Phenotypes for Pten Tg(GFAP-cre)25Mes MGI:4830362 MGI Mouse

lethality at weaning, complete penetrance ( J:100428 )

• death occurs around P21

abnormal Bergmann glial cell differentiation ( J:100428 )

• premature differentiation of Bergmann glia leading to extensive layering defects

abnormal cerebellum development ( J:100428 )

• cerebella layering defects

• before P3, cerebella are enlarged but the external granule layer (EGL) and cerebellar lobules are normal and Purkinje cell position is normal

• however, after P6, mutants show a marked cerebellar enlargement and lack internal granule layer and folia

abnormal cerebellar foliation ( J:100428 )

• loss of foliation after P6

increased brain size ( J:100428 )

abnormal cerebellar Purkinje cell layer ( J:100428 )

• Purkinje layer defect is first seen at P4-P6 and by P9, numerous Purkinje neurons are randomly scattered

abnormal Bergmann glial cell morphology ( J:100428 )

• disruption of Bergmann glial layering

ectopic Bergmann glia cells ( J:100428 )

• some Bergmann cell bodies are randomly distributed at P7 and lose their contacts to the pial surface and are positioned deep within the internal granule layer region

ectopic Purkinje cell ( J:100428 )

• Purkinje cell layer is normal at P3 but there are many ectopic Purkinje cells by P9

abnormal cerebellar granule layer morphology ( J:100428 )

• lack of an organized internal granule layer (IGL) at P6

• severe granule neuron layering defects

abnormal cerebellar granule cell morphology ( J:100428 )

• mutants exhibit granule neuron migration defects, with granule neurons failing to migrate to the internal granule layer and accumulating in the molecular layer (ML)

• granule neurons are resistant to low potassium-induced cell death under serum deprivation conditions

enlarged cerebellum ( J:100428 )