Preliminary studies of structure and function of the haptonema.

触丝体是一种独特的细胞器，仅在Prymnesiophyceae（=Haptophyceae）中发现。这种细胞器的超微结构、功能作用和生物学意义尚不清楚。本研究的目的是建立在结构和功能方面的触丝体的基本知识。选择Chrysochromulina来实现该项目。结果表明：毛金藻（Chrysochromulina hirta）是一种在食物捕获中起重要作用的触丝体。通过对平尾轮虫摄食过程的视频分析发现：捕食颗粒在附着丝上附着并向基部移动，聚集在颗粒聚集中心，形成紧密堆积的聚集体，聚集体向上移动至附着丝顶端，附着丝弯曲成S形，将聚集体输送至食泡。基于这些观察，它的结论是混合营养的Chrysochromulina hirta是通过整合的各种属性，包括表面粘附，表面运动，分泌的水泥材料和弯曲，这是明显的调控时间顺序。触丝体是由单线态微管组成，微管呈弧形或圆形排列，周围环绕着触丝体内质网，它们呈不对称排列，相对于细胞核、食物泡和鞭毛器等其他细胞成分具有单一的绝对构型。触丝弯曲和卷曲的方向是根据它的弯曲和卷曲的方向来精确确定的。

The haptonema is a unique cellular organelle known only in the Prymnesiophyceae(=Haptophyceae). Ultrastructue, functional roles and biological significance of this organelle is not well understood. The aim of this study was to establish basic knowledge on the haptonema of both structural and functional aspects. Chrysochromulina was choosen to achieve the project. The following results and conclusions were obtained.Chrysochromulina hirta, the haptonema plays an important role in food capture. Analysis of video-recorded food capturing and phagotrophic processes in C.hirata revealed that : Prey particles adhere and move on the haptonema towards the base ; They are accumulated at a point called particle aggregating center and transformed into tightly packed aggregate ; The aggregate is moved up to the tip of the haptonema ; The haptonema then bends in S-shape, resulting in delivery of the aggregate to the food vacuole. Based on these observations, it is concluded mixotrophy of Chrysochromulina hirta is achieved by integration of various properties of the haptonema including surface adhesion, surface motility, secretion of cement material and bending, which are obviously regulated in chronological order. The haptonema is composed of singlet microtubules arranged in an arc or a circle surronded by haptonemal ER.There components are arranged in asymmetrical fashion and has a single absolute configuration in relation to other cellular components such as the nucleus, food vacuole and the flagellar apparatus. The direction of haptonemal bending and coiling is precisely defined in reltion to its and*