Phenotypes associated with this allele

• Allele Symbol: Sftpb^tm1Jaw
• Allele Name: targeted mutation 1, Jeffrey A Whitsett
• Allele ID: MGI:2677852
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Sftpb^tm1Jaw/Sftpb^tm1Jaw	involves: 129S2/SvPas * Black Swiss	MGI:2677854
ht2	Sftpb^tm1Jaw/Sftpb^+	involves: 129S2/SvPas	MGI:4887986

Genotype
MGI:2677854

hm1

• Allelic Composition: Sftpb^tm1Jaw/Sftpb^tm1Jaw
• Genetic Background: involves: 129S2/SvPas * Black Swiss

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

mortality/aging

neonatal lethality, incomplete penetrance ( J:28289 )

• most homozygotes die within 20 min after birth due to respiratory failure

respiratory system

abnormal pulmonary alveolus morphology ( J:28289 )

• homozygotes exhibit absence of tubular myelin figures in the alveolar space, abnormal Golgi apparatus, and alveolar lipid aggregates composed of small vesicles and electron-dense proteinaceous material

abnormal type II pneumocyte morphology ( J:28289 )

• mutant type II pneumocytes lack fully formed lamellar bodies

absent alveolar lamellar bodies ( J:28289 )

• absence of fully formed lamellar bodies

atelectasis ( J:28289 )

• mutant lungs develop normally but do not fill with air, in spite of postnatal respiratory efforts

respiratory distress ( J:28289 )

• homozygotes exhibit lethal neonatal respiratory distress

respiratory failure ( J:28289 )

abnormal surfactant physiology ( J:28289 )

• homozygotes display aberrant routing, storage and function of surfactant phospholipids and proteins

abnormal surfactant composition ( J:28289 )

• surfactant contains an aberrant form of pro-SP-C, and there is a significant reduction in fully processed SP-C peptide in lung homogenates

abnormal surfactant secretion ( J:28289 )

• significant reduction in fully processed SP-C peptide in lung homogenates is observed

behavior/neurological

pup cannibalization ( J:28289 )

♀ • as a result of respiratory failure, dams occasionally cannibalize affected pups during the early postnatal period

homeostasis/metabolism

cyanosis ( J:28289 )

abnormal lipid homeostasis ( J:28289 )

• homozygotes display aberrant routing, storage and function of surfactant phospholipids and proteins, as evidenced by the presence of an aberrant form of pro-SP-C, and a significant reduction in fully processed SP-C peptide in lung homogenates

Genotype
MGI:4887986

ht2

• Allelic Composition: Sftpb^tm1Jaw/Sftpb⁺
• Genetic Background: involves: 129S2/SvPas

homeostasis/metabolism

increased susceptibility to injury ( J:59460 )

• after exposure to hyperoxia (95% O2 for 72 hrs), heterozygotes display a larger reduction in lung compliance and increased susceptibility to oxygen-induced lung injury, as shown by increased lung permeability and protein leakage into the alveolar space, pulmonary edema, hemorrhage and inflammation relative to wild-type controls

respiratory system

decreased total lung capacity ( J:59460 )

• after exposure to hyperoxia, total lung capacity (i.e. max. lung volume at an inflation pressure of 30 cm H2O) is significantly reduced in heterozygotes but not in wild-type controls

decreased lung compliance ( J:59460 )

• after exposure to room air, specific lung compliance in heterozygotes (12-20 wks of age) is significantly lower than that of wild-type controls

• after exposure to hyperoxia (95% O2 for 72 hrs), lung compliance is reduced by 46% in heterozygotes vs only 25% in wild-type controls

abnormal surfactant secretion ( J:59460 )

• after exposure to hyperoxia, surfactant B (SP-B) mRNA levels are increased 2-fold in both heterozygous and wild-type mice, but the levels in heterozygotes are half those in wild-type controls, and the concentration of immunoreactive SP-B and the ratio of SP-B to total protein in BALF is reduced by ~50% in heterozygotes relative to wild-type controls

• after exposure to hyperoxia, immunostaining for proSP-B and SP-B is virtually undetectable in heterozygous type II alveolar cells