Synemins H and M distribution during neural differentiation of mouse ES cells. Retinoic acid-treated EBs were immunolabelled for synemin H (A, D), synemin H/M (G, J, M), synemin L (P), nestin (B, H), GFAP (E, K) and β-III tubulin (N, Q). The heterogeneity of differentiated ES cells was observed. Synemin H and M were co-expressed with nestin in a subpopulation of neural precursors (A-C, G-I), also with GFAP in a subpopulation of glia-astrocyte precursors harboring low level of GFAP (D-F). In contrast, synemin expression became extinct when astrocytes expressing high level of GFAP (J-L). During neuronal differentiation, no synemin H or M was detected in the neuronal cell expressing β-III tubulin (M-O). However, synemin L was co-expressed with β-III tubulin in neurons (P-R). Syn: synemin; Nes: nestin; βIII Tub: β-III tubulin. Bar = 20 μm.