| Abstract: | Genetic contributions of nine historically important ancestors and allelic diversity inthe Japanese Thoroughbred population were examined by applying the gene droppingsimulation to the foals produced from 1978 to 2005. Full pedigree records traced toancestors (base animals) born around 1890 were used for the simulation. Alleles originatedfrom some of the historically important ancestors were found to be at risk of futureextinction, although their genetic contributions to the foal population have increasedduring the last three decades. The proportion of surviving alleles to the total allelesassigned to the base animals was 8.0% in the foal population in 2005, suggesting that alarge part of genetic variability contained in the base animals is extinct in the currentpopulation. |
