Transcription activator‐like effector nuclease ( TALEN) ‐mediated female‐specific sterility in the silkworm , B ombyx mori

Engineering sex‐specific sterility is critical for developing transgene‐based sterile insect technology. Targeted genome engineering achieved by customized zinc‐finger nuclease, transcription activator‐like effector nuclease ( TALEN) or clustered, regularly interspaced, short palindromic repeats/Cas9 systems has been exploited extensively in a variety of model organisms; however, screening mutated individuals without a detectable phenotype is still challenging. In addition, genetically recessive mutations only detectable in homozygotes make the experiments time‐consuming. In the present study, we model a novel genetic system in the silkworm, B ombyx mori , that results in female‐specific sterility by combining transgenesis with TALEN technologies. This system induces sex‐specific sterility at a high efficiency by targeting the female‐specific exon of the B . mori doublesex ( B mdsx) gene, which has sex‐specific splicing isoforms regulating somatic sexual development. Transgenic animals co‐expressing TALEN left and right arms targeting the female‐specific B mdsx exon resulted in somatic mutations and female mutants lost fecundity because of lack of egg storage and abnormal external genitalia. The wild‐type sexual dimorphism of abdominal segment was not evident in mutant females. In contrast, there were no deleterious effects in mutant male moths. The current somatic TALEN technologies provide a promising approach for future insect functional genetics, thus providing the basis for the development of attractive genetic alternatives for insect population management.