Scientist: Research Projects: Mouse Mutation Database
The primary function of the Mutant Mouse Profile is to list newly
identified, mouse models of human craniofacial disorders. Research
on these models is being carried out in the Mouse Mutant Resource
at The Jackson Laboratory. Several mouse mutants with skull or facial
dysmorphisms are already available from the Mouse Mutant Resource.
The table below lists some of the mouse craniofacial mutants. The
table gives information on the mutation by mutant gene symbol, name,
and a brief description of the mutant phenotype.
For more information on more craniofacial mouse mutants see:
Symbol
|
Name
|
Description
|
Foxc1
|
congenital hydrocephalus
|
Foxc1 is a spontaneously autosomal
recessive
mutation on mouse Chromosome 13. Homozygotes die at birth,
probably from inability to breathe. They have bulging
hemorrhagic cerebral hemispheres and open eyelids,
urogenital abnormalities, and severely abnormal
skull,cervical vertebrae, sternum, laryngeal cartilages,
and hyoid bone. Many other parts of the skeleton are mildly
affected, and there are numerous defects of glands and
their ducts in the head region. Some heterozygotes show a
much less severe type of defect. Most of the defects in the
head region are probably secondary to the severe
displacements created by the hydrocephalus. More detailed
information and references may be found at the Mouse Genome
Database (MGD) website.
|
Edardd
|
crinkled
|
Crinkled is an autosomal recessive mutation on Chromosome
9. Homozygotes have coats that are thinner than normal and
contain only one type of hair resembling an abnormal awl,
rather than the four types of hair of the normal coat.
There is a bald patch behind the ears, bald tail, kinks at
the tail tip, absence of Meibomian glands, a respiratory
disorder, modification of the agouti pattern, abnormal
molars and incisors , and probably abnormalities of many
exocrine glands. Viability and breeding performance are
somewhat reduced. Myelin abnormalities have been described
in the brains of old crinkled mice. Heterozygotes have
normal coats, but many have slight abnormalities of the
upper molars. More detailed information and references may
be found at the Mouse Genome Database (MGD) website.
|
din
|
dense incisors
|
Dense incisors is an autosomal recessive spontaneous
mutation on mouse Chromosome 16. The mutation interferes
with complete eruption of the incisors. Although initial
eruption is similar in mutants and controls, eruption is
subsequently arrested. Radiographic examinations show that
continued dentin formation in the unerupted incisors
gradually occludes the pulp chambers and creates a dense
incisor. Homozygotes are also small in size, have small ear
pinnae, and coat color dilution. Although din maps near the
pituitary factor 1 (Pit1) gene, it is not a mutation in
Pit1. More detailed information may be found in Sweet et
al., J. Hered., 1996; 87(2):162-167.
(Abstract)
|
Edar
|
downless Jackson
|
Downless Jackson is an autosomal recessive mutation on
Chromosome
10. Homozygotes have a thin and shiny coat with bald
patches behind the ears and a bald tail. The incisors may
be abnormal or absent and the molars abnormal. Instead of
the normal four types of hair, only one type, resembling an
abnormal awl, is found. More detailed information and
references may be found at the Mouse Genome Database (MGD)
website.
|
Apaf1
|
forebrain overgrowth
|
Apaf1 is a spontaneous autosomal
recessive mutation on
mouse Chromosome 10. The fog mutation produces facial,
forebrain, and lumbo-sacral defects, which appear to result
from excessive growth or cellular proliferation leading to
abnormalities in neural tube closure. Three unique features
of the mutant are (1) growth of telancephalon cells into
the surrounding mesenchyme, (2) presence of an
encephalocele through the midline cleft in some mutants,
and (3) dissociation of the tail defect from the caudal
neural tube defect. More detailed information may be found
in Harris et al., Teratology 1997; 55(4):231-240.
(Abstract)
|
Ptch
|
mesenchymal dysplasia
|
Ptch is a spontaneous autosomal recessive
mutation on
mouse Chromosome 13. Homozygotes have a shortened face,
wide set eyes, excessive skin, belly spot, kinked tail,
preaxial polydactyly, and thickened foot pads. Alizarin
preparations reveal mineralization of tendons and multiple
skeletal defects. Neither sex breeds; male mutants have
cryptorchid testes. More detailed information and
references may be found at J Hered
, 1996, 87(2):87-95.
(Abstract)
|
Csf1
|
osteopetrosis
|
The osteopetrosis mutation is a spontaneous, autosomal
recessive mutation in the macrophage colony stimulating
Csf1
homozygotes can be recognized at 10 days of age by absence
of incisors and by a domed skull. They survive weaning if
provided with soft food, but viability is reduced and
breeding performance is very poor. The basis of the
skeletal defects is a severely restricted capacity for bone
remodelling, due to a rapid loss of osteoclasts after birth
(within 3--4). Young homozygotes have excessive
accumulations of bone with lack of marrow cavities,
increases in bone matrix formation and in parafollicular
(calcitonin-secreting) cells of the thyroid, and normal
serum calcium but low serum phosphate. Cranial flat bone
formation in this mutant mouse is abnormal, as is the
masseter muscle, probably due to failure to produce teeth
and the resulting reduction in development of periodontal
ligaments. More detailed information and references may be
found at the Mouse Genome Database (MGD) website.
|
oto
|
otocephaly
|
Otocephaly is an autosomal recessive mutation that was
probably induced by X irradiation of a male homozygous for
the Chr 1 inversion In(1)1Rk. oto is either within or
closely linked to the inversion. Homozygotes examined after
12 days of gestation may show microphthalmia, reduced or
absent jaws, cyclopia, fused maxillary prominences, or
complete absence of the face. Some mutant embryos can be
identified as early as the 0 to 4 somite stage when they
show extreme truncation of the anterior neural area.
Penetrance in homozygotes is variable and dependent on
genetic background. More detailed information and
references may be found at the Mouse Genome Database (MGD)
website.
|
Eda
|
tabby
|
The tabby mutation is an X-linked semi-dominant mutation
that causes striping in heterozygous females due to X-
inactivation. Tabby males appear mostly yellow. Males breed
satisfactorily, homozygous females are often sterile, and
heterozygous females are fully fertile. Hemizygous males
and homozygous females are characterized by absence of
guard hairs and zigzags in the coat, a bald patch behind
the ear, bald tail with a few kinks near the tip, reduced
aperture of the eyelids, a respiratory disorder, a modified
agouti pattern, and a reduced number of vibrissae. The
incisors may be reduced or absent, and the molars are
usually smaller than normal with the third molar often
absent. There are defects of many endocrine glands. Ta is
probably the mouse homologue of the human familial X-linked
disorder hypohidrotic ectodermal dysplasia (EDA)(MIM
305100) based on the similarity in phenotypes - hypoplasia
of sweat glands, teeth, and hair - and on homologous
mapping. Exogenous epidermal growth factor can reverse
phenotypic features of Ta mice, advancing the delayed
opening of eyelids and eruption of incisors. More detailed
information and references may be found at the Mouse Genome
Database (MGD) website.
|
Ts
|
tail short
|
Ts is a semi-dominant spontaneous mutation on
Chromosome 11. Homozygotes are detectable at 3.5 days post-
coitus as retarded pale-staining morale; all are dead by
5.5 days. Heterozygotes are recognizable by their shortened
chinked tails, smaller than normal size, and numerous
skeletal abnormalities including vertebral fusion's and
dyssymphyses, bilateral asymmetry of the length of the
humerus and tibia, triphalangy of digit 1 of the forefoot,
an extra pair of ribs, and often a shortened and highly
abnormal skull. Embryonic studies of heterozygotes revealed
disintegration of the notochord, basement membrane, and
perinotochordal sheath as early as 9-1/2 days of gestation.
There is a prenatal anemia at 13 to 17 days which
disappears before birth. More detailed information and
references may be found at the Mouse Genome Database (MGD)
website.
|
Author: Muriel Davisson
Content: 1998
Last modified: Nov 21,
2003
Last Updated:
9/9/03
|