INTROGRESSION OF THE AVIAN NAKED NECK GENE ASSISTED BY DNA FINGERPRINTS

Theoretical predictions suggest that DNA markers can be useful tools f or genomic selection in gene introgression programmes. An experiment w as carried out to evaluate the efficiency of using multi-locus DNA mar kers in an introgression programme designed to transfer the naked neck gene from a donor to a recipient chicken line. The donor line was a c ommercial egg layer chicken stock heterozygous at the naked neck locus (Na/na(+)), while the recipients were from a Cornish broiler line. Th ese two lines differ markedly in their average body weight, a quantita tive trait that can also represent the comprehensive differences betwe en the genomes of the two lines involved. Three groups of naked neck B C1 individuals were selected according to the following criteria: (i) low band-sharing with their donor grandsires evaluated by multi-locus DNA markers, (ii) high body weight at six weeks of age, and (iii) sele ction at random as a control group. Birds from each of these groups we re mated at random to individuals from the heavier Cornish line to pro duce three groups of BC2 individuals whose body weights were recorded weekly from three to seven weeks of age. Results indicated that BC2 bi rds obtained from BC1 parents selected for band-sharing levels and tho se selected for body weight, performed equally well at 4-7 weeks of ag e; both were 3.1-3.9% heavier than birds from the randomly selected gr oup. The additional genome recovery of the heavier broiler line, obtai ned by DNA markers, was found to be in agreement with theoretically pr edicted values.