Analysis Tools
mortality/aging
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• on a mixed 129 x B6 background, homozygotes are born at the expected Mendelian frequency and survive to adulthood
• Background Sensitivity: on a congenic B6 background, homozygotes show a step-wise decline in survival, with death occurring both during late embryogenesis (between E15.5 and E18.5) and in the first 2 postnatal weeks
• Background Sensitivity: the lethality observed on a congenic B6 background is completely rescued by a single outcross with CD1 mice
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cellular
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• despite defects in many seminiferous tubules, some homozygotes produce sperm; however, sperm production is greatly reduced
• only a few spermatogonia survive in severely affected testes
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growth/size/body
kidney cyst
(
J:50844
)
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• focal cystic dilation is sometimes noted in adult kidneys along with signs of atrophy of surrounding renal tubules and glomeruli
• a lack of vascularization is also observed in mutant kidneys
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• as early as P6, small cysts are noted within the developing cortex
• number and size of epithelial kidney cortex cysts increase with age
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• at ~2 weeks of age, homozygotes appear runted
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• adult homozygotes weigh ~20%-25% less than wild-type littermates
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reproductive system
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• despite defects in many seminiferous tubules, some homozygotes produce sperm; however, sperm production is greatly reduced
• only a few spermatogonia survive in severely affected testes
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• male homozygotes show late-stage defects in the differentiation and/or maintenance of the testes
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• at 1 month of age, the diameters of mutant seminiferous tubules and numbers of cells within tubules are abnormally reduced
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• adult male homozygotes display degenerating seminiferous tubules with a few spermatogonia; often only Sertoli cells remain
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small testis
(
J:50844
)
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• although initially normal in terms of size and morphology, mutant testes become abnormally small by 4 weeks of age
• a lack of vascularization is also observed in mutant testes
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• by 4 weeks of age, mutant testes are only 15%-50% of wild-type testis weight
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• in adult females, the external vaginal opening is often constricted
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• in a few adult females, the external vaginal opening is completely fused
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• male homozygotes display defective differentiating cells from the primary spermatocyte stage onward
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• female homozygotes show reduced fertility primarily due to structural defects in the urogenital tract
• however, no apparent defects are observed in oogenesis
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• although sperm production is markedly diminished, male homozygotes are not entirely sterile
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renal/urinary system
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• homozygotes show late-stage defects in the differentiation and/or maintenance of the kidneys
• interestingly, whereas hair defects are more pronounced in males, urogenital defects occur predominantly in females
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kidney cyst
(
J:50844
)
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• focal cystic dilation is sometimes noted in adult kidneys along with signs of atrophy of surrounding renal tubules and glomeruli
• a lack of vascularization is also observed in mutant kidneys
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• as early as P6, small cysts are noted within the developing cortex
• number and size of epithelial kidney cortex cysts increase with age
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endocrine/exocrine glands
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• male homozygotes show late-stage defects in the differentiation and/or maintenance of the testes
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• at 1 month of age, the diameters of mutant seminiferous tubules and numbers of cells within tubules are abnormally reduced
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• adult male homozygotes display degenerating seminiferous tubules with a few spermatogonia; often only Sertoli cells remain
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small testis
(
J:50844
)
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• although initially normal in terms of size and morphology, mutant testes become abnormally small by 4 weeks of age
• a lack of vascularization is also observed in mutant testes
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• by 4 weeks of age, mutant testes are only 15%-50% of wild-type testis weight
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integument
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• at P8, occasional auchene hairs are defective
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• at P8, occasional awl hairs are defective
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ruffled hair
(
J:50844
)
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• at ~2 weeks of age, homozygotes display a visibly fuzzy, ruffled hair coat; more pronounced in males, but seen in both sexes
• however, newborn homozygotes show a largely unaffected skin morphology with no obvious biochemical defects in epidermal and hair-specific markers
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• as early as P8, 16% of guard hairs display signs of separation or splitting
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• as early as P8, a number of hairs show kinks and/or intercellular splits within or along the hair shafts
• hair defects appear to arise from a structural weakness or mild changes in the intercellular interactions within the hair shaft
• however, no ultrastructural changes within cells of the inner root sheath, outer root sheath, cuticle, cortex, or medulla are observed
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• ~60% of adult female homozygotes show visibly moist skin in the external area surrounding the urogenital tract, along with hair loss in severe cases
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