Genetic distances estimated from DNA fingerprints in crosses of White Plymouth Rock chickens

Crosses were produced between two lines of White Plymouth Rock chickens, one of which had been selected for low 8-week body weight for 31 generations (L) and the other of which was a bantam population (B). The parental lines, reciprocal F1s, reciprocal F2s and all possible back-crosses to each parental line (total of 16 populations) were available for study. Blood was obtained from 10 females within each population. DNA was extracted from blood mixes (equal amounts of blood from each individual) for each population, and from blood samples of each individual in the two parental lines. Fourteen line-specific DNA fingerprint (DFP) bands (those bands present in one parental population, but not in the other parental population) were analysed (eight from line L and six from line B). Regression analyses were conducted to compare the known proportion of genomic contribution from each parental population with values based on relative band intensity obtained with a scanning densitometer. The resulting regression coefficient of 1.004 demonstrated that DFP analysis of relative band intensity is an effective method of estimating the relative proportion of genome contributed by parental populations.