Phenotypes Associated with This Genotype

Genotype
MGI:3639584

• Allelic Composition: Wnt1^tm1Brd/Wnt1^tm1Brd
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6J

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

mortality/aging

neonatal lethality, complete penetrance ( J:10730 )

• homozygotes develop to term but die within 24 hrs of birth

nervous system

decreased rhombomere 1 size ( J:10730 )

• at E9.5, homozygotes display a shorter than normal metencephalic rhombomere-1 (r1)

abnormal midbrain development ( J:10730 )

• at E9.5, the caudal two-thirds of the midbrain fail to develop whereas the remaining (presumably rostral) one-third is present

• notably, most of the neural tube and all non-neural tissues appear normal

abnormal cranial flexure morphology ( J:10730 )

• at E16.5, homozygotes show an abnormal cranial flexure due to neural tissue loss; however, the thalamus and pons appear normal

abnormal midbrain-hindbrain boundary development ( J:10730 )

• at E9.5, a normal midbrain-metencephalic junction fails to develop

absent midbrain ( J:10730 )

• by E14.5, most, if not all, of the mutant midbrain is absent

abnormal forebrain morphology ( J:10730 )

• at E9.5, absence of primitive brain tissue moves the forebrain caudally, resulting in a novel juxtaposition of rostral midbrain with caudal metencephalon

abnormal metencephalon morphology ( J:10730 )

• at E9.5, homozygotes show absence of rostral metencephalic tissue

• at E14.5 and E16.5, dorsally-derived cerebellar tissue is absent whereas the ventrally-derived pons is present

absent cerebellum ( J:10730 )

• by E14.5, homozygotes lack an identifiable cerebellum; in contrast, the posterior choroid plexus is present, and the cerebral hemisphere, diencephalon, myelencephalon, and spinal cord appear normal

skeleton

abnormal parietal bone morphology ( J:44094 )

• at E18.5, homozygotes lack part of the parietal bone, a non-crest derivative

craniofacial

abnormal parietal bone morphology ( J:44094 )

• at E18.5, homozygotes lack part of the parietal bone, a non-crest derivative

hematopoietic system

decreased thymocyte number ( J:75999 )

• at E15-E16, homozygotes show a 20-30% reduction in thymocyte number relative to wild-type embryos

• however, T cell maturation during fetal development appears unaffected

immune system

decreased thymocyte number ( J:75999 )

• at E15-E16, homozygotes show a 20-30% reduction in thymocyte number relative to wild-type embryos

• however, T cell maturation during fetal development appears unaffected

embryo

decreased rhombomere 1 size ( J:10730 )

• at E9.5, homozygotes display a shorter than normal metencephalic rhombomere-1 (r1)

endocrine/exocrine glands

decreased thymocyte number ( J:75999 )

• at E15-E16, homozygotes show a 20-30% reduction in thymocyte number relative to wild-type embryos

• however, T cell maturation during fetal development appears unaffected