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Phenotypes Associated with This Genotype
Genotype
MGI:6874588
Allelic
Composition
Spag4tm1(KOMP)Mbp/Spag4tm1(KOMP)Mbp
Genetic
Background
involves: C57BL/6J * C57BL/6N
Cell Lines DEPD00501_2_E02
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Spag4tm1(KOMP)Mbp mutation (1 available); any Spag4 mutation (17 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system
N
• female mice are fertile
• outer dense fiber aberrations are observed in the principal piece
• although formation of the head-to-tail coupling apparatus (HTCA) is normal, condensed spermatids and epididymal spermatozoa exhibit a diminished attachment site with obvious detachment of the lateral parts of the basal plate from the nuclear membrane, suggesting that tightening of the sperm head-to-tail anchorage is affected
• principal piece region shows numerical and structural aberrations with disorganized or missing microtubule doublets and their accompanying outer dense fibers
• in contrast, midpiece formation is normal with a well-organized mitochondrial sheath, axoneme and outer dense fibers
• epididymal spermatozoa are rarely found but, if present, are misshapen
• as spermiogenesis proceeds, spermatids exhibit a severely malformed acrosome
• epididymal sperm exhibit a characteristic malformed, globular head
• spermatid nuclei do not properly elongate and remain spherical with a malformed acrosome
• although nuclear condensation is observed, reshaping and final nuclear compaction do not occur
• round spermatids appear normal with a properly developed acrosome; however, as spermiogenesis proceeds spermatids lack a distinct manchette and show severe malformation of the nucleus and the acrosome
• elongated spermatids are rarely found in the testis and epididymis
• manchettes are malformed and frequently detached indicating impaired linkage of the manchette to the spermatid nucleus
• however, manchette microtubules are acetylated indicating the presence of stable microtubules and a sperm tail develops at the posterior pole of the nucleus similar to wild-type cells
• spermatid manchette is frequently detached from the nuclear envelope
• although spermatogenesis appears to progress to the round spermatid stage, elongated spermatids are rarely found in the seminiferous tubules and epididymis
• males are completely infertile

cellular
• outer dense fiber aberrations are observed in the principal piece
• although formation of the head-to-tail coupling apparatus (HTCA) is normal, condensed spermatids and epididymal spermatozoa exhibit a diminished attachment site with obvious detachment of the lateral parts of the basal plate from the nuclear membrane, suggesting that tightening of the sperm head-to-tail anchorage is affected
• principal piece region shows numerical and structural aberrations with disorganized or missing microtubule doublets and their accompanying outer dense fibers
• in contrast, midpiece formation is normal with a well-organized mitochondrial sheath, axoneme and outer dense fibers
• epididymal spermatozoa are rarely found but, if present, are misshapen
• as spermiogenesis proceeds, spermatids exhibit a severely malformed acrosome
• epididymal sperm exhibit a characteristic malformed, globular head
• spermatid nuclei do not properly elongate and remain spherical with a malformed acrosome
• although nuclear condensation is observed, reshaping and final nuclear compaction do not occur
• round spermatids appear normal with a properly developed acrosome; however, as spermiogenesis proceeds spermatids lack a distinct manchette and show severe malformation of the nucleus and the acrosome
• elongated spermatids are rarely found in the testis and epididymis
• manchettes are malformed and frequently detached indicating impaired linkage of the manchette to the spermatid nucleus
• however, manchette microtubules are acetylated indicating the presence of stable microtubules and a sperm tail develops at the posterior pole of the nucleus similar to wild-type cells
• spermatid manchette is frequently detached from the nuclear envelope


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
05/21/2024
MGI 6.23
The Jackson Laboratory