Asymmetry plays a major role in biology in every scale: think of DNA spirals, the fact that the human heart is positioned to the left, our preference to use our left or right hand … A team from the Valrose Institute of Biology (CNRS / Inserm / Universite Cote Azur), in collaboration with colleagues from the University of Pennsylvania, showed that the individual protein induces spiral movement in another molecule. Through the domino effect, this causes the cells, organs and indeed the whole body to rotate, causing lateral behavior. This research was published in the journal Science November 23, 2018.
Our world is basically asymmetrical: think of a double spiral of DNA, an asymmetrical division of stem cells or the fact that the human heart is positioned on the left … But how do these asymmetries appear and are they linked?
At the Valrose Institute of Biology, a team led by CNRS researcher Stephane Noselli, who also includes Inserm and Universite Cote d 'Azur researchers, has been studying the right left asymmetry for several years to solve these enigmas. Biologists have identified the first gene that controls asymmetry in a common fruit fly (Drosophila), one of the organisms of the organism of favored biologists. More recently, the team has shown that this gene plays the same role in vertebrates: the protein it produces, Miosin 1D, controls winding or rotation of organs in the same direction.
In this new study, the researchers induced the production of Miosine 1D in normally symmetrical Drosophila organs, such as respiratory trachea. It was quite spectacular, it was enough to induce asymmetry at all levels: deformed cells, trachea that spin around, turning the whole body, and helicopter locomotive behavior among larvae of fly. Exceptionally, these new asymmetries are always evolving in the same direction.
To determine the origin of these cascading effects, biochemists from the University of Pennsylvania also contributed to the project: on a glass lid, they brought Miosin 1D into contact with the component of cytoskeleton (spine) or actin. They could notice that the interaction between the two proteins caused a spiral of actin.
In addition to its role in the asymmetry of right-left asymmetry in Drosophila and vertebrates, Miosin 1D appears to be a unique protein that is capable of induction of asymmetry and by itself on all scales, first at the molecular level, and then through the domino effect, on the cell, tissue and level behavior. These results indicate a possible mechanism for the sudden appearance of new morphological characteristics during evolution, such as, for example, the weaving of the snails. It seems that Miosin 1D has all the necessary characteristics for the emergence of this innovation, since only its expression is sufficient to induce twisting in all rocks.
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