Available online 29 August 2022, 104438

Nondiapause eggs produced by SG-ablation usable for genetic engineering.

Complete ablation of the SG caused reduction in egg laying in normally mating strain.

Injecting pilocarpine into the mated female reverted reduction in egg laying.

Eggs obtained have utility in transgenic silkworm production.

Eggs obtained have utility in genetic modification of the parthenogenetic strain.

Microinjection of genetic material into non-diapause eggs is required for genetic engineering of silkworms. Besides diapause could be useful for maintaining transgenic lines, a drawback of this technology is that most standard silkworm strains and experimental lines of interest produce diapausing eggs. Several approaches have been developed to abolish diapause but none are very efficient. Here, we investigated the ablation of the suboesophageal ganglion (SG) in female pupae, which is a source of the hormone required to trigger egg diapause, as a mean to abolish diapause. We showed that SG-ablation is a reliable method to produce nondiapause eggs. Additionally, the challenge associated with lower fecundity of females with SG ablation was resolved by injecting pilocarpine into the mated female. We also investigated the suitability of nondiapause eggs laid by SG-ablated females for transgenesis, targeted mutagenesis, and induction of parthenogenetic development. Our results demonstrated SG-ablation to be a useful and simple method for expanding the possibilities associated with genetic engineering in silkworms.

Silkworms

nondiapause eggs

suboesophageal ganglion ablation

pilocarpine

genetic engineering

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