The Mystery of Gene Creation

Sub : Sci

Sec: Biotech

Why in News

Recent studies published in Molecular Biology and Evolution by the University of Nevada, Reno, and Genome Biology and Evolution by the Max Planck Institute for Evolutionary Biology have provided groundbreaking insights into the process of gene creation, addressing longstanding questions in evolutionary biology.

Key Concepts:

Genes are specific segments of DNA that influence an organism’s characteristics. They play a critical role in defining individuality.
Human Genome: Composed of 2 billion base pairs.
- Contains 20,000 protein-coding genes and another 20,000 genes involved in RNA creation.
- Includes promoters and enhancers, which regulate gene expression.
Chromosomal Makeup: Humans have 24 chromosomes: 22 autosomes and two sex chromosomes (X and Y). Biological females have two X chromosomes; males have one X and one Y.
DNA Composition: DNA consists of two strands held together by base pairs. Two key compounds involved are cytosine and thymine.

How New Genes Are Formed:

New genes are primarily created through a process known as gene duplication, first proposed by Susumu Ohno in 1970.
Duplication: When a gene is copied, the original continues its function, while the duplicate is free to undergo mutations without affecting the organism’s current functionality.
Acquisition of New Functions: Over time, mutations in the duplicate gene may lead to novel functions, providing the organism with evolutionary advantages.
Challenges in Duplication: Duplicate genes can cause harmful protein overproduction. To address this, cells regulate these genes to prevent adverse effects.
Research Insights: Studies revealed that methylation of duplicate genes helps suppress their activity initially, preventing excessive protein production.
This suppression allows the duplicates to survive long enough to mutate and evolve into functional genes.

What is Methylation?

Methylation is a biochemical process where a methyl group (CH₃) is added to DNA molecules, often at cytosine bases.
Role in Gene Regulation: Methylation typically suppresses gene activity by preventing transcription, controlling which genes are active in a cell.
In duplicated genes, methylation prevents overexpression, allowing these genes to remain functional without causing harm.
Impact on Evolution: Methylation increases mutation rates, enabling duplicate genes to develop new roles over time.

What is Random DNA?

Random DNA refers to sequences in the genome that do not initially code for specific proteins or functions.
Random DNA can occasionally influence biological processes, behaving like incipient genes (early-stage genes).
These sequences may eventually evolve into functional genes through natural selection and mutation, contributing to genetic diversity.