Researchers Design Synthetic Microbe with Tiniest Possible Genome

After 20 years, a team of researchers has managed to design a synthetic microbe that has the smallest genome of a free-living organism. The cell, which has just 473 genes, could pave the way to a new generation of customized drugs, fuels, and other industrial products.

Researchers explained that their feat is a world’s first since no one has managed so far to create from scratch an artificial species that has no counterpart in nature. Past attempts to create a new species in a laboratory used genomes copied from other living organisms.

Paul Freemont of the Imperial College London who wasn’t involved in the research said that synthetic biology focuses on building entire genomes from scratch, rather than editing them.

Genome editing is a powerful tool used in various fields including medical research, agriculture, and industry. Currently, about 30,000 professionals practice genome editing’s most potent tool CRISPR.

Researcher Craig Venter and his team, however, have been working on designing an artificial organism since the mid-90s. Back then the team mapped the genetic code of Mycoplasma genitalium, a microbe that had one of the tiniest genome of a self-standing living organism.

Researchers found that the bacterium could function on 470 genes, but during experiments they switched off the unnecessary genes and found that only 375 were essential for the microorganism to function.

As a follow-up, the research team planned to replicate the experiment and create an artificial organism with just the 375 genes. By 2008, scientists were able to create an exact copy of the microbe’s genetic code by pairing chemically synthesized DNA snippets.

But because M. genitalium took too much time to synthesize, the team switched to Mycoplasma mycoides, whose genome they were able to synthesize and insert into another microorganism that was previously emptied of its own genetic code.

As a result, the team designed a group of synthetic cells dubbed JCVI-syn1.0 which were touted as a promising beginning of synthetic life. In the meantime, the White House called for a bioethics review of the research, while the Vatican challenged the team’s claims that they ‘created’ life. In fact, the group ‘created’ a genome by looking at an existing plan rather than building it from scratch.

But Venter’s team moved further. This year they designed an artificial species with the smallest genome ever: the JCVI-syn3.0 by removing the non-essential genes of M. mycoides via countless trial and error attempts and reducing its genome to 473 genes.

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