Patterns of cell division in imaginal discs of Drosophila

A transmission electron microscopic study of cell division in serially sectioned imaginal discs of early third instar fruitfly larvae revealed that mitotic cells maintain a relationship with the basal surface of the disc through thin cytoplasmic extensions abutting on vesicular material. Two patterns of cell division were discerned. In one, cell divisions were isolated and usually found near the peripodial membrane-disc epithelium junction; in the other, cell divisions were clustered. Observations on cell death and cell division in the peripodial membrane are also reported.