Assessment of collagen genes involved in fragmented medial coronoid process development in Labrador Retrievers as determined by affected sibling-pair analysis.
OBJECTIVE
To evaluate the involvement of various collagen genes in the development of fragmented medial coronoid process (FCP) in Labrador Retrievers.


METHODS
93 dogs originating from 13 litters were used in the study; FCP was diagnosed in 35 dogs, and each affected dog had at least 1 sibling that was also affected. Twelve dams and sires were included in the analysis. All dogs were purebred Labrador Retrievers except for 2 litters (offspring of a female Golden Retriever-Labrador Retriever mixed-breed dog).


METHODS
For each dog, DNA was isolated from blood samples. Polymorphic microsatellite markers adjacent to 14 candidate genes (ie, COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL6A3, COL9A1, COL9A2, COL9A3, COL10A1, COL11A1, COL11A2, and COL24A1) were analyzed by use of PCR assays; genotypes were determined via automated detection of DNA products. The level of allele sharing between pairs of affected siblings was assessed.


RESULTS
Among the 93 dogs, allele sharing of the 14 collagen genes was determined as follows: COL1A1, 45%; COL1A2, 47%; COL2A1, 37%; COL3A1, 32%; COL5A1, 43%; COL5A2, 32%; COL6A3, 36%; COL9A1, 45%; COL9A2, 49%; COL9A3, 38%; COL10A1, 46%; COL11A1, 52%; COL11A2, 47%; and COL24A1, 47%.


CONCLUSIONS
Because siblings share 50% of their genome at random, the fact that the percentages of allele sharing among the analyzed collagen genes were not significantly > 50% indicates that these genes are not determinant candidates for FCP in Labrador Retrievers. The gene for the vitamin D receptor could also be excluded because of its proximity to COL2A1.
Salg
Katja G
KG
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, PO Box 80154, 3508 TD Utrecht, The Netherlands.
Temwitchitr
Jedee
J
Imholz
Sandra
S
Hazewinkel
Herman A W
HA
Leegwater
Peter A J
PA
D000483:Alleles; D000818:Animals; D003094:Collagen / Q000235:genetics*; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs / Q000235:genetics*; D005260:Female; D005552:Forelimb / Q000254:growth & development*; D008040:Genetic Linkage; D007592:Joint Diseases / Q000235:genetics / Q000662:veterinary*; D008297:Male; D018895:Microsatellite Repeats; D010375:Pedigree; D035781:Siblings
D003094:Collagen