Phenotypes associated with this allele

• Allele Symbol: Mybl1^tm1Epr
• Allele Name: targeted mutation 1, E Premkumar Reddy
• Allele ID: MGI:2447613
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Mybl1^tm1Epr/Mybl1^tm1Epr	involves: 129 * C57BL/6	MGI:2664241
hm2	Mybl1^tm1Epr/Mybl1^tm1Epr	Not Specified	MGI:2664240
ht3	Mybl1^repro9/Mybl1^tm1Epr	involves: C3HeB/FeJ * C57BL/6J	MGI:5292391

Genotype
MGI:2664241

hm1

• Allelic Composition: Mybl1^tm1Epr/Mybl1^tm1Epr
• Genetic Background: involves: 129 * C57BL/6

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

immune system

decreased B cell number ( J:67604 )

• ~2-fold reduction in percentage of splenic B cells (B220⁺) relative to wild-type controls; however, proportions of splenic immature and mature B cells are normal

• normal B cell development in the bone marrow, as shown by normal numbers of pro-B, pre-B, immature, and mature B cell subpopulations

increased spleen red pulp amount ( J:67604 )

• expanded red pulp areas

small spleen ( J:67604 )

• reduced average spleen size

spleen hypoplasia ( J:67604 )

• mild splenic hypoplasia involving all areas of the white pulp

abnormal spleen B cell follicle morphology ( J:67604 )

• mildly hypoplastic

decreased spleen germinal center number ( J:67604 )

• the number of "spontaneous" GCs in naive mutant spleens is severalfold lower than that in wild-type controls

abnormal spleen marginal zone morphology ( J:67604 )

• mildly hypoplastic

abnormal humoral immune response ( J:67604 )

• impaired primary serum antibody response, following immunization with the T cell-dependent antigen NP-CGG in alum, as shown by reduced primary serum levels of IgG3 and IgG1 (the major isotypes in this response), as well as IgG2a; however, the early primary IgM response and secondary anti-NP serum Ab responses are normal

• normal germinal center reaction following immunization with the T cell-dependent antigen NP-CGG

• normal development of B cell memory, as shown by normal V gene somatic hypermutation and Ag affinity-based positive selection during the anti-NP response

• normal rate of B cell proliferation following in vitro stimulation with LPS, anti-CD40, or anti-IgM

• normal H chain class switching by B cells following in vitro stimulation with LPS or LPS and IL-4

decreased IgG1 level ( J:67604 )

• reduced primary serum levels of IgG1 following immunization with the T cell-dependent antigen NP-CGG

decreased IgG2a level ( J:67604 )

• reduced primary serum levels of IgG2a following immunization with the T cell-dependent antigen NP-CGG

decreased IgG3 level ( J:67604 )

• reduced primary serum levels of IgG3 following immunization with the T cell-dependent antigen NP-CGG

hematopoietic system

decreased B cell number ( J:67604 )

• ~2-fold reduction in percentage of splenic B cells (B220⁺) relative to wild-type controls; however, proportions of splenic immature and mature B cells are normal

• normal B cell development in the bone marrow, as shown by normal numbers of pro-B, pre-B, immature, and mature B cell subpopulations

increased spleen red pulp amount ( J:67604 )

• expanded red pulp areas

small spleen ( J:67604 )

• reduced average spleen size

spleen hypoplasia ( J:67604 )

• mild splenic hypoplasia involving all areas of the white pulp

abnormal spleen B cell follicle morphology ( J:67604 )

• mildly hypoplastic

decreased spleen germinal center number ( J:67604 )

• the number of "spontaneous" GCs in naive mutant spleens is severalfold lower than that in wild-type controls

abnormal spleen marginal zone morphology ( J:67604 )

• mildly hypoplastic

decreased IgG1 level ( J:67604 )

• reduced primary serum levels of IgG1 following immunization with the T cell-dependent antigen NP-CGG

decreased IgG2a level ( J:67604 )

• reduced primary serum levels of IgG2a following immunization with the T cell-dependent antigen NP-CGG

decreased IgG3 level ( J:67604 )

• reduced primary serum levels of IgG3 following immunization with the T cell-dependent antigen NP-CGG

Genotype
MGI:2664240

hm2

• Allelic Composition: Mybl1^tm1Epr/Mybl1^tm1Epr
• Genetic Background: Not Specified

reproductive system

abnormal spermatocyte morphology ( J:39632 )

♂ • variable degeneration of most pachytene primary spermatocytes, ranging from early nuclear changes to advanced stages of cellular breakdown

decreased male germ cell number ( J:39632 )

♂ • absence of post-meiotic spermatids and spermatozoa

azoospermia ( J:39632 , J:175539 )

♂ • complete absence of spermatozoa (J:39632)

♂ • however, serum testosterone levels were normal (J:39632)

♂ • mice lack postmeiotic spermatids (J:175539)

abnormal synaptonemal complex ( J:175539 )

• some spermatocytes fail to establish or maintain synapsis of homologous autosomes

increased male germ cell apoptosis ( J:39632 )

♂ • increased spermatocyte apoptosis, as shown by TUNEL staining

abnormal mammary gland growth during pregnancy ( J:39632 )

♀ • impaired mammary gland epithelial expansion during pregnancy

abnormal Sertoli cell morphology ( J:39632 )

♂ • vacuolization of Sertoli cell cytoplasm

small seminiferous tubules ( J:39632 )

♂ • slight reduction in size; however, number of tubules per testis was normal

small testis ( J:39632 )

♂ • ~75% reduction in testis size, irrespective of age

decreased testis weight ( J:39632 )

♂ • ~75% reduction in testis weight, irrespective of age

arrest of spermatogenesis ( J:39632 )

♂

arrest of male meiosis ( J:39632 , J:175539 )

♂ • germ cells enter meiotic prophase and arrest at pachytene (J:39632)

♂ • before the mid-pachytene transition (J:175539)

male infertility ( J:39632 , J:175539 )

♂ (J:39632)

♂ (J:175539)

growth/size/body

decreased body size ( J:39632 )

• size discrepancy became less pronounced with age

• mice eventually attained a nearly normal body size (approximately 90% for females and 70% for males)

postnatal growth retardation ( J:39632 )

• mice were indistinguishable from littermates at birth but lagged in growth during the first few weeks of life

endocrine/exocrine glands

abnormal mammary gland growth during lactation ( J:39632 )

♀ • >60% reduction in proliferation of ductal cells and incomplete formation of alveolar structures at 2 days after pup delivery relative to lactating wild-type controls

abnormal mammary gland growth during pregnancy ( J:39632 )

♀ • impaired mammary gland epithelial expansion during pregnancy

abnormal mammary gland epithelium morphology ( J:39632 )

♀ • abundant fat cells in mammary gland epithelium at 2 days after pup delivery versus rare fat cells in lactating wild-type controls

abnormal Sertoli cell morphology ( J:39632 )

♂ • vacuolization of Sertoli cell cytoplasm

small seminiferous tubules ( J:39632 )

♂ • slight reduction in size; however, number of tubules per testis was normal

small testis ( J:39632 )

♂ • ~75% reduction in testis size, irrespective of age

decreased testis weight ( J:39632 )

♂ • ~75% reduction in testis weight, irrespective of age

behavior/neurological

hunched posture ( J:39632 )

• hunched posture of pups became less pronounced as mice matured (4 months of age)

abnormal nursing ( J:39632 )

♀ • females were unable to nurse newborn offspring

integument

abnormal mammary gland growth during lactation ( J:39632 )

♀ • >60% reduction in proliferation of ductal cells and incomplete formation of alveolar structures at 2 days after pup delivery relative to lactating wild-type controls

abnormal mammary gland growth during pregnancy ( J:39632 )

♀ • impaired mammary gland epithelial expansion during pregnancy

abnormal mammary gland epithelium morphology ( J:39632 )

♀ • abundant fat cells in mammary gland epithelium at 2 days after pup delivery versus rare fat cells in lactating wild-type controls

wrinkled skin ( J:39632 )

• wrinkled appearance of pups became less pronounced as mice matured (4 months of age)

cellular

abnormal spermatocyte morphology ( J:39632 )

♂ • variable degeneration of most pachytene primary spermatocytes, ranging from early nuclear changes to advanced stages of cellular breakdown

decreased male germ cell number ( J:39632 )

♂ • absence of post-meiotic spermatids and spermatozoa

azoospermia ( J:39632 , J:175539 )

♂ • complete absence of spermatozoa (J:39632)

♂ • however, serum testosterone levels were normal (J:39632)

♂ • mice lack postmeiotic spermatids (J:175539)

arrest of male meiosis ( J:39632 , J:175539 )

♂ • germ cells enter meiotic prophase and arrest at pachytene (J:39632)

♂ • before the mid-pachytene transition (J:175539)

abnormal synaptonemal complex ( J:175539 )

• some spermatocytes fail to establish or maintain synapsis of homologous autosomes

increased male germ cell apoptosis ( J:39632 )

♂ • increased spermatocyte apoptosis, as shown by TUNEL staining

Genotype
MGI:5292391

ht3

• Allelic Composition: Mybl1^repro9/Mybl1^tm1Epr
• Genetic Background: involves: C3HeB/FeJ * C57BL/6J

reproductive system

azoospermia ( J:175539 )

♂ • mice lack postmeiotic spermatids

arrest of male meiosis ( J:175539 )

♂ • before the mid-pachytene transition

abnormal synaptonemal complex ( J:175539 )

• some spermatocytes fail to establish or maintain synapsis of homologous autosomes

abnormal testis morphology ( J:175539 )

♂ • some spermatocytes fail to establish or maintain synapsis of homologous autosomes

male infertility ( J:175539 )

♂

endocrine/exocrine glands

abnormal testis morphology ( J:175539 )

♂ • some spermatocytes fail to establish or maintain synapsis of homologous autosomes

cellular

azoospermia ( J:175539 )

♂ • mice lack postmeiotic spermatids

arrest of male meiosis ( J:175539 )

♂ • before the mid-pachytene transition

abnormal synaptonemal complex ( J:175539 )

• some spermatocytes fail to establish or maintain synapsis of homologous autosomes