|
|
||||||||
Physiology and Growth |
Department of Botany, University of Georgia, Athens, GA 30602 7271, USA1
Author for correspondence: Michelle Momany. Tel: +1 706 542 2014. Fax: +1 706 542 1805. e-mail: momany{at}dogwood.botany.uga.edu
When the spores of filamentous fungi break dormancy, nuclear division is accompanied by a series of ordered morphological events including the switch from isotropic to polar growth, the emergence of a second germ tube from the conidium and septation. Correlation of these morphological events with nuclear number allows them to serve as duplication cycle landmarks. Early duplication cycle landmarks have been characterized in Aspergillus nidulans, but not in other filamentous fungi. To learn more about duplication cycle control in filamentous fungi, a study was undertaken to compare the timing of landmarks in Aspergillus fumigatus and A. nidulans. Nuclear duplication took approximately 45 min in A. fumigatus, with mitosis occupying roughly 5% of this period. Under the same conditions, nuclear duplication in A. nidulans took approximately 60 min, with mitosis occupying roughly 4% of this period. In A. fumigatus the isotropic to polar switch preceded the first mitosis in 22% of cells, while in A. nidulans the isotropic to polar switch did not occur until after the first mitosis. In both A. fumigatus and A. nidulans the earliest emergence of a second germ tube from the conidium occurred after the third mitotic division. However, by the fifth mitosis only 19% of A. fumigatus conidia had a second germ tube, compared to 98% of A. nidulans conidia. In both A. fumigatus and A. nidulans, formation of the first septum occurred after the fourth mitotic division. In all experiments a few cells lagged behind the others in nuclear number. In this delayed group, it was common to see landmark events at an earlier mitotic division. Differences in nuclear number when identical landmarks occur in A. fumigatus versus A. nidulans, and uncoupling of mitotic division and landmarks in delayed cells suggest that nuclear division and morphogenesis lie in parallel pathways, perhaps coordinated by checkpoints.
Keywords: cell cycle, mitosis, morphogenesis
a Present address: Cereon Genomics, LLC, Discovery, 45 Sidney Street, Cambridge, MA 02139, USA.
This article has been cited by other articles:
![]() |
J. R. Fortwendel, K. K. Fuller, T. J. Stephens, W. C. Bacon, D. S. Askew, and J. C. Rhodes Aspergillus fumigatus RasA Regulates Asexual Development and Cell Wall Integrity Eukaryot. Cell, September 1, 2008; 7(9): 1530 - 1539. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Li, L. Zhang, D. Wang, H. Zhou, H. Ouyang, J. Ming, and C. Jin Deletion of the msdS/AfmsdC gene induces abnormal polarity and septation in Aspergillus fumigatus Microbiology, July 1, 2008; 154(7): 1960 - 1972. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Bhabhra, D. L. Richie, H. S. Kim, W. C. Nierman, J. Fortwendel, J. P. Aris, J. C. Rhodes, and D. S. Askew Impaired Ribosome Biogenesis Disrupts the Integration between Morphogenesis and Nuclear Duplication during the Germination of Aspergillus fumigatus Eukaryot. Cell, April 1, 2008; 7(4): 575 - 583. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Breakspear and M. Momany Aspergillus nidulans Conidiation Genes dewA, fluG, and stuA Are Differentially Regulated in Early Vegetative Growth Eukaryot. Cell, September 1, 2007; 6(9): 1697 - 1700. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. W. Martin, L. M. Douglas, and J. B. Konopka Cell Cycle Dynamics and Quorum Sensing in Candida albicans Chlamydospores Are Distinct from Budding and Hyphal Growth Eukaryot. Cell, July 1, 2005; 4(7): 1191 - 1202. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D. Harris Morphogenesis in germinating Fusarium graminearum macroconidia Mycologia, July 1, 2005; 97(4): 880 - 887. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Momany, R. Lindsey, T. W. Hill, E. A. Richardson, C. Momany, M. Pedreira, G. M. Guest, J. F. Fisher, R. B. Hessler, and K. A. Roberts The Aspergillus fumigatus cell wall is organized in domains that are remodelled during polarity establishment Microbiology, October 1, 2004; 150(10): 3261 - 3268. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Lin, C. Momany, and M. Momany SwoHp, a Nucleoside Diphosphate Kinase, Is Essential in Aspergillus nidulans Eukaryot. Cell, December 1, 2003; 2(6): 1169 - 1177. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Bennion, C. Park, M. Fuller, R. Lindsey, M. Momany, R. Jennemann, and S. B. Levery Glycosphingolipids of the model fungus Aspergillus nidulans: characterization of GIPCs with oligo-{alpha}-mannose-type glycans J. Lipid Res., November 1, 2003; 44(11): 2073 - 2088. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Lin and M. Momany The Aspergillus nidulans swoC1 Mutant Shows Defects in Growth and Development Genetics, October 1, 2003; 165(2): 543 - 554. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Knechtle, F. Dietrich, and P. Philippsen Maximal Polar Growth Potential Depends on the Polarisome Component AgSpa2 in the Filamentous Fungus Ashbya gossypii Mol. Biol. Cell, October 1, 2003; 14(10): 4140 - 4154. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. D. Shaw, C. Momany, and M. Momany AspergillusnidulansswoF Encodes an N-Myristoyl Transferase Eukaryot. Cell, April 1, 2002; 1(2): 241 - 248. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Momany, E. A. Richardson, C. Van Sickle, and G. Jedd Mapping Woronin body position in Aspergillus nidulans Mycologia, March 1, 2002; 94(2): 260 - 266. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Momany, J. Zhao, R. Lindsey, and P. J. Westfall Characterization of the Aspergillus nidulans Septin (asp) Gene Family Genetics, March 1, 2001; 157(3): 969 - 977. [Abstract] [Full Text] |
||||
![]() |
P. J. Westfall and M. Momany Aspergillus nidulans Septin AspB Plays Pre- and Postmitotic Roles in Septum, Branch, and Conidiophore Development Mol. Biol. Cell, January 1, 2002; 13(1): 110 - 118. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |