Fig. 7. foi regulates shg at the post-transcriptional level. (A-D,F-H) Confocal sections of stage 15-16 embryos immunostained with -ZFH-1 (SGPs, red) and -DCAD2 (DE-cadherin, green). The right-hand panels show DE-cadherin channel alone. Gonads and germ cells are indicated with broken lines and asterisks, respectively. Both wild-type (A) and wild-type, tub-DE-cad (B) embryos exhibit high levels of DE-cadherin in the gonad. (C) shg^R69 mutant gonad lacking most DE-cadherin expression, but with some -DCAD2 immunoreactivity in large ring-like structures that fail to co-localize with armadillo (Jenkins et al., 2003). (D) shg^R69; tub-DE-cad gonad with high levels of DE-cadherin concentrated around germ cells where they are ensheathed by SGPs. (E) Confocal section of a stage 15 embryo, in which tubulin-GAL4 drives expression of UAS-mCD8::GFP, immunolabeled with -GFP (green) and -EYA (SGPs, red). The SGPs express less GFP than the surrounding mesodermal cells. (F,H) foi^20.71, tub-DE-cad. DE-cadherin is most often seen as weak punctae between germ cells (F) or is completely absent in gonads. In some embryos (H), more DE-cadherin protein is detected. (G) Little or no DE-cadherin expression is observed in the SGPs of foi^20.71 mutant gonads. msSGPs (posterior/right in this gonad) still express DE-cadherin in foi mutants, as has previously been reported (Jenkins et al., 2003). (I-L) Confocal sections of stage 15-16 embryos, labeled by fluorescent in situ hybridization to reveal shg RNA (red) and immunolabeled with -VAS (green, germ cells). Right-hand images represent shg RNA alone. Very little shg RNA immunoreactivity is observed in shg^R69 mutant gonads (I), but shg RNA is restored in shg^R69; tub-DE-cad (J). tub-DE-cad fails to restore shg RNA expression to most foi^20.71 mutant gonads (K), but a minority have shg RNA restored (L). Scale bar: 10 µm.