Phenotypes associated with this allele

• Allele Symbol: Ncaph2^tm1.2Hiran
• Allele Name: targeted mutation 1.2, Tatsuya Hirano
• Allele ID: MGI:5703870
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ncaph2^tm1.2Hiran/Ncaph2^tm1.2Hiran	involves: C57BL/6 * C57BL/6J	MGI:5703884
cn2	Ncaph2^tm1.1Hiran/Ncaph2^tm1.2Hiran Tg(Nes-cre)1Kln/0	involves: C57BL/6 * C57BL/6J * SJL	MGI:5703889
cn3	Ncaph^tm1.1Hiran/Ncaph^tm1.2Hiran Ncaph2^tm1.1Hiran/Ncaph2^tm1.2Hiran Tg(Nes-cre)1Kln/0	involves: C57BL/6 * C57BL/6J * SJL	MGI:5703890

Genotype
MGI:5703884

hm1

• Allelic Composition: Ncaph2^tm1.2Hiran/Ncaph2^tm1.2Hiran
• Genetic Background: involves: C57BL/6 * C57BL/6J

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

mortality/aging

embryonic lethality, complete penetrance ( J:222181 )

• no homozygotes are obtained and none are seen at E12.5, indicating embryonic lethality

Genotype
MGI:5703889

cn2

• Allelic Composition: Ncaph2^tm1.1Hiran/Ncaph2^tm1.2Hiran; Tg(Nes-cre)1Kln/0
• Genetic Background: involves: C57BL/6 * C57BL/6J * SJL

cellular

abnormal cell nucleus morphology ( J:222181 )

• the numbers of chromocenters per nucleus in the ventricular zone are greatly decreased; this is due to hyperclustering of chromocenters and not due to loss of chromocenters

• hyperclustering of chromocenters occurs in neural stem cells and in postmitotic neurons

abnormal nucleolus morphology ( J:222181 )

• structure of nucleoli within the interphase nucleus is largely disorganized and the number of nucleoli per nucleus in the ventricular zone is decreased

• decrease in number of nucleoli occurs in neural stem cells and in postmitotic neurons

abnormal mitosis ( J:222181 )

• neural stem cells show unusually large, Hoechst-dense structures at prophase, however the kinetics of mitotic progression is normal

• chromosome segregation defects at anaphase and postmitotic cells at E16.5

• defects in mitotic chromosome architecture and segregation are more prominent than in mice conditionally deleted for Ncaph

• the numbers of chromocenters (the nuclear structure that forms from the association of pericentric heterochromatin from several different chromosomes during interphase) per nucleus in the ventricular zone are greatly decreased; this is due to hyperclustering of chromocenters and not due to loss of chromocenters

• hyperclustering of chromocenters occurs in neural stem cells and in postmitotic neurons

nervous system

abnormal cortical plate morphology ( J:222181 )

• apoptotic cells are seen in the cortical plate

abnormal cerebral cortex morphology ( J:222181 )

• cerebral cortices are highly disorganized by E19.5

• some apoptosis is seen in the developing cortices at E13.5

abnormal neuronal stem cell morphology ( J:222181 )

• numbers of neural stem cells are decreased at E16.5

decreased neuron number ( J:222181 )

• numbers of neurons are decreased at E16.5

abnormal neuronal stem cell physiology ( J:222181 )

• neural stem cells undergo apoptosis in the ventricular zone at E16.5

Genotype
MGI:5703890

cn3

• Allelic Composition: Ncaph^tm1.1Hiran/Ncaph^tm1.2Hiran; Ncaph2^tm1.1Hiran/Ncaph2^tm1.2Hiran; Tg(Nes-cre)1Kln/0
• Genetic Background: involves: C57BL/6 * C57BL/6J * SJL

cellular

abnormal cell nucleus morphology ( J:222181 )

• hyperclustering of chromocenters in neurons

abnormal mitosis ( J:222181 )

• mice exhibit postmitotic cells with tail-like structures, indicative of defective chromosome segregation

• mitotic chromosomes are highly disorganized at prometaphase in 87.8% of cells

• cells with abnormal chromosomes progress through mitosis, exhibiting chromosome bridges in anaphase and dumbbell-shaped nucleus in subsequent G1 phase

• hyperclustering of chromocenters (the nuclear structure that forms from the association of pericentric heterochromatin from several different chromosomes during interphase) in neurons

nervous system

abnormal cerebral cortex morphology ( J:222181 )

• cerebral cortices are disorganized at E16.5

• massive apoptosis in developing cortices at E13.5

thin cerebral cortex ( J:222181 )

• cerebral cortices are extremely thin at E16.5

abnormal neuronal stem cell morphology ( J:222181 )

• Sox2+ neural stem cells largely disappear

decreased neuron number ( J:222181 )

• neurons in the cortical plate are reduced at E16.5

• Brn2+ upper-layer (later born) neurons are depleted more severely than the Tbr1+ deep-layer (early born) neurons