Phenotypes associated with this allele

• Allele Symbol: am
• Allele Name: amputated
• Allele ID: MGI:1856665
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	am/am	involves: 101 * C3H	MGI:4361340
hm2	am/am	involves: 101 * CBA	MGI:4361341
hm3	am/am	Not Specified	MGI:2654901

Genotype
MGI:4361340

hm1

• Allelic Composition: am/am
• Genetic Background: involves: 101 * C3H

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

embryo

abnormal paraxial mesoderm morphology ( J:6007 )

• at embryonic day 9.5 the primary mesenchyme adjacent to the primitive streak has only a few large intercellular spaces with the areas of cell contact made of gap junctions and occasionally tight junctions, whereas normal primary mesoderm has many small intercellular spaces and only short areas of cell to cell contact

abnormal somite development ( J:6007 )

• explanted somite tissue has fewer bipolar cells than normal and diminished cell migration, forming clumps of cells instead of spreading out

impaired somite development ( J:6007 )

cellular

abnormal cell adhesion ( J:6007 )

• explanted somites show extensive marginal cell-cell contact and cell contacts are maintained over a longer period compared with cultures of normal explanted somites

skeleton

abnormal sclerotome morphology ( J:6007 )

• by embryonic day 9.5 the cells of the sclerotomes are aggregated in small clumps with greater areas of cell contact than normal, filopodia that form an abnormal tangled web instead of being stretched out between cells, more extensive gap junctions, a higher frequency and longer length of desmosome-like structures and more complex desmosome-like structures

growth/size/body

decreased body length ( J:6007 )

• shortened body axis by embryonic day 8

Genotype
MGI:4361341

hm2

• Allelic Composition: am/am
• Genetic Background: involves: 101 * CBA

embryo

abnormal rostral-caudal body axis extension ( J:6011 )

decreased embryo size ( J:6011 )

• homozygotes are shorter by embryonic day 9.5, with a shortened trunk, and the tail fails to grow

abnormal paraxial mesoderm morphology ( J:6011 )

abnormal frontonasal mesenchyme morphology ( J:6105 )

• embryonic naso-frontal mesenchyme has larger areas of intercellular contact with more extensive gap junctions, more extensive desmosome-like junctions, filopods embedded in neighboring cells, and tangles of filopidia

abnormal primitive streak regression ( J:6011 )

• retarded regression of the primitive streak is theorized to result from reduced cell motility

decreased somite size ( J:6011 )

• somites are smaller than normal at all levels of the body axis

growth/size/body

palatal shelf hypoplasia ( J:6105 , J:6435 )

• at embryonic day 14.5 the first palatal rugae are found, but there is little to no downgrowth of the palatal shelves from the roof of the mouth (J:6435)

• clumping of mesoderm cells in the palatal shelves, rather than separation and spreading out as in normal mesoderm, causes failure of the shelves to grow and results in cleft palate (J:6435)

abnormal palatal rugae morphology ( J:6435 )

cleft secondary palate ( J:6435 )

• in all homozygotes due to the failure of the palates to rotate (elevate) and fuse

short snout ( J:6105 )

• at embryonic day 12.5 retarded growth of the naso-frontal region is evident and at embryonic day 16.5 the bones associated with the snout are greatly telescoped together

abnormal head shape ( J:6435 )

• at embryonic day 14.5 the head is blunter anteriorly and broader than normal

broad head ( J:6435 )

shortened head ( J:6435 )

decreased embryo size ( J:6011 )

• homozygotes are shorter by embryonic day 9.5, with a shortened trunk, and the tail fails to grow

abnormal frontonasal mesenchyme morphology ( J:6105 )

• embryonic naso-frontal mesenchyme has larger areas of intercellular contact with more extensive gap junctions, more extensive desmosome-like junctions, filopods embedded in neighboring cells, and tangles of filopidia

limbs/digits/tail

abnormal tail development ( J:6011 )

• the tail fails to develop

absent tail ( J:6011 )

skeleton

short mandible ( J:6105 )

• shortened by embryonic day 16.5

short maxilla ( J:6105 )

• shortened by embryonic day 16.5

abnormal intervertebral disk development ( J:6011 )

• embryos show anomalies of vertebral cartilage condensation and at later stages in development vertebral fusions are found

fusion of vertebral bodies ( J:6011 )

craniofacial

short mandible ( J:6105 )

• shortened by embryonic day 16.5

short maxilla ( J:6105 )

• shortened by embryonic day 16.5

abnormal nasal pit morphology ( J:6105 )

• by embryonic day 10.5 the olfactory pit is not as deeply invaginated as normal

palatal shelf hypoplasia ( J:6105 , J:6435 )

• at embryonic day 14.5 the first palatal rugae are found, but there is little to no downgrowth of the palatal shelves from the roof of the mouth (J:6435)

• clumping of mesoderm cells in the palatal shelves, rather than separation and spreading out as in normal mesoderm, causes failure of the shelves to grow and results in cleft palate (J:6435)

abnormal palatal rugae morphology ( J:6435 )

cleft secondary palate ( J:6435 )

• in all homozygotes due to the failure of the palates to rotate (elevate) and fuse

short snout ( J:6105 )

• at embryonic day 12.5 retarded growth of the naso-frontal region is evident and at embryonic day 16.5 the bones associated with the snout are greatly telescoped together

abnormal head shape ( J:6435 )

• at embryonic day 14.5 the head is blunter anteriorly and broader than normal

broad head ( J:6435 )

shortened head ( J:6435 )

respiratory system

abnormal nasal pit morphology ( J:6105 )

• by embryonic day 10.5 the olfactory pit is not as deeply invaginated as normal

cellular

abnormal cell adhesion ( J:6105 , J:6435 )

• at embryonic day 9.5 electron microscopy of the naso-frontal mesenchyme shows more extensive regions of contact between cells than in normal embryos, including frequent desmosome-like junctions and occasional knotted bundles of interdigitating cellular processes that are full of microfibrils, and at embryonic day 10.5 there are fewer elongated filopodia, less extensive rough endoplasmic reticulum and fewer mitochondria than in normal naso-frontal mesenchyme (J:6105)

digestive/alimentary system

palatal shelf hypoplasia ( J:6105 , J:6435 )

• at embryonic day 14.5 the first palatal rugae are found, but there is little to no downgrowth of the palatal shelves from the roof of the mouth (J:6435)

• clumping of mesoderm cells in the palatal shelves, rather than separation and spreading out as in normal mesoderm, causes failure of the shelves to grow and results in cleft palate (J:6435)

abnormal palatal rugae morphology ( J:6435 )

cleft secondary palate ( J:6435 )

• in all homozygotes due to the failure of the palates to rotate (elevate) and fuse

endocrine/exocrine glands

abnormal Rathke's pouch development ( J:6435 )

• the opening to Rathke's pouch persists at embryonic day 12.5

nervous system

abnormal Rathke's pouch development ( J:6435 )

• the opening to Rathke's pouch persists at embryonic day 12.5

Genotype
MGI:2654901

hm3

• Allelic Composition: am/am
• Genetic Background: Not Specified

mortality/aging

neonatal lethality, complete penetrance ( J:13423 )

• homozygotes die neonatally

craniofacial

shortened head ( J:13423 )

homeostasis/metabolism

edema ( J:13423 )

• the body is edematous dorsally

limbs/digits/tail

abnormal forelimb morphology ( J:13423 )

• most forelimb bones are present but appear abnormal

short limbs ( J:13423 )

• at late stages of gestation, limbs appear to be severed close to the trunk

absent tail ( J:13423 )

• mutant fetuses lack a tail

skeleton

rib fusion ( J:13423 )

• some ribs are fused

abnormal vertebrae morphology ( J:13423 )

• remaining vertebrae appear disorganized

absent vertebrae ( J:13423 )

• vertebrae of the lumbo-sacro caudal region are missing

growth/size/body

shortened head ( J:13423 )