Electroporation-mediated somatic transgenesis for rapid functional analysis in insects

Transgenesis is a powerful technique for determining gene function; however, it is time-consuming. It is virtually impossible to carry out in non-model insects in which egg manipulation and screening are difficult. We have established a rapid genetic functional analysis system for non-model insects using a low-cost electroporator (costing under US$200) designed for somatic transformation with the piggyBac transposon. Using this system, we successfully generated somatic transgenic cell clones in various target tissues (e. g. olfactory neurons, wing epidermis, larval epidermis, muscle, fat body and trachea) of the silkworm Bombyx mori during development. We also induced stable and transient RNA interference (RNAi) using short hairpin RNA (shRNA)-mediating DNA vectors and direct transfer of small interfering RNAs (siRNAs), respectively. We found that these electroporation-mediated approaches could also be applied to the swallowtail butterfly Papilio xuthus and the red flour beetle Tribolium castaneum. Thus, this method could be a powerful genetic tool for elucidating various developmental phenomena in non-model insects.