Related Experiment Video

Updated: Apr 1, 2026

Identification of Host Pathways Targeted by Bacterial Effector Proteins using Yeast Toxicity and Suppressor Screens
07:40

Identification of Host Pathways Targeted by Bacterial Effector Proteins using Yeast Toxicity and Suppressor Screens

Published on: October 25, 2019

6.5K

Clonal lethality caused by the yeast plasmid 2 mu DNA

C Holm

    Cell
    |June 1, 1982
    PubMed

    Insights

    The NIB gene mutation in Saccharomyces cerevisiae causes abnormal cell growth and colony morphology due to increased 2-micron DNA copy number. This defect in DNA replication regulation leads to larger cells and mortal clones.

    Area of Science:

    • Yeast genetics
    • Molecular biology
    • Cellular regulation

    Background:

    • Saccharomyces cerevisiae strains with the nib allele and 2-micron DNA exhibit a
    • nibbled
    • colony morphology.
    • This phenotype is linked to a subpopulation of abnormally large cells.

    Purpose of the Study:

    • Investigate the cause of the nibbled colony phenotype.
    • Determine the relationship between cell size, 2-micron DNA copy number, and the NIB allele.
    • Elucidate the function of the NIB gene.

    Main Methods:

    • Phenotypic analysis of yeast colonies.
    • Cell size determination.
    • Quantification of 2-micron DNA copy number.

    Main Results:

    • The nibbled phenotype correlates with large cells resulting from DNA replication or nuclear division defects.
    • Large nib cells have double the 2-micron DNA copy number compared to small cells.
    • Elevated 2-micron DNA copy number causes increased cell size.

    Conclusions:

    • The NIB gene product normally represses 2-micron DNA amplification.
    • The nib allele is partially defective, leading to uncontrolled 2-micron DNA copy number increase and the nibbled phenotype.

    More Related Videos

    Targeted in Situ Mutagenesis of Histone Genes in Budding Yeast08:48

    Targeted in Situ Mutagenesis of Histone Genes in Budding Yeast

    Published on: January 26, 2017

    16.6K
    Genetic Engineering of an Unconventional Yeast for Renewable Biofuel and Biochemical Production10:10

    Genetic Engineering of an Unconventional Yeast for Renewable Biofuel and Biochemical Production

    Published on: September 20, 2016

    15.4K

    Related Concept Videos

    Plasmids01:28

    Plasmids

    Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
    3.9K
    Yeast Signaling01:28

    Yeast Signaling

    Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
    18.5K
    Conservative Site-specific Recombination and Phase Variation02:53

    Conservative Site-specific Recombination and Phase Variation

    Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
    The recognition sites for Cre recombinase called LoxP...
    7.4K