Effects of Cooling and Rewarming on the Meiotic Spindle and the Developmental Potential of the Mouse Oocytes

Abstract: In order to evaluate the effects of cooling on the meiotic spindles， development potential of mouse oocytes and the reversibility of the spindle's damage， the Metaphase-II mouse oocytes were exposed at room temperature (24 ℃) or 4 ℃ for 1， 2， 4 or 24 h and part of the oocytes renew by culturing at 37 ℃ for 1 or 2 h. The early developmental potential of these oocytes was analyzed by parthenogenetic activation and the dynamic of damage and reconstruction of the spindles was detected by confocal microscopy. The results displayed that the damage of the spindles after cooling relied obviously on the temperature and time of the treatment. The damage of spindles after low temperature treatment for less than 4 h， in spite of 24 or 4 ℃， was strongly reversible， and the oocytes could reconstruct normal spindle configuration， but the early developmental potential of parthenogenetic embryos derived form these oocytes was evidently decreased. The different oocyte抯 age had no influence to the injury of the oocytes by cooling. The results suggest that the operative time of cell engineering procedure using oocytes should be shorten as much as possible.
    

CSTR: 32200.14.cjcb.2009.03.0019