In the large Drosophila melanogaster oocyte, asymmetrically
localised cell fate determinants specify the body axes and pattern the future embryo and fly, making it an ideal model for the study of RNA localisation.
What
these cell fate determinants are and how they are distributed when a stem cell divides is another big question.
Notch activity is antagonised by
the cell fate determinant Numb, which asymmetrically partitions at mitosis and «switches off» Notch signalling in one of the daughter cells (7).