Cerebellar growth in brain-selective conditional dystroglycan-null mice. Cerebellar growth and development from P2, P7, and P16 in control (A, D, G), GFAP-Cre/DG-null (B, E, H), and nestin-Cre/DG-null (C, F, I). Normal lobules and fissures are indicated in the P16 control cerebellum (G). In both nestin-Cre/DG-null and GFAP-Cre/DG-null mice, many lobule surfaces and fissures display abnormal numbers of ectopic cells (asterisks; *) on the cerebellar surface or between two adjacent lobules. The resulting pathology appears as fused fissures and heterotopic neurons. Basement membrane (arrows; ➛) at the glia limitans is continuous along the surface of controls (J). In nestin-Cre/DG-null cerebellum at P2 (K), a cluster of granule neurons (asterisk; *) is seen outside the glia limitans (arrowhead; ➤). Similar, but more extensive, pathology is seen at P7 (L) and P16 (M). Area measurements from mid-sagittal sections of control, GFAP-Cre/DG-null, and nestin-Cre/DG-null at P2, P7, and P16 (N). Error bars denote standard error of the mean. n = 3 for each group. EGL = external granule cell; IGL = internal granule cell layer; Scale bar: 40 μm (A-I), 40 μm (J-M).