Institute of Environmental Health Sciences and Department of Biochemistry and Molecular Biology, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
Biol Reprod. 2011 May;84(5):1005-15. doi: 10.1095/biolreprod.110.088773. Epub 2011 Feb 3.
Motile cilia and flagella exhibit many waveforms as outputs of dynein activation sequences on the highly conserved axoneme. Motility change of sperm in the reproductive tract is difficult to study and remains an important area of investigation. Sperm typically execute a sinusoidal waveform. Increased viscosity in the medium induces somewhat unusual arc-line and helical waveforms in some sperm. However, whether the latter two waveforms occur in vivo is not known. Using green fluorescence protein imaging, we show that Drosophila sperm in the uterus move in circular foci via arc-line waves, predominantly in a tail-leading orientation. From the uterus, a small fraction of the sperm enters the seminal receptacle (SR) in parallel formations. After sperm storage and coincident with fertilization of the egg, the sperm exit the SR via head-leading helical waves. Consistent with the observed bidirectional movements, the sperm show the ability to propagate both base-to-tip and tip-to-base flagellar waves. Numerous studies have shown that sperm motility is regulated by intraflagellar calcium concentrations; in particular, the Pkd2 calcium channel has been shown to affect sperm storage. Our analyses here suggest that Pkd2 is required for the sperm to adopt the correct waveform and movement orientation during SR entry. A working model for the sperm's SR entry movement is proposed.
纤毛和鞭毛表现出许多波形，作为轴丝上的动力蛋白激活序列的输出。生殖道中精子的运动变化难以研究，仍然是一个重要的研究领域。精子通常执行正弦波波形。在某些精子中，介质的粘度增加会导致稍微不寻常的弧形线和螺旋形波形。然而，后两种波形是否存在于体内尚不清楚。通过绿色荧光蛋白成像，我们发现在子宫中的果蝇精子通过弧形线波以圆形焦点移动，主要以尾端领先的方向移动。从子宫中，一小部分精子以平行的形式进入精液接收囊（SR）。在精子储存后，与卵子受精同时，精子通过头端螺旋波从 SR 中逸出。与观察到的双向运动一致，精子显示出传播从基端到顶端和从顶端到底端的鞭毛波的能力。许多研究表明，精子运动受鞭毛内钙离子浓度的调节；特别是 Pkd2 钙通道已被证明影响精子储存。我们这里的分析表明，Pkd2 是精子在进入 SR 时采用正确波形和运动方向所必需的。提出了一个用于精子进入 SR 运动的工作模型。
