Expression of UAS-hmgcr but not UAS-hh or UAS-hh-N in the nervous system can attract germ cells.
(A-C) Stage 14 embryos stained for Vasa to mark germ cells (brown). The driver elav-GAL4 activates UAS expression in the nervous system. Note that UAS-hmgcr (C) expression in the nervous system leads to attraction of germ cells, while expression of UAS-hh (A) or the more active UAS-hhN (B) has no effect on germ cell migration. Embryos are oriented anterior to left, dorsal up.
(D) Quantification of hh misexpression phenotypes. Percentage of stage 14-16 embryos with indicated number of germ cells outside of the embryonic gonads. Flies homozygous for the mesoderm driver, twist-Gal4, or CNS driver, elav-Gal4, were crossed with flies homozygous for the UAS transgene. Embryos containing the UAS-hh and twist-Gal4 transgenes alone were used as a control to indicate the normal fidelity of germ cell migration.