the National Academy of Sciences of the United States of America 107: 151-156.
  14. Goyal Shubham, Praveen K. Dubey, Kabita Tripathy, Ritu Mahajan, S. Pan and S. P. Dixit, et al. (2012). Detection of polymorphism and sequence characterization of Toll-like receptor 7 gene of indian goat revealing close relationship between ruminant species. Animal Biotechnology 23: 194-203.
  15. Takeda, K. and Akira, S. (2003). Toll-like receptors. Annu. Rev. Immunol 14: 335-376.
  16. Xu, Y., Tao, X., Shen, B., Horng, T., Medzhitov, R. and Manley, J. L., et al. (2000). Structural basis for signal transduction by the toll/interleukin-1 receptor domains.. Nature 408: 111-115.
  17. Yue, M., Gao, C. F., Wang, J. J., Wang, C. J., Feng, L., Wang, J. and Fan, N. J. (2014). Toll-like receptor 7 variations are associated with the susceptibility to HCV infection among Chinese females. Infection, Genetics and Evolution, 27: 264-270.

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