Access

News and Views

Nature Cell Biology 4, E232 (1 October 2002) | doi:10.1038/ncb1002-e232

First mitotic division: getting it right at the start

Patrick P. L. Tam

At fertilization, the mouse oocyte completes the second meiotic division and cleaves asymmetrically into a large daughter oocyte and a small second polar body (PB). By convention, the PB marks the animal pole of the zygote and the diametrically opposite side is, by default, the vegetal pole.