Scientists are now contemplating the fabrication of a human genome, meaning they would use chemicals to manufacture all the DNA con tained in human chromosomes.
The prospect is spurring both intrigue and concern in the life sciences community because it might be possible, through cloning, to use a synthetic genome to create human beings without biological parents. The project, still in the idea phase, was discussed at a closed-door meeting on Tuesday at Harvard Medical School in Boston.
Organizers said the project could have a big scientific payoff and would be a follow-up to the original Human Genome Project, which was aimed at reading the sequence of the three billion chemical letters in the DNA blueprint of human life. The new project would involve not reading, but rather writing the human genome -synthesizing all three billion units from chemicals.
But such an attempt would raise ethical issues. Could scientists create humans with certain kinds of traits, perhaps people born and bred to be soldiers?
Or might it be possible to make copies of specific people? “Would it be okay to sequence and synthesize Einstein’s genome?“ Drew Endy, a bioengineer at Stanford, and Laurie Zoloth, a bioethicist at Northwestern University, wrote in an essay criticizing the proposed project. “If so how many Einstein genomes should be made and installed in cells, and who would get to make them?“ George Church, a professor of genetics at Harvard Medical School and an organizer of the proposed project, said there had been a misunderstanding. The project was not aimed at creating people, just cells, and would not be restricted to human genomes, he said. Rather it would aim to improve the ability to synthesize DNA in general, which could be applied to various animals, plants and microbes.“They’re painting a picture which I don’t think represents the project,“ Dr Church said in an interview.
He said the meeting was closed to the news media, and people were asked not to tweet because the project organizers had submitted a paper to a scientific journal, and were not supposed to discuss the idea publicly before publication. He and other organizers said ethical aspects have been amply discussed since the beginning.
Scientists and companies can now change the DNA in cells, for example, by adding foreign genes or changing the letters in the existing genes. This technique is routinely used to make drugs, such as insulin for diabetes, inside genetically modified cells, as well as to make genetically modified crops.
But synthesizing a gene, or an entire genome, would provide the opportunity to make even more extensive changes in DNA. The project doesn’t yet have funding.