Control silkworm sex to improve raw silk quality

Not long ago, Huang Yongping's research group of the Institute of Plant Physiology and Ecology of the Shanghai Institute of Life Sciences, Chinese Academy of Sciences successfully constructed a female-specific lethal silkworm transgenic system, which can improve the quality of silkworm and raw silk.

Bombyx mori is a representative model insect of Lepidoptera and it is also an important economic insect. Compared with the female silkworm, the male silkworm has a strong constitution and is easier to feed. At the same time, the silkworm has less mulberry mulberry and the leaf silk conversion rate is high; in addition, the male silk fineness and fineness are good, and it is suitable for brewing high-grade raw silk. Therefore, raising male silkworm exclusively is an important goal for sericulture production. In recent years, the continuous advancement of genetic manipulation techniques of silkworms, including genetically modified technologies, has provided new possibilities for breeding through molecular biology methods.

Huang Yongping teamed up with the British Oxitec company and the Sericulture Research Institute of Zhejiang Academy of Agricultural Sciences to use the tetracycline Tet-off regulatory system and the sex-specific selection of a double sex gene from a lepidopteran cotton pink bollworm Sex splicing mechanism, a silkworm transgenic system that specifically expresses transcriptional activator protein (tTAV) in female silkworm is constructed. In this system, the expression of the toxic protein tTAV as an effector factor is controlled by the tetracycline switch and the gender switch. If a certain amount of tetracycline is added to the feed, the expression of tTAV in the individual is inhibited by tetracycline, both female and male silkworms Normal development can occur; if tetracycline is not added to the diet, tATV accumulation in female individuals will result in embryonic or larval early mortality, whereas in male individuals, there is still no tTAV expression due to regulation by sex-specific alternative splicing mechanisms. Development is not affected, so as to achieve the purpose of raising male silkworm exclusively.

The use of genetic manipulation technology to directly genetically modify silkworms can lead to the development of new varieties in a short period of time and improve the quality of silkworms and even raw silk. At the same time, the results obtained in silkworm can also be applied to account for 70% to 80% of agricultural and forest pests. The genetic control of Lepidoptera pests. The project was funded by the National Natural Science Commission and the Ministry of Science and Technology.