A dozen or so years ago I wrote a paper on flower patterning using Turing's tessellation model. I demonstrated based upon theory and experiment the validity of the model and have used it in Hemerocallis hybridizing.
Now along come some scientists who announce that this can apply to animal spots. Science notes:
In 1952, computing pioneer Alan Turing suggested molecules that inhibit and activate each other could create periodic patterns in nature if they diffused through tissue at different rates. Thirty years later, other scientists applied his theory to develop a hypothesis about how spots, stripes, and other color patterns form during development. In this scheme, activator molecules color a cell but also trigger the production of inhibitors, which diffuse faster than the activators and can shut off pigment production. Last year, that idea was proved correct in plants called monkeyflowers: Researchers showed that dark, activated speckles on the petals become ringed with unpigmented tissue as inhibitors spread (Science, 30 August 2019, p. 854). And researchers had shown molecules following the Turing pattern help trigger the development of hair follicles in mice. But how coat color develops in mammals remained largely mysterious because mice and other easy-to-study lab animals lack spots or stripes. So Barsh's team turned to domestic cats to track the identity of molecular activators and inhibitors of coat color. A decade ago, they tracked down a gene, Tabby, that, when mutated, gives tabby cats black blotches instead of their usual dark stripes. HudsonAlpha geneticist Christopher Kaelin found that same mutation in king cheetahs whose spots were unusually big and blotchy, suggesting the same genes color both wild and domestic cats.
Sorry folks but we were a bit ahead of you. I recall having a debate with some epigeneticists regarding methylation versus the Turing model. Lost that one since they had no idea of the model nor of the complex pathways. Nice to see it resurrected again.
Imagine what could have happened if Turing had lived!
Posts
