ASSESSMENT OF GENOMIC VARIABILITY THROUGH DNA-FINGERPRINTING WITHIN AND BETWEEN CHICKEN LINES DIVERGENTLY SELECTED FOR RESIDUAL FOOD-CONSUMPTION

DNA fingerprints obtained by multi-locus probes have been shown to be convenient tools to assess genetic variability and genetic distances i n animal populations. This method has been applied in the present stud y to two Rhode Island Red lines of chickens divergently selected for r esidual food consumption (RFC) for 16 generations (R-: low RFC; R+: hi gh RFC). Within each line, individuals were sampled from each tail of the phenotypic distribution of RFC for males and for females. The thre e probes used were two minisatellite probes, R18.1 and 33.6, and the e ndogenous avian retroviral element probe. Altogether, 101 bands were s cored. Band-sharing levels obtained from analysis of pooled DNA were e xtremely high within-line (> 0.9) and still high between the lines (0. 82 to 0.86). When band frequencies were compared, correlation coeffici ents were lower between lines than between extreme groups within lines regardless of the performance level. Although the selected lines diff ered widely in the selected trait RFC and a few correlated traits, it was concluded that they are probably different by only a low proportio n of their genome.