Zmerli Triki Habiba, Laabir Mohamed, Moeller Peter, Chomérat Nicolas, Kéfi Daly-Yahia Ons
Tunisian National Agronomic Institute (INAT), U.R Marine Biology (FST El Manar I), IRESA - Carthage University, 43 Avenue Charles Nicolle, 1082 Tunis, Tunisia.
UMR 9190 MARBEC IRD-Ifremer-CNRS-Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France.
Toxicon. 2016 Mar 1;111:91-9. doi: 10.1016/j.toxicon.2015.12.018. Epub 2015 Dec 31.
The dinoflagellate Alexandrium pseudogonyaulax is widely distributed around the world including the Mediterranean waters. The objectives of this study were to determine the morphology and phylogenic affiliation of A. pseudogonyaulax strain isolated from Bizerte Lagoon (Mediterranean waters, Tunisia) and investigate its toxicity. Molecular analyses confirmed the morphological identification of the isolated strain (APBZ12) as A. pseudogonyaulax. Moreover, it showed that it is 100% identical with strains of this species found in New Zealand, Japan, China and North Sea (Norway and Denmark) suggesting that this species is cosmopolitan. Until now, no toxin studies have been conducted on fully characterized (morphologically and molecularly) A. pseudogonyaulax. Cellular toxin production was determined using high pressure liquid chromatography coupled to mass spectrometry (HPLC/MS). Results showed for the first time that A. pseudogonyaulax contains goniodomin A (GDA), a highly toxic macrolide polyether previously shown to be produced by two other dinoflagellate species Alexandrium monilatum (Hsia et al., 2006) and Alexandrium hiranoi (erroneously identified as A. pseudogonyaulax in Murakami et al., 1988) in American and Japanese waters, respectively. This biologically active toxin has been associated over decades with fish mortality. Our study showed that the cell extracts of APBZ12 showed an important bioactivity using GH4C1 rat pituitary cytotoxicity bioassay.
伪戈氏亚历山大藻这种甲藻在包括地中海海域在内的世界各地广泛分布。本研究的目的是确定从突尼斯比塞大泻湖（地中海海域）分离出的伪戈氏亚历山大藻菌株的形态和系统发育关系，并研究其毒性。分子分析证实了分离菌株（APBZ12）在形态上鉴定为伪戈氏亚历山大藻。此外，研究表明它与在新西兰、日本、中国以及北海（挪威和丹麦）发现的该物种菌株100%相同，这表明该物种具有世界性分布。到目前为止，尚未对已完全进行形态学和分子学特征鉴定的伪戈氏亚历山大藻开展毒素研究。利用高压液相色谱-质谱联用技术（HPLC/MS）测定细胞毒素产量。结果首次表明，伪戈氏亚历山大藻含有戈尼多明A（GDA），这是一种剧毒的大环内酯聚醚，此前分别在美国和日本海域发现另外两种甲藻——纤细亚历山大藻（Hsia等人，2006年）和平井亚历山大藻（在Murakami等人，1988年中被错误鉴定为伪戈氏亚历山大藻）能够产生这种物质。几十年来，这种生物活性毒素一直与鱼类死亡有关。我们的研究表明，使用GH4C1大鼠垂体细胞毒性生物测定法，APBZ12的细胞提取物显示出重要的生物活性。
