Phenotypes Associated with This Genotype

Genotype
MGI:4943703

• Allelic Composition: Dicer1^tm1Bdh/Dicer1^tm1Bdh; Shh^{tm1(EGFP/cre)Cjt}/Shh⁺
• Genetic Background: involves: 129

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

mortality/aging

perinatal lethality, complete penetrance ( J:106072 )

• mice die at birth

respiratory system

abnormal lung development ( J:106072 )

• at E12.5, fewer branches are observed and the distal tips of the newly formed branches appear dilated

• the number of dilated branching tips observed at E12.5 corresponds to the number of large, fluid-filled sacs seen at E15.5

• defective branching morphogenesis occurs prior to the increased cell death seen in the distal epithelium at E13.0

• at E11.75, expression of Fgf10 (a key gene involved in lung development) is already up-regulated and expanded in the mesenchyme of mutant lungs

abnormal lung epithelium morphology ( J:106072 )

• at E15.5, mutant lung epithelial cells form large, fluid-filled sacs within each lobe, indicating a severe branching defect

• at E15.5, the mutant epithelium is often detached from the mesenchyme, unlike in control lungs

• at E12.25, increased epithelial cell death is ectopically observed in the secondary bronchi of mutant lungs in addition to the normal pattern of cell death seen in the trachea and primary bronchi

• at E12.5 and E12.75, intense epithelial cell death is prolonged in the mutant trachea and bronchi, unlike in control and wild type lungs

• by E13.0, aberrant cell death is observed in the entire mutant lung epithelium, including the distal branching region, but not in the mesenchyme

small lung lobe ( J:106072 )

• after E13.5, each mutant lung lobe is proportionally smaller than that in control lungs

• however, each lobe maintains a normal shape, indicating a normal lobation pattern