Genomic Imprinting in Arabidopsis thaliana and Zea mays.

Genomic imprinting is the differential expression of paternal and maternal alleles. In plants, gene imprinting occurs in the endosperm and has not been found in the embryo or adult plants. Imprinting can affect every allele of a locus (locus-dependent imprinting) or be specific to a particular allele (allele-dependent imprinting). Allele-dependent imprinting was the first type of gene imprinting discovered and has only been documented in maize. Locus-specific imprinting is found in both maize and Arabidopsis. Recent studies have revealed the integral role of female and male gametophytes in gene imprinting and mechanisms by which the parental alleles are distinguished from one another. Herein we will focus on the mechanisms of locus-specific gene imprinting in Arabidopsis and maize. [ABSTRACT FROM AUTHOR]