Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Cell Res. 2011 Jun;21(6):934-43. doi: 10.1038/cr.2011.36. Epub 2011 Mar 15.
Sericulture has been greatly advanced by applying hybrid breeding techniques to the domesticated silkworm, Bombyx mori, but has reached a plateau during the last decades. For the first time, we report improved silk yield in a GAL4/UAS transgenic silkworm. Overexpression of the Ras1(CA) oncogene specifically in the posterior silk gland improved fibroin production and silk yield by 60%, while increasing food consumption by only 20%. Ras activation by Ras1(CA) overexpression in the posterior silk gland enhanced phosphorylation levels of Ras downstream effector proteins, up-regulated fibroin mRNA levels, increased total DNA content, and stimulated endoreplication. Moreover, Ras1 activation increased cell and nuclei sizes, enriched subcellular organelles related to protein synthesis, and stimulated ribosome biogenesis for mRNA translation. We conclude that Ras1 activation increases cell size and protein synthesis in the posterior silk gland, leading to silk yield improvement.
家蚕通过杂交育种技术得到了极大的发展，但在过去几十年中已经达到了一个瓶颈。我们首次报道了通过 GAL4/UAS 转基因家蚕提高丝产量。在后丝腺中特异性过表达 Ras1(CA)致癌基因可将丝产量提高 60%，而仅将食物消耗量提高 20%。在后丝腺中 Ras1(CA)过表达激活 Ras，可增强 Ras 下游效应蛋白的磷酸化水平，上调丝素 mRNA 水平，增加总 DNA 含量，并刺激内复制。此外，Ras1 的激活增加了细胞和细胞核的大小，丰富了与蛋白质合成相关的亚细胞器官，并刺激核糖体生物合成以进行 mRNA 翻译。我们得出结论，Ras1 的激活增加了后部丝腺的细胞大小和蛋白质合成，从而提高了丝产量。
