Improvement of the Maximum Avoidance of Inbreeding by the Use of Cell Manipulation Technique in Gametogenesis

Abstract

Reduction of genetic drift for preservation of genetic variability is one of the primary concerns for maintenance of endangered species in captivity. For this purpose, a number of selection schemes to equalize parental contributions to the next generation have been widely accepted as a simple guideline, but genetic drift due to random segregation of heterozygote parents, so-called Mendelian sampling, has remained unavoidable. In the past, the use of cell manipulation techniques developed in a field of mammal reproductive technology has been suggested to restrict this genetic drift. However, its potential benefit has been examined only for a randomly mating population of equal sex ratio. In this study, we assumed the situation where the cell manipulation technique is applied to the population under the mating system of maximum avoidance of inbreeding (MAI), and examined its effect on the progress of inbreeding by developing a recurrence equation of panmictic indices of the population. Inbreeding coefficient was substantially suppressed at the locus site where the mean number of crossovers between the site and centromere (m) was small. Although inbreeding coefficient inflated as m increased, its effect diminished as m increased. These tendencies were observed irrespective of the size of the population.