Studies on the ancient type of swimming and flagellar beat pattern in green algae through High-speed Video analysis.

一般认为绿色单体鞭毛的搏动模式与纤毛相同，即绿色单体通过向前游动使细胞迟钝，并以蛙泳的方式搏动其前方的鞭毛。然而，我们知道，一些海洋分类群通过向后游泳来推动细胞，鞭毛在后面拍打。采用高速视频（Nac HMS 200、200帧/秒）观察了Pterosperma、Pyramimonas和Prasinovapilla (nomd . nud.) 3属3种的鞭毛搏动模式，并通过透射电镜观察了鞭毛器官的超微结构。根据形态学检查，这些属可归为单系分类群，即盐藻科。然而，在这些属中，鞭毛运动有许多不同之处，例如：翼鱼游泳非常向后游泳。本种鞭毛运动的特点是；1)运动类似于鞭毛的运动，表现出相同的模式重复…更多，即没有有效和恢复的击打迹象，2)鞭毛朝同一方向拍打，3)拍打是同步的；锥体单胞菌靠向前游泳。其鞭毛运动的特点是：1)纤毛运动包括有效和恢复的冲程；2)搏动发生在四个径向上；3)相对鞭毛的搏动周期是同步的；Prasinopapilla是翼虫和锥体单胞菌的中间产物。向前游动，鞭毛沿径向跳动；鞭毛的跳动是同步的，它们的运动是鞭毛的，而不是纤毛的。细胞结构也介于翼虫和锥体单胞菌之间。这些观察结果表明，在这些绿色单体的进化过程中，可能发生了以下进化变化：1)从向后游泳到向前游泳，2)从鞭毛到纤毛的拍打模式，3)从同步运动到非同步运动，4)从单向拍打到径向拍打。少

Flagellar beat pattern in green monads is generally believed to be the same as cilia, i.e. green monads Dull the cell by forward swimming, beating their flagella ahead of them with breastroke. However, it is known that some marine taxa push the cell by backwards swimming, beating their flagella behind. The flagellar beat pattern of three species of three genera, Pterosperma, Pyramimonas and Prasinovapilla (nom. nud.) were examined with a high speed Video (Nac HMS 200, 200 frames per second) and their flagellar apparatus ultrastructure examined by transmission electron microscopy. These genera can be assigned, based on morphological examinations, into a monophyletic taxon, the Halosphaeraceae. However, in these genera, there are many differences in flagellar movement, such as the following: Pterosperma swims vy backwards swimming. Characteristics of the flagellar movement in this species are; 1) the movement is similar to that of flagellar movement showing a repetition of the same patte … More rn, i.e. there is no sign of effective and recovery strokes, 2) the flagell beat in the same direction, 3) the beat is synchronous; Pyramimonas swims by forward swimming. Characteristics of its flagellar movement are, 1) ciliary movement comprising of effective and recovery strokes, 2) the beat occurs in four radial directions, 3)the beat cycle of opposed flagella is synchronous; Prasinopapilla can be assigned as an intermediate of Pterosperma and Pyramimonas. It swims by forward swimming, with flagella beating in radial directions; the flagella beat is synchronous and their movement is of the flagellum, not cilium. The cell structure is also intermediate between Pterosperma and Pyramimonas.These observations show that in the evolution of these green monads, the following evolutionary changes may have occurred: 1)from backward swimming to forward swimming, 2) from flagellar to ciliary beat pattern, 3) from synchronized to unsynchronized movement, 4) from uni- to radial-directional beating. Less