Phenotypes associated with this allele

• Allele Symbol: Cr2^tm1Crr
• Allele Name: targeted mutation 1, Michael C Carroll
• Allele ID: MGI:1933715
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Cr2^tm1Crr/Cr2^tm1Crr	involves: 129S7/SvEvBrd	MGI:4453855
hm2	Cr2^tm1Crr/Cr2^tm1Crr	involves: 129S7/SvEvBrd * C57BL/6	MGI:2448261
hm3	Cr2^tm1Crr/Cr2^tm1Crr	involves: 129S7/SvEvBrd * C57BL/6J	MGI:3663105
cx4	Cr2^tm1Crr/Cr2^tm1Crr Ggta1^tm1Jbl/Ggta1^tm1Jbl	involves: 129S2/SvPas * 129S7/SvEvBrd	MGI:3694708

Genotype
MGI:4453855

hm1

• Allelic Composition: Cr2^tm1Crr/Cr2^tm1Crr
• Genetic Background: involves: 129S7/SvEvBrd

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

hematopoietic system

decreased follicular B cell number ( J:69477 )

• absolute numbers of follicular B cells are decreased

increased marginal zone B cell number ( J:69477 )

• absolute numbers of marginal zone B cells are increased

immune system

decreased follicular B cell number ( J:69477 )

• absolute numbers of follicular B cells are decreased

increased marginal zone B cell number ( J:69477 )

• absolute numbers of marginal zone B cells are increased

Genotype
MGI:2448261

hm2

• Allelic Composition: Cr2^tm1Crr/Cr2^tm1Crr
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6

mortality/aging

increased susceptibility to induced morbidity/mortality ( J:66111 )

• following cecal ligation and puncture

immune system

immune system phenotype ( J:31942 )

N • B cells show normal responses to LPS, IgM and CD40L

abnormal immune system morphology ( J:69452 )

• productive:nonproductive ratios of Ig heavy chain rearrangement are lower than in wild-type; somatic hypermutation is not reduced in mutants however

decreased neutrophil cell number ( J:66111 )

• in the peritoneal lavage following cecal ligation and puncture

decreased B cell number ( J:31942 )

abnormal B-1 B cell morphology ( J:31942 )

decreased B-1a cell number ( J:69452 )

• Cr2-deficient mice show a reduction in peritoneal B-1a (IgM+, CD5+) cells compared to wild-type (42% vs 71%)

abnormal spleen germinal center morphology ( J:31942 )

decreased spleen germinal center number ( J:31942 , J:69452 )

• 7 days after secondary challenge with phage, wild-type mice show >50% of splenic follicles containing germinal centers compared to many fewer in Cr2-deficient mice (J:31942)

• in Cr2-deficient mice, immunization with 5 ug of antigen results in 5-fold decrease in germinal center formation compared to wild-type receiving the same dose (J:69452)

decreased spleen germinal center size ( J:31942 )

• germinal centers exhibit cross-sectional areas about 10-fold less than in wild-type controls

abnormal humoral immune response ( J:31942 , J:69452 )

• mutants show defective humoral immune response to T dependent antigens (J:31942)

• after immunization with bacteriophage phiX174, Cr2-deficient mice fail to make normal primary or secondary humoral immune responses; IgG titers are reduced in mutants one week after immunization compared to controls (J:31942)

• bone marrow chimeras (wild-type bone marrow in Cr2-deficient hosts) have normal primary and secondary humoral responses after phage immunization (J:31942)

• Cr2-deficient mice have a weaker response to intrapertioneal injection with NP-CG compared to wild-type (J:69452)

decreased immunoglobulin level ( J:69452 )

• antibody responses decay twice as fast in Cr2-deficient mice as controls

decreased IgG level ( J:31942 , J:69452 )

• igG2a, 1gG2b and IgG3 levels are reduced in mutants compared to wild-type (J:31942)

• 5 ug NP-CG elicits a 4-fold weaker IgG1 response in Cr2-deficient mice; 50 ug NP-CG raises levels to half that of controls and a 10-fold increase in antigen dose results in a 7-fold increase in IgG1 response (J:69452)

• serum IgG1 levels are comparable in mutants and controls until day 16 post-immunization, then loss in mutants is accelerated (J:69452)

decreased IgG2a level ( J:31942 )

decreased IgG2b level ( J:31942 )

decreased IgG3 level ( J:31942 )

decreased IgM level ( J:69452 )

• 5 ug NP-CG elicits a 3-fold weaker IgM response in Cr2-deficient mice; a 10-fold increase in antigen results in a 3-fold increase in IgM

• after day 6 following immunization, serum IgM levels drop more rapidly in mutants compared to controls

decreased tumor necrosis factor secretion ( J:66111 )

• in the peritoneal lavage following cecal ligation and puncture

homeostasis/metabolism

increased susceptibility to injury ( J:66111 )

• following cecal ligation and puncture, mice exhibit decreased survival, decreased TNF levels in the peritoneal lavage, decreased neutrophil numbers in the peritoneal lavage, and increased bacteria in the peritoneal lavage compared with wild-type mice

hematopoietic system

decreased neutrophil cell number ( J:66111 )

• in the peritoneal lavage following cecal ligation and puncture

decreased B cell number ( J:31942 )

decreased B-1a cell number ( J:69452 )

• Cr2-deficient mice show a reduction in peritoneal B-1a (IgM+, CD5+) cells compared to wild-type (42% vs 71%)

abnormal B-1 B cell morphology ( J:31942 )

abnormal spleen germinal center morphology ( J:31942 )

decreased spleen germinal center number ( J:31942 , J:69452 )

• 7 days after secondary challenge with phage, wild-type mice show >50% of splenic follicles containing germinal centers compared to many fewer in Cr2-deficient mice (J:31942)

• in Cr2-deficient mice, immunization with 5 ug of antigen results in 5-fold decrease in germinal center formation compared to wild-type receiving the same dose (J:69452)

decreased spleen germinal center size ( J:31942 )

• germinal centers exhibit cross-sectional areas about 10-fold less than in wild-type controls

decreased immunoglobulin level ( J:69452 )

• antibody responses decay twice as fast in Cr2-deficient mice as controls

decreased IgG level ( J:31942 , J:69452 )

• igG2a, 1gG2b and IgG3 levels are reduced in mutants compared to wild-type (J:31942)

• 5 ug NP-CG elicits a 4-fold weaker IgG1 response in Cr2-deficient mice; 50 ug NP-CG raises levels to half that of controls and a 10-fold increase in antigen dose results in a 7-fold increase in IgG1 response (J:69452)

• serum IgG1 levels are comparable in mutants and controls until day 16 post-immunization, then loss in mutants is accelerated (J:69452)

decreased IgG2a level ( J:31942 )

decreased IgG2b level ( J:31942 )

decreased IgG3 level ( J:31942 )

decreased IgM level ( J:69452 )

• 5 ug NP-CG elicits a 3-fold weaker IgM response in Cr2-deficient mice; a 10-fold increase in antigen results in a 3-fold increase in IgM

• after day 6 following immunization, serum IgM levels drop more rapidly in mutants compared to controls

Genotype
MGI:3663105

hm3

• Allelic Composition: Cr2^tm1Crr/Cr2^tm1Crr
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6J

immune system

increased anti-double stranded DNA antibody level ( J:111811 )

• at 5-6 months of age, frequency of anti-dsDNA antibodies is significantly increased in female Cr2-deficient mice compared to B6.129-Igh^b controls

Genotype
MGI:3694708

cx4

• Allelic Composition: Cr2^tm1Crr/Cr2^tm1Crr; Ggta1^tm1Jbl/Ggta1^tm1Jbl
• Genetic Background: involves: 129S2/SvPas * 129S7/SvEvBrd

immune system

abnormal humoral immune response ( J:113488 )

• double mutants do not produce alpha-Gal-reactive natural antibodies; Ggta1-null and double mutants given anti alpha-Gal serumproduce similar levels of BSA-specific IgG antibodies after alpha-Gal immunization, indicating that complement receptors are not required to produce increased carrier immunogenicity

• elevated BSA immunogenicity in mutants is directly related to alpha-Gal specific antibodies