Genetic Polymorphisms in the Swine (Sus scrofa) Natural-resistance-associated Marophage Protein 1 Gene(Nramp1) and Their Relationships with Piglet Diarrhea
Abstract：Natural-resistance-associated marophage protein 1 gene (Nramp1) plays an important role in controling body's immune regulation. To explore genetic variation and its relevant molecular markers in piglet diarrhea of the swine (Sus scrofa) Nramp1 gene, this research detected the polymorphisms of Nramp1 gene in five pig populations by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) technique and analyzed their associations with piglet diarrhea by adopting the generalized least squares method. Two alleles (A and T) and three genotypes (AA, AT and TT) were detected in the Nramp1 gene exon 2, two alleles (C and T) and three genotypes (CC, CT and TT) were detected in its intron 6. The distributions of genotypes were significantly different among Hezuo pig and other four pig breeds (Landrace, Large White, Duroc and Gansu Black pigs) (P＜0.01); the genotypic distributions of Hezuo pigs were significantly deviated from Hardy-Weinberg equilibrium in both exon 1 and intron 6 (P＜0.05), whereas in other pig populations were all consistent with Hardy-Weinberg equilibrium (P＞0.05). The least square linear contrasts suggested that diarrhea score of genotype AA was significantly higher than that of TT (P＜0.05), and extremely significantly higher than that of AT (P＜0.01) in exon 2; CC genotype had significantly higher diarrhea score than that of CT (P＜0.05). The results indicate that there are important effect on piglet diarrhea of different Nramp1 gene genotypes, which can provide basic data for the genetic makers of diarrhea anti-disease breeding.
