AGL36 is only expressed from the maternal genome.

(A) Real-time PCR analysis showing AGL36 expression in Ler x cdka;1 relative to Ler x Col seeds 3 DAP. Gray bars represent Ler x Col expression levels, black bars represent the Ler x cdka;1 expression levels. Left section: AGL36 normalized to ACT11 levels. Right section: AGL36 normalized to GAPA levels. Average values from three independent biological replicas are shown. Error bars indicate standard deviation (STDEV). (B) Schematic overview of AGL36 SNP analysis. The presence of a SNP between Col and Ler ecotypes (C-T conversion respectively) allows the amplified AGL36 cDNA PCR product from the Col ecotype to be digested with AlwNI restriction enzyme, while the Ler ecotype remains undigested. (C) AGL36 is maternally expressed. Seeds obtained from Col x Ler and Ler x Col crosses were harvested at 3 DAP followed by AGL36 RT-PCR, AlwNI digestion and subsequent Bioanalyzer analysis. Genomic Col and Ler were included as controls (Left section, first two lanes). Digestion products of two independent biological replicas of maternal Col x Ler pollen crosses produced only Col bands, indicating maternal expression (Middle section). Similarly, the digestion products of two independent biological replicas of maternal Ler x Col pollen produced only Ler bands, indicating maternal expression (Left section). The intensities of the bands are represented as concentrations (nmol/L), and create a basis for comparison. 100 ng DNA was used as template for each PCR reaction.