Junk DNA

Source-This post on Junk DNA has been created based on the article “New class of cancer mutations discovered in so-called ‘junk’ DNA” published in “Medical Press” on 3 July 2024.

Why in the news?

Researchers using artificial intelligence have discovered potential cancer drivers hidden within so-called ‘junk’ regions of DNA.

About Junk DNA

1. In genetics, junk DNA refers to regions of DNA that are noncoding. While DNA contains instructions (coding) for creating proteins in cells, not all genetic sequences within a DNA molecule code for proteins.

2.  DNA can be a coding DNA which uses instructions to create proteins and noncoding DNA which are sequences that do not code for proteins.

3. Types of Noncoding DNA: Some noncoding DNA is used to produce non-coding RNA components, such as Transfer RNA (tRNA), regulatory RNA and ribosomal RNA (rRNA).

4. Junk DNA: Other regions of noncoding DNA are not transcribed into proteins or used to produce RNA molecules, and their function is unknown. These are referred to as junk regions of DNA.

5. Proportion of Coding vs. Noncoding DNA: The proportion of coding versus noncoding DNA varies significantly between species:

i) Humans have about 98% of the DNA is noncoding.

ii) Bacteria have only about 2% of the genetic material is noncoding.

6. Functional Activity in Junk DNA: Despite being labeled as junk, researchers have found evidence suggesting that junk DNA may have some functional activity. For instance, fragments of what were originally non-functional DNA might have acquired a function through a process called exaptation.

Note: Exaptation refers to the acquisition of a function through means other than natural selection, indicating that these noncoding regions might have roles that are not yet fully understood.

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