The microarray and Q-PCR datasets. The potential overlap of the microarray and Q-PCR datasets is depicted here. 'Region A' generically refers to the overlap between the datasets, 'Region B' to the part unique to the microarray and 'Region C' to that part unique to the Q-PCR series. It is clear from the context whether references to these regions in the main text refer to genes (top panel) or tissues probed (bottom panel). While up to 59 genes are simultaneously probed by both platforms, one would not necessarily expect their expression profiles to be identical in every case: differential contributions from (unknown) paralogs and/or closely related gene family members, as well as alternative splicing, can lead to distortions because the probes on the microarray and the primers used for the Q-PCR generally target different regions of a gene. Similarly, some tissues are probed simultaneously using both platforms, while others can be found in only one of the datasets. For a few tissues the overlap is hard to determine due to possible differences in developmental stage (shown in brackets; dgs = day old germinating seedling, dap = days after pollination, dba = days before anthesis, s = 10 cm seedling, ba = before anthesis). Further details about the tissues probed with the microarray may be found in Ref. , while details about those included in the Q-PCR series can be found in Ref. .