Phenotypes associated with this allele

• Allele Symbol: Myb^tm1Jof
• Allele Name: targeted mutation 1, Jon Frampton
• Allele ID: MGI:2677048
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Myb^tm1Jof/Myb^tm1Jof	involves: 129/Sv * C57BL/6	MGI:2677331
ht2	Myb^tm1Jof/Myb^tm1Ssp	involves: 129/Sv * C57BL/6	MGI:2677339

Genotype
MGI:2677331

hm1

• Allelic Composition: Myb^tm1Jof/Myb^tm1Jof
• Genetic Background: involves: 129/Sv * C57BL/6

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

mortality/aging

premature death ( J:85344 )

• approximately 60% of all live births survive beyond 3 months

• deaths due to haematological deficiencies

growth/size/body

decreased body size ( J:85344 )

• pups undersized at birth

hematopoietic system

decreased thymocyte number ( J:85344 )

abnormal definitive hematopoiesis ( J:85344 )

abnormal erythropoiesis ( J:85344 )

• distribution of progenitor cells skewed toward earlier stage erythroblastic cells

abnormal B cell differentiation ( J:85344 )

• few B220 cells and those present were immature

abnormal T cell differentiation ( J:85344 )

abnormal double-negative T cell morphology ( J:85344 )

• little development past DN2 stage at E15

• by 6 days postnatal some differentiation past DN2/3 was evident

• by 3 months, thymocyte distribution and numbers near normal

increased megakaryocyte cell number ( J:85344 )

• increased numbers of megakaryocytes

abnormal myeloblast morphology/development ( J:85344 )

• absence of definable granulocytic progenitors

immune system

decreased thymocyte number ( J:85344 )

abnormal B cell differentiation ( J:85344 )

• few B220 cells and those present were immature

abnormal T cell differentiation ( J:85344 )

abnormal double-negative T cell morphology ( J:85344 )

• little development past DN2 stage at E15

• by 6 days postnatal some differentiation past DN2/3 was evident

• by 3 months, thymocyte distribution and numbers near normal

liver/biliary system

abnormal liver development ( J:85344 )

• obvious liver deficiencies at E14

• little or no reduction in liver cellularity at E15

• an apparent recovery of fetal liver haematopoiesis between E14 and E15

endocrine/exocrine glands

decreased thymocyte number ( J:85344 )

Genotype
MGI:2677339

ht2

• Allelic Composition: Myb^tm1Jof/Myb^tm1Ssp
• Genetic Background: involves: 129/Sv * C57BL/6

mortality/aging

lethality throughout fetal growth and development, complete penetrance ( J:85344 )

• embryos die around E16

hematopoietic system

decreased thymocyte number ( J:85344 )

abnormal definitive hematopoiesis ( J:85344 )

abnormal erythropoiesis ( J:85344 )

• progenitor cells were more immature for the most part

abnormal T cell differentiation ( J:85344 )

• cells seemed blocked at DN1 stage at E15

increased megakaryocyte cell number ( J:85344 )

• increased number of megakaryocytes until around E15 when numbers dropped off somewhat

abnormal myeloblast morphology/development ( J:85344 )

• absence of definable granulocytic progenitors

immune system

decreased thymocyte number ( J:85344 )

abnormal T cell differentiation ( J:85344 )

• cells seemed blocked at DN1 stage at E15

liver/biliary system

abnormal liver development ( J:85344 )

• small liver at E15

• anaemic

• conditions milder than when homozygous for Myb^tm1Ssp

endocrine/exocrine glands

decreased thymocyte number ( J:85344 )