PT  - JOURNAL ARTICLE
AU  - Sawyer, Jacob M.
AU  - Glass, Stephanie
AU  - Li, Trudy
AU  - Shemer, Gidi
AU  - White, Noor D.
AU  - Starostina, Natalia G.
AU  - Kipreos, Edward T.
AU  - Jones, Corbin D.
AU  - Goldstein, Bob
TI  - Overcoming Redundancy: an RNAi Enhancer Screen for 
Morphogenesis Genes in <em>Caenorhabditis elegans</em>
AID  - 10.1534/genetics.111.129486
DP  - 2011 Jan 01
TA  - Genetics
PG  - genetics.111.129486
4099  - http://www.genetics.org/content/early/2011/04/27/genetics.111.129486.short
4100  - http://www.genetics.org/content/early/2011/04/27/genetics.111.129486.full
AB  - Morphogenesis is an important component of animal development. Genetic redundancy has been proposed to be common among morphogenesis genes, posing a challenge to the genetic dissection of morphogenesis mechanisms. Genetic redundancy is more generally a challenge in biology, as large proportions of the genes in diverse organisms have no apparent loss of function phenotypes. Here, we present a screen designed to uncover redundant and partially redundant genes that function in an example of morphogenesis, gastrulation in Caenorhabditis elegans. We performed an RNAi enhancer screen in a gastrulation-sensitized double-mutant background, targeting genes likely to be expressed in gastrulating cells or their neighbors. Secondary screening identified 16 new genes whose functions contribute to normal gastrulation in a non-sensitized background. We observed that for most new genes found, the closest known homologs were multiple other C. elegans genes, suggesting that some may have derived from rounds of recent gene duplication events. We predict that such genes are more likely than single copy genes to comprise redundant or partially redundant gene families. We explored this prediction for one gene that we identified and confirmed that this gene and five close relatives, which encode predicted substrate recognition subunits for a CUL-2 ubiquitin ligase, do indeed function partially redundantly with each other in gastrulation. Our results implicate new genes in C. elegans gastrulation, and they show that an RNAi-based enhancer screen in C. elegans can be used as an efficient means to identify important but redundant or partially redundant developmental genes.