Extending Pedigree Analysis for Uncertain Parentage and Diverse Breeding Systems

Breeding programs aimed at conserving genetic diversity in populations of wildlife or rare domestic breeds rely on detailed pedigree analysis for selection of breeders that will minimize the loss of alleles, reduce the accumulation of inbreeding, and maintain gene diversity. Commonly, techniques use a matrix of kinship coefficients to derive measures of genetic variation, inbreeding, and the value of individuals as breeders. Although these techniques were first developed for use on known pedigrees of diploid individuals, the concepts and methods can be extended to apply to any entity that contains genes derived from definable sources (e.g., individual parents, social groups, colonies, gene banks) via a definable mechanism of heredity (e.g., sexual reproduction between separate sexes, hermaphroditic selfing, autozygous production of homozygous or haploid offspring, cloning). Individuals with partly unknown ancestry or multiple possible parents can also be incorporated into kinship calculations, based on probabilistic assignment of parental contributions. This paper presents the algorithms used in new PMx software to extend traditional pedigree analysis techniques used for complete pedigrees of sexually reproducing, diploid species to deal with missing information due to unknown or uncertain parentage, and other breeding systems such as clones, selfing hermaphrodites, and haploid offspring or autogamy.