In gene expression, what is the primary role of introns?

In gene expression, introns primarily serve the role of being removed from the RNA transcript during the process of splicing. Introns are non-coding sections of a gene that are transcribed into precursor mRNA but are not translated into proteins. Once the mRNA is synthesized, the introns are excised, and the remaining coding sequences, known as exons, are joined together to form a mature mRNA that can be translated into a protein.

This splicing process is crucial for the proper expression of genes because it enables the production of various protein isoforms (alternative splicing), thereby increasing the diversity of proteins that can be synthesized from a single gene. The removal of introns ensures that only the necessary coding information is included in the final mRNA, which is essential for accurate translation and functional protein production.