Using RNAi to investigate orthologous homeotic gene function during development of distantly related insects

Gene product distribution is often used to infer developmental similarities and differences in animals with evolutionarily diverse body plans. However , to address commonalties of developmental mechanisms, what is really neede d is a method to assess and compare gene function in divergent organisms. T his requires mutations eliminating gene function. Such mutations are often difficult to obtain, even in organisms amenable to genetic analysis. To add ress this issue we have investigated the use of double-stranded RNA interfe rence to phenocopy null mutations. We show that RNA interference can be use d to phenocopy mutations of the Deformed orthologues in Drosophila and Trib olium. We discuss the possible use of this technique for comparisons of dev elopmental mechanisms in organisms with differing ontogenies.