Jakarta –
Animals in this world have various patterns. There are animals that have striped, round, or even abstract motifs on their bodies.
Biologists have previously shown that many animals evolved patterns to camouflage themselves or attract mates. Genes do encode pattern information such as the color of a leopard’s spots, but genetics alone don’t explain where exactly those spots will develop.
In 1952 before biologists discovered the double helix structure of DNA, Alan Turing, the mathematician who invented modern computing, proposed a theory about how animals get their patterns.
Turing hypothesized that as tissues develop, they produce chemicals. These chemical agents diffuse through the tissues in a process similar to adding milk to coffee.
Some agents react with each other, forming spots. While others inhibit the spread and reaction of agents, forming spaces between points. Turing’s theory states that instead of complex genetic processes, this simple reaction-diffusion model is sufficient to explain the basics of animal biological pattern formation.
What Does the Research Say?
A study of patterns on animal bodies has been uploaded by a number of researchers through the journal Science Advances.
“Of course the Turing mechanism can produce patterns, but diffusion does not produce sharp patterns,” said the study’s corresponding author, Ankur Gupta, as quoted on the University of Colorado website.
For example, when milk diffuses in coffee, it flows in all directions in unclear lines, he said.
“Many biological questions are essentially the same question: How do organisms develop complex patterns and shapes when everything starts from spherical clumps of cells,” said Benjamin Alessio, first author.
When Alessio visited the Birch Aquarium in San Diego, he was impressed by the sharpness of the boxfish’s intricate patterns. This pattern consists of purple dots surrounded by distinct hexagonal yellow lines with bold black spaces in between.
Turing’s theory alone would not be able to explain the sharp lines of this hexagon, he argued. But the pattern reminded Alessio of computer simulations he had done, in which the particles formed sharp lines. Alessio, a member of Gupta’s research group, wondered whether a process known as diffusiophoresis played a role in the formation of animal body patterns.
Diffusionophoresis occurs when a molecule moves through a fluid in response to a change, such as a difference in concentration, and accelerates the movement of another type of molecule in the same environment. The movement of molecules during diffusiophoresis, as Gupta and Alessio observed in their simulations, always follows a clear trajectory and produces patterns with sharp lines.
To see whether this plays a role in giving the animals patterns, Gupta and Alessio simulated the purple and black hexagonal patterns seen on boxfish skin using only Turing’s equation. The computer produces an image of blurry purple dots with a faint black outline.
Then the team modified the equation to include diffusiophoresis. The results turned out to be much more similar to the patterns seen in the fish.
The team’s theory suggests that when chemicals diffuse through tissue as Turing described, they also drag along pigment-producing cells via diffusiophoresis, much like soap draws dirt from laundry. These pigment cells form spots and lines with sharper outlines.
In the decades after Turing proposed his theory, scientists have used the mechanism to explain many other patterns in biology, such as the arrangement of hair follicles in mice and the ridges on the roofs of mammalian mouths.
“Our findings emphasize that diffusiophoresis may be under-viewed in the topic of (animal) pattern formation. This work not only has potential for applications in engineering and materials science but also opens up opportunities to investigate the role of diffusiophoresis in biological processes, such as embryo formation and tumor formation, Gupta said.
Watch the video “5 strange animals resulting from genetic engineering”
(nah/gas)
2023-11-21 00:30:35
#scientists #animals #motifs #bodies
