REPRODUCTION AND SEXUALITY IN PFIESTERIA SHUMWAYAE (DINOPHYCEAE) 1
REPRODUCTION AND SEXUALITY IN PFIESTERIA SHUMWAYAE (DINOPHYCEAE) 1
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DOI：
10.1046/j.1529-8817.2003.03057.x
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发表时间：
2003-08
影响因子：
2.9
通讯作者：
M. Parrow;J. Burkholder
中科院分区：
文献类型：
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作者：
M. Parrow;J. Burkholder
Shumwayae是一种广泛分布于温带亚热带河口沃茨的异养甲藻。在这项研究中，五个克隆分离物从北美东海岸，一个来自新西兰，和一个混合的复合克隆培养在水族馆和饲养活鱼。用光镜、扫描电镜和流式细胞术研究了鱼类的分裂、性行为和摄食。跟踪了从水族馆分离的生殖胞囊的发育过程。同时excysted鞭毛虫种群进行了检查的性，然后为摄食行为和繁殖时，给仔鱼。生殖囊大小不等，进行原生质体分裂，最常见的是产生2至8个双鞭毛后代。配子融合，产生的planozyotes，和核循环被记录为性的证据。配子从孢囊中出现，融合体大致为同花受精。产生的平合子有两个纵向鞭毛和一个横向鞭毛，显然在成囊前进食。在核分裂之前，在假定的合子包囊中发生了明显而漫长的染色体运动（核循环）。这些孢囊没有表现出休眠在不断增长的文化，并产生两个或四个双鞭毛后代。鞭毛细胞以淡水鱼组织为食，然后包囊繁殖。阶段表明一个完整的性周期（融合，planozyotes，和核循环）是罕见的或不存在的克隆文化，但在混合克隆文化相对丰富。自我不育因素显然影响性行为。饥饿的种群形成静止的包囊，当提供食物时释放游泳细胞。Shumwayae在繁殖和性行为方面与近缘种相似。
Pfiesteria shumwayae is a heterotrophic dinoflagellate with a widespread distribution in temperate‐subtropical estuarine waters. In this study, five clonal isolates from the eastern coast of North America, one from New Zealand, and a mixed composite of clones were cultured in aquaria and fed live fish. Division, sexuality, and phagotrophic feeding on fish were studied by LM, SEM, and flow cytometry. The development of reproductive cysts isolated from aquaria was followed. Synchronously excysted flagellate populations were examined for sexuality and then for feeding behavior and reproduction when given larval fish. Reproductive cysts varied in size and underwent protoplast division(s), most commonly producing two to eight biflagellated offspring. Fusing gametes, resulting planozygotes, and nuclear cyclosis were documented as evidence of sexuality. Gametes emerged from cysts, and fusions were approximately isogamous. Resulting planozygotes had two longitudinal flagella and one transverse flagellum and apparently fed before encysting. Distinct and lengthy chromosome movements (nuclear cyclosis) occurred in presumed zygotic cysts before nuclear division(s). These cysts did not exhibit dormancy in growing cultures and produced two or four biflagellated offspring. Flagellated cells fed on surficial fish tissues and then encysted for reproduction. Stages indicating a completed sexual cycle (fusion, planozygotes, and nuclear cyclosis) were uncommon or absent in clonal cultures but were relatively abundant in the mixed clone culture. Self‐sterility factors apparently influenced sexuality. Starved populations formed quiescent cysts that released swimming cells when food was provided. Pfiesteria shumwayae was similar in reproduction and sexuality to closely related species.