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At least 19 recordsLinked to original sources
PubMed1979

Characterization of Sertoli cell-germ cell junctional specializations in dissociated testicular cells.

To further characterize Sertoli cell-germ cell junctional specializations seminiferous tubules from sexually mature Sprague-Dawley rats were dissociated by enzymatic and mechanical methods. Ultrastructural analysis of cell suspensions prepared by incubation in collagenase alone or by mechanical methods revealed that spermatids remained attached to Sertoli cells or Sertoli cell fragments. Such cellular associations were found only between Sertoli cell fragments and spematids in which the developing acrosome had made contact with the plasma membrane (step 8 and subsequent steps of spermiogenesis). Furthermore, the fragments were confined to that region of the plasma membrane over the acrosome. The Sertoli cell half of this adhesive site displayed the typical elements of Sertoli cell junctions, filamentous bundles and associated cisterna of endoplasmic reticulum, in apposition to the spermatids. The spermatids demonstrated no surface specializations at the attachment sites. In contrast, in cell suspensions prepared with trypsin, spermatids were free of attachments to Sertoli cells or their fragments. These results demonstrate that: (1) the junctions act to bind cells together, (2) adhesive type contact is established between Sertoli cells and spermatids at step 8 and subsequent steps of spermiogenesis, (3) contact is restricted to the spermatid plasma membrane over the acrosome, and (4) spermatids can be freed from the junctional specializations by treatment with trypsin.

Animals↗
PubMed1979

Interrelationships between Sertoli cells and germ cells in the Syrian hamster.

The interrelationships of the Sertoli cells and germ cells in the Syrian hamster were examined using the electron microscope. Demosome-like junctions were observed attaching Sertoli cells to spermatogonia and spermatocytes. In the region of the junctions dense plaques lay on the cytoplasmic surfaces of the plasmalemma of the opposing cells. Sertoli cell cytoplasmic filaments converged in the area of the junctions and inserted into the subsurface densities. Filaments were not observed associated with the subsurface densities of the germ cells. In the region of the junctions a 15...20 nm gap, filled with an attenuate amorphous substance, separated the plasmalemmata. Another attachment device termed "junctional specialization" occurred between Sertoli cells, and preleptotene spermatocytes and all successive developmental steps in the germ cell line in the hamster. The junctional specializations consisted of a mantel of Sertoli cell cytoplasmic filament lying subjacent to the Sertoli cell plasmalemma and an opposed cisterna of the endoplasmic reticulum. In stages VII-VIII preleptotene supermatocytes were observed in transit from the basal compartment to the adluminal compartment. While Sertoli-Sertoli junctions adluminal to the spermatocytes remained intact, typical Sertoli-Sertoli junctions formed between opposed Sertoli cell processes basal to the spermatocytes. It is proposed that, during the passage of spermatocytes in to the adluminal compartment, junctional specializations associated with preleptotene spermatocytes in the basal compartment migrate basal to the spermatocytes and contribute to formation of Sertoli-Sertoli junctions. Treatment of seminiferous tubules with hypertonic media was used to demonstrate that the junctional specializations function in cell-to-cell adhesion. Data indicated that these junctions function to retain the developing spermatids within the seminiferous epithelijm until the time of spermiation. At spermination the junctional specializations disappear and the spermatids drift off into the tubule lumen.

Animals↗
PubMed2026

Overlapping genetic etiology of pediatric and adult germ cell tumors.

BACKGROUND: Germ cell tumors are heterogeneous neoplasms arising from primordial germ cells. Although genome-wide association studies have identified numerous susceptibility loci for adult testicular germ cell tumors, the heritable basis of pediatric testicular germ cell tumors and germ cell tumors that arise outside the testes remain poorly understood. METHODS: We conducted a multi-ancestry genome-wide association study of pediatric germ cell tumors, including 1927 cases from the Germ Cell Tumor Epidemiology Study and 10 601 controls. Cases were diagnosed with testicular (n = 678), ovarian (n = 441), intracranial (n = 435), and extragonadal (n = 373) germ cell tumor between the ages of 0 and 19 years. RESULTS: We identified 4 loci reaching genome-wide significance, including variants near BAK1 (chr 6: rs3831846), SPRY4 (chr 5: rs12515244), DMRT1 (chromosome [chr] 9: rs10815910), and DEPTOR (chr 8: rs13277786). Additional genome-wide statistically significant associations were identified in subgroup analyses, including 6 loci for intracranial germ cell tumors (rs2758612 [PMF1/BGLAP], rs9854760 [PLCL2], rs6851498 [KIT], rs11816992 on chromosome 10, rs3830273 [TFAM], and rs13054014 [LZTR1]), 1 locus for testicular germ cell tumor (rs1907702 [KITLG]), and 1 locus for males (rs4610628 [MAD1L1]). After Bonferroni correction, 18 of 78 previously reported testicular germ cell tumor loci were significantly associated with germ cell tumor overall or in at least 1 subgroup with a particularly strong correlation between testicular germ cell tumor and intracranial germ cell tumor effect estimates (rho = 0.63, P = 5.5 × 10-10). Expression quantitative trait locus (QTL) analyses identified candidate genes in the regions identified on chromosome 6 (BAK1, LINC003366, and ITPR3) and chromosome 8 (DEPTOR and RP11-760H22.2). CONCLUSIONS: Our data support a role for germline genetic variation in the development of germ cell tumors in locations outside the testes and highlight shared genetic architecture across age group and tumor location.

Humans↗
PubMed1975

Chemical induction of presumed dominant-lethal mutations in postcopulation germ cells of mice. I. Relative sensitivity between pre- and postcopulation germ cells to isopropyl methanesulfonate.

Females from (C3H X 101)F1 and a mixed stock were injected intraperitoneally with either 25 or 50 mg/kg isopropyl methanesulfonate (IMS) or Hanks' solution 4-5 h after the midpoint of the dark period during which mating occurred. It was determined that at the time of treatment the great majority of oocytes were undergoing second meiotic division. For comparison, the same doses of IMS were given to females treated within 3-5 days prior to mating (predominantly dictyate oocytes) or to males treated within 4-5 days prior to mating (sperm in vas and epididymis). The frequencies of presumed dominant lethals induced by 50 mg/kg IMS in sperm treated in vas and epididymis, dictyate oocytes, and germ cells in mated females are 22%, 19%, and 79%, respectively, for (C3H X 101)F1 and 26%, 30%, and 76% for the other stock. Clearly, in both stocks, effects in mated females, when both female and male germ cells were treated, are relatively much higher than the added effects on dyctyate oocytes and spermatozoa. This is also true for the 25 mg/kg dose.

Animals↗
PubMed1978

Mediastinal extragonadal germ cell tumors.

Mediastinal germ cell tumors are a rare primary malignancy. An overview of the presenting clinical symptoms, radiographic appearance, patterns of extention and metastasis, and autopsy findings are presented. The difficulty in totally excluding an occult gonadal primary lesion in noted. The theories of the genesis of these tumors are briefly reviewed.

Adolescent↗
PubMed1977

Pathology of germ cell tumors of the testis.

Testicular germ cell tumors form a complex group of interrelated entities. Problems of nomenclature remain, but there does appear to be a close agreement between the major classifications in use. The identification of clinically useful markers for certain germ cell testicular tumors has provided a major impetus in this field. Information gained from the study of these markers has promoted an understanding of the histogenesis of germ cell tumors, has improved standard nomenclature, and has stimulated progress in patient care. Radioimmunoassay techniques are now frequently used to measure beta-human chorionic gonadotrophin and alpha-fetoprotein levels in evaluating the clinical course of patients with nonseminomatous germ cell tumors of the testis. It is hoped that the use of these markers will permit earlier detection of tumor recurrence, prompt treatment, and an improved survival rate. The knowledge of the production of alpha-fetoprotein by the human yolk sac has further refined tumor classification. It is against this general background that we have outlined the standard pathology of germ cell tumors of the testis.

Choriocarcinoma↗
PubMed1979

Morphological characteristics of male germ cells of rats in contact with Sertoli cells in vitro.

Fragments of seminiferous epithelium were prepared from 3-week-old rats. Although the Sertoli cells formed a monolayer, germ cells (spermatogonia and early spermatocytes) remained in association with them and were of normal ultrastructural appearance. Germ cells became completely separated from Sertoli cells after 3 weeks of culture in a chemically defined medium. The contact areas between Sertoli and germ cells were characterized by desmosome-like junctions while those between germ cells appeared to be pentalaminar.

Animals↗
PubMed1978

Characterization of a xenogeneic antiserum raised against the fetal germ cells of the mouse: cross-reactivity with embryonal carcinoma cells.

A xenogeneic antiserum (PG-1) raised against the germ cells of the 13.5d p.c. mouse conceptus reacts with the fetal germ cells of both sexes and adult male germ cells, but not with any nongerminal tissue that has been tested. PG-1 can also react with the EC cells of four different teratocarcinoma cell lines. There are, however, marked differences in the absorptive capacity of the different EC cell lines. The antigen(s) recognized by the antiserum are confined to only a proportion of cells in some EC lines. This antiserum has a number of potential applications in studies of the origin and development of the mouse germ cell lineage.

Animals↗
PubMed1979

A cell surface antigen, TER, expressed by embryos and germ cells.

An antiserum prepared in rabbits against the C3HeB/FeJ mouse ovarian teratocarcinoma E6496 was absorbed in vivo in C3HeB/FeJ mice. This absored antiserum identified an antigen, denoted TER, that is present on sperm, ova, embryonic germ cells, and cells of the early mouse embryo. TER was absent from all adult somatic cells tested, but found on several murine tumors.

Absorption↗
PubMed1979

Germ cell neoplasms arising in gonadoblastomas.

Gonadoblastomas have a propensity to give rise to germ cell neoplasms. This study analyzes the clinicopathologic findings in six phenotypic females with features of 46,XY pure gonadal dysgenesis who developed germinomas and other germ cell tumors in gonadoblastomas. All stages in the evolution of germinoma from the germ cells of gonadoblastoma were observed, including in situ, incipient, microinvasive, and metastatic varieties. Admixtures with teratoma and endodermal sinus tumor occurred in two patients. Germ cell tumors which originate in gonadoblastomas appear to have the same clinical behavior and response to therapy as those that arise de novo in the ovary, testis or extragonadal sites. Although it is debatable whether gonadoblastomas are true neoplasms or blastomatoid dysgenetic malformations, their potential for giving rise to fully malignant germ cell neoplasms must be recognized.

Adolescent↗
PubMed1979

Germ cells and ova in dysgenetic gonads of a 46-XY female dizygotic twin.

The frequency of germ cell neoplasms in girls with 46-XY gonadal dysgenesis suggests that germ cells may persist in the dysgenetic gonads for many years. A phenotypic female infant with a karyotype of 46-XY in blood, skin, and gonads had a few ova in primordial follicles and numerous germ cells in her dysgenetic gonads at the age of 3 months. At 3 years and 10 months of age her gonads contained no primordial follicle and the only remaining germ cells were in a gonadoblastoma. We propose that germ cells are lost from dysgenetic gonads much more rapidly than from normal gonads, but that the rate of loss in patients with a karyotype of 46-XY may be less than the rate of loss in patients with a karyotype of 45-XO.

Child, Preschool↗
PubMed1979

Germ cell malignancies of the ovary.

Historically, ovarian germ cell malignancies carry a very poor prognosis. The use of surgery alone or in combination with radiation therapy does not appreciably increase survival. The combination of surgery, chemotherapy, and, in some instances, radiation therapy has accounted for an 89% two-year survival in 26 patients with germ cell malignancies of the ovary exclusive of "pure" dysgerminoma. Short-term chemotherapy appears as effective as the long-term therapy advocated by other investigators.

Animals↗
PubMed2026

DAZL-targeted inducible kill switches enable efficient ablation of chicken primordial germ cells.

Competition from endogenous primordial germ cells (PGCs) in recipient embryos limits the generation of fully donor-derived offspring in avian surrogate-host systems. An inducible and germline-restricted ablation strategy is therefore needed to create sterile recipients without compromising somatic development. Using CRISPR/Cas9-mediated homology-directed repair, we inserted three inducible suicide-gene cassettes (iCaspase9, RapaCasp9, and CD) into the endogenous DAZL locus of chicken PGCs. All knock-in lines showed stable reporter expression and retained typical PGC morphology. Comparative functional analyses identified iCaspase9 activated by AP20187 as the most sensitive and specific ablation system, achieving near-complete killing at nanomolar concentrations without detectable toxicity in control cells. RapaCasp9 induced with rapamycin also ablated engineered PGCs efficiently, but rapamycin caused marked non-specific growth inhibition in control cells. Replacing rapamycin with the synthetic A/C heterodimerizer AP21967 largely eliminated this off-target toxicity while preserving rapid and robust killing. By contrast, yeast-derived CD variants did not substantially improve 5-fluorocytosine sensitivity in chicken PGCs. DAZL-restricted iCaspase9/AP20187 and the optimized RapaCasp9/AP21967 system provide efficient inducible kill switches for chicken PGCs in vitro. These platforms establish a practical genetic toolkit for generating sterile surrogate hosts to support avian genome editing, germline replacement, and Sire Dam Surrogate breeding.

CRISPR/Cas9↗
PubMed1979

Morphological, histochemical and biochemical studies on germ cell mitochondria of normal rats.

Morphological changes in rat germ cell mitochondria are described. In diplotene and secondary spermatocytes and in the spermatids of the Golgi, cap and acrosomal phases, the mitochondria take on a rounded appearance with the inner space containing the matrix flattened against the outer membrane and the intracristal spaces considerably swollen ("condensed" mitochondria). Functional studies on "condensed" mitochondria isolated from the germ cells of normal rats have been performed. The following parameters have been evaluated: ADP/O ratio, respiratory control ratio (RCR) and ADP affinity. The ADP/O values found in the presence of various substrates are in agreement with the theoretical figures. The RCR is remarkably high. Moreover, the ADP affinity of these mitochondria is very high, as demonstrated by the low values of the "apparent Km". These biochemical findings, which demonstrate a high oxidative capacity coupled with a marked phosphorylation, suggest that the "condensed" appearance of germ cell mitochondria is the expression of an active functional state.

Adenosine Diphosphate↗
PubMed1977

Cytogenetic observations on XX/XY chimaeras and a reassessement of the evidence for germ cell chimaerism in heterosexual twin cattle and marmosets.

Testicular preparations were obtained from 7 bulls, twins of freemartins, and 1 male marmoset, all proved XX/XY chimaeras. X and Y sex chromosomes were confidently identified in nearly all the 87 spermatogonia at mitotic metaphase and 1052 primary spermatocytes at diakinesis-metaphase examined: no cell was identified as containing two X chromosomes. The germ cell chimaerism previously reported in these species is therefore not confirmed. Cultures grown from presumptive somatic these species is therefore not confirmed. Cultures grown from presumptive somatic cells in the testes of two of the bulls yielded 248 identifiable mitotic spreads, all XY-type; cultures from the gonads of their freemartin twins yielded 442 mitotic spreads, all XX-type. Direct preparations from one freemartin gonad, however, yielded 3 XY mitotic spreads out of 18 examined. The conflicting evidence concerning germ cell chimaerism in cattle and marmosets is discussed, particularly in relation to reports of XX/XY bulls that have sired a great excess of daughters. The possibility that XX germ cells contributed to the functional spermatozoa of these bulls is not favoured by present information, but is not excluded.

Animals↗