石蚕丝是水栖昆虫石蚕（Caddisfly)在水中作成的特殊天然蛋白纤维，具有多种优良的物理、生化等特性。但是因其来源稀少、采集困难等原因，限制了它的广泛应用。利用家蚕生物反应器，“让家蚕吐出石蚕丝”是解决上述问题的一条简便有效的途径。本项目拟通过我们已经建立的家蚕Fib-H敲除（HKO）系统，并利用过表达丝素基因关键转录调控因子Bmdimm的方法，促使石蚕丝重链基因（CFib-H）在家蚕丝腺中得以高效表达，以期开发一种转石蚕丝基因蚕丝纤维。项目将在构建HKO-(CFib-H) 和HKO-(CFib-H)-Bmdimm两种转石蚕CFib-H基因家蚕的基础上，研究CFib-H基因在的转录和表达水平，分析Bmdimm调控因子通过保幼激素（JH）通路对CFib-H基因的转录水平调控能力，调查转基因家蚕丝的理化性质。项目有望建立一种家蚕丝腺高效表达外源基因系统，并在此基础上创制一种新型蚕丝复合纤维。

Caddisfly silk is a unique natural protein fiber produced by the aquatic caddisfly. The silk has excellent physical and biochemical properties. Due to the limited sources of caddisfly and its difficulty in sampling, the direct collection of caddisfly silk from the silkworm is widely considered as the simplest and most effective alternative. The project aims to efficiently promoting the expression of caddisfly silk heavy-chain gene CFib-H in the silkworm and to developing a high-performance caddisfly silk gene fibers, based on our previously established Fib-H gene knock-out mutants(HKO) system, facilitated by the key factor Bmdimm. Two organism models of transgenic silkworms HKO-(CFib-H) and HKO-(CFib-H)-Bmdimm will be created in the project, in order to study the transcription and expression of CFib-H gene, to analyze Bmdimm’s transcriptional regulation of CFib-H gene via juvenile hormone (JH) pathway, and to investigate the physical and physiological properties of transgenic silk. This project is expected to establish an efficient caddisfly silk gene expression system in the silkworm gland.