Genetic Technology Applied to Poultry Production 1 Genetic markers and their application in poultry breeding

S POULTRY SCIENCE ASSOCIATION August 8–11, 2002 Newark, Delaware * Author Presenting Paper Ancillary Scientists Symposium Genetic Technology Applied to Poultry Production 1 Genetic markers and their application in poultry breeding. M. G. Emara*1, H. Kim1, C. J. Schmidt1, K. S. Decker1, and H. S. Lillehoj2, 1University of Delaware, 2USDA-ARS, PBESL. The current chicken genetic map contains at least 1,965 loci within 50 linkage groups and it covers about 4,000 cM. About 235 of these loci have homology with known human or mammalian genes. The remaining loci are anonymous molecular DNA markers, including microsatellites, AFLP, RAPD, CR1 and others. A third generation genetic map for human research uses single nucleotide polymorphisms (SNPs), which has allowed mapping of complex traits by linkage disequilibrium analysis. With the tremendous advancement in characterizing chicken expressed sequences (ESTs), identification of genetic polymorphisms such as SNPs in chicken genes has become a reality. Our laboratories have undertaken an in silico process using a Phred/Phrap/Polyphred/Consed pipeline to identify candidate chicken SNPs in ESTs. Initial scanning of 23,427 chicken ESTs identified 1,219 candidate SNPs, and validation of the SNPs is ongoing. Placement of SNPs on the chicken genetic map will enhance marker density, thus allowing for fine mapping of complex traits. Application of genetic markers, including SNPs to identify disease resistance genes in commerical broilers will be discussed with regards to coccidiosis.