One of the primary objectives of synthetic biology is how to control gene expression through gene switches based on a model borrowed from the digital world. The logic gate is what the digital technology uses to process input signals, creating circuits when input signals A and B are simultaneously present to produce output signal C.
Till recent times, Biotechnologists have tried to build such digital circuits with the help of protein gene switches in cells. But these have some grave disadvantages: there is a case of inadaptability, they work with only simple programming, and capable of processing one input at a time like a specific metabolic molecule.
Now, a team of researchers has discovered a way to use biological components to construct a flexible core processor, or central processing unit (CPU), that accepts different types of programming. The leader of this group is Martin Fussenegger, Professor of Biotechnology and Bioengineering at the Department of Biosystems Science and Engineering at ETH Zurich in Basel. The processor that the ETH scientists developed is based on a modified CRISPR-Cas9 system and basically can work with as many inputs as desired in the form of RNA molecules such as guide RNA.
The core of the processor has the form of a unique variant of the Cas9 protein. The CPU regulates the expression of a particular gene in response to input delivered by guide RNA sequences, which in turn makes a specific protein. Researchers have the potential of scalable programming circuits in human cells through this approach, like digital half adders, these consist of two inputs and two outputs with the possibility of adding two single-digit binary numbers.
Taking it further, the researchers created a biological dual-core processor which is similar to those in the digital world, by integrating two cores into a cell. For them to achieve this, they used CRISPR-Cas9 components from two different bacteria. Fussenegger delightedly added that they had created the first cell computer with more than one core processor.
In theory, though, this biological computer can be scaled up to any conceivable size, it is not extremely small. Fussenegger said that it is a microtissue with billions of cells, each equipped with its dual-core processor. Such computational organs could theoretically attain computing power that far outstrips that of a digital supercomputer, and using just a fraction of the energy.
He made emphasis on the fact that this cell computer may sound like a very revolutionary idea, but that is not the case. He talked about his next goal which is to integrate a multicore computer structure into a cell. He believes that this would have even more computing power than the current dual-core composition.
