Abstract
Purpose: :
To map and identify the genes and mutation responsible for these canine oculo-skeletal dysplasias.
Methods: :
A genome wide scan of experimental 3-generation pedigrees informative for drd1 and drd2 was undertaken by the Mammalian Genotyping Service (Marshfield, WI), using the Marshfield canine screening set of 241 markers, a selection of canine microsatellite markers distributed relatively evenly across the canine genome. DNA was extracted from 138 dogs (4 normal, 43 carrier, 29 affected dogs for drd1, and 9 normal, 34 carrier, and 19 affected dogs for drd2). Two points linkage analysis was undertaken using Multimap.
Results: :
Positive linkage was detected for drd2 on canine chromosome CFA15 (REN06C11, theta = 0.055, lod =12.852), and strongly suggestive linkage for drd1 on chromosome CFA24 (FH2079, theta = 0.151, lod= 2.957). Sequencing of positional candidates in the interval is currently in progress.
Conclusions: :
Mutations in COL9A1 have previously been identified as causative in human autosomal recessive Stickler syndrome. Genome wide scans have ruled out this gene in canine OSD.However, these canine oculo-skeletal dysplasias are valuable models of autosomal recessive Stickler syndrome, and our results indicate that mutations in other collagen genes, or other novel genes, may account for previously unexplained cases of this syndrome in humans.
Keywords: genetics • development • retinal detachment