Context:
Studies suggest that epigenome editing offers a gentler approach to performing gene editing.
Epigenome Editing for Gene Regulation
- Epigenome editing: Genetic engineering that adjusts gene transcription by modifying the epigenome, targeting the root of dysregulation while keeping the primary DNA sequence intact.
- Epigenome: All chemical compounds and modifications (e.g., methyl groups, histone modifications) that regulate gene expression without altering the DNA sequence.
- Safer alternative: Unlike traditional gene editing, which involves cutting DNA, epigenome editing offers precise, reversible control over gene expression.
- Role of Epigenetic Processes in Gene Regulation:
- Regulates gene expression predominantly at the level of transcription.
- Transcription: Process of copying a gene’s DNA sequence into an RNA molecule.
Epigenetic Markers
- DNA Methylation: Adds a methyl group to DNA, silencing genes by preventing transcription factors from binding.
- Histone Modification: Alters histone proteins (DNA-wrapping proteins) through chemical changes, influencing gene expression.
- RNA-Mediated Processes: Uses non-coding RNAs to regulate genes effectively.
What is Epigenetics?
- Epigenetics: Study of how cells control gene activity without altering the DNA sequence.
- Epigenetic changes: Modifications to DNA that regulate gene activation (on/off) without altering DNA sequence.
- Modifications are attached to DNA but do not change its building blocks.
- Influence protein production by controlling gene activation, ensuring cells produce only necessary proteins (e.g., bone growth proteins are absent in muscle cells).
- Patterns of epigenetic modifications vary among individuals, tissues within an individual, and cells within a tissue.
Key Applications of Epigenome Editing
- Treatment of Complex Diseases: Cancer, neurological disorders, and metabolic syndromes: Addresses conditions caused by multiple genetic factors.
- Regenerative Medicine: Enhances stem cell therapies by controlling cell differentiation and promoting tissue repair.
- Immune System Engineering: Optimizes immune cell functions for advanced cancer immunotherapies.
- Safe and Reversible Gene Therapies: Reduces risks of permanent genetic modifications, providing precise and controlled treatments.
Methods to Achieve Epigenome Editing:
- CRISPR-Based Epigenetic Editing
- Utilizes modified CRISPR-Cas systems to recruit epigenetic modifiers.
- Alters gene expression without cutting the DNA sequence.
- Zinc Finger Proteins (ZFPs)
- Engineered proteins designed to bind specific DNA sequences.
- Recruit enzymes to modify epigenetic markers, enabling targeted gene activation or repression.
- Transcription Activator-Like Effectors (TALEs)
- Customizable DNA-binding proteins similar to ZFPs.
- Influence gene expression by modifying epigenetic markers.
Source: The Economist
Previous Year Question
‘Aerial metagenomics’ best refers to which one of the following situations?
[UPSC Civil Services Exam – 2023 Prelims]
(a) Collecting DNA samples from air in a habitat at one go
(b) Understanding the genetic makeup of avian species of a habitat
(c) Using air-bome devices to collect blood samples from moving animals
(d) Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies
Answer: (a)
