Parent-of-origin effects in seeds of Arabidopsis thaliana: Affymetrix

Crossing plants of the same species but different ploidies can have dramatic effects on seed growth, but little is known about the alterations to transcriptional programmes responsible for this. Parental genomic imbalance particularly affects proliferation of the endosperm, with an increased ratio of paternally to maternally contributed genomes (‘paternal excess’) associated with overproliferation, while maternal excess inhibits endosperm growth. One interpretation is that interploidy crosses disrupt the balance in the seed of active copies of parentally imprinted genes. This is supported by the observation that mutations in imprinted FIS-class genes of Arabidopsis thaliana share many features of the paternal excess phenotype. Here we investigated gene expression underlying parent-of-origin effects in Arabidopsis through transcriptional profiling of siliques generated by interploidy crosses and FIS-class mutants. Two biological replicate samples each of 2xX2x, 2xX4x, 2xX6x, 6xX2x, 4xX2x and fis1X2x and a single sample of msi1. Each sample was hybridised to a separate array.