P25 Gene Knockout Contributes to Human Epidermal Growth Factor Production in Transgenic Silkworms |
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Authors: | Meiyu Wu Jinghua Ruan Xiaogang Ye Shuo Zhao Xiaoli Tang Xiaoxiao Wang Huiping Li Boxiong Zhong |
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Affiliation: | College of Animal Science, Zhejiang University, Hangzhou 310058, China; (M.W.); (J.R.); (X.Y.); (S.Z.); (X.T.); (X.W.); (H.L.) |
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Abstract: | Transgenic silkworm expression systems have been applied for producing various recombinant proteins. Knocking out or downregulating an endogenous silk protein is considered a viable strategy for improving the ability of transgenic expression systems to produce exogenous proteins. Here, we report the expression of human epidermal growth factor (hEGF) in a P25 gene knockout silkworm. The hEGF gene regulated by the P25 gene promoter was integrated into a silkworm’s genome. Five transgenic positive silkworm lineages were generated with different insertion sites on silkworm chromosomes and the ability to synthesize and secrete proteins into cocoons. Then, a cross-strategy was used to produce transgenic silkworms with a P25 gene knockout background. The results of the protein analysis showed that the loss of an endogenous P25 protein can increase the hEGF production to about 2.2-fold more than normal silkworms. Compared to those of transgenic silkworms with wild type (non-knockout) background, the morphology and secondary structure of cocoon silks were barely changed in transgenic silkworms with a P25 gene knockout background, indicating their similar physical properties of cocoon silks. In conclusion, P25 gene knockout silkworms may become an efficient bioreactor for the production of exogenous proteins and a promising tool for producing various protein-containing silk biomaterials. |
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Keywords: | transgenic silkworm transgene P25 gene knockout human epidermal growth factor |
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