The group of TAN Anjiang at the CAS Institute of Plant and Plant Science has used gene-site replacement to express spider silk proteins in silk gland and silkworm pupa. The sgroup used TALEN technology to completely knock out the fibroin heavy chain (FibH) coding region and integrated a DNA fragment containing part of the spider silk gene. The expression of spider silk protein was up to 35.2%, much higher copared to reported transgenic methods (0.3-3%). Since the transferred spider silk protein fragment has a small molecular weight (about 70 kDa), the chimeric spider silk obtained this time has a decrease in strength compared with the control silk, but has a remarkable improvement in ductility.
CAS news release, August 8, 2918