Life history and morphology of Ichthyophonus hoferi in vitro
Life history and morphology of Ichthyophonus hoferi in vitro
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霍氏鱼的体外生活史和形态
DOI：
10.3147/jsfp.20.273
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
T. Sano
中科院分区：
文献类型：
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作者：
N. Okamoto;K. Nakase;H. Suzuki;Y. Nakai;Kyoji Fujii;T. Sano
本文描述了在不同培养条件下观察到的不同发育形态的霍费鱼，包括变形母细胞、阿米巴形体、类原质体、球形单核或双核体、厚壁球形多核体和球形多核菌丝终端体。将厚壁球形多核体接种于含10%胎牛血清的MEM中，在pH值为7~9的条件下，萌发后有少量菌丝生长，产生单核或双核球形小体，随后发育为厚壁球形多核体。在相同的MEM培养基中，在pH值为3~5的条件下，菌丝生长旺盛，菌丝顶端形成球形多核菌丝终端体。这些菌丝体的细胞壁厚度不同于原来的球形多核体。但在低pH条件下，在pH值为3或5时产生的球形多核菌丝终端体可以萌发形成更多的菌丝，而在pH为3的高pH条件下产生的菌丝终端体不产生菌丝，而只形成类原质样和椭圆形的阿米巴体。将球状多核菌丝终体接种于pH为7的TGC培养基中，其生长特征是菌丝生长粗大(15-20μm)，菌丝生长旺盛，形成与pH值为5时相同的球状多核菌丝终体。我们的观察表明，菌丝生长的范围和类型以及产生的球形菌体的大小和结构等差异反映了可用养分和菌丝生长的物理条件(如周围的pH)。在养殖中产生的厚壁球形多核体很可能与在受感染的鱼中观察到的厚壁形式相同，以前有许多不同的名称，如“休眠孢子”、“潜伏孢囊”和“大多核体”。
The varied developmental forms of Ichthyophonus hoferi induced in culture including amoeboblasts, amoeboid bodies, plasmodium-like bodies, spherical uni-or binucleate bodies, thick walled spherical multinucleate bodies and spherical multinucleate hyphal terminal bodies that were observed under different cultural conditions are described. When the thick walled spherical multinucleate bodies were seeded into MEM containing 10% fetal bovine serum at pH 7-9, there was minimal hyphal growth following germination, which produced spherical uni-or binucleate bodies subsequently developing into the thick walled spherical multinucleate bodies. At pH 3-5 in the same MEM medium the growth was characterized by abundant hyphal growth and the formation of spherical multinucleate hyphal terminal bodies at the tips of each hypha. These hyphal bodies differed from the original spherical multinucleate bodies in cell wall thickness. However, the spherical multinucleate hyphal terminal bodies produced at pH 3 or 5 could germinate to form more hyphae at these low pH levels but those produced at pH 3 when shifted to a higher pH of 7-9 did not produce hyphae but only formed the plasmodium-like and oval amoeboid bodies. When the spherical multinucleate hyphal terminal bodies were seeded into TGC medium at pH 7, the growth was characterized by production of a thick (15-20μm) and abundant hyphal growth on which were produced identical spherical multinucleate hyphal terminal bodies which had subsequent growth characteristics as those produced in MEM at pH 5. Our observations shows that differences such as the extent and type of hyphal growth and the size and structure of spherical bodies produced reflect the available nutrients and physical conditions such as pH surrounding I. hoferi. The thick walled spherical multinucleate bodies produced in culture is probably identical to the thick walled forms observed in infected fish and described previously by a number of different names such as “resting spore”, “latent cyst”, and “large multinucleate bodies”.