Certain cephalopods such as squid, octopuses, and cuttlefish have the ability to camouflage themselves by making themselves invisible or changing color. Scientists would like to know more about the exact mechanisms underlying this unique ability, but they can’t grow squid skin cells in the lab. They’ve found a solution: to replicate the properties of squid skin cells in mammalian (human) cells in the lab. bottom.
“Generally, there are two ways to achieve transparency,” said Aron Gorodetsky of the University of California, Irvine, who has been fascinated by squid camouflage for the past decade or so, in a media briefing at the ACS conference. . “One way is to reduce the amount of light that is absorbed, usually pigment-based coloring. Another way is to change the way light scatters, usually by changing the difference in refractive index. The latter is the focus of his lab’s research.
Cuttlefish skin is translucent and has an outer layer of pigmented cells called chromatophores that control the absorption of light. Each chromatophore is attached to muscle fibers that line the surface of the skin, and these fibers are connected to nerve fibers. It’s easy to stimulate these nerves with electrical pulses to make the muscles contract. Also, as the muscle is pulled in different directions, the cells expand along with the pigmented area and change color.
Below the chromatophore is another layer of iridophores. Unlike chromatophores, iridophores are not pigment-based, but are examples of structural colors similar to butterfly wing crystals, except that squid iridophores are dynamic rather than static. It can be tuned to reflect a certain wavelength of light. A 2012 paper suggested that this dynamically tunable structural color of iridophores is related to a neurotransmitter called acetylcholine. The two layers work together to produce the unique optical properties of squid skin.
And they are similar to iridophores, except they have leukophores and scatter the entire spectrum of light to appear white. They usually contain reflectin proteins that aggregate into nanoparticles so that light is scattered instead of being absorbed or directly transmitted. Leucophores are found mainly in squid and octopuses, but there are also females of the genus Squid. Sepiotheutis They have leukophores that can be “tuned” to scatter only certain wavelengths of light. Cells appear more transparent when they let light pass through them with little scattering, whereas cells become opaque and clearer by scattering more light. These are the cells Gorodetsky is interested in.
