Chromatin Topology: the New (and Latest) Functional Complexity
|July 23, 2018||Posted by PaV under Intelligent Design|
There’s a paper out in Nature Genetics discussing “chromatin topology.” Here’s the abstract:
A long-standing question in gene regulation is how remote enhancers communicate with their target promoters, and specifically how chromatin topology dynamically relates to gene activation. Here, we combine genome editing and multi-color live imaging to simultaneously visualize physical enhancer–promoter interaction and transcription at the single-cell level in Drosophila embryos. By examining transcriptional activation of a reporter by the endogenous even-skipped enhancers, which are located 150 kb away, we identify three distinct topological conformation states and measure their transition kinetics. We show that sustained proximity of the enhancer to its target is required for activation. Transcription in turn affects the three-dimensional topology as it enhances the temporal stability of the proximal conformation and is associated with further spatial compaction. Furthermore, the facilitated long-range activation results in transcriptional competition at the locus, causing corresponding developmental defects. Our approach offers quantitative insight into the spatial and temporal determinants of long-range gene regulation and their implications for cellular fates.
This is rather stunning stuff since what they are essentially saying is that the protein wrapping of DNA, the chromatin, is somehow functionally arranged, and that two distant sites on DNA (located 150,000 bases away from each other) NEED to come into contact for enhanced transcriptional activity. And, in the italicized section, they’re saying this comes about because the ‘needed’ conformation is somehow ‘stabilized,’ which means that the overall energy configuration of the local DNA molecule is lowered when put into this ‘conformation.’ (Oh how biochemists would love to be able to do such things!)
This only adds to the complexity of organisms to function properly and leaves in shambles the thought that all of these new layers of complexity came about by some “random” process.
I could post articles like this every day. I don’t because “News” does a good job of it, and over at Evolution and News, serious treatment of the more consequential articles routinely appear.
I cannot understand how any rational human being, aware of all this level of complexity, could possibly maintain a Darwinist, neo-Darwinist, or any other putative evolutionary (random) mechanism explains such orderliness and machine-like functioning.
We’re a long ways from thinking that ovum are just a bunch of goo. And yet . . . .
A related news item: Here.