Functional study of a genetic marker allele associated with resistance to Ascaris suum in pigs

TY - JOUR

T1 - Functional study of a genetic marker allele associated with resistance to Ascaris suum in pigs

AU - Skallerup, Per

AU - Thamsborg, Stig Milan

AU - Jørgensen, Claus Bøttcher

AU - Enemark, Heidi L.

AU - Yoshida, Ayako

AU - Göring, Harald H.

AU - Fredholm, Merete

AU - Nejsum, Peter

PY - 2014/5

Y1 - 2014/5

N2 - Two single nucleotide polymorphisms (SNP TXNIP and SNP ARNT), both on chromosome 4, have been reported to be associated with roundworm (Ascaris suum) burden in pigs. In the present study, we selected pigs with two SNP TXNIP genotypes (AA; n=24 and AB; n=24), trickle-infected them with A. suum from 8 weeks of age until necropsy 8 weeks later, and tested the hypothesis that pigs with the AA genotype would have higher levels of resistance than pigs of AB genotype. We used different indicators of resistance (worm burden, fecal egg counts (FEC), number of liver white spots and A. suum-specific serum IgG antibody levels). Pigs of the AA genotype had lower mean macroscopic worm burden (2·4 vs 19·3; P=0·06), lower mean total worm burden (26·5 vs 70·1; P=0·09) and excreted fewer A. suum eggs at week 8 PI (mean number of eggs/g feces: 238 vs 1259; P=0·14) than pigs of the AB genotype, as expected based on prior associations. The pigs were also genotyped at another locus (SNP ARNT) which showed a similar trend. This study provides suggestive evidence that resistant pigs may be selected using a genetic marker, TXNIP, and provides further support to the quantitative trait locus on chromosome 4.

AB - Two single nucleotide polymorphisms (SNP TXNIP and SNP ARNT), both on chromosome 4, have been reported to be associated with roundworm (Ascaris suum) burden in pigs. In the present study, we selected pigs with two SNP TXNIP genotypes (AA; n=24 and AB; n=24), trickle-infected them with A. suum from 8 weeks of age until necropsy 8 weeks later, and tested the hypothesis that pigs with the AA genotype would have higher levels of resistance than pigs of AB genotype. We used different indicators of resistance (worm burden, fecal egg counts (FEC), number of liver white spots and A. suum-specific serum IgG antibody levels). Pigs of the AA genotype had lower mean macroscopic worm burden (2·4 vs 19·3; P=0·06), lower mean total worm burden (26·5 vs 70·1; P=0·09) and excreted fewer A. suum eggs at week 8 PI (mean number of eggs/g feces: 238 vs 1259; P=0·14) than pigs of the AB genotype, as expected based on prior associations. The pigs were also genotyped at another locus (SNP ARNT) which showed a similar trend. This study provides suggestive evidence that resistant pigs may be selected using a genetic marker, TXNIP, and provides further support to the quantitative trait locus on chromosome 4.

U2 - 10.1017/S0031182013002175

DO - 10.1017/S0031182013002175

M3 - Journal article

SN - 0031-1820

VL - 141

SP - 777

EP - 787

JO - Parasitology

JF - Parasitology

IS - 6

ER -