[2009/07/20] Genomic Junk” Is Cell’s Air-Traffic Control
“Genomic Junk” Is Cell’s Air-Traffic Control 07/20/2009 July 20, 2009 — Linc-RNAs (large intervening non-coding RNAs) have been promoted from junk molecules to air traffic controllers. A mystery about these transcripts of DNA that are not translated into proteins is being explained. Science Daily reported on work at Beth Israel Deaconess Medical Center (BIDMC) and the Broad Institute that found these RNA molecules perform a vital task. “linc-RNAs, once dismissed as ‘genomic junk’ – have a global role in genome regulation, ferrying proteins to assist their regulation at specific regions of the genome.” Results were published in the July 14 issue of the Proceedings of the National Academy of Sciences.
“I like to think of them as genetic air traffic controllers,” explains co-senior author John Rinn, PhD, a Harvard Medical School Assistant Professor of Pathology at BIDMC and Associate Member of the Broad Institute. “It has long been a mystery as to how widely expressed proteins shape the fate of cells. How does the same protein know to regulate one genomic location in a brain cell and regulate a different genomic region in a liver cell? Our study suggests that in the same way that air traffic controllers organize planes in the air, lincRNAs may be organizing key chromatin complexes in the cell.”
It has been known for some time that small RNA transcripts are involved in gene regulation, but link-RNAs are often thousands of base pairs long. The article said, “they seemed more like genomic oddities than key players” till now. “With these latest findings, which also uncovered an additional 1,500 lincRNAs, it’s clear these RNA molecules are no mere messengers – they have demonstrated that they can and do play a leading role.” Speaking of differences in brain cells and liver cells, another article on Science Daily smashed a paradigm: “DNA Not The Same In Every Cell Of Body: Major Genetic Differences Between Blood And Tissue Cells Revealed.” A discovery by Montreal scientists “calls into question one of the most basic assumptions of human genetics: that when it comes to DNA, every cell in the body is essentially identical to every other cell.” It appears that biologists and geneticists are finding new complexities in the way genes are distributed and regulated in body cells. The discoveries may lead to better understanding of the factors that make cells in various tissues look and behave differently.
Neither of these articles needed evolutionary theory. When the trend in scientific discovery is to uncover more and more complexity, regulation, and function such that air traffic control is the analogy that comes to mind, intelligent design “leaps up as the most likely explanation,” as Jonathan Wells put it. Pilot Charlie, preferring unguided processes, appears headed for a nose dive.