Magic embryology: how to grow a limb (Introduction)

by David Turell , Monday, February 05, 2024, 18:31 (82 days ago) @ David Turell

A method is found:

https://phys.org/news/2024-02-simple-recipe-limb.html

"The team found that a combination of just three proteins—Prdm16, Zbtb16, and Lin28a—is necessary and sufficient to turn certain non-limb-forming stem cells into limb-forming ones. A fourth protein, Lin41, speeds the process along.

"Part of a family called gene transcription factors, these proteins activate a handful of genes inside certain cells in embryonic tissue known as mesenchyme, the researchers revealed. This change in gene activity is what transforms the cells into limb progenitor cells, the team showed.

"Limb progenitor cells then bud out where a limb will form and provide a framework for the future arm, leg, wing, or fin.

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"It also remains to be discovered which other ingredients need to be added for limb progenitor cells to mature into the limb's connective tissues, such as tendons, ligaments, and the middle layer of skin.

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"'We tested a lot of conditions to see what the cells like and what they don't like. We found they are particularly finicky about stiffness," said Lee. "The only limitation we've found so far is that the cells grow so well that they fill up the containers we use, which is a good problem to have."

"Developmental and evolutionary biologists and regenerative medicine scientists are now better positioned to answer questions such as:

"The roles the three gene transcription factors play in other organ systems and organisms.

"What factors contribute to later limb development, such as fingers and toes.

"What distinguishes fore- and hind limb development.

"How these insights can inform efforts to regrow different organs to treat injury or disease.
"It's important to understand the basic properties of cells that have a therapeutic value," said Lee. "Culturing and maintaining limb progenitor cells and directing them to more specific lineages is fundamentally important for the long-term goal of replenishing cells in the clinic."

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"'Understanding and harnessing mammalian limb progenitors is a first step toward considering mammals as models for regenerating amputated limbs, as an alternative to the amphibians and other limb-regenerating critters being studied today," said Tabin."

Comment: humans playing God, recoding DNA successfully.