Immunocytochemical Staining of the Metaphase II Spindle in Mammalian Oocytes

Investigation into microtubule function in mature mammalian oocytes in relation to cryopreservation is one area of study for the present authors. An increasing number of couples are seeking the assistance of physicians for reproductive dysfunction, and cryopreservation of gametes and embryos plays a role in this type of therapy (http://www.cdc.gov/nccdphp/drh/ART99/index99.htm ). To some individuals the cryopreservation of human embryos raises ethical concerns (1 ). Unfortunately, the success of oocyte cryopreservation is low. The metaphase II (MII) spindle in mature oocytes has been shown to be sensitive to the nonphysiologic conditions imposed upon cells during cryopreservation, and it is believed that the disruption of the MII spindle is a principal cause of the loss of developmental potential in frozen-thawed human oocytes (2 –4 ).