Figure 7

The well characterized splicing factor Fox2 is alternatively expressed and spliced during development. (a) Pre-mRNAs for this gene are transcribed using two primary promoters. (b) During development, the gene expression of Fox2, as detected by the meta probe set (MPS) 6836888 increases in embryos, while remaining generally lower and stable in placentas. (c) The use of the proximal promoter increases strongly during embryo development. (d) Fox2 expression levels modulate the alternative splicing of cassette exons containing putative Fox2 binding sites in their surrounding introns. The whiskers indicate the minimum and maximum value, the box represents the 25^th percentile to the 75^th, the line inside the box shows the 50^th percentile and the + is the value of the mean. The strict UGCAUG binding site or a combination of 5 binding sites (All) were looked for within 100 nt of the splicing sites in the upstream (Up) or downstream (Down) introns. The E11.5/E8.5 or E11.5/P11.5 exon inclusion ratios of the candidates were calculated using corresponding probe set levels, normalized by meta probe set levels. A ratio over 1 indicates that inclusion of the alternative exon follows expression of Fox2, while a ratio less than 1 means that these are negatively correlated. Using a one-tailed, unpaired t-test, we find that the means of the log of the ratios are significantly different (P < 0.05) between Up and Down data sets.