Identification of single nucleotide variations in the Toll-like receptor 9 (TLR9) gene and its association to mastitis susceptibility in dairy cattle

• Published in: Biological rhythm research Vol. 50; no. 6; pp. 887 - 896
• Main Authors: Badami, Sharanabasav, Thanislass, Jacob, Barathiraja, Singaram, Anitha, Tamilmani, Upadhyaya, Indu, Kumar Mukhopadhyay, Hirak
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02-11-2019; Taylor & Francis Ltd
• Subjects: Adaptive immunity; Amino acids; Cattle; CpG islands; Immune response; Mastitis; Polymerase chain reaction; Polymorphism; Restriction fragment length polymorphism; single nucleotide variation; TLR9 protein; Toll-like receptor 9 (TLR9); Toll-like receptors; Variation
• DOI: 10.1080/09291016.2018.1502233
• EISSN: 1744-4179
• ISSN: 0929-1016

Toll-like receptors (TLRs) play a significant role in the host immune response. The TLR9 recognizes CpG DNA of bacteria and stimulate both the innate and adaptive immune responses. In the present study, functional domain (LRR) of TLR9 gene of mastitis-affected cows in comparison to apparently healthy animals was analyzed for any nucleotide variation as it may influence host susceptibility to disease conditions. LRR domain of TLR9 was amplified and analyzed for single-strand conformational polymorphism (SSCP). Samples shown altered SSCP mobility pattern were sequenced. Three nucleotide variations each in the two regions of functional domain were identified and the one corresponding to G→C variation at position 2318 of reference sequence (Accession No. AJ509824), suggesting the possible association with mastitis. Though the nucleotide variation did not result in amino acid change, it created an additional restriction site for Hae III which can be utilized in developing a new polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) marker.