Early embryology; requires brain input: (Introduction)

by David Turell , Friday, March 16, 2018, 19:23 (2444 days ago) @ David Turell

Shown in tadpole research:

https://www.quantamagazine.org/brainless-embryos-suggest-bioelectricity-guides-growth-2...

"In recent years, by working on tadpoles and other simple creatures, Levin’s laboratory has amassed evidence that the embryo is molded by bioelectrical signals, particularly ones that emanate from the young brain long before it is even a functional organ. Those results, if replicated in other organisms, may change our understanding of the roles of electrical phenomena and the nervous system in development, and perhaps more widely in biology.

“'Levin’s findings will shake some rigid orthodoxy in the field,” said Sui Huang, a molecular biologist at the Institute for Systems Biology. If Levin’s work holds up, Huang continued, “I think many developmental biologists will be stunned to see that the construction of the body plan is not due to local regulation of cells … but is centrally orchestrated by the brain.”

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“'It’s too simplistic to consider the genome as the only source of biological information,” she said. Researchers continue to study morphogens as a source of developmental information in the nervous system, for example. Last November, Levin and Chris Fields, an independent scientist who works in the area where biology, physics and computing overlap, published a paper arguing that cells’ cytoplasm, cytoskeleton and both internal and external membranes also encode important patterning data — and serve as systems of inheritance alongside DNA.

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"Then Levin and his colleagues decided to flip the experiment. Might the brain hold, if not an entire blueprint, then at least some patterning information for the rest of the body, Levin asked — and if so, might the nervous system disseminate this information bioelectrically during the earliest stages of a body’s development? He invited Herrera-Rincon to get her scalpel ready.

"Herrera-Rincon’s brainless Xenopus laevis tadpoles grew, but within just a few days they all developed highly characteristic defects — and not just near the brain, but as far away as the very end of their tails. Their muscle fibers were also shorter and their nervous systems, especially the peripheral nerves, were growing chaotically.

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"Levin’s research demonstrates that the nervous system plays a much more important role in how organisms build themselves than previously thought, said Min Zhao, a biologist at the University of California, Davis, and an expert on the biomedical application and molecular biophysics of electric-field effects in living tissues. Despite earlier experimental and clinical evidence, “this paper is the first one to demonstrate convincingly that this also happens in [the] developing embryo.”

“'The results of Mike’s lab abolish the frontier, by demonstrating that electrical signaling from the central nervous system shapes early development,” said Olivier Soriani of the Institut de Biologie de Valrose CNRS. “The bioelectrical activity can now be considered as a new type of input encoding organ patterning, allowing large range control from the central nervous system.'”

Comment: Embryology has always been an issue for Darwin evolution theory. It is such a complex process, making a new individual in exactly correct form cannot be a process developed by chance.