Related Experiment Video
Updated: Jun 27, 2026
12:08
Telomere Length and Telomerase Activity; A Yin and Yang of Cell Senescence
Published on: May 22, 2013
Lessons From Yeast: Mechanisms of Telomere Length Regulation.
Rini Mayangsari1, Carol W Greider1
1Department of Molecular Cell and Developmental Biology, The RNA Center, and The Genomics Institute, University of California, Santa Cruz, California, USA;
Annual Review of Genetics
|June 25, 2026
Summary
Telomeres protect chromosome ends but shorten with cell division. Telomerase balances this, but dysregulation causes disease or cancer. Understanding telomere length regulation is key for human health.
Area of Science:
- Genetics
- Molecular Biology
- Cell Biology
Background:
- Telomeres are protective DNA sequences at chromosome ends.
- Telomere shortening occurs due to incomplete DNA replication.
- Telomerase counteracts shortening, maintaining telomere length homeostasis.
Purpose of the Study:
- To elucidate the regulatory pathways governing telomere length.
- To understand the fundamental mechanisms of telomere maintenance.
- To provide insights for targeting telomere length in human diseases.
Main Methods:
- Focus on fundamental mechanisms established in yeast (Saccharomyces cerevisiae).
- Review of established pathways regulating telomere length.
- Analysis of the balance between telomere shortening and lengthening.
Main Results:
- Telomere length is tightly regulated through a balance of shortening and lengthening.
- Perturbation of this balance leads to cellular senescence or death.
- Short telomeres are linked to age-related diseases, while long telomeres can promote cancer.
Conclusions:
- A comprehensive understanding of telomere length regulation is crucial for addressing human diseases.
- Yeast models provide fundamental insights into conserved telomere maintenance mechanisms.
- Further research into these pathways can inform therapeutic strategies.
Related Concept Videos
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
01:29Replication in Eukaryotes
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
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02:31Replication in Eukaryotes
Overview
02:15Replicative Cell Senescence
Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds the telomeric...
02:15Replicative Cell Senescence
Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds the telomeric...