Ohmuro Junko, Ishijima Sumio
CREST, Japan Science and Technology, Kawaguchi, Saitama, Japan.
Mol Reprod Dev. 2006 Nov;73(11):1412-21. doi: 10.1002/mrd.20521.
Flagellar beating of hyperactivated golden hamster spermatozoa was analyzed in detail using digital image analysis and was compared to that of nonhyperactivated (activated) spermatozoa in order to understand the change in flagellar beating during hyperactivation and the active microtubule sliding that brought about the change in flagellar beating. Hyperactivated flagellar beating, which was characterized by a sharp bend in the proximal midpiece and low beat frequency, was able to alter the waveform with little change in beat frequency (constant-frequency beating), whereas activated flagellar beating, which was characterized by a slight bend in the proximal midpiece and high beat frequency, was able to alter beat frequency with little change in the waveform (constant-curvature beating). These results demonstrate that flagellar beating of hyperactivated and activated spermatozoa were essentially different modes and that hyperactivation was the mode conversion from constant-curvature beating to constant-frequency beating. Detailed analysis of flagellar bends revealed that the increase in curvature in the proximal midpiece during hyperactivation was due to the increase in total length of microtubule sliding in a nearly straight region between bends, while the rate of microtubule sliding remained almost constant.
利用数字图像分析详细分析了超活化金黄地鼠精子的鞭毛摆动，并将其与未超活化（活化）精子的鞭毛摆动进行比较，以了解超活化过程中鞭毛摆动的变化以及导致鞭毛摆动变化的活性微管滑动。超活化鞭毛摆动的特征是近端中段急剧弯曲且摆动频率低，能够在摆动频率变化不大的情况下改变波形（恒频摆动），而活化鞭毛摆动的特征是近端中段轻微弯曲且摆动频率高，能够在波形变化不大的情况下改变摆动频率（恒曲率摆动）。这些结果表明，超活化和活化精子的鞭毛摆动本质上是不同的模式，并且超活化是从恒曲率摆动到恒频摆动的模式转换。对鞭毛弯曲的详细分析表明，超活化过程中近端中段曲率的增加是由于弯曲之间几乎笔直区域中微管滑动总长度的增加，而微管滑动速率几乎保持不变。
