The great biologist Seymour Benzer passed away yesterday. If you know Benzer, it’s probably through Jonathan Weiner’s masterful book, Time, Love, Memory Time, Love, Memory, which focused on how Benzer discovered the influence of genes on behavior in fruit flies. But Benzer was one of those rare scientists who had enough time in his life for more than one great project. Before Benzer turned to fruit flies, he studied E. coli. And in studying that wonderful microbe, he helped to figure out what genes are in the first place.
In the early 1950s Benzer gave up a career in physics for biology after reading Erwin Schrodinger’s provocative book, What Is Life? At the time, molecular biology was in its infancy, and much of the inner workings of the cell was a mystery. Benzer took up molecular biology right around the time that James Watson and Francis Crick discovered the structure of DNA. Scientists were beginning to accept that DNA, not proteins, were the stuff of genes. Some scientists had even started to map the location of genes in chromosomes, particularly in E. coli. But those maps couldn’t reveal the structure within a gene.
Benzer discovered a tool to dissect genes–the viruses that infect E. coli. When a virus infects E. coli, it may soon find itself with another invader from a different viral strain. In 1946 scientists discovered that co-infecting viruses can mingle their genes. The new viruses that emerge from these hosts sometimes carry traits from both parental strains. A virus carrying a crippling mutation may be able to pick up a working copy of the gene from the other strain. It appeared that the chromosomes of viruses split apart when these recombinations took place. Benzer wondered if individual genes were sometimes torn in two in the process. Benzer realized he could test that possibility. He needed viruses that carried mutant versions of the same gene. The viruses might be able to swap parts of that gene to make a working copy. It would be like taking a pair of scissors to XIFE and LIFQ and pasting together LIFE.
Benzer chose a well-studied mutation that prevented viruses from infecting the K-12 strain of E. coli. He isolated viruses that carried the mutation, and allowed them to coinfect another strain of Escherichia coli. Once they had produced new viruses, he tried their offspring on K-12 again. As he had predicted, the mutant viruses could mix parts of the same gene to make a working version. Benzer then began to map the gene by crossing thousands of viruses and calculated the locations of dozens of its mutations. Just as physicists split the atom, Benzer split the gene.
As the geneticist Guido Pontecorvo wrote in 1958, “The analogy of the genetic material with a written message is a useful commonplace. The important change is that we now think of the message as being in handwritten English rather than in Chinese.” In Chinese, words are single pictograms. In English, words are not the fundamental unit–they are made from letters. Likewise, genes are made up of nucleotides of DNA. That may seem like an obvious truth today, but only thanks to Benzer.
Go Further
Animals
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Octopuses have a lot of secrets. Can you guess 8 of them?
- Animals
- Feature
Octopuses have a lot of secrets. Can you guess 8 of them?
Environment
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
History & Culture
- Gambling is everywhere now. When is that a problem?Gambling is everywhere now. When is that a problem?
- Beauty is pain—at least it was in 17th-century SpainBeauty is pain—at least it was in 17th-century Spain
- The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’
- Heard of Zoroastrianism? The religion still has fervent followersHeard of Zoroastrianism? The religion still has fervent followers
- Strange clues in a Maya temple reveal a fiery political dramaStrange clues in a Maya temple reveal a fiery political drama
Science
- NASA has a plan to clean up space junk—but is going green enough?NASA has a plan to clean up space junk—but is going green enough?
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- Can aspirin help protect against colorectal cancers?Can aspirin help protect against colorectal cancers?
- The unexpected health benefits of Ozempic and MounjaroThe unexpected health benefits of Ozempic and Mounjaro
- Do you have an inner monologue? Here’s what it reveals about you.Do you have an inner monologue? Here’s what it reveals about you.
Travel
- Follow in the footsteps of Robin Hood in Sherwood ForestFollow in the footsteps of Robin Hood in Sherwood Forest
- This chef is taking Indian cuisine in a bold new directionThis chef is taking Indian cuisine in a bold new direction
- On the path of Latin America's greatest wildlife migrationOn the path of Latin America's greatest wildlife migration
- Everything you need to know about Everglades National ParkEverything you need to know about Everglades National Park