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Phenotypes Associated with This Genotype
Genotype
MGI:4358251
Allelic
Composition
Spo11tm1Mjn/Spo11tm1Mjn
Genetic
Background
involves: 129X1/SvJ * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Spo11tm1Mjn mutation (2 available); any Spo11 mutation (20 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
cellular
• normal numbers of oogonia are present at birth but oocyte numbers decline rapidly after birth
• at P4 and P8 only 10% - 20% of the normal number of c-kit positive oocytes are seen
• at 8 weeks of age oocyte depletion is more pronounced
• absence of epididymal sperm

reproductive system
• at 8 weeks of age ovarian dysgenesis is apparent
• at P13 the cortex of the ovary is nearly devoid of primordial follicles
• at P13, after the first cohort of oocytes is normally recruited to grow, the number of growing follicles is reduced 2 fold
• at 10 weeks of age only a few intermediate stage follicles and a single preovulatory follicle are seen
• slightly smaller compared to wild-type mice
• at 10 and 14 weeks of age testis weights are 20% - 50% of wild-type or heterozygous littermates
• at E15.5 most oocytes appear to be in the leptotene or early zygotene stage
• at E16.5 most oocytes still have an early zygotene morphology with a few reaching an abnormal zygotene like stage with long axial elements in synapsis but with partner exchanges
• at E17.5 most nuclei are either in an abnormal zygotene like stage or have appear to be fully synapsed but lack Scp1 expression
• normal numbers of oogonia are present at birth but oocyte numbers decline rapidly after birth
• at P4 and P8 only 10% - 20% of the normal number of c-kit positive oocytes are seen
• at 8 weeks of age oocyte depletion is more pronounced
• Dcm1/Rad51 foci are nearly absent suggesting mice are unable to initiate meiotic recombination
• oocytes display defects in synapsis
• increase in the incidence of apoptotic cells in the tubules
• absence of epididymal sperm
• few or no cells progress through meiosis
• Dcm1/Rad51 foci are nearly absent suggesting mice are unable to initiate meiotic recombination
• spermatocytes are seen with much longer axial elements and short synaptonemal complexes, with longer synaptonemal complexes but axial elements involved in synapsis with several partners, or without synaptonemal complexes
• spermatocyte nuclei with complete synapsis are not seen
• seminiferous tubules generally contain only spermatogonia and Sertoli cells or spermatogonia and Sertoli cells plus either early prophase spermatocytes or cells with highly condensed chromatin fragments
• no spermatocytes with pachytene or later morphology are seen

immune system
N
• despite expression patterns and the known role in double strand breaks in meiosis, no abnormalities in somatic hypermutation or class switch recombination are detected

endocrine/exocrine glands
• at 8 weeks of age ovarian dysgenesis is apparent
• at P13 the cortex of the ovary is nearly devoid of primordial follicles
• at P13, after the first cohort of oocytes is normally recruited to grow, the number of growing follicles is reduced 2 fold
• at 10 weeks of age only a few intermediate stage follicles and a single preovulatory follicle are seen
• slightly smaller compared to wild-type mice
• at 10 and 14 weeks of age testis weights are 20% - 50% of wild-type or heterozygous littermates


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
04/09/2024
MGI 6.23
The Jackson Laboratory