Jumping Genes: The Movers in Our DNA

vidyarthee2021
Jun 23
2 min read

A recent study has highlighted the behavior of LINE-1, a type of jumping gene, which binds to cellular DNA during short windows of cell division. This discovery offers new insights into genome regulation and mutations.

What are Jumping Genes?

Also called Transposable Elements (TEs), they are DNA sequences that can move from one part of the genome to another.
Discovered by Barbara McClintock (Nobel Prize, 1983) in maize.
Two primary types:
1. Retrotransposons (copy and paste) – e.g., LINE-1
2. DNA transposons (cut and paste)

How Do They Work?

LINE-1 replicates by making an RNA copy, then using reverse transcriptase to insert itself elsewhere.
They can:
- Disrupt gene function (by inserting into coding regions)
- Cause mutations
- Contribute to genetic diversity or genetic disorders
In humans, over 50% of our genome consists of transposable elements.

Why It Matters

Their movement can affect gene expression, influence evolution, or lead to diseases like cancer.
Studying LINE-1 gives insights into how genome integrity is maintained or disrupted during cell division.

UPSC Relevance

GS Paper 3: Science & Tech – Biotechnology, Genetics, Genomic Engineering
Important for understanding genomic structure, mutations, and biological inheritance

UPSC Prelims Question

Q. With reference to Transposable Elements (Jumping Genes), consider the following statements:

They are capable of moving within the genome.
LINE-1 is a type of DNA transposon that uses cut-and-paste mechanism.
Jumping genes constitute over half of the human genome.

Which of the statements given above is/are correct?

A. 1 and 3 only

B. 2 and 3 only

C. 1 and 2 only

D. 1, 2 and 3

✅ Answer: A. 1 and 3 only

Explanation:

Statement 1 is correct: TEs move within the genome.
Statement 2 is incorrect: LINE-1 is a retrotransposon using copy-and-paste, not cut-and-paste.
Statement 3 is correct: They make up more than 50% of the human genome.