slbo reporter is first detected in border follicle cells at oogenesis stage S9. Expression is detected at stage 10A in border cells, centripally migrating follicle cells, and nurse follicle cells. Levels are high in the centripetally migrating follicle cells at oogenesis stage S10A and then decrease in stage S10B when ct levels become high. By stage S11, reporter expression persists only in the follicle cells at the leading edge of centripetal migration, cells that are also marked by ct and eya and at the posterior pole. In the border cell cluster slbo reporter is expressed in both the inner polar cells and the outer border cell rosette where ct can be seen at well.