The ink can recognize light

That's the result that University of Wisconsin-Madison researchers reported on June 2 in the Proceedings of the National Academy of Sciences.

Research shows that light-emitting organs that some squid species use to disguise themselves from predators - usually fish on the seabed - can also recognize light. This finding may be a premise for future research that provides more insight into light control and recognition mechanisms.

Lead author Margaret McFall-Ngai, professor of microbiology and immunology at UW-Madison School of Medicine and Community Medicine (SMPH), explains: 'Evolution has a' kit 'and when needed Perform a certain function, such as light recognition, it uses this kit many times. In this case, the organ recognizes light, formed from different tissues from the eye during development, but uses the same eye-like protein to receive light '.

Studying squid for the past 20 years, McFall-Ngai and colleagues have come to the conclusion that the light-emitting organ is a natural symbiotic model - the interdependent relationship between the two animals in which Both species benefit.

Some squid species can recognize light through an organ other than their eyes.
New research shows that light-emitting organs that ink uses to disguise themselves from predators can also recognize light. (Photo: University of Wisconsin-Madison)

In this case, the glowing organ contains glowing bacteria that glow , and thereby protect the ink from predators. Meanwhile, squid provides shelter and nutrition for bacteria. Researchers at UW-Madison have long been interested in the ability of the ink-glowing organism - this ability allows the ink to emit light like on the surface of the sea so that deep predators cannot see see them.

McFal-Ngai said: 'So far, scientists believe that the tissues in the glowing organ only function to control the level and direction of the light emitted, without any role in receive light. We have demonstrated that E. scolopes squid has light-sensing tissue in the glowing organ. '

The researchers explained that the light-emitting organ in the ink has a molecular structure that responds to light signals. Molecular analysis shows that genes that produce important visual proteins are also expressed in glowing organ tissues, including genes similar to those in the retina. They also said that like in the retina, these proteins respond to light.

Co-author Nansi Jo Colley, professor of visual and visual sciences, said: 'We found that the light-emitting organ in the ink is capable of sensing light as well as emitting and controlling light'.

McFall-Ngai added: 'These tissues recognize the light of the environment, providing a mechanism to compare the external light with the light itself creates'.

McFall-Ngai's extensive research program on squid symbiosis aims to provide new insights into the effects of symbiosis on humans.

She said: ' We know that humans are home to millions of bacteria, throughout the components of eight of the 10 organ systems. These microbial communities are partners that help us stay healthy. '