Does congression failure delay anaphase onset?
During mitotic cell division, the presence of a misaligned chromosome delays the onset of anaphase (Burke 2000; Shah and Cleveland, 2000). Hence, we wondered if abnormalities in chromosome congression during the first meiotic division would induce a similar delay. To assess this, we focused on the XYPOS female since the incidence of abnormalities at MI was high and, unlike the LHßCTP female, not complicated by phenotypic and genetic variability. We approached the question in two ways. First, we compared the kinetics of the first meiotic division in oocytes from XYPOS and control females for evidence of meiotic delay. Surprisingly, not only were we unable to detect a subset of cells that were delayed or arrested at MI, but comparison studies of the number of oocytes that had progressed beyond metaphase I after only 6 or 8 h in culture revealed a significant difference between oocytes from XYPOS and control females, suggesting an acceleration in anaphase onset among oocytes from XYPOS fe
