Phenotypes associated with this allele

• Allele Symbol: Ssb^tm1Rjma
• Allele Name: targeted mutation 1, Richard J Maraia
• Allele ID: MGI:3617648
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ssb^tm1Rjma/Ssb^tm1Rjma	involves: 129S/SvEv * C57BL/6	MGI:3618328
cn2	Ssb^tm1Rjma/Ssb^tm2.1Rjma Cd79a^tm1(cre)Reth/Cd79a^+	involves: 129S/SvEv * BALB/c	MGI:5569496
cn3	Ssb^tm1Rjma/Ssb^tm2.1Rjma Tg(Camk2a-cre)T29-1Stl/0	involves: 129S/SvEv * BALB/c * C57BL * C57BL/6	MGI:5569497

Genotype
MGI:3618328

hm1

• Allelic Composition: Ssb^tm1Rjma/Ssb^tm1Rjma
• Genetic Background: involves: 129S/SvEv * C57BL/6

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

mortality/aging

embryonic lethality between implantation and somite formation, complete penetrance ( J:105552 )

• no homozygotes detected from E6.0 onward

• possible that death occurs before implantation

embryo

inner cell mass degeneration ( J:105552 )

• inner cell mass begins to degenerate starting after E3.0

abnormal trophoblast giant cell morphology ( J:105552 )

• trophoblast more persistent than inner cell mass but cell nuclei smaller than controls

Genotype
MGI:5569496

cn2

• Allelic Composition: Ssb^tm1Rjma/Ssb^tm2.1Rjma; Cd79a^tm1(cre)Reth/Cd79a⁺
• Genetic Background: involves: 129S/SvEv * BALB/c

immune system

immune system phenotype ( J:207687 )

N • mice exhibit normal splenic CD4+ and CD8+ T cells

arrested B cell differentiation ( J:207687 )

• total block at the pro-B cell to pre-B cell transition

decreased B cell number ( J:207687 )

• severe

small spleen ( J:207687 )

• hyposplenia

decreased spleen weight ( J:207687 )

decreased IgG level ( J:207687 )

• absent

decreased IgM level ( J:207687 )

• absent

hematopoietic system

arrested B cell differentiation ( J:207687 )

• total block at the pro-B cell to pre-B cell transition

decreased B cell number ( J:207687 )

• severe

small spleen ( J:207687 )

• hyposplenia

decreased spleen weight ( J:207687 )

decreased IgG level ( J:207687 )

• absent

decreased IgM level ( J:207687 )

• absent

Genotype
MGI:5569497

cn3

• Allelic Composition: Ssb^tm1Rjma/Ssb^tm2.1Rjma; Tg(Camk2a-cre)T29-1Stl/0
• Genetic Background: involves: 129S/SvEv * BALB/c * C57BL * C57BL/6

nervous system

decreased brain weight ( J:207687 )

• after 5 weeks

• rapid decline from 13 to 25 weeks, slowed decline afterward

• at 59 to 79 weeks

decreased forebrain size ( J:207687 )

• postnatal loss of forebrain mass at 16 and 32 weeks

forebrain hypoplasia ( J:207687 )

• progressive cell loss

abnormal cerebral cortex morphology ( J:207687 )

• loss of cortical cytoarchitecture at 16 and 32 weeks

thin cerebral cortex ( J:207687 )

• progressive neurodegeneration in the cerebral cortex (starting at 16 weeks) and hippocampus starting

• severely diminished at 65 weeks

abnormal neuron morphology ( J:207687 )

• decrease in neuronal density at 16 and 32 weeks

hippocampus pyramidal cell degeneration ( J:207687 )

• in the CA1 and subiculum

• however, the CA3 and dentate gyrus are relatively spared

neurodegeneration ( J:207687 )

• progressive neurodegeneration in the cerebral cortex and hippocampus