The cardial cells (CCs) are unevenly distributed in mutant embryos: hemisegments having localised increases or decreases in CC number, occasional enlarged CC nuclei and CCs that are misaligned either with other CCs within a hemisegment or with their counterparts across the dorsal midline are seen.
The number of SELK neurons is normal in jumu06439 mutant animals.
Homozygous embryos occasionally show duplication of the RP2 neuron (expressivity of the phenotype is 4%).
jumu06439 wing disc cell clones induced at late embryonic to early larval stages are much smaller than their sibling clones when examined in late third-instar larvae. Small mutant clones are detected in adult wing blades, but no mutant cells are found in the wing margin or bristles on the notum. In eye discs, small mutant clones are formed in the regions anterior to the morphogenetic furrow, while no mutant clones are detected posterior to the morphogenetic furrow or in the adult eye.
Approximately 95% of jumu06439 embryos are defective in head involution, displaying an anterior open phenotype. Furthermore, about 35% of these flies show a defect in dorsal closure in addition the head involution defect. Incomplete germ band retraction is found in 20% of embryos. In jumu06439 embryos, the dorsal epidermal cells only partially elongate. These embryos exhibit loss of a large number of both CNS and PNS neurons. Occasionally, all or most of the CNS neurons in a hemisegment are lost.