Tetrodotoxin and paralytic shellfish toxins derived from RNA of marine bacteria

河豚毒素（TTX）和麻痹性贝类毒素（PSP）是具有相似药理活性的强效神经毒素。这两种毒素由不同的研究人员独立研究，因为它们是不同的毒素，具有不同的化学结构，分布在不同的生物体中。没有讨论它们之间的相关性。另一方面，我们报道了具有代表性的TTX携带动物河豚具有PSP和TTX，并且这两种毒素通过RNase消化从有毒河豚肝脏的高分子部分释放出来。这些事实表明，这两种毒素都与某些生物体的RNA相关。本研究发现，产鞭毛藻PSP的代表性植物tamarense Alexandrium既具有TTX，也具有PSP。最近在一些菌株中发现了TTX和PSP。这些细菌包括在海水中常见的一种细菌，这表明大多数海洋生物都暴露于这些细菌中。目前的研究表明，常见的水生生物都含有这两种毒素，尽管含量很低。据报道，细菌的毒素产量非常低。这一事实与普通动物体内毒素含量较低的情况完全吻合。然而，它不能解释这些毒素在特定动物如河豚中含量高的原因，这表明某些未知的机制使特定动物有毒，例如特定动物和细菌协同产生毒素的机制。在有毒河豚标本的肝脏中发现了共生细菌。经抗生素处理后，共生菌消失。这些标本的肝脏是无毒的，表明肝脏中的共生细菌参与了毒素的积累。虽然电镜观察未发现胞内细菌，但用抗细菌抗体对其中一个细胞器进行了染色。它也是。

Tetrodotoxin (TTX) and paralytic shellfish toxins (PSP) are potent neurotoxins with similar pharmacological activity. Both toxins have been studied by different researchers independently, because they are different toxins with different chemical structure which distribute in different organisms. No correlation between them has been discussed. On the other hand, we reported that puffer, a representative TTX-bearing animal, possesses PSP as well as TTX, and that both toxins are released from high molecular fraction of the liver of toxic puffer by RNase digestion. These facts suggest that both toxins occur correlatedly in association with RNA of some organism. The present study revealed that Alexandrium tamarense, a representative PSP producing dinoflagellate, possesses TTX as well as PSP.Recently, TTX and PSP have been identified in some bacterial strains. These bacteria include a species which can be commonly observed in the seawater, indicating that most of marine organisms are exposed to these bacteria. The present study showed that common aquatic organisms possess both toxins, thogh the level is very low. Toxin productibity of bacteria is reported to be very low. This fact coincides well with low level of toxin in common animals. Hawever, it could not explain the high amount of these toxins in specific animals such as puffer, suggesting that some unknown mechanism for the specific animals to be made toxic, for example, the toxin production mechanism by collaboration of the specific animals and bacteria. Symbiosis of bacteria was found in the liver of toxic puffer specimens. Symbiotic bacteria disappeared when the specimens were treated with antibiotics. The liver of these specimens belomes nontoxic, showing that symbiotic gacteria in the liver is involved in toxin accumulation. Although endocellular bacteria were not observed in A.tamarense by EM observation, one of the organella was stained by antibody against bacterium isolated from A.tamarense. It was also sta