Phenotypes Associated with This Genotype

Genotype
MGI:3707497

• Allelic Composition: Rb1^tm2Brn/Rb1^tm2Brn; Tg(En2-cre)22Alj/0
• Genetic Background: involves: 129P2/OlaHsd * CD-1

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

nervous system

astrocytosis ( J:83783 )

• a brisk widespread astrogliosis in observed in the IGL

increased neuron apoptosis ( J:83783 )

• increase in apoptotic rate is seen at P15 in vermis of mutants; most apoptotic cells are found in the inner half of the external granule layer and in the inner granule layer; rate is similar at P30 and is accelerated compared to Rb1 single mutant mice

• there is no detectable Purkinje cell apoptosis

abnormal neuronal precursor proliferation ( J:83783 )

• at P15, number of proliferating granule cell precursors in cerebellum is higher than in controls; at P20, proliferation in external granule layer (EGL) of vermis is increased while in the internal granule layer (IGL), higher proliferation is detected at P8

abnormal cerebellum external granule cell layer morphology ( J:83783 )

• at P 15, thickness of the external granule layer (EGL) is greater (4-5 cells thick) relative to wild-type (1 or 2 cells thick)

thin external granule cell layer ( J:83783 )

• at P20, mice have a persisten thin EGL with granule cell precursors still migrating through the molecular layer

abnormal brain interneuron morphology ( J:83783 )

• interneurons of molecular layer of cerebellum are substantially reduced in number at P20, which is most pronounced in lobules VI and VII

abnormal cerebellar cortex morphology ( J:83783 )

• numbers of granule, basket and stellate neurons are considerably reduced compared to wild-type

abnormal Purkinje cell morphology ( J:83783 )

• Purkinje cells are slightly irregularly arranged and have moderately enlarged somata and nuclei

• Purkinje cells in vermis appear disarranged, and occasionally show enlarged nuclei with abnormal shapes and reduced dendritic arborization

abnormal cerebellar granule layer morphology ( J:83783 )

• thickness and cellularity of the internal granule layer (IGL ) is reduced at P20 compared to wild-type; this is most pronounced in lobules VI and VII

abnormal cerebellar granule cell morphology ( J:83783 )

• numbers are severely reduced in cerebellum

cellular

astrocytosis ( J:83783 )

• a brisk widespread astrogliosis in observed in the IGL

increased neuron apoptosis ( J:83783 )

• increase in apoptotic rate is seen at P15 in vermis of mutants; most apoptotic cells are found in the inner half of the external granule layer and in the inner granule layer; rate is similar at P30 and is accelerated compared to Rb1 single mutant mice

• there is no detectable Purkinje cell apoptosis

abnormal neuronal precursor proliferation ( J:83783 )

• at P15, number of proliferating granule cell precursors in cerebellum is higher than in controls; at P20, proliferation in external granule layer (EGL) of vermis is increased while in the internal granule layer (IGL), higher proliferation is detected at P8