[Genomic imprinting as a universal mechanism of gene function in development]

The term genomic imprinting is used to designate the phenomenon of functional nonequivalence of alleles whose activities depend on their parental origin. A functional hemizygosity of the gene is characteristic for genomic imprinting. However, activities of alleles also depend on their parental origin in some cases of diallelic gene expression. These cases are described in the literature as possible examples of imprinting. In this paper, different manifestations of genomic imprinting are analyzed, and a hypothesis is suggested about the murine genome as a set of genes with different expressions of homologous alleles, whose activities depend on their parental origin.