Roles for 147 embryonic lethal genes on C.elegans chromosome I identified by RNA interference and video microscopy

Early embryonic development involves complex events such as the regulation of cell division and the establishment of embryonic polarity. To identify g enes involved in these events, we collected four-dimensional time-lapse vid eo recordings of the first three cell divisions and analysed terminal pheno types after RNA interference of 147 embryonic lethal genes previously ident ified in a systematic screen of Caenorhabditis elegans chromosome I. Over h alf gave defects in early processes such as meiosis, the assembly or positi on of the first mitotic spindle, cytokinesis, and proper nuclear positionin g. For some phenotypic classes, the majority of genes are involved in a sha red biochemical process. In addition, we identified loss-of-function phenot ypes for genes of unknown function, but for which homologues exist in other organisms, shedding light on the function of these uncharacterized genes. When applied to the whole genome, this approach should identify the vast ma jority of genes required for early cell processes, paving the way for a gre atly improved understanding of these processes and their regulation at the molecular level.