Cover image

Cover Large-scale RNAi studies in C. elegans have revealed many genes required for embryogenesis. In this tableau, embryos of different colors represent potential variations in phenotypic response elicited by RNAi of the same gene. Analysis of a compendium of data on ovary-enriched genes from several large-scale RNAi projects suggests that genes with partially penetrant embryonic lethal phenotypes reflect inherent stochasticity in the response of a complex system to the loss of gene function, and may thus provide clues about the evolution of genetic networks. (Cover design by Fabio Piano and Anita Fernandez; adult C. elegans image courtesy of Michael Brauchle. [For details, see Fernandez et al., 250–259.])