Golgi apparatus somehow replicate during the normal course of cytokinesis and in gamete formation so that their continuity is assured. Division of the Golgi apparatus or its parts was assumed for many years but usually without adequate documentation. The concept of fusion of endoplasmic reticulum — or nuclear envelope-derived vesicles within a zone of exclusion (Golgi apparatus matrix) or organizational field of a pre-existing stack or prestage (Morré et al., 1971c; Fig. 9.1) has subsequently been revisited and has emerged as a fundamental feature of Golgi apparatus ontogeny (Glick, 2002; Shorter and Warren, 2002).
Golgi apparatus stacks must multiply, since the original Golgi apparatus compliment is reproducibly maintained as cells divide. For example, at cytokinesis, two pools of Golgi membranes normally appear on opposite sides of the nucleus (Shima et al., 1998; Seemann et al., 2002). A functional Golgi apparatus is required for the membrane-fusion events either between the inner leaflets of the plasma membrane or between vesicles and the plasma membrane that are necessary to seal the intercellular bridge when cells divide (Robinson and Spudich, 2000). This requirement is especially evident in plant cells where a prominent cell plate is formed by fusion of Golgi apparatus vesicles (Whaley et al., 1966; Fig. 9.2) as well as for furrow formation at the end of cytokinesis in non-walled cells. Reorientation of the centro-some/Golgi at cytokinesis may reflect the need to direct delivery of vesicles toward the intercellular bridge and ensure plasma membrane sealing during cell separation.
KeywordsEndoplasmic Reticulum Golgi Apparatus Nuclear Envelope Proximal Pole Intercellular Bridge
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