Scientists Created a "Minimal Cell" with only 473 genes

     In 1984, mycoplasms were proposed to understand the basic principles of life since they are simple and capable of autonomous growth. Specifically Mycoplasma genitalium was focused since it has a mere 525 genes, but upon further study only 250 were essential. Thus, this provoked the idea that it should be possible to create a minimal cell with less genes than the natural cell. Though the cells can survive with a minimal amount of genes, some genes have some importance that promote growth. It becomes a trade off of being a smaller cell to also have a decreased growth rate. The scientists were able to produce JCVI-syn3.0 with only 473 genes and it still has the abilities to synthesize all of its necessary macromolecules. The scientists were also surprised to find that 149 of the genes had unknown biological functions which presents the question: is there any other functions that are undiscovered and necessary for life?

     I find it interesting how cells are able to function with such a minimal amount of genes to begin with because there are so many functions it needs to accomplish to survive. Based off this research it is entirely possible for this research to be applied to humans, which could yield for interesting results because this could lead to malicious genes to be removed from the genome as well as unnecessary ones. Further study of JCVI-syn3.0 will also be interesting since scientists may discover new functions of genes and how they are essential to life.

Figure 1. (A) The cycle of genome design (B) Comparison of base pairs between JCVI-syn1.0 (blue) and JCVI-syn3.0 (red) (C) Cluster of JCVI-syn3.0 cells

Microbes With Limited DNA May Reveal Secrets of Life

Scientists recently deleted nearly half the genes in a microbe, which created a stripped-down version that still fully functions. This achievement can potentially reveal secrets of life and how life works. This finding may also help researchers create new bacteria specially made for pumping out medicine and other valuable substances. 

This newly created bacterium contains less genetic information than any other natural free-living counterpart. This bacterium had 531,000 DNA building blocks, and 473 genes, while humans have more than three billion DNA building blocks, and more than 20,000 genes. Unfortunately, scientists still consider this simple microbe as a mystery, because they are still unsure what one third of their genes actually do. 

Some of these mystery genes could possibly reveal unknown fundamental processes of life, which Clyde Hutchinson III and J. Craig Venter said in an interview, the two authors of a paper on the project release in the journal Science. The brand new genome, or DNA code, is contained in a brand new bacterium called JCVI-syn3.0. 

This is not the only set of minimal genes needed for life itself. If the researchers had paired DNA from a different bacterium, they probably would have gotten a different set of genes. The minimum genome an organism needs would depend on its environment in which it lives. Additionally, the genome includes genes that are not essential to life, because they help the bacteria populations grow fast and this makes it easy for lab work. 

A goal of this work is to find out what every single gene living cell does, which would give a very good understanding of how cells work and function. Another goal is to use minimal-DNA microbes as a chassis for adding genes to make the organisms produce medicines, and other substances for uses like nutrition and agriculture. 

This work began with a man-made version of a microbe found in sheep, called M. mycoides, which has about 900 genes. The scientists identified 428 non-useful genes, and built their genome without it but was still complete enough to let the bacterium survive. 

I believe this work is only the beginning to a huge finding in genetics. With this information, scientists can get closer to defining each and every gene in a living cell and understand what the function is of each. It is hard to believe that more than half of the genes in a microbe could be non-essential, yet not understood. With this study, there will be advances in medicine and public health research.