Association of Toll-Like Receptor 4 Polymorphisms with Somatic Cell Score and Lactation Persistency in Holstein Bulls

摘要: Mastitis, an inflammatory disease of the mammary gland generally caused by intramammary infections, is most frequently occurring in North American dairy industry. Reduced milk yield, quality, and lactation persistency as well early culling contribute to economic losses associated with this disease. During cells innate immune system become activated through pattern recognition receptors that recognize conserved molecular signatures invading pathogen. The timing, intensity host subsequent response determine fate Toll-like receptor 4 (TLR4) important recognizes endotoxins gram-negative bacterial infections. Its role pathogen initiation makes it a suitable candidate gene for enhancing resistance Canadian Holsteins. In study, polymorphisms TLR4 were identified Holstein bull population. Genotypes haplotypes constructed, their associations somatic cell score determined. Sequencing selective DNA pools was used reveal TLR4. Two constituted based on high low estimated breeding values scores. A total 3 single nucleotide (SNP), including 1 SNP putative promoter region (P-226) 2 exon3 (E3+1656 E3+2021) detected. 388 bulls genotyped SNP, reconstructed, frequencies obtained. Polymorphisms these regions found be persistency, scores unfavorable alleles at P-226 E3+1656 frequency 40 37%, respectively; hence, selection against promising Selection allele, T E3+2021, limited because its (7%). (GCC CTC) occurred 86% population chosen genotyping. frequent haplotype (GCC; 54%) higher lower transversion potential binding site.