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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Paxxem1Spj
endonuclease-mediated mutation 1, Stephen P Jackson
MGI:5822837
Summary 5 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Paxxem1Spj/Paxxem1Spj C57BL/6NTac-Paxxem1Spj MGI:5829786
cx2
Paxxem1Spj/Paxxem1Spj
Lig4tm1Fwa/Lig4tm1Fwa
involves: 129S6/SvEvTac * C57BL/6 * C57BL/6NTac MGI:5829792
cx3
Paxxem1Spj/Paxxem1Spj
Nhej1tm1Fwa/Nhej1tm1Fwa
involves: 129S6/SvEvTac * C57BL/6NTac MGI:5827971
cx4
Atmtm1Awb/Atmtm1Awb
Paxxem1Spj/Paxxem1Spj
involves: A/J * C57BL/6NTac MGI:5829795
cx5
Paxxem1Spj/Paxxem1Spj
Xrcc5tm1Nus/Xrcc5tm1Nus
involves: C57BL/6 * C57BL/6NTac MGI:5829790


Genotype
MGI:5829786
hm1
Allelic
Composition
Paxxem1Spj/Paxxem1Spj
Genetic
Background
C57BL/6NTac-Paxxem1Spj
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Paxxem1Spj mutation (0 available); any Paxx mutation (11 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• following exposure to 5 Gy of whole-body gamma radiation, mice (>12 weeks of age) show significantly increased lethality relative to wild-type controls, although this is not as dramatic as that observed in Atmtm1Awb homozygotes

immune system
N
• mice show no overt immunodeficiency and mount a normal humoral response upon immunization with purified fragment C of tetanus toxin relative to wild-type controls
• no defects in class switch recombination are observed
• mice exhibit a small increase in the number and percentage of mature B cells in the bone marrow
• significant reduction of B cell number in spleen
• mild reduction of transitional B cell number in spleen
• significant reduction of follicular B cell number in spleen
• significant reduction of T cell number in spleen
• however, T cell development in the thymus is normal
• significant reduction of CD4+ T cell number in spleen
• mild reduction of CD8+ T cell number in spleen
• mice show a significant reduction of total cell numbers in the spleen, but not in the thymus or bone marrow, relative to wild-type controls
• splenic cell reduction is mainly due to decreased B cell and T cell populations
• however, splenic marginal zone B cell numbers and NK cell numbers are normal

hematopoietic system
• mice exhibit a small increase in the number and percentage of mature B cells in the bone marrow
• significant reduction of B cell number in spleen
• mild reduction of transitional B cell number in spleen
• significant reduction of follicular B cell number in spleen
• significant reduction of T cell number in spleen
• however, T cell development in the thymus is normal
• significant reduction of CD4+ T cell number in spleen
• mild reduction of CD8+ T cell number in spleen
• mice show a significant reduction of total cell numbers in the spleen, but not in the thymus or bone marrow, relative to wild-type controls
• splenic cell reduction is mainly due to decreased B cell and T cell populations
• however, splenic marginal zone B cell numbers and NK cell numbers are normal

homeostasis/metabolism
• following exposure to 5 Gy of whole-body gamma radiation, mice (>12 weeks of age) show significantly increased lethality relative to wild-type controls, although this is not as dramatic as that observed in Atmtm1Awb homozygotes

cellular
N
• mice show no increased genomic instability, as determined by micronucleus formation

neoplasm
N
• mice show no increased tumor predisposition up to 400 days of age




Genotype
MGI:5829792
cx2
Allelic
Composition
Paxxem1Spj/Paxxem1Spj
Lig4tm1Fwa/Lig4tm1Fwa
Genetic
Background
involves: 129S6/SvEvTac * C57BL/6 * C57BL/6NTac
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lig4tm1Fwa mutation (2 available); any Lig4 mutation (46 available)
Paxxem1Spj mutation (0 available); any Paxx mutation (11 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• no mice are born, similar to single Lig4tm1Fwa homozygotes




Genotype
MGI:5827971
cx3
Allelic
Composition
Paxxem1Spj/Paxxem1Spj
Nhej1tm1Fwa/Nhej1tm1Fwa
Genetic
Background
involves: 129S6/SvEvTac * C57BL/6NTac
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Nhej1tm1Fwa mutation (0 available); any Nhej1 mutation (16 available)
Paxxem1Spj mutation (0 available); any Paxx mutation (11 available)
phenotype observed in females
phenotype observed in males
N normal phenotype

Small body size, absence of thymus, and small spleen in Paxxem1Spj/Paxxem1Spj Nhej1tm1Fwa/Nhej1tm1Fwa mice

mortality/aging
• although double homozygotes are present at normal Mendelian frequencies at E14.5, a significant number of them are dead by E18.5
• double homozygotes are severely underrepresented at 2 weeks of age, with only one mouse identified out of 25 expected

growth/size/body
• >50% of double mutant embryos are smaller than controls by E10.5
• however, somite numbers are normal at E10.5
• single born double mutant mouse is smaller than normal at birth
• single born double mutant mouse is smaller at 5 days of age and fails to thrive by 10 days of age
• body weight of single born double mutant mouse is significantly reduced at 10 days of age
• double mutant fetuses are smaller than controls at E14.5
• by E18.5, only a few double mutant fetuses are viable but show reduced body weight

immune system
• upon necropsy, single born double mutant mouse exhibited no thymus
• few double mutants surviving to E18.5 exhibit drastic involution of the thymus, unlike single Nhej1tm1Fwa homozygotes
• no lymphocytes are recovered upon red blood cell lysis
• upon necropsy, single born double mutant mouse exhibited a microspleen
• few double mutants surviving to E18.5 exhibit much smaller spleens than controls
• spleen weight of single born double mutant mouse is significantly reduced relative to body weight at 10 days of age
• single born double mutant mouse shows a significant decrease in splenic cell counts relative to body weight at 10 days of age

hematopoietic system
• upon necropsy, single born double mutant mouse exhibited no thymus
• few double mutants surviving to E18.5 exhibit drastic involution of the thymus, unlike single Nhej1tm1Fwa homozygotes
• no lymphocytes are recovered upon red blood cell lysis
• upon necropsy, single born double mutant mouse exhibited a microspleen
• few double mutants surviving to E18.5 exhibit much smaller spleens than controls
• spleen weight of single born double mutant mouse is significantly reduced relative to body weight at 10 days of age
• single born double mutant mouse shows a significant decrease in splenic cell counts relative to body weight at 10 days of age

cellular
• at E10.5 and E14.5, double mutants exhibit increased neural tube apoptosis, as shown by accumulation of cleaved caspase 3, especially in the cortical plate region of the cerebral cortex
• however, no increased apoptosis is observed in the skin, liver, heart or lung
• at E10.5 and E14.5, double mutants exhibit a significant increase in gammaH2AX-positive cells in the CNS (neural tube) relative to controls, indicating increased genomic instability
• mild genomic instability is also noted in the heart and skin

nervous system
• at E10.5 and E14.5, double mutants exhibit increased neural tube apoptosis, as shown by accumulation of cleaved caspase 3, especially in the cortical plate region of the cerebral cortex
• however, no increased apoptosis is observed in the skin, liver, heart or lung

embryo
• >50% of double mutant embryos are smaller than controls by E10.5
• however, somite numbers are normal at E10.5

endocrine/exocrine glands
• upon necropsy, single born double mutant mouse exhibited no thymus
• few double mutants surviving to E18.5 exhibit drastic involution of the thymus, unlike single Nhej1tm1Fwa homozygotes




Genotype
MGI:5829795
cx4
Allelic
Composition
Atmtm1Awb/Atmtm1Awb
Paxxem1Spj/Paxxem1Spj
Genetic
Background
involves: A/J * C57BL/6NTac
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Atmtm1Awb mutation (7 available); any Atm mutation (170 available)
Paxxem1Spj mutation (0 available); any Paxx mutation (11 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
N
• double homozygotes are born at the expected Mendelian frequencies and closely resemble single Atmtm1Awb homozygotes

immune system
• splenic B cells show no further defect in class switch recombination relative to that in single Atmtm1Awb homozygotes
• mice show a similar reduction of B cell number in spleen relative to single Atmtm1Awb homozygotes
• mice show a similar reduction of T cell number in spleen relative to single Atmtm1Awb homozygotes
• at 6-8 weeks of age, mice show a similar reduction of total cell numbers in spleen relative to single Atmtm1Awb homozygotes

hematopoietic system
• splenic B cells show no further defect in class switch recombination relative to that in single Atmtm1Awb homozygotes
• mice show a similar reduction of B cell number in spleen relative to single Atmtm1Awb homozygotes
• mice show a similar reduction of T cell number in spleen relative to single Atmtm1Awb homozygotes
• at 6-8 weeks of age, mice show a similar reduction of total cell numbers in spleen relative to single Atmtm1Awb homozygotes




Genotype
MGI:5829790
cx5
Allelic
Composition
Paxxem1Spj/Paxxem1Spj
Xrcc5tm1Nus/Xrcc5tm1Nus
Genetic
Background
involves: C57BL/6 * C57BL/6NTac
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Paxxem1Spj mutation (0 available); any Paxx mutation (11 available)
Xrcc5tm1Nus mutation (1 available); any Xrcc5 mutation (71 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• at 2 weeks of age, double homozygotes are significantly underrepresented relative to wild-type controls, but are found at ratios similar to those of single Xrcc5tm1Nus homozygotes
• no overt phenotypes are observed relative to single Xrcc5tm1Nus homozygotes





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last database update
12/17/2024
MGI 6.24
The Jackson Laboratory