Therefore, this study was undertaken to (1) evaluate the susceptibility to haemonchosis in goat populations of China and Bangladesh under natural grazing conditions; (2) identify single nucleotide polymorphisms (SNPs) of NOD1 and NLRP9 genes; (3) then examine the associations of SNPs with disease resistance trait.
Identification of polymorphisms: Genomic sequences containing the caprine NOD1 and NLRP9 genes were used to detect SNP in these genes, and primers were designed using the NCBI Primer-BLAST web Program (https://www.ncbi.nlm.nih.gov/tools/primer-blast/) from the CDS of the NOD1 and NLRP9 genes (NCBI, Gen Bank association number: NW_017189490 and NW_017189504 respectively).
Primer pairs used for genotyping of caprine NOD1 and NLRP9 genes.
Amino acid replacement on SNPs in the NOD1 and NLRP9 genes.
Detection of SNPs in caprine NOD1 and NLRP9 genes: To associate disease resistance trait (FEC) with caprine NOD1and NLRP9 genes through screening of amplified DNA sequence, a total of six polymorphisms (3 in NOD1 and 3 in NLRP9 genes) were detected within the CDS sequences of goats in China and Bangladesh.
Population association analysis with FEC: Association analyses was carried out between SNP genotypes within the NOD1 and NLRP9 genes and disease resistance, as measured by FEC (Table 3).
Descriptive statistics analysis of caprine NOD1 and NLRP9 genes: Results of least square analysis (mean +- SE) (Table 4) revealed that the means for FEC were higher for goats with the GG genotype at the NOD1_146_A>G locus (904.43 +- 140.65epg) and goats with the AA genotype at the NLRP9_43_A>G locus (1129.57 +- 196.5epg).
NOD1 and NLRP9 genes have an immune regulatory function and multiple studies of these genes have been carried out on humans and a few livestock and aquaculture species (Kim et al.
Differential expression of NLRP9 was reported in infected and normal pre-implantation human embryos, and its expression was lower at day 1 but higher at day 3 and 5 in abnormal embryos (Zhang et al.
Despite the classic role of NOD1 and NLRP9 genes in the immune systems of humans and livestock species, there was no previous information on these two genes with regard to immune function in goats.