Abstract: Cellular libraries useful for in vitro phenotyping and gene mapping. In a representative approach, a method for preparing a homozygous cellular library includes the steps of providing a heterozygous cellular library comprising a plurality of isolated parent cells; inducing site-specific mitotic recombination in the plurality of isolated parent cells; culturing the plurality of isolated parent cells, whereby a population of daughter cells is produced; and selecting daughter cells comprising a homozygous genetic modification, whereby a homozygous cellular library is prepared.

Abstract: Cellular libraries useful for in vitro phenotyping and gene mapping. In a representative approach, a method for preparing a homozygous cellular library includes the steps of providing a heterozygous cellular library comprising a plurality of isolated parent cells; inducing site-specific mitotic recombination in the plurality of isolated parent cells; culturing the plurality of isolated parent cells, whereby a population of daughter cells is produced; and selecting daughter cells comprising a homozygous genetic modification, whereby a homozygous cellular library is prepared.

Abstract: A novel population for genetic mapping, methods for generating the disclosed population, and methods for using the disclosed population for efficient identification of genetic loci that modulate a phenotype. Also provided are methods for identifying interactions between genetic loci and non-genetic factors that modulate a phenotype. Further provided are methods for defining epistatic relationships among genes gene networks and non-genetic factors.