sepB: An Aspergillus nidulans gene involved in chromosome segregation and the initiation of cytokinesis

S. D. Harris, J. E. Hamer

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

In Aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. This has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. Conditional mutations in the sepB gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepB3 mutants demonstrate transient delays in M-phase, accumulate aneuploid nuclei and show defects in chromosome segregation. Molecular analysis of the sepB gene reveals that it is essential and possesses limited similarity to the CTF4 gene of Saccharomyces cerevisiae. Using temperature-shift analysis we show that sepB is required after the first nuclear division but before the onset of cytokinesis. A failure to execute the sepB function results in a block to nuclear division and leads to cell death at a time when wild-type cells would be undergoing cytokinesis. Finally, we demonstrate that sepB is also required for the uninucleate cell divisions of developing conidiophores. Our results suggest that sepB3 mutants accumulate specific nuclear defects that do not arrest mitosis, but block the initiation of septum formation. Thus, proper chromosome segregation and a functional sepB gene are required to initiate cytokinesis.

Original languageEnglish (US)
Pages (from-to)5244-5257
Number of pages14
JournalEMBO Journal
Volume14
Issue number21
StatePublished - Jan 1 1995

Fingerprint

Cell Nucleus Division
Aspergillus nidulans
Chromosome Segregation
Cytokinesis
Aspergillus
Chromosomes
Genes
Cell Division
Defects
Temperature
Fungal Spores
Essential Genes
Aneuploidy
Cell death
Spores
Mitosis
Yeast
Saccharomyces cerevisiae
Cell Death
Cells

Keywords

  • Aspergillus
  • Cell cycle
  • Cytokinesis
  • Nuclear division
  • Septation

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

Cite this

sepB : An Aspergillus nidulans gene involved in chromosome segregation and the initiation of cytokinesis. / Harris, S. D.; Hamer, J. E.

In: EMBO Journal, Vol. 14, No. 21, 01.01.1995, p. 5244-5257.

Research output: Contribution to journalArticle

@article{a5f7bf0d8b934a7f80e8373267985c8a,
title = "sepB: An Aspergillus nidulans gene involved in chromosome segregation and the initiation of cytokinesis",
abstract = "In Aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. This has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. Conditional mutations in the sepB gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepB3 mutants demonstrate transient delays in M-phase, accumulate aneuploid nuclei and show defects in chromosome segregation. Molecular analysis of the sepB gene reveals that it is essential and possesses limited similarity to the CTF4 gene of Saccharomyces cerevisiae. Using temperature-shift analysis we show that sepB is required after the first nuclear division but before the onset of cytokinesis. A failure to execute the sepB function results in a block to nuclear division and leads to cell death at a time when wild-type cells would be undergoing cytokinesis. Finally, we demonstrate that sepB is also required for the uninucleate cell divisions of developing conidiophores. Our results suggest that sepB3 mutants accumulate specific nuclear defects that do not arrest mitosis, but block the initiation of septum formation. Thus, proper chromosome segregation and a functional sepB gene are required to initiate cytokinesis.",
keywords = "Aspergillus, Cell cycle, Cytokinesis, Nuclear division, Septation",
author = "Harris, {S. D.} and Hamer, {J. E.}",
year = "1995",
month = "1",
day = "1",
language = "English (US)",
volume = "14",
pages = "5244--5257",
journal = "EMBO Journal",
issn = "0261-4189",
publisher = "Nature Publishing Group",
number = "21",

}

TY - JOUR

T1 - sepB

T2 - An Aspergillus nidulans gene involved in chromosome segregation and the initiation of cytokinesis

AU - Harris, S. D.

AU - Hamer, J. E.

PY - 1995/1/1

Y1 - 1995/1/1

N2 - In Aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. This has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. Conditional mutations in the sepB gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepB3 mutants demonstrate transient delays in M-phase, accumulate aneuploid nuclei and show defects in chromosome segregation. Molecular analysis of the sepB gene reveals that it is essential and possesses limited similarity to the CTF4 gene of Saccharomyces cerevisiae. Using temperature-shift analysis we show that sepB is required after the first nuclear division but before the onset of cytokinesis. A failure to execute the sepB function results in a block to nuclear division and leads to cell death at a time when wild-type cells would be undergoing cytokinesis. Finally, we demonstrate that sepB is also required for the uninucleate cell divisions of developing conidiophores. Our results suggest that sepB3 mutants accumulate specific nuclear defects that do not arrest mitosis, but block the initiation of septum formation. Thus, proper chromosome segregation and a functional sepB gene are required to initiate cytokinesis.

AB - In Aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. This has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. Conditional mutations in the sepB gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepB3 mutants demonstrate transient delays in M-phase, accumulate aneuploid nuclei and show defects in chromosome segregation. Molecular analysis of the sepB gene reveals that it is essential and possesses limited similarity to the CTF4 gene of Saccharomyces cerevisiae. Using temperature-shift analysis we show that sepB is required after the first nuclear division but before the onset of cytokinesis. A failure to execute the sepB function results in a block to nuclear division and leads to cell death at a time when wild-type cells would be undergoing cytokinesis. Finally, we demonstrate that sepB is also required for the uninucleate cell divisions of developing conidiophores. Our results suggest that sepB3 mutants accumulate specific nuclear defects that do not arrest mitosis, but block the initiation of septum formation. Thus, proper chromosome segregation and a functional sepB gene are required to initiate cytokinesis.

KW - Aspergillus

KW - Cell cycle

KW - Cytokinesis

KW - Nuclear division

KW - Septation

UR - http://www.scopus.com/inward/record.url?scp=0028834279&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028834279&partnerID=8YFLogxK

M3 - Article

C2 - 7489714

AN - SCOPUS:0028834279

VL - 14

SP - 5244

EP - 5257

JO - EMBO Journal

JF - EMBO Journal

SN - 0261-4189

IS - 21

ER -