Newfound RNA suggests a hidden complexity inside cells
It started with worms that just would not grow up. In the early 1990s, Victor Ambros and his colleagues were conducting a gene hunt. In particular, they were searching for the gene that was mutated in a perplexing strain of Caenorhabditis elegans, the small nematode whose development many biologists study.
This genetic change Ambros hunted had apparently disrupted the worms' developmental timing.
In normal strains, worms pass through four larval stages as they mature into fertile adults. But members of the mutant strain get stuck at the first stage. They would molt, but instead of moving on to the second larval stage, they simply repeated the first stage. The larvae kept growing larger but never became full-fledged adults.
Ambros' team painstakingly homed in on the gene responsible by adding pieces of DNA from normal C. elegans back into the mutant worms. If a DNA sequence restored full development, it presumably harbored a working copy of the ge