Phenotypes associated with this allele

• Allele Symbol: Tg(Cd8aCd8b)3Erob
• Allele Name: transgene insertion 3, Ellen Robey
• Allele ID: MGI:3056809
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
cx1	Tg(Cd8aCd8b)3Erob/0 Tg(TcraH-Y,TcrbH-Y)71Vbo/0	involves: C57BL/6 * DBA/2	MGI:3834902
tg2	Tg(Cd8aCd8b)3Erob/0	involves: C57BL/6 * DBA/2	MGI:3834901

Genotype
MGI:3834902

cx1

• Allelic Composition: Tg(Cd8aCd8b)3Erob/0; Tg(TcraH-Y,TcrbH-Y)71Vbo/0
• Genetic Background: involves: C57BL/6 * DBA/2

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

immune system

abnormal CD8-positive, alpha-beta T cell differentiation ( J:93004 )

• there is a 5-6 fold increase in the thymocyte population that is CD4^- CD8.2⁺ (i.e. positive for the endogenous CD8 complex)

• among thymocytes expressing the transgenic TCR, the skewing of the CD4:CD8 ratio is 1:50

• there is a 2-fold decrease in the number of CD4⁺ T cells that express the transgenic TCR compared to controls that do not carry the Tg(Cd8aCd8b)3Erob transgene

increased CD8-positive, alpha-beta T cell number ( J:93004 )

• the CD8 transgene further skews differentiation of T cells expressing the transgenic TCR into the CD8 T cell lineage

abnormal CD4-positive, alpha beta T cell morphology ( J:93004 )

• there is a 2-fold decrease in the number of CD4⁺ T cells that express the transgenic TCR compared to controls that do not carry the Tg(Cd8aCd8b)3Erob transgene

hematopoietic system

abnormal CD8-positive, alpha-beta T cell differentiation ( J:93004 )

• there is a 5-6 fold increase in the thymocyte population that is CD4^- CD8.2⁺ (i.e. positive for the endogenous CD8 complex)

• among thymocytes expressing the transgenic TCR, the skewing of the CD4:CD8 ratio is 1:50

• there is a 2-fold decrease in the number of CD4⁺ T cells that express the transgenic TCR compared to controls that do not carry the Tg(Cd8aCd8b)3Erob transgene

increased CD8-positive, alpha-beta T cell number ( J:93004 )

• the CD8 transgene further skews differentiation of T cells expressing the transgenic TCR into the CD8 T cell lineage

abnormal CD4-positive, alpha beta T cell morphology ( J:93004 )

• there is a 2-fold decrease in the number of CD4⁺ T cells that express the transgenic TCR compared to controls that do not carry the Tg(Cd8aCd8b)3Erob transgene

Genotype
MGI:3834901

tg2

• Allelic Composition: Tg(Cd8aCd8b)3Erob/0
• Genetic Background: involves: C57BL/6 * DBA/2

immune system

abnormal CD8-positive, alpha-beta T cell differentiation ( J:93004 )

• transgenic expression of the CD8 complex leads to almost all peripheral T cells expressing CD8 either alone as CD8⁺ T cells or as double positive CD4⁺CD8⁺ T cells

• endogenous expression of CD8 genes does not occur in CD4⁺CD8⁺ T cells but does occur in single positive CD8⁺ T cells

decreased double-negative T cell number ( J:93004 )

• the double negative population in the thymus is severely reduced due to expression of the transgenic CD8 complex

abnormal double-positive T cell morphology ( J:93004 )

• the single-positive CD4 T cell population in the periphery is replaced by a CD4⁺CD8⁺ population

• the double-positive population in the thymus is greatly enhanced

decreased CD4-positive, alpha-beta T cell number ( J:93004 )

• the single positive CD4 T cell population in the thymus and in the periphery is virtually absent due to transgenic expression of CD8

increased CD8-positive, alpha-beta T cell number ( J:93004 )

• almost all peripheral T cells express CD8 with over half also expressing CD4

hematopoietic system

abnormal CD8-positive, alpha-beta T cell differentiation ( J:93004 )

• transgenic expression of the CD8 complex leads to almost all peripheral T cells expressing CD8 either alone as CD8⁺ T cells or as double positive CD4⁺CD8⁺ T cells

• endogenous expression of CD8 genes does not occur in CD4⁺CD8⁺ T cells but does occur in single positive CD8⁺ T cells

decreased double-negative T cell number ( J:93004 )

• the double negative population in the thymus is severely reduced due to expression of the transgenic CD8 complex

abnormal double-positive T cell morphology ( J:93004 )

• the single-positive CD4 T cell population in the periphery is replaced by a CD4⁺CD8⁺ population

• the double-positive population in the thymus is greatly enhanced

decreased CD4-positive, alpha-beta T cell number ( J:93004 )

• the single positive CD4 T cell population in the thymus and in the periphery is virtually absent due to transgenic expression of CD8

increased CD8-positive, alpha-beta T cell number ( J:93004 )

• almost all peripheral T cells express CD8 with over half also expressing CD4