Victor Ambros, an alumnus of MIT, and Gary Ruvkun, who completed his postdoctoral training at the same institution, have been awarded the 2024 Nobel Prize in Physiology or Medicine, as announced today by the Royal Swedish Academy of Sciences in Stockholm.
Ambros, currently a professor at the University of Massachusetts Chan Medical School, and Ruvkun, a professor at Harvard Medical School and Massachusetts General Hospital, received the prize for their pioneering work on microRNA, a group of small RNA molecules crucial for gene regulation.
The Nobel committee highlighted their groundbreaking discovery that revealed a novel principle of gene regulation vital for multicellular organisms, including humans. It is now understood that the human genome encodes for over a thousand microRNAs. This unexpected finding has opened new avenues for understanding gene regulation and is significant for the development and functioning of organisms.
In the late 1980s, both Ambros and Ruvkun conducted research as postdoctoral fellows in the lab of H. Robert Horvitz at MIT, who was awarded the Nobel Prize in 2002. During their time in Horvitz’s lab, they began their investigations into gene control in the roundworm C. elegans, examining mutant strains named lin-4 and lin-14 that exhibited developmental timing defects.
In the early 1990s, while Ambros was a faculty member at Harvard, he made a groundbreaking discovery that the lin-4 gene, rather than coding for a protein, produced a short RNA molecule that inhibited the expression of lin-14. Concurrently, Ruvkun was studying these genes in his lab at Massachusetts General Hospital and Harvard, discovering that lin-4 regulated lin-14 expression by blocking the translation of the protein, rather than by preventing its transcription into messenger RNA.
Their collaborative efforts led to the realization that lin-4’s sequence was complementary to parts of lin-14, demonstrating a previously unknown mechanism for gene regulation. Their findings were published in two articles in the journal Cell in 1993.
In an interview, Ambros acknowledged the important contributions of his collaborators, including Rosalind “Candy” Lee and Rhonda Feinbaum, who helped characterize the lin-4 microRNA and were co-authors on one of the papers.
In 2000, Ruvkun identified another microRNA called let-7, present across the animal kingdom, leading to the discovery of more than 1,000 microRNA genes in humans today.
The Nobel citation emphasized that Ambros and Ruvkun’s unexpected findings in C. elegans uncovered a new dimension of gene regulation essential for all complex life forms.
Born in New Hampshire and raised in Vermont, Ambros completed his PhD at MIT under Nobel laureate David Baltimore. He previously taught at Dartmouth College before joining the University of Massachusetts Chan Medical School in 2008. Ruvkun, a graduate of the University of California at Berkeley, obtained his PhD at Harvard before joining Horvitz’s lab at MIT.