Fig 3. The end of nuclear multiplication and formation of daughter cells.

(A) Structures and organelles involved in cytokinesis start forming during early nuclear cycles. Proteins of the IMC and the rhoptries start organizing around the centriolar plaque in cells with nuclei numbers as low as four and develop into larger structures as nuclear multiplication progresses. (B) Daughter cells are formed during segmentation. Concomitant to daughter cell formation, the nuclei are divided in a final, semisynchronous round of nuclear division. One pair of rhoptries associates with the apical end of the developing daughter cells. Segmentation commences when the plasma membrane (PM) starts invaginating. During segmentation, the IMC, which sits below the PM and originates from the apical end, starts enveloping the emerging daughter cell alongside the PM, with the basal complex localizing to the leading edge of the IMC. Concurrently to the expansion of the IMC, subpellicular microtubules start developing from the apical end of the emerging daughter cells. At the end of segmentation, the daughter cells now containing all necessary organelles are pinched off a remnant body containing the food vacuole.