Phenotypes associated with this allele

• Allele Symbol: Igh^tm1Leck
• Allele Name: targeted mutation 1, Laurel A Eckhardt
• Allele ID: MGI:3830835
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Igh^tm1Leck/Igh^tm1Leck	involves: 129P2/OlaHsd * C57BL/6	MGI:3830844
ht2	Igh^tm1Leck/Igh^+	involves: 129P2/OlaHsd * C57BL/6	MGI:3830846
cx3	Igh-J^tm1Cgn/Igh^tm1Leck	involves: 129P2/OlaHsd * C57BL/6	MGI:3830847

Genotype
MGI:3830844

hm1

• Allelic Composition: Igh^tm1Leck/Igh^tm1Leck
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

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

immune system

decreased B cell number ( J:144033 )

• total B cell number is reduced by half compared to wild-type mice

• the number of B cells is similar to Igh^tm2Cgn homozygotes indicating reduced number is due to the knock-in of the V heavy gene segments and not the lack of a Emu enhancer element

hematopoietic system

decreased B cell number ( J:144033 )

• total B cell number is reduced by half compared to wild-type mice

• the number of B cells is similar to Igh^tm2Cgn homozygotes indicating reduced number is due to the knock-in of the V heavy gene segments and not the lack of a Emu enhancer element

Genotype
MGI:3830846

ht2

• Allelic Composition: Igh^tm1Leck/Igh⁺
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

immune system

abnormal B cell morphology ( J:144033 )

• there is a break in allelic exclusion in 10% of IgM⁺ B cells in the bone marrow, 20% of 10% of IgM⁺ B cells, and 50% of IgM⁺ B cells in the peritoneum

abnormal immature B cell morphology ( J:144033 )

• 5% of immature B cells in the bone marrow have a break in allelic exclusion

abnormal immunoglobulin light chain V-J recombination ( J:144033 )

• the percentage of B cells expressing lambda light chain is about 3 times higher than in wild-type mice

• this increase in lamda-light chain expression only occurs among B cells demonstrating allelic exclusion (i.e. not expressing both the knock-in and endogenous heavy chain alleles)

abnormal mature B cell morphology ( J:144033 )

• 15% of mature B cells in the bone marrow, and 20% in the spleen, have a break in allelic exclusion

abnormal B-1a B cell morphology ( J:144033 )

• almost all B-1a B cells in the peritoneum express immunoglobulin heavy chains from both alleles (i.e. have a break in allelic exclusion)

hematopoietic system

abnormal B cell morphology ( J:144033 )

• there is a break in allelic exclusion in 10% of IgM⁺ B cells in the bone marrow, 20% of 10% of IgM⁺ B cells, and 50% of IgM⁺ B cells in the peritoneum

abnormal immature B cell morphology ( J:144033 )

• 5% of immature B cells in the bone marrow have a break in allelic exclusion

abnormal immunoglobulin light chain V-J recombination ( J:144033 )

• the percentage of B cells expressing lambda light chain is about 3 times higher than in wild-type mice

• this increase in lamda-light chain expression only occurs among B cells demonstrating allelic exclusion (i.e. not expressing both the knock-in and endogenous heavy chain alleles)

abnormal mature B cell morphology ( J:144033 )

• 15% of mature B cells in the bone marrow, and 20% in the spleen, have a break in allelic exclusion

abnormal B-1a B cell morphology ( J:144033 )

• almost all B-1a B cells in the peritoneum express immunoglobulin heavy chains from both alleles (i.e. have a break in allelic exclusion)

Genotype
MGI:3830847

cx3

• Allelic Composition: Igh-J^tm1Cgn/Igh^tm1Leck
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

immune system

abnormal immunoglobulin light chain V-J recombination ( J:144033 )

• the percentage of B cells expressing lambda light chain is about 4 times higher than in wild-type mice

hematopoietic system

abnormal immunoglobulin light chain V-J recombination ( J:144033 )

• the percentage of B cells expressing lambda light chain is about 4 times higher than in wild-type mice