Phenotypes associated with this allele

• Allele Symbol: Itgb1^tm2Son
• Allele Name: targeted mutation 2, Arnoud Sonnenberg
• Allele ID: MGI:2154544
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Itgb1^tm2Son/Itgb1^tm2Son	either: 129P2/OlaHsd-Itgb1^tm2Son or (involves: 129P2/OlaHsd * FVB)	MGI:3703917
hm2	Itgb1^tm2Son/Itgb1^tm2Son	FVB.129P2-Itgb1^tm2Son	MGI:3704001

Genotype
MGI:3703917

hm1

• Allelic Composition: Itgb1^tm2Son/Itgb1^tm2Son
• Genetic Background: either: 129P2/OlaHsd-Itgb1^tm2Son or (involves: 129P2/OlaHsd * FVB)

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

mortality/aging

lethality throughout fetal growth and development, complete penetrance ( J:47279 )

• embryonic lethality between E11.5 and E16.5; none are recovered after E16.5

embryonic lethality during organogenesis, incomplete penetrance ( J:47279 , J:82463 )

• embryonic lethality between E11.5 and E16.5 (J:47279)

• Background Sensitivity: all mutants die at midgestation on the mixed 129P2/OlaHad and FVB background, however on a predominantly FVB background, a subset die at midgestation and a subset die shortly after birth (J:82463)

embryo

abnormal first pharyngeal arch morphology ( J:47279 )

• in some embryos, the maxillary component of the first branchial arch is missing, while in others, the mandibular component is missing

small first pharyngeal arch ( J:47279 )

• in most embryos at E11.5, the first branchial arch is shortened

small second pharyngeal arch ( J:47279 )

• at E11.5, in some embryos the second branchial arch is underdeveloped

abnormal left-right axis patterning ( J:47279 )

• the body of some embryos is abnormally twisted, resulting in an abnormal anterior-posterior axis

abnormal neural tube morphology ( J:47279 )

increased embryonic neuroepithelium thickness ( J:47279 )

• the neuroepithelium is grossly expanded

spina bifida ( J:47279 )

• the neural tube is open in some embryos at E11.5

kinked neural tube ( J:47279 )

• seen in some E11.5 embryos

wavy neural tube ( J:47279 )

• the neural tube is abnormally waved both rostrally and caudally at E11.5 in some embryos

nervous system

abnormal nervous system morphology ( J:82463 )

• Background Sensitivity: frequency of defects is much higher on the mixed 129P2/OlaHsd and FVB background (27.5%) than on a predominantly FVB background (7.4%)

abnormal neural tube morphology ( J:47279 )

increased embryonic neuroepithelium thickness ( J:47279 )

• the neuroepithelium is grossly expanded

spina bifida ( J:47279 )

• the neural tube is open in some embryos at E11.5

kinked neural tube ( J:47279 )

• seen in some E11.5 embryos

wavy neural tube ( J:47279 )

• the neural tube is abnormally waved both rostrally and caudally at E11.5 in some embryos

abnormal brain morphology ( J:47279 )

• small brain cavities

decreased hindbrain size ( J:47279 )

• some embryos at E11.5 lack part of the hindbrain

abnormal choroid plexus morphology ( J:47279 )

• the choroid plexus is aberrant, with only a rudimentary choroid plexus in some embryos

craniofacial

abnormal craniofacial morphology ( J:82463 )

• Background Sensitivity: frequency of defects is much higher on the mixed 129P2/OlaHsd and FVB background (27.5%) than on a predominantly FVB background (7.4%)

mandible hypoplasia ( J:47279 )

• the lower jaw is underdeveloped at E16.5 such that the palate is visible

micrognathia ( J:47279 )

abnormal first pharyngeal arch morphology ( J:47279 )

• in some embryos, the maxillary component of the first branchial arch is missing, while in others, the mandibular component is missing

small first pharyngeal arch ( J:47279 )

• in most embryos at E11.5, the first branchial arch is shortened

small second pharyngeal arch ( J:47279 )

• at E11.5, in some embryos the second branchial arch is underdeveloped

abnormal facial morphology ( J:47279 )

• jaws and the lower part of the face are underdeveloped and misformed

cardiovascular system

hemorrhage ( J:47279 , J:82463 )

• exhibit extravasation of red blood cells in various tissues at E11.5, including into the pericardial cavity (J:47279)

• Background Sensitivity: hemorrhage is observed on this mixed 129P2/OlaHsd and FVB background but not on a predominately FVB background (J:82463)

limbs/digits/tail

abnormal limb morphology ( J:47279 )

• the limbs are excentrically positioned with respect to the tail in some embryos

abnormal digit development ( J:47279 )

• digit development is delayed in one of two embryos that are recovered at E16.5

hematopoietic system

anemia ( J:47279 )

• of 13 embryos recovered at E12.5, 5 are severely anemic

cellular

abnormal cell adhesion ( J:47279 )

• MEF adhesion to laminin 1 and fibronectin is reduced

decreased fibroblast cell migration ( J:47279 )

• MEF migration on laminin 1, type IV collagen, and fibronectin is reduced

skeleton

mandible hypoplasia ( J:47279 )

• the lower jaw is underdeveloped at E16.5 such that the palate is visible

micrognathia ( J:47279 )

vision/eye

abnormal eye distance/ position ( J:47279 )

• in one embryo recovered at E16.5, one eye is displaced to the top of the head

growth/size/body

abnormal head morphology ( J:47279 )

• the head is abnormally smooth at E16.5

abnormal facial morphology ( J:47279 )

• jaws and the lower part of the face are underdeveloped and misformed

Genotype
MGI:3704001

hm2

• Allelic Composition: Itgb1^tm2Son/Itgb1^tm2Son
• Genetic Background: FVB.129P2-Itgb1^tm2Son

mortality/aging

perinatal lethality, incomplete penetrance ( J:82463 )

• Background Sensitivity: embryos surviving the first period of lethality (about 36%), develop further and are alive at E18.5, however most die at, or soon after, birth, unlike on a mixed 50% 129P2/OlaHsd and 50% FVB background, where none survive to birth

embryonic lethality during organogenesis, incomplete penetrance ( J:82463 )

• Background Sensitivity: while on a mixed 50% 129P2/OlaHsd/50% FVB background, all embryos die at midgestation, on the predominantly FVB background, a subset of embryos die between E13.5 and E14.5, while a subset survive to birth

growth/size/body

decreased body weight ( J:82463 )

• all pups alive on P1 are thinner and the male that survived to adulthood remains smaller than controls

abnormal head morphology ( J:82463 )

• head is abnormal between E8-E13.5

decreased body length ( J:82463 )

• all pups alive on P1 are shorter

decreased fetal size ( J:82463 )

• embryos surviving the first period of lethality are thinner and some are shorter, particularly evident between E17-E18.5

embryo

abnormal pharyngeal arch morphology ( J:82463 )

• branchial arches are abnormal between E8-E13.5

embryonic growth arrest ( J:82463 )

• a subset of embryos cease development between E13.5 and E14.5

open neural tube ( J:82463 )

• neural tube is open between E8-13.5

kinked neural tube ( J:82463 )

• between E8-13.5, the neural tube is kinked

abnormal placenta morphology ( J:82463 )

abnormal placenta labyrinth morphology ( J:82463 )

• 2 of 3 pale embryos show increased apoptosis in labyrinthine endothelial cells

abnormal placental labyrinth vasculature morphology ( J:82463 )

• the placental labyrinth of the pale embryos contains reduced numbers of large caliber blood vessels, the lumen of the vessels is irregular and many are obstructed, and there is less branching

craniofacial

abnormal craniofacial morphology ( J:82463 )

• Background Sensitivity: frequency of craniofacial defects is much lower (7.4%) on the predominantly FVB background than on mixed 50% 129P2/OlaHsd and 50% FVB background (27.5%)

abnormal pharyngeal arch morphology ( J:82463 )

• branchial arches are abnormal between E8-E13.5

nervous system

abnormal nervous system morphology ( J:82463 )

• Background Sensitivity: frequency of neural tube defects is much lower (7.4%) on the predominantly FVB background than on mixed 129P2/OlaHsd and FVB background (27.5%)

open neural tube ( J:82463 )

• neural tube is open between E8-13.5

kinked neural tube ( J:82463 )

• between E8-13.5, the neural tube is kinked

muscle

abnormal myogenesis ( J:82463 )

• the ratio of secondary/primary myotubes is slightly higher, indicating defective primary myogenesis

abnormal myotube morphology ( J:82463 )

• the reduction in secondary myotubes is due to the initial reduction in primary myotubes, not due to loss of secondary myotubes once they are formed

abnormal skeletal muscle morphology ( J:82463 )

• hindlimb muscles show a 2-fold increase in apoptosis at E16.5 and E17.5

decreased skeletal muscle fiber number ( J:82463 )

• reduction in muscle mass is due to a reduction in the number of both primary and secondary myotubes

decreased skeletal muscle mass ( J:82463 )

• skeletal muscle mass is reduced at E18.5

limbs/digits/tail

abnormal limb morphology ( J:82463 )

• between E8-13.5, the limbs are retarded or eccentricly located

behavior/neurological

abnormal posture ( J:82463 )

• posture at E18.5 is characterized by pronounced spinal curvature and downward facing head

homeostasis/metabolism

cyanosis ( J:82463 )

• 2 of 5 pups alive on P1 are purple, suggesting respiratory distress

skeleton

abnormal spine curvature ( J:82463 )

• posture at E18.5 is characterized by pronounced spinal curvature and downward facing head

cardiovascular system

cardiovascular system phenotype ( J:82463 )

N • Background Sensitivity: show no signs of hemorrhage on the predominately FVB background as is seen on the mixed 129P2/OlaHsd and FVB background

abnormal placental labyrinth vasculature morphology ( J:82463 )

• the placental labyrinth of the pale embryos contains reduced numbers of large caliber blood vessels, the lumen of the vessels is irregular and many are obstructed, and there is less branching

integument

pallor ( J:82463 )

• the subset of embryos that cease development between E13.5-E14.5 are very pale