家蚕丝腺中FMBP-1基因的转录水平及RNAi分析

Transcriptional levels and RNAi analysis of FMBP-1 gene in silk gland of Bombyx mori

家蚕丝腺是一个庞大的蛋白质资源库,丝腺细胞能够高效合成蚕丝蛋白,而蚕丝蛋白合成过程是极其复杂的调控系统,其中丝腺特异性转录因子起着非常重要的作用.FMBP-1是家蚕体内一种重要的丝腺特异性转录调节因子,分析该基因对蚕丝蛋白合成的作用,有利于探究蚕丝蛋白合成的机理,完善蚕丝蛋白表达调控的分子机制.本研究以不同丝量家蚕品种菁松、皓月、大造和镇江野桑蚕为供试材料,采用实时荧光定量PCR和RNAi技术检测分析了五龄家蚕丝腺中FMBP-1基因的转录水平以及FMBP-1基因对丝蛋白表达的影响,结果表明:在家蚕多丝量品种的丝腺中FMBP-1基因的表达量显著高于低丝量品种;五龄4 d家蚕喂食保幼激素后,家蚕丝腺内FMBP-1基因的表达量显著高于对照组;经RNAi处理后,家蚕蛹稍小、茧层率降低、蛾腹部皱缩,且丝腺中丝蛋白基因的表达水平也显著降低.研究结果提示:家蚕丝腺特异性转录因子FMBP-1在蚕丝蛋白的合成过程中作为正调节因子,发挥着重要的作用.

The silk gland of Bombyx mori is a huge protein resource bank,in which silk protein can be synthesised.Silk protein synthesis is a very complex regulatory system,in which silk gland specific transcription factors play a very important role.FMBP-1 is an important silk gland-specific transcription regulator in silkworm.Analyzing the effect of FMBP-1 on silk protein synthesis is helpful in exploring the mechanism of silk protein synthesis and improving the molecular mechanism of silk protein expression regulation.In this study,silkworm,wild mulberry silkworm and silkworm varieties with different silk weights were used as test materials.The transcription level of FMBP-1 gene in silk gland of fifth instar silkworm and the effect of FMBP-1 gene on silk protein expression were analyzed by real-time fluorescence quantitative PCR and RNAi.The results showed that the expression level of FMBP-1 gene in silk gland of silkworm varieties with multiple silk weights was significantly higher than that of silk varieties with low silk weights.After feeding juvenile hormone in the 4th day of fifth instar,the expression level of FMBP-1 gene in silk gland of silkworm was significantly higher than that of control group;after treatment with RNAi,silkworm pupae was slightly smaller,cocoon layer rate decreased,moth abdomen shrunk,and the expression level of silk protein gene in silk gland was also significantly lower.The results suggest that FMBP-1 plays an important role as a positive regulator in the synthesis of silk protein.