by Matthew Woolf, Education & Outreach Executive
Over the past seventy years, molecular biology has transformed our understanding of life at its most fundamental level. Once, the mechanisms by which cells read the instructions in DNA, switch genes on and off, and generate or inherit mutations were deep mysteries behind a locked door with no key. But in the mid-twentieth century, a wave of groundbreaking discoveries began to unlock those secrets. Among the scientists who reshaped this new landscape, François Jacob stood out as a thinker and scientist whose ideas profoundly changed how we understand genes, regulation, and the logic of living systems.
Molecular genetics is now a gigantic, rapidly moving field, with hundreds of new discoveries every year aiding our understanding of the systems that make life tick. By understanding such processes, scientists can develop methods of modulating them to prevent disease, a possibility that is already being realised in many cases. Francois Jacob was at the forefront of this revolution, a key player in the era of research that made this new golden age possible.
Jacob was born in 1920 in Nancy, France to Simon and Therese Jacob. His grandfather and childhood hero was four-star general Albert Franck, the first Jewish General in the French army. He was raised Jewish and retained strong cultural ties to Judaism throughout his life, despite becoming an atheist immediately after his bar mitzvah.
Upon the Nazi invasion of France, Francois followed the lead of his hero to sign up with Charles De Gaull’s Free French Forces. Despite having only been able to complete two years of his medical degree, he served as a medic with the Second Armoured Division in Libya and Tunisia. His lack of experience was no obstacle, and despite enduring injury in a German air attack, he survived the war to earn France’s highest military decoration, the Cross of Liberation.
In the aftermath of his wartime heroics, Francois returned to complete his medical degree but prevented from achieving his dream of working in surgery due to his wartime injuries, he later recalled entering a period of aimless wandering in Paris. Persuaded by a cousin, he sought out work in the burgeoning science of microbiology. It was also during this time that he met his wife, the Pianist Lise Bloch.
In his first foray into the lab, he underwent a grand tour of essential techniques under the tutorage of Professor Trefouel, learning key skills in bacteriology, immunology and virology, before beginning work in the lab of Andre Lwoff.
It was here that his seminal breakthrough occurred. His colleague across the corridor, Jacques Monod was studying how bacteria produce enzymes only in response to certain stimuli, whilst himself and Lwoff were studying bacteria that could silence the expression of a virus (or Phage) despite the virus being embedded within the bacteria’s genome.
Jacob proposed that these seemingly unrelated systems shared their mechanism of regulation. He proposed common system in which genes were naturally blocked by repressor, which were removed by genes that were triggered by specific stimuli. They called this model of a regulatory circuit an ‘operon’ from the phrase ‘to operate’.
Jacob and Monod began a collaboration to prove this, and the project won them the Nobel prize in 1965. This model, and the method in which they discovered it, would provide the basis for study on a whole new frontier of gene regulation and many more complex models across the living world.
This project also resulted in the pair identifying the intermediate between DNA and the proteins they code for: messenger RNA (mRNA). They uncovered that, as the name implies, this molecule carries the code to the protein making factories within the cell where it was read.
This area of research enables us to understand how genes work, and as a result, investigate ways in which we can spot when something has gone wrong. This is something we’re very passionate about at Jnetics.
The locked door guarding the secrets to how life works is now open on the latch, with new discoveries pouring through. This Chanukah, we’re grateful to Jacob and others for cutting the keys.
