Spindle and chromosomal alterations in metaphase II oocytes.

The spindle apparatus is a vital structure and must be structurally intact for proper segregation of the oocyte's genetic material during metaphase II. Endometriosis, oxidative stress, and cryopreservation can all adversely affect the structural integrity of the spindle, potentially resulting in aneuploidy and spontaneous abortion of the embryo. Advances in spindle imagery have made it possible to visualize the effects of environmental stresses on spindle structure. Deviation from an oocyte's normal environment can seriously impair the positioning and integrity of the spindle. Oocytes cryopreservation causes depolymerization and repolymerization of the spindle. Oocytes can also be preserved in an immature state for later in vitro maturation. A comprehensive understanding of the spindle behavior is paramount for the effective manipulation of oocytes in an assisted reproductive setting.