Pronuclear Microinjection of One-Cell Embryos.

Generating a transgenic or gene-modified mouse requires the introduction of exogenous reagents into an early-stage embryo. The mouse one-cell embryo or zygote possesses two pronuclei, representing the genetic contribution of the sperm and oocyte. Traditional transgenic mice are generated by injecting a DNA solution containing a purified transgene construct into the male pronucleus, generally the larger of the two pronuclei. Similarly, gene-editing reagents such as ZFNs, TALENs, and CRISPR RNAs are introduced into zygotes in the same manner, making this technique applicable to a wide variety of projects. This chapter presents the procedures for pronuclear microinjection.