Phenotypes for Ccdc188 MGI:8158267 MGI Mouse

abnormal sperm connecting piece morphology ( J:361702 )

• spermatids exhibit impaired head-to-neck anchoring

• while the sperm head-to-tail coupling apparatus assembles properly, it fails to attach to the nucleus during spermiogenesis, leading to sperm head and neck separation

abnormal sperm midpiece morphology ( J:361702 )

• sperm flagellum lacks the midpiece

absent sperm mitochondrial sheath ( J:361702 )

• almost all spermatozoa in the cauda epididymis lack a mitochondrial sheath

detached sperm flagellum ( J:361702 )

• 99.3%, 100%, and 100% of spermatozoa are acephalic in testis, caput epididymis, and cauda epididymis, respectively, indicating that separation of sperm head from the flagella occurs in the testis

• more sperm flagella than sperm heads are present in testes and epididymides and sperm heads are rarely found in the epididymis, implying that spermatid heads are removed by Sertoli cells and only sperm flagella transit into the epididymis

• spermatids undergo annulus migration normally, but step 16 spermatids exhibit an annulus with no principal piece, indicating that the flagella breaks between the midpiece and principal piece after mitochondrial assembly and only the principal piece gets released to the epididymis

short sperm flagellum ( J:361702 )

abnormal sperm head morphology ( J:361702 )

• most spermatozoa show abnormalities in the head region

absent sperm head ( J:361702 )

• most spermatozoa are acephalic

• however, a few sperm heads with normal morphology are seen but most of them do not have flagellum

• sperm heads are abnormally present within residual bodies in testes suggesting that the separated sperm heads are engulfed and absorbed by Sertoli cells

asthenozoospermia ( J:361702 )

• acephalic spermatozoa show a reduction in motility

male infertility ( J:361702 )

• even though copulatory plugs are seen, no pups are born indicating male infertility

• however, females are fertile