This is one of 4 grouped time lapse movies (CIL 11958-11962) revealing the responses of a meiotic oocyte spindle to various forms of micromanipulation by a glass microneedle. The needle is inserted, from below, through the egg cortex to the inner pole of the metaphase spindle. This movie, speeded up about 10-fold, shows the transient puckering in the cell membrane showing that the spindle pole is attached to the cortex. After the attachment has been broken, the cell surface rounds back up. The spindle is made visible by the use of polarizing optics.
See DA Lutz et al 1988. Micromanipulation of the asymmetric positioning of the maturation spindle in Chaetopterus sp oocytes. Cell Motil Cytoskel 11:83-96. This paper includes stills of similar experiments.