Management of genetic diversity using gene dropping method based on pedigree information

Preservation of genetic diversity in populations is an important task to ensure a possible long-term response to selection in animal breeding. The purpose of this study was to consider how pedigree analysis and gene dropping method could be used for management plans in order to maintain genetic variation in a population under selection of Japanese quail. Therefore, the distributions of alleles frequencies originated from founders were estimated using gene dropping simulation software on an actual pedigree. Then, genetic contribution of founders to current population, components such as the F-statistics and effective population sizer were estimated. The results show that from 156 founders there are only 64 of them (22 males and 42 females) in the last generation. The average genetic contribution of a founder male and female contributing to the last generation were 1.87 and 1.40%, respectively. A total of 87 and 95% of the genome in the last generation were constituted by 34 and 42 founders, respectively. The effective population size decreased as inbreeding increases. The allele frequency averaged over replicates agreed with the genetic contribution. Some useful information regarding to the management of genetic diversity such as the probability of allele extinction, the probability of alleles surviving at a critically low frequency, and risk of future allele extinction were derived by suing these distribution. Results show that pedigree analysis and gene dropping are valuable tools in optimizing decisions to preserve genetic variability.