饲料中维生素和无机盐对rBmNPV-Bm表达系统植酸酶基因表达活性的影响

【目的】为查明宿主的营养对重组家蚕杆状病毒-家蚕表达系统(rBmNPV-Bm)外源基因表达活性的影响,探寻提高家蚕Bombyx mori生物反应器产率的新途径。【方法】以家蚕BmNPV病毒为表达载体,以人工饲料饲养的5龄家蚕为宿主,以植酸酶基因为报告基因,探讨了家蚕人工饲料中维生素和无机盐对外源基因表达产物活性的影响。【结果】家蚕血淋巴中外源植酸酶的活性随着饲料中维生素和无机盐添加量的不同而发生显著变化。在本试验设区范围内,当维生素C的含量为饲料干物质量的1 %,B族维生素混合物为0.25 %,无机盐混合物为1 %,维生素B6为100 g饲料干物中含2 mg时,血淋巴中植酸酶活性达到最大值。【结论】通过改变家蚕饲料中微量营养成分的含量是提高rBmNPV-Bm表达系统外源基因表达活性的有效途径。

Effects of vitamins and inorganic salt in artificial diet on the expression of phytase gene in rBmNPV-Bm expression system

[Aim] Enhancing the yield of silkworm bioreactor and disclosing the relation between the host nutritive condition and the expression of foreign gene in rBmNPV-Bm system. [Methods] The effects of vitamins and inorganic salt in artificial diet for the host insect of baculovirus, silkworm Bombyx mori, on the activity of foreign gene products was studied using BmNPV as an expression vector and phytase as a reporter gene. [Results] The activity of phytase in silkworm haemolymph varied remarkably with the amount of added vitamin and inorganic salt. The phytase activity in silkworm haemolymph reached the maximum when the amount of vitamin C was 1% of the dry weight of artificial diet, vitamin B mixture 0.25%, inorganic salts mixture 1% and the amount of vitamin B_6 is 2 mg per 100 g dry matter weight, respectively in the designed test scope. [Conclusions] The expression of phytase gene in BmNPV-Bm expression system could be enhanced efficiently by altering the levels of micronutrients available in the artificial diet for silkworm larvae.