Transheterozygotes are male and female sterile, exhibit brain and meiotic defects. Males fail to fold wings back at 25oC and testes exhibit great variation in nuclear size at the postmeiotic onion stage and a large number of disorganised Nebenkern per nucleus. Adults exhibit short bristles at 18oC. Homozygous females are poorly fertile. Transheterozygotes with hsk1 are viable but female sterile. Transheterozygotes with noose3 exhibit bristle duplication.
Phenotype assayed in trans with a multiple mutant chromosome carrying mutations of polo, mgr, asp, stg and gnu.