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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Hoxb13tm1Mrc
targeted mutation 1, Mario R Capecchi
MGI:2655241
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Hoxb13tm1Mrc/Hoxb13tm1Mrc Not Specified MGI:2656748
cx2
Hoxb13tm1Mrc/Hoxb13tm1Mrc
Hoxd13tm1Mrc/Hoxd13tm1Mrc
involves: 129S7/SvEvBrd MGI:2656751


Genotype
MGI:2656748
hm1
Allelic
Composition
Hoxb13tm1Mrc/Hoxb13tm1Mrc
Genetic
Background
Not Specified
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Hoxb13tm1Mrc mutation (0 available); any Hoxb13 mutation (9 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
limbs/digits/tail
• increase in cell proliferation and decrease in apoptosis within the tail
• dorsal flexure of the tail
• caudal tail vertebrae are longer, thicker, and barrel shaped instead of bow tie shaped
• foramena of vertebrae are larger and bifid spinous processes are set farther apart due to the larger ectopic neural tube
• tail length is increased by approximately 1 cm

skeleton
• greater distance between the bifid spinous processes of caudal vertebra 1-6
• caudal tail vertebrae are longer, thicker, and barrel shaped instead of bow tie shaped
• foramena of vertebrae are larger and bifid spinous processes are set farther apart due to the larger ectopic neural tube

nervous system
• axons are defective in defasciculating from the segmental nerves
• overgrowth of the secondary neural tube
• reduced cell death and increased proliferation througout the secondary neural tube at E13.5 relative to heterozygotes
• mutants have 6-8 Tuj1+ cell layers in the neural tube compared to one inner undifferentiated ventricular layer and one outer, postmitotic Tuj1+ layer in controls
• peripheral nerve innervation is reduced in mutants
• segmental nerves that run the length of the tail appear thicker and do not extend as far caudally as controls; more processes enter the segmental nerves from ectopic dorsal root ganglia, but fewer ventral and lateral processes defasciculate to innervate the peripheral tissues of the tail
• ventral ramii, the nerve tracts within the ventral foramen, are larger than in heterozygous controls
• ectopic and supernumery dorsal root ganglion are seen at E13.5
• overgrowth of spinal cord; caudally expanded spinal cord persists from birth to adulthood
• the caudal extremity of the spinal cord, the conus medullaris, is located more posteriorly in mutants
• a mass of aberrant neural cells is seen in the caudal extremity of the cord
• newborn mutants contain a spinal cord with an intact central canal while no spinal cord, only the filum terminale, is seen in controls at this time
• 16 week old mutants contain an abnormal spinal cord complete with rudimentary dorsal root ganglia

embryo
• overgrowth of the secondary neural tube
• reduced cell death and increased proliferation througout the secondary neural tube at E13.5 relative to heterozygotes
• mutants have 6-8 Tuj1+ cell layers in the neural tube compared to one inner undifferentiated ventricular layer and one outer, postmitotic Tuj1+ layer in controls

behavior/neurological
• mutants exhibit a less pronounced tail-flicker response, however when tested for hot, cold, pressure, touch, or pain sensitivity, they are capable of sensing these stimuli

endocrine/exocrine glands
• ducts from ventral prostates are frequently swollen in older mutants (>1 year), however no reduction in duct tip numbers
• ventral prostate epithelial cells are simple cuboidal instead of the tall columnar epithelia seen in controls
• markers for prostate luminal epithelium are expressed but mislocalized, indicating that epithelial cells may lack polarity
• prostate ducts show reduced protein content indicating a reduction in secretory function of the ventral prostate

reproductive system
• ducts from ventral prostates are frequently swollen in older mutants (>1 year), however no reduction in duct tip numbers
• ventral prostate epithelial cells are simple cuboidal instead of the tall columnar epithelia seen in controls
• markers for prostate luminal epithelium are expressed but mislocalized, indicating that epithelial cells may lack polarity
• prostate ducts show reduced protein content indicating a reduction in secretory function of the ventral prostate

cellular
• axons are defective in defasciculating from the segmental nerves




Genotype
MGI:2656751
cx2
Allelic
Composition
Hoxb13tm1Mrc/Hoxb13tm1Mrc
Hoxd13tm1Mrc/Hoxd13tm1Mrc
Genetic
Background
involves: 129S7/SvEvBrd
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Hoxb13tm1Mrc mutation (0 available); any Hoxb13 mutation (9 available)
Hoxd13tm1Mrc mutation (0 available); any Hoxd13 mutation (24 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
endocrine/exocrine glands
• 50% reduction in the number of duct tips in the ventral prostate
• outgrowth of prostate ducts is reduced

reproductive system
• 50% reduction in the number of duct tips in the ventral prostate
• outgrowth of prostate ducts is reduced





Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
11/12/2024
MGI 6.24
The Jackson Laboratory