Geneticist Discusses Decoding His Own DNA

JEFFREY BROWN:

How much of who we are comes from our mother's genes? How much from our father's? And how do they interact to create the complex beings we are?

In 2000, scientists took their a landmark step in decoding the human genome, sequencing the order of billions of letters of DNA, using a blend of data from people with differing backgrounds. Now researchers have gone further by detailing the entire genetic makeup of one person and looking at the genes of both mother and father.

That one person is the scientist who published the work, geneticist Craig Venter.

Welcome to you.

CRAIG VENTER, Geneticist:

Thanks.

JEFFREY BROWN:

Explain to us a bit more about what you have done here and how it differs from what was done earlier.

CRAIG VENTER:

Well, in 2000, there were two different versions of the genome. The government-sponsored one took individual clones from, I think, 270 different people and put a composite together of what was a haploid genome, basically half of the genome.

At Celera, we did five different people. Mine was 60 percent of that sequence. But when we did the computer assembly of that, we, by definition, subtracted out a lot of the differences trying to get a consensus assembly, so both were flawed by what we know today, where we now have the complete genome of both sets of chromosomes that I inherited from my parents.

JEFFREY BROWN:

And the value of looking at one person — you — is what?

CRAIG VENTER:

Well, the value will only come by looking at each one of us. This is just the very first step. I think next year we'll probably see 30 to 50 individual genomes done, and hopefully a major escalation from there. But we had to start with one as a reference, and we built on the data that was generated earlier at Celera.

JEFFREY BROWN:

So this does give us a clearer view of what comes from our mother and what comes from our father?

CRAIG VENTER:

Well, it gives us a view of how much greater our complexity is than was previously thought.

JEFFREY BROWN:

In what way?

CRAIG VENTER:

Well, so when we compare — basically, each of us have two haploid genomes that we get from each parent. And it turns out even my two sets of chromosomes differ from each other by about five to seven times more than we thought before.

But if we were going to compare my genome, my two sets of chromosomes, to your two sets, human variation could be as much as 1 percent to 2 percent. So we went from 99.9 percent to maybe 99 percent or 98 percent. This is almost as much as we thought differed between humans and chimps, so it tells us that we differ a lot more.

I think this is good news that we're much more individualistic. As an individualist, I like that news.