miércoles, 16 de diciembre de 2015

Evelyn Witkin and the Road to DNA Enlightenment


Evelyn M. Witkin with her cat Jenny at home in Princeton, N.J. CreditLaura Pedrick for The New York Times
For decades Evelyn M. Witkin, professor emerita at Rutgers University, has been a towering figure in genetics. Recently she was awarded the Lasker Basic Medical Research Award for groundbreaking work into how DNA responds to damage, a process essential to all living organisms.

At 94, Dr. Witkin’s own DNA appears to be in excellent condition. We met at her townhouse not far from Princeton University. A condensed and edited version of that interview and a subsequent telephone conversation follows.

Q. When you were growing up in 1930s New York, what did you think you’d be doing with your life?
A. I thought I might become a biologist. Genetics wasn’t a separate field of study yet.

As an N.Y.U. undergraduate, I majored in biology; however, in my senior year, which was 1940, I joined a civil-rights protest. That changed the direction of my life.

Though N.Y.U. had blacks on sports teams, when the school went up against some universities in the South, they kept them home. Seven student leaders, myself included, circulated a petition protesting N.Y.U.’s acceptance of Southern racism. N.Y.U. responded by suspending us for three months. I could not graduate with my class. I lost the graduate assistantship they’d offered me for the following year.

DNA’s Defenses
Evelyn M. Witkin and Stephen J. Elledge received a Lasker award for insights into how cells respond to damaged DNA. 

So I went up to Columbia, walked into Theodosius Dobzhansky’s office and asked if I might study with him. He’d never had a female graduate student before and thought that would be pretty good, and he said, “Sure.

Why did you go to Dobzhansky, a founder of evolutionary genetics?
To be frank, it was because Professor Dobzhansky was Russian. I was interested in testing the theories of Trofim Lysenko, who asserted that genes didn’t exist. I thought Dobzhansky could read Lysenko in the original. Now, once I took Dobzhansky’s genetics class, I saw that Lysenko was a fraud or an ignoramus, or both.

One day in 1943, Professor Dobzhansky gave me an article by Salvador Luria and Max Delbruck proving for the first time that bacteria had genes. Reporting on it for Dobzhansky’s class, I jumped up and down with excitement. At the time, one of the big questions involved how genetic mutations occurred. Thanks to Luria and Delbruck, I now saw how we could use bacteria models to answer that.

So in the summer of 1944, Dobzhansky sent me to Cold Spring Harbor Laboratories, where he had connections and where they were pioneering bacterial genetics. I ended up staying until 1955.

Legend has it that on your first day there you made a significant discovery. True?
Yes. On my first day, my supervisor handed me a culture of E. coli bacteria, pointed to an ultraviolet lamp and said, “Go induce mutations.”

I took a million bacteria, placed them on petri dishes, and put them under ultraviolet lamps. When I came back the next morning, there was almost nothing left alive. The UV light doses apparently had been too strong. However, one petri dish had four colonies on it, which meant that four bacteria had survived what had killed everybody else.

At this point, I asked, “Why did they survive? Maybe a mutation made them resistant.

I next cultured and tested them. Sure enough, they could withstand 100 times more radiation than the parent strain. That created something of a splash among scientists at Cold Spring Harbor. It became the focus of my Ph.D. research and led to work that I and others did later on how DNA repairs itself.

What did you discover?
That DNA damage generates a signal that turns on a whole lot of other genes that are not active in the healthy cell. They don’t do anything unless the cell generates this S.O.S. signal. And when they are turned on, they make products that help cells survive. They repair damage.

Now, my co-winner of the Lasker Prize, Stephen Elledge, later picked up on what I found and applied it to higher organisms, including humans. It’s one connected story that couldn’t have been understood unless it had been worked out in bacteria first.

Your career began in a time when there were tremendous barriers against women entering the sciences. How were you able to do it?
I think it, in part, was because I had a lot of support from men.

My late husband, Herman Witkin, an experimental psychologist, was a real feminist. He believed my career was as important as his. For 10 years, he commuted four hours every day to his work in Brooklyn so that I could keep mine at Cold Spring Harbor. When our second child was an infant, he had a sabbatical. He wrote a book with the baby in his lap most of the time.

He loved being home with the children that year. He said he got so close to those kids and that it was the best thing ever.

Some time in the 1950s, Vannevar Bush, who’d headed the Carnegie Institution of Washington — Cold Spring Harbor’s laboratory was its department of genetics — sent his college-age granddaughter to talk to me about family and career. “The secret,” I told her, “is to have a husband like Herman Witkin and boss like Vannevar Bush.

How exactly was Bush helpful?
When I was pregnant with my first child, he came to my lab and said it was important to make scientific careers possible for women. What did I need? I told him, maternity leave and to return only part time. He said, “Done, and we’re not going to cut your salary because I know you’re going to do a full-time job.” That act alone made it possible for me to stay with my research.

Bush also was very supportive of Barbara McClintock. Before coming to Cold Spring Harbor, she’d had all the classical “women in science” experiences. She’d been a member of a graduate team at Cornell of three men. They got top-notch jobs as soon as they got their Ph.D.s. Barbara couldn’t.

She won the Nobel Prize for the work she did there. Were you friends?
Yes. She taught me to really get to know my bacteria. She had this belief that you had to have a feeling for the organism. I knew what she meant. You needed to get deep down with these bugs, get to know what goes on with them so that you could spot something unusual.

Why, in 1955, did you leave the research paradise that was Cold Spring Harbor?
Because it was bad for our family to have Herman commuting four hours daily. I moved my work to Downstate Medical Center in Brooklyn. Very early, I made a decision that if there was conflict between my work and family, the family came first.

In 1960 we both had sabbaticals to Paris. When François Jacob heard, he asked me to come work with him at the Pasteur. I turned him down because you don’t work with Jacob unless you use every cylinder you’ve got. My children were 8 and 11. They were going to be in a strange country, in a strange school. I couldn’t do it.

When the Nobel Prize in Chemistry was awarded this year, it went to researchers who had worked on DNA repair. Were you disappointed not to be included?
That’s an awkward question. I can imagine that readers who do not know me will not believe me, but I couldn’t have been disappointed because it never occurred to me that I would get a Lasker Award, let alone a Nobel.

ORIGINAL: NYTimes
By Claudia Dreifus
DEC. 14, 2015

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