A hidden genetic code Sunday, Jan. 20, 2013 Harvard Gazette
Researchers identify key differences in seemingly synonymous parts of the structure
Excerpt: “Given the universal nature of the genetic code — the system works the same way for all organisms, from single-celled bacteria to human beings — Subramaniam hopes to explore what role, if any, differences in the seemingly synonymous portions of the genetic code may have in other organisms, and whether those differences can be exploited by researchers.”
Open access article: Environmental perturbations lift the degeneracy of the genetic code to regulate protein levels in bacteria
My comment:
A hidden genetic code altered only by nutrients could not lead to beneficial adaptations via mutations, which are typically deleterious. Instead, species diversification in microbes to man is controlled by the metabolism of nutrients to pheromones — not by mutations. Nutrient-dependent pheromone-controlled reproduction is not a function of mutations; it’s a function of life that begets other life and the observed diversity of life that is nutrient dependent and pheromone-controlled.
The epigenetic effects of nutrient chemical stress and social stress alter the microRNA/messenger RNA balance, intracellular signaling, and stochastic gene expression that is responsible for adaptive evolution in species from microbes to man. That’s how chemical ecology is linked to the cellular metabolism of nutrients that chemically control reproduction. As indicated by Subramaniam, the systems biology approach is the same in all organisms.
The receptor-mediated molecular handshake that enables E. coli to metabolize citrate exemplifies how the epigenetic landscape becomes the physical landscape via chromatin remodeling. Nutrient-dependent pheromone-controlled reproduction of E. coli via quorum sensing ensures that the organism does not exhaust its nutrient supply.
In this article, however, nutrient-dependent perturbations are inappropriately placed in the context of mutating codons. Perturbations cause mutations that lead to an evolutionary dead end. Indeed, the researchers note that mRNA cannot solely be responsible for adaptive evolution of de novo gene expression and protein synthesis. There must be top-down control of nutrient-dependent perturbations, and that control comes from the metabolism of nutrients to pheromones.
Perturbations in the balance enable stochastic gene expression that is controlled by the epigenetic effects of the metabolism of nutrients to species specific pheromones. The pheromones control nutrient-dependent reproduction via alterations in the microRNA / mRNA balance.
