Symmetry breaking in the female germline cyst

In many animals, only one cell from a cyst of germ cells is selected to become the oocyte. Using fruit flies as a model, Nashchekin et al . identified the microtubule minus end-binding protein Patronin/CAMSAP as a key factor for specifying oocyte fate. Patronin amplifies an initial asymmetry provided by the fusome to form a noncentrosomal microtubule network focused on one cell, along which dynein transports oocyte fate determinants. This mechanism for selecting a single oocyte may be shared in other organisms. —BAP