Maternal epigenetic pathways control parental contributions to Arabidopsis early embryogenesis.

Authors:
Daphné Autran, Célia Baroux, Michael T Raissig, Thomas Lenormand, Michael Wittig, Stefan Grob, Andrea Steimer, Matthias Barann, Ulrich C Klostermeier, Olivier Leblanc, Jean-Philippe Vielle-Calzada, Phillip Rosenstiel, Daniel Grimanelli, Ueli Grossniklaus
Year of publication:
2011
Volume:
145
Issue:
5
Issn:
0092-8674
Journal title abbreviated:
CELL
Journal title long:
Cell
Impact factor:
28.710
Abstract:
Defining the contributions and interactions of paternal and maternal genomes during embryo development is critical to understand the fundamental processes involved in hybrid vigor, hybrid sterility, and reproductive isolation. To determine the parental contributions and their regulation during Arabidopsis embryogenesis, we combined deep-sequencing-based RNA profiling and genetic analyses. At the 2-4 cell stage there is a strong, genome-wide dominance of maternal transcripts, although transcripts are contributed by both parental genomes. At the globular stage the relative paternal contribution is higher, largely due to a gradual activation of the paternal genome. We identified two antagonistic maternal pathways that control these parental contributions. Paternal alleles are initially downregulated by the chromatin siRNA pathway, linked to DNA and histone methylation, whereas transcriptional activation requires maternal activity of the histone chaperone complex CAF1. Our results define maternal epigenetic pathways controlling the parental contributions in plant embryos, which are distinct from those regulating genomic imprinting.