Transcription of DNA to Messenger RNA
The process by which non-coding sequences of base pairs (introns) are subtracted from the coding sequences (exons) of a gene in order to transcribe messenger RNA (mRNA.)
In many genes, the DNA sequence that codes for proteins (exons) may be interrupted by stretches of non-coding DNA, called "introns." In the cell nucleus, the DNA that includes all the exons and introns of the gene is first transcribed into a complementary RNA copy called "nuclear RNA," or nRNA. In a second step, introns are removed from nRNA by a process called RNA splicing. The edited sequence is called "messenger RNA," or mRNA.
The mRNA is able to leave the nucleus for the cytoplasm, where it encounters cellular bodies called ribosomes. The mRNA, which carries the gene's instructions, dictates the production of proteins by the ribosomes.