Saiki T, Hamaguchi Y
Biological Laboratory, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, O-okayama, Meguro-ku, 152-8551, Japan.
Dev Biol. 1998 Nov 1;203(1):62-74. doi: 10.1006/dbio.1998.9045.
Using ionophore-activated starfish eggs, the maternal centrosome accompanied by the female pronucleus (the egg centrosome) was confirmed to possess the ability for aster formation but generally not the capacity for reproduction. Inhibition of pronuclear fusion and removal of the male pronucleus and/or the sperm centrosome revealed that the egg centrosome lost its ability when it was only in the vicinity of the sperm centrosome. Hence, the entity that inactivated the egg centrosome was determined to be the adjacent sperm centrosome. When the second polar body was transplanted into a fertilized egg, its maternal centrosome (the polar body centrosome) organized an aster during cleavage; moreover, it possessed reproductive capacity. Furthermore, three different patterns of aster formation characterizing the sperm, egg, and polar body centrosomes occurred at each corresponding nucleus in the absence of nuclear fusion. When various kinds of centrosomes approached each other through nuclear fusion, there was observed only a pattern of aster formation at the fusion site that characterized a certain centrosome. Consequently, the sperm, polar body, and egg centrosomes were superior, intermediate, and inferior, respectively, in their ability for aster formation.
利用离子载体激活的海星卵，证实伴随雌原核的母中心体（卵中心体）具有形成星体的能力，但通常没有复制能力。抑制原核融合并去除雄原核和/或精子中心体后发现，卵中心体仅在精子中心体附近时就会失去其能力。因此，确定使卵中心体失活的实体是相邻的精子中心体。当第二极体移植到受精卵中时，其母中心体（极体中心体）在卵裂过程中形成星体；此外，它具有复制能力。此外，在没有核融合的情况下，精子、卵和极体中心体形成星体的三种不同模式分别出现在各自对应的细胞核处。当各种中心体通过核融合相互靠近时，在融合位点仅观察到一种以特定中心体为特征的星体形成模式。因此，精子、极体和卵中心体在形成星体的能力上分别为优、中、差。
