Mycoplasma |
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Is a rose still a rose if it doesn’t smell as sweet? Is a Mycoplasma capricolum still a Mycoplasma capricolum if it expresses a different genome? The answer to the first question is definitely “Yes” (especially if you could smell the roses I received on Mother’s Day). A paper published yesterday in Science confirms that the answer to the second question is a big fat “No”. Researchers at Maryland’s own J. Craig Venter Institute (JCVI) in Rockville in collaboration with their sister institute in San Diego are the first to successfully implant a new genome into a bacterial cell to create a new self-replicating bacteria that never existed before. In the most simplistic description, they created a unique new life.
Using a novel technique in which large DNA sequences were strung together in yeast, a 1.08 Mbp (Mega base pairs, where a base pair is one unit or nucleotide of double-stranded DNA) encoding all the necessary genes to make Mycoplasma mycoides JCVI-syn1.0 was synthesized. After synthesis, the circular chromosome was implanted into the nucleus of a similar species, Mycoplasma capricolum, for gene expression. This was not easy. After the first attempt failed, the researchers found a single mutation limiting proper gene expression. In their paper, the scientists recall several obstacles that had to be overcome: They needed to develop a method to extract large chromosomes from yeast, learn how to transplant these genomes into a recipient cell, and to choose a fast-growing recipient with the required gene expression machinery as a donor.
By synthesizing the DNA themselves, the researchers were able to include “markers” within the sequence. For example, if the genes were successfully expressed, the bacteria would be blue in color. Furthermore, they were able to leave a lasting mark on the DNA sequence by including strings of nucleotides (that when expressed into protein) spelled out an email address, the names of the scientists involved in the project, and a few famous quotations. [It isn't clear whether or not these proteins would actually be expressed. If only you could make an enzyme composed of a Shakespeare quote.]
This paper has raised some ethical and therefore political issues. President Obama has already asked the White House bioethics commission for a review of the issues to be provided to him in a report within 6 months, stating that the creation of a new genome raised “genuine concerns”. The application of this method for the synthesis of novel compounds using bacteria, such as biofuels, make this an important industrial topic as well. Can you patent an organism that you created? Would the laws that apply to genetically engineered crops where patents are in place apply to this as well?
In the last paragraph of the paper, the researchers write:
“We have been driving the ethical discussion concerning
synthetic life from the earliest stages of this work (25, 26). As
synthetic genomic applications expand, we anticipate that this
work will continue to raise philosophical issues that have
broad societal and ethical implications. We encourage the
continued discourse.”
Let the discourse begin.
