Embryos derived from pip¹/pip² or heterozygous females expressing pip^ST2.Scer\UAS under the control of Scer\GAL4²⁵ show strong ventralisation, producing cuticles with rings of ventral denticle material. The orientation of gastrulation in these embryos is variable and they show muscle movement. Embryos derived from pip¹/pip² females expressing pip^ST2.Scer\UAS under the control of Scer\GAL4²⁴¹ show gastrulation movements that are inverted with respect to the intrinsic orientation of the eggshell. The most ventral structures differentiated by most of these embryos are Filzkorper, although some embryos develop ventral denticle material. Embryos derived from pip¹/pip² females expressing pip^ST2.Scer\UAS under the control of Scer\GAL4^DE1 form a ventral furrow invagination only at the posterior end. These embryos form rings of denticles at the posterior end.