In egg chambers containing phm^FT59 whole epithelial homozygous mutant clones, migration of the border cells (BCs) is severely disrupted. In wild-type egg chambers BC clusters reach the border between the nurse cells and the oocyte at stage 10A of oogenesis. At the same developmental stage, the majority of BC clusters in egg chambers containing whole epithelial homozygous mutant clones do not initiate the migration, and retain their position at the most anterior end of the egg chambers. Importantly, BC migration progresses normally in egg chambers that contain even a small number (8-15%) of wild-type cells.

A failure in the production of differentiated cuticle structures is observed in homozygous phm^FT59 mutant embryos.

Compared to wild-type, no increase in degeneration is observed in ovaries after induction of germline clones of homozygous phm^FT59 cells. Eggs laid by females carrying homozygous mutant germline clones lay eggs that produce hatching larvae at a rate similar to controls. Border cell migration appears normal when the germline is mutant for phm^FT59.