利用real-time RT-PCR研究大型蚤对铜绿微囊藻毒素合成基因转录水平影响

摘要

Recently the interactions between zooplankton and Microcystis species have been concerned.Some studies have revealed that zooplankton can induce the change of toxin production in Microcystis.Microcystins( mcys ) are cyclic heptapeptides, synthesized via a mixed polyketide synthase/nonribosomal petide synthetase system encoded by microcystin synthatase gene(ncy) operon, however no studies were conducted to elucidate the effect of zooplankton on the gene expressions of mcy genes.The present paper studied the effect of Daphnia upon the transcriptional regulation of genes responsible for microcystin synthesis in Microcystis aeruginosa PCC7806 using the real-time RT-PCR for the first time.Both mcyB and mcyD transcript levels increased under the grazing stress of Daphnia, and it is speculated that the increase of mcy gene clusters transcription was the induced defense of Microcystis aeruginosa PCC7806 against Daphnia stress.%近年来关于浮游动物与微囊藻相互作用的研究逐渐被关注.其中有的研究认为浮游动物能够诱导产毒细胞毒素含量的变化.微囊藻毒素是由微囊藻毒素合成基因编码翻译的,目前关于浮游动物对微囊藻毒素合成基因相对表达的影响并无报道,本文首次通过实时定量逆转录PCR方法研究铜绿微囊藻PCC7806产毒相关基因mcyB和mcyD在大型蚤胁迫下相对表达变化结果显示微囊藻mcyll,mcyD基因相对表达均有上调,表明铜绿微囊藻PCC7806通过上调产毒基因的转录水平达到对大型蚤的诱导防御,从而为浮游动物与微囊藻相互作用研究提供新的依据.