Phenotypes associated with this allele

• Allele Symbol: Nfib^tm1Hsch
• Allele Name: targeted mutation 1, Heinrich Schrewe
• Allele ID: MGI:2178748
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Nfib^tm1Hsch/Nfib^tm1Hsch	involves: 129S1/Sv * C57BL/6	MGI:2178810
ht2	Nfib^tm1Hsch/Nfib^+	involves: 129S1/Sv * C57BL/6	MGI:3653744

Genotype
MGI:2178810

hm1

• Allelic Composition: Nfib^tm1Hsch/Nfib^tm1Hsch
• Genetic Background: involves: 129S1/Sv * C57BL/6

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

mortality/aging

neonatal lethality, complete penetrance ( J:75698 )

• homozygotes are born alive but die within 15 min after birth due to respiratory failure

respiratory system

abnormal lung morphology ( J:75698 )

• at E18.5 and shortly after birth, mutant lungs appear developmentally immature with a gland-like appearance

abnormal lung development ( J:75698 )

• mutant lungs fail to develop beyond the late pseudoglandular or early canalicular stage

impaired branching involved in terminal bronchiole morphogenesis ( J:75698 )

• at E16.5, branching morphogenesis is slightly inhibited

• at E18.5, lobar branching from the primary bronchi is observed but further branching generates an undifferentiated primordial respiratory system

• at E18.5, the terminal buds are embedded within extensive mesenchyme and terminal sacs are absent

absent lung saccules ( J:75698 )

• at E18.5, terminal sacs are absent

abnormal pulmonary alveolus epithelial cell morphology ( J:75698 )

• at E18.5, mutant lungs exhibit undifferentiated type I and II pneumocytes

increased wet-to-dry lung weight ratio ( J:75698 )

• despite normal size and lobation, homozygous mutant lungs have a 40% higher wet weight than wild-type lungs; however, no difference in lung dry weight is observed

pulmonary hypoplasia ( J:75698 )

• newborn homozygotes display severe lung hypoplasia

atelectasis ( J:75698 )

• mutant lungs fail to float on water, indicating that they were never inflated with air

abnormal respiration ( J:75698 )

• at autopsy, all E18.5 mutant embryos and neonates contain air in their stomach and intestine, suggesting improper breathing

respiratory distress ( J:75698 )

• newborn homozygotes exhibit respiratory distress; however, no abnormalities are noted in the ribs, larynx, trachea, or other skeletal elements

respiratory failure ( J:75698 )

• newborn homozygotes make visible efforts to breathe but die of respiratory failure

vision/eye

failure of eyelid fusion ( J:75698 )

eyelids open at birth ( J:75698 )

• all homozygous mutant E18.5 embryos and neonates have open eyes due to failure of eyelid fusion

homeostasis/metabolism

cyanosis ( J:75698 )

• newborn homozygotes become cyanotic shortly after birth

Genotype
MGI:3653744

ht2

• Allelic Composition: Nfib^tm1Hsch/Nfib⁺
• Genetic Background: involves: 129S1/Sv * C57BL/6

respiratory system

abnormal lung development ( J:75698 )

• heterozygous mutant lungs are arrested at the late canalicular stage with only focal transition of tissue to the terminal sac stage

• the already developed terminal sacs protect heterozygotes from death due to asphyxia; as a result, all heterozygotes survive and appear overtly normal

• continued postnatal maturation of lungs proceeds and lung histology is indistinguishable from that of wild-type mice at 8 weeks postpartum

abnormal lung saccule morphology ( J:75698 )

• at E18.5, only a few terminal sacs surrounded by thick mesenchyme are observed

thick lung-associated mesenchyme ( J:75698 )

• at E18.6, heterozygous mutant lungs display a larger mesenchymal compartment and thicker interalveolar septae

increased wet-to-dry lung weight ratio ( J:75698 )

• heterozygous mutant lungs have a 16% higher wet weight than wild-type lungs, despite normal size and lobation; however, no difference in lung dry weight is observed

pulmonary hypoplasia ( J:75698 )

• at E18.5 and shortly after birth, heterozygous mutant lungs are slightly hypoplastic and premature relative to wild-type lungs