Highly efficient targeted gene disruption in the silkworm, bombyx mori, using genome editing tools

Abstract

The silkworm, Bombyx mori, is a classic model organism in studies of insect genetics and physiology. As B. mori and most other lepidopteran species (moths and butterfl ies) are generally refractory to RNA interference (RNAi), it has been very difficult to conduct loss-of-function studies of genes in lepidopterans. However, recent advances in genome engineering tools, such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and the clustered regularly interspaced palindromic repeats/CRISPR-associated (CRISPR/Cas) system, have dramatically changed this situation. Although efficiency of targeted mutagenesis in B. mori was very low in an early experiment using ZFNs, recent studies using TALENs and CRISPR/Cas9 have induced highly efficient mutagenesis of the target genes in B. mori, even when the mutant phenotype was unknown. Genome editing tools facilitate sophisticated genetic manipulation and breeding of a wide variety of both beneficial and pest insects. This chapter summarizes recent advances in genome editing techniques in B. mori and proposes guidelines for experimental design and strategy for successful gene knockout experiments using this species.