The evidence is weak for purging selection at individual loci in the lines undergoing relaxed selection, but the overall genome dynamics indicates that there is a general trend, particularly in the relaxed line derived from the low-weight line.
By also including later generations of selected birds, as well as two derivative relaxed selection lines founded by the high-weight and low-weight lines at generation 45, the analysis not only facilitates detection of novel sweeps on mutations that occurred after the divergence of the lines but also allows for estimation of when the mutation occurred.
To create the AIL used in this study, a large intercross pedigree was set up by crossing individuals from two divergent chicken lines, i.e. a High Weight Selected line (HWS) and a Low Weight Selected line (LWS), which were obtained as follows.
From a common base population, constituted by a mixture of seven partially inbred lines, two chicken lines have been selected for eight-week body weight; one towards high weights (high line, H) and the other towards low weights (low line, L).
Artificial selection of White Plymouth Rock chickens for juvenile (day 56) body weight resulted in two divergent genetic lines: hypophagic low weight (LWS) chickens and hyperphagic obese high weight (HWS) chickens, with the latter more than 10-fold heavier than the former at selection age.
In each generation, a given number of individuals NS were allowed to reproduce depending on their phenotype (highest weight individuals in the high line, lowest weight individuals in the low line).
Depending on this method, a PZT sensor array based impact monitor with advantages of miniaturized size, low weight and low energy consumption is developed which can meet the strict on-line application requests.
Main advantages of these detectors are high industrial resolution (3 5 line pairs per mm), detecting activity up to 20 μm, controlled sensitivity, low weight and small size, imaging low (0.1 0.3 mrad) object dose in real time.
Modern life means a low weight, fewer calories.
