Phenotypes associated with this allele

• Allele Symbol: Mb^tm1Jsc
• Allele Name: targeted mutation 1, Jurgen Schrader
• Allele ID: MGI:2159004
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Mb^tm1Jsc/Mb^tm1Jsc	involves: 129S1/Sv * 129X1/SvJ * NMRI	MGI:3623501

Genotype
MGI:3623501

hm1

• Allelic Composition: Mb^tm1Jsc/Mb^tm1Jsc
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * NMRI

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

cardiovascular system

increased capillary density ( J:57481 )

• mutant hearts display a 30% increase in capillary density relative to wild-type hearts (4,140 140 mm^-2 vs 3,111 400 mm^-2), resulting in a reduction of mean capillary distance by 2.5 m

• however, no significant differences in total mitochondrial density, mitochondrial distribution or total cardiac cytochrome c oxidase activity are observed

abnormal heart morphology ( J:57481 )

• isolated perfused hearts from homozygous mutant mice display a yellow color in contrast to the pale red color of wild-type hearts

increased coronary flow rate ( J:57481 )

• isolated perfused hearts from mutant mice show no significant differences in left ventricular pressure, dP/dtmax, dP/dtmin, tissue ATP levels, phosphocreatine or myocardial oxygen consumption (MVO2) under basal conditions or after maximal beta-adrenergic stimulation (200 nM dobutamine) relative to wild-type hearts

• however, mutant hearts display a ~30% increase in coronary flow under basal conditions and a >25% increase under stimulation with 50 and 200 nM dobutamine

• maximal coronary flow response elicited by intracoronary infusion of adenosine or as peak flow of reactive hyperemia after coronary occlusion is elevated by ~25% in mutant hearts

• in addition, mutant hearts display higher coronary venous PO2 (V-PO2) values: under basal conditions, mutant V-PO2 is 123 mmHg and falls to 67 and 38 mmHg at 50 and 200 nM dobutamine, respectively, whereas wild-type V-PO2 is 88 mmHg and falls to 38 and 12.5 mmHg, respectively

hematopoietic system

increased hematocrit ( J:57481 )

• homozygotes exhibit elevated hematocrits relative to wild-type mice

increased hemoglobin content ( J:57481 )

• homozygotes exhibit slightly but significantly increased hemoglobin concentrations relative to wild-type mice (14.4 0.5 g/dl vs 13.3 0.6 g/dl, respectively)

• however, no significant differences in hemoglobin:hematocrit ratio are observed

homeostasis/metabolism

abnormal oxygen level ( J:57481 )

• homozygotes exhibit activation of compensatory mechanisms all of which tend to steepen the oxygen gradient from the capillary to the mitochondria and thereby augment the flux of oxygen