中文摘要：

大规模基因组测序发现放线菌基因组内包含有极丰富的天然产物合成基因，是非常有价值的资源。放线菌基因组中负责天然产物合成的基因通常成簇存在。要想完整地克隆这些较大的基因簇并且进行功能研究，或者通过异源表达激活原本沉默的天然产物合成基因簇，需要大容量的载体系统和合适的异源宿主。本文重点介绍了放线菌中常用于基因组大片段克隆的载体及异源表达宿主改造的研究进展。

英文摘要：

Biosynthetic pathway genes for each natural product are mostly located together on a large and continuous segment of the genome to compose a gene cluster. Actinobacteria genomes usually contain various natural product biosynthetic gene clusters, which are valuable resources of potential applications in medicine, agriculture and industry. Some of these gene clusters are considered to be silent because no related metabolites could be detected under laboratory condi- tions. For functional analyses of natural product biosynthetic gene clusters, researchers con- structed a lot of high-capacity vectors and many heterologous hosts by genetic engineering for cloning and expressing large DNA fragments of actinobacteria genomes in the last two decades.