Environmental and Physiological Regulation of Toxicity in Dinoflagellates

有毒的鞭毛藻在世界各地的沿海水域零星繁殖，经常引起麻痹性贝类中毒（PSP）的爆发。这些水华的周期性经济和公共卫生影响范围从人类疾病和死亡到贝类资源的广泛检疫。虽然PSP毒素的化学结构和药理活性已经被很好地了解，但它们在鞭毛藻中的代谢作用仍然未知，导致来自不同地区的分离物或在不同生长条件下的一个分离物毒性变化的因素也是未知的。在亚历山大属（原Gonyanulax）物种的区域种群的背景下，安德森博士将继续在四个一般研究领域进行调查。具体来说，他将研究：a)毒素产生的动力学，主要强调我们现在假设的毒素产生与鞭毛细胞周期之间的联系；B)毒素产生的生理学，通过研究细胞中游离精氨酸浓度升高的原因和影响，以及鉴定参与毒素合成的蛋白质；C)通过超微结构水平的免疫细胞化学研究毒素的定位和功能，以及从鞭毛鞭毛虫细胞核中纯化和表征蛤蚌毒素结合复合物的努力；d)通过交配研究进行种群比较，并开发分子方法来区分亚历山大菌的近缘分离株。

Toxic dinoflagellates bloom sporadically in coastal waters throughout the world, often causing outbreaks of paralytic shellfish poisoning (PSP). The recurrent economic and public health impacts of these blooms range from human illness and death to extensive quarantine of shellfish resources. Although the chemical structure and pharmacological activity of the PSP toxins are well understood, their metabolic role within the dinoflagellate remains unknown, as are the factors that cause variability in toxicity between isolates from different regions or in one isolate under different growth conditions. Within the context of a regional population of Alexandrium (formerly Gonyanulax) species, Dr. Anderson will continue investigations in four general research areas. Specifically, he will examine: a) the dynamics of toxin production with major emphasis on the link we are now hypothesizing between toxin production and the dinoflagellate cell cycle; b) the physiology of toxin production, through studies on the causes and effects of elevated free arginine concentrations in the cell and identification of proteins involved in toxin synthesis; c) toxin localization and function through immunocytochemical studies at the ultrastructural level and efforts to purify and characterize a saxitoxin-binding complex from the dinoflagellate nucleus; and d) population comparisons through mating studies and development of molecular methods to discriminate between closely-related isolates of Alexandrium.