Association of single nucleotide polymorphism inNLRC3,NLRC5,HIP1, andLRP8genes with fecal egg counts in goats naturally infected withHaemonchus contortus

摘要

Haemonchus contortusis a common, intractably pathogenic and economically important gastrointestinal nematode for goat producers worldwide, especially in tropical and subtropical regions. The objective of this study is to identify single nucleotide polymorphisms (SNPs) of 12 candidate goat genes mainly related to the innate immune response associated with fecal egg counts (FECs) ofHaemonchus contortusin goat as an indicator of the level of parasite infection. Phenotypic data including FEC and blood traits were recorded in 189 native goats from China and 191 ones from Bangladesh, respectively. Bangladeshi goats had significantly (P< 0.01) lower FEC compared to that of Chinese goats, suggesting higher susceptible and infection rates in Chinese goat populations. FEC was significantly positive correlated with body weight (r= 0.64,P< 0.01) and hemoglobin (r= 0.49,P< 0.01) value, but negative with pack cell volume (r= - 0.63,P< 0.05) in goats. Genotyping of SNPs was performed using a matrix-assisted laser desorption ionization time of flight mass spectrometry assay and a generalized linear model was used to evaluate the association between each SNP and goat FEC trait. Eleven novel SNPs in theNLRC3,NLRC5,HIP1, andLRP8, out of 46 variants from these 12 genes, were significantly associated with FEC of goats with a nominal significance level ofP< 0.05. Of these 11 SNPs, linkage disequilibrium were revealed among SNPs inLRP8(r(2)= 0.87 to 1), between SNPs inNLRC3,NLRC5, andHIP1(r(2)= 0.96 to 0.99), respectively. Further, haplotypes withinNLRC3,NLRC5, andHIP1were significantly associated (P< 0.001) with FEC. In artificial challenge trail, quantitative real-time PCR exposed that the relative expression of mRNA was higher in the resistant group forNLRC3(P< 0.01),LRP8andHIP1(P< 0.001) but lower in the resistant group forNLRC5(P< 0.0001), compared to the susceptible group. The possible SNP markers and genes identified in this study could be potentially used in marker-assisted selection for breeding local goats breeds resistant to gastrointestinal nematode parasite particularly forHaemonchus contortus, and then for improving health and productivity of goat.