A simple method for gene expression in endo- and ectodermal cells in mouse embryos before neural tube closure

The lack of a widely accessible method for expressing genes of interest in wild-type embryos is the fundamental obstacle in understanding genetic regulation during embryonic development. In particular, only a few methods are available for introducing gene expression vectors into cells prior to neural tube closure, a period for the drastic development of many tissues. In this study, we present a simple technique for transferring vectors into the endo- and ectodermal cells of mouse embryos at E7.0 or E8.0 via in utero injection, without any specialized equipment. Using this technique, introduction of retroviruses can facilitate the labeling of cells in various tissues, including the brain, spinal cord, epidermis, and digestive and respiratory organs. As such, this technique can aid in analyzing the roles of genes of interest during endo- and ectodermal development prior to neural tube closure.