Imprecise excision of the P-element from VmatSH0459. Most of the transposon is removed including the white w eye marker. 51 base pairs in the 6th and last coding exons remain.
Under standard culture conditions, less than 1% of homozygotes survive to adulthood, but if the density of the cultures is reduced, more homozygotes eclose and survive to adulthood.
Homozygous females can give rise to a few adult progeny. Only 24% of homozygous males produce adult progeny when mated with wild-type females.