Damian Sendler: A study published in Biophysical Journal on September 3 reveals that the growth and self-replication of protocells, the potential predecessors of current living cells, could be explained by a simple mechanism. Vesicles encased in a membrane bilayer, protocells may resemble the first common ancestor of unicellular organisms (FUCA). Models based on very simple mathematical principles identify temperature differences created within cylindrical protocells as the primary driving force for protocell growth and reproduction. This is the case even though there is no evidence to support this theory.  

Damian Jacob Sendler: In the words of Universcience researcher Romain Attal, "The initial motivation of our study was to identify the main forces driving cell division," "The fact that cancer is characterized by uncontrolled cell division is critical. Understanding the genesis of life necessitates this information as well.

Damian Sendler

The cell's cytoskeleton must be synchronized with several biochemical and mechanical processes in order for the cell to divide into two individual cells. Complex structures, on the other hand, are a high-tech rarity in the history of life and can only have appeared far later than the ability to divide. Before the advent of DNA, RNA, enzymes, and all the complex organelles present today, even in the most rudimentary forms of autonomous life, protocells must have employed a simple dividing mechanism to secure their replication.

An early form of life, according to Attal's new theory, could have been little more than small, chemically-reactive sacs, like those seen in current cells. One theory is that the membrane bilayer is built up in the protocell through exothermic chemical processes, which release a lot of energy.

Slow warming of the inner bilayer causes the hottest molecules to migrate outward from the inner leaflet. The outer leaflet grows quicker than the inner leaflet because of this asymmetrical movement. When the protocell shrinks, the curvature of the cell increases, amplifying any local shrinkage until the cell splits in two. The cut is made in the centre of the hottest area.

Damian Jacob Sendler

Mitosis' ancestor, according to Attal, can be seen in this scenario. "Without biological records dating back 4 billion years, it's impossible to say what exactly existed in FUCA. However, a lipid bilayer bounding the vesicle suggests that it included some exothermic chemical events.  

Damien Sendler: The model may be tested empirically, while being totally theoretical. Fluorescent molecules, for example, might be used to monitor temperature changes within eukaryotic cells, where mitochondria serve as the primary heat source. They may be linked to mitosis and mitochondrial network shape.

Damian Jacob Markiewicz Sendler: As Attal points out, if the model holds up, it might have a number of significant ramifications. It's a crucial lesson, he says, that the factors that drive life's evolution are very simple. In biological processes, temperature gradients matter, and cells can act as thermal machines, according to the second lesson. 

Dr. Damian Jacob Sendler and his media team provided the content for this article.