Stem cell autotomy and niche interaction in different systems

Figure 8 Symmetric and asymmetric germline stem cell division in Lymantria dispar. Both symmetric and asymmetric GSC divisions occur in this insect species. Both are preceded by the division of the single cyst stem cell that is associated with a GSC (A to C). Asymmetric division is depicted in D1a to D1d. One of the daughter cells is oriented toward the AC and still forms projections, whereas the other daughter cell has no contact with the AC and is devoid of projections (D1b). Then this daughter cell “swivels” round toward the AC (D1d) and adopts a similar position as daughter cells have after a symmetric GSC division (D2a to D2c). In each case, the daughter cell that doesn’t form projections becomes the gonialblast (E to H) (from Klein[66]). GSCs: Germline stem cells; AC: Apical cell.