A team of scientists from MIT, the National Institute of Standards and Technology (NIST), and the J. Craig Venter Institute (JCVI) have created a synthetic single-celled organism that can divide and grow like a living cell. The new study builds on over a decade’s work in creating artificial lifeforms. The breakthrough could lead to designer cells that can treat disease or produce beneficial chemicals on demand from inside the body.
The mission began in 2010 when a JCVI team made the world’s first cell with a synthetic genome. They called it JCVI-syn1.0. They didn’t build JCVI-syn1.0 from scratch but with cells from mycoplasma – a rudimentary type of bacteria. They destroyed the DNA in the original cell and replaced it with computer-designed DNA synthesized in a lab. JCVI-syn1.0 is the first organism on the planet to have an entirely synthetic genome.
Then, in 2016, the scientists created JCVI-syn3.0, a follow-up version where the aim was to make the organism as simple as possible. It was the simplest living cell ever known, containing only 473 genes. For comparison: an E. coli bacterium has over 4,000 genes, and a human cell has approximately 30,000.
In the end, though, it was too simple because the cells weren’t effective at growing and dividing. The bacteria-like organism behaved strangely, producing cells with wildly different shapes and sizes. Some cells wouldn’t entirely separate, while others would form filaments. So, the team began stripping the organism down to its minimum genetic components, focusing on finding out which genes have to be re-included to get the organism to divide into cells of uniform shapes and sizes when growing.
After years of painstaking trial and error, they created the latest version, which they called JCVI-syn3A, which still has fewer than 500 genes but can divide properly into uniform orbs. They added 19 genes back into JCVI-syn3.0 to get JCVI-syn3A, including the seven needed for natural cell division.
Elizabeth Strychalski, a study co-author and leader of NIST’s Cellular Engineering Group, said:
We want to understand the fundamental design rules of life. If this cell can help us to discover and understand those rules, then we’re off to the races.
Identifying these genes is a milestone toward engineering synthetic cells that can do useful things and perform specified tasks on demand. But there’s still a ways to go because the team only knows what two of the seven genes do. To design and build a cell that behaves exactly as you want it to, you have to have a list of essential components and know-how they fit together.
Study co-author James Pelletier said:
Our goal is to know the function of every gene so we can develop a complete model of how a cell works.
The goal will be reached when they know what each gene in the organism does. For starters, they need to figure out what roles the other five genes of cell division play.
