Local modulation of chemoattractant concentrations by single cells: dissection using a bulk-surface computational model

This is part of the Theme issue ‘Coupling geometric partial differential equations with physics for cell morphology, motility and pattern formation’

Excerpt: “The computed ligand concentration and receptor occupancy on the evolving cell membrane are shown in figure 5.”

Conclusion: “…the detailed information gained through simulations of single cells or the interaction of a few cells could be used to better inform agent-based approaches and the use of macroscopic models using partial differential equations to evolve cell density fields [39,40]. Currently, such models usually presume that individual cells perceive the concentration of chemoattractant in the bulk medium, in a large-scale gradient. The work we have described shows both presumptions are inaccurate. Taking local breakdown into account, cells may perceive only a small fraction of the bulk attractant concentration, which depending on the level of receptor saturation may make the attractant cause a greater or smaller change in the signal perceived by the cell. Similarly, breakdown may reshape the local steepness of gradients as well as their amplitude. The effect of local attractant breakdown should therefore be considered even in larger-scale models.”

My comment: They link physics and chemistry to the molecular mechanisms of biologically-based cause and effect. Recognition of the pattern formation can be linked from the energy-dependent de novo creation of G protein-coupled receptors to chemotaxis, phototaxis, and the physiology of reproduction via codon usage and RNA-mediated protein folding chemistry in all living genera. They need only recognize the links from the innate immune system to supercoiled DNA, which protects all organized genomes from virus-driven entropy.

In larger scale models, top-down causation links the sun’s anti-entropic virucidal energy to biophysically constrained cell type differentiation via nutrient energy-dependent RNA-mediated amino acid substitutions that differentiate all cell types in all individuals of all living genera. That’s why there has never been a need for serious scientists to base their claims on the pseudoscientific nonsense touted by neo-Darwinian theorists. The differences in scale must link energy-dependent changes from angstroms to ecosystems, but even this report links energy as information to the automagical evolution of the cell membrane, which must be linked to receptor mediated behaviors by serious scientists. Clearly, theorists have an advantage over serious scientists. There is no need for a theorist to explain how the cell membrane “evolved” in the context of energy-dependent changes in hydrogen-atom transfer in DNA base pairs in solution that link the sun’s biological energy to all biodiversity. Only serious scientists are required to link energy-dependent metabolic networks to genetic networks in models of biologically-based cause and effect.

For example: This is the large scale model. Intrinsic limits to gene regulation by global crosstalk

See also: The large-scale model links the representations in Experience-Dependent Plasticity Drives Individual Differences in Pheromone-Sensing Neurons from energy-dependent changes in angstroms to ecosystems via a mammalian model. See their highlights:

•Individual differences in cell types are not random
•Sex differences in pheromone-sensing neurons are controlled by experience
•Changes in specific cell types are governed via “use it and lose it” plasticity
•Targeting plasticity to specific cell types changes animal behavior

However, they also claim: Altogether, the mechanism of plasticity remains unknown and an important topic for future studies.

The article was reported as: Long-term exposure to female scents changes courtship behavior in male mice, which linked nutrient energy-dependent changes to the pheromone-controlled physiology of reproduction in species from microbes to humans.  The molecular mechanisms of biologically based cause and effect were detailed in the context of plasticity in: From Fertilization to Adult Sexual Behavior

See also: Olfactory organ of Octopus vulgaris: morphology, plasticity, turnover and sensory characterization

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