Analysis of Genetic Diversity in the Czech Spotted Dog

SIMPLE SUMMARY: Losses of genetic diversity have a particular impact on breed populations in countries with a small breeding base or national breeds with a small registry. Among them, it is possible to include the breed of the Czech Spotted Dog (CSD), whose variability has been low since the beginning of breeding due to the small number of founders and mating of close relatives. Through study of its pedigree records, we recorded a severe loss of genetic variability and high relatedness between animals. Moreover, the population is not free of genetic diseases; therefore, future existence of the breed is in danger. ABSTRACT: Loss off genetic diversity negatively affects most of the modern dog breeds. However, no breed created strictly for laboratory purposes has been analyzed so far. In this paper, we sought to explore by pedigree analysis exactly such a breed—the Czech Spotted Dog (CSD). The pedigree contained a total of 2010 individuals registered since the second half of the 20th century. Parameters such as the mean average relatedness, coefficient of inbreeding, effective population size, effective number of founders, ancestors and founder genomes and loss of genetic diversity—which was calculated based on the reference population and pedigree completeness—were used to assess genetic variability. Compared to the founding population, the reference population lost 38.2% of its genetic diversity, of which 26% is due to random genetic drift and 12.2% is due to the uneven contribution of the founders. The reference population is highly inbred and related. The average inbreeding coefficient is 36.45%, and the mean average relatedness is 74.83%. The effective population size calculated based on the increase of inbreeding coefficient is 10.28. Thus, the Czech Spotted Dog suffered significant losses of genetic diversity that threaten its future existence.