Related Experiment Video
Updated: Aug 13, 2026
15:09
Flow Cytometry-based Purification of S. cerevisiae Zygotes
Published on: September 21, 2012
Multiple epigenetic events regulate mating-type switching of fission yeast
A J Klar1, A V Ivanova, J Z Dalgaard
1National Cancer Institute-Frederick Cancer Research, Frederick, MD 21702-1201, USA.
Novartis Foundation Symposium
|May 27, 1998
Summary
Epigenetic events at mat1 initiate mating-type switching via DNA strand-specific recombination. An imprinted event at mat2/3 controls gene silencing and prevents interchromosomal recombination, suggesting DNA and chromatin structure are inherited units.
Area of Science:
- Epigenetics
- Molecular Biology
- Genetics
Background:
- Mating-type switching is a crucial process in many organisms.
- Epigenetic mechanisms play a significant role in regulating gene expression and inheritance.
- Understanding the control of recombination and gene silencing is vital for developmental biology.
Purpose of the Study:
- To elucidate the epigenetic events governing mating-type switching.
- To investigate the role of specific loci (mat1 and mat2/3) in recombination and gene silencing.
- To explore the nature of inheritance at the mat2/3 interval.
Main Methods:
- Analysis of epigenetic modifications at the mat1 locus.
- Investigation of DNA strand-specific events during recombination initiation.
- Study of imprinted events at the mat2/3 interval.
- Examination of gene silencing and interchromosomal recombination regulation.
Main Results:
- Two DNA epigenetic events at mat1, including a strand-specific one, are necessary for initiating recombination.
- A third, imprinted epigenetic event at the mat2/3 interval regulates silencing and switching directionality.
- This imprinted event also prevents interchromosomal recombination.
Conclusions:
- Epigenetic regulation is critical for controlling mating-type switching and recombination.
- The mat2/3 interval may be inherited as a unit of DNA and associated chromatin structure.
- Such epigenetic control mechanisms are likely essential for maintaining specific gene expression states during development.
Related Concept Videos
01:28Yeast 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...
01:57Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
02:50Dosage Compensation
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
01:37Epigenetic Regulation
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
X-chromosome...
01:24Methods of Nuclear Reprogramming
Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.