Phenotypes Associated with This Genotype

Genotype
MGI:2667178

• Allelic Composition: Ikzf1^tm1Kast/Ikzf1^tm1Kast
• Genetic Background: involves: 129S2/SvPas

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

immune system

abnormal B cell differentiation ( J:82813 )

• partial block at the pro-B cell stage of differentiation as indicated by an unusual pattern of cell surface marker expression and decreased transcript levels for TdT, Rag1, Rag2 and lambda5

• fewer cells differentiate and differentiation of proB cells into mature IgM+ B cells is delayed

decreased B cell number ( J:82813 )

• B220+ B cells are absent in the fetal liver but are seen in the adult bone marrow

• B220+ B cell numbers in the adult bone marrow are reduced

• fewer B cell precursors in the bone marrow as indicated by the reduction in pre-proB (B220⁺CD43^hiCD24^loBP- 1^lo) cells and the reduction in number of cells responding to IL-7 in vitro

• however, proportion of immature versus mature B cells in the spleen appear normal

decreased B-1a cell number ( J:82813 )

• reduction in level of B-1a cells in the peritoneal cavity

decreased B-1b cell number ( J:82813 )

• reduction in level of B-1b cells in the peritoneal cavity

decreased spleen germinal center number ( J:82813 )

• B cells form fewer germinal centers in the spleen in response to antigenic stimulation, indicating that B cells are less able to respond to antigen even though they are more sensitive to activation

abnormal B cell activation ( J:82813 )

• splenic B cells have a lower threshold of activation and are more responsive to stimulation

decreased B cell proliferation ( J:82813 )

• IL-7-dependent proliferation of stromal cell-independent B cell progenitors is impaired

decreased IgG3 level ( J:82813 )

• low to non-existant levels of IgG3

• however, levels of IgM, IgG1, IgG2a and IgG2b are normal

hematopoietic system

abnormal B cell differentiation ( J:82813 )

• partial block at the pro-B cell stage of differentiation as indicated by an unusual pattern of cell surface marker expression and decreased transcript levels for TdT, Rag1, Rag2 and lambda5

• fewer cells differentiate and differentiation of proB cells into mature IgM+ B cells is delayed

decreased B cell number ( J:82813 )

• B220+ B cells are absent in the fetal liver but are seen in the adult bone marrow

• B220+ B cell numbers in the adult bone marrow are reduced

• fewer B cell precursors in the bone marrow as indicated by the reduction in pre-proB (B220⁺CD43^hiCD24^loBP- 1^lo) cells and the reduction in number of cells responding to IL-7 in vitro

• however, proportion of immature versus mature B cells in the spleen appear normal

decreased B-1a cell number ( J:82813 )

• reduction in level of B-1a cells in the peritoneal cavity

decreased B-1b cell number ( J:82813 )

• reduction in level of B-1b cells in the peritoneal cavity

decreased spleen germinal center number ( J:82813 )

• B cells form fewer germinal centers in the spleen in response to antigenic stimulation, indicating that B cells are less able to respond to antigen even though they are more sensitive to activation

abnormal B cell activation ( J:82813 )

• splenic B cells have a lower threshold of activation and are more responsive to stimulation

decreased B cell proliferation ( J:82813 )

• IL-7-dependent proliferation of stromal cell-independent B cell progenitors is impaired

decreased IgG3 level ( J:82813 )

• low to non-existant levels of IgG3

• however, levels of IgM, IgG1, IgG2a and IgG2b are normal

cellular

decreased B cell proliferation ( J:82813 )

• IL-7-dependent proliferation of stromal cell-independent B cell progenitors is impaired