Controled Stem Cell Expansion
Serine … is one of the proteinogenic amino acids. [It]… is classified as a polar amino acid.
My comment: Serine synthesis in the body is linked to glycine, which also may be naturally produced when UV light illuminates simple ices (e.g., combinations of water, methanol, hydrogen cyanide, and ammonia). That suggested to some people that glycine and other amino acids may be easily produced in cold regions of space, and the suggestion, like virtually all suggestions, seems to be believable to theorists. For contrast, Sutherland’s group linked UV light to the creation of glycine on Earth.
Their research was reported as: Researchers may have solved origin-of-life conundrum
…a pair of simple compounds, which would have been abundant on early Earth, can give rise to a network of simple reactions that produce the three major classes of biomolecules—nucleic acids, amino acids, and lipids—needed for the earliest form of life to get its start.
My comment: That claim may link the UV light-induced de novo creation of glycine on Earth to the RNA-mediated cell type differentiation of all vertebrates. Claims about RNA-mediated cell type differentiation have been made for more than 30 years, and the molecular mechanisms that link cell type differentiation in all species have been detailed. See: RNA mediated
See for comparison: Atypical PKC-iota Controls Stem Cell Expansion via Regulation of the Notch Pathway
These studies, together with data presented here, provide genetic evidence that evolutionarily conserved polarity pathways may play a central role in NOTCH1 activation and stem cell self-renewal in mammals. Further genetic studies using Cre transgenes that are specific for progenitors in the neural plate, primitive erythrocytes, cardiomyocytes, and other progenitors to ablate aPKC function will be needed to determine how generally this mechanism is used in diverse tissues.
…a complete picture for the requirement of aPKCs at different stages of mammalian development has not yet emerged.
…the Notch pathway produces a protein that signals to stem cells to make more stem cells. In the presence of Prkci, the Notch pathway remains silent, and stem cells differentiate into specific cell types.
Arguably, further studies of controlled stem cell expansion will eventually link everything currently known From Fertilization to Adult Sexual Behavior in all mammals via what is currently known about nutrient-dependent RNA-mediated cell type differentiation in all vertebrates.
For example, substitution of achiral glycine in the GnRH decapeptide links food odors and pheromones from atoms to ecosystems via the physiology of reproduction. Predictably, the complete picture that will emerge in mammals will link conserved polarity pathways to the stability of organized genomes in all vertebrates outside the context of theoretical physics and neo-Darwinian theories about mutations and evolution.
Indeed, it seems likely theorists will learn that all RNA-mediated cell type differentiation in all vertebrates is nutrient-dependent and that Feedback loops link odor and pheromone signaling with reproduction, from microbes to humans, since serious scientists have known that for more than a decade.
As we wait for the complete picture to be seen by those who continue to frame their experimental evidence of biologically-based cause and effect in the context of ridiculous theories about evolutionarily conserved polarity pathways, we should remember that many theorists will continue to believe whatever they are taught to believe.
Most of them may never learn anything about how nutrient-dependent RNA-mediated cell type differentiation occurs, which means they may never link species-specific pheromones to morphological and behavioral phenotypes in species from microbes to humans. Indeed, most theorists will never become serious scientists who frame their experimental evidence in the context of biologically-based facts that others have established.