蓝藻基因表达载体系统的构建和应用

蓝藻是一类具植物型放氧光合作物特性的原核生物。多数蓝藻富含营养物质，无毒，是表达外源目的基因的独特受体系统。因此，构建适用于蓝藻表达外源目的基因的载体系统，并用于表达药物活性肽基因，已成为当前蓝藻基因工程研究的热点之一。本课题组10多年来率先在国内开展蓝藻基因工程研究，从蓝藻Plectonema botyanum中分离得到了约1.5kb的小质粒，以此为出发质粒，构建了蓝藻穿梭质粒pPRS-1和穿梭质粒表达载体pPKE2；同时根据DNA片段同源重组的性质，构建了蓝藻Calothrix sp.PCC7601、Synechococcus sp.PCC7942的基因整合平台系统。在国家863项目经费资助下，利用构建的蓝藻质粒载体和基因整合平台系统，把人源胸腺素基因转入蓝藻Calothrix sp.PCC7601和Synechoccus sp.PCC7942，并能高效表达，首次获得了可直接口服的含人源胸腺素的转基因蓝藻，这对研究和开发基因工程口服药物具有重大的科学意义和经济、社会效益。

Construction and Applioation of the Gene Expressing Vector for Cynaobactorium

Cyanobacteria (blue green) algae, show special characters in photosynthesis, nitrogen fixation, genetics and evolution. Because most of them are not virulent and have high nutritional value, this kind of special prokaryote can become a new host system for the expression of foreign genes. It had been one of the hottest study on the genetic engineering of cyanobacteria that construction expression vector and expression of specialmedical peptide in blue green algae. For more than ten years study on genetic engineering of cyanobacteria, our group had constructed a serial of shutter plasmids from a little endocellular plasmid pPbS of cyanobacteria Plectonema boryanum, and gene integration platform system for Synechococcus sp. PCC7942 and Calothrix sp. PCC7601. Funded by national high science and technical program(863),we had succeed in expression human thymosinαl gene in cyanobacteria Synechococcus sp. PCC7942 and Calothrix sp. PCC7601 by using these transform vector systems. The transgene blue green algae bring us a wonderful future on the genetic engineering medicine production, which has high value in both science and economic.