Lethality acts in the pharate adult and adult stages.
Lethality occurs at pharate adult to adult stages. Embryos exhibit abnormal morphology of neurons. Transheterozygotes with stg4 or stg01235 produce adult escapers that lack scutellars and many other bristles, have rough eyes and occasionally lack a haltere or have notched wings.
May be revertable under Δ2-3-induced element mobilization conditions.