I studied the flagellar movements and mating behavior of biflagellate gametes produced by the green marine macroalga Bryopsis maxima using high-speed video microscopy. This procedure allowed me to visualize the very rapid fertilization process in a marine ulvophycean. Discharged male and female gametes always swung their flagella backwards during forward swimming. They swam with a flagellar beat type pattern in which undulatory waves produced at the flagellar bases propagated towards the tips. Each beat cycle lasted 15–20 ms. Male gametes were immediately attracted to the vicinity of female gametes when the two mating types were mixed. As each male gamete swam past a female, it reversed direction towards the female by changing the beat pattern of one of its two flagella. The attraction of male gametes to the female ones was inhibited in calcium-free seawater in both the presence and absence of 10 mM ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid, a calcium chelator, but attraction recovered in the presence of 10 mM CaCl₂, suggesting that Ca²⁺ is necessary for the attraction response. The initial contact between the two gametes occurred when one of the male flagellar tips encountered a female flagellum. The male gamete kept in contact with the female gamete (i) at the flagellar tips, and then (ii) by anterior cell body contact. Flagella continued to beat and cell bodies oscillated as gametes maintained contact. In the final step, the gametes fused.

中文翻译：

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海洋绿色大型藻类 Bryopsis maxima (Ulvophyceae, Chlorophyta) 受精过程中雄配子的鞭毛跳动模式

我研究了绿色海洋大型藻类Bryopsis maxima产生的双鞭毛配子的鞭毛运动和交配行为使用高速视频显微镜。这个过程让我能够看到海洋藻类中非常快速的受精过程。在向前游泳时，排出的雄性和雌性配子总是向后摆动鞭毛。它们以鞭毛节拍型模式游泳，其中鞭毛基部产生的波动波向尖端传播。每个节拍周期持续 15-20 毫秒。当两种交配类型混合时，雄配子立即被吸引到雌配子附近。当每个雄配子游过雌配子时，它会通过改变其两个鞭毛之一的节拍模式，将方向转向雌性。在存在和不存在 10 mM 乙二醇-双（β-氨基乙基醚）-的情况下，无钙海水中雄配子对雌配子的吸引力均受到抑制N , N , N ', N '-四乙酸，一种钙螯合剂，但在 10 mM CaCl ₂存在下吸引力恢复，表明 Ca ²⁺是吸引反应所必需的。两个配子之间的初始接触发生在其中一个雄性鞭毛尖端遇到雌性鞭毛时。雄配子与雌配子保持接触 (i) 在鞭毛尖端，然后 (ii) 通过前细胞体接触。随着配子保持接触，鞭毛继续跳动并且细胞体振荡。在最后一步，配子融合。