Nine years ago, biologists announced that they had “created” the first synthetic chromosome of this microscopic yeast. Today, the same group of biologists have arrived at a yeast in which more than 50% of the genome was created in the laboratory.
Or at least a lot of it in the lab. Of the 16 chromosomes of this brewer’s yeast (Saccharomyces cerevisiae), six and a half chromosomes were “edited and synthesized” in the laboratory, and another was formed from fragments of other parts of the yeast genome (its only, this “XI” chromosome). represents 660,000 base pairs). The microorganism in question can live and reproduce under controlled conditions.
The international consortium of researchers from different institutions on four continents called Sc2.0 (Synthetic Yeast Genome Project) has been working on this project for 15 years, which aims to create a living organism that does not exist in nature. But even more: a living being that could produce something other than beer if necessary – for example medicine or fuel (in fact, yeast is already used in industry to produce chemical or biochemical substances). The branch of biology is called Synthetic Biology and its first congress will take place in 2004. The announcement was the subject of no fewer than nine articles in the journals Cell and Cell Genomics this week.
This synthetic biology itself arose from two advances that have occurred in the last 20 years: on the one hand, DNA sequencing techniques that have become increasingly faster and increasingly inexpensive; and, on the other hand, the ability to create genes in the laboratory rather than transferring them from one organism to another. But even with these “assets,” the work remains enormous, as evidenced by these 15 years to reach half the genome of an organism made up of a single cell. The goal of getting this microscopic fungus to produce medicine, for example, still lies in the uncertain future.
Scientific papers published over the decade have shown geneticists trying to learn more about seemingly useless genes – those that don’t code for proteins or repeat. Through trial and error, experts are trying to figure out the true functions of these genes or, conversely, what would be the “minimal” genome that would still allow such an organism to live and reproduce.
During this time, viruses and bacteria were built entirely from synthetic genomes. However, compared to yeasts, they have extremely simple genetic structures: for example, the bacterium E. coli only has one chromosome. In addition, compared to these other experiments, the experiment with yeast is the first on a living organism in the category of eukaryotes: that is, those that, like all animals and plants, have a cell consisting of a nucleus in which the genetics are located Material is stored. The next step, this consortium expects, will be to try to develop a yeast that is, as the industry puts it, 100% synthetic.