The molecular mechanisms that time development are now being deciphered in
various organisms, particularly in Caenorhabditis elegans. Key recent findi
ngs indicate that certain C. elegans timekeeping genes are conserved across
phyla, and their developmental expression patterns indicate that a timing
function might also be conserved. Small regulatory RNAs have crucial roles
in the timing mechanism, and the cellular machinery required for production
of these RNAs intersects with that used to process double-stranded RNAs du
ring RNA interference.