Fig. s2

Supp. Fig. 2. GAL4VP16 expressed by trapped endogenous enhancers strongly activates UAS:DsRedExDR reporter expression, but disrupts normal development. A–S: F1 embryos derived from crossing of the GAL4VP16 enhancer-trap founders with the UAS:DsRedExDR reporter line demonstrated strong DsRedExDR reporter expression at 30 to 36 hpf. In these F1 embryos, two classes of DsRedExDR-expression were recognized: strong, region-specific expression, and weak, widespread expression. The first class of DsRedExDR expression probably resulted from trapped enhancer-dependent GAL4VP16 expression because crossing with different driver fish led to unique expression patterns. The second class of DsRedExDR expression was likely caused by low-level GAL4VP16 expression mediated by the basal promoter activity in the transgene. GAL4VP16-positive F1 embryos except TKBAsi-GAL4VP16#14m did not survive beyond 5 dpf. Note that the embryos showing the most intense reporter expression levels were often already malformed (B,E,N,P,Q).