The polyubiquitin gene is essential for meiosis in fission yeast

Related Experiment Video

Updated: Oct 18, 2026

Use of Time-Lapse Microscopy and Stage-Specific Nuclear Depletion of Proteins to Study Meiosis in S. cerevisiae
07:48

Use of Time-Lapse Microscopy and Stage-Specific Nuclear Depletion of Proteins to Study Meiosis in S. cerevisiae

Published on: October 11, 2022

K Okazaki1, H Okayama, O Niwa

  • 1Kazusa DNA Research Institute, 1532-3 Yana Kisarazu, Chiba, 292-0812, Japan. kokazaki@kazusa.or.jp

Experimental Cell Research
|January 7, 2000
PubMed

Insights

A novel mutant of Schizosaccharomyces pombe shows sporulation defects due to a mutation in the polyubiquitin gene ubi4(+). This highlights the critical role of ubiquitination in maintaining spindle pole body integrity during meiosis.

Area of Science:

  • Cell Biology
  • Genetics
  • Molecular Biology

Background:

  • Sporulation is a crucial process in the life cycle of many organisms, including yeast.
  • Meiosis involves complex cellular events regulated by precise molecular mechanisms.
  • Spindle pole bodies (SPBs) are essential structures for organizing the spindle apparatus during cell division.

Purpose of the Study:

  • To identify and characterize novel mutants affecting sporulation in Schizosaccharomyces pombe.
  • To elucidate the molecular basis of meiotic defects observed in a sporulation-deficient mutant.
  • To investigate the role of the polyubiquitin gene ubi4(+) in meiotic progression and SPB integrity.

Main Methods:

  • Isolation and characterization of a sporulation-deficient mutant in Schizosaccharomyces pombe.
  • Genetic complementation analysis using the polyubiquitin gene ubi4(+).
  • Gene sequencing to identify the causative mutation within ubi4(+).
  • Phenotypic analysis of ubi4(+) disruption mutants.
  • Time-lapse microscopy to observe meiotic progression and SPB dynamics.

Main Results:

  • A novel mutant exhibited meiotic abortion with defects in chromosome segregation, abnormal spindles, and disintegrated SPBs.
  • Complementation with the ubi4(+) gene and identification of a mutation within its initiation codon confirmed ubi4(+) as the responsible gene.
  • Disruption of ubi4(+) recapitulated the observed meiotic defects.
  • While ubi4(+) mRNA levels increased during meiosis, total ubiquitin levels rose only slightly, indicating ubiquitin consumption.
  • Pre-meiotic depletion of ubiquitin in ubi4 mutant cells correlated with meiotic abortion.

Conclusions:

  • The polyubiquitin gene ubi4(+) is essential for successful sporulation in Schizosaccharomyces pombe.
  • Ubiquitination plays a critical role in maintaining SPB integrity during meiotic divisions.
  • Shortage of ubiquitin, supplied by ubi4(+), leads to meiotic abortion, underscoring the importance of ubiquitination pathways in meiosis.

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