Phenotypes associated with this allele

• Allele Symbol: Ighm^tm1Che
• Allele Name: targeted mutation 1, Jianzhu Chen
• Allele ID: MGI:1934014
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ighm^tm1Che/Ighm^tm1Che	involves: 129 * C57BL/6	MGI:3834169
hm2	Ighm^tm1Che/Ighm^tm1Che	involves: 129S4/SvJae * C57BL/6	MGI:2179104

Genotype
MGI:3834169

hm1

• Allelic Composition: Ighm^tm1Che/Ighm^tm1Che
• Genetic Background: involves: 129 * C57BL/6

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

immune system

increased susceptibility to parasitic infection ( J:74568 )

• mice are able to clear a Giardia muris infection in a manner similar to wild-type mice

Genotype
MGI:2179104

hm2

• Allelic Composition: Ighm^tm1Che/Ighm^tm1Che
• Genetic Background: involves: 129S4/SvJae * C57BL/6

immune system

increased B-1 B cell number ( J:47425 )

• in spleen of mutants, a 2.6-fold increase in B-1 cells is detected

• in peritoneum, B-1 B cell numbers are elevated ~3-fold at 4 weeks of age through 12 months

abnormal spleen morphology ( J:125338 )

abnormal spleen white pulp morphology ( J:125338 )

abnormal metallophilic macrophage morphology ( J:125338 )

• after LPS challenge, marginal zone metallophilic -2+ (MOMA-2+) macrophages of the T and B cell zone fail to establish a ring of complement 3 (C3)-producing macrophages in the outer B cell zone close to the marginal zone

abnormal spleen B cell follicle morphology ( J:125338 )

• 72 hours after LPS challenge, spleen white pulp area continues to deteriorate; B cell follicles dissolve

abnormal spleen germinal center morphology ( J:47425 )

• 7 days after secondary immunization with suboptimal dose of T cell-dependent antigen NP-KLH, number and size of germinal centers in mutant spleens are reduced compared to controls; number is reduced ~4fold, but numbers are normal in mice immunized with 10 or 100 ug of antigen

• germinal center reactions are also impaired when 1 ug of NP-KLH antigen is used for immunization

abnormal spleen marginal zone morphology ( J:125338 )

• after 72 hours of LPS treatment, marginal zone is no longer structured; rings of 2F8+, ER-TR9+, and MOMA-1+ macrophages are not detectable

abnormal spleen periarteriolar lymphoid sheath morphology ( J:125338 )

• T cell zone shows severe destruction with disorganized B and T cells 72 hours after LPS treatment

abnormal immune system physiology ( J:47425 )

• germinal center reactions are impaired when 1 ug of NP-KLH antigen is used for immunization

• antibody affinity maturation is compromised in response to suboptimal doses of antigen (NP₅-BSA or NP₁₅-BSA)

abnormal B cell physiology ( J:47425 )

increased IgA level ( J:47425 )

• elevated in serum of mutants at young ages

decreased IgG1 level ( J:47425 )

• IgG1 levels after immunization with a suboptimal dose (<10 ug) of T cell-dependent antigen NP-KLH >100-fold lower in mutants

increased IgG2a level ( J:47425 )

• elevated in serum of mutants at 4 weeks, but difference disappears as mice mature

• treatment with the T cell independent antigen NP-Ficoll results in 3-4-fold increase in IgG2a at 7 and 14 days after immunization

decreased IgG2b level ( J:47425 )

• treatment with the T cell independent antigen NP-Ficoll reduced IgG2b levels after immunization

increased IgG3 level ( J:47425 )

• elevated in serum of mutants at 4 weeks, but difference disappears as mice mature

decreased IgM level ( J:47425 )

• IgM levels in serum are ~0.1 ug/ml compared to ~250 ug/ml in serum of wild-type controls; levels do not increase in mice up to 1 year in age

abnormal follicular dendritic cell antigen presentation ( J:47425 )

• antigen trapping on follicular dendritic cells (FDCs) in spleen germinal centers is impaired when 10 ug of NP-KLH antigen is used for immunization; no antigen trapping is detected on FDCs 12 days after immunization, even though titers of NP-specific IgG antibodies are comparable to wild-type

abnormal humoral immune response ( J:47425 )

• treatment with the T cell independent antigen NP-Ficoll results in 3-4-fold increase in IgG2a at 7 and 14 days after immunization

• IgG responses to T cell-dependent antigen NP-KLH are impaired at suboptimal antigen doses; at a suboptimal dose 7 days after immunization, IgG antibody levels are ~25-fold lower for primary and secondary responses relative to heterozygous controls

hematopoietic system

increased B-1 B cell number ( J:47425 )

• in spleen of mutants, a 2.6-fold increase in B-1 cells is detected

• in peritoneum, B-1 B cell numbers are elevated ~3-fold at 4 weeks of age through 12 months

abnormal spleen morphology ( J:125338 )

abnormal spleen white pulp morphology ( J:125338 )

abnormal metallophilic macrophage morphology ( J:125338 )

• after LPS challenge, marginal zone metallophilic -2+ (MOMA-2+) macrophages of the T and B cell zone fail to establish a ring of complement 3 (C3)-producing macrophages in the outer B cell zone close to the marginal zone

abnormal spleen B cell follicle morphology ( J:125338 )

• 72 hours after LPS challenge, spleen white pulp area continues to deteriorate; B cell follicles dissolve

abnormal spleen germinal center morphology ( J:47425 )

• 7 days after secondary immunization with suboptimal dose of T cell-dependent antigen NP-KLH, number and size of germinal centers in mutant spleens are reduced compared to controls; number is reduced ~4fold, but numbers are normal in mice immunized with 10 or 100 ug of antigen

• germinal center reactions are also impaired when 1 ug of NP-KLH antigen is used for immunization

abnormal spleen marginal zone morphology ( J:125338 )

• after 72 hours of LPS treatment, marginal zone is no longer structured; rings of 2F8+, ER-TR9+, and MOMA-1+ macrophages are not detectable

abnormal spleen periarteriolar lymphoid sheath morphology ( J:125338 )

• T cell zone shows severe destruction with disorganized B and T cells 72 hours after LPS treatment

abnormal B cell physiology ( J:47425 )

increased IgA level ( J:47425 )

• elevated in serum of mutants at young ages

decreased IgG1 level ( J:47425 )

• IgG1 levels after immunization with a suboptimal dose (<10 ug) of T cell-dependent antigen NP-KLH >100-fold lower in mutants

increased IgG2a level ( J:47425 )

• elevated in serum of mutants at 4 weeks, but difference disappears as mice mature

• treatment with the T cell independent antigen NP-Ficoll results in 3-4-fold increase in IgG2a at 7 and 14 days after immunization

decreased IgG2b level ( J:47425 )

• treatment with the T cell independent antigen NP-Ficoll reduced IgG2b levels after immunization

increased IgG3 level ( J:47425 )

• elevated in serum of mutants at 4 weeks, but difference disappears as mice mature

decreased IgM level ( J:47425 )

• IgM levels in serum are ~0.1 ug/ml compared to ~250 ug/ml in serum of wild-type controls; levels do not increase in mice up to 1 year in age