Golgi biogenesis in Toxoplasma gondii.
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.
Pelletier
Laurence
L
Department of Cell Biology, Ludwig Institute for Cancer Research, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Stern
Charlene A
CA
Pypaert
Marc
M
Sheff
David
D
Ngô
Huân M
HM
Roper
Nitin
N
He
Cynthia Y
CY
Hu
Ke
K
Toomre
Derek
D
Coppens
Isabelle
I
Roos
David S
DS
Joiner
Keith A
KA
Warren
Graham
G
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