"A Role for the RNase III Enzyme DCR-1 in RNA Interference and Germ Line Development in C. elegans".

¹ Department of Biochemistry and Howard Hughes Medical Institute, University of Utah, 50 North Medical Drive, Room 211, Salt Lake City, UT 84132, USA.

^* To whom correspondence should be addressed. E-mail: bbass@howard.genetics.utah.edu.

An early event in RNA interference (RNAi) is the cleavage of the initiating double stranded RNA (dsRNA) to short pieces, 21-23 nucleotides in length. Here we describe the first null mutation in dicer-1 (dcr-1), a gene proposed to encode the enzyme that generates these short RNAs. We find that dcr-1(-/-) animals have defects in RNAi under some, but not all, conditions. Mutant animals have germ-line defects that lead to sterility, suggesting that cleavage of dsRNA to short pieces is a requisite event in normal development.

1. Ambros V, "Dicing Up RNAs", Science vol. 293, no. 5531, pp. 811-813 (August 3, 2001).