PT  - JOURNAL ARTICLE
AU  - Robert M. Erdmann
AU  - P.R. V. Satyaki
AU  - Maja Klosinska
AU  - Mary Gehring
TI  - A small RNA pathway mediates global allelic dosage in endosperm
AID  - 10.1101/138750
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 138750
4099  - http://biorxiv.org/content/early/2017/05/16/138750.short
4100  - http://biorxiv.org/content/early/2017/05/16/138750.full
AB  - Balance between maternal and paternal genomes within the triploid endosperm is necessary for normal seed development. The majority of genes in Arabidopsis endosperm are expressed in a 2:1 maternal:paternal ratio, reflecting endosperm genomic DNA content. Here we find that the 2:1 transcriptional ratio is not, unexpectedly, a passive default but is actively regulated. We describe an inverse relationship between the parent-of-origin of small RNAs and mRNAs in endosperm on a genome-wide scale. Disruption of the Pol IV small RNA pathway causes the entire transcriptome to become more maternally biased. Furthermore, paternal inheritance of a RNA Pol IV mutation is sufficient to rescue seed abortion caused by excess paternal genome dosage. These results indicate that maintenance of the maternal:paternal transcriptome ratio in endosperm is an active process and reveal a function for RNA Pol IV in mediating the global transcriptional balance between maternally and paternally inherited genomes in endosperm.