Mita M, Nakamura M
Biol Bull. 1992 Jun;182(3):298-304. doi: 10.2307/1542250.
The morphology of the midpiece in spermatozoa of the sea urchin Hemicentrotus pulcherrimus was investigated ultrastructurally with particular emphasis on an endogenous substrate providing energy for motility. The midpiece was composed of a single toroidal mitochondrion surrounding the flagellum. Several lipid bodies (0.1-0.2 μm in diameter) were contained in the space between the mitochondrial outer and inner membranes. Following incubation with seawater, spermatozoa began to swim and the lipid bodies became small and finally disappeared, coincident with a decrease in the level of phosphatidylcholine (PC), an endogenous substrate for energy metabolism. In contrast, during incubation in 100 mM K+-seawater, in which spermatozoa are immotile, there was no decrease in the level of PC and the lipid bodies remained intact. These results strongly suggest that the PC available for use in energy metabolism is located in the lipid bodies within mitochondria in the midpieces of H. pulcherrimus spermatozoa.
利用超微结构研究了海胆光棘球海胆精子中段的形态，特别强调了为运动提供能量的内源性底物。中段由围绕鞭毛的单个环形线粒体组成。线粒体外膜和内膜之间的空间中含有几个脂质体（直径0.1 - 0.2μm）。在与海水孵育后，精子开始游动，脂质体变小并最终消失，同时能量代谢的内源性底物磷脂酰胆碱（PC）水平下降。相反，在100 mM K + -海水中孵育时，精子不运动，PC水平没有下降，脂质体保持完整。这些结果有力地表明，可用于能量代谢的PC位于光棘球海胆精子中段线粒体中的脂质体内。
