CYTOKINESIS - CLEAVAGE FURROW ESTABLISHMENT IN CYLINDRICAL SAND DOLLAR EGGS
CYTOKINESIS - CLEAVAGE FURROW ESTABLISHMENT IN CYLINDRICAL SAND DOLLAR EGGS
复制标题
DOI：
10.1002/jez.1402170307
复制
发表时间：
1981-01-01
影响因子：
--
通讯作者：
RAPPAPORT, R
中科院分区：
文献类型：
--
作者：
RAPPAPORT, R
通过将受精卵限制在短长度的毛细管中，使它们重塑成细长的圆柱体，可以控制有丝分裂器的方向和随后的分裂沟以及从有丝分裂器到圆柱形细胞表面的距离。该技术使极性区域易于实验，并在第一次和第二次裂解之前使用。当赤道表面能够形成一个完整的，永久的沟，可以独立于有丝分裂装置的作用的时间是通过在第二次分裂时从一对圆柱形细胞中的一个吸出有丝分裂装置并计时操作和控制细胞中沟的出现之间的间隔来确定的。当有丝分裂装置在对照分裂前4分钟或更短时间内被移除时，被操作的细胞分裂，但当同样的操作在对照分裂前5分钟或更长的时间内完成时，在被操作的细胞中不出现沟壑。有丝分裂装置和表面之间必要的相互作用可能在沟开始起作用前4分钟才完成；此后，有丝分裂器是可有可无的。星界中心之间的距离和它们辐射结构的范围在槽位确定后继续增长。在有丝分裂装置变得不可用之前，在其与表面相互作用期间进行的实验表明，通过振动和反复操作引起的两极搅动在连续施加直到出现沟槽时不会干扰分裂。改变极的形状不会影响解理；在第一次和第二次卵裂前，紫苑的极性细胞质和极性部分也没有吸出。尽管在大口径移液器中两种紫苑的极性部分被隔离，但也发生了解理。有丝分裂器沿其中线的长度反复串接，经常改变其外观，但不能阻止分裂。
By confining fertilized, denuded sand dollar (E. parma) eggs in short lengths of capillary tubing so that they were reshaped into elongate cylinders, it was possible to control the orientation of the mitotic apparatus and the subsequent cleavage furrow and the distance from the mitotic apparatus to the cylindrical cell surface. The technique left the polar regions accessible to experimentation and was used before 1st and 2nd cleavages. The time when the equatorial surface becomes capable of forming a complete, permanent furrow which can function independently of the mitotic apparatus was determined by aspirating the mitotic apparatus from 1 of a pair of cylindrical cells at 2nd cleavage and timing the interval between the operation and the appearance of the furrow in the control cell. When the mitotic apparatus is removed 4 min or less before control furrowing, the operated cell cleaves, but when the same operation is accomplished 5 min or more before control division, furrows do not appear in the operated cell. The necessary interaction between the mitotic apparatus and the surface probably is not completed until 4 min before the furrow initiates function; thereafter the mitotic apparatus is dispensable. The distance between astral centers and the extent of their radiate structure continue growing after the furrow position is established. Experiments performed before the mitotic apparatus becomes dispensible, during the period of its interaction with the surface, revealed that agitation of the poles by vibration and repeated manipulation did not interfere with division when imposed continuously until the furrow appeared. Changing the shape of the poles did not affect cleavage; neither did aspiration of polar cytoplasm and polar portions of asters before both 1st and 2nd cleavage. Cleavage also occurred despite sequestration of the polar portions of both asters in large-bore pipettes. Repeated skewering of the mitotic apparatus along the length of its midline often altered its appearance but did not prevent division.