Phenotypes Associated with This Genotype

Genotype
MGI:3815407

• Allelic Composition: Ighm^tm1Msn/Ighm^tm1Msn
• Genetic Background: involves: 129S/SvEv

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

immune system

abnormal immature B cell morphology ( J:49405 )

• B cells in the bone marrow have reduced surface expression of IgM

abnormal mature B cell morphology ( J:49405 )

• splenic B cells have enhanced surface expression of IgM and decreased expression of IgD

abnormal B-1a B cell morphology ( J:49405 )

• B-1a B cell population is expanded in the peritoneum

• 65% of the B220⁺peritoneal cells are CD51 compared with 38% of B cells in controls

decreased IgG1 level ( J:49405 )

• after injection of a T cell-dependent antigen, mice have a 5-fold reduction in serum levels of antigen-specific IgG1 compared to controls

• the affinity of the IgG1 antibodies to antigen is lower than wild-type

• this defect could be rescued by the co-administration of IgM collected from the sera of non-immunized mice

• mice are also able to increase titers of IgG1 upon administration of a booster, to levels similar to that of wild-type mice

increased IgG3 level ( J:49405 )

• when mice are immunized with a T cell-independent antigen, serum levels of IgG3 are enhanced 3-fold compared to controls

• levels of other IgG levels are augmented also though specifics are not given

decreased IgM level ( J:49405 )

• IgM serum levels are undetectable

hematopoietic system

abnormal immature B cell morphology ( J:49405 )

• B cells in the bone marrow have reduced surface expression of IgM

abnormal mature B cell morphology ( J:49405 )

• splenic B cells have enhanced surface expression of IgM and decreased expression of IgD

abnormal B-1a B cell morphology ( J:49405 )

• B-1a B cell population is expanded in the peritoneum

• 65% of the B220⁺peritoneal cells are CD51 compared with 38% of B cells in controls

decreased IgG1 level ( J:49405 )

• after injection of a T cell-dependent antigen, mice have a 5-fold reduction in serum levels of antigen-specific IgG1 compared to controls

• the affinity of the IgG1 antibodies to antigen is lower than wild-type

• this defect could be rescued by the co-administration of IgM collected from the sera of non-immunized mice

• mice are also able to increase titers of IgG1 upon administration of a booster, to levels similar to that of wild-type mice

increased IgG3 level ( J:49405 )

• when mice are immunized with a T cell-independent antigen, serum levels of IgG3 are enhanced 3-fold compared to controls

• levels of other IgG levels are augmented also though specifics are not given

decreased IgM level ( J:49405 )

• IgM serum levels are undetectable