Gary Ruvkun

Ruvkun discovered the let-7 microRNA in C. elegans, which, like Ambros's lin-4, turned out to be a tiny non-coding RNA that regulates gene expression by binding to messenger RNA from target genes. Critically, Ruvkun showed that let-7 is conserved across animal species including humans, proving that microRNAs are a universal regulatory mechanism, not just a worm peculiarity.

Ambros and Ruvkun worked independently on different genes—Ambros on lin-4 and Ruvkun on lin-14 and let-7—but they shared findings and realized together that both labs had discovered short regulatory RNAs. Their back-to-back papers in the journal Cell in 1993 jointly established the existence of microRNA as a new class of gene regulator.

Ruvkun is a professor of genetics at Harvard Medical School and a researcher at Massachusetts General Hospital in Boston. He has conducted his C. elegans and microRNA research there for decades, alongside his broader work on the genetic mechanisms of aging and development.

Caenorhabditis elegans is a tiny, transparent nematode worm with a fully mapped cell lineage and relatively small genome, making it ideal for studying how genes control development. Ruvkun and Ambros exploited its well-characterized developmental genetics to identify mutations in genes like lin-14 and let-7 that disrupted the worm's developmental timing, which led them to microRNA.