Meet the 96-year-old Ottawa woman who contributed to the discovery of DNA's double helix

June Broomhead is easy to spot in a 1948 black-and-white photo of scientists working at the Cavendish Laboratory at Cambridge University. In a group of more than 100 men in suits and ties, she is one of just a few women.

A handful of the men pictured have won Nobel Prizes. Two of them, James Watson and Francis Crick, became household names after their discovery of the double-helix structure of DNA.

Broomhead's contributions to modern science, on the other hand, have largely been forgotten.

Broomhead, who took her husband George Lindsey's name, is now 96 and living in an Ottawa seniors' home. In the early 1950s, she married and quit her brief career as a top-notch physicist, beginning a new life as a stay-at-home mother to two children.

But Ottawa physician and molecular geneticist Alex MacKenzie says she played a crucial role in advancing our understanding of DNA. It was through reading her PhD thesis that Watson and Crick first realized how DNA is structured.

MacKenzie was astonished to discover Lindsey's role, and he wants her work to be recognized while she is still alive.

"It's like discovering the fifth Beatle is living next to you," he told The Sunday Edition's documentary producer David Gutnick.

A discovery 'seismic in its scale'

A couple of years ago, MacKenzie met Lindsey by chance at his mother-in-law's 90th birthday party. She mentioned her work in crystallography in the 1940s.   

"My curiosity was mildly piqued," he said.

"Cambridge is the mecca for crystallography — this rather arcane business of shining X-ray beams through crystals of structure and looking at the shadows that they cast and inferring the actual physical structure of how these things are put together."

When he got home from the party, MacKenzie "started Googling, and I found that her work had been central to Watson and Crick's epiphany."  

In 1948, Lindsey was using X-ray crystallography to figure out the structures of adenine and guanine, two of the four nucleobases that contribute to the structure of DNA. In 1951, she published an article explaining her findings.

Watson and Crick pored over her PhD thesis. They saw how she discovered that there was a regular pattern of hydrogen bonds between complementary nucleobases. The scientists immediately realized this could be the key to solving a problem.

"Within 48 hours, they had the model for the DNA double helix," said MacKenzie. "Watson had realized that the hydrogen bonds could serve as a 'zipper' for the two nucleic acid strands making up the double helix.

"It really was absolutely seismic in its scale."

Understanding her world, through science

Lindsey knows how crucial her research was. She's just not so sure she deserves the limelight.

She was pleased, nonetheless, on a recent afternoon, to welcome three University of Ottawa undergraduate science students into her apartment.

Lotty Pontones, Sophie Gregoire-Mitha and Sam Yee all take classes, during which they observe DNA. They are familiar with crystallography. When Lindsey told them that she had to do all of her own complex math calculations with a pen and paper, they shook their heads. Today, computers do all the calculations.

Lindsey told them how when she was a teenager, she discovered a book in her school library called The Evolution of the Idea of God, An Inquiry into the Origin of Religions by Grant Allen, that changed the way she thought about her place in the universe. She started seeing how science could change the way she understood the world. 

"I became an agnostic," Lindsey told her visitors. "We're microbes, no different from worms or frogs, and have no more rights than any of them."  

Yee looked at the photograph of Lindsey lost in the crowd of male scientists at the Cambridge lab. She asked Lindsey if she had felt she was their equal.

"I listened to them all talking," said Lindsey, "and I decided that men were better than women at science."

"How so?" an astonished Pontones asked. "You discovered something that I think 98 per cent of the people here would have dreamed of [doing] — discovering adenine and guanine."

"You deserved a Nobel."

"No, no," said Lindsey, shaking her head.

'Knotty crystallographic problems' left behind

Lindsey pulls out a fading, typewritten letter she received from Nobel laureate Sir Lawrence Bragg in 1952, in which he writes that he would love to work with her, should she ever be so inclined.

"I was very pleased to hear from you, and most amused to hear about your research into housework," Bragg wrote. "I only wish we had your help here at the present time."

"We badly need your hands to tackle knotty crystallographic problems, both experimental and theoretical. I wish all these things had come up while you were still with us; they would have been just in your line."

After obtaining her PhD in physics at Cambridge and doing postgraduate work at Oxford, she married Canadian scientist George Lindsey and followed him to Canada. She continued her research at the National Research Council for a few years in the early 1950s, and then she quit.

It's the little pieces that scientists like you put together to form this whole field.- Sam Yee

Lindsey tells her visitors she has no regrets about having given up her work.

"My career went because I had two children. I looked after them to the best of my ability, and they've done pretty well," she explained.

"I thank you for your work," said Yee. "It's the little pieces that scientists like you put together to form this whole field that now young women like me and Sophie and Lotty are really interested in studying. So thank you for your contribution."

"The older you get, the more you realize you're of little consequence," Lindsey replied.

"We come and we go."

MacKenzie doesn't want Lindsey to go before her crucial early contribution to the discovery of the double helix is publicly recognized.  

"This is something we should shout from the mountaintops," he said.

June Lindsey turns 97 on June 7.

Click 'listen' above to hear David Gutnick's documentary, "Who Do We Think We Are?"