A Glutamine-Rich Factor Affects Stem Cell Genesis in Leech

Figure 1

Schematic of early development in glossiphoniid leeches. After several asymmetric cleavages, proteloblasts DM (stage 4) and NOPQ (stage 5) are stereotypically positioned on the embryo’s surface. A series of unequal divisions leads to five bilaterally paired stem cells (10 total), or teloblasts (gray cells: M, N, O, P, Q), that give rise to chains of segmental founder cells called bandlets (stages 7, 8). By epiboly, bandlets move across the surface of the embryo (arrows, stage 8) and coalesce to form the segmental mesodermal and ectodermal tissue. Modified from Hohenstein and Shain [10].