Fig. 2.

Drosophila Hsc20 piggyBac insertion mutants arrest growth as third instar larvae. a Hsc20 ^f2457 /TM3, Kr-GFP, Sb (f2457/+) flies (GFP is green fluorescent protein) laid eggs on agar plates supplied with yeast; embryos and larvae were visualized with a fluorescent microscope and homozygous mutants (f2457/f2457) were identifiable from the absence of fluorescent signal. Homozygous mutant larvae failed to grow during the third instar. b Actin-Gal4-driven genetic rescue of homozygous f2457/f2457 mutants by virtue of the upstream activating sequence (UAS) elements present in the PBac{WH}l(3)72Do ^f02457 transgene, which permit expression of the endogenous Hsc20 gene following activation by Gal4. N depicts the total number of flies scored. The rescue is not always complete, as many flies complete metamorphosis but fail to eclose from their pupal cases. UAS elements are absent from the PBac{PB}l(3)72Do ^c05018 transgene, which serves as a control for this experiment. FRT flippase recombinase target