Identification of point mutation in Exon 2 of MBL1 gene and its relationship with Somatic Cell Score (SCS) in Sahiwal cattle

Mannose-binding lectin (MBL) is one of the most important constituent and a pattern recognition molecule of the innate immune system. MBL gene possibly contributes to bacterial infection resistance and was proposed as a molecular marker for milk production traits to control mastitis. Due to its location near to QTLs associated with Somatic cell score (SCS) and mastitis , the MBL1 gene may be considered as a candidate gene. Sahiwal cows in milk were selected randomly to identify g.2686T>C point mutation in exon 2 of MBL1 gene and its association with somatic cell score. A 401 bp PCR fragment of MBL1 gene encompassing the exon 2 was amplified and digested with Hae III to screen the reported SNP. Genotype analysis using PCR-RFLP revealed a polymorphic banding pattern. Sequencing was also carried out to validate the PCR-RFLP results of nucleotide sequence in a particular region. The preliminary information obtained from the study indicated that the targeted variantof MBL1 gene in indigenous cattle had no association with SCS and mastitis resistance which may be a breed specific characteristic. Since present study has formulated the results based on a relatively small sample size, further studies with large sample size are required to validate these results.