Tissue-specific control of transgene expression. Driven by pou4f3:gal4, mCherry (A,A′) is specifically expressed in the RGC layer (B,B′) of 4dpf pou4f3:gal4;uas:mCherry-f2a-Cdc42^WT embryos. A′-C′ are magnified images taken from the boxed regions in A-C. Scale bars = 20 µm.

Antibody validation of transgene expression. A: Myc colocalization with mCherry expression in heat-shocked hsp70l:gal4;uas:mCherry-F2A-myc-Cdc42^WT embryos. B: No signal for mCherry or myc was detected in uas:mCherry-F2A-myc-Cdc42^WT transgenics missing the hsp70l:gal4 transgene. C: Rac1 antibody staining in ptf1a:gal4;uas:gfp-f2a-Rac1^WT embryos. D: Myc colocalization with mCherry expression in heat-shocked hsp70l:gal4;uas:mCherry-F2A-myc-RhoA^WT retinae. E: No signal for mCherry or myc was detected in uas:mCherry-F2A-myc-RhoA^WT transgenics missing the hsp70l:gal4 transgene. Scale bar = 10µm.

Construct expression and phenotypes of GAL4-positive and -negative embryos of Cdc42 transgenics. Transgenic F1s were outcrossed to hsp70l:gal4 zebrafish, and cmlc2:egfp⁺ embryos were heat-shocked at ~26 hpf and imaged at ~50 hpf. Gross morphology, transgene expression, and lens structure of hsp70l:gal4-positive and -negative (A) Cdc42^WT, (B) Cdc42^CA (C) Cdc42^T17N, and (D) Cdc42^F37A embryos. Transgene expression was strong and ubiquitous following heat shock, and cryosections reveal lens fiber organization defects in all induced transgenics. Scale bar = 25µm.

Construct expression and phenotypes of GAL4-positive and -negative embryos of Rac transgenics. Transgenic F1s were outcrossed to hsp70l:gal4 zebrafish, and cmlc2:egfp⁺ embryos were heat-shocked at ~26 hpf and imaged at ~50 hpf. Gross morphology, transgene expression, and lens structure of hsp70l:gal4-positive and -negative (A) Rac1^WT, (B) Rac1^CA, and (C) Rac1^DN embryos. Transgene expression was strong and ubiquitous following heat shock, and cryosections reveal lens fiber organization defects in Rac^CA and Rac^DN induced transgenics. Scale bar = 25µm.

Construct expression and phenotypes of GAL4-positive and -negative embryos of Rho transgenics. Transgenic F1s were outcrossed to hsp70l:gal4 zebrafish, and cmlc2:egfp⁺ embryos were heat-shocked at ~26 hpf and imaged at ~50 hpf. Gross morphology, transgene expression, and lens structure of hsp70l:gal4-positive and -negative (A) RhoA^WT, (B) RhoA^CA, and (C) RhoA^DN embryos. Transgene expression was strong and ubiquitous following heat shock, and cryosections reveal lens fiber organization defects in all induced transgenics. Scale bar = 25µm.