Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400715, China.
Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400715, China.
Int J Biol Macromol. 2023 May 15;237:124182. doi: 10.1016/j.ijbiomac.2023.124182. Epub 2023 Mar 25.
The silk gland of silkworm is a unique organ in which silk proteins are synthesized, secreted, and transformed into fibers. The anterior silk gland (ASG) is located at the end of the silk gland, and is thought to be involved in silk fibrosis. In our previous study, a cuticle protein, ASSCP2, was identified. This protein is specifically and highly expressed in the ASG. In this work, the transcriptional regulation mechanism of ASSCP2 gene was studied by a transgenic route. The ASSCP2 promoter was analyzed, truncated sequentially, and used to initiate the expression of EGFP gene in silkworm larvae. After egg injection, seven transgenic silkworm lines were isolated. Molecular analysis revealed that the green fluorescent signal could not be detected when the promoter was truncated to -257 bp, suggesting that the -357 to -257 sequence is the key region responsible for the transcriptional regulation of the ASSCP2 gene. Furthermore, an ASG specific transcription factor Sox-2 was identified. EMSA assays showed that Sox-2 binds with the -357 to -257 sequence, and thus regulates the tissue-specific expression of ASSCP2. This study on the transcriptional regulation of ASSCP2 gene provides theoretical and experimental basis for further studies of the regulatory mechanism of tissue-specific genes.
家蚕丝腺是一个独特的器官，其中合成、分泌和转化为纤维的丝蛋白。前部丝腺（ASG）位于丝腺的末端，被认为参与丝纤维的形成。在我们之前的研究中，鉴定了一个表皮蛋白 ASSCP2。这种蛋白在 ASG 中特异性高度表达。在这项工作中，通过转基因途径研究了 ASSCP2 基因的转录调控机制。分析了 ASSCP2 启动子，依次进行截断，并用于在蚕幼虫中启动 EGFP 基因的表达。通过卵注射后，分离出了七个转基因家蚕品系。分子分析表明，当启动子截断至-257bp 时，无法检测到绿色荧光信号，这表明-357 至-257 序列是 ASSCP2 基因转录调控的关键区域。此外，还鉴定了一个 ASG 特异性转录因子 Sox-2。EMSA 实验表明 Sox-2 与-357 至-257 序列结合，从而调节 ASSCP2 的组织特异性表达。这项关于 ASSCP2 基因转录调控的研究为进一步研究组织特异性基因的调控机制提供了理论和实验基础。
