Related Experiment Video
Updated: Aug 9, 2026
Use of Time-Lapse Microscopy and Stage-Specific Nuclear Depletion of Proteins to Study Meiosis in S. cerevisiae
Published on: October 11, 2022
Negative control for the initiation of meiosis in Schizosaccharomyces pombe
1Laboratory of Molecular Genetics, Institute of Medical Science, University of Tokyo, P.O. Takanawa, Tokyo 108, Japan.
Abstract:
Temperature-sensitive mutants of the pat1 gene of Schizosaccharomyces pombe are able to produce poorly viable spores from the haploid state without the requirement for nitrogen starvation if exposed to the restrictive temperature. Three lines of evidence strongly suggest that this gene codes for a factor whose physiological role is inhibition of initiation of meiosis. First, pat1 haploids arrested in G(1) phase undergo apparent premeiotic DNA synthesis at the restrictive temperature. Second, the pat1 gene was found to exert its function at a specified stage of the meiotic pathway by comparison with other meiotic mutants. Third, meiotic recombination and chromosome segregation take place quite normally in pat1 diploids at the restrictive temperature, resulting in the production of highly viable spores. A negative control mechanism for meiosis is proposed.
Insights
The pat1 gene in Schizosaccharomyces pombe inhibits meiosis initiation. Temperature-sensitive pat1 mutants bypass nitrogen starvation, enabling meiotic DNA synthesis and spore formation in haploids.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- The pat1 gene in Schizosaccharomyces pombe plays a crucial role in regulating meiosis.
- Understanding the function of pat1 is key to deciphering the genetic control of meiotic initiation.
Purpose of the Study:
- To investigate the physiological role of the pat1 gene in meiosis.
- To determine if pat1 functions as an inhibitor of meiotic initiation.
Main Methods:
- Utilizing temperature-sensitive mutants of the pat1 gene in Schizosaccharomyces pombe.
- Analyzing meiotic progression, DNA synthesis, recombination, and spore viability under restrictive temperatures.
- Comparing pat1 mutant phenotypes with other known meiotic mutants.
Main Results:
- Temperature-sensitive pat1 mutants initiate meiosis and produce poorly viable spores from the haploid state without nitrogen starvation.
- pat1 haploids in G(1) arrest show premeiotic DNA synthesis at the restrictive temperature.
- Meiotic recombination and chromosome segregation are normal in pat1 diploids at the restrictive temperature, yielding viable spores.
Conclusions:
- The pat1 gene product likely inhibits the initiation of meiosis.
- A negative control mechanism for meiosis involving pat1 is proposed.
- This finding provides insights into the regulation of the meiotic pathway.
Related Concept Videos
02:02Meiosis II
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
01:57Meiosis II
03:09Meiosis I
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
01:49Meiosis I
02:57Meiosis vs. Mitosis
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...