Recently, the research findings of Professor Tan Anjiang's team from the School of Biotechnology, Jiangsu University of Science and Technology/Key Laboratory of Sericulture, Ministry of Agriculture and Rural Affairs, were published online in the international academic journal PNAS Nexus. The study achieved significant progress by constructing various silkworm silk gland expression systems, enabling the abundant expression of spider and bagworm silk proteins within silkworms. This advancement opens up new avenues for utilizing silkworms as bioreactors for customized silk protein production.
It is noted that besides silkworms, various animals such as spiders and bagworms can synthesize fiber proteins with excellent properties. These fiber protein materials have wide-ranging applications in fields like national defense, aerospace, and medicine, but large-scale production remains challenging.
The silkworm silk gland serves as an excellent protein expression system, and the development of gene editing technology provides new opportunities for efficiently producing novel silk materials using genetically transformed silkworms. This study constructed and comprehensively compared multiple genetic transformation systems, including the transposon-mediated transgenic heavy chain expression system (FibH-T), the transcription activator-like effector nuclease (TALEN)-mediated silk heavy chain replacement system (FibH-R), and the silk light chain fusion system (FibL-F).
In the FibH-R system, the content of spider dragline silk protein MaSp2 (160 kDa) and bagworm silk fibroin protein EvFibH (230 kDa) reached 51.02% and 63.77%, respectively, in the cocoon layers of homozygous transformed individuals. Furthermore, the presence of MaSp2 and EvFibH increased the toughness of the recombinant silkworm silk fibers by approximately 86% and 80%, respectively.
Structural analysis indicated that the presence of unique polyalanine motifs in the repeat sequences of MaSp2 and EvFibH increased the crystallinity of the recombinant fibers by approximately 40%, effectively enhancing the strength of the recombinant fibers. This study created several novel silkworm silk fiber germplasms, paving the way for large-scale production of novel fiber materials using silkworms and the expression of other high-value-added products.
The first and corresponding authors of this paper are affiliated with Jiangsu University of Science and Technology. The first author, Doctor Yu Ye, and the corresponding author, Professor Tan Anjiang, received significant support from the team of Professor Lin Zhi from Tianjin University during the experimental process, as well as financial support from projects such as the National Natural Science Foundation and the Natural Science Foundation of Jiangsu Province.
Link to the related paper: https://doi.org/10.1093/pnasnexus/pgae128
