Nematodes adversely affect animal health and cause serious economic losses; one option for control is the use of genetically resistant stock. There is an association between the MHC class II loci and resistance to nematode infections of sheep such as DRB1 gene. Our long-term aim is to fine-map the causative mutations but in order to design efficient and powerful experiments, we need to determine the extent of diversity at the different loci; therefore sequencing the second exons of all alleles at the DRB1 locus in 200 naturally infected lambs from the Texel breeds.
There was a significant association between some of the DRB1 alleles and the FECs which is considered one of the genetic markers for resistance to nematode infection and hence, this research reported here is considered an important achievement by providing better understanding of the genetic structure of the Ovar-MHC which improve the methods used in selective breeding to identify resistant and susceptible sheep.