Scientists learned how the predatory ciliate extended its “neck” tenfold

Scientists from the United States have solved the mystery of how the predatory infusoria Lacrymaria olor extends its “neck” 30 times more than the original length of the body, thanks to which it begins to resemble the character of Scottish folklore – Loch Ness. monster. The researchers’ discovery will help develop small medical robots that will find application in microsurgery.

Lacrimaria color – single-celled organism, predatory ciliate about 100 micrometers long. It lives in freshwater and hunts prey with a neck-like feeding apparatus that can extend to 1.2 millimeters in less than 30 seconds. This microorganism can extend its neck more than 20,000 times during its relatively short lifespan.

How this microorganism extended its “neck” to such a huge length has remained a mystery since the 16th century, that is, since scientists saw a predatory ciliate under a microscope.

American biophysicist Elliott Flaum (Eliott Flaum) and his colleague Manu Prakash (Manu Prakash) from Stanford University finally dealt with this problem. They examined the samples Lacrimaria colorA curved component was discovered in the subcellular components collected during one of the expeditions seven years ago, much like an origami structure, allowing the ciliate to quickly change the shape of its “neck”. The scientists reported the results of the study in an article published in the journal. Science.

Flaum and his colleague used a combination of real-time imaging, confocal and transmission electron microscopy in their study. These methods helped scientists obtain images of the external structure Lacrimaria color, cell membrane and inner cytoskeleton consisting of microtubules. It turned out that the cell membrane of infusoria consists of 15 layers, each of which twists around the cell, forming a spiral structure.

But how Lacrimaria color Does it extend and contract this region of the cell membrane without tangling? All “folds” remain stable thanks to the microtubule bands attached to them. Such a “fold” does not open (collapse) completely at once, but in parts: only one bend point on the “fold” opens or collapses.

When the bending points of each of the 15 “folds” are parallel to each other, the cell membrane opens in an orderly manner, causing the “neck” of the infusoria to extend more than 30 times compared to the original length of the organism’s body. . The reverse process leads to shortening of the “neck”, it returns to its original position.

According to scientists, stretching and bending occur due to the collision of hairs or cilia covering the entire surface of the cell. Although energy is required for this, this energy is very little as cell membranes can bend easily.

Prakash and Flaum are currently working on creating medical robots that use the “stretching technique.” Lacrimaria color. We are talking about miniature devices that can be expanded quickly, especially in narrow spaces. Such studies will be extremely useful in microsurgery.