Hand is dispensable for initial midgut differentiation. (A-F) show embryos stained for β3Tubulin (red channel, mesodermal derivatives), and βGalactosidase (green channel, balancer staining, marked with double arrows). Embryos with mutated hand gene, either induced by homologues recombination (handKO) or by a deficiency (DF(2L)Exel7046) reveal normal formation of visceral mesoderm and a differentiated gut at later stages (D). A, C and E show wildtype embryos for comparison. A and B show stage 10 embryos from a lateral view, C and D stage 16/17 embryos from a dorsolateral view and E and F stage 13/14 embryo from a dorsal view. The embryo shown in F reveals weak autofluorescence do to overexposure of the green channel to clearly demonstrate the absence of the balancer.