Single nucleotide polymorphisms in toll-like receptor genes and case-control association studies with bovine tuberculosis

Abstract

Aim:Toll-like receptor 2 (TLR2) and TLR4 genes play critical roles in host recognition of Mycobacterium bovis infection and initiation of innate and adaptive immune response. The present study was aimed at exploring the association of seven single nucleotide polymorphisms (SNPs) in TLR2 and TLR4 genes with susceptibility/resistance against bovine tuberculosis (bTB) infection in cattle.Materials and Methods:A case-control resource population of 35 positive and 45 negative animals was developed after screening with single intradermal tuberculin test for bTB. Resource population was screened for SNPs in TLR2 and TLR4 genes using polymerase chain reaction-restriction fragment length polymorphism. The PROC LOGISTIC procedure of SAS 9.3 was used to find an association of allelic and genotypic frequencies with bTB.Results:In TLR2 gene, two of SNPs under study (rs55617172 and rs68268253) revealed polymorphism while in the case of TLR4 gene all four SNPs under investigation (rs8193041, rs207836014, rs8193060, and rs8193069) were found to be polymorphic in case-control population. SNP locus rs55617172 in TLR2 gene was found significantly (p<0.01) associated with susceptibility/resistance to TB in cattle.Conclusion:These findings indicate the presence of SNPs in TLR2 and TLR4 genes in our resource population. Upon validation in independent, large resource population and following biological characterization, SNP rs55617172 can be incorporated in marker panel for selection of animals with greater resistance to bTB.

Association of single nucleotide polymorphisms in the fatty acid synthase, LOC514211, and fat mass and obesity-associated genes with milk traits in Indonesian-Holstein dairy cattle

“…We used 100 samples (50 pairs of G 0 -G 1 ; G 1 was the daughter of G 0 ) that were still available on the farm and met the criteria of having individual first lactation milk yield and milk composition records. In fact, other studies on gene association and polymorphism used smaller sample sizes [16,19-21]. DNA from the samples was isolated from cow tail vein blood using a DNA Extraction Kit (gSYNC ™ , Geneaid, Taiwan) following the manufacturer’s protocol.…”

Resistencia natural contra la tuberculosis en ganado. Revisión

“…Richardson et al (34) , con 3,240 hatos lecheros irlandeses divididos en casos y controles, de acuerdo a resultados a la prueba de la tuberculina, y asumiendo el mismo nivel de exposición, obtuvieron un SNP (BovineHD0100019801) asociado a susceptibilidad a TBb, localizado en el cromosoma 1, y un SNP (Hapmap50596-BTA-121389) en el cromosoma 23 asociado con resistencia a TBb. Ello demuestra que existen SNP asociados con características de interés, y que pueden tener un efecto protector en las infecciones por M. bovis (36) , o contra la infección de tuberculosis pulmonar causada por M. tuberculosis en humanos (45) . Un ejemplo claro es el gen NOS2, esencial en la regulación de óxido nítrico, que puede matar o limitar el crecimiento de M. tuberculosis (35) .…”

Association of TLR2&nbsp;Haplotypes Encoding Q650 With Reduced Susceptibility to Ovine Johne’s Disease in Turkish Sheep

“…Among TLRs, TLR2 has a key role in recognizing the lipopeptide, peptidoglycan, mycolic acids, and lipoarabinomannan PAMPs of gram-positive bacteria and mycobacteria 12,13,14 . In the search for host alleles in uencing susceptibility to Johne's disease, candidate gene approaches targeting TLR gene family have revealed associations in cattle [15][16][17][18][19] and sheep 20 . Our interest in TLR2 was based on three observations: 1) its increased mRNA abundance soon after MAP infection in sheep 21 , 2) its actively involvement in the innate immune response against tuberculosis 22,23 and paratuberculosis diseases 15,16 , and 3) its missense variant association with susceptibility to mycobacterial infections in humans and farm animals 24 .…”