The uses and implications of DNA technology

A number of laboratories, and particularly Fred Sanger’s at Cambridge University, developed techniques for sequencing DNA very rapidly. So, we go from 1977, when we were sequencing the very small pieces of DNA that determine the sequence of the base pairs, to the present day, when we can sequence an entire human genome in a single day for about a thousand dollars – which is really quite extraordinary.

Another technology that appeared somewhat later was the polymerase chain reaction. This uses the DNA polymerases that normally copy the genomes of cells, but you can use them in a test tube to make many millions of copies of DNA from a single molecule. You can take a single molecule of DNA and then amplify it using this polymerase chain reaction. It’s effectively DNA replication on steroids, but DNA replication of a very focused segment, as determined by the experimenter.

This PCR technology has been extremely important for society. It’s used not only for medicine and biological research but also for forensic evidence in court cases. It can show that people are guilty. It can also prove that people who were convicted of serious crimes did not, in fact, commit those crimes, and were condemned due to false testimony in their original trial.

From the beginning, scientists have been attuned to the ethical dilemmas of technologies such as recombinant DNA. When CRISPR/Cas9 emerged, there was an immediate recognition by the scientific community that this could raise serious ethical questions. These questions have been addressed not only by the scientific community but also by broader society, which is how it should be.

One important issue is the fact that, using CRISPR/Cas9, we can design a mutation at will and put it into a particular species, be it plant or animal. This technology has been enormously valuable. It’s been used, for example, to increase fruit yield in plants, and it’s something that my colleagues at Cold Spring Harbor Laboratory are doing all the time.

It bypasses the manual human selection of natural mutations that occur in the vast array of fruits and plants in the environment. Over the many thousands of years that humans have been engaged in agriculture, breeders have been able to select traits that increase fruit yield, fruit size or crop yield. Nowadays, we can go in and precisely change a specific gene to increase fruit yield, without relying on the randomness of all the mutations that exist in plants or animals.

Most scientists, myself included, would agree that using CRISPR/Cas9 to modify the DNA inside the adult cells of our body, the so-called somatic cells, to correct a mutation and potentially reverse a serious disease is entirely ethical. We’re using this technology right now.

The ethical dilemma arises when you go into the germ line – the cells that produce either eggs or sperm – and modify its DNA, which can be inherited forever across generations of people. Most scientists, myself included, do not support changing the germ-line DNA.

We now have DNA Learning Centers around the world, including in Australia, China, Europe, Singapore and throughout the United States. We’re trying to bridge a gap in public education. Our philosophy is that if you catch the children in middle and high school and not just select those who are interested in science, then you’re going to have generations of people growing up with an understanding of science and its associated technologies.

Another interesting thing is the scientific process itself, the way we go about doing science on a day-to-day basis. Scientists have to look at data, interpret it and come up with new ideas, interpretations and theories. The data gives us a path to follow.

Using data and logical thinking is actually a very good way to make decisions in society. So, another thing that scientists should do is transmit this logic and scientific way of thinking to society, which I think will counter a lot of the misinformation and rather kooky ideas that occur – as well as some decisions made by politicians, which we really can’t understand. If they use the scientific method to make decisions, that could improve society enormously.