border follicle cell A follicle cell that migrates from the anterior pole of the egg chamber, between the nurse cells, to the anterior of the oocyte where they participate in formation of the micropyle. About 6-10 border cells per egg chamber migrate as a tightly associated cluster. Tomasz Adamusiak A follicle cell that migrates from the anterior pole of the egg chamber, between the nurse cells, to the anterior of the oocyte where they participate in formation of the micropyle. About 6-10 border cells per egg chamber migrate as a tightly associated cluster. cell type