Silkworms transformed with chimeric silkworm/spider silk genes spin composite silk fibers with improved mechanical properties

1. Florence Teulé^a,¹,², 
2. Yun-Gen Miao^b,¹, 
3. Bong-Hee Sohn^c,
4. Young-Soo Kim^c, 
5. J. Joe Hull^a,³, 
6. Malcolm J. Fraser, Jr^c,
7. Randolph V. Lewis^a,⁴, and 
8. Donald L. Jarvis^a,⁵

+Author Affiliations

Published online before print January 3, 2012, doi:10.1073/pnas.1109420109PNAS January 3, 2012

1. ^aDepartment of Molecular Biology, University of Wyoming, Laramie, WY 82071;
2. ^bCollege of Animal Sciences, Zhejiang University, Hangzhou 310029, People's Republic of China; and
3. ^cEck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556

1. Edited by David A. Tirrell, California Institute of Technology, Pasadena, CA, and approved November 28, 2011 (received for review June 10, 2011)

Abstract

The development of a spider silk-manufacturing process is of great interest. However, there are serious problems with natural manufacturing through spider farming, and standard recombinant protein production platforms have provided limited progress due to their inability to assemble spider silk proteins into fibers. Thus, we used piggyBac vectors 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.