Fig. 2. Downregulation of the expression of dpp targets in lglts3 mutant embryos. (A,D,F,H,J) Wild-type embryos; (C,E,G,I,K) lglts3 homozygous embryos reared at 29°C; (B) tkv7 homozygous embryo. (A-C) In situ hybridizations of whole-mount embryos probed with a DIG-labeled zipper cDNA. The views are focused on one of the two LE cells rows (arrowheads) where zip transcript accumulates in a wild-type embryo at the onset of dorsal closure (A) but fails to accumulate either in a tkv7 homozygous embryo (B) or in a lglts3 homozygous embryo at 29°C (C). as, amnioserosa; ec, lateral ectoderm; h, head. (D,E) In situ hybridizations of whole-mount embryos probed with a DIG-labeled dpp cDNA. (D) In a stage 13 wild-type embryo, dpp is expressed in the LE cells (arrowhead), as well as in subsets of other cells such as those in the visceral mesoderm. (E) A lglts3 mutant embryo at the same stage expresses dpp in the LE cells (arrowhead), as does the wild-type embryo. Note the lower expression of dpp in the PS7 visceral mesoderm. (F,G) In situ hybridizations of whole-mount embryos probed with a DIG-labeled lab cDNA. lab expression was no longer detected in a lglts3 mutant embryo (arrowhead). The most extreme phenotype, with almost complete absence of lab expression, is shown here. Persistence of a labeling in the intercalary segment should be noted in mutant embryos. (H,I) Tin is expressed in the cardial cells in wild-type embryos and absent from most of the cardial cells in mutant embryos (arrowheads). (J,K) The same situation prevails in the case of Eve expression. The anti-Eve antibody labels a subset of pericardial cells and of dorsal muscles precursors. For all embryos shown, anterior is leftwards and the dorsal side is in focus. The genotypes are mentioned in the lower left and the probe or the antibody used in the lower right of each panel.