Disease relevance of Spermatids

• Temporal expression of transition proteins and protamines during spermatid differentiation is under translational control, and premature translation of protamine 1 leads to precocious nuclear condensation and sterility [1].
• Postmeiotic expression is maximal in the round spermatids of stages VII and VIII, suggesting that CFTR plays a critical role in spermatogenesis and that deficiency of this function contributes to CF male infertility [2].
• HSV-1 TK was expressed in germ line cells, mainly in the haploid spermatids [3].
• Disrupted spermatogenesis, defined by at least a 75% reduction of round spermatids, was observed in 42 +/- 5.8% of seminiferous tubules 14 days after AdCREBm1 infection, whereas using this criteria, testes injected with a control adenovirus did not display disrupted spermatogenesis [4].
• Orchiopexy maintained for 35 days following 60 days of cryptorchidism allowed germ cells to regenerate to spermatids at steps 1-14 of sperminogenesis (1st layer spermatids), but failed to change the intracellular localization of the Golgi apparatus in Sertoli cells [5].

High impact information on Spermatids

• Maturation of spermatids is unsynchronized and impaired in seminiferous tubules of Cnot7(-/-) mice [6].
• The sequential deposition of sperm basic nuclear proteins on chromatin is disrupted, with a specific loss of protamine-2 and prolonged retention of transition protein-2 (Tnp2) in step-15 spermatids [7].
• Elongating spermatids are not transcriptionally active, raising the possibility that Camk4 has a novel function in male germ cells [7].
• Deletion of the AZF region is associated with highly variable testicular defects, ranging from complete absence of germ cells to spermatogenic arrest with occasional production of condensed spermatids [8].
• In males CFTR mRNA is found in the round spermatids (spermatogenic stages V-X) and in the principal cells that line the initial segment of the epididymis [9].

Chemical compound and disease context of Spermatids

• Use of polyethylene glycol rather than inactivated Sendai virus as the cell fusion agent was found to be essential to the production of large numbers of heterokaryons containing spermatid nuclei [10].
• Both results as well as morphological examination of testis after busulphan injection and artificial cryptorchidism revealed that spermatocytes and spermatids represent the testicular cell fraction containing the elevated amount of beta-pol mRNA [11].

Biological context of Spermatids

• In contrast, mice of the widely used CD-1 line, which has been selected for large litter size, showed little or no inhibition of spermatid maturation even in response to 16 times as much E2 [12].
• These results suggest that spe-26 encodes a cytoskeletal protein, perhaps actin binding, which is necessary to segregate the cellular components that form haploid spermatids [13].
• In adults, the data suggest that Zfy-1 and Zfy-2 transcription is linked to spermatogenesis, that transcription increases with the initiation of meiosis, and that high levels of these mRNAs are found in postmeiotic round spermatid cells [14].
• Indirect immunofluorescent studies show RHL-2/3-like immunoreactivity on the surface of Sertoli cell, meiotic prophase spermatocytes, spermatids, and epididymal sperm [15].
• Phosphorylation in spermatids, and probably at fertilization, occurs at repeated -Ser-Pro-X-Basic-motifs in the distinctive N-terminal basic domains of both histones and at the end of the much longer C-terminal domain of H1 [16].

Anatomical context of Spermatids

• The sodium- and potassium-transporting ionophore monensin induces the maturation of Caenorhabditis elegans spermatids to spermatozoa in vitro [17].
• Administration of EGF to sialoadenectomized mice restored both the sperm content of the epididymis and the number of spermatids in the testis to normal [18].
• In wild-type spermatids, Hrb is associated with the cytosolic surface of proacrosomic transport vesicles that fuse to create a single large acrosomic vesicle at step 3 of spermiogenesis [19].
• Synthesis of hGH in early round spermatids resulted in localization in the acrosome, whereas synthesis in late elongating spermatids resulted in intracellular, but not acrosomal, localization [20].
• We hypothesize that the abnormal microtubules in these two cell types are responsible for deformation of spermatid nuclei and germ cell loss, respectively, and indicate an essential role for E-MAP-115 in microtubule functions required for spermatogenesis [21].

Associations of Spermatids with chemical compounds

• Vesicle fusion, pseudopod extension and amoeboid motility are induced in nematode spermatids by the ionophore monensin [17].
• Spermatid bundles from such males do not exhibit the normal transition from lysine-rich to arginine-rich histones [22].
• The testicular cell suspension from which spermatids are separated, like whole testis and spermatids themselves, show higher incorporation of amino acids into TCA-precipitable material at 34 degrees C than at 38 degrees C and in the presence of glucose [23].
• Immature spermatids prepared by this method use glucose with an increase in oxygen consumption, lactate production, and protein synthesis over control levels (no glucose) [23].
• By contrast, lysine was initially incorporated only into late step-12 and step-13 spermatid nuclei, and was retained only to early step 14 of spermiogenesis [24].

Gene context of Spermatids

• We demonstrate here that Sbf1, a pseudophosphatase of the myotubularin family, is expressed at high levels in seminiferous tubules of the testis, specifically in Sertoli's cells, spermatogonia, and pachytene spermatocytes, but not in postmeiotic round spermatids [25].
• The axonemes of elongating spermatids react with antibodies against the Drosophila laminin B1, B2 and laminin A chains [26].
• Antigenic sites against laminin B2 were found in the lampbrush loops in primary spermatocyte nuclei, in nuclei of spermatids, and in heads of spermatozoa [26].
• Dpl protein was expressed at late stages of spermiogenesis, and spermatids of Dpl mutants were reduced in numbers, immobile, malformed and unable to fertilize oocytes in vitro [27].
• Premature accumulation of Prm1 within syncytial spermatids in mice hemizygous for the transgene caused dominant male sterility, which in some cases was accompanied by a complete arrest in spermatid differentiation [28].

Analytical, diagnostic and therapeutic context of Spermatids

• In situ hybridization with a cDNA probe for the Prm-1 gene transcript performed on both whole testis sections and spermatogenic cell suspensions showed that there was no statistical difference in distribution of grains over step-5 to step-10 spermatids from Robertsonian-translocation heterozygous mice and from control mice of normal karyotype [29].
• Immunofluorescence studies revealed CCK-like peptides primarily in spermatocytes and spermatids of mouse, rat, and monkey [30].
• Immuno electron microscopy of monkey testis demonstrated CCK immunoreactivity in the acrosomal granule of spermatids [30].
• The immunohistochemistry of testis localized the AQP7 expression at late spermatids and at maturing sperms [31].
• Northern blotting and in situ hybridization confirmed the testis-specific expression of murine Sptrx-2 mRNA, mostly in round spermatids [32].

References