转基因技术是一项实现家蚕基因功能鉴定与素材创新等基础和应用研究的重要技术，但该技术本身的安全性问题却成了限制转基因家蚕应用的主要瓶颈，这方面的研究基础目前仍很薄弱。因此，开展家蚕安全转基因技术体系开发对促进转基因家蚕产业化具有重要意义。针对蚕业只用家蚕日系原种×华系原种的杂交一代（F1）蚕种进行大面积生产，为防止转基因F1蚕种在推广应用过程中不可控的转基因扩散安全隐患，本项目拟开发一种实现转基因家蚕F1生殖细胞所有外源DNA自动删除的安全转基因技术体系。利用家蚕生殖腺特异性表达基因启动子调控GAL4蛋白在生殖细胞特异表达，进而激活FLP重组酶表达并完成转基因家蚕F1生殖细胞基因组中所有外源DNA序列的组织特异性删除，最终同时保证转基因安全和目的经济性状实现。该技术有望从根本上解决转基因F1蚕种安全生产的瓶颈，推动转基因家蚕产业化，并对其他昆虫安全转基因技术发展提供重要参考。

Transgenic technology is an important tool for gene function analysis and genetic improvement of the silkworm Bombyx mori. But the safety problems of transgenic silkworm have become the key problems that hindering the industrialization development of transgenic silkworm, and the present research on the safety problems of transgenic silkworm was also not in-depth. Therefore, development of the safety of transgenic technologies of silkworm are of great significance to promote the industrialization of transgenic silkworm. In the sericulture production, only the first filial generation (F1) of eggs from Japanese original strain × Chinese original strain was used for large-scale breeding of the silkworm. In order to eradicate the hidden trouble of uncontrolled transgene dispersal in the process of popularization and application of F1 transgenic silkworm eggs, this project intends to develop a safe transgenic technology for automatic elimination of all exogenous DNA from the germ cell genome of the F1 transgenic silkworms. We used the gonad-specific gene promoters to induce GAL4 protein expression in the germ cells of the F1 transgenic silkworms, then activating the expression of FLP recombinase and complete site-specific deleted of all exogenous DNA sequences in the germ cell genome of the F1 transgenic silkworms. This strategy could be used to ensure the safety of transgene and realization of the economic characters of target transgene at the same time. This technology is expected to solve the bottleneck of the safe production of F1 transgenic silkworm eggs fundamentally, and promote the industrialization of transgenic silkworm, as well as provide important reference for establishing the safety of transgenic technologies in other insect species.