Ultrastructure and ontogeny of eyespots in dinoflagellates : an approach from the perspective of their endosymbiotic origins.

从太平洋沿岸的不同地点收集了许多鞭毛藻，包括柱头和散光种，随后建立了无性系培养。其中发现一属一种，命名为Amphidiniella sedentaria Horiguchi gen.et sp.nov。此外，还报道了一种具有新型眼斑的新鞭毛藻裸子藻（Gymnodinium natalense Horiguchi et Pienaar sp.nov.），并对其超微结构和眼斑发生进行了详细的研究。本研究发现四种鞭毛藻中含有一种色菌内共生藻，使这种鞭毛藻的总数达到六种。这6种具有内共生类型相似、眼斑类型（B型眼斑）相同的特点，这是整个鞭毛类中只有这6种才发现的。对这些物种眼斑的超微结构进行了研究。虽然这6种在形态上有很大的差异，但基于上述共同特征，我们认为这6种属于单一种。由于对鞭毛类动物眼斑的发生机制知之甚少，本文从显微镜下对B型眼斑的发生机制进行了研究。发现复制过程是眼斑分裂和新生形成的混合过程。B型眼斑中是否存在细胞器dna尚未得到证实。

Many dinoflagellates, both stigmatic and astigmatic species, were collected from various localities along the Pacific coast and subsequently clonal cultures were established. One of them was found to be a new genus and a species of honyaulacoid dinoflagellates and was described as Amphidiniella sedentaria Horiguchi gen.et sp.nov. Furthermore, a new dinoflagellate, Gymnodinium natalense Horiguchi et Pienaar sp.nov.which possesses a novel type of eyespot was slso described and its ultrastructure and ontogeny of the eyespot was studied in detail.Four species of dinoflagellates were found to contain a chromophyte endosymbiotic alga in this study and these findings made the total number of such dinoflagellates six. These six species share the characteristics, such as similar type of endosymbiont and same type of eyespot (Type B eyespot) which has been found only in these six species among entire dinoflagellates. The ultrastructure of the eyespot of these species was studied. Although these six species are morphologically quite defferent, based on above mentioned shared characteristics, the monophily of these six species was proposed.Since little has been known regarding the ontogeny of eyespot in dinoflagellates, the ontogeny of Type B eyespot was investigated hight microscopically. It was found that the duplication process was mixture of eyespot devision and de novo formation. The presence of organella-DNA in the Type B eyespot was not confirmed.