TL;DR: Venter and his collaborators originally set out to design a stripped-down genome based on what scientists knew about biology.
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With the right tools finally in hand, the researchers designed a set of genetic blueprints for their minimal cell and then tried to build them. Yet “not one design worked,"
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So the team took a different and more labor-intensive tack, replacing the design approach with trial and error. They disrupted M. mycoides’ genes, determining which were essential for the bacteria to survive.
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Venter is careful to avoid calling syn3.0 a universal minimal cell. If he had done the same set of experiments with a different microbe, he points out, he would have ended up with a different set of genes.
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In fact, there’s no single set of genes that all living things need in order to exist.
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They found that not a single gene is shared across all of life. “There are different ways to have a core set of instructions,”
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Venter’s minimal cell is a product not just of its environment, but of the entirety of the history of life on Earth.
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He and others are trying to make more basic life-forms that are representative of these earlier stages of evolution.
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Some scientists say that this type of bottom-up approach is necessary in order to truly understand life’s essence. “If we are ever to understand even the simplest living organism, we have to be able to design and synthesize one from scratch,”
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“We are still far from this goal.”
As @sixQuarks has already written, finding the minimal amount of genes when there are 175 unknown ones and you don't know anything about their dependencies and relationships seems to be pretty much impossible.
> In fact, there’s no single set of genes that all living things need in order to exist. ... They found that not a single gene is shared across all of life.
That's the most interesting point to me, I deeply believed that organisms share the same basic set of genes.
As @sixQuarks has already written, finding the minimal amount of genes when there are 175 unknown ones and you don't know anything about their dependencies and relationships seems to be pretty much impossible.
> In fact, there’s no single set of genes that all living things need in order to exist. ... They found that not a single gene is shared across all of life.
That's the most interesting point to me, I deeply believed that organisms share the same basic set of genes.