Population scale nucleic acid delivery to Caenorhabditis elegans via electroporation

Genetic manipulations, like RNAi, CRISPR/Cas9- and array-based transgenesis depend on initial delivery of nucleic acids. Microinjection is effective for germline delivery, but limited by targeting each animal individually. We show that population-scale electroporation of dsRNA results in RNAi silencing throughout the worm, including in the germline. Electroporation of guide RNAs in Cas9 expressing worms can also induce gene disruptions. Together, these methods can be useful and expand the scale and scope of genetic methodologies developed for the C. elegans system. Abstract The free-living nematode Caenorhabditis elegans remains one of the most robust and flexible genetic systems for interrogating the complexities of animal biology. Targeted genetic manipulations, such as RNA interference (RNAi), CRISPR/Cas9- or array-based transgenesis, all depend on initial delivery of nucleic acids. Delivery of dsRNA by feeding can be effective, but the expression in Escherichia coli is not conducive to experiments intended to remain sterile or with defined microbial communities. Soaking-based delivery requires prolonged exposure of animals to high-material concentrations without a food source and is of limited throughput. Last, microinjection of individual animals can precisely deliver materials to animals’ germlines, but is limited by the need to target and inject each animal one-by-one. Thus, we sought to address some of these challenges in nucleic acid delivery by developing a population-scale delivery method. We demonstrate efficient electroporation-mediated delivery of dsRNA throughout the worm and effective RNAi-based silencing, including in the germline. Finally, we show that guide RNA delivered by electroporation can be utilized by transgenic Cas9 expressing worms for population-scale genetic targeting. Together, these methods expand the scale and scope of genetic methodologies that can be applied to the C. elegans system.