Egg chambers containing cos52B7 follicle cell clones contain extra polar cells surrounded by extra border cells.
Homozygous clones induced in the follicle cells result in defects in border cell development; extra border cells are produced. Most of these extra border cells migrate in between the nurse cells to some extent, but are often ectopically located. Ectopic polar follicle cells are also produced.
Selected as: a mutation that causes defects in border cell migration when homozygous clones are induced in the follicle cells.