Histological and quantitative changes in the annual testicular cycle of Triturus marmoratus marmoratus

1990 ◽  
Vol 68 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Francisco Jose Saez ◽  
Benito Fraile ◽  
Ricardo Paniagua
Keyword(s):  
Endoplasmic Reticulum ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Light And Electron Microscopy ◽  
Second Phase ◽  
Glandular Tissue ◽  
Quantitative Studies ◽  
Quantitative Changes ◽  
Triturus Marmoratus

Eight male marbled newts (Triturus marmoratus marmoratus) were collected on the 15th of each month in 1987 and their testes were studied by light and electron microscopy. Quantitative studies also were performed to establish the annual testicular cycle and the total volume per testis occupied by each germ cell type throughout the year. Characteristic ultrastructural features of germ cells are the occurrence of a well-developed Golgi complex in primary spermatogonia; multiple small dictyosomes and nuclear blebs in primary spermatocytes; peripherally situated mitochondria; long strands of endoplasmic reticulum and subsurface cisternae in round spermatids; and abundant rough endoplasmic reticulum in follicular cells. Secondary spermatocytes have a short or absent interphase and are observed in the prophase. The annual testicular cycle comprises three periods: (i) germ cell proliferation (May–June), characterized by the formation of primary spermatocytes that undergo meiosis, giving rise to round spermatids; (ii) spermiogenesis (July–September), during which round spermatids develop into spermatozoa and the interstitial boundary cells are transformed into glandular tissue cells; and (iii) testicular quiescence (October–April) in which the testis contains only spermatozoa, glandular tissue, and a few primordial germ cells and spermatogonia. In the second phase of testicular quiescence (February–April) spermatozoa are released from the testis and proliferation of secondary spermatogonia occurs.

Electron microscope study of the effects of radiation on insect fertility

1990 ◽  
Vol 48 (3) ◽  
pp. 72-73
Author(s):  
Judy Ju-Hu Chiang ◽  
Robert Kuo-Cheng Chen
Keyword(s):  
Electron Microscopy ◽  
Germ Cell ◽  
Germ Cells ◽  
Electron Microscope Study ◽  
Radiation Treatment ◽  
Light And Electron Microscopy ◽  
Stem Borer ◽  
Metabolic Energy ◽  
Rice Stem Borer ◽  
Effects Of Radiation

Germ cells from the rice stem borer Chilo suppresalis, were examined by light and electron microscopy. Damages to organelles within the germ cells were observed. The mitochondria, which provide the cell with metabolic energy, were seen to disintegrate within the germ cell. Lysosomes within the germ cell were also seen to disintegrate. The subsequent release of hydrolytic enzymesmay be responsible for the destruction of organelles within the germ cell. Insect spermatozoa were seen to lose the ability to move because of radiation treatment. Damage to the centrioles, one of which is in contact with the tail, may be involved in causing sperm immobility.

scholarly journals Ligand–Receptor Interactions Elucidate Sex-Specific Pathways in the Trajectory From Primordial Germ Cells to Gonia During Human Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Arend W. Overeem ◽  
Yolanda W. Chang ◽  
Jeroen Spruit ◽  
Celine M. Roelse ◽  
Susana M. Chuva De Sousa Lopes
Keyword(s):  
Germ Cell ◽  
Signaling Pathways ◽  
Germ Cells ◽  
Tyrosine Kinases ◽  
Intracellular Localization ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Systematic Analysis ◽  
Receptor Interactions

The human germ cell lineage originates from primordial germ cells (PGCs), which are specified at approximately the third week of development. Our understanding of the signaling pathways that control this event has significantly increased in recent years and that has enabled the generation of PGC-like cells (PGCLCs) from pluripotent stem cells in vitro. However, the signaling pathways that drive the transition of PGCs into gonia (prospermatogonia in males or premeiotic oogonia in females) remain unclear, and we are presently unable to mimic this step in vitro in the absence of gonadal tissue. Therefore, we have analyzed single-cell transcriptomics data of human fetal gonads to map the molecular interactions during the sex-specific transition from PGCs to gonia. The CellPhoneDB algorithm was used to identify significant ligand–receptor interactions between germ cells and their sex-specific neighboring gonadal somatic cells, focusing on four major signaling pathways WNT, NOTCH, TGFβ/BMP, and receptor tyrosine kinases (RTK). Subsequently, the expression and intracellular localization of key effectors for these pathways were validated in human fetal gonads by immunostaining. This approach provided a systematic analysis of the signaling environment in developing human gonads and revealed sex-specific signaling pathways during human premeiotic germ cell development. This work serves as a foundation to understand the transition from PGCs to premeiotic oogonia or prospermatogonia and identifies sex-specific signaling pathways that are of interest in the step-by-step reconstitution of human gametogenesis in vitro.

scholarly journals Phase Transitioned Nuclear Oskar Promotes Cell Division of Drosophila Primordial Germ Cells

2018 ◽  
Author(s):  
Kathryn E. Kistler ◽  
Tatjana Trcek ◽  
Thomas R. Hurd ◽  
Ruoyu Chen ◽  
Feng-Xia Liang ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Cell Function ◽  
Primordial Germ Cells ◽  
Nuclear Localization Sequence ◽  
Cell Systems ◽  
Germ Granules ◽  
Localization Sequence ◽  
Transcriptional Gene Regulation

ABSTRACTGerm granules are non-membranous ribonucleoprotein granules deemed the hubs for post-transcriptional gene regulation and functionally linked to germ cell fate across species. Little is known about the physical properties of germ granules and how these relate to germ cell function. Here we study two types of germ granules in the Drosophila embryo: cytoplasmic germ granules that instruct primordial germ cells (PGCs) formation and nuclear germ granules within early PGCs with unknown function. We show that cytoplasmic and nuclear germ granules are phase transitioned condensates nucleated by Oskar protein that display liquid as well as hydrogel-like properties. Focusing on nuclear granules, we find that Oskar drives their formation in heterologous cell systems. Multiple, independent Oskar protein domains synergize to promote granule phase separation. Deletion of Oskar’s nuclear localization sequence specifically ablates nuclear granules in cell systems. In the embryo, nuclear germ granules promote germ cell divisions thereby increasing PGC number for the next generation.

scholarly journals Disruption of Tcfap2c in Primordial Germ Cells using Prdm1-Cre Prevents Germ Cell Development

2008 ◽  
Vol 78 (Suppl_1) ◽  
pp. 64-64
Author(s):  
Jillian Guttormsen ◽  
Gerrit J. Bouma ◽  
Frances Bhushan ◽  
Trevor Williams ◽  
Quinton A. Winger
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Cell Development ◽  
Germ Cell Development

Increased proportion of donor primordial germ cells in chimeric gonads by sterilisation of recipient embryos using busulfan sustained-release emulsion in chickens

2008 ◽  
Vol 20 (8) ◽  
pp. 900 ◽  
Author(s):  
Yoshiaki Nakamura ◽  
Yasuhiro Yamamoto ◽  
Fumitake Usui ◽  
Yusuke Atsumi ◽  
Yohei Ito ◽  
...  
Keyword(s):  
Sustained Release ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Sesame Oil ◽  
Chicken Embryos ◽  
Whole Mount ◽  
Phosphate Buffered Saline ◽  
Transfer Study

The aim of the present study was to improve the efficiency of endogenous primordial germ cell (PGC) depletion and to increase the ratio of donor PGCs in the gonads of recipient chicken embryos. A sustained-release emulsion was prepared by emulsifying equal amounts of Ca2+- and Mg2+-free phosphate-buffered saline containing 10% busulfan solubilised in N,N-dimethylformamide and sesame oil, using a filter. Then, 75 μg per 50 μL busulfan sustained-release emulsion was injected into the yolk. To determine the depletion and repopulation of PGCs in the gonads after 6 days incubation, whole-mount immunostaining was performed. The busulfan sustained-release emulsion significantly reduced the number of endogenous PGCs compared with control (P < 0.05). Moreover, the busulfan sustained-release emulsion significantly depleted endogenous PGCs compared with other previously reported busulfan delivery systems (P < 0.05), but with less variation, suggesting that the sustained-release emulsion delivered a consistent amount of busulfan to the developing chicken embryos. The PGC transfer study showed that the proportion of donor PGCs in the gonads of busulfan sustained-release emulsion-treated embryos after 6 days incubation increased 28-fold compared with control. In conclusion, the results demonstrate that exogenous PGCs are capable of migrating and settling in gonads from which endogenous PGCs have been removed using a busulfan sustained-release emulsion.

154 MOLECULAR CHARACTERIZATION OF CAT PRIMORDIAL GERM CELLS

2016 ◽  
Vol 28 (2) ◽  
pp. 207
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
C. Dumas ◽  
G. Wang ◽  
R. A. MacLean ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Transcript Abundance ◽  
Domestic Cat ◽  
Sample Type

As precursors to germline stem cells and gametes, there are many potential applications for primordial germ cells (PGC). Primordial germ cell-like cells have been generated from mouse embryonic stem cells and induced pluripotent stem cells, which subsequently were used to produce functional spermatozoa, oocytes, and healthy offspring (Hayashi et al. 2012 Science 338(6109), 971–975). Applying this approach to generate sperm and oocytes of endangered species is an appealing prospect. Detection of molecular markers associated with PGC is essential to optimizing the process of PGC induction. In the current study, in vitro-derived domestic cat embryos were assessed at various developmental stages to characterise the expression of markers related to the specification process of cat PGC. In vivo-matured, IVF oocytes were cultured until Days 7, 9, and 12 post-insemination. Then, embryos were assessed by RT-qPCR to determine relative transcript abundance of the pluripotency markers NANOG, POU5F1, and SOX2; the epiblast marker DNMT3B; the primitive endoderm marker GATA4; the PGC marker PRDM14; and the germ cell marker VASA; RPS19 was used as the internal reference gene. To validate the qPCR results, fibroblasts served as the negative control cells, whereas spermatogonial stem cells (SSC) served as the positive control cells for GATA4, PRDM14, and VASA. Total mRNA were isolated using the Cells-to-cDNA™ II Kit (Ambion/Thermo Fisher Scientific, Waltham, MA, USA) from either pools of 2 to 6 embryos or ~25 000 fibroblasts/SSC. A minimum of 2 biological replicates for each sample type was analysed, with transcript abundance detected in 2 technical replicates by SYBR Green chemistry. Student’s t-tests were performed on the ΔCts for statistical analysis. PRDM14, specific to the germ cell lineage, was detected as early as Day 7, suggesting the presence of PGC precursor cells. Compared with their levels at Day 7, PRDM14 expression was 0.34-fold lower in SSC (P < 0.05), whereas expression of VASA and GATA4 were 1964-fold and 144-fold higher, respectively (P < 0.05). This seems to emphasise the relative importance of PRDM14 in pre-germ cell stages. In general, all genes analysed were up-regulated from Day 7 to Day 9. This up-regulation was statistically significant for SOX2 and GATA4 (P < 0.05). Relative to that at Day 9, all transcripts were relatively less abundant at Day 12 (P < 0.05 for NANOG, POU5F1, SOX2, DNMT3B, and PRDM14). The data suggest that PGC specification takes place near Day 9, with peak specification activity concluding by Day 12. Although much needs be explored about PGC specification in the cat before applying induction and in vitro germ cell production techniques, these findings represent the first step towards a new potential strategy for preserving endangered and threatened felids.

scholarly journals Purification of mouse primordial germ cells by Nycodenz

Reproduction ◽  
2003 ◽  
pp. 667-675 ◽  
Author(s):  
T Mayanagi ◽  
R Kurosawa ◽  
K Ohnuma ◽  
A Ueyama ◽  
K Ito ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Specific Antibody ◽  
Membrane Surface ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Specific Antigen ◽  
Cell Lineage ◽  
New Method ◽  
Purification Method

Primordial germ cells are important cells for the study of germ cell lineage. It has proved difficult to obtain highly purified primordial germ cells for preparation of a specific antibody. In the present study, a new method for purifying mouse primordial germ cells was developed using a Nycodenz gradient. Furthermore, the polyclonal anti-mouse primordial germ cells IgG derived from mouse primordial germ cells was prepared. As this IgG reacted only with primordial germ cells obtained at day 12.5 after mating, this antibody appeared to recognize the stage-specific antigen of primordial germ cells. One reason that a continuous primordial germ cell marker has not been obtained is because the purity of the primordial germ cells used has been too low to prepare the antibody. This new method represents a significant improvement in the purification of primordial germ cells; it is simpler than previous methods, and produced mouse primordial germ cells with a purity of more than 95%. In addition, the separation reagent Nycodenz is non-toxic and achieved separation of primordial germ cells without attachment of antibodies against the primordial germ cell membrane surface. This new purification method and stage-specific antibody will be useful for the analysis of the mechanisms of primordial germ cell migration.

Male germ cell transplantation: promise and problems

2001 ◽  
Vol 13 (8) ◽  
pp. 609 ◽  
Author(s):  
Fang-Xu Jiang
Keyword(s):  
Germ Cell ◽  
Cell Transplantation ◽  
Germ Cells ◽  
Cell Biology ◽  
Direct Injection ◽  
Primordial Germ Cells ◽  
Rete Testis ◽  
Male Germ Cell ◽  
Seminiferous Tubules ◽  
Germ Cell Transplantation

Male germ cell transplantation is a novel technique in which donor male stem germ cells are surgically transferred to the seminiferous tubules of a recipient testis by direct injection or via the rete testis or efferent duct. All germ cells that are destined to become stem spermatogonia are defined as male stem germ cells, including primordial germ cells from the gonadal ridges, and gonocytes and stem spermatogonia from the testis, all of which are transplantable and capable of undergoing normal spermatogenesis. Xenotransplantation of male germ cells from one species into the testis of another species, including human testicular cells in the mouse, has so far proved to be unsuccessful. However, the immunodeficient mouse testis can support rat spermatogenesis and produce apparently normal rat spermatozoa. The underlying mechanisms remain elusive. The present mini-review will focus on the importance of stem spermatogonial transplantation for testicular stem cell biology and discuss the likelihood of immune rejection after transplantation, which may limit the success of all male germ cell transplantation.

Immunomagnetic Isolation of Primordial Germ Cells and the Establishment of Embryonic Germ Cell Lines in the Mouse

Cloning ◽  
1999 ◽  
Vol 1 (4) ◽  
pp. 217-224 ◽  
Author(s):  
Gabriela Durcova-Hills ◽  
Tomoyuki Tokunaga ◽  
Satoshi Kurosaka ◽  
Manabu Yamaguchi ◽  
Seiya Takahashi ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Lines ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Immunomagnetic Isolation

scholarly journals A Huge Dermoid Cyst in Postmenopausal Women with Third Degree Uterine Prolapse

2013 ◽  
Vol 1 (1) ◽  
pp. 43-44 ◽  
Author(s):  
Deepti Shrivastava ◽  
Anuradha Kakani ◽  
Indradeep Bannerjee
Keyword(s):  
Germ Cell ◽  
Postmenopausal Women ◽  
Dermoid Cyst ◽  
South Asian ◽  
Germ Cells ◽  
Ovarian Tumor ◽  
Rare Case ◽  
Uterine Prolapse ◽  
Primordial Germ Cells ◽  
Germ Cell Tumors

ABSTRACT Germ cell tumors are derived from primordial germ cells of the ovary. Approximately 25 to 30% of all ovarian tumors are of germ cell origin and of these, 95% are benign and only 3 to 4% are malignant. They are seen mostly in women in their second and third decades of life and very rarely in postmenopausal women. There are many reported cases of ovarian tumor in postmenopausal women but a huge dermoid cyst in postmenopausal women causing prolapse uterus is very rare. Here, we are presenting a rare case of large dermoid cyst in a 58-year-old postmenopausal multiparous woman with third degree uterine prolapse. How to cite this article Kakani A, Bannerjee I, Shrivastava D. A Huge Dermoid Cyst in Postmenopausal Women with Third Degree Uterine Prolapse. J South Asian Feder Menopause Soc 2013;1(1):43-44.

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