BioProject

Balance between maternal and paternal genomes within the triploid endosperm is necessary for normal seed development. More...

Balance between maternal and paternal genomes within the triploid endosperm is necessary for normal seed development. The majority of endosperm genes are expressed in a 2:1 maternal:paternal ratio, reflecting genomic DNA content. Here we find that the 2:1 transcriptional ratio is, unexpectedly, actively regulated. In A. thaliana and A. lyrata, endosperm 24 nt small RNAs are reduced in TEs and enriched in genes compared to the embryo. We find an inverse relationship between the parent-of-origin of sRNAs and mRNAs, with genes more likely to be associated with maternally than paternally biased sRNAs. Disruption of the Pol IV sRNA pathway causes a shift toward maternal allele mRNA expression for many genes. Furthermore, paternal inheritance of an RNA Pol IV mutation is sufficient to rescue seed abortion caused by excess paternal genome dosage. Thus, RNA Pol IV mediates transcriptional balance between maternally and paternally inherited genomes in endosperm. Overall design: Examination of parent-of-origin specific and total gene expression in wild type, nrpd1, and WT female x nrpd1 male endosperm 6-7 days after pollination - 11 samples. Less...