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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) shgR69
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) shgR69;
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) foi20.71, 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
foi20.71 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 shgR69 mutant gonads (I),
but shg RNA is restored in shgR69;
tub-DE-cad (J). tub-DE-cad fails to restore shg RNA
expression to most foi20.71 mutant gonads (K), but a
minority have shg RNA restored (L). Scale bar: 10 µm.
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