An ovine major histocompatibility complex DRB1 allele is associated with low faecal egg counts following natural, predominantly Ostertagia circumcincta infection.
Infection with Ostertagia circumcincta is a major constraint on sheep production in temperate areas of the world. A potential control strategy is the use of genetically resistant sheep. Therefore we examined the association between MHC-DRB1 alleles and faecal egg counts following natural, predominately O. circumcincta infection in a flock of Scottish Blackface sheep. Nineteen DRB1 alleles were identified by a combination of variation in the length of simple repetitive sequences within the intron between exons 2 and 3 and hybridisation of selected oligonucleotides to polymorphisms within exon 2. Faecal samples were taken from 200 lambs from one to six months of age at intervals of 4 weeks. Genetic effects were strongest at 6 months of age. Least-squares analysis indicated that substitution of the most common allele (I) by allele G2 would result in a 58-fold reduction in faecal egg counts in 6-month-old lambs and a 22-fold reduction in 5-month-old lambs. These results suggest that the major histocompatibility complex plays an important role in the development of resistance to O. circumcincta.
Schwaiger
F W
FW
Institute for Genetics, Ruhr-Universität, Bochum, Germany.
Gostomski
D
D
Stear
M J
MJ
Duncan
J L
JL
McKellar
Q A
QA
Epplen
J T
JT
Buitkamp
J
J
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D015342:DNA Probes / Q000235:genetics; D005243:Feces / Q000469:parasitology; D005260:Female; D008285:Major Histocompatibility Complex; D008297:Male; D008969:Molecular Sequence Data; D010029:Ostertagiasis / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D010270:Parasite Egg Count; D012756:Sheep / Q000235:genetics* / Q000276:immunology*; D012757:Sheep Diseases / Q000235:genetics / Q000276:immunology* / Q000469:parasitology
D015342:DNA Probes