About   Help   FAQ
Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Brca2tm1Mbn
targeted mutation 1, L Michelle Bennett
MGI:2387337
Summary 5 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Brca2tm1Mbn/Brca2tm1Mbn C.129P2-Brca2tm1Mbn MGI:3814401
hm2
Brca2tm1Mbn/Brca2tm1Mbn involves: 129P2/OlaHsd * 129S/SvEv MGI:3814400
ht3
Brca2tm1Mbn/Brca2+ B6.Cg-Brca2tm1Mbn ApcMin MGI:3814365
ht4
Brca2tm1Mbn/Brca2+ involves: 129P2/OlaHsd * 129S/SvEv MGI:3814399
cx5
ApcMin/Apc+
Brca2tm1Mbn/Brca2+
B6.Cg-Brca2tm1Mbn ApcMin MGI:3814367


Genotype
MGI:3814401
hm1
Allelic
Composition
Brca2tm1Mbn/Brca2tm1Mbn
Genetic
Background
C.129P2-Brca2tm1Mbn
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Brca2tm1Mbn mutation (0 available); any Brca2 mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• survival is extended to about E10.5 on a BALB/c genetic background, compared to E8.5 on a 129/B6 background

embryo
• at E8.5, embryos are smaller and show developmental delay compared to littermates; embryos resemble E6-E7-aged embryos at E8.5
• at E10.5, single surviving embryo displayed open cranial neural tube as in normal E8.5 embryos, but mutant embryo had completed turning and second branchial arch and heart were prominent

growth/size/body
• at E8.5, embryos are smaller and show developmental delay compared to littermates; embryos resemble E6-E7-aged embryos at E8.5

nervous system
• at E10.5, single surviving embryo displayed open cranial neural tube as in normal E8.5 embryos, but mutant embryo had completed turning and second branchial arch and heart were prominent




Genotype
MGI:3814400
hm2
Allelic
Composition
Brca2tm1Mbn/Brca2tm1Mbn
Genetic
Background
involves: 129P2/OlaHsd * 129S/SvEv
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Brca2tm1Mbn mutation (0 available); any Brca2 mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• embryos die before E8.5 and most are resorbed by this time




Genotype
MGI:3814365
ht3
Allelic
Composition
Brca2tm1Mbn/Brca2+
Genetic
Background
B6.Cg-Brca2tm1Mbn ApcMin
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Brca2tm1Mbn mutation (0 available); any Brca2 mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
integument
• females develop mammary tumors at an incidence rate of 23% with a mean tumor multiplicity rate of 0.3 +/- 0.5
• no males develop mammary tumors

growth/size/body
N
• body weight of mice at time of sacrifice does not differ significantly from Apc-heterozygous or wild-type animals; weight gain over experiment duration is similar to that of wild-type animals

reproductive system
N
• only observed in 1/10 ENU-treated males, similar to wild-type males (1/9)

neoplasm
• females develop mammary tumors at an incidence rate of 23% with a mean tumor multiplicity rate of 0.3 +/- 0.5
• no males develop mammary tumors

endocrine/exocrine glands
• females exhibit some adrenal hyperplasia, while none is observed in males
• females develop mammary tumors at an incidence rate of 23% with a mean tumor multiplicity rate of 0.3 +/- 0.5
• no males develop mammary tumors

Mouse Models of Human Disease
OMIM ID Ref(s)
Breast Cancer 114480 J:67445




Genotype
MGI:3814399
ht4
Allelic
Composition
Brca2tm1Mbn/Brca2+
Genetic
Background
involves: 129P2/OlaHsd * 129S/SvEv
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Brca2tm1Mbn mutation (0 available); any Brca2 mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• virgin females display no increased incidence of spontaneous tumors relative to wild-type littermates up to 2 years of age




Genotype
MGI:3814367
cx5
Allelic
Composition
ApcMin/Apc+
Brca2tm1Mbn/Brca2+
Genetic
Background
B6.Cg-Brca2tm1Mbn ApcMin
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
ApcMin mutation (8 available); any Apc mutation (85 available)
Brca2tm1Mbn mutation (0 available); any Brca2 mutation (60 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
growth/size/body
N
• body weight of mice at time of sacrifice does not differ significantly from Apc-heterozygous, Brca2-heterozygous, or wild-type animals

reproductive system
N
• only observed in 1/8 ENU-treated males, similar to wild-type males (1/9)
• absent in 22% of ENU-treated females
• remaining follicles are degenerating in ENU-treated females
• arrested follicular development is 6-fold more prevalent compared to ENU-treated Brca2-deficient mice
• complete loss of follicles (ovarian atrophy) is observed in about 25% of ENU-treated mutants, whereas almost no incidence is observed in ENU-treated wild-type or Brca2-mutant females
• observed in ENU-treated females displaying ovarian failure (atrophy); endometrium and myometrium appear immature
• reduced in thickness and lined with vacuolated cells indicative of anestrus in ENU-treated females

neoplasm
• by 65 days after ENU treatment, 100% of females develop mammary tumors with a multiplicity of 7.2 +/- 2.7, whereas only 7% of wild-type females develop tumors
• males develop tumors at a very low incidence and with a tumor multiplicity of 0.2 +/- 0.3, whereas no wild-type or Brca2-heterozygous males developed mammary tumors
• tumors in male and female mice are adenoacanthomas, characterized by undifferentiated acini and tubules with centrally confined squamous cells and keratin; most tumors contain proportions of adenomatous and squamous cell types
• tumors with predominantly squamous differentiation, moderate to marked inflammation in and around tumors is observed, with areas of fibrosis; in some cases, squamous component becomes cystic and is filled with keratinous debris
• invasion or metastases into the mammary lymph nodes was not observed during time course of study
• multiple intestinal tumors are observed in ENU-treated mice

endocrine/exocrine glands
• in ENU treated mice, male mammary ducts are elongated and in most males have extended to the lymph node of the fourth mammary gland, whereas wild-type and Brca2-heterozygous males are born with a small mammary gland rudiment, which grows no further, and no nipple
• no differences are observed in branching of female mammary glands among genotypes or wild-type females
• by 65 days after ENU treatment, 100% of females develop mammary tumors with a multiplicity of 7.2 +/- 2.7, whereas only 7% of wild-type females develop tumors
• males develop tumors at a very low incidence and with a tumor multiplicity of 0.2 +/- 0.3, whereas no wild-type or Brca2-heterozygous males developed mammary tumors
• tumors in male and female mice are adenoacanthomas, characterized by undifferentiated acini and tubules with centrally confined squamous cells and keratin; most tumors contain proportions of adenomatous and squamous cell types
• tumors with predominantly squamous differentiation, moderate to marked inflammation in and around tumors is observed, with areas of fibrosis; in some cases, squamous component becomes cystic and is filled with keratinous debris
• invasion or metastases into the mammary lymph nodes was not observed during time course of study
• absent in 22% of ENU-treated females
• remaining follicles are degenerating in ENU-treated females
• arrested follicular development is 6-fold more prevalent compared to ENU-treated Brca2-deficient mice
• complete loss of follicles (ovarian atrophy) is observed in about 25% of ENU-treated mutants, whereas almost no incidence is observed in ENU-treated wild-type or Brca2-mutant females

homeostasis/metabolism

integument
• in ENU treated mice, male mammary ducts are elongated and in most males have extended to the lymph node of the fourth mammary gland, whereas wild-type and Brca2-heterozygous males are born with a small mammary gland rudiment, which grows no further, and no nipple
• no differences are observed in branching of female mammary glands among genotypes or wild-type females
• by 65 days after ENU treatment, 100% of females develop mammary tumors with a multiplicity of 7.2 +/- 2.7, whereas only 7% of wild-type females develop tumors
• males develop tumors at a very low incidence and with a tumor multiplicity of 0.2 +/- 0.3, whereas no wild-type or Brca2-heterozygous males developed mammary tumors
• tumors in male and female mice are adenoacanthomas, characterized by undifferentiated acini and tubules with centrally confined squamous cells and keratin; most tumors contain proportions of adenomatous and squamous cell types
• tumors with predominantly squamous differentiation, moderate to marked inflammation in and around tumors is observed, with areas of fibrosis; in some cases, squamous component becomes cystic and is filled with keratinous debris
• invasion or metastases into the mammary lymph nodes was not observed during time course of study

Mouse Models of Human Disease
OMIM ID Ref(s)
Breast Cancer 114480 J:67445





Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Tumor Biology (MTB), Gene Ontology (GO), MouseCyc
Citing These Resources
Funding Information
Warranty Disclaimer & Copyright Notice
Send questions and comments to User Support.
last database update
07/12/2016
MGI 6.04
The Jackson Laboratory