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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Clcn2tm1Tjj
targeted mutation 1, Thomas J Jentsch
MGI:2183261
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Clcn2tm1Tjj/Clcn2tm1Tjj involves: 129S1/Sv * 129X1/SvJ * C57BL/6 MGI:3715612
cx2
Clcn2tm1Tjj/Clcn2tm1Tjj
Hepacamtm1.2Tjj/Hepacamtm1.2Tjj
involves: 129S1/Sv * 129X1/SvJ * C57BL/6NTac MGI:5646505


Genotype
MGI:3715612
hm1
Allelic
Composition
Clcn2tm1Tjj/Clcn2tm1Tjj
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Clcn2tm1Tjj mutation (0 available); any Clcn2 mutation (40 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
cellular
• germ cells at any stage are absent in males >6 months of age
• germ cells do not progress beyond meiosis I in mutant males
• mature sperms are totally absent in epididymis of mutant males
• clumps of dying spermatocytes are observed at 4 weeks in seminiferous tubules, and post-meiotic spermatids are absent

nervous system
N
• peripheral nervous system is relatively unaffected
• oligodendrocyte cell bodies and axons do not show morphological alterations in proximity to the vacuolations; also, no problems in myelin compaction is observed in peripheral nerves or in diameters of cerebellar myelin sheaths not directly affected by vacuolation
• barrier function is impaired at 8 months, but not at 5 weeks
• prominent vacuolation in fiber tracts of cerebellum
• prominent vacuolation in fiber tracts of internal capsule
• vacuole-like holes in large fiber tracts of brainstem at 22 months, but not at 14 days of age
• vacuolation most prominent in fiber tracts of cerebellum
• vacuole-like holes throughout white matter at 22 months, but not at 14 days of age (J:122365)
• vacuoles contain myelin sheets, and are surrounded by thin myelin sheaths (J:122365)
• severe myelin vacuolization (J:210308)
• white matter vacuolization (J:282228)
• myelin vacuolation visible in spinal cord at 22 months (J:122365)
• severe myelin vacuolization (J:210308)
• at P10, development is impaired relative to wild-type; displaced photoreceptor cells are seen beneath retinal pigment epithelium
• disorganization is apparent by P10; mice have shortened and whirled outer segments rather than parallel lines of outer segments with regular stacks of disks
• vacuole-like holes in spinal cord at 22 months, but not at 14 days of age
• absent Cl- currents in Bergmann glia
• cell capacitance is slightly increased in Bergmann glia
• at 8 months, mutants but not wild-type mice show microglial activation in the brain; such activation is not apparent at 5 weeks
• membrane capacitance is increased
• reduction in conduction velocity is observed; latency between peaks I and III in the auditory pathway is increased at 5 and 12 weeks of age

behavior/neurological
N
• mice do not show overt seizures, or increased sensitivity to fluorethyl which induces seizures (J:68137)
• motor learning and coordination are similar to wild-type (J:122365)
• mice have similar seizure susceptibilities as wild-type mice, on exposure to fluorethyl or pentylenetetrazol (J:122365)

reproductive system
• germ cells at any stage are absent in males >6 months of age
• germ cells do not progress beyond meiosis I in mutant males
• mature sperms are totally absent in epididymis of mutant males
• clumps of dying spermatocytes are observed at 4 weeks in seminiferous tubules, and post-meiotic spermatids are absent
• at 3 weeks of age, tubules lack lumina, and contain predominantly Sertoli cells, few spermatogonia, and abnormal clusters of primary spermatocytes
• by 4 weeks, tubules are smaller than in wild-type, lack lumina, and are filled mainly by Sertoli cells with long cytoplasmic extensions
• cells have abnormal cytoplasmic extensions
• degeneration with markedly reduced diameters and obliterated lumina; lumina are filled with membranous extensions of abnormal Sertoli cells
• at 2 weeks of age, germinal epithelium is disorganized
• markers of germ cell development such as proacosin binding protein and Ccna1 which can be detected in wild-type at 3 weeks are completely absent in males at any age
• Sertoli cells lack chloride currents
• relative numbers of interstitial Leydig cells is increased in males >6 months of age
• noticeable by 3 weeks of age, testes of males are markedly reduced in size relative to wild-type
• testicular degeneration
• homozygous males produce no litters despite normal copulatory behavior and vaginal plug formation in females after mating

vision/eye
• at P10, development is impaired relative to wild-type; displaced photoreceptor cells are seen beneath retinal pigment epithelium
• disorganization is apparent by P10; mice have shortened and whirled outer segments rather than parallel lines of outer segments with regular stacks of disks
• at P14, the outer nuclear layer contains large numbers of pyknotic nuclei and cell number is decreased by ~50%
• thickness of ONL decreases over next few weeks, such that at P31 only one or two rows of photoreceptor nuclei are present; at P65, only a few nuclei remain
• mice kept in darkness from P0 to P35 show similar retinal degeneration to mice exposed to light
• transepithelial transport across retinal pigment epithelium at P36 is significantly reduced relative to wild-type; transepithelial voltages are reduced from -6 mV in controls to <0.5 mV, and short circuit current across RPE is reduced

cardiovascular system
• barrier function is impaired at 8 months, but not at 5 weeks

endocrine/exocrine glands
N
• androgen levels and testosterone secretion by Leydig cells is similar to wild-type males
• at 3 weeks of age, tubules lack lumina, and contain predominantly Sertoli cells, few spermatogonia, and abnormal clusters of primary spermatocytes
• by 4 weeks, tubules are smaller than in wild-type, lack lumina, and are filled mainly by Sertoli cells with long cytoplasmic extensions
• cells have abnormal cytoplasmic extensions
• degeneration with markedly reduced diameters and obliterated lumina; lumina are filled with membranous extensions of abnormal Sertoli cells
• at 2 weeks of age, germinal epithelium is disorganized
• markers of germ cell development such as proacosin binding protein and Ccna1 which can be detected in wild-type at 3 weeks are completely absent in males at any age
• Sertoli cells lack chloride currents
• relative numbers of interstitial Leydig cells is increased in males >6 months of age
• noticeable by 3 weeks of age, testes of males are markedly reduced in size relative to wild-type
• testicular degeneration

homeostasis/metabolism
N
• mutants show normal serum concentrations of electrolytes, creatine, and liver-derived enzymes, as well as gastic acidification
• mice exhibit elevated plasma renin concentration
• however, mice exhibit unaltered plasma aldosterone levels

immune system
• at 8 months, mutants but not wild-type mice show microglial activation in the brain; such activation is not apparent at 5 weeks

hematopoietic system
• at 8 months, mutants but not wild-type mice show microglial activation in the brain; such activation is not apparent at 5 weeks




Genotype
MGI:5646505
cx2
Allelic
Composition
Clcn2tm1Tjj/Clcn2tm1Tjj
Hepacamtm1.2Tjj/Hepacamtm1.2Tjj
Genetic
Background
involves: 129S1/Sv * 129X1/SvJ * C57BL/6NTac
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Clcn2tm1Tjj mutation (0 available); any Clcn2 mutation (40 available)
Hepacamtm1.2Tjj mutation (0 available); any Hepacam mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• myelin vacuolization is increased compared to either single homozygote





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last database update
12/10/2024
MGI 6.24
The Jackson Laboratory