WordGarden.ioexon
C2Pronunciation
UK
- /ɛɡzˈɒn/
US
- /ˌɛkˈsɔn/
Meanings
Noun
a segment of a gene or transcript retained in mature RNA after splicing
Beyond the definition
Imagine your genes are like long recipes for making everything that makes you you. But these recipes are not written in one smooth stream. They are broken into pieces. Exons are the parts that stay in the RNA after editing. They often carry the instructions for building proteins, the workhorses of our cells, though some parts help in other ways instead of directly coding for protein.
During gene expression, these parts are stitched together while the introns are removed. That is why they matter so much: they shape the final message the cell uses. Scientists study them to understand how genes work and how changes in DNA can lead to disease.
In the world of genetics, DNA is not a simple, unbroken code. It is more like a long manuscript with key passages mixed in among sections that will later be cut out. Exons are the segments of a gene that remain in the final RNA after splicing. Many of them contain instructions for building proteins, while others are kept in the RNA but do not directly code for protein.
Think of a gene as a story. The exons are the parts that make it into the final printed version. Between them are introns, sections that are copied at first but then removed before the message is used.
During RNA splicing, the introns are removed, and the exons are joined together. If the gene makes a protein, the finished messenger RNA (mRNA) is then read as a template for building that protein. Because of this, a change in an exon can alter the final message and sometimes change how a protein is made or works.
Scientists study exons to understand gene activity, find disease-related changes, and improve diagnosis. One important tool is exome sequencing, which looks at the exon regions across the genome because many harmful variants are found there. Understanding exons helps researchers read the useful parts of genetic information more clearly.
Examples
- 1
Gene mutation
The mutation was found in exon 3 of the gene.
- 2
RNA processing
During RNA processing, the cell joins the exons together after removing the introns.
- 3
DNA sample
The lab found that one exon was missing from the patient's DNA sample.
See also
Forms and spellings
1 form open this card.
Main spelling
- exonnoun