GSE41391
An epigenetic role for disrupted paternal gene expression in postzygotic seed abortion in Arabidopsis interspecific hybrids
Interspecific hybrids in Arabidopsis result in seed abortion that causes reproductive barrier. To investigate the allelic expression pattern at transcriptome level during early seed abortion stage, we performed RNA-seq analysis in F1 interspecific hybrids with three different ecotypes in A. thaliana as maternal and A. arenosa as paternal and identified MEGs and PEGs. Interestingly, PEGs showed distinct expression pattern in several aspects, compared to MEGs: PEGs showed ecotype-specific expression pattern, suggesting a role for PEGs in ecotype-dependent seed lethality. 35% of previously known MEGs in non-lethal hybrids were found as PEGs in our lethal interspecific hybrids, implying the presence of abnormal paternal allelic upregulation. The correlation test between the upregulation of PEGs and previously reported paternal-excess interploidy cross (2X6) which exhibited seed abortion showed that dosage disruption by abnormal paternal upregulation is correlated with seed abortion. Moreover, epigenetic disruption appears to cause some of abnormal upregulation of paternal alleles in PEGs via mis-regulation of MEA-mediated PcG2 and MET1-mediated DNA methylation. The results provide clue on the critical role of PEGs in seed abortion via disruption of dosage balance and epigenetic regulation. Overall design: RNAsequensing of 3 F1 interspecific hybrids and 1 F8 allotetraploid from 4 DAP silique tissues in Arabidopsis