An Improved DNA Injection Method for Silkworm Eggs Drastically Increases the Efficiency of Producing Transgenic Silkworms

Abstract

To increase the efficiency of producing transgenic silkworms (Bombyx mori), we developed a new DNA injection system for injecting silkworm eggs at the pre-blastodermal stage. In the new system, the tip of a glass capillary can be precisely guided into a hole made with a tungsten needle and inserted into the egg. This way, DNA can be injected into eggs more quickly and easily compared to previously used injection methods. In addition, it allows for a more precise injection into the primordial germ cell. Therefore, our system greatly increases the efficiency of transgenic silkworm production.