What is the function of spliceosomes, introns and exons?
Introns, derived from the term “intragenic regions”, are non-coding sections of DNA. Once a DNA sequence has been transcribed as a hnRNA strand, the introns will be spliced out. The resulting mRNA sequence will then be translated into a protein. A spliceosome is a complex of specialized RNA and protein subunits that removes introns from a transcribed hnRNA (often called pre-mRNA) segment. This process is generally referred to as splicing. An exon is any region of DNA within a gene that is transcribed to the final messenger RNA (mRNA) molecule, rather than being spliced out from the transcribed RNA molecule. Function In many genes, each exon contains part of the open reading frame (ORF) that codes for a specific portion of the complete protein. However, the term exon is often misused to refer only to coding sequences for the final protein. This is incorrect, since many noncoding exons are known in human genes (Zhang 1998)…………………
