Movement and the ability to divide are two fundamental traits of living cells. The origin of these abilities could rely on very simple physical mechanisms, which have been simulated by scientists of the International School for Advanced Studies (SISSA) of Trieste in a study just published in Physical Review Letters.
Luca Giomi and Antonio DeSimone have reproduced motility in their models, by acting on a single parameter until they caused the “cells” to divide spontaneously without the action of external forces. The result is a step forward in the creation of functioning artificial cells, as well as a better understanding of the first passages from which life on our planet developed.
Droplets of filamentous material enclosed in a lipid membrane: these are the models of a “simplified” cell used by the SISSA physicists Luca Giomi and Antonio DeSimone, who simulated the spontaneous emergence of cell motility and division – that is, features of living material – in inanimate “objects”. The research is one of the cover stories of the April 10th online issue of the journal Physical Review Letters.
Giomi and DeSimone’s artificial cells are in fact computer models that mimic some of the physical properties of the materials making up the inner content and outer membrane of cells.
The two researchers varied some of the parameters of the materials, recording what happened: “our ‘cells’ are a ‘bare bones’ representation of a biological cell, which normally contains microtubules, elongated proteins enclosed in an essentially lipid cell membrane”, explains Giomi, first author of the study. “The filaments contained in the ‘cytoplasm’ of our cells slide over one another exerting a force that we can control”.
The force exerted by the filaments is the variable that competes with another force, the surface tension that keeps the membrane surrounding the droplet from collapsing. The generates a flow in the fluid surrounding the droplet, which in turn is propelled by such self-generated flow. When the flow becomes very strong, the droplet deforms to the point of dividing. “When the force of the flow prevails over the force that keeps the membrane together we have cellular division”, explains DeSimone, director of the SISSA mathLab, SISSA’s mathematical modelling and scientific computing laboratory.
“We showed that by acting on a single physical parameter in a very simple model we can reproduce similar effects to those obtained with experimental observations” continues DeSimone. Empirical observations on microtubule specimens have shown that these also move outside the cell environment, in a manner proportional to the energy they have (derived from ATP, the cell “fuel”). “Similarly, our droplets, fuelled by their ‘inner’ energy alone – without forces acting from the outside – are able to move and even divide”.
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“Acquiring motility and the ability to divide is a fundamental step for life and, according to our simulations, the laws governing these phenomena could be very simple. Observations like ours can prepare the way for the creation of functioning artificial cells, and not only”, comments Giomi. “Our work is also useful for understanding the transition from non-living to living matter on our planet. The development of the early forms of life, in other words.”
Chemists and biologists who study the origin of life don’t have access to cells that are sufficiently simple to be observed directly. “Even the simplest organism existing today has undergone billions of years of evolution”, explains Giomi, “and will always contain fairly complex structures. Starting from schematic organisms as we do is like turning the clock back to when the first rudimentary living beings made their first appearance. We are currently starting studies to understand how cell metabolism emerged”.
I found this blog to be very insightful. To me the most amazing aspect of this blog was the realization that technology has become such a significant factor in helping to unravel the mysteries of our cells, their existence and how they have evolved over time.
To answer one of the previous bloggers’ question, I do believe that the creation of fully functional artificial cells would be able to contribute a great deal to the medical world by predicting and preventing certain reactions that could lead to serious defects or mutations inside a cell. Experiments conducted on these cells could provide answers scientists have been looking for and therefore solve some health issues that have been a problem in the past.
The fact that these artificial cells could also expand our knowledge of the universe as a whole by filling the gaps left in the explanations of how we came to be is also a really interesting aspect for me. The subject of how non-living matter transformed into living matter is one many have mere suggestions about and if scientists could provide us with clearer understandings and conclusions about the universe using these artificial cells I believe that it would bring us much closer to the truth about life,existence and how it all started.
To question what such a discovery will have on everyday life is little ignorant in my opinion. If you did read the article it mentions something along the lines of a cell being able to be studied more easily and prove certain theories right or wrong. As mentioned above, the evolution from the first beings resulted in the cells we are familiar with today to be fairly complex and that is not the easiest thing to study. With this discovery we are able to thus view one minute part or function of the cell without all the other structures interrupting such research. Even at such a small scale, this is a major breakthrough for the scientific community and might as well take several years to assist mankind in any particular way.
A.K 14027250
To answer the question of the previous blogger , cells divide to assure that the organism containing these cells keeps on growing , or , when fully grown – maintains bodily functions by assuring that all of the cells in the organism’s keeps functioning properly . When cells are unable to divide , the organism containing them will not be able to maintain functionality and growth . The part of the cytoskeleton participating in cell division are known as actin filaments , microtubules , and motor proteins which together gives the cell the ability to move and divide . The amount of microtubules contained in the cell is determined by the centrosome . When cell division occurs , the microtubules spontaneously starts forming( controlled by the centrosome ) in the direction of the periphery of the cell , pressing against the phospholipid bilayer of the cell , causing the plasma-membrane to bulge out . Extension of actin filaments to support the new , unsupported bulged part of the cell is the next step in cellular devision . When the bulge is properly supported , motor proteins carry cell organelles and essential parts of the cell to the unfilled new intracellular space . This process establishes movement of cells or , if microtubules keep on extending and stretching the phospholipid bilayer , the phospholipid bilayer will break and reform because of hydrophobic interactions , producing one new daughter cell , thus , division of the cell .
Thank you
Elri van den Berg
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What effect will spontaneously dividing cells have on our lives?How will cells dividing spontaneously help us understand the early life forms?
You say that “our” cells is a representation of a biological cell, which normally contains microtubules, elongated proteins enclosed in an essentially lipid cell membrane” and that you are currently doing experiments on cells to divide spontaneously. What are the benefits for the everyday person on street if these cells divide? Will some illnesses and diseases be “cured” in this way and will health issues that can not be solved be something of the past?