This is a review of the data of clonal analysis of developing tissues in parthenogenetic and androgenetic chimeric mice. The time and causes of death of the parthenogenetic and androgenetic cell clones in chimeras are considered. The data obtained suggest that the development of cell clones, derivatives of the mesoderm and endoderm, is determined by the expression of alleles of the imprinted loci of paternal chromosomes, while the formation of cell clones, derivatives of the ectoderm, depends on the expression of other imprinted loci of maternal chromosomes. The death of androgenetic and parthenogenetic (gynogenetic) mammalian embryos is due to the lack of the expression of certain imprinted loci of the maternal and paternal genome, respectively.