Pomati Francesco, Kellmann Ralf, Cavalieri Rosi, Burns Brendan P, Neilan Brett A
Cyanobacteria and Astrobiology Research Laboratory, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
Environ Int. 2006 Aug;32(6):743-8. doi: 10.1016/j.envint.2006.03.010. Epub 2006 May 2.
Blooms of the freshwater cyanobacterium Anabaena circinalis are recognised as an important health risk worldwide due to the production of a range of toxins such as saxitoxin (STX) and its derivatives, also known as paralytic shellfish poisoning (PSP) toxins. In this study the transcriptional profile of PSP toxin-producing and non-toxic strains of A. circinalis was investigated by means of a DNA microarray approach. Additionally, gene expression was studied after exposure of toxic A. circinalis cultures to lidocaine hydrochloride at 1 microM for 2 h. Under standard growth conditions, a limited number of putative toxic-strain distinctive DNA fragments, identified in previous studies, were preferentially expressed in toxic versus non-toxic strains. The same genes did not significantly change their expression after exposure to 1 microM lidocaine, conditions previously shown to induce STX production in the cyanobacterium Cylindrospermopsis raciborskii T3. Lidocaine supplementation, however, enhanced the transcription of genes involved in physiological adaptive responses and bloom formation in cyanobacteria, such as the gas vesicle structural protein A and phycocyanin. The heat shock protein HSP-70 and the chlorophyll-a binding protein isiA were significantly repressed by lidocaine exposure. Stress response proteins and genes implicated in secondary metabolism were repressed, including phosphopantetheinyl transferases. The BGGM1 DNA microarray, used in this study, was shown to be suitable for gene expression studies in cultured toxic cyanobacteria and allowed the analysis of gene transcripts associated with surface scum formation by toxic A. circinalis.
淡水蓝藻卷曲鱼腥藻水华因其产生多种毒素（如石房蛤毒素（STX）及其衍生物，也称为麻痹性贝类毒素（PSP））而被公认为是全球范围内的重大健康风险。在本研究中，通过DNA微阵列方法研究了产PSP毒素和无毒的卷曲鱼腥藻菌株的转录谱。此外，在将有毒的卷曲鱼腥藻培养物暴露于1 microM盐酸利多卡因2小时后，对基因表达进行了研究。在标准生长条件下，先前研究中鉴定出的有限数量的假定有毒菌株特异性DNA片段在有毒菌株与无毒菌株中优先表达。在暴露于1 microM利多卡因后，这些相同的基因并未显著改变其表达，而先前已证明该条件可诱导蓝藻类柱孢藻T3产生STX。然而，补充利多卡因可增强蓝藻中参与生理适应性反应和水华形成的基因的转录，如气荚膜结构蛋白A和藻蓝蛋白。热休克蛋白HSP - 70和叶绿素a结合蛋白isiA在利多卡因暴露后显著受到抑制。参与次级代谢的应激反应蛋白和基因也受到抑制，包括磷酸泛酰巯基乙胺基转移酶。本研究中使用的BGGM1 DNA微阵列被证明适用于培养的有毒蓝藻中的基因表达研究，并能够分析与有毒卷曲鱼腥藻形成表面浮沫相关的基因转录本。
