2018/03/23

The DNA gene is dead

More reasons why DNA doesn't determine traits

http://physics.scsu.edu/~dscott/gen/Genome2.0.htm

Summary:
  • Now it's clear that a single length of DNA can be transcribed in multiple ways to produce many different RNAs, some coding for proteins and others constituting regulatory RNAs.
  • By starting and stopping in different places, the transcription machinery can generate a regulatory RNA from a length of DNA that overlaps a protein-coding gene.
  • The same sequences are being used for multiple functions. That introduces complications into the evolution of the genome, which had until recently been assumed to act through single DNA mutations affecting single genes.
  • Moreover, the code for another regulatory RNA might run in the opposite direction on the facing strand of DNA.
  • More fundamentally, it muddies scientists' conception of just what constitutes a gene. In the established definition, a gene is a discrete region of DNA that produces a single, identifiable protein in a cell. But the functioning of a protein often depends on a host of RNAs that control its activity. If a stretch of DNA known to be a protein-coding gene also produces regulatory RNAs essential for several other genes, is it somehow a part of all those other genes as well?
  • Multiple and overlapping genes can occupy a single strip of DNA that also produces several functional RNAs that don't encode proteins.
  • To make things even messier, the genetic code for a protein can be scattered far and wide around the genome. The ENCODE project revealed that about 90 percent of protein-coding genes possessed previously unknown coding fragments that were located far from the main gene, sometimes on other chromosomes.
  • Offering a radical new conception of the genome, Gingeras proposes shifting the focus away from protein-coding genes. Instead, he suggests that the fundamental units of the genome could be defined as functional RNA transcripts.

My comment: The cell uses the DNA for building different RNA-products. It's likely that the cell is able to choose appropriate strands of the DNA and build essential RNA transcripts for different purposes. Overlapping, embedded  and opposite-directional DNA strands tell us about very complex, designed mechanisms the cell uses for building RNA-products. After realising this complexity and the way the DNA is used, we should also understand that

- The DNA is not your destiny
- Genetic determinism is a serious heresy
- The DNA doesn't dictate traits of organisms
- The DNA has no control over cellular processes
- Mutations never lead to evolution but gradual degradation of the genome
- It's a waste of money to buy a DNA test. Those tests tell you about genetic markers left by epigenetic mechanisms and genetic errors. (http://www.els.net/WileyCDA/ElsArticle/refId-a0006159.html)