intronok
Intronok, or introns, are non-coding segments within genes that are transcribed into precursor messenger RNA but removed from the final mRNA during RNA processing. They separate coding regions, called exons, and are found in most eukaryotic genes. Most introns are removed by the spliceosome, a large RNA-protein complex, through a two-step transesterification process that joins exons together and forms a lariat intermediate.
There are several classes of introns. The majority are spliceosomal introns, which are further divided into
Intron number and length vary widely among organisms and genes. Some genes are intronless, while others contain
Evolutionarily, introns are thought to arise and be lost over time, with frequent intron gain and loss