Figure 3
Genome-wide mapping of EOPRA. (A) Results of the genome-wide association study (GWAS) obtained from analyzing the Illumina SNP chip data showing the negative log of the raw p values calculated with the genotypic association test (minimum p value = 0.0001400861). Top right, QQ-plot showing the expected quantiles (x axis) of the log p values versus the observed (y axis). The moderate skewing of a marker toward the upper side suggests a weak association with the “affected” condition compared with what would be expected by mere chance. The flat-line at expected − log(p value) = 3.85 (highest p value reported of 0.00014) is likely caused by the high stratification thus justifying the complementary mapping methods used. (B) Multipoint parametric linkage carried out with a subset of the data representing a nuclear family of dogs consisting of 2 parents, 4 affected and 2 unaffected full siblings. Positive LOD scores (2.501) were found on canine chromosome 20 with a critical interval of 20.63 Mb (position 29.33–49.96 Mb). (C) Recap of the different mapping hits obtained through the different methods used. Genome regions identified by positive LOD scores in linkage analysis, by homozygosity mapping, and by the highest peaks in GWAS are indicated in green, red, and blue, respectively. Note the triple hit on canine chromosome 20.
