Zygotic genome activation and imprinting: parent-of-origin gene regulation in plant embryogenesis

• Published in: Current opinion in plant biology Vol. 27; pp. 29 - 35
• Main Authors: García-Aguilar, Marcelina, Gillmor, C Stewart
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2015
• Subjects: Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genome, Plant; Genomic Imprinting; Plants - embryology; Plants - genetics; Seeds - embryology; Seeds - genetics
• ISSN: 1369-5266; 1879-0356
• DOI: 10.1016/j.pbi.2015.05.020

•Zygotic genome activation and imprinting regulate allele-dependent gene expression in embryos.•Zygotic genome activation affects thousands of genes, while imprinting tens or hundreds.•Zygotic genome activation and imprinting are accomplished by different mechanisms. Parent-of-origin dependent gene expression refers to differential activity of alleles inherited from the egg and sperm. In plants, zygotic genome activation (ZGA) and gene imprinting are two examples of this phenomenon, both of which occur during seed development. As its name implies, ZGA is a genome-wide process that occurs in embryos during the first few days after fertilization. Evidence exists that maternal alleles initially predominate during ZGA, although most genes also show some paternal activity. By contrast, imprinting can be defined as a bias in gene expression that lasts beyond the first few days of seed development. Hundreds of imprinted genes have been discovered in the endosperm, and a few have been described in the embryo. This review discusses recent advances in our understanding of the phenomena and mechanisms of ZGA and imprinting in seeds, with an emphasis on embryo development. Important unanswered questions and areas for future research are highlighted.