The Code Breaker: Jennifer Doudna, Gene Editing, and the Future of the Human Race

by Walter Isaacson

RNA, on the other hand, actually goes out and does real work. Instead of just sitting at home curating information, it makes real products, such as proteins.

A small segment of DNA that encodes a gene is transcribed into a snippet of RNA, which then travels to the manufacturing region of the cell. There this “messenger RNA” facilitates the assembly of the proper sequence of amino acids to make a specified protein.

the most fascinating type of proteins: enzymes. They serve as catalysts. They spark and accelerate and modulate the chemical reactions in all living things. Almost every action that takes place in a cell needs to be catalyzed by an enzyme.

Doudna used many tactics to create an RNA enzyme, or ribozyme, that could stitch together little RNA pieces. Eventually, she and Szostak were able to engineer a ribozyme that could splice together a copy of itself. “This reaction demonstrates the feasibility of RNA-catalyzed RNA replications,” she and Szostak wrote in a 1998 paper for Nature.

RNA is made up of very few chemicals, so it accomplishes complex tasks based on the different ways it is folded.

Enzymes are a type of protein. Their main function is to act as a catalyst that sparks chemical reactions in the cells of living organisms, from bacteria to humans.

CRISPR-associated (Cas) enzymes enable the system to cut and paste new memories of viruses that attack the bacteria. They also create short segments of RNA, known as CRISPR RNA (crRNA), that can guide a scissors-like enzyme to a dangerous virus and cut up its genetic material. Presto! That’s how the wily bacteria create an adaptive immune system!

tracrRNA performs two important tasks. First, it facilitates the making of the crRNA, the sequence that carries the memory of a virus that previously attacked the bacteria. Then it serves as a handle to latch on to the invading virus so that the crRNA can target the right spot for the Cas9 enzyme to chop.

The invention of gene editing required two steps. First, researchers had to find the right enzyme that could cut a double-strand break in DNA. Then they had to find a guide that would navigate the enzyme to the precise target in the cell’s DNA where they wanted to make the cut.

Two major milestones occurred in 1980. The U.S. Supreme Court ruled in favor of a genetic engineer who had derived a strain of bacteria capable of eating crude oil, which made it useful in cleaning up oil spills. His application had been rejected by the Patent Office on the theory that you could not patent a living thing. But the Supreme Court ruled, in a 5–4 decision written by Chief Justice Warren Burger, that “a live, human-made micro-organism is patentable” if it is “a product of human ingenuity.”1 Also that year, Congress passed the Bayh-Dole Act, which made it easier for universities to benefit from patents, even if the research was funded by the government.

Is there an inherent goodness to nature? Is there a virtue that arises from accepting what is gifted to us? Does empathy depend on believing that but for the grace of God, or the randomness of the natural lottery, we could have been born with a different set of endowments? Will an emphasis on personal liberty turn the most fundamental aspects of human nature into consumer choices made at a genetic supermarket? Should the rich be able to buy the best genes? Should we leave such decisions to individual choice, or should society come to some consensus about what it will allow?

But as we grope for a set of principles to include in our moral calculus, the distinction does point to a factor we should consider: favoring enhancements that would benefit all of society over those that would give the recipient a positional advantage.

Now, however, we may be ushering in a new eugenics—a liberal or libertarian eugenics, one based on free choice and marketed consumerism.

The foremost philosopher advocating this view is Julian Savulescu, a professor of practical ethics at Oxford. He coined the phrase “procreative beneficence” to make the case that it is moral to choose the best genes for your unborn children. Indeed, he argues, it may be immoral not to.

A liberal or libertarian genetics of individual choice could eventually lead us—just as surely as government-controlled eugenics—to a society with less diversity and deviation from the norm. That might be pleasing to a parent, but we would end up in a society with a lot less creativity, inspiration, and edge.

Once you’ve seen the face of someone with a genetic disease, she says, especially one like Huntington’s, it’s hard to support why we would refrain from gene editing.

The CRISPR-based tests can detect the presence of the RNA of a virus as soon as a person has been infected. But the antigen tests, which detect the presence of proteins that exist on the surface of the virus, are most accurate only after a patient has become highly infectious to others.

In the case of the COVID vaccine, the mRNA instructs cells to make part of the spike protein that is on the surface of a coronavirus.5

An RNA vaccine has certain advantages over a DNA vaccine. Most notably, the RNA does not need to get into the nucleus of the cell, where DNA is headquartered. The RNA does its work in the outer region of cells, the cytoplasm, which is where proteins are constructed.

As Steve Jobs emphasized when he built a headquarters for Pixar and planned a new Apple campus, new ideas are born out of serendipitous encounters. In-person interactions are especially important in the initial brainstorming of new ideas and the forging of personal bonds.

It took nature millions of years to weave together three billion base pairs of DNA in a complex and occasionally imperfect way to permit all of the wondrous diversity within our species. Are we right to think we can now come along and edit that genome to eliminate what we see as imperfections? Will we lose our diversity? Our humility and empathy? Will we become less flavorful, like our tomatoes?