Why do we need to conserve what we have? A post-genome sequencing perspective on existing chicken strains.

The recent publication of the chicken genome sequence along with the extensive single nucleotide polymorphism and physical map open exciting avenues for defining gene function and for understanding the genotypic basis of phenotypic variation in the chicken. The number of genes identified on the sequence map is growing rapidly. Genetically uniform lines and crosses derived from them will allow identification of gene function and gene interactions that contribute to traits such as immunity, disease resistance, growth, production, and behavior. Selected, inbred, and congenic lines will continue to be essential in defining the genetics of many traits. Although dwindling under budgetary pressures, a number of well characterized lines and genetic strains remain. If preserved, these can be used to address questions regarding newly mapped candidate genes defining their importance in a variety of problems in basic, biomedical, and applied avian biology. If lost, years of breeding and selection will be required to replace them.