Search of genomic regions influencing faecal egg count, as an indicator of resistance to gastrointestinal nematode infections, based on the analysis of the OvineSNP50 BeadChip

Abstract

The objective of this study was to perform a preliminary search of genomic regions including Quantitative Trait Loci (QTL) underlying the resistance to gastrointestinal nematode infections (GIN) in a commercial population of Churra sheep by performing linkage (LA) and genome-wide association (GWA) analyses based on SNP-chip data. The studied population included 533 Churra ewes belonging to 15 half-sib families. The ewes and their sires were genotyped with the Illumina 50K BeadChip, whereas measurements of faecal egg count (FEC) were obtained for the ewes using the McMaster method. The LA analysis identified one QTL reaching the 5% chromosome-wise significance level on OAR8, whereas the GWA study found one marker exceeding that significance level on OAR6. A search of candidate genes was performed in the confidence intervals estimated for the QTL detected on these two chromosomes