Phenotypes Associated with This Genotype

Genotype
MGI:4830557

• Allelic Composition: Speg^tm1Mkap/Speg^tm1Mkap
• Genetic Background: either: B6.129S2-Speg^tm1Mkap or (involves: 129S2/SvPas * C57BL/6)

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

mortality/aging

postnatal lethality, complete penetrance ( J:163968 )

• Background Sensitivity: on a mixed 129S2/SvPas and C57BL/6 background, most mice die between P1 and P2 with few surviving to P21

prenatal lethality, complete penetrance ( J:163968 )

• on a congenic C57BL/6 background, no viable mice are observed postnatally

cardiovascular system

abnormal fetal cardiomyocyte morphology ( J:163968 )

• at E18.5, mice exhibit abnormal myocardium structural organization compared to in wild-type mice

• at E18.5, mice exhibit reduced myocyte nuclei per unit area of tissue compared to in wild-type mice

• at E18.5, myocyte size is increased compared to in wild-type mice

• at E18.5, cardiomyocytes of the myocardial layer contain vacuoles and less well-developed striations compared to in wild-type mice

• at E18.5, mice exhibit myofibril degeneration and sarcomere fragmentation unlike in wild-type mice

• however, rates of cardiomyocyte apoptosis are normal

abnormal coronary vessel morphology ( J:163968 )

• subepicardial vessels are dilated compared to in wild-type mice

enlarged heart ( J:163968 )

• at E18.5

increased heart weight ( J:163968 )

thin ventricular wall ( J:163968 )

abnormal epicardium morphology ( J:163968 )

• the epicardial through myocardial layers of the left ventricular free wall are thinner compared to in wild-type mice

dilated heart ( J:163968 )

• E16.5 and dramatic at E18.5

dilated heart left atrium ( J:163968 )

• at E18.5

dilated heart right atrium ( J:163968 )

• at E18.5

dilated heart ventricle ( J:163968 )

• at E18.5

decreased cardiac muscle contractility ( J:163968 )

• at E18.5, mice exhibit reduced left ventricular fractional shortening and ejection fraction compared with wild-type mice

respiratory system

small lung ( J:163968 )

• due to compression by the enlarged heart, mice exhibit reduced lung size compared with wild-type mice

• however, mice exhibit normal lung weight and inflation

muscle

decreased cardiac muscle contractility ( J:163968 )

• at E18.5, mice exhibit reduced left ventricular fractional shortening and ejection fraction compared with wild-type mice

growth/size/body

enlarged heart ( J:163968 )

• at E18.5

increased heart weight ( J:163968 )