Phenotypes for Dicer1 Tg(NEUROG3-cre)1Herr MGI:6887647 MGI Mouse

teratozoospermia ( J:177677 )

• only very few cauda epididymal sperm appear normal: EM showed small abnormally shaped nuclei, bending of tails from the neck region, and excess of cytoplasm

abnormal sperm flagellum morphology ( J:177677 )

• cauda epididymal sperm show tail anomalies, including thin tails and disorganized accessory structures

thin sperm flagellum ( J:177677 )

abnormal sperm midpiece morphology ( J:177677 )

abnormal sperm mitochondrial sheath morphology ( J:177677 )

• some epididymal sperm tails exhibit a mislocalized mitochondrial sheath

absent sperm mitochondrial sheath ( J:177677 )

• some epididymal sperm tails show absence of the mitochondrial sheath

absent sperm fibrous sheath ( J:177677 )

• many epididymal sperm tails lack a detectable anti-AKAP4-positive fibrous sheath

kinked sperm flagellum ( J:177677 )

• some epididymal sperm show bending of tails from the neck region

abnormal sperm head morphology ( J:177677 )

• cauda epididymal sperm show defective head structures including small heads and abnormal head shapes

abnormal acrosome morphology ( J:177677 )

• fragmented acrosomes and abnormal acrosomal vacuoles are frequently observed and Golgi complexes appear remarkably prominent in round spermatids

abnormal sperm nucleus morphology ( J:177677 )

• several pin-head spermatozoa with tubulin-positive thin tails but no DAPI-positive nuclei are detected

• EM of epididymal sperm showed small abnormally shaped nuclei

• however, some germ cells are able to undergo condensation as shown by the presence of condensed nuclei among both testicular elongating spermatids and mature sperm

small sperm head ( J:177677 )

• epididymal sperm show small abnormal heads that are frequently bent over the tail

pinhead sperm ( J:177677 )

• pin-head sperm with tubulin-positive axonemal structures but no DAPI-positive heads are frequently detected

abnormal spermatid morphology ( J:177677 )

• condensed elongating spermatids show defects in head shaping, disorganized manchettes and abnormal bending of the head

• spermatid elongation is severely disrupted; only very few normal step 15-16 spermatids are detected

• nearly all late spermatids exhibit abnormal head shape and chromatin condensation and a disrupted organization of tail accessory structures including a disorganized midpiece

• step 9 spermatids show defective polarization of the head, with H1T2 (a testis-specific histone H1 variant) no longer polarized underneath the developing acrosome; instead, H1T2 shows a bipolar localization pattern at both the apical and basal side of the nucleus

abnormal manchette morphology ( J:177677 )

• step 9-12 elongating spermatids display a disorganized manchette

ectopic manchette ( J:177677 )

• anti-tubulin staining revealed that the manchette is distributed more randomly in the cytoplasm of elongating spermatids, often surrounding the whole nucleus

decreased male germ cell number ( J:177677 )

• at 8 weeks of age, the number of haploid germ cells is lower than that in control testis (53% versus 74.7%)

oligozoospermia ( J:177677 )

• number of mature spermatozoa is drastically reduced in the cauda epididymis

increased male germ cell apoptosis ( J:177677 )

• at 8 weeks of age, TUNEL staining revealed an increased number of apoptotic spermatocytes in the seminiferous tubules both at stages XII-I and at stages IV-V

small testis ( J:177677 )

• adult testis size is ~50% smaller than that in control males

abnormal spermiogenesis ( J:177677 )

• at 8 weeks of age, stage VII-VIII seminiferous tubules show a severe disruption in spermatid elongation, as determined by the amount, organization and nuclear morphology of elongating spermatids

• stages of the seminiferous epithelial cycle are often disorganized with haploid cells from different developmental stages being mixed in the same cross sections

• arrest in spermatid elongation appears to occur before initiation of nuclear condensation, as indicated by the high number of uncondensed elongating spermatids, presence of hyperacetylated H3-positive elongating spermatids in all the stages of seminiferous epithelial cycle, and low number of protamine-positive nuclei

• however, spermatogonia and early meiotic cells appear normal and overall organization of Sertoli and germ cells in the seminiferous epithelium is unaffected

abnormal epididymis morphology ( J:177677 )

• numerous exfoliated immature germ cells are frequently found in the epididymal lumen

male infertility ( J:177677 )

• adult males fail to sire pups after mating with wild-type females