Transheterozygotes are adult lethal, females are poorly fertile, individuals are viable at 18oC, exhibit brain defects but no meiotic defects. Transheterozygotes with stg2 are semi-lethal, few flies emerge then die. Homozygous adults eclose and die in food.
Phenotype assayed in trans with a multiple mutant chromosome carrying mutations of polo, mgr, asp, stg and gnu.