Since the 1970s, scientists have pondered the power of genetic engineering to edit and rewrite the instruction book of life. Such technology has already demonstrated much power, if not the full potential initially envisioned. But now that’s changing, Tina Hesman Saey reports. CRISPR/Cas 9, a gene-editing system plucked from bacteria and developed just in the last few years, appears to be making many of the dreams of early genetic engineers not only possible, but also fairly fast and easy to attain.
Some of those dreams involve editing the genes not just of an individual but of an entire population to prevent disease, battle invasive species or protect crops. These tasks would involve what scientists call gene drives, edited genes that would incorporate themselves into an assemblage of cells, or mosquitoes, or fish, or weeds. Thanks to CRISPR, scientists’ plans for effective use of gene drives suddenly look feasible.
Not content to follow the 50–50 rule of Mendelian inheritance, gene drives propel their altered versions of genes into the next and subsequent generations of an organism. Based on natural “selfish” gene elements, these gene drives can spread an engineered change throughout a population in a relatively short time. In this way, mosquitoes may be made unable to carry the malaria parasite, or the problematic Asian carp may be tweaked so it could no longer survive in the Great Lakes.
Being good scientists, most gene-drive researchers want to pause and think about the implications of such powerful technology in a logical, reasoned way. Gene drives could alter the environment in unexpected ways. Eradicating an entire species would have ecological consequences. Such caution is commendable, even if it comes ahead of the technology. There are still, after all, hurdles to overcome. CRISPR is not always as specific in its targets as some reports suggest, for example. Biology is complicated. Nevertheless, the scientists are wise to consider, in a methodical way, both the power and peril of changing the biological world.