Mutation analysis of the aggrecan gene in chickens with tibial dyschondroplasia.

Expression studies suggest that the incidence and severity of tibial dyschondroplasia (TD) in chickens, Gallus gallus, may be affected by the aggrecan gene, AGC 1. Here, results are described of a scan for single nucleotide polymorphisms (SNP) in AGC1 in genetic lines divergently selected for TD incidence in chickens. A total of 3,048 bp of DNA sequence obtained from amplicons produced by 4 primer-pairs designed from the GenBank AGC1 cDNA sequence were scanned for SNP. Among the 18 SNP detected and validated, only 2 were nonsynonymous. Allelic frequency differences between TD-affected and nonaffected birds were not statistically significant for all the SNP. The current results do not support an association of Gallus gallus AGC1 variation at the DNA level with the incidence of TD in chickens. The genomic resources described, however, including the SNP, could be useful in further evaluating AGC1 in other populations for association with TD or other skeletal abnormalities.