title: Golgi biogenesis in Toxoplasma gondii.
abstract: Two models have been put forward to explain the growth of new Golgi during the cell cycle. The first suggests that a new Golgi grows out of the endoplasmic reticulum by de novo synthesis. The second suggests that a pre-existing Golgi is needed for the growth of a new one, that is, the Golgi is an autonomously replicating organelle. To resolve this issue, we have exploited the simplicity of the apicomplexan parasite Toxoplasma gondii, which has only a single Golgi stack. Here we show, by using video fluorescence microscopy and three-dimensional reconstructions of serial thin sections, that the Golgi grows by a process of lateral extension followed by medial fission. Further fission leads to the inheritance by each daughter of a pair of Golgi structures, which then coalesce to re-form a single Golgi. Our results indicate that new Golgi grow by autonomous duplication and raise the possibility that the Golgi is a paired structure that is analogous to centrioles.
authors.affiliation: Department of Cell Biology, Ludwig Institute for Cancer Research, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
authors.forename: Laurence
authors.initials: L
authors.lastname: Pelletier
authors.forename: Charlene A
authors.initials: CA
authors.lastname: Stern
authors.forename: Marc
authors.initials: M
authors.lastname: Pypaert
authors.forename: David
authors.initials: D
authors.lastname: Sheff
authors.forename: Huân M
authors.initials: HM
authors.lastname: Ngô
authors.forename: Nitin
authors.initials: N
authors.lastname: Roper
authors.forename: Cynthia Y
authors.initials: CY
authors.lastname: He
authors.forename: Ke
authors.initials: K
authors.lastname: Hu
authors.forename: Derek
authors.initials: D
authors.lastname: Toomre
authors.forename: Isabelle
authors.initials: I
authors.lastname: Coppens
authors.forename: David S
authors.initials: DS
authors.lastname: Roos
authors.forename: Keith A
authors.initials: KA
authors.lastname: Joiner
authors.forename: Graham
authors.initials: G
authors.lastname: Warren
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002455:Cell Division; D005347:Fibroblasts / Q000469:parasitology; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D018715:Microscopy, Video; D051381:Rats; D014122:Toxoplasma / Q000166:cytology* / Q000235:genetics / Q000648:ultrastructure; D019076:Transgenes / Q000235:genetics