Synthetic chromosome, made instead of natural, natural prototype differs from every sixth nucleotide, which, however, does not prevent the yeast feel normal.
To understand the structure of something, we first parse it into parts, analyze the “internal” and then trying to collect from the fact that there is something similar. If created earn the same as the original source, so we’re good and everyone understood correctly.
We long ago learned to disassemble the “parts” genomes of many different organisms, both bacteria and eukaryotes, both unicellular and multicellular. Moreover, we are able to tinker with the genomes of other people so that they continue to work, but a little differently based on our patches. The most common example – the introduction of a new gene (for example, a fluorescent protein gene) into a bacterium or a eukaryotic cell: a cell in this case does not die, but glows.
However, such modifications will still remain, so to speak, a natural basis – the gene integrated into the chromosome of the natural bacterial or eukaryotic cells. It is clear that sooner or later, the researchers want to create from scratch the entire chromosome as a whole, not just making an artificial copy, but a copy of the “revised and expanded.” It is managed and a large group of scientists led by Dzheyfa Bakey ( Jef Boeke ) from Johns Hopkins University and New York University (both – USA) in the journal Science , they describe seriously edited chromosome, they have created for the yeast cell.
Edited yeast chromosome; colored “pins” and marked the spot with white diamonds dot edition, yellow highlighted areas carved out of the chromosome. (Illustration Lucy Reading-Ikkanda.)
In yeast Saccharomyces cerevisiae sixteen chromosomes, for their experiment, the researchers chose the third. From 317,000 nucleotides 50000 undergone editing. At the same time, of course, change them, cut and paste is not random: the manipulation produced when it could greatly improve the process of chromosome assembly, first cut “jumping” genes associated with mobile elements, well, completely new sequence was introduced so that then they can be used to remove some have been targeted gene.
That is, in this hybrid chromosome laid additional opportunities for future editions.
This is certainly not the first time that scientists create artificial genome in 2010, similar work performed by Craig Venter and his institute. Mr. Venter – known figure in the world of genomic research and synthetic biology experiments and 2010, when he and his colleagues have managed to recreate the complete genome of the bacterium Mycoplasma mycoides , only strengthened his reputation. However, although the Mycoplasma genome at least three times greater than the third yeast chromosomes, researchers then it does not have any substantial revisions. As for the yeast, then there is, as already mentioned, editing undergone almost every sixth nucleotide.
Synthetic chromosome introduced into yeast and tested the viability of the resulting strain. Environmental conditions for 19 cells varied in different ways, but SynIII, named as a new strain was indistinguishable from the natural brother: and he and the other equally grown and bred in a variety of settings, whether modified acidity, DNA-damaging stress, etc .
Moreover, SynIII managed to push to sexual reproduction by cutting it a gene that prevents this type of reproduction.
Such a “chromosomal designer” – it’s not just art for art’s sake, scientists expect to learn with the help of some of the fundamental unit of the genome. DNA of living organisms contain many genes, but which ones are needed to a greater or lesser extent, what you can not live without which there is a hierarchy between them, how they interact with each other, etc. – all this we have yet to find out. And it can be just like these using artificial chromosomes that allow you to insert or delete genes at the request of the researcher.
And we have a yeast 6000 common genes, so it may help to know something about our own molecular genetic kitchen. Well, of course, do not forget about the very practical benefits: experimenting with synthetic chromosomes, we can create an organism with desired properties, which, say, with terrible force will produce some biofuels.
Prepared according to the Medical Center Lengon at New York University . Image on the screen saver belongs Shutterstock .