丝素重链基因（Fib-H）的表达在转录水平受到调控，是研究真核生物基因转录调控的理想模型。我们发现，在家蚕5龄后期，FMBP-1和Fib-H的表达正相关。FMBP-1、SGF-1和SGF-3都定位于家蚕后部丝腺细胞核，它们可以与Fib-H基因中相邻的调控序列结合。研究表明在体外，FMBP-1可以与SGF-1和SGF-3结合。据此，我们推测FMBP-1与SGF-1和SGF-3可能在后部丝腺细胞核相互作用，协同调控Fib-H转录。FMBP-1还存在于后部丝腺细胞质中。推测激素信号通路可能调控FMBP-1的转录和入核，从而影响Fib-H表达。本项目将应用多种方法研究激素信号通路对FMBP-1的调控机制，并阐明FMBP-1与SGF-1和SGF-3相互作用的分子机制及其协同调控Fib-H转录的分子机制。本研究不仅可以为其他真核生物基因转录调控提供理论参考，而且对于提高蚕丝蛋白产量也有一定的指导意义。

The expression of fibroin heavy chain (Fib-H) is regulated at transcriptional level, which is an ideal model for the research of eukaryotic gene transcriptional regulation. We found that in the late fifth instar of silkworm, the expression of FMBP-1 was positively related to that of Fib-H. FMBP-1, SGF-1 and SGF-3 were found to be located in the nucleus of the posterior silk gland. They were able to bind with the adjacent regulatory sequences in Fib-H gene. Our studies showed that in vitro, FMBP-1 could bind with SGF-1 and SGF-3, respectively. Accordingly, we speculate FMBP-1 may interact with SGF-1 and SGF-3 in the nucleus of the posterior silk gland to regulate the transcription of Fib-H cooperatively. FMBP-1 was also present in the cytoplasm of the posterior silk gland. We speculated that the hormone signaling pathway may regulate the transcription of FMBP-1 and the entrance into the nucleus, thus affecting the expression of Fib-H. In this project, we will apply a variety of methods to study the regulatory mechanism of hormone signaling pathway on FMBP-1 and illustrate the molecular mechanism of the interactions between FMBP-1 and SGF-1 and SGF-3 and the collaborative regulation on the transcription of Fib-H. Our study is not only able to provide some theoretical references for other eukaryotic gene transcription regulation, but also to be used to improve the yield of silk protein possibly.