ARS | Publication request: Silkworms transformed with chimeric silkworm/spider silk genes spin composite silk fibers with improved mechanical properties

Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 28, 2011
Publication Date: January 17, 2012
Citation: Florence, T., Yun-Gen, M., Bong-Hee, S., Young-Soo, K., Hull, J.J., Fraser, M.J., Lewis, R.V., Jarvis, D.L. 2012. Silkworms transformed with chimeric silkworm/spider silk genes spin composite silk fibers with improved mechanical properties. Proceedings of the National Academy of Sciences. 109(3):923-928.

Interpretive Summary: Silk fibers hold great potential as biomaterials for a number of applications. While silkworms are the current biological source of many silks, spider silk fibers have superior mechanical properties that are ideal for a number of medically relevant procedures. Spider farming for silk, however, is not viable. Thus, there is great interest in developing an inexpensive, convenient, and reliable biotechnological approaches to manufacture spider silk fibers as biomaterials. To accomplish this, transgenic silkworms were engineered to express a synthetic spider silk gene to produce composite silk fibers consisting in part of the synthetic spider silk protein. These composite fibers have improved mechanical properties, relative to the fibers produced by the parental animals.

Technical Abstract: The development of a spider silk manufacturing process is of great interest. piggyBac vectors were used to create transgenic silkworms encoding chimeric silkworm/spider silk proteins. The silk fibers produced by these animals were composite materials that included chimeric silkworm/spider silk proteins integrated in an extremely stable manner. Furthermore, these composite fibers were, on average, tougher than the parental silkworm silk fibers and as tough as native dragline spider silk fibers. These results demonstrate that silkworms can be engineered to manufacture composite silk fibers containing stably integrated spider silk protein sequences, which significantly improve the overall mechanical properties of the parental silkworm silk fibers.