Teloblast
![Teloblasts divide asymmetrically to form small blast cells which wrap around the embryo and extend rostrally. Here, the embryo is shown at late stage 7 (upper right). The N, O, P, Q, and M teloblasts are always positioned in the same relative orientations (lower left).](/Images/godic/202502/15/Wiki3_fig11005.jpg")
![O and P teloblasts have very different cell division patterns. The patterns of stereotyped mitoses for other teloblasts can be found here:[4]](/Images/godic/202502/15/OPteloblast1005.jpg")
A teloblast is a large cell in the embryos of clitellate annelids which asymmetrically divide to form many smaller cells known as blast cells. These blast cells further proliferate and differentiate to form the segmental tissues of the annelid. Teloblasts are well studied in leeches, though they are also present in the other major class of clitellates: the oligochaetes.