Using in ovo electroporation to transfect cells in avian somites

INTRODUCTIONIn ovo electroporation is an efficient approach for manipulating gene expression in multiple tissues of the chicken embryo, which greatly facilitates functional analysis of the role of specific genes during development. A successful protocol to deliver plasmid DNA into a specific tissue has to meet three basic criteria: high efficiency of transfection, low mortality of embryos, and localization of transfected cells. In this protocol, we describe an in ovo electroporation procedure for targeting muscle precursor cells in the lateral dermomyotome and axial skeletal precursor cells in the sclerotome of the somites of stage 15 chicken embryos. At this stage, the microinjection of DNA solution into individual somites is relatively easy, and the orientation of the electrodes directs the negatively charged DNA into the target tissues. The range of electrical current used is adjusted to maximize the transfection but minimize the mortality of the embryos.