Phenotypes associated with this allele

• Allele Symbol: Rac1^tm1Jms
• Allele Name: targeted mutation 1, Institute of Medical Science, Japan
• Allele ID: MGI:1857700
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Rac1^tm1Jms/Rac1^tm1Jms	involves: 129S/SvEv * C57BL/6J	MGI:3589368
cn2	Emx1^tm1(cre)Ito/Emx1^+ Rac1^tm1Atai/Rac1^tm1Jms	involves: 129P2/OlaHsd * 129S/SvEv * C57BL/6 * ICR	MGI:3814361

Genotype
MGI:3589368

hm1

• Allelic Composition: Rac1^tm1Jms/Rac1^tm1Jms
• Genetic Background: involves: 129S/SvEv * C57BL/6J

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:52224 )

• no homozygous mutant fetuses are identified after E9.5

embryo

abnormal gastrulation ( J:52224 )

abnormal germ layer development ( J:52224 )

abnormal rostral-caudal body axis extension ( J:52224 )

• at E8.5, homozygotes fail to elongate along the anterior-posterior axis and remain small and spherical

decreased embryo size ( J:52224 )

• at E6.5, the embryonic portion of mutant embryos is severely reduced relative to the extraembryonic portion

abnormal embryonic epiblast morphology ( J:52224 )

• at E7.5, the embryonic ectoderm is irregularly folded

thick embryonic epiblast ( J:52224 )

• at E7.5, the embryonic ectoderm is abnormally thick

absent mesoderm ( J:52224 )

• homozygotes exhibit developmental arrest and apoptosis of newly formed mesodermal cells during gastrulation

absent somites ( J:52224 )

• at E8.5, homozygotes display absence of axial structures such as the neural tube and somites

abnormal embryonic-extraembryonic boundary morphology ( J:52224 )

• at E7.5, numerous pyknotic cells and cell fragments are detected in the space between the embryonic ectoderm and visceral endoderm

growth/size/body

decreased embryo size ( J:52224 )

• at E6.5, the embryonic portion of mutant embryos is severely reduced relative to the extraembryonic portion

cellular

increased apoptosis ( J:52224 )

• at E6.5, a few homozygotes begin to display pyknotic cells and cell fragments in specific areas of the proamniotic cavity and between the epiblast and visceral endoderm

Genotype
MGI:3814361

cn2

• Allelic Composition: Emx1^tm1(cre)Ito/Emx1⁺; Rac1^tm1Atai/Rac1^tm1Jms
• Genetic Background: involves: 129P2/OlaHsd * 129S/SvEv * C57BL/6 * ICR

mortality/aging

decreased survivor rate ( J:140575 )

• fewer than expected mice are present at P18 but the remainder of mice survive into adulthood

postnatal lethality, incomplete penetrance ( J:140575 )

• fewer than expected mice are present at P18

nervous system

abnormal brain commissure morphology ( J:140575 )

• mice exhibit reduced formation of interhemispheric commissural connections by inhibition of midline crossing

• however, the posterior and habenular commissures are normal

abnormal corpus callosum morphology ( J:140575 )

• myelinated fibers are reduced in the corpus callosum and anterior commissure compared to in control (Rac1^tm1Atai/Rac1⁺ Emx1^tm1(cre)Ito/Emx1⁺) mice

• retrograde dye labeling experiments demonstrate that contralateral projections of the callosal commissural axons are absent

decreased hippocampal commissure size ( J:140575 )

decreased anterior commissure size ( J:140575 )

• myelinated fibers are reduced in the corpus callosum and anterior commissure compared to in control (Rac1^tm1Atai/Rac1⁺ Emx1^tm1(cre)Ito/Emx1⁺) mice

abnormal telencephalon morphology ( J:140575 )

• neuron layers of the telencephalon cortex are thinner than in heterozygous controls (Rac1^tm1Atai/Rac1⁺ Emx1^tm1(cre)Ito/Emx1⁺) with sporadic distortions caused by abnormal cell clusters and nerve fibers

abnormal dentate gyrus morphology ( J:140575 )

• the dentate gyrus is disorganized

abnormal hippocampus pyramidal cell layer ( J:140575 )

• the pyramidal cell layer of the hippocampus is thinner than in control (Rac1^tm1Atai/Rac1⁺ Emx1^tm1(cre)Ito/Emx1⁺) mice

small hippocampus ( J:140575 )

abnormal barrel cortex morphology ( J:140575 )

• somatosensory cortex barrels are small in size and irregular in shape compared to in control (Rac1^tm1Atai/Rac1⁺ Emx1^tm1(cre)Ito/Emx1⁺) mice