Fig. 6. Mechanism of differential readout of GATAa activity in pan-animal versus neural territories. Top: Schematic of the pfog-314 construct, showing the nucleotide position of the longest available EST, RACE-PCR fragments (results not shown) and position of an intron; green indicates sequences with basal promoter activity (-290). The putative GATA-binding sites of pfog are indicated in blue. Representative embryos electroporated with the indicated construct were stained for lacZ reporter activity at the 110-cell stage. A,B,D,E are animal views and C is a vegetal view; anterior to the top; n35. (A) Eliminating the intron maintains animal expression. (B) GATA sites from the otx neural a-element (red) maintain animal-wide expression. (C) -290 sequences in association with the ebra enhancer drive expression in notochord precursors and (D) in association with the otx neural a-element show neural and sporadic animal expression. (E) Ets site deletion can derepress animal-wide expression. (F) Quantification of constructs showing animal-wide expression. 90-100% indicates the percentage of embryos with all animal cells stained; 50-90% indicates the percentage of embryos with more than half of animal cells stained; <50% indicates the percentage of embryos with fewer than half of animal cells stained.