Related Experiment Video
Updated: Aug 3, 2026
07:13
Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry
Published on: August 16, 2016
Summary
Human organ senescence begins around age 20, progressing linearly. DNA methylation loss drives mutations, impacting lifespan and potentially causing hereditary diseases.
Area of Science:
- Gerontology
- Molecular Biology
- Genetics
Context:
- Human organ senescence commences early, around age 20 +/- 10 years.
- Aging exhibits a largely linear progression in functional parameters.
- A proposed aging model links cellular destruction and genomic mutation accumulation to functional decline.
Purpose:
- To investigate the role of DNA methylation in cellular aging and lifespan.
- To analyze the relationship between DNA methylation changes and mutation accumulation.
- To evaluate DNA methylation as a potential biomarker for aging.
Summary:
- Enzymatic DNA methylation generates 5-methylcytosine (5mC) to Thymine (T) transitions during cell division.
- Age-related 5mC loss correlates with the Hayflick limit and maximal lifespan across species.
- DNA hypomethylation rates align with cellular aging rates in vitro and in vivo.
Impact:
- 5mC to T transitions account for over half of vertebrate point mutations, disproportionately affecting methylated sites.
- These mutations contribute significantly to mutagenesis and hereditary human diseases.
- DNA methylation serves as a biomarker for aging and a mechanism for programmed mutation accumulation, with reversed function in immortal cells.
Related Concept Videos
02:31Replication in Eukaryotes
Overview
01:46Epigenetic Regulation
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
03:17Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
02:25Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
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...
01:29Replication 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.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...