““Introns are not the exception in human genes; they are the rule. Human introns are often enormous-spanning several hundreds of thousands of bases of DNA. And genes themselves are separated from each other by long stretches of intervening DNA, called intergenic DNA. Intergenic DNA and introns-spaces between genes and stuffers within genes-are though to have sequences that allow genes to be regulated in context. To return to our analogy; these regions might be described as long ellipses scattered with occasional punctuation marks. The human genome can thus be visualized as: This......is............the......(...)...s...truc...ture......of......your......gen...om...e; The words represent genes. The long ellipses between the words represent the stretches of intergenic DNA. The shorter ellipses within the words (gen...ome...e) are introns. The parentheses and semicolons-punctuation marks-are regions of DNA that regulate genes.””
