I am writing to correct a statement in the informative News Feature "A silence that speaks volumes" (Nature 404, 804; 2000). The work from my laboratory, published in the paper by Florence Wianny and myself, has shown that dsRNA interference can be effective in both the mouse oocyte and early embryo (see Wianny, F. & Zernicka-Goetz, M. Nature Cell Biol. 2, 70–75; 2000). We have successfully used the technique to prevent expression of the c-mos gene during oocyte maturation, and of the E-cadherin gene to interfere with formation of the blastocyst when delivered to the one-cell-stage zygote. ; © 2000 Nature Publishing Group.