![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Vol. 19, Issue 7, 3163-3178, July 2008
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
*Department of Biology, Lineberger Comprehensive Cancer Center, and Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
Submitted October 24, 2007;
Revised April 1, 2008;
Accepted April 29, 2008
Monitoring Editor: Tim Stearns
In animal cells, centrosomes nucleate microtubules that form polarized arrays to organize the cytoplasm. Drosophila presents an interesting paradox however, as centrosome-deficient mutant animals develop into viable adults. To understand this discrepancy, we analyzed behaviors of centrosomes and microtubules in Drosophila cells, in culture and in vivo, using a combination of live-cell imaging, electron microscopy, and RNAi. The canonical model of the cycle of centrosome function in animal cells states that centrosomes act as microtubule-organizing centers throughout the cell cycle. Unexpectedly, we found that many Drosophila cell-types display an altered cycle, in which functional centrosomes are only present during cell division. On mitotic exit, centrosomes disassemble producing interphase cells containing centrioles that lack microtubule-nucleating activity. Furthermore, steady-state interphase microtubule levels are not changed by codepleting both 
-tubulins. However, -tubulin RNAi delays microtubule regrowth after depolymerization, suggesting that it may function partially redundantly with another pathway. Therefore, we examined additional microtubule nucleating factors and found that Mini-spindles, CLIP-190, EB1, or dynein RNAi also delayed microtubule regrowth; surprisingly, this was not further prolonged when we codepleted -tubulins. Taken together, these results modify our view of the cycle of centrosome function and reveal a multi-component acentrosomal microtubule assembly pathway to establish interphase microtubule arrays in Drosophila.
Address correspondence to: Stephen Rogers (srogers{at}bio.unc.edu)
Abbreviations used: MT, microtubules; HTM, high-throughput microscopy; MTOC, microtubule-organizing center; PCM, pericentriolar material; NEB, nuclear envelope breakdown; Tub, gamma tubulin; +TIP, plus–end tracking protein; Msps, mini-spindles; DHC, dynein heavy chain; RNAi, RNA interference.
Related articles in Mol. Biol. Cell:
This article has been cited by other articles:
|
|
 |
|
  S. Moutinho-Pereira, A. Debec, and H. Maiato Microtubule Cytoskeleton Remodeling by Acentriolar Microtubule-organizing Centers at the Entry and Exit from Mitosis in Drosophila Somatic Cells Mol. Biol. Cell, June 1, 2009; 20(11): 2796 - 2808. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Groen, T. J. Maresca, J. C. Gatlin, E. D. Salmon, and T. J. Mitchison Functional Overlap of Microtubule Assembly Factors in Chromatin-Promoted Spindle Assembly Mol. Biol. Cell, June 1, 2009; 20(11): 2766 - 2773. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. Guerin and S. G. Kramer RacGAP50C directs perinuclear {gamma}-tubulin localization to organize the uniform microtubule array required for Drosophila myotube extension Development, May 1, 2009; 136(9): 1411 - 1421. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. C. Rogers, N. M. Rusan, D. M. Roberts, M. Peifer, and S. L. Rogers The SCFSlimb ubiquitin ligase regulates Plk4/Sak levels to block centriole reduplication J. Cell Biol., January 26, 2009; 184(2): 225 - 239. [Abstract] [Full Text] [PDF]
|
|
