In 1993, Ambros and his co-workers
Rosalind Lee and
Rhonda Feinbaum reported in the journal
Cell that they had discovered single-stranded non-protein-coding regulatory
RNA molecules in the organism
C. elegans. Previous research, including work by Ambros and Horvitz, had revealed that a gene known as
lin-4 was important for normal larval development of
C. elegans, a nematode often studied as a model organism. Specifically,
lin-4 was responsible for the progressive repression of the protein
LIN-14 during larval development of the worm; mutant worms deficient in
lin-4 function had persistently high levels of LIN-14 and displayed developmental timing defects. Ambros and colleagues hypothesized and later determined that
lin-4 could regulate LIN-14 through binding of lin-4S to these sequences in the
lin-14 transcript in a type of antisense RNA mechanism. In 2000, another
C. elegans small RNA regulatory molecule,
let-7, was characterized by the Ruvkun lab and found to be conserved in many species, including vertebrates. He was elected a Fellow of the American Academy of Arts and Sciences in 2011. In 2024 he shared the Nobel Prize in Physiology and Medicine with Gary Ruvkun "for the discovery of microRNA and its role in post-transcriptional gene regulation". ==Awards==