Panzica Michelle T, Marin Harold C, Reymann Anne-Cecile, McNally Francis J
Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA.
BIOTEC TU Dresden, Dresden, Germany.
J Cell Biol. 2017 Aug 7;216(8):2273-2282. doi: 10.1083/jcb.201702020. Epub 2017 Jun 21.
Fertilization occurs during female meiosis in most animals, which raises the question of what prevents the sperm DNA from interacting with the meiotic spindle. In this study, we find that sperm DNA stays in a fixed position at the opposite end of the embryo from the meiotic spindle while yolk granules are transported throughout the embryo by kinesin-1. In the absence of F-actin, the sperm DNA, centrioles, and organelles were transported as a unit with the yolk granules, resulting in sperm DNA within 2 µm of the meiotic spindle. F-actin imaging revealed a cytoplasmic meshwork that might restrict transport in a size-dependent manner. However, increasing yolk granule size did not slow their velocity, and the F-actin moved with the yolk granules. Instead, sperm contents connect to the cortical F-actin to prevent interaction with the meiotic spindle.
在大多数动物中，受精发生在雌性减数分裂期间，这就引发了一个问题：是什么阻止精子DNA与减数分裂纺锤体相互作用。在本研究中，我们发现精子DNA在胚胎中位于与减数分裂纺锤体相对的固定位置，而卵黄颗粒由驱动蛋白-1运输至胚胎各处。在没有F-肌动蛋白的情况下，精子DNA、中心粒和细胞器与卵黄颗粒作为一个整体被运输，导致精子DNA位于距减数分裂纺锤体2微米范围内。F-肌动蛋白成像显示了一个细胞质网络，其可能以大小依赖的方式限制运输。然而，增加卵黄颗粒大小并未使其速度减慢，且F-肌动蛋白与卵黄颗粒一起移动。相反，精子内容物与皮质F-肌动蛋白相连，以防止与减数分裂纺锤体相互作用。
