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Sample records for primary germ layers

  1. Neural crest: The fourth germ layer

    PubMed Central

    Shyamala, K; Yanduri, Sarita; Girish, HC; Murgod, Sanjay

    2015-01-01

    The neural crest cells (NCCs), a transient group of cells that emerges from the dorsal aspect of the neural tube during early vertebrate development has been a fascinating group of cells because of its multipotency, long range migration through embryo and its capacity to generate a prodigious number of differentiated cell types. For these reasons, although derived from the ectoderm, the neural crest (NC) has been called the fourth germ layer. The non neural ectoderm, the neural plate and the underlying mesoderm are needed for the induction and formation of NC cells. Once formed, NC cells start migrating as a wave of cells, moving away from the neuroepithelium and quickly splitting into distinct streams. These migrating NCCs home in to different regions and give rise to plethora of tissues. Umpteen number of signaling molecules are essential for formation, epithelial mesenchymal transition, delamination, migration and localization of NCC. Authors believe that a clear understanding of steps and signals involved in NC formation, migration, etc., may help in understanding the pathogenesis behind cancer metastasis and many other diseases. Hence, we have taken this review to discuss the various aspects of the NC cells. PMID:26604500

  2. Characterizing the mechanical behavior of the zebrafish germ layers

    NASA Astrophysics Data System (ADS)

    Kealhofer, David; Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Lucio, Adam; Campàs, Otger

    Organ morphogenesis and the development of the animal body plan involve complex spatial and temporal control of tissue- and cell-level mechanics. A prime example is the generation of stresses by individual cells to reorganize the tissue. These processes have remained poorly understood due to a lack of techniques to characterize the local constitutive law of the material, which relates local cellular forces to the resulting tissue flows. We have developed a method for quantitative, local in vivo study of material properties in living tissue using magnetic droplet probes. We use this technique to study the material properties of the different zebrafish germ layers using aggregates of zebrafish mesendodermal and ectodermal cells as a model system. These aggregates are ideal for controlled studies of the mechanics of individual germ layers because of the homogeneity of the cell type and the simple spherical geometry. Furthermore, the numerous molecular tools and transgenic lines already developed for this model organism can be applied to these aggregates, allowing us to characterize the contributions of cell cortex tension and cell adhesion to the mechanical properties of the zebrafish germ layers.

  3. Germ layer induction in ESC--following the vertebrate roadmap.

    PubMed

    Smith, Jim; Wardle, Fiona; Loose, Matt; Stanley, Ed; Patient, Roger

    2007-06-01

    Controlled differentiation of pluripotential cells takes place routinely and with great success in developing vertebrate embryos. It therefore makes sense to take note of how this is achieved and use this knowledge to control the differentiation of embryonic stem cells (ESCs). An added advantage is that the differentiated cells resulting from this process in embryos have proven functionality and longevity. This unit reviews what is known about the embryonic signals that drive differentiation in one of the most informative of the vertebrate animal models of development, the amphibian Xenopus laevis. It summarizes their identities and the extent to which their activities are dose-dependent. The unit details what is known about the transcription factor responses to these signals, describing the networks of interactions that they generate. It then discusses the target genes of these transcription factors, the effectors of the differentiated state. Finally, how these same developmental programs operate during germ layer formation in the context of ESC differentiation is summarized.

  4. Spatiotemporal transcriptomics reveals the evolutionary history of the endoderm germ layer.

    PubMed

    Hashimshony, Tamar; Feder, Martin; Levin, Michal; Hall, Brian K; Yanai, Itai

    2015-03-12

    The concept of germ layers has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years (refs 1 - 3). Of the three germ layers, the mesoderm is found in bilaterian animals but is absent in species in the phyla Cnidaria and Ctenophora, which has been taken as evidence that the mesoderm was the final germ layer to evolve. The origin of the ectoderm and endoderm germ layers, however, remains unclear, with models supporting the antecedence of each as well as a simultaneous origin. Here we determine the temporal and spatial components of gene expression spanning embryonic development for all Caenorhabditis elegans genes and use it to determine the evolutionary ages of the germ layers. The gene expression program of the mesoderm is induced after those of the ectoderm and endoderm, thus making it the last germ layer both to evolve and to develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier, and this is also observed in the expression of endoderm orthologues during the embryology of the frog Xenopus tropicalis, the sea anemone Nematostella vectensis and the sponge Amphimedon queenslandica. Querying the phylogenetic ages of specifically expressed genes reveals that the endoderm comprises older genes. Taken together, we propose that the endoderm program dates back to the origin of multicellularity, whereas the ectoderm originated as a secondary germ layer freed from ancestral feeding functions. PMID:25487147

  5. Functions of huntingtin in germ layer specification and organogenesis.

    PubMed

    Nguyen, Giang D; Molero, Aldrin E; Gokhan, Solen; Mehler, Mark F

    2013-01-01

    Huntington's disease (HD) is a neurodegenerative disease caused by abnormal polyglutamine expansion in the huntingtin protein (Htt). Although both Htt and the HD pathogenic mutation (mHtt) are implicated in early developmental events, their individual involvement has not been adequately explored. In order to better define the developmental functions and pathological consequences of the normal and mutant proteins, respectively, we employed embryonic stem cell (ESC) expansion, differentiation and induction experiments using huntingtin knock-out (KO) and mutant huntingtin knock-in (Q111) mouse ESC lines. In KO ESCs, we observed impairments in the spontaneous specification and survival of ectodermal and mesodermal lineages during embryoid body formation and under inductive conditions using retinoic acid and Wnt3A, respectively. Ablation of BAX improves cell survival, but failed to correct defects in germ layer specification. In addition, we observed ensuing impairments in the specification and maturation of neural, hepatic, pancreatic and cardiomyocyte lineages. These developmental deficits occurred in concert with alterations in Notch, Hes1 and STAT3 signaling pathways. Moreover, in Q111 ESCs, we observed differential developmental stage-specific alterations in lineage specification and maturation. We also observed changes in Notch/STAT3 expression and activation. Our observations underscore essential roles of Htt in the specification of ectoderm, endoderm and mesoderm, in the specification of neural and non-neural organ-specific lineages, as well as cell survival during early embryogenesis. Remarkably, these developmental events are differentially deregulated by mHtt, raising the possibility that HD-associated early developmental impairments may contribute not only to region-specific neurodegeneration, but also to non-neural co-morbidities.

  6. Functions of Huntingtin in Germ Layer Specification and Organogenesis

    PubMed Central

    Nguyen, Giang D.; Molero, Aldrin E.; Gokhan, Solen; Mehler, Mark F.

    2013-01-01

    Huntington’s disease (HD) is a neurodegenerative disease caused by abnormal polyglutamine expansion in the huntingtin protein (Htt). Although both Htt and the HD pathogenic mutation (mHtt) are implicated in early developmental events, their individual involvement has not been adequately explored. In order to better define the developmental functions and pathological consequences of the normal and mutant proteins, respectively, we employed embryonic stem cell (ESC) expansion, differentiation and induction experiments using huntingtin knock-out (KO) and mutant huntingtin knock-in (Q111) mouse ESC lines. In KO ESCs, we observed impairments in the spontaneous specification and survival of ectodermal and mesodermal lineages during embryoid body formation and under inductive conditions using retinoic acid and Wnt3A, respectively. Ablation of BAX improves cell survival, but failed to correct defects in germ layer specification. In addition, we observed ensuing impairments in the specification and maturation of neural, hepatic, pancreatic and cardiomyocyte lineages. These developmental deficits occurred in concert with alterations in Notch, Hes1 and STAT3 signaling pathways. Moreover, in Q111 ESCs, we observed differential developmental stage-specific alterations in lineage specification and maturation. We also observed changes in Notch/STAT3 expression and activation. Our observations underscore essential roles of Htt in the specification of ectoderm, endoderm and mesoderm, in the specification of neural and non-neural organ-specific lineages, as well as cell survival during early embryogenesis. Remarkably, these developmental events are differentially deregulated by mHtt, raising the possibility that HD-associated early developmental impairments may contribute not only to region-specific neurodegeneration, but also to non-neural co-morbidities. PMID:23967334

  7. Primary Malignant Mixed Germ Cell Tumour with Squamous Cell Carcinoma of the Mandible; A Rare Entity

    PubMed Central

    Paul, Arun; Parmar, Harshad; Chacko, Rabin

    2015-01-01

    Germ cell Tumours (GCT) are neoplasm derived from germ cells. GCT usually occurs inside the gonads. Extragonadal GCT’s are rare. Most common GCT associated with head and neck region are the teratomas. Of the few teratomas found in the head and neck, malignant transformation of a teratomatous element is very uncommon, and primary bone involvement within the head and neck is even rare. We present a case of primary malignant mixed germ cell Tumour involving the mandible, the present case presented malignant transformation of the epithelial component showing foci of squamous cell carcinoma within the GCT. PMID:26266228

  8. The influence of scaffold elasticity on germ layer specification of human embryonic stem cells.

    PubMed

    Zoldan, Janet; Karagiannis, Emmanouil D; Lee, Christopher Y; Anderson, Daniel G; Langer, Robert; Levenberg, Shulamit

    2011-12-01

    Mechanical forces are critical to embryogenesis, specifically, in the lineage-specification gastrulation phase, whereupon the embryo is transformed from a simple spherical ball of cells to a multi-layered organism, containing properly organized endoderm, mesoderm, and ectoderm germ layers. Several reports have proposed that such directed and coordinated movements of large cell collectives are driven by cellular responses to cell deformations and cell-generated forces. To better understand these environmental-induced cell changes, we have modeled the germ layer formation process by culturing human embryonic stem cells (hESCs) on three dimensional (3D) scaffolds with stiffness engineered to model that found in specific germ layers. We show that differentiation to each germ layer was promoted by a different stiffness threshold of the scaffolds, reminiscent of the forces exerted during the gastrulation process. The overall results suggest that three dimensional (3D) scaffolds can recapitulate the mechanical stimuli required for directing hESC differentiation and that these stimuli can play a significant role in determining hESC fate. PMID:21963156

  9. DNA Methylation Profiling of Embryonic Stem Cell Differentiation into the Three Germ Layers

    PubMed Central

    Isagawa, Takayuki; Nagae, Genta; Shiraki, Nobuaki; Fujita, Takanori; Sato, Noriko; Ishikawa, Shumpei; Kume, Shoen; Aburatani, Hiroyuki

    2011-01-01

    Embryogenesis is tightly regulated by multiple levels of epigenetic regulation such as DNA methylation, histone modification, and chromatin remodeling. DNA methylation patterns are erased in primordial germ cells and in the interval immediately following fertilization. Subsequent developmental reprogramming occurs by de novo methylation and demethylation. Variance in DNA methylation patterns between different cell types is not well understood. Here, using methylated DNA immunoprecipitation and tiling array technology, we have comprehensively analyzed DNA methylation patterns at proximal promoter regions in mouse embryonic stem (ES) cells, ES cell-derived early germ layers (ectoderm, endoderm and mesoderm) and four adult tissues (brain, liver, skeletal muscle and sperm). Most of the methylated regions are methylated across all three germ layers and in the three adult somatic tissues. This commonly methylated gene set is enriched in germ cell-associated genes that are generally transcriptionally inactive in somatic cells. We also compared DNA methylation patterns by global mapping of histone H3 lysine 4/27 trimethylation, and found that gain of DNA methylation correlates with loss of histone H3 lysine 4 trimethylation. Our combined findings indicate that differentiation of ES cells into the three germ layers is accompanied by an increased number of commonly methylated DNA regions and that these tissue-specific alterations in methylation occur for only a small number of genes. DNA methylation at the proximal promoter regions of commonly methylated genes thus appears to be an irreversible mark which functions to fix somatic lineage by repressing the transcription of germ cell-specific genes. PMID:22016810

  10. Germ layer formation during Xenopus embryogenesis: the balance between pluripotency and differentiation.

    PubMed

    Cao, Ying

    2015-04-01

    The African clawed frog, Xenopus laevis, has long been a model animal for the studies in the fields of animal cloning, developmental biology, biochemistry, cell biology, and physiology. With the aid of Xenopus, major molecular mechanisms that are involved in embryonic development have been understood. Germ layer formation is the first event of embryonic cellular differentiation, which is induced by a few key maternal factors and subsequently by zygotic signals. Meanwhile, another type of signals, the pluripotency factors in ES cells, which maintain the undifferentiated state, are also present during early embryonic cells. In this review, the functions of the pluripotency factors during Xenopus germ layer formation and the regulatory relationship between the signals that promote differentiation and pluripotency factors are discussed.

  11. Quantitative differences in tissue surface tension influence zebrafish germ layer positioning

    PubMed Central

    Schötz, Eva-Maria; Burdine, Rebecca D.; Jülicher, Frank; Steinberg, Malcolm S.; Heisenberg, Carl-Philipp; Foty, Ramsey A.

    2008-01-01

    This study provides direct functional evidence that differential adhesion, measurable as quantitative differences in tissue surface tension, influences spatial positioning between zebrafish germ layer tissues. We show that embryonic ectodermal and mesendodermal tissues generated by mRNA-overexpression behave on long-time scales like immiscible fluids. When mixed in hanging drop culture, their cells segregate into discrete phases with ectoderm adopting an internal position relative to the mesendoderm. The position adopted directly correlates with differences in tissue surface tension. We also show that germ layer tissues from untreated embryos, when extirpated and placed in culture, adopt a configuration similar to those of their mRNA-overexpressing counterparts. Down-regulating E-cadherin expression in the ectoderm leads to reduced surface tension and results in phase reversal with E-cadherin-depleted ectoderm cells now adopting an external position relative to the mesendoderm. These results show that in vitro cell sorting of zebrafish mesendoderm and ectoderm tissues is specified by tissue interfacial tensions. We perform a mathematical analysis indicating that tissue interfacial tension between actively motile cells contributes to the spatial organization and dynamics of these zebrafish germ layers in vivo. PMID:19404452

  12. Origin of germ cells and formation of new primary follicles in adult human ovaries

    PubMed Central

    Bukovsky, Antonin; Caudle, Michael R; Svetlikova, Marta; Upadhyaya, Nirmala B

    2004-01-01

    Recent reports indicate that functional mouse oocytes and sperm can be derived in vitro from somatic cell lines. We hypothesize that in adult human ovaries, mesenchymal cells in the tunica albuginea (TA) are bipotent progenitors with a commitment for both primitive granulosa and germ cells. We investigated ovaries of twelve adult women (mean age 32.8 ± 4.1 SD, range 27–38 years) by single, double, and triple color immunohistochemistry. We show that cytokeratin (CK)+ mesenchymal cells in ovarian TA differentiate into surface epithelium (SE) cells by a mesenchymal-epithelial transition. Segments of SE directly associated with ovarian cortex are overgrown by TA, forming solid epithelial cords, which fragment into small (20 micron) epithelial nests descending into the lower ovarian cortex, before assembling with zona pellucida (ZP)+ oocytes. Germ cells can originate from SE cells which cover the TA. Small (10 micron) germ-like cells showing PS1 meiotically expressed oocyte carbohydrate protein are derived from SE cells via asymmetric division. They show nuclear MAPK immunoexpression, subsequently divide symmetrically, and enter adjacent cortical vessels. During vascular transport, the putative germ cells increase to oocyte size, and are picked-up by epithelial nests associated with the vessels. During follicle formation, extensions of granulosa cells enter the oocyte cytoplasm, forming a single paranuclear CK+ Balbiani body supplying all the mitochondria of the oocyte. In the ovarian medulla, occasional vessels show an accumulation of ZP+ oocytes (25–30 microns) or their remnants, suggesting that some oocytes degenerate. In contrast to males, adult human female gonads do not preserve germline type stem cells. This study expands our previous observations on the formation of germ cells in adult human ovaries. Differentiation of primitive granulosa and germ cells from the bipotent mesenchymal cell precursors of TA in adult human ovaries represents a most

  13. Clinicopathological and immunohistochemical features of primary central nervous system germ cell tumors: a 24-years experience.

    PubMed

    Gao, Yuping; Jiang, Jiyao; Liu, Qiang

    2014-01-01

    Primary central nervous system (CNS) germ cell tumors (GCTs) are a rare heterogeneous group of lesions, which the clinicopathological features have a marked degree of heterogeneity comparing with that of gonadal GCTs. Accurately diagnosing CNS GCTs might be extremely difficult and requires immunohistochemical verification. This study was to investigate the biological feature of CNS GCTs and diagnostic value of immunohistochemical markers OCT3/4, C-kit, PLAP, and CD30 in CNS GCTs. A retrospective study was performed on 34 patients with CNS germ cell tumors between 1990 and 2014. 34 CNS GCTs account for 9.2% of all primary CNS neoplasms. The sellar region (35.3%) and pineal gland (17.6%) were the most common sites of intracranial GCTs. Hydrocephalus (82.4%) and diplopia (46.9%) were the two most common clinical presentations. The most common histological subtypes were germinoma (67.6%). PLAP, c-kit, OCT3/4 were highly expressed in gernimomas. CD30 and CK AE1/3 stainings were positive in embryonal carcinoma. Yolk sac tumor component showed positive staining for AFP and CK AE1/3. β-HCG staining was positive in choriocarcinoma and STGC. Patients with mature teratomas and germinomas had a better prognosis (a 5-year survival rate) than those with embryonal carcinoma and choriocarcinoma (a 5-year survival rates were 0). Our finding suggest that the incidences of primary CNS GCTs are higher in South China than in the West, but mixed GCTs are uncommon in our study. The judicious use of a panel of selected markers is helpful in diagnosing and predicting the prognosis for CNS GCTs.

  14. EphrinB/EphB Signaling Controls Embryonic Germ Layer Separation by Contact-Induced Cell Detachment

    PubMed Central

    Rohani, Nazanin; Canty, Laura; Luu, Olivia

    2011-01-01

    Background The primordial organization of the metazoan body is achieved during gastrulation by the establishment of the germ layers. Adhesion differences between ectoderm, mesoderm, and endoderm cells could in principle be sufficient to maintain germ layer integrity and prevent intermixing. However, in organisms as diverse as fly, fish, or amphibian, the ectoderm-mesoderm boundary not only keeps these germ layers separated, but the ectoderm also serves as substratum for mesoderm migration, and the boundary must be compatible with repeated cell attachment and detachment. Principal Findings We show that localized detachment resulting from contact-induced signals at the boundary is at the core of ectoderm-mesoderm segregation. Cells alternate between adhesion and detachment, and detachment requires ephrinB/EphB signaling. Multiple ephrinB ligands and EphB receptors are expressed on each side of the boundary, and tissue separation depends on forward signaling across the boundary in both directions, involving partially redundant ligands and receptors and activation of Rac and RhoA. Conclusion This mechanism differs from a simple differential adhesion process of germ layer formation. Instead, it involves localized responses to signals exchanged at the tissue boundary and an attachment/detachment cycle which allows for cell migration across a cellular substratum. PMID:21390298

  15. Fluorescent imaging of endothelial glycocalyx layer with wheat germ agglutinin using intravital microscopy.

    PubMed

    Kataoka, Hanae; Ushiyama, Akira; Kawakami, Hayato; Akimoto, Yoshihiro; Matsubara, Sachie; Iijima, Takehiko

    2016-01-01

    Endothelial glycocalyx (GCX) is located on the apical surface of vascular endothelial cells and is composed of a negatively-charged network of proteoglycans and glycoproteins. The GCX plays an important role in maintaining the integrity of vascular walls and preventing leakage of plasma. Therefore, degradation of the GCX is believed to lead to pathological leakage of plasma. Because the GCX is a very thin layer, its ultrastructural image has been demonstrated on electron microscope. To explore the function of the GCX, it should be visualized by a microscope in vivo. Thus, we developed in vivo visualization technique of the GCX under fluorescence microscopy using a mouse dorsal skinfold chamber (DSC) model. To label and visualize the GCX, we used fluorescein isothiocyanate (FITC)-labeled lectin, which has a high specificity for sugar moieties. We examined the affinity of the different lectins to epivascular regions under an intravital fluorescent microscope. Among seven different lectins we examined, FITC labeled Triticum vulgaris (wheat germ) agglutinin (WGA) delineated the GCX most clearly. Binding of WGA to the GCX was inhibited by chitin hydrolysate, which contained WGA-binding polysaccharide chains. Furthermore, the septic condition attenuated this structure, suggesting structural degradation of endothelial GCX layer. In conclusion, FITC-labeled WGA lectin enabled visualization of endothelial GCX under in vivo fluorescence microscopy.

  16. Tetraploid Embryonic Stem Cells Maintain Pluripotency and Differentiation Potency into Three Germ Layers

    PubMed Central

    Imai, Hiroyuki; Kano, Kiyoshi; Fujii, Wataru; Takasawa, Ken; Wakitani, Shoichi; Hiyama, Masato; Nishino, Koichiro; Kusakabe, Ken Takeshi; Kiso, Yasuo

    2015-01-01

    Polyploid amphibians and fishes occur naturally in nature, while polyploid mammals do not. For example, tetraploid mouse embryos normally develop into blastocysts, but exhibit abnormalities and die soon after implantation. Thus, polyploidization is thought to be harmful during early mammalian development. However, the mechanisms through which polyploidization disrupts development are still poorly understood. In this study, we aimed to elucidate how genome duplication affects early mammalian development. To this end, we established tetraploid embryonic stem cells (TESCs) produced from the inner cell masses of tetraploid blastocysts using electrofusion of two-cell embryos in mice and studied the developmental potential of TESCs. We demonstrated that TESCs possessed essential pluripotency and differentiation potency to form teratomas, which differentiated into the three germ layers, including diploid embryonic stem cells. TESCs also contributed to the inner cell masses in aggregated chimeric blastocysts, despite the observation that tetraploid embryos fail in normal development soon after implantation in mice. In TESCs, stability after several passages, colony morphology, and alkaline phosphatase activity were similar to those of diploid ESCs. TESCs also exhibited sufficient expression and localization of pluripotent markers and retained the normal epigenetic status of relevant reprogramming factors. TESCs proliferated at a slower rate than ESCs, indicating that the difference in genomic dosage was responsible for the different growth rates. Thus, our findings suggested that mouse ESCs maintained intrinsic pluripotency and differentiation potential despite tetraploidization, providing insights into our understanding of developmental elimination in polyploid mammals. PMID:26091100

  17. Symmetry breaking, germ layer specification and axial organisation in aggregates of mouse embryonic stem cells.

    PubMed

    van den Brink, Susanne C; Baillie-Johnson, Peter; Balayo, Tina; Hadjantonakis, Anna-Katerina; Nowotschin, Sonja; Turner, David A; Martinez Arias, Alfonso

    2014-11-01

    Mouse embryonic stem cells (mESCs) are clonal populations derived from preimplantation mouse embryos that can be propagated in vitro and, when placed into blastocysts, contribute to all tissues of the embryo and integrate into the normal morphogenetic processes, i.e. they are pluripotent. However, although they can be steered to differentiate in vitro into all cell types of the organism, they cannot organise themselves into structures that resemble embryos. When aggregated into embryoid bodies they develop disorganised masses of different cell types with little spatial coherence. An exception to this rule is the emergence of retinas and anterior cortex-like structures under minimal culture conditions. These structures emerge from the cultures without any axial organisation. Here, we report that small aggregates of mESCs, of about 300 cells, self-organise into polarised structures that exhibit collective behaviours reminiscent of those that cells exhibit in early mouse embryos, including symmetry breaking, axial organisation, germ layer specification and cell behaviour, as well as axis elongation. The responses are signal specific and uncouple processes that in the embryo are tightly associated, such as specification of the anteroposterior axis and anterior neural development, or endoderm specification and axial elongation. We discuss the meaning and implications of these observations and the potential uses of these structures which, because of their behaviour, we suggest to call 'gastruloids'.

  18. Primary malignant mediastinal germ cell tumours: improved prognosis with platinum-based chemotherapy and surgery.

    PubMed Central

    Childs, W. J.; Goldstraw, P.; Nicholls, J. E.; Dearnaley, D. P.; Horwich, A.

    1993-01-01

    A retrospective analysis was performed of 18 patients with primary malignant germ cell tumours of the mediastinum treated with platinum-based chemotherapy between 1977 and 1990. All seven patients with pure seminoma were treated initially with chemotherapy and four of these patients received additional mediastinal radiotherapy. Only one patient relapsed; his initial therapy had included radiotherapy and single-agent carboplatin and he was successfully salvaged with combination chemotherapy. With a follow-up of 11 to 117 months (median 41 months) all seven patients with seminoma remain alive and disease free giving an overall survival of 100%. Eleven patients had malignant non seminoma; following chemotherapy eight of these had elective surgical resection of residual mediastinal masses. Complete remission was achieved in nine (82%) patients, however, one of these patients died from bleomycin pneumonitis. With a follow-up of 12 to 113 months (median 55 months) eight of 11 (73%) patients with malignant mediastinal teratoma remain alive and disease free. PMID:8494705

  19. An ancient role for nuclear beta-catenin in the evolution of axial polarity and germ layer segregation

    NASA Technical Reports Server (NTRS)

    Wikramanayake, Athula H.; Hong, Melanie; Lee, Patricia N.; Pang, Kevin; Byrum, Christine A.; Bince, Joanna M.; Xu, Ronghui; Martindale, Mark Q.

    2003-01-01

    The human oncogene beta-catenin is a bifunctional protein with critical roles in both cell adhesion and transcriptional regulation in the Wnt pathway. Wnt/beta-catenin signalling has been implicated in developmental processes as diverse as elaboration of embryonic polarity, formation of germ layers, neural patterning, spindle orientation and gap junction communication, but the ancestral function of beta-catenin remains unclear. In many animal embryos, activation of beta-catenin signalling occurs in blastomeres that mark the site of gastrulation and endomesoderm formation, raising the possibility that asymmetric activation of beta-catenin signalling specified embryonic polarity and segregated germ layers in the common ancestor of bilaterally symmetrical animals. To test whether nuclear translocation of beta-catenin is involved in axial identity and/or germ layer formation in 'pre-bilaterians', we examined the in vivo distribution, stability and function of beta-catenin protein in embryos of the sea anemone Nematostella vectensis (Cnidaria, Anthozoa). Here we show that N. vectensis beta-catenin is differentially stabilized along the oral-aboral axis, translocated into nuclei in cells at the site of gastrulation and used to specify entoderm, indicating an evolutionarily ancient role for this protein in early pattern formation.

  20. Redeployment of germ layers related TFs shows regionalized expression during two non-embryonic developments.

    PubMed

    Ricci, Lorenzo; Cabrera, Fabien; Lotito, Sonia; Tiozzo, Stefano

    2016-08-01

    In all non-vertebrate metazoan phyla, species that evolved non-embryonic developmental pathways as means of propagation or regeneration can be found. In this context, new bodies arise through asexual reproduction processes (such as budding) or whole body regeneration, that lack the familiar temporal and spatial cues classically associated with embryogenesis, like maternal determinants, or gastrulation. The molecular mechanisms underlying those non-embryonic developments (i.e., regeneration and asexual reproduction), and their relationship to those deployed during embryogenesis are poorly understood. We have addressed this question in the colonial ascidian Botryllus schlosseri, which undergoes an asexual reproductive process via palleal budding (PB), as well as a whole body regeneration by vascular budding (VB). We identified early regenerative structures during VB and then followed the fate of differentiating tissues during both non-embryonic developments (PB and VB) by monitoring the expression of genes known to play key functions in germ layer specification with well conserved expression patterns in solitary ascidian embryogenesis. The expression patterns of FoxA1, GATAa, GATAb, Otx, Bra, Gsc and Tbx2/3 were analysed during both PB and VB. We found that the majority of these transcription factors were expressed during both non-embryonic developmental processes, revealing a regionalization of the palleal and vascular buds. Knockdown of GATAa by siRNA in palleal buds confirmed that preventing the correct development of one of these regions blocks further tissue specification. Our results indicate that during both normal and injury-induced budding, a similar alternative developmental program operates via early commitment of epithelial regions.

  1. Redeployment of germ layers related TFs shows regionalized expression during two non-embryonic developments.

    PubMed

    Ricci, Lorenzo; Cabrera, Fabien; Lotito, Sonia; Tiozzo, Stefano

    2016-08-01

    In all non-vertebrate metazoan phyla, species that evolved non-embryonic developmental pathways as means of propagation or regeneration can be found. In this context, new bodies arise through asexual reproduction processes (such as budding) or whole body regeneration, that lack the familiar temporal and spatial cues classically associated with embryogenesis, like maternal determinants, or gastrulation. The molecular mechanisms underlying those non-embryonic developments (i.e., regeneration and asexual reproduction), and their relationship to those deployed during embryogenesis are poorly understood. We have addressed this question in the colonial ascidian Botryllus schlosseri, which undergoes an asexual reproductive process via palleal budding (PB), as well as a whole body regeneration by vascular budding (VB). We identified early regenerative structures during VB and then followed the fate of differentiating tissues during both non-embryonic developments (PB and VB) by monitoring the expression of genes known to play key functions in germ layer specification with well conserved expression patterns in solitary ascidian embryogenesis. The expression patterns of FoxA1, GATAa, GATAb, Otx, Bra, Gsc and Tbx2/3 were analysed during both PB and VB. We found that the majority of these transcription factors were expressed during both non-embryonic developmental processes, revealing a regionalization of the palleal and vascular buds. Knockdown of GATAa by siRNA in palleal buds confirmed that preventing the correct development of one of these regions blocks further tissue specification. Our results indicate that during both normal and injury-induced budding, a similar alternative developmental program operates via early commitment of epithelial regions. PMID:27208394

  2. Disease characteristics and survival outcomes of extragonadal primary germ cell tumour in two Canadian tertiary cancer centres

    PubMed Central

    Ko, Jenny J.; Asif, Tehmina; Li, Haocheng; Alimohamed, Nimira; Nguyen, Phuong Thao; Heng, Daniel Y.C.

    2016-01-01

    Introduction: Extragonadal germ cell tumours (EGCTs) are a heterogeneous group with distinct natural history and responses to treatment modalities. We sought to evaluate characteristics and survival outcomes in men with EGCTs. Methods: We performed a retrospective analysis on a consecutive list of men diagnosed with EGCT in two Albertan cancer centres between 1990 and 2013. Demographic characteristics and outcomes, stratified by primary site, were evaluated. Results: Sixty-nine cases were identified. The median age was 29 (range 15–76) and 48 cases (70%) were non-seminomatous. Twenty-four (35%) belonged to International Germ Cell Cancer Collaborative Group (IGCCCG) favourable risk group, 14 (20%) to intermediate, and 31 (45%) to poor. Thirty (43%) had mediastinal primary (MPs); 29 were treated with first-line bleomycin, etopo-side, and cisplatin (BEP). Seventeen (57%) relapses occurred, of which three patients achieved long-term survival. Seventeen (25%) had a central nervous system (CNS) primary, with eight (47%) classic germinoma. Seven (41%) received primary chemotherapy alone; 5 (29%) received primary radiotherapy alone, and 5 (29%) received both. Nineteen (28%) had a retroperitoneal primary (RPs) and received first-line chemotherapy; all but two received BEP and eight (42%) had surgical resection. Three (5%) had other or unknown primary. Five-year overall survival (OS) and disease-free survival for all patients were 56% and 44%, respectively; for MPs, 44% and 34%; for CNS primary, 76% and 53%; for RPs, 58% and 53%. Factors that correlated with decreased OS were elevated alpha fetoprotein (AFP) (p<0.001) or human chorionic gonadotropin (HCG) (p=0.001), lactate dehydrogenase (LDH) levels (p=0.028), bone metastasis (p<0.001), lung metastasis (p<0.001), and IGCCCG poor risk (p=0.001). Conclusions: EGCT is a rare, but important subset of GCT. Patients with EGCTs, despite aggressive treatments, still have poorer outcomes than gonadal primary. PMID:27790297

  3. A novel somatic MAPK1 mutation in primary ovarian mixed germ cell tumors.

    PubMed

    Zou, Yang; Deng, Wei; Wang, Feng; Yu, Xiao-Hong; Liu, Fa-Ying; Yang, Bi-Cheng; Huang, Mei-Zhen; Guo, Jiu-Bai; Xie, Qiu-Hua; He, Ming; Huang, Ou-Ping

    2016-02-01

    A recent exome-sequencing study revealed prevalent mitogen-activated protein kinase 1 (MAPK1) p.E322K mutation in cervical carcinoma. It remains largely unknown whether ovarian carcinomas also harbor MAPK1 mutations. As paralogous gene mutations co‑occur frequently in human malignancies, we analyzed here a total of 263 ovarian carcinomas for the presence of MAPK1 and paralogous MAPK3 mutations by DNA sequencing. A previously unreported MAPK1 p.D321N somatic mutation was identified in 2 out of 18 (11.1%) ovarian mixed germ cell tumors, while no other MAPK1 or MAPK3 mutation was detected in our samples. Of note, OCC‑115, the MAPK1‑mutated sample with bilateral cancerous ovaries affected, harbored MAPK1 mutation in the right ovary while retained the left ovary intact, implicating that the genetic alterations underlying ovarian mixed germ cell tumor may be different, even in patients with similar genetic backgrounds and tumor microenvironments. The results of evolutionary conservation and protein structure modeling analysis implicated that MAPK1 p.D321N mutation may be pathogenic. Additionally, mutations in protein phosphatase 2 regulatory subunit α (PPP2R1A), ring finger protein 43 (RNF43), DNA directed polymerase ε (POLE1), ribonuclease type III (DICER1), CCCTC‑binding factor (CTCF), ribosomal protein L22 (RPL22), DNA methyltransferase 3α (DNMT3A), transformation/transcription domain‑associated protein (TRRAP), isocitrate dehydrogenase (IDH)1 and IDH2 were not detected in ovarian mixed germ cell tumors, implicating these genetic alterations may be not associated with MAPK1 mutation in the development of this malignancy. The present study identified a previously unreported MAPK1 mutation in ovarian mixed germ cell tumors for the first time, and this mutation may be actively involved in the tumorigenesis of this disease.

  4. YKL-40 is differentially expressed in human embryonic stem cells and in cell progeny of the three germ layers.

    PubMed

    Brøchner, Christian B; Johansen, Julia S; Larsen, Lars A; Bak, Mads; Mikkelsen, Hanne B; Byskov, Anne Grete; Andersen, Claus Yding; Møllgård, Kjeld

    2012-03-01

    The secreted glycoprotein YKL-40 participates in cell differentiation, inflammation, and cancer progression. High YKL-40 expression is reported during early human development, but its functions are unknown. Six human embryonic stem cell (hESC) lines were cultured in an atmosphere of low or high oxygen tension, in culture medium with or without basic fibroblast growth factor, and on feeder layers comprising mouse embryonic fibroblasts or human foreskin fibroblasts to evaluate whether hESCs and their progeny produced YKL-40 and to characterize YKL-40 expression during differentiation. Secreted YKL-40 protein and YKL-40 mRNA expression were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative RT-PCR. Serial-sectioned colonies were stained for YKL-40 protein and for pluripotent hESC (OCT4, NANOG) and germ layer (HNF-3β, PDX1, CD34, p63, nestin, PAX6) markers. Double-labeling showed YKL-40 expression in OCT4-positive hESCs, PAX6-positive neuroectodermal cells, and HNF-3β-positive endodermal cells. The differentiating progeny showed strong YKL-40 expression. Abrupt transition between YKL-40 and OCT4-positive hESCs and YKL-40-positive ecto- and neuroectodermal lineages was observed within the same epithelial-like layer. YKL-40-positive cells within deeper layers lacked contact with OCT4-positive cells. YKL-40 may be important in initial cell differentiation from hESCs toward ectoderm and neuroectoderm, with retained epithelial morphology, whereas later differentiation into endoderm and mesoderm involves a transition into the deeper layers of the colony.

  5. Primary CNS germ cell tumors in Japan and the United States: an analysis of 4 tumor registries.

    PubMed

    McCarthy, Bridget J; Shibui, Soichiro; Kayama, Takamasa; Miyaoka, Etsuo; Narita, Yoshitaka; Murakami, Michiko; Matsuda, Ayako; Matsuda, Tomohiro; Sobue, Tomotaka; Palis, Bryan E; Dolecek, Therese A; Kruchko, Carol; Engelhard, Herbert H; Villano, J Lee

    2012-09-01

    Intracranial germ cell tumors (GCTs) are relatively rare. Their incidence has been considered to be higher in East Asia than in the United States. This study estimates the incidence of CNS GCTs in Japan and the United States, investigates gender discrepancies in each country, and describes treatment outcomes. Data on primary CNS GCTs from 4 databases were utilized: population-based malignant incidence data from (1) the Japan Cancer Surveillance Research Group (2004-2006; 14 registries), malignant and nonmalignant incidence data from (2) the Surveillance, Epidemiology, and End Results Program (2004-2008; 17 registries), and hospital-based observed survival data from (3) the Brain Tumor Registry of Japan (1984-2000) and (4) the US National Cancer Data Base (1990-2003). Incidence rates per 100 000 for malignant GCTs were not statistically significantly different between Japan (males = 0.143, females = 0.046) and the United States (males = 0.118, females = 0.030). The malignant incidence-rate ratio was higher for pineal GCTs versus nonpineal (ie, the rest of the brain) GCTs in Japan (11.5:1 vs 1.9:1, respectively) and the United States (16.0:1 vs 1.7:1, respectively). In general, 5-year survival estimates were high: over 75% for all GCTs, and over 81% for germinomas, regardless of the type of treatment in either Japan or the United States. The incidence of primary GCTs is similar between Japan and the United States and has the same gender-based patterns by location. High rates of survival were observed in both countries.

  6. Non-primary layering in some Adirondack orthogneisses

    SciTech Connect

    Levy, R.; McLelland, J.; Ritter, A. . Geology Dept.)

    1993-03-01

    Metamorphic, as opposed to primary, layering has been shown to be important in many tectonites. Within orthogneisses additional types of non-primary layering are common and have important genetic implications. Here the authors cite three Adirondack examples. (1) Hyde School Gneiss of the Adirondack Lowlands contains semi-continuous layers of foliated amphibolite arranged parallel to contacts and early foliation and disrupted by pegmatitic, alaskitic, and tonalitic host rock. Layering appears to be the result of penetration of amphibolite by granitoid magma first along extensional fractures and then parallel to foliation. Intrusion is envisaged to take place in active shear zones initially occupied by foliated amphibolite that is subsequently penetrated parallel to foliation by granitoids. (2) South of Elizabethtown foliated, isoclinally folded gabbroic anorthosite is well layered with garnetiferous amphibolite, quartz-feldspar gneiss, and calcsilicate. Because of rock composition, the layering cannot be due to metavolcanic sequences nor can disruption be attributed to partial melting. A satisfactory interpretation is that gabbroic anorthosite intruded mafic and carbonate-rich rocks in lit-par-lit fashion. (3) North of Speculator a garnetiferous amphibolite/gabbro has been intruded by granite now containing xenoliths, some with ophitic opx. Much of the layering in the granite consists of clots of plagioclase, garnet, pyroxene (chloritized) arranged in parallel. These are interpreted as small xenoliths of garnetiferous amphibolite/gabbro entrained into the granitic magma and strung out in the direction of flow. These examples provide further evidence that layering can develop during magmatic emplacement and need not represent primary stratification. Assignment of a primary origin to such layering necessarily results in misinterpretation of geologic history.

  7. SOX9 accelerates ESC differentiation to three germ layer lineages by repressing SOX2 expression through P21 (WAF1/CIP1).

    PubMed

    Yamamizu, Kohei; Schlessinger, David; Ko, Minoru S H

    2014-11-01

    Upon removal of culture conditions that maintain an undifferentiated state, mouse embryonic stem cells (ESCs) differentiate into various cell types. Differentiation can be facilitated by forced expression of certain transcription factors (TFs), each of which can generally specify a particular developmental lineage. We previously established 137 mouse ESC lines, each of which carried a doxycycline-controllable TF. Among them, Sox9 has unique capacity: its forced expression accelerates differentiation of mouse ESCs into cells of all three germ layers. With the additional use of specific culture conditions, overexpression of Sox9 facilitated the generation of endothelial cells, hepatocytes and neurons from ESCs. Furthermore, Sox9 action increases formation of p21 (WAF1/CIP1), which then binds to the SRR2 enhancer of pluripotency marker Sox2 and inhibits its expression. Knockdown of p21 abolishes inhibition of Sox2 and Sox9-accelerated differentiation, and reduction of Sox2 2 days after the beginning of ESC differentiation can comparably accelerate mouse ESC formation of cells of three germ layers. These data implicate the involvement of the p21-Sox2 pathway in the mechanism of accelerated ESC differentiation by Sox9 overexpression. The molecular cascade could be among the first steps to program ESC differentiation.

  8. Trainee Primary Teachers' Ideas about the Ozone Layer.

    ERIC Educational Resources Information Center

    Boyes, Edward; And Others

    1995-01-01

    Survey results reveal trainee primary teachers are well informed about the nature and location of the ozone layer and appreciated that it screens the earth from ultraviolet (UV) rays, although some thought that it protects the earth from acid rain. Identifies themes in students' thinking and groups of students with different concepts. (LZ)

  9. ST8SIA4-Dependent Polysialylation is Part of a Developmental Program Required for Germ Layer Formation from Human Pluripotent Stem Cells.

    PubMed

    Berger, Ryan P; Sun, Yu Hua; Kulik, Michael; Lee, Jin Kyu; Nairn, Alison V; Moremen, Kelley W; Pierce, Michael; Dalton, Stephen

    2016-07-01

    Polysialic acid (PSA) is a carbohydrate polymer of repeating α-2,8 sialic acid residues that decorates multiple targets, including neural cell adhesion molecule (NCAM). PST and STX encode the two enzymes responsible for PSA modification of target proteins in mammalian cells, but despite widespread polysialylation in embryonic development, the majority of studies have focused strictly on the role of PSA in neurogenesis. Using human pluripotent stem cells (hPSCs), we have revisited the developmental role of PST and STX and show that early progenitors of the three embryonic germ layers are polysialylated on their cell surface. Changes in polysialylation can be attributed to lineage-specific expression of polysialyltransferase genes; PST is elevated in endoderm and mesoderm, while STX is elevated in ectoderm. In hPSCs, PST and STX genes are epigenetically marked by overlapping domains of H3K27 and H3K4 trimethylation, indicating that they are held in a "developmentally-primed" state. Activation of PST transcription during early mesendoderm differentiation is under control of the T-Goosecoid transcription factor network, a key regulatory axis required for early cell fate decisions in the vertebrate embryo. This establishes polysialyltransferase genes as part of a developmental program associated with germ layer establishment. Finally, we show by shRNA knockdown and CRISPR-Cas9 genome editing that PST-dependent cell surface polysialylation is essential for endoderm specification. This is the first report to demonstrate a role for a glycosyltransferase in hPSC lineage specification. Stem Cells 2016;34:1742-1752.

  10. Pediatric primary central nervous system germ cell tumors of different prognosis groups show characteristic miRNome traits and chromosome copy number variations

    PubMed Central

    2010-01-01

    Background Intracranial pediatric germ cell tumors (GCTs) are rare and heterogeneous neoplasms and vary in histological differentiation, prognosis and clinical behavior. Germinoma and mature teratoma are GCTs that have a good prognosis, while other types of GCTs, termed nongerminomatous malignant germ cell tumors (NGMGCTs), are tumors with an intermediate or poor prognosis. The second group of tumors requires more extensive drug and irradiation treatment regimens. The mechanisms underlying the differences in incidence and prognosis of the various GCT subgroups are unclear. Results We identified a distinct mRNA profile correlating with GCT histological differentiation and prognosis, and also present in this study the first miRNA profile of pediatric primary intracranial GCTs. Most of the differentially expressed miRNAs were downregulated in germinomas, but miR-142-5p and miR-146a were upregulated. Genes responsible for self-renewal (such as POU5F1 (OCT4), NANOG and KLF4) and the immune response were abundant in germinomas, while genes associated with neuron differentiation, Wnt/β-catenin pathway, invasiveness and epithelial-mesenchymal transition (including SNAI2 (SLUG) and TWIST2) were abundant in NGMGCTs. Clear transcriptome segregation based on patient survival was observed, with malignant NGMGCTs being closest to embryonic stem cells. Chromosome copy number variations (CNVs) at cytobands 4q13.3-4q28.3 and 9p11.2-9q13 correlated with GCT malignancy and clinical risk. Six genes (BANK1, CXCL9, CXCL11, DDIT4L, ELOVL6 and HERC5) within 4q13.3-4q28.3 were more abundant in germinomas. Conclusions Our results integrate molecular profiles with clinical observations and provide insights into the underlying mechanisms causing GCT malignancy. The genes, pathways and microRNAs identified have the potential to be novel therapeutic targets. PMID:20178649

  11. The Primary Electroviscous Effect: Thin Double Layers (akappa>1) and a Stern Layer.

    PubMed

    Sherwood; Rubio-Hernández; Ruiz-Reina

    2000-08-01

    The primary electroviscous effect due to the charge clouds surrounding spherical charged particles suspended in an electrolyte was studied by Hinch and Sherwood (J. Fluid Mech. 132, 337 (1983)) in the limit of double layers thin compared to the particle radius a. Here we introduce the effect of a dynamic Stern layer into that analysis, in order to explain the numerical results of Rubio-Hernández et al. (J. Colloid Interface Sci. 206, 334 (1998)) in terms of the ratio of the tangential ionic fluxes within the charge cloud to those within the Stern layer. The predictions of the asymptotic analysis are compared with those of numerical computations. The thickness of the charge cloud is characterized by the Debye length kappa(-1). If akappa>10 the predictions of the asymptotic analysis exhibit the same qualitative behavior as the numerical results, but akappa>1000 is required to achieve quantitative agreement to within 2.5%. Copyright 2000 Academic Press.

  12. Angiosarcoma associated with germ cell tumors

    SciTech Connect

    Ulbright, T.M.; Clark, S.A.; Einhorn, L.H.

    1985-03-01

    In two patients with malignant germ cell tumors angiosarcoma developed through two apparently different mechanisms. In one case the angiosarcoma probably developed as a complication of therapeutic radiation, since radiation changes were demonstrated in tissue adjacent to the neoplasm and since the angiosarcoma was not associated with elements of germ cell tumor. The absence of associated germ cell elements does not support the development of the angiosarcoma from a teratoma. In the second case, however, it is likely that the angiosarcoma developed as a result of malignant change within teratomatous foci, since angiosarcomatous elements were intermingled with teratomatous elements and the patient's primary germ cell tumor contained malignant and atypical teratomatous elements as well as prominent vascular proliferation. Malignant change within teratomatous components of germ cell tumors is a phenomenon of increasing importance in this era of effective chemotherapy for germ cell tumors. The development of angiosarcoma as a potential complication of testicular carcinoma has not been reported previously.

  13. Pluripotent stem cells from germ cells.

    PubMed

    Kerr, Candace L; Shamblott, Michael J; Gearhart, John D

    2006-01-01

    To date, stem cells have been derived from three sources of germ cells. These include embryonic germ cells (EGCs), embryonal carcinoma cells (ECCs), and multipotent germ line stem cells (GSCs). EGCs are derived from primordial germ cells that arise in the late embryonic and early fetal period of development. ECCs are derived from adult testicular tumors whereas GSCs have been derived by culturing spermatogonial stem cells from mouse neonates and adults. For each of these lines, their pluripotency has been demonstrated by their ability to differentiate into cell types derived from the three germ layers in vitro and in vivo and in chimeric animals, including germ line transmission. These germ line-derived stem cells have been generated from many species including human, mice, porcine, and chicken albeit with only slight modifications. This chapter describes general considerations regarding critical aspects of their derivation compared with their counterpart, embryonic stem cells (ESCs). Detailed protocols for EGC derivation and maintenance from human and mouse primordial germ cells (PGCs) will be presented.

  14. Dissecting Germ Cell Metabolism through Network Modeling

    PubMed Central

    Whitmore, Leanne S.; Ye, Ping

    2015-01-01

    Metabolic pathways are increasingly postulated to be vital in programming cell fate, including stemness, differentiation, proliferation, and apoptosis. The commitment to meiosis is a critical fate decision for mammalian germ cells, and requires a metabolic derivative of vitamin A, retinoic acid (RA). Recent evidence showed that a pulse of RA is generated in the testis of male mice thereby triggering meiotic commitment. However, enzymes and reactions that regulate this RA pulse have yet to be identified. We developed a mouse germ cell-specific metabolic network with a curated vitamin A pathway. Using this network, we implemented flux balance analysis throughout the initial wave of spermatogenesis to elucidate important reactions and enzymes for the generation and degradation of RA. Our results indicate that primary RA sources in the germ cell include RA import from the extracellular region, release of RA from binding proteins, and metabolism of retinal to RA. Further, in silico knockouts of genes and reactions in the vitamin A pathway predict that deletion of Lipe, hormone-sensitive lipase, disrupts the RA pulse thereby causing spermatogenic defects. Examination of other metabolic pathways reveals that the citric acid cycle is the most active pathway. In addition, we discover that fatty acid synthesis/oxidation are the primary energy sources in the germ cell. In summary, this study predicts enzymes, reactions, and pathways important for germ cell commitment to meiosis. These findings enhance our understanding of the metabolic control of germ cell differentiation and will help guide future experiments to improve reproductive health. PMID:26367011

  15. Testicular germ cell tumors.

    PubMed

    Looijenga, Leendert H J

    2014-02-01

    Human germ cell tumors are of interest because of their epidemiology, clinical behavior and pathobiology. Histologically, they are subdivided into various elements, with similarities to embryogenesis. Recent insights resulted in a division of five types of human germ cell tumors. In the context of male germ cells, three are relevant; Type I: teratomas and yolk sac tumors of neonates and infants; Type II: seminomas and nonseminomas of (predominantly) adolescents and adults; and Type III: spermatocytic seminomas of the elderly. Recent studies led to significant increases in understanding of the parameters involved in the earliest pathogenetic steps of human germ cells tumors, in particularly the seminomas and nonseminomas (Type II). In case of a disturbed gonadal physiology, either due to the germ cell itself, or the micro-environment, embryonic germ cells during a specific window of sensitization can be blocked in their maturation, resulting in carcinoma in situ or gonadoblastoma, the precursors of seminomas and nonseminomas. The level of testicularization of the gonad determines the histological composition of the precursor. These insights will allow better definition of individuals at risk to develop a germ cell malignancy, with putative preventive measurements, and allow better selection of scientific approaches to elucidate the pathogenesis. PMID:24683949

  16. [Retroperitoneal germ cell tumor].

    PubMed

    Borrell Palanca, A; García Garzón, J; Villamón Fort, R; Domenech Pérez, C; Martínez Lorente, A; Gunthner, S; García Sisamón, F

    1999-03-01

    We report a case of retroperitoneal extragonadal germ-cell tumor in an 17 years old patient who presented with aedema and pain in left inferior extremity asociated with hemopthysis caused by pulmonar metastasis, who was treated with chemotherapy and resection of residual mass and pulmonary nodes. Dyagnosis was stableshed by fine neadle aspiration biopsy of the wass. We comment on the difficult of stableshing differential dyagnosis between retroperitoneal extragonadal germ-cell tumor and metastasis of a testicular tumor. Dyagnosis is stableshed by the finding of a histologically malignant germ-cell tumor with normal testis. We considered physical examination and ecographyc exploration enough for a correct dyagnosis.

  17. Genomic Landscape of Developing Male Germ Cells

    PubMed Central

    Lee, Tin-Lap; Pang, Alan Lap-Yin; Rennert, Owen M.; Chan, Wai-Yee

    2010-01-01

    Spermatogenesis is a highly orchestrated developmental process by which spermatogonia develop into mature spermatozoa. This process involves many testis- or male germ cell-specific gene products whose expressions are strictly regulated. In the past decade the advent of high-throughput gene expression analytical techniques has made functional genomic studies of this process, particularly in model animals such as mice and rats, feasible and practical. These studies have just begun to reveal the complexity of the genomic landscape of the developing male germ cells. Over 50% of the mouse and rat genome are expressed during testicular development. Among transcripts present in germ cells, 40% – 60% are uncharacterized. A number of genes, and consequently their associated biological pathways, are differentially expressed at different stages of spermatogenesis. Developing male germ cells present a rich repertoire of genetic processes. Tissue-specific as well as spermatogenesis stage-specific alternative splicing of genes exemplifies the complexity of genome expression. In addition to this layer of control, discoveries of abundant presence of antisense transcripts, expressed psuedogenes, non-coding RNAs (ncRNA) including long ncRNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), and retrogenes all point to the presence of multiple layers of expression and functional regulation in male germ cells. It is anticipated that application of systems biology approaches will further our understanding of the regulatory mechanism of spermatogenesis.† PMID:19306351

  18. What Are Germs?

    MedlinePlus

    ... four major types of germs are: bacteria, viruses, fungi, and protozoa. They can invade plants, animals, and ... countertop, be sure to wash your hands regularly! Fungi (say: FUN-guy) are multi-celled (made of ...

  19. Pyramidal Neuron Number in Layer 3 of Primary Auditory Cortex of Subjects with Schizophrenia

    PubMed Central

    Dorph-Petersen, Karl-Anton; Delevich, Kristen M.; Marcsisin, Michael J.; Zhang, Wei; Sampson, Allan R.; Gundersen, Hans Jørgen G.; Lewis, David A.; Sweet, Robert A.

    2009-01-01

    Individuals with schizophrenia demonstrate impairments of sensory processing within primary auditory cortex. We have previously identified lower densities of dendritic spines and axon boutons, and smaller mean pyramidal neuron somal volume, in layer 3 of the primary auditory cortex in subjects with schizophrenia, all of which might reflect fewer layer 3 pyramidal neurons in schizophrenia. To examine this hypothesis, we developed a robust stereological method based upon unbiased principles for estimation of total volume and pyramidal neuron numbers for each layer of a cortical area. Our method generates both a systematic, uniformly random set of mapping sections as well as a set of randomly rotated sections cut orthogonal to the pial surface, within the region of interest. We applied our approach in twelve subjects with schizophrenia, each matched to a normal comparison subject. Primary auditory cortex volume was assessed using Cavalieri’s method. The relative and absolute volume of each cortical layer and, within layer 3, the number and density of pyramidal neurons was estimated using our novel approach. Subject groups did not differ in regional volume, layer volumes, or pyramidal neuron number, although pyramidal neuron density was significantly greater in subjects with schizophrenia. These findings suggest that previously observed lower densities of dendritic spines and axon boutons reflect fewer numbers per neuron, and contribute to greater neuronal density via a reduced neuropil. Our approach represents a powerful new method for stereologic estimation of features of interest within individual layers of cerebral cortex, with applications beyond the current study. PMID:19524554

  20. A model study of seasonal mixed-layer primary production in the Arabian Sea

    NASA Astrophysics Data System (ADS)

    Brock, John; Sathyendranath, Shubha; Platt, Trevor

    1994-06-01

    We combined a surface irradiance model with a non-spectral photosynthesisirradiance model to estimate the daily, average rate of mixed-layer primary production in the Arabian Sea for the 15th day of months at the end of the northeast monsoon, the southwest monsoon, and the fall and spring inter-monsoons. Our model experiment uses climatologies of cloud cover, mixed-layer thickness, and satellite ocean-color observations of phytoplankton biomass. Modelled surface radiation is at an annual maximum in May beneath nearly cloud-free skies just prior to the summer solstice. The model estimate of surface radiation diminishes through the southwest monsoon over most of the northern Arabian Sea to an annual minimum in August due to intense cloudiness. In agreement with previous ship-based measurements, the photosynthesis-irradiance model predicts that the mixed-layer primary production in the Arabian Sea is extremely seasonal, and peaks annually during the southwest monsoon to the north-west of the atmospheric Findlater Jet and along the coast of Somalia. Northern Arabian Sea maxima predicted for both the summer and winter monsoons are separated by periods of low mixed-layer primary production, the fall and spring inter-monsoons. The annual cycles of modelled mixed-layer primary production differ by region in the Arabian Sea due to varying monsoon influence and circulation dynamics.

  1. RNA Granules in Germ Cells

    PubMed Central

    Voronina, Ekaterina; Seydoux, Geraldine; Sassone-Corsi, Paolo; Nagamori, Ippei

    2011-01-01

    Germ granules” are cytoplasmic, nonmembrane-bound organelles unique to germline. Germ granules share components with the P bodies and stress granules of somatic cells, but also contain proteins and RNAs uniquely required for germ cell development. In this review, we focus on recent advances in our understanding of germ granule assembly, dynamics, and function. One hypothesis is that germ granules operate as hubs for the posttranscriptional control of gene expression, a function at the core of the germ cell differentiation program. PMID:21768607

  2. Zebrafish Germ Cell Tumors.

    PubMed

    Sanchez, Angelica; Amatruda, James F

    2016-01-01

    Germ cell tumors (GCTs) are malignant cancers that arise from embryonic precursors known as Primordial Germ Cells. GCTs occur in neonates, children, adolescents and young adults and can occur in the testis, the ovary or extragonadal sites. Because GCTs arise from pluripotent cells, the tumors can exhibit a wide range of different histologies. Current cisplatin-based combination therapies cures most patients, however at the cost of significant toxicity to normal tissues. While GWAS studies and genomic analysis of human GCTs have uncovered somatic mutations and loci that might confer tumor susceptibility, little is still known about the exact mechanisms that drive tumor development, and animal models that faithfully recapitulate all the different GCT subtypes are lacking. Here, we summarize current understanding of germline development in humans and zebrafish, describe the biology of human germ cell tumors, and discuss progress and prospects for zebrafish GCT models that may contribute to better understanding of human GCTs. PMID:27165367

  3. Environmentally induced transgenerational epigenetic reprogramming of primordial germ cells and the subsequent germ line.

    PubMed

    Skinner, Michael K; Guerrero-Bosagna, Carlos; Haque, M; Nilsson, Eric; Bhandari, Ramji; McCarrey, John R

    2013-01-01

    A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided.

  4. Environmentally Induced Transgenerational Epigenetic Reprogramming of Primordial Germ Cells and the Subsequent Germ Line

    PubMed Central

    Skinner, Michael K.; Haque, Carlos Guerrero-Bosagna M.; Nilsson, Eric; Bhandari, Ramji; McCarrey, John R.

    2013-01-01

    A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided. PMID:23869203

  5. Extragonadal Germ Cell Cancer (EGC)

    MedlinePlus

    ... Testicular Cancer Resource Center Extragonadal Germ Cell Cancer (EGC) 95% of all testicular tumors are germ cell ... seen in young adults. Patients with mediastinal nonseminomatous EGC are typically classed as poor risk patients because ...

  6. The boundary layers as the primary transport regions of the earth's magnetotail

    NASA Technical Reports Server (NTRS)

    Eastman, T. E.; Frank, L. A.; Huang, C. Y.

    1985-01-01

    A comprehensive survey of ISEE and IMP LEPEDEA plasma measurements in the earth's magnetotail reveals that the magnetospheric boundary layer and the plasma sheet boundary layer are the primary transport regions there. These plasma measurements also reveal various components of the plasma sheet, including the central plasma sheet and plasma sheet boundary layer. A significant new result reported here is that of cold- and hot-plasma components that are spatially co-present within the central plasma sheet. Such plasma components cannot be explained merely by temporal variations in spectra involving the entire plasma sheet. Contributions to a low temperature component of the plasma sheet enter directly from the boundary layer located along the magnetotail flanks. Field-aligned flows predominate within the plasma sheet boundary layer which is almost always present and is located near the high- and low-latitude border of the plasma sheet. The plasma sheet boundary layer comprises highly anisotropic ion distributions, including counter-streaming ion beams, that evolve into the hot, isotropic component of the plasma sheet. Tailward acceleration regions generate these ion beams with plasma input from the magnetospheric boundary layer. Antisunward-flowing ion beams, at E/q less than 1 kV and of ionospheric composition, are frequently observed in the plasma sheet boundary layer and in tail lobes. These ion beams are likely accelerated at low altitude over the polar cap and especially along auroral field lines.

  7. AiGERM: A logic programming front end for GERM

    NASA Technical Reports Server (NTRS)

    Hashim, Safaa H.

    1990-01-01

    AiGerm (Artificially Intelligent Graphical Entity Relation Modeler) is a relational data base query and programming language front end for MCC (Mission Control Center)/STP's (Space Test Program) Germ (Graphical Entity Relational Modeling) system. It is intended as an add-on component of the Germ system to be used for navigating very large networks of information. It can also function as an expert system shell for prototyping knowledge-based systems. AiGerm provides an interface between the programming language and Germ.

  8. Germs and Hygiene

    MedlinePlus

    ... diaper Avoiding touching your eyes, nose or mouth Hand washing is one of the most effective and most overlooked ways to stop disease. Soap and water work well to kill germs. Wash for at least 20 seconds and rub your hands briskly. Disposable hand wipes or gel sanitizers also ...

  9. The effects of temporal variability of mixed layer depth on primary productivity around Bermuda

    NASA Technical Reports Server (NTRS)

    Bissett, W. Paul; Meyers, Mark B.; Walsh, John J.; Mueller-Karger, Frank E.

    1994-01-01

    Temporal variations in primary production and surface chlorophyll concentrations, as measured by ship and satellite around Bermuda, were simulated with a numerical model. In the upper 450 m of the water column, population dynamics of a size-fractionated phytoplankton community were forced by daily changes of wind, light, grazing stress, and nutrient availability. The temporal variations of production and chlorophyll were driven by changes in nutrient introduction to the euphotic zone due to both high- and low-frequency changes of the mixed layer depth within 32 deg-34 deg N, 62 deg-64 deg W between 1979 and 1984. Results from the model derived from high-frequency (case 1) changes in the mixed layer depth showed variations in primary production and peak chlorophyll concentrations when compared with results from the model derived from low-frequency (case 2) mixed layer depth changes. Incorporation of size-fractionated plankton state variables in the model led to greater seasonal resolution of measured primary production and vertical chlorophyll profiles. The findings of this study highlight the possible inadequacy of estimating primary production in the sea from data of low-frequency temporal resolution and oversimplified biological simulations.

  10. Electron microscopy of the germ cells and the ovarian wall in Xiphinema (Nematoda).

    PubMed

    Van de Velde, M C; Coomans, A

    1988-01-01

    The ovary of Xiphinema theresiae is studied ultrastructurally. It consists of two cell types, the ovarian epithelial cells and the germ cells. The ovarian epithelial cells form a thin layer around the germ cells. Their nuclei are located in between the germ cells. At some sites, processes of the ovarian epithelial cells migrate inward and form a central cytoplasmic mass. The germ cells have a large lobated nucleus, with an eccentric nucleolus, and are considered to represent young previtellogenic oocytes. In contact with the central cytoplasmic mass, the germ cells develop two membrane derived features, the villi and the small coated bulges, which most probably play a role in transport.

  11. Epigenetic Regulation of Germ Cells— Remember or Forget?

    PubMed Central

    Feng, Lijuan; Chen, Xin

    2015-01-01

    Unlike somatic cells, germ cells retain the potential to reproduce an entire new organism upon fertilization. In order to accomplish the process of fertilization, germ cells undergo an extreme cellular differentiation process known as gametogenesis in order to produce morphologically and functionally distinct oocyte and sperm. In addition to changes in genetic content changes from diploid to haploid, epigenetic mechanisms that modify chromatin state without altering primary DNA sequences have profound influence on germ cell differentiation and moreover, the transgenerational effect. In this review, we will go over the most recent discoveries on epigenetic regulations in germline differentiation and transgenerational inheritance across different metazoan species. PMID:25930104

  12. Germ proof your school.

    PubMed

    Mattern, Cheryl S; Rotbart, Harley A

    2008-09-01

    Schools can be made safer from germs by: 1. Reinforcing students' personal health and hygiene practices such as hand washing, proper wound care, timely immunizations, nutritious diet, adequate sleep, reducing long-term stress, regular moderate exercise, and matching wardrobe to the weather; 2. Adherence to health department exclusion/inclusion policies for students who are infected, symptomatic, exposed to infection, or susceptible to infection; 3. Practicing sound environmental hygiene, with particular attention to surface disinfecting and food safety. PMID:18853908

  13. Non-seminomatous germ cell tumors of the testis. Analysis of CEA production in primary tumors and in retroperitoneal lymph node metastases after PVB chemotherapy.

    PubMed

    Suurmeijer, A J; Oosterhuis, J W; Marrink, J; Ockhuizen, T; Sleijfer, D T; Schraffordt Koops, H; Fleuren, G J

    1984-05-01

    In the present investigation we compared CEA immunoperoxidase staining in testicular tumors (before PVB chemotherapy) and retroperitoneal tumors (after PVB chemotherapy) with CEA levels in the cyst fluid of retroperitoneal mature teratoma and in the patients' serum. CEA had no value as a serum tumor marker since serum CEA elevations were not associated with tumor activity. Only one elevated CEA level after chemotherapy was associated with bleomycin pneumonitis. Despite normal serum levels, CEA was localized immunohistochemically in yolk sac tumor and mature teratoma in the primary tumors and in retroperitoneal mature teratoma following PVB chemotherapy. The presence of CEA in cells lining cystic mature teratoma was associated with high CEA levels in the cyst fluid.

  14. Experimental investigation of primary and corner shock boundary layer interactions at mild back pressure ratios

    NASA Astrophysics Data System (ADS)

    Funderburk, M.; Narayanaswamy, V.

    2016-08-01

    Unstart of rectangular inlets occurs as a result of interactions between shock-induced separation units along the floor/ceiling, corner, and sidewalls. While a significant body of literature exists regarding the individual flow interactions at the inlet floor/ceiling (called primary separation) and sidewalls, limited efforts have focused on the mean and dynamic features of the corner separation. Experiments are conducted to investigate primary and corner shock boundary layer interactions (SBLI) with the objectives of elucidating the flow interactions that occur in the corner, and characterizing the interaction between the corner and primary separation units at mild back pressure ratios. Surface streakline flow visualization and high-frequency wall static pressure measurements are performed along the centerline and corner regions of shock-induced flow separation generated by a 12° compression ramp in a Mach 2.5 flow. Sidewall fences that extend upstream of the leading edge of the flat plate generate corner separation of adequate size to determine the mean flow structures, characterize the unsteady motions, and investigate the mechanisms that drive the unsteadiness of primary and corner SBLI. Results show that the corner and primary SBLI units differ fundamentally in both their mean and unsteady features and their response to upstream and downstream flow perturbations. These observations suggest that the two behave as independent units at this relatively low shock-induced back pressure ratio.

  15. [Mediastinal germ cell tumors].

    PubMed

    Bremmer, F; Ströbel, P

    2016-09-01

    The mediastinum is among the most frequent anatomic region in which germ cell tumors (GCT) arise, second only to the gonads. Mediastinal GCT (mGCT) account for 16 % of all mediastinal neoplasms. Although the morphology and (according to all available data) the molecular genetics of mediastinal and gonadal GCT are identical, a number of unique aspects exist. There is a highly relevant bi-modal age distribution. In pre-pubertal children of both sexes, mGCT consist exclusively of teratomas and yolk sac tumors. The prognosis is generally favorable with modern treatment. In post-pubertal adults, virtually all patients with malignant mGCT are males; the prognosis is more guarded and depends (among other factors) on the histological GCT components and is similar to GCT in other organs. So-called somatic type malignancies (i. e. clonally related, non-germ cell neoplasias arising in a GCT) are much more frequent in mGCT than in other organs, and the association between mediastinal yolk sac tumors and hematological malignancies, such as myelodysplasias and leukemias, is unique to mediastinal tumors. The prognosis of GCT with somatic type malignancies is generally dismal. PMID:27491549

  16. Modular Representation of Luminance Polarity in the Superficial Layers of Primary Visual Cortex.

    PubMed

    Smith, Gordon B; Whitney, David E; Fitzpatrick, David

    2015-11-18

    The spatial arrangement of luminance increments (ON) and decrements (OFF) falling on the retina provides a wealth of information used by central visual pathways to construct coherent representations of visual scenes. But how the polarity of luminance change is represented in the activity of cortical circuits remains unclear. Using wide-field epifluorescence and two-photon imaging we demonstrate a robust modular representation of luminance polarity (ON or OFF) in the superficial layers of ferret primary visual cortex. Polarity-specific domains are found with both uniform changes in luminance and single light/dark edges, and include neurons selective for orientation and direction of motion. The integration of orientation and polarity preference is evident in the selectivity and discrimination capabilities of most layer 2/3 neurons. We conclude that polarity selectivity is an integral feature of layer 2/3 neurons, ensuring that the distinction between light and dark stimuli is available for further processing in downstream extrastriate areas. PMID:26590348

  17. Effect of the sodium hypochlorite and citric acid association on smear layer removal of primary molars.

    PubMed

    Götze, Gabriela da Rosa; Cunha, Cristiane Beatriz Costa Sales; Primo, Laura Salignac de Souza Guimarães; Maia, Lucianne Cople

    2005-01-01

    This study aimed to assess the capacity of a sodium hypochlorite and citric acid (CA) association (the latter at different concentrations) in removing coronal smear layer (SL) of primary teeth. For this purpose, the pulp chamber roof and floor of 28 primary molars were removed to obtain enamel and dentine disks. SL was produced on the internal walls of the disks using high-speed drills. The disks were irrigated with 1% sodium hypochlorite and citric acid at different concentrations (CA-4%, CA-6%, CA-8% and CA-10%), and with 0.9% sodium chloride. The samples were split and observed under SEM. Scores were attributed to the obtained photomicrographs, according to the amount of SL present. It was noted that all the tested concentrations of citric acid used after the sodium hypochlorite were capable of removing SL. The results were analyzed by the Kruskal-Wallis test, and there was no significant statistical difference among the scores of the groups tested. However, it was observed that CA-8% and CA-10% caused peritubular dentine destruction, and that CA-4% presented a larger number of samples with dense SL. Based on these results, 6.0% citric acid in association with 1% sodium hypochlorite is suggested as auxiliary chemical substances for primary teeth irrigation.

  18. Differentiating neoplasms of hair germ

    PubMed Central

    Headington, J. T.

    1970-01-01

    Differentiating neoplasms of hair germ are benign epithelial-mesenchymal tumours of skin in which hair follicle development may be partly or completely recapitulated. The epithelial component is equivalent to the hair germ. The mesenchymal component is equivalent to the dermal papilla. Epithelial-mesenchymal interaction results in the morphogenesis of hair follicles. In neoplasms showing stromal induction, there is centrifugal organizations: hair bulbs are found at the periphery of tumour lobules and hairs are projected centrally to lie within small keratinizing cysts. Neoplasms of hair germ without advanced morpho-differentiation are termed `trichoblastomas', and those neoplasms in which hair follicle development is advanced are called `trichogenic trichoblastomas'. Images PMID:5476873

  19. Germ cell tumor located in the midline of the anterior neck.

    PubMed

    Pirdopska, Tatyana; Terziev, Ivan; Hristova, Sv; Mladenovsky, W; Petkov, R

    2011-01-01

    Primary germ cell tumors involving midline of the anterior neck are extremely rare. Here we report a 68-year-old male who was operated due to a mass lesion in the anterior neck with infiltration of the isthmus of the thyroid gland. Histopathological examination revealed a germ cell tumor with extragonadal localization in the anterior neck infiltrating the isthmus of the thyroid gland.

  20. Quantifying subtropical North Pacific gyre mixed layer primary productivity from Seaglider observations of diel oxygen cycles

    NASA Astrophysics Data System (ADS)

    Nicholson, David P.; Wilson, Samuel T.; Doney, Scott C.; Karl, David M.

    2015-05-01

    Using autonomous underwater gliders, we quantified diurnal periodicity in dissolved oxygen, chlorophyll, and temperature in the subtropical North Pacific near the Hawaii Ocean Time-series (HOT) Station ALOHA during summer 2012. Oxygen optodes provided sufficient stability and precision to quantify diel cycles of average amplitude of 0.6 µmol kg-1. A theoretical diel curve was fit to daily observations to infer an average mixed layer gross primary productivity (GPP) of 1.8 mmol O2 m-3 d-1. Cumulative net community production (NCP) over 110 days was 500 mmol O2 m-2 for the mixed layer, which averaged 57 m in depth. Both GPP and NCP estimates indicated a significant period of below-average productivity at Station ALOHA in 2012, an observation confirmed by 14C productivity incubations and O2/Ar ratios. Given our success in an oligotrophic gyre where biological signals are small, our diel GPP approach holds promise for remote characterization of productivity across the spectrum of marine environments.

  1. Thalamus provides layer 4 of primary visual cortex with orientation- and direction-tuned inputs

    PubMed Central

    Sun, Wenzhi; Tan, Zhongchao; Mensh, Brett D.; Ji, Na

    2015-01-01

    Understanding the functions of a brain region requires knowing the neural representations of its myriad inputs, local neurons, and outputs. Primary visual cortex (V1) has long been thought to compute visual orientation from untuned thalamic inputs, but very few thalamic inputs have been measured in any mammal. We determined the response properties of ~28,000 thalamic boutons and ~4,000 cortical neurons in layers 1–5 of awake mouse V1. With adaptive optics allowing accurate measurement of bouton activity deep in cortex, we found that around half of the boutons in the main thalamorecipient L4 carry orientation-tuned information, and their orientation/direction biases are also dominant in the L4 neuron population, suggesting that these neurons may inherit their selectivity from tuned thalamic inputs. Cortical neurons in all layers exhibited sharper tuning than thalamic boutons and a greater diversity of preferred orientations. Our results provide data-rich constraints for refining mechanistic models of cortical computation. PMID:26691829

  2. Palifosfamide in Treating Patients With Recurrent Germ Cell Tumors

    ClinicalTrials.gov

    2015-06-11

    Adult Central Nervous System Germ Cell Tumor; Adult Teratoma; Malignant Extragonadal Germ Cell Tumor; Malignant Extragonadal Non-Seminomatous Germ Cell Tumor; Extragonadal Seminoma; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Stage IV Extragonadal Non-Seminomatous Germ Cell Tumor; Stage IV Extragonadal Seminoma; Stage IV Ovarian Germ Cell Tumor

  3. Security risk assessment of the primary layer of wavelength division multiplexing passive optical network

    NASA Astrophysics Data System (ADS)

    Koudelka, Petr; Siska, Petr; Latal, Jan; Poboril, Radek; Hajek, Lukas; Kepak, Stanislav; Vasinek, Vladimir

    2015-01-01

    Next-generation passive optical access networks come to the fore nowadays. These optical next-generation networks are the response to the increasing qualitative requirements from end users. Technologies using Time Division Multiplexing include NG-PON (XG-PON 1 and XG-PON 2) and 10GEPON. Their advantage is the applicability to older topologies, which are operated by the original technology of passive optical access networks. Wavelength Division Multiplexing Passive Optical Network (WDM-PON) is an alternative also belonging to next-generation networks. Time Division Multiplexing is in this case replaced by Wavelength Division Multiplexing. Certain variants of WDM-PON use a combination of broadband light source, optical circulator, optical phased array and tunable FP laser. Construction of the terminal units (ONU) is advantageous because it can always tune in to the appropriate wavelength in the given optical DWDM channel (100 GHz). The disadvantage is the increased security risk on the primary layer due to channel crosstalk in an optical phased array (AWG). The aim of this paper is to assess the degree of security risk in real conditions. The article includes both simulation and real measurements in C + L bands with 100 GHz DWDM spacing.

  4. Cortical and thalamic contributions to response dynamics across layers of the primary somatosensory cortex during tactile discrimination

    PubMed Central

    Pais-Vieira, Miguel; Kunicki, Carolina; Tseng, Po-He; Martin, Joel; Lebedev, Mikhail

    2015-01-01

    Tactile information processing in the rodent primary somatosensory cortex (S1) is layer specific and involves modulations from both thalamocortical and cortico-cortical loops. However, the extent to which these loops influence the dynamics of the primary somatosensory cortex while animals execute tactile discrimination remains largely unknown. Here, we describe neural dynamics of S1 layers across the multiple epochs defining a tactile discrimination task. We observed that neuronal ensembles within different layers of the S1 cortex exhibited significantly distinct neurophysiological properties, which constantly changed across the behavioral states that defined a tactile discrimination. Neural dynamics present in supragranular and granular layers generally matched the patterns observed in the ventral posterior medial nucleus of the thalamus (VPM), whereas the neural dynamics recorded from infragranular layers generally matched the patterns from the posterior nucleus of the thalamus (POM). Selective inactivation of contralateral S1 specifically switched infragranular neural dynamics from POM-like to those resembling VPM neurons. Meanwhile, ipsilateral M1 inactivation profoundly modulated the firing suppression observed in infragranular layers. This latter effect was counterbalanced by contralateral S1 block. Tactile stimulus encoding was layer specific and selectively affected by M1 or contralateral S1 inactivation. Lastly, causal information transfer occurred between all neurons in all S1 layers but was maximal from infragranular to the granular layer. These results suggest that tactile information processing in the S1 of awake behaving rodents is layer specific and state dependent and that its dynamics depend on the asynchronous convergence of modulations originating from ipsilateral M1 and contralateral S1. PMID:26180115

  5. Cortical and thalamic contributions to response dynamics across layers of the primary somatosensory cortex during tactile discrimination.

    PubMed

    Pais-Vieira, Miguel; Kunicki, Carolina; Tseng, Po-He; Martin, Joel; Lebedev, Mikhail; Nicolelis, Miguel A L

    2015-09-01

    Tactile information processing in the rodent primary somatosensory cortex (S1) is layer specific and involves modulations from both thalamocortical and cortico-cortical loops. However, the extent to which these loops influence the dynamics of the primary somatosensory cortex while animals execute tactile discrimination remains largely unknown. Here, we describe neural dynamics of S1 layers across the multiple epochs defining a tactile discrimination task. We observed that neuronal ensembles within different layers of the S1 cortex exhibited significantly distinct neurophysiological properties, which constantly changed across the behavioral states that defined a tactile discrimination. Neural dynamics present in supragranular and granular layers generally matched the patterns observed in the ventral posterior medial nucleus of the thalamus (VPM), whereas the neural dynamics recorded from infragranular layers generally matched the patterns from the posterior nucleus of the thalamus (POM). Selective inactivation of contralateral S1 specifically switched infragranular neural dynamics from POM-like to those resembling VPM neurons. Meanwhile, ipsilateral M1 inactivation profoundly modulated the firing suppression observed in infragranular layers. This latter effect was counterbalanced by contralateral S1 block. Tactile stimulus encoding was layer specific and selectively affected by M1 or contralateral S1 inactivation. Lastly, causal information transfer occurred between all neurons in all S1 layers but was maximal from infragranular to the granular layer. These results suggest that tactile information processing in the S1 of awake behaving rodents is layer specific and state dependent and that its dynamics depend on the asynchronous convergence of modulations originating from ipsilateral M1 and contralateral S1.

  6. New evidence for the origin of intracranial germ cell tumours from primordial germ cells: expression of pluripotency and cell differentiation markers.

    PubMed

    Hoei-Hansen, C E; Sehested, A; Juhler, M; Lau, Y-F C; Skakkebaek, N E; Laursen, H; Rajpert-de Meyts, E

    2006-05-01

    Primary intracranial germ cell tumours are rare neoplasms that occur in children and adolescents. This study examined both the biology and the origin of these tumours, as it has been hypothesized that they originate from a totipotent primordial germ cell. We applied recent knowledge from gonadal germ cell tumours and analysed expression of a wide panel of stem cell-related proteins (C-KIT, OCT-3/4 (POU5F1), AP-2gamma (TFAP2C), and NANOG) and developmentally regulated germ cell-specific proteins (including MAGE-A4, NY-ESO-1, and TSPY). Expression at the protein level was analysed in 21 children and young adults with intracranial germinomas and non-germinomas, contributing to a careful description of these unusual tumours and adding to the understanding of pathogenesis. Stem cell related proteins were highly expressed in intracranial germ cell tumours, and many similarities were detected with their gonadal equivalents, including a close similarity with primordial germ cells. A notable difference was the sex-specific expression of TSPY, a gene previously implicated in the origin of gonadoblastoma. TSPY was only detected in germ cell tumours in the central nervous system (CNS) from males, suggesting that it is not required for the initiation of malignant germ cell transformation. The expression of genes associated with embryonic stem cell pluripotency in CNS germ cell tumours strongly suggests that these tumours are derived from cells that retain, at least partially, an embryonic stem cell-like phenotype, which is a hallmark of primordial germ cells. PMID:16456896

  7. General Information about Extragonadal Germ Cell Tumors

    MedlinePlus

    ... Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Extragonadal Germ Cell Tumors Go to Health ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  8. General Information about Ovarian Germ Cell Tumors

    MedlinePlus

    ... Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Ovarian Germ Cell Tumors Go to Health ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  9. Identification of Potential Germ-Cell Mutagens

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Various rodent-based germ-cell mutation assays have been developed, and ~50 germ...

  10. HISTORY OF GERM CELL MUTAGENESIS

    EPA Science Inventory

    Much of the early work on germ cell mutation analysis was conducted with nonmammalian species, but this historical overview will begin with the rodent studies that provided quantitative data on induced mutations. The initial studies of mutation induction utilized the newly develo...

  11. Gove's Curriculum and the GERM

    ERIC Educational Resources Information Center

    Wrigley, Terry

    2015-01-01

    This article examines the complex relationship between England's new National Curriculum and the neoliberal reform of education known as GERM. It explores contradictions between economic functionality and Gove's nostalgic traditionalism. It critiques the new curriculum as narrow, age-inappropriate, obsessed with abstract rules, and poorly focused…

  12. Microleakage and Micrographic Evaluation of Composite Restorations with Various Bases over ZOE Layer in Pulpotomized Primary Molars

    PubMed Central

    Bargrizan, M.; Mirkarimi, M.; Rezamand, M.; Eskandarion, S.

    2011-01-01

    Objective Zinc oxide eugenol (ZOE) under composite restorations should be covered with a suitable material in order to prevent the harmful effect of ZOE on the composite. The aim of this in vitro study was to evaluate microleakage of composite restorations in pulpotomized primary molars with different bases for covering the ZOE layer and to assess the distance between different layers. Materials and Methods Proximo-occlusal cavities were prepared in 78 extracted second primary molars. Carious lesions were removed and pulpotomy was carried out. Zinc oxide eugenol paste was placed in 2-mm thickness. The teeth were randomly divided in 6 groups and restored as follows: 1. Light-cured composite; 2. Resin-modified glass-ionomer and composite resin; 3. Glass-ionomer and composite resin; 4. Light-cured calcium hydroxide and composite resin; 5. Calcium hydroxide and composite resin; 6. Amalgam and composite resin. The restored specimens were thermocycled for 500 cycles (5°C/55°C) and microleakage was assessed by dye penetration technique. Three specimens from each group were processed for scanning electron microscope evaluation to determine the distance between the layers. The results were analyzed by Kruskal-Wallis and Dunn tests. Results Microleakage assessment revealed significant differences between the groups (P=0.04), with the amalgam group exhibiting the lowest microleakage values. In SEM micrographs no significant differences were observed in the distance between ZOE base layers (P=0.94) and base-composite layers (P=0.47); however, the amalgam group had the lowest distances. Conclusion The use of amalgam over zinc oxide eugenol layer in pulpotomized primary molars decreases microleakage. PMID:22509457

  13. The Geochemical Earth Reference Model (GERM)

    SciTech Connect

    Staudigel, H.; Albarede, F.; Shaw, H.; McDonough, B.; White, W.

    1996-12-01

    The Geochemical Earth Reference Model (GERM) initiative is a grass- roots effort with the goal of establishing a community consensus on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. Long term goal of GERM is a chemical reservoir characterization analogous to the geophysical effort of the Preliminary Reference Earth Model (PREM). Chemical fluxes between reservoirs are included into GERM to illuminate the long-term chemical evolution of the Earth and to characterize the Earth as a dynamic chemical system. In turn, these fluxes control geological processes and influence hydrosphere-atmosphere-climate dynamics. While these long-term goals are clearly the focus of GERM, the process of establishing GERM itself is just as important as its ultimate goal. The GERM initiative is developed in an open community discussion on the World Wide Web (GERM home page is at http://www-ep.es.llnl. gov/germ/germ-home.html) that is mediated by a series of editors with responsibilities for distinct reservoirs and fluxes. Beginning with the original workshop in Lyons (March 1996) GERM is continued to be developed on the Internet, punctuated by workshops and special sessions at professional meetings. It is planned to complete the first model by mid-1997, followed by a call for papers for a February 1998 GERM conference in La Jolla, California.

  14. Reprogramming of germ cells into pluripotency

    PubMed Central

    Sekita, Yoichi; Nakamura, Toshinobu; Kimura, Tohru

    2016-01-01

    Primordial germ cells (PGCs) are precursors of all gametes, and represent the founder cells of the germline. Although developmental potency is restricted to germ-lineage cells, PGCs can be reprogrammed into a pluripotent state. Specifically, PGCs give rise to germ cell tumors, such as testicular teratomas, in vivo, and to pluripotent stem cells known as embryonic germ cells in vitro. In this review, we highlight the current knowledge on signaling pathways, transcriptional controls, and post-transcriptional controls that govern germ cell differentiation and de-differentiation. These regulatory processes are common in the reprogramming of germ cells and somatic cells, and play a role in the pathogenesis of human germ cell tumors.

  15. Primordial Germ Cell Specification and Migration

    PubMed Central

    Marlow, Florence

    2015-01-01

    Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration. PMID:26918157

  16. Reprogramming of germ cells into pluripotency.

    PubMed

    Sekita, Yoichi; Nakamura, Toshinobu; Kimura, Tohru

    2016-08-26

    Primordial germ cells (PGCs) are precursors of all gametes, and represent the founder cells of the germline. Although developmental potency is restricted to germ-lineage cells, PGCs can be reprogrammed into a pluripotent state. Specifically, PGCs give rise to germ cell tumors, such as testicular teratomas, in vivo, and to pluripotent stem cells known as embryonic germ cells in vitro. In this review, we highlight the current knowledge on signaling pathways, transcriptional controls, and post-transcriptional controls that govern germ cell differentiation and de-differentiation. These regulatory processes are common in the reprogramming of germ cells and somatic cells, and play a role in the pathogenesis of human germ cell tumors. PMID:27621759

  17. Reprogramming of germ cells into pluripotency

    PubMed Central

    Sekita, Yoichi; Nakamura, Toshinobu; Kimura, Tohru

    2016-01-01

    Primordial germ cells (PGCs) are precursors of all gametes, and represent the founder cells of the germline. Although developmental potency is restricted to germ-lineage cells, PGCs can be reprogrammed into a pluripotent state. Specifically, PGCs give rise to germ cell tumors, such as testicular teratomas, in vivo, and to pluripotent stem cells known as embryonic germ cells in vitro. In this review, we highlight the current knowledge on signaling pathways, transcriptional controls, and post-transcriptional controls that govern germ cell differentiation and de-differentiation. These regulatory processes are common in the reprogramming of germ cells and somatic cells, and play a role in the pathogenesis of human germ cell tumors. PMID:27621759

  18. Primordial Germ Cells: Current Knowledge and Perspectives

    PubMed Central

    Nikolic, Aleksandar; Volarevic, Vladislav; Armstrong, Lyle; Lako, Majlinda; Stojkovic, Miodrag

    2016-01-01

    Infertility is a condition that occurs very frequently and understanding what defines normal fertility is crucial to helping patients. Causes of infertility are numerous and the treatment often does not lead to desired pregnancy especially when there is a lack of functional gametes. In humans, the primordial germ cell (PGC) is the primary undifferentiated stem cell type that will differentiate towards gametes: spermatozoa or oocytes. With the development of stem cell biology and differentiation protocols, PGC can be obtained from pluripotent stem cells providing a new therapeutic possibility to treat infertile couples. Recent studies demonstrated that viable mouse pups could be obtained from in vitro differentiated stem cells suggesting that translation of these results to human is closer. Therefore, the aim of this review is to summarize current knowledge about PGC indicating the perspective of their use in both research and medical application for the treatment of infertility. PMID:26635880

  19. A twist of fate: How a meiotic protein is providing new perspectives on germ cell development.

    PubMed

    Mainpal, Rana; Yanowitz, Judith L

    2016-01-01

    The molecular pathways that govern how germ line fate is acquired is an area of intense investigation that has major implications for the development of assisted reproductive technologies, infertility interventions, and treatment of germ cell cancers. Transcriptional repression has emerged as a primary mechanism to ensure suppression of somatic growth programs in primordial germ cells. In this commentary, we address how xnd-1 illuminates our understanding of transcriptional repression and how it is coordinated with the germ cell differentiation program. We recently identified xnd-1 as a novel, early determinant of germ cell fates in Caenorhabditis elegans. Our study revealed that XND-1 is maternally deposited into early embryos where it is selectively enriched in the germ lineage and then exclusively found on chromatin in the germ lineage throughout development and into adulthood when it dissociates from chromosomes in late pachytene. This localization is consistent with a range of interesting germ cell defects that suggest xnd-1 is a pivotal determinant of germ cell characteristics. Loss of xnd-1 results in a unique "one PGC (primordial germ cell)" phenotype due to G2 cell cycle arrest of the germline precursor blastomere, P4, which predisposes the animal and its progeny for reduced fecundity. The sterility in xnd-1 mutants is correlated with an increase in the transcriptional activation-associated histone modification, dimethylation of histone H3 lysine 4 (H3K4me2), and aberrant expression of somatic transgenes but overlapping roles with nos-2 and nos-1 suggest that transcriptional repression is achieved by multiple redundant mechanisms. PMID:27383565

  20. Polyoxin D inhibits colloidal gold-wheat germ agglutinin labelling of chitin in dimorphic forms of Candida albicans.

    PubMed

    Hilenski, L L; Naider, F; Becker, J M

    1986-06-01

    Yeasts and mycelia of the pathogen Candida albicans grown in the presence of polyoxin D, a competitive inhibitor of chitin synthase, formed chains of swollen bulbous cells as observed by fluorescence microscopy. Wheat germ agglutinin (WGA) complexed to colloidal gold (Au) was used as a specific label at the ultrastructural level to visualize chitin in walls of control and polyoxin-treated cells. In control cells, Au-WGA labelling was preferentially localized in the innermost wall layers and was predominant at bud scars and septa. After 4.5 h in 4 mM-polyoxin D, budding in yeasts and lateral wall growth in mycelia continued, but primary septa failed to form and no Au-WGA labelling was detected in the walls. These results demonstrated that the morphological alterations caused by polyoxin D were due to the absence of chitin, a wall component important for formation of primary septa and for maintenance of structural integrity during morphogenesis.

  1. Thermal stability of the surface layer and its relation to the dispersion of primary pollutants in St. Louis

    NASA Technical Reports Server (NTRS)

    Remsberg, E. E.; Woodbury, G. E.

    1982-01-01

    The present investigation is concerned with the applicability of the vertical temperature gradient, DT, as a dispersion parameter for urban area sources. Data on DT were tabulated from temperature measurements at 5 m and 30 m obtained on 30 m towers at 12 stations. DT was obtained by subtracting the value at 5 m from that at 30 m. Positive DT values represent an inversion. Accuracy of the DT data is 0.1 K. Hourly measurements of DT along with concentrations of the primary pollutants, CO, NO, and total hydrocarbons (THC), are available from the 1976 RAPS data base for St. Louis. Linear correlations between a given pollutant species concentration and DT are developed from that data set. It could be confirmed that a strong positive correlation exists at night between the thermal stability of the lowest part of the boundary layer and the urban concentration of the primary pollutants CO, NO, and hydrocarbons.

  2. Stability of the surface layer and its relation to the dispersion of primary pollutants in St. Louis

    NASA Technical Reports Server (NTRS)

    Remsberg, E. E.; Woodbury, G. E.

    1983-01-01

    The effects of atmospheric stability on the dispersion of primary pollutants such as CO, total hydrocarbons (THC), and NO were examined in St. Louis. The pollutant levels were measured at 25 stations, temperature at 12 stations at 5 and 30 m height, and wind speed and direction at the 30 m level at 12 stations. Correlation coefficients were generated for pairs of the vertical temperature differences, the log of the mean wind speed reciprocal, the bulk Richardson number, and specific pollutant concentrations. A high correlation was obtained between the thermal stability and the urban concentration of the primary pollutants in the lowest part of the boundary layer. A restricted nighttime dispersion of the pollutants was observed, indicating near-ground increased concentrations at times when the source emissions actually decrease.

  3. Origin, fate, and function of the components of the avian germ disc region and early blastoderm: role of ooplasmic determinants.

    PubMed

    Callebaut, Marc

    2005-08-01

    In the avian oocytal germ disc region, at the end of oogenesis, we discerned four ooplasms (alpha, beta, gamma, delta) presenting an onion-peel distribution (from peripheral and superficial to central and deep. Their fate was followed during early embryonic development. The most superficial and peripheral alpha ooplasm plays a fundamental role during cleavage. The beta ooplasm, originally localized in the peripheral region of the blastodisc, becomes mainly concentrated in the primitive streak. At the moment of bilateral symmetrization, a spatially oblique, sickle-shaped uptake of gamma and delta ooplasms occurs so that gamma and delta ooplasms become incorporated into the deeper part of the avian blastoderm. These ooplasms seem to contain ooplasmic determinants that initiate either early neurulation or gastrulation events. The early neural plate-inducing structure that forms a deep part of the blastoderm is the delta ooplasm-containing endophyll (primary hypoblast). Together with the primordial germ cells, it is derived from the superficial centrocaudal part of the nucleus of Pander, which also contains delta ooplasm. The other structure (gamma ooplasm) that is incorporated into the caudolateral deep part of the blastoderm forms Rauber's sickle. It induces gastrulation in the concavity of Rauber's sickle and blood island formation exterior to Rauber's sickle. Rauber's sickle develops by ingrowth of blastodermal cells into the gamma ooplasm, which surrounds the nucleus of Pander. Rauber's sickle constitutes the primary major organizer of the avian blastoderm and generates only extraembryonic tissues (junctional and sickle endoblast). By imparting positional information, it organizes and dominates the whole blastoderm (controlling gastrulation, neurulation, and coelom and cardiovascular system formation). Fragments of the horns of Rauber's sickle extend far cranially into the lateral quadrants of the unincubated blastoderm, so that often Rauber's sickle material

  4. Magnetic Nanodrug Delivery Through the Mucus Layer of Air-Liquid Interface Cultured Primary Normal Human Tracheobronchial Epithelial Cells

    PubMed Central

    Economou, E. C.; Marinelli, S.; Smith, M. C.; Routt, A. A.; Kravets, V. V.; Chu, H. W.; Spendier, K.; Celinski, Z. J.

    2016-01-01

    Superparamagnetic iron oxide (Fe3O4) and highly anisotropic barium hexaferrite (BaFe12O19) nanoparticles were coated with an anti-inflammatory drug and magnetically transported through mucus produced by primary human airway epithelial cells. Using wet planetary ball milling, dl-2-amino-3-phosphonopropionic acid-coated BaFe12O19 nano-particles (BaNPs) of 1–100 nm in diameter were prepared in water. BaNPs and conventional 20–30-nm Fe3O4 nanoparticles (FeNPs) were then encased in a polymer (PLGA) loaded with dexamethasone (Dex) and tagged for imaging. PLGA-Dex-coated BaNPs and FeNPs were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID) magnetometry. Both PLGA-Dex-coated BaNPs and FeNPs were transferred to the surface of a ~100-μm thick mucus layer of air-liquid interface cultured primary normal human tracheobronchial epithelial (NHTE) cells. Within 30 min, the nanoparticles were pulled successfully through the mucus layer by a permanent neodymium magnet. The penetration time of the nanomedicine was monitored using confocal microscopy and tailored by varying the thickness of the PLGA-Dex coating around the particles. PMID:27774374

  5. Layers

    NASA Astrophysics Data System (ADS)

    Hong, K. J.; Jeong, T. S.; Youn, C. J.

    2014-09-01

    The temperature-dependent photoresponse characteristics of MnAl2S4 layers have been investigated, for the first time, by use of photocurrent (PC) spectroscopy. Three peaks were observed at all temperatures. The electronic origin of these peaks was associated with band-to-band transitions from the valence-band states Γ4( z), Γ5( x), and Γ5( y) to the conduction-band state Γ1( s). On the basis of the relationship between PC-peak energy and temperature, the optical band gap could be well expressed by the expression E g( T) = E g(0) - 2.80 × 10-4 T 2/(287 + T), where E g(0) was estimated to be 3.7920 eV, 3.7955 eV, and 3.8354 eV for the valence-band states Γ4( z), Γ5( x), and Γ5( y), respectively. Results from PC spectroscopy revealed the crystal-field and spin-orbit splitting were 3.5 meV and 39.9 meV. The gradual decrease of PC intensity with decreasing temperature can be explained on the basis of trapping centers associated with native defects in the MnAl2S4 layers. Plots of log J ph, the PC current density, against 1/ T, revealed a dominant trap level in the high-temperature region. By comparing PC and the Hall effect results, we confirmed that this trap level is a shallow donor 18.9 meV below the conduction band.

  6. Treatment Option Overview (Extragonadal Germ Cell Tumors)

    MedlinePlus

    ... hCG and LDH may be at any level. Poor prognosis A nonseminoma extragonadal germ cell tumor is in the poor prognosis group if: the tumor is in the ... extragonadal germ cell tumor does not have a poor prognosis group. Treatment Option Overview Key Points There ...

  7. Peripheral facial nerve lesions induce changes in the firing properties of primary motor cortex layer 5 pyramidal cells.

    PubMed

    Múnera, A; Cuestas, D M; Troncoso, J

    2012-10-25

    Facial nerve lesions elicit long-lasting changes in vibrissal primary motor cortex (M1) muscular representation in rodents. Reorganization of cortical representation has been attributed to potentiation of preexisting horizontal connections coming from neighboring muscle representation. However, changes in layer 5 pyramidal neuron activity induced by facial nerve lesion have not yet been explored. To do so, the effect of irreversible facial nerve injury on electrophysiological properties of layer 5 pyramidal neurons was characterized. Twenty-four adult male Wistar rats were randomly subjected to two experimental treatments: either surgical transection of mandibular and buccal branches of the facial nerve (n=18) or sham surgery (n=6). Unitary and population activity of vibrissal M1 layer 5 pyramidal neurons recorded in vivo under general anesthesia was compared between sham-operated and facial nerve-injured animals. Injured animals were allowed either one (n=6), three (n=6), or five (n=6) weeks recovery before recording in order to characterize the evolution of changes in electrophysiological activity. As compared to control, facial nerve-injured animals displayed the following sustained and significant changes in spontaneous activity: increased basal firing frequency, decreased spike-associated local field oscillation amplitude, and decreased spontaneous theta burst firing frequency. Significant changes in evoked-activity with whisker pad stimulation included: increased short latency population spike amplitude, decreased long latency population oscillations amplitude and frequency, and decreased peak frequency during evoked single-unit burst firing. Taken together, such changes demonstrate that peripheral facial nerve lesions induce robust and sustained changes of layer 5 pyramidal neurons in vibrissal motor cortex. PMID:22877641

  8. The value of resequence data for poultry breeding: a primary layer breeder perspective.

    PubMed

    Fulton, Janet E

    2014-02-01

    Poultry breeding companies are facing a new paradigm. Since 2004, extensive resources have been developed to increase understanding of the fundamental biology of the chicken. The chicken genome has been sequenced and revised twice, millions of novel DNA variants have been identified, and new tools have been created that allow rapid and inexpensive detection of these DNA variations. These developments have led to the establishment of molecular-based breeding programs within major poultry breeding companies that are revolutionizing the primary poultry breeding industries. Costs of sequencing continue to drop and are predicted to eventually reach the point where it is feasible to sequence the entire genome of elite birds before selection. There are multiple challenges to be resolved before this information can be fully incorporated into a breeding program. These include handling and analyzing the extremely large data sets generated, understanding which genes, variants, or both are relevant for commercial production traits, development of new bio-informatic tools, and integration of molecular information with traditional breeding programs. The novel variation identified within elite commercial lines will lead to enhancements in commercial breeding programs. Applications of this information include whole genomic selection, parentage identification, trait association studies, and quality control. PMID:24570474

  9. The value of resequence data for poultry breeding: a primary layer breeder perspective.

    PubMed

    Fulton, Janet E

    2014-02-01

    Poultry breeding companies are facing a new paradigm. Since 2004, extensive resources have been developed to increase understanding of the fundamental biology of the chicken. The chicken genome has been sequenced and revised twice, millions of novel DNA variants have been identified, and new tools have been created that allow rapid and inexpensive detection of these DNA variations. These developments have led to the establishment of molecular-based breeding programs within major poultry breeding companies that are revolutionizing the primary poultry breeding industries. Costs of sequencing continue to drop and are predicted to eventually reach the point where it is feasible to sequence the entire genome of elite birds before selection. There are multiple challenges to be resolved before this information can be fully incorporated into a breeding program. These include handling and analyzing the extremely large data sets generated, understanding which genes, variants, or both are relevant for commercial production traits, development of new bio-informatic tools, and integration of molecular information with traditional breeding programs. The novel variation identified within elite commercial lines will lead to enhancements in commercial breeding programs. Applications of this information include whole genomic selection, parentage identification, trait association studies, and quality control.

  10. Cryopreservation of specialized chicken lines using cultured primordial germ cells.

    PubMed

    Nandi, S; Whyte, J; Taylor, L; Sherman, A; Nair, V; Kaiser, P; McGrew, M J

    2016-08-01

    Biosecurity and sustainability in poultry production requires reliable germplasm conservation. Germplasm conservation in poultry is more challenging in comparison to other livestock species. Embryo cryopreservation is not feasible for egg-laying animals, and chicken semen conservation has variable success for different chicken breeds. A potential solution is the cryopreservation of the committed diploid stem cell precursors to the gametes, the primordial germ cells ( PGCS: ). Primordial germ cells are the lineage-restricted cells found at early embryonic stages in birds and form the sperm and eggs. We demonstrate here, using flocks of partially inbred, lower-fertility, major histocompatibility complex- ( MHC-: ) restricted lines of chicken, that we can easily derive and cryopreserve a sufficient number of independent lines of male and female PGCs that would be sufficient to reconstitute a poultry breed. We demonstrate that germ-line transmission can be attained from these PGCs using a commercial layer line of chickens as a surrogate host. This research is a major step in developing and demonstrating that cryopreserved PGCs could be used for the biobanking of specialized flocks of birds used in research settings. The prospective application of this technology to poultry production will further increase sustainability to meet current and future production needs. PMID:27099306

  11. Cryopreservation of specialized chicken lines using cultured primordial germ cells

    PubMed Central

    Nandi, S.; Whyte, J.; Taylor, L.; Sherman, A.; Nair, V.; Kaiser, P.; McGrew, M. J.

    2016-01-01

    Biosecurity and sustainability in poultry production requires reliable germplasm conservation. Germplasm conservation in poultry is more challenging in comparison to other livestock species. Embryo cryopreservation is not feasible for egg-laying animals, and chicken semen conservation has variable success for different chicken breeds. A potential solution is the cryopreservation of the committed diploid stem cell precursors to the gametes, the primordial germ cells (PGCs). Primordial germ cells are the lineage-restricted cells found at early embryonic stages in birds and form the sperm and eggs. We demonstrate here, using flocks of partially inbred, lower-fertility, major histocompatibility complex- (MHC-) restricted lines of chicken, that we can easily derive and cryopreserve a sufficient number of independent lines of male and female PGCs that would be sufficient to reconstitute a poultry breed. We demonstrate that germ-line transmission can be attained from these PGCs using a commercial layer line of chickens as a surrogate host. This research is a major step in developing and demonstrating that cryopreserved PGCs could be used for the biobanking of specialized flocks of birds used in research settings. The prospective application of this technology to poultry production will further increase sustainability to meet current and future production needs. PMID:27099306

  12. Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos.

    PubMed

    Chatfield, Jodie; O'Reilly, Marie-Anne; Bachvarova, Rosemary F; Ferjentsik, Zoltan; Redwood, Catherine; Walmsley, Maggie; Patient, Roger; Loose, Mathew; Johnson, Andrew D

    2014-06-01

    A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these disparate mechanisms of PGC specification evolved is unknown. Here, in order to identify the ancestral mechanism of PGC specification in vertebrates, we studied PGC specification in embryos from the axolotl (Mexican salamander), a model for the tetrapod ancestor. In the axolotl, PGCs develop within mesoderm, and classic studies have reported their induction from primitive ectoderm (animal cap). We used an axolotl animal cap system to demonstrate that signalling through FGF and BMP4 induces PGCs. The role of FGF was then confirmed in vivo. We also showed PGC induction by Brachyury, in the presence of BMP4. These conditions induced pluripotent mesodermal precursors that give rise to a variety of somatic cell types, in addition to PGCs. Irreversible restriction of the germ line did not occur until the mid-tailbud stage, days after the somatic germ layers are established. Before this, germline potential was maintained by MAP kinase signalling. We propose that this stochastic mechanism of PGC specification, from mesodermal precursors, is conserved in vertebrates.

  13. Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos

    PubMed Central

    Chatfield, Jodie; O'Reilly, Marie-Anne; Bachvarova, Rosemary F.; Ferjentsik, Zoltan; Redwood, Catherine; Walmsley, Maggie; Patient, Roger; Loose, Mathew; Johnson, Andrew D.

    2014-01-01

    A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these disparate mechanisms of PGC specification evolved is unknown. Here, in order to identify the ancestral mechanism of PGC specification in vertebrates, we studied PGC specification in embryos from the axolotl (Mexican salamander), a model for the tetrapod ancestor. In the axolotl, PGCs develop within mesoderm, and classic studies have reported their induction from primitive ectoderm (animal cap). We used an axolotl animal cap system to demonstrate that signalling through FGF and BMP4 induces PGCs. The role of FGF was then confirmed in vivo. We also showed PGC induction by Brachyury, in the presence of BMP4. These conditions induced pluripotent mesodermal precursors that give rise to a variety of somatic cell types, in addition to PGCs. Irreversible restriction of the germ line did not occur until the mid-tailbud stage, days after the somatic germ layers are established. Before this, germline potential was maintained by MAP kinase signalling. We propose that this stochastic mechanism of PGC specification, from mesodermal precursors, is conserved in vertebrates. PMID:24917499

  14. Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos.

    PubMed

    Chatfield, Jodie; O'Reilly, Marie-Anne; Bachvarova, Rosemary F; Ferjentsik, Zoltan; Redwood, Catherine; Walmsley, Maggie; Patient, Roger; Loose, Mathew; Johnson, Andrew D

    2014-06-01

    A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these disparate mechanisms of PGC specification evolved is unknown. Here, in order to identify the ancestral mechanism of PGC specification in vertebrates, we studied PGC specification in embryos from the axolotl (Mexican salamander), a model for the tetrapod ancestor. In the axolotl, PGCs develop within mesoderm, and classic studies have reported their induction from primitive ectoderm (animal cap). We used an axolotl animal cap system to demonstrate that signalling through FGF and BMP4 induces PGCs. The role of FGF was then confirmed in vivo. We also showed PGC induction by Brachyury, in the presence of BMP4. These conditions induced pluripotent mesodermal precursors that give rise to a variety of somatic cell types, in addition to PGCs. Irreversible restriction of the germ line did not occur until the mid-tailbud stage, days after the somatic germ layers are established. Before this, germline potential was maintained by MAP kinase signalling. We propose that this stochastic mechanism of PGC specification, from mesodermal precursors, is conserved in vertebrates. PMID:24917499

  15. Cellular organization in germ tube tips of Gigaspora and its phylogenetic implications.

    PubMed

    Bentivenga, Stephen P; Kumar, T K Arun; Kumar, Leticia; Roberson, Robert W; McLaughlin, David J

    2013-01-01

    Comparative morphology of the fine structure of fungal hyphal tips often is phylogenetically informative. In particular, morphology of the Spitzenkörper varies among higher taxa. To date no one has thoroughly characterized the hyphal tips of members of the phylum Glomeromycota to compare them with other fungi. This is partly due to difficulty growing and manipulating living hyphae of these obligate symbionts. We observed growing germ tubes of Gigaspora gigantea, G. margarita and G. rosea with a combination of light microscopy (LM) and transmission electron microscopy (TEM). For TEM, we used both traditional chemical fixation and cryo-fixation methods. Germ tubes of all species were extremely sensitive to manipulation. Healthy germ tubes often showed rapid bidirectional cytoplasmic streaming, whereas germ tubes that had been disturbed showed reduced or no cytoplasmic movement. Actively growing germ tubes contain a cluster of 10-20 spherical bodies approximately 3-8 μm behind the apex. The bodies, which we hypothesize are lipid bodies, move rapidly in healthy germ tubes. These bodies disappear immediately after any cellular perturbation. Cells prepared with cryo-techniques had superior preservation compared to those that had been processed with traditional chemical protocols. For example, cryo-prepared samples displayed two cell-wall layers, at least three vesicle types near the tip and three distinct cytoplasmic zones were noted. We did not detect a Spitzenkörper with either LM or TEM techniques and the tip organization of Gigaspora germ tubes appeared to be similar to hyphae in zygomycetous fungi. This observation was supported by a phylogenetic analysis of microscopic characters of hyphal tips from members of five fungal phyla. Our work emphasizes the sensitive nature of cellular organization, and the need for as little manipulation as possible to observe germ tube structure accurately.

  16. POMB/ACE chemotherapy for mediastinal germ cell tumours.

    PubMed

    Bower, M; Brock, C; Holden, L; Nelstrop, A; Makey, A R; Rustin, G J; Newlands, E S

    1997-05-01

    Mediastinal germ cell tumours (MGCT) are rare and most published series reflect the experiences of individual institutions over many years. Since 1979, we have treated 16 men (12 non-seminomatous germ cell tumours and 4 seminomas) with newly diagnosed primary MGCT with POMB/ACE chemotherapy and elective surgical resection of residual masses. This approach yielded complete remissions in 15/16 (94%) patients. The median follow-up was 6.0 years and no relapses occurred more than 2 years after treatment. The 5 year overall survival in the non-seminomatous germ cell tumours (NSGCT) is 73% (95% confidence interval 43-90%). One patient with NSGCT developed drug-resistant disease and died without achieving remission and 2 patients died of relapsed disease. In addition, 4 patients with bulky and/or metastatic seminoma were treated with POMB/ACE. One died of treatment-related neutropenic sepsis in complete remission and one died of relapsed disease. Finally, 4 patients (2 NSGCT and 2 seminomas) referred at relapse were treated with POMB/ACE and one was successfully salvaged. The combination of POMB/ACE chemotherapy and surgery is effective management for MGCT producing high long-term survival rates.

  17. Specification of germ cell fate in mice.

    PubMed Central

    Saitou, Mitinori; Payer, Bernhard; Lange, Ulrike C; Erhardt, Sylvia; Barton, Sheila C; Surani, M Azim

    2003-01-01

    An early fundamental event during development is the segregation of germ cells from somatic cells. In many organisms, this is accomplished by the inheritance of preformed germ plasm, which apparently imposes transcriptional repression to prevent somatic cell fate. However, in mammals, pluripotent epiblast cells acquire germ cell fate in response to signalling molecules. We have used single cell analysis to study how epiblast cells acquire germ cell competence and undergo specification. Germ cell competent cells express Fragilis and initially progress towards a somatic mesodermal fate. However, a subset of these cells, the future primordial germ cells (PGCs), then shows rapid upregulation of Fragilis with concomitant transcriptional repression of a number of genes, including Hox and Smad genes. This repression may be a key event associated with germ cell specification. Furthermore, PGCs express Stella and other genes, such as Oct-4 that are associated with pluripotency. While these molecules are also detected in mature oocytes as maternally inherited factors, their early role is to regulate development and maintain pluripotency, and they do not serve the role of classical germline determinants. PMID:14511483

  18. Germ cell specification and regeneration in planarians.

    PubMed

    Newmark, P A; Wang, Y; Chong, T

    2008-01-01

    In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work.

  19. Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex

    PubMed Central

    Kida, Hiroyuki; Tsuda, Yasumasa; Ito, Nana; Yamamoto, Yui; Owada, Yuji; Kamiya, Yoshinori; Mitsushima, Dai

    2016-01-01

    Motor skill training induces structural plasticity at dendritic spines in the primary motor cortex (M1). To further analyze both synaptic and intrinsic plasticity in the layer II/III area of M1, we subjected rats to a rotor rod test and then prepared acute brain slices. Motor skill consistently improved within 2 days of training. Voltage clamp analysis showed significantly higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate (AMPA/NMDA) ratios and miniature EPSC amplitudes in 1-day trained rats compared with untrained rats, suggesting increased postsynaptic AMPA receptors in the early phase of motor learning. Compared with untrained controls, 2-days trained rats showed significantly higher miniature EPSC amplitude and frequency. Paired-pulse analysis further demonstrated lower rates in 2-days trained rats, suggesting increased presynaptic glutamate release during the late phase of learning. One-day trained rats showed decreased miniature IPSC frequency and increased paired-pulse analysis of evoked IPSC, suggesting a transient decrease in presynaptic γ-aminobutyric acid (GABA) release. Moreover, current clamp analysis revealed lower resting membrane potential, higher spike threshold, and deeper afterhyperpolarization in 1-day trained rats—while 2-days trained rats showed higher membrane potential, suggesting dynamic changes in intrinsic properties. Our present results indicate dynamic changes in glutamatergic, GABAergic, and intrinsic plasticity in M1 layer II/III neurons after the motor training. PMID:27193420

  20. Endobronchial metastasis of mixed germ cell tumors: two cases.

    PubMed

    Öztürk, Ayperi; Aktaş, Zafer; Yılmaz, Aydın

    2016-06-01

    Lung metastases from extrapulmonary malignancies are common however endobronchial metastases (EBM) from nonpulmonary neoplasms are rare. A variety of extrathoracic tumors have a tendency to EBM especially breast, colon, and renal carcinomas are most frequent reported tumors however EBM of germ cell tumors are extremely rare. A 39-year-old and a 27-year-old male patient were admitted to our hospital with hemoptysis and dyspnea at different times. Both of them had a history of left orchiectomy due to mixed germ cell tumor two years and one year ago, respectively. On chest X-Ray and thorax computed tomography, first had a right upper lobe atelectasis and second had right total atelectasis. Fiberoptic bronchoscopy (FOB) performed and a vascularized endobronchial lesion (EBL) which tended to bleed was seen in the orifis of right upper lobe in the first case and right main bronchus was totally obstructed by EBL also in the second. Interventional bronchoscopy was performed via rigid bronchoscopy for biopsy and palliative treatment (argon plasma coagulation and debulking) in both two patients because of tendency to bleeding. A partial aperture was achieved at right upper lobe bronchus in the first case and total atelectasis resolved in the second case. Immunohistochemically, histopathological examinations of both patients biopsies confirmed EBM of mixed germ cell tumors. In conclusion, EBM of the germ cell tumors especially with total or partial atelectasis are extremely rare. We want to present these cases to emphasize the importance of distinguishing EBM from primary lung carcinoma which treatment and survival could be different. PMID:27481085

  1. Left Ventricular Systolic Function Changes in Primary Hypertension Patients Detected by the Strain of Different Myocardium Layers.

    PubMed

    Huang, Jun; Yan, Zi-Ning; Rui, Yi-Fei; Fan, Li; Shen, Dan; Chen, Dong-Liang

    2016-01-01

    This study investigated left ventricular (LV) systolic dysfunction associated with differential strain among myocardial layers in primary hypertension (PH) patients with or without LV hypertrophy (LVH), and normal patients.In 63 PH and 42 healthy patients, two-dimensional speckle tracking echocardiography was used to measure the peak systolic longitudinal and circumferential strain of the myocardial subendocardial, middle and subepicardial layers, and the peak systolic radial strain. To assess LV systolic function, the apical long axis, 4- and 2-chamber views, and parasternal short axis at the basal, middle, and apical levels were acquired by cardiovascular ultrasound (Vivid E9, GE Healthcare, USA).Overall, the pattern in peak systolic longitudinal strain among myocardial layers was subendocardial > middle > subepicardial. In the peak systolic circumferential strain, this was middle > subepicardial > subendocardial. The peak systolic longitudinal strain was normal > NLVH > LVH. Among the groups, the peak systolic circumferential strain at the basal parasternal short-axis level was statistically similar, but at the middle and the apical parasternal short-axis levels were NLVH > normal > LVH. In normal and NLVH patients, the peak radial strain was middle > apical > basal, and in LVH patients was apical > middle > basal. The peak averages of the longitudinal and subendocardial circumferential strains differed significantly when LVH compared with NLVH and normal patients.The systolic function of PH patients was damaged in comparison with normal individuals, which could be detected conveniently and accurately using two-dimensional speckle tracking echocardiography.

  2. Sex determination in mammalian germ cells

    PubMed Central

    Spiller, Cassy M; Bowles, Josephine

    2015-01-01

    Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model. PMID:25791730

  3. Specifying and protecting germ cell fate

    PubMed Central

    Strome, Susan; Updike, Dustin

    2015-01-01

    Germ cells are the special cells in the body that undergo meiosis to generate gametes and subsequently entire new organisms after fertilization, a process that continues generation after generation. Recent studies have expanded our understanding of the factors and mechanisms that specify germ cell fate, including the partitioning of maternally supplied ‘germ plasm’, inheritance of epigenetic memory and expression of transcription factors crucial for primordial germ cell (PGC) development. Even after PGCs are specified, germline fate is labile and thus requires protective mechanisms, such as global transcriptional repression, chromatin state alteration and translation of only germline-appropriate transcripts. Findings from diverse species continue to provide insights into the shared and divergent needs of these special reproductive cells. PMID:26122616

  4. A specialized outer layer of the primary cell wall joins elongating cotton fibers into tissue-like bundles.

    PubMed

    Singh, Bir; Avci, Utku; Eichler Inwood, Sarah E; Grimson, Mark J; Landgraf, Jeff; Mohnen, Debra; Sørensen, Iben; Wilkerson, Curtis G; Willats, William G T; Haigler, Candace H

    2009-06-01

    Cotton (Gossypium hirsutum) provides the world's dominant renewable textile fiber, and cotton fiber is valued as a research model because of its extensive elongation and secondary wall thickening. Previously, it was assumed that fibers elongated as individual cells. In contrast, observation by cryo-field emission-scanning electron microscopy of cotton fibers developing in situ within the boll demonstrated that fibers elongate within tissue-like bundles. These bundles were entrained by twisting fiber tips and consolidated by adhesion of a cotton fiber middle lamella (CFML). The fiber bundles consolidated via the CFML ultimately formed a packet of fiber around each seed, which helps explain how thousands of cotton fibers achieve their great length within a confined space. The cell wall nature of the CFML was characterized using transmission electron microscopy, including polymer epitope labeling. Toward the end of elongation, up-regulation occurred in gene expression and enzyme activities related to cell wall hydrolysis, and targeted breakdown of the CFML restored fiber individuality. At the same time, losses occurred in certain cell wall polymer epitopes (as revealed by comprehensive microarray polymer profiling) and sugars within noncellulosic matrix components (as revealed by gas chromatography-mass spectrometry analysis of derivatized neutral and acidic glycosyl residues). Broadly, these data show that adhesion modulated by an outer layer of the primary wall can coordinate the extensive growth of a large group of cells and illustrate dynamic changes in primary wall structure and composition occurring during the differentiation of one cell type that spends only part of its life as a tissue. PMID:19369592

  5. Correlation between peripapillary retinal nerve fiber layer thickness and fundus autofluorescence in primary open-angle glaucoma

    PubMed Central

    Reznicek, Lukas; Seidensticker, Florian; Mann, Thomas; Hübert, Irene; Buerger, Alexandra; Haritoglou, Christos; Neubauer, Aljoscha S; Kampik, Anselm; Hirneiss, Christoph; Kernt, Marcus

    2013-01-01

    Purpose To investigate the relationship between retinal nerve fiber layer (RNFL) thickness and retinal pigment epithelium alterations in patients with advanced glaucomatous visual field defects. Methods A consecutive, prospective series of 82 study eyes with primary open-angle glaucoma and advanced glaucomatous visual field defects were included in this study. All study participants underwent a full ophthalmic examination followed by visual field testing with standard automated perimetry as well as spectral-domain optical coherence tomography (SD-OCT) for peripapillary RNFL thickness and Optos wide-field fundus autofluorescence (FAF) images. A pattern grid with corresponding locations between functional visual field sectors and structural peripapillary RNFL thickness was aligned to the FAF images at corresponding location. Mean FAF intensity (range: 0 = black and 255 = white) of each evaluated sector (superotemporal, temporal, inferotemporal, inferonasal, nasal, superonasal) was correlated with the corresponding peripapillary RNFL thickness obtained with SD-OCT. Results Correlation analyses between sectoral RNFL thickness and standardized FAF intensity in the corresponding topographic retina segments revealed partly significant correlations with correlation coefficients ranging between 0.004 and 0.376 and were statistically significant in the temporal inferior central field (r = 0.324, P = 0.036) and the nasal field (r = 0.376, P = 0.014). Conclusion Retinal pigment epithelium abnormalities correlate with corresponding peripapillary RNFL damage, especially in the temporal inferior sector of patients with advanced glaucomatous visual field defects. A further evaluation of FAF as a potential predictive parameter for glaucomatous damage is necessary. PMID:24092967

  6. Surgery and Combination Chemotherapy in Treating Children With Extracranial Germ Cell Tumors

    ClinicalTrials.gov

    2016-05-06

    Childhood Embryonal Tumor; Childhood Extracranial Germ Cell Tumor; Childhood Extragonadal Germ Cell Tumor; Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Childhood Teratoma; Ovarian Embryonal Carcinoma; Ovarian Yolk Sac Tumor; Stage II Malignant Testicular Germ Cell Tumor; Stage IIA Ovarian Germ Cell Tumor; Stage IIB Ovarian Germ Cell Tumor; Stage IIC Ovarian Germ Cell Tumor; Stage III Malignant Testicular Germ Cell Tumor; Stage IIIA Ovarian Germ Cell Tumor; Stage IIIB Ovarian Germ Cell Tumor; Stage IIIC Ovarian Germ Cell Tumor; Testicular Choriocarcinoma and Yolk Sac Tumor; Testicular Embryonal Carcinoma

  7. Germ Cell Tumors in Adolescents and Young Adults.

    PubMed

    Calaminus, Gabriele; Joffe, Jonathan

    2016-01-01

    Germ cell tumors (GCTs) represent a group of biologically complex malignancies that affect patients at different sites within the body and at different ages. The varying nature of these tumors reflects their cell of origin which is the primordial germ cell, which normally gives rise to ovarian and testicular egg and sperm producing cells. These cells retain an ability to give rise to all types of human tissues, and this is illustrated by the different kinds of GCTs that occur. In adolescent and young adult (AYA) patients, GCTs predominantly present as testicular, ovarian or mediastinal primary GCTs, and represent some of the most complex therapeutic challenges within any AYA practice. The varying types of GCTs, defined by primary site and/or age at presentation, can look very similar microscopically. However, there is growing evidence that they may have different molecular characteristics, different biology and different requirements for curative treatments. Whilst in adult testicular GCTs there is evidence for an environmental cause during fetal development and a genetic component, these causative factors are much less well understood in other GCTs. GCTs are some of the most curable cancers in adults, but some patients exhibit resistance to standard treatments. Because of this, today's clinical research is directed at understanding how to best utilize toxic therapies and promote healthy survivorship. This chapter explores the biology, behavior and treatment of GCTs and discusses how the AYA group of GCTs may hold some of the keys to understanding fundamental unanswered questions of biological variance and curability in GCTs. PMID:27595361

  8. Thin-layer chromatographic analysis of myelin lipids, their differential O-deacylation by primary alkylamines and their selective staining by thionine. A limited phylogenetic study.

    PubMed

    Hack, M H; Helmy, F M

    1990-02-23

    A silica gel thin-layer chromatographic procedure is described for the study of the myelin lipid patterns in a small phylogenetic series of nerve tissue specimens. It involves the selective staining by the thiazine dye thionine and the interpretations were facilitated by a preceding primary alkylamine O-deacylation step. Glycolipids, including sulfatides, and ethanolamine plasmalogens were the principal characterizing lipids.

  9. Genetic Mosaics and the Germ Line Lineage

    PubMed Central

    Samuels, Mark E.; Friedman, Jan M.

    2015-01-01

    Genetic mosaics provide information about cellular lineages that is otherwise difficult to obtain, especially in humans. De novo mutations act as cell markers, allowing the tracing of developmental trajectories of all descendants of the cell in which the new mutation arises. De novo mutations may arise at any time during development but are relatively rare. They have usually been observed through medical ascertainment, when the mutation causes unusual clinical signs or symptoms. Mutational events can include aneuploidies, large chromosomal rearrangements, copy number variants, or point mutations. In this review we focus primarily on the analysis of point mutations and their utility in addressing questions of germ line versus somatic lineages. Genetic mosaics demonstrate that the germ line and soma diverge early in development, since there are many examples of combined somatic and germ line mosaicism for de novo mutations. The occurrence of simultaneous mosaicism in both the germ line and soma also shows that the germ line is not strictly clonal but arises from at least two, and possibly multiple, cells in the embryo with different ancestries. Whole genome or exome DNA sequencing technologies promise to expand the range of studies of genetic mosaics, as de novo mutations can now be identified through sequencing alone in the absence of a medical ascertainment. These technologies have been used to study mutation patterns in nuclear families and in monozygotic twins, and in animal model developmental studies, but not yet for extensive cell lineage studies in humans. PMID:25898403

  10. Paediatric extracranial germ-cell tumours.

    PubMed

    Shaikh, Furqan; Murray, Matthew J; Amatruda, James F; Coleman, Nicholas; Nicholson, James C; Hale, Juliet P; Pashankar, Farzana; Stoneham, Sara J; Poynter, Jenny N; Olson, Thomas A; Billmire, Deborah F; Stark, Daniel; Rodriguez-Galindo, Carlos; Frazier, A Lindsay

    2016-04-01

    Management of paediatric extracranial germ-cell tumours carries a unique set of challenges. Germ-cell tumours are a heterogeneous group of neoplasms that present across a wide age range and vary in site, histology, and clinical behaviour. Patients with germ-cell tumours are managed by a diverse array of specialists. Thus, staging, risk stratification, and treatment approaches for germ-cell tumours have evolved disparately along several trajectories. Paediatric germ-cell tumours differ from the adolescent and adult disease in many ways, leading to complexities in applying age-appropriate, evidence-based care. Suboptimal outcomes remain for several groups of patients, including adolescents, and patients with extragonadal tumours, high tumour markers at diagnosis, or platinum-resistant disease. Survivors have significant long-term toxicities. The challenge moving forward will be to translate new insights from molecular studies and collaborative clinical data into improved patient outcomes. Future trials will be characterised by improved risk-stratification systems, biomarkers for response and toxic effects, rational reduction of therapy for low-risk patients and novel approaches for poor-risk patients, and improved international collaboration across paediatric and adult cooperative research groups. PMID:27300675

  11. Male germ cell transplantation in livestock.

    PubMed

    Hill, J R; Dobrinski, I

    2006-01-01

    Male germ cell transplantation is a powerful approach to study the control of spermatogenesis with the ultimate goal to enhance or suppress male fertility. In livestock animals, applications can be expanded to provide an alternative method of transgenesis and an alternative means of artificial insemination (AI). The transplantation technique uses testis stem cells, harvested from the donor animal. These donor stem cells are injected into seminiferous tubules, migrate from the lumen to relocate to the basement membrane and, amazingly, they can retain the capability to produce donor sperm in their new host. Adaptation of the mouse technique for livestock is progressing, with gradual gains in efficiency. Germ cell transfer in goats has produced offspring, but not yet in cattle and pigs. In goats and pigs, the applications of germ cell transplantation are mainly in facilitating transgenic animal production. In cattle, successful male germ cell transfer could create an alternative to AI in areas where it is impractical. Large-scale culture of testis stem cells would enhance the use of elite bulls by providing a renewable source of stem cells for transfer. Although still in a developmental state, germ cell transplantation is an emerging technology with the potential to create new opportunities in livestock production. PMID:16478598

  12. Assessing similarity to primary tissue and cortical layer identity in induced pluripotent stem cell-derived cortical neurons through single-cell transcriptomics

    PubMed Central

    Handel, Adam E.; Chintawar, Satyan; Lalic, Tatjana; Whiteley, Emma; Vowles, Jane; Giustacchini, Alice; Argoud, Karene; Sopp, Paul; Nakanishi, Mahito; Bowden, Rory; Cowley, Sally; Newey, Sarah; Akerman, Colin; Ponting, Chris P.; Cader, M. Zameel

    2016-01-01

    Induced pluripotent stem cell (iPSC)-derived cortical neurons potentially present a powerful new model to understand corticogenesis and neurological disease. Previous work has established that differentiation protocols can produce cortical neurons, but little has been done to characterize these at cellular resolution. In particular, it is unclear to what extent in vitro two-dimensional, relatively disordered culture conditions recapitulate the development of in vivo cortical layer identity. Single-cell multiplex reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) was used to interrogate the expression of genes previously implicated in cortical layer or phenotypic identity in individual cells. Totally, 93.6% of single cells derived from iPSCs expressed genes indicative of neuronal identity. High proportions of single neurons derived from iPSCs expressed glutamatergic receptors and synaptic genes. And, 68.4% of iPSC-derived neurons expressing at least one layer marker could be assigned to a laminar identity using canonical cortical layer marker genes. We compared single-cell RNA-seq of our iPSC-derived neurons to available single-cell RNA-seq data from human fetal and adult brain and found that iPSC-derived cortical neurons closely resembled primary fetal brain cells. Unexpectedly, a subpopulation of iPSC-derived neurons co-expressed canonical fetal deep and upper cortical layer markers. However, this appeared to be concordant with data from primary cells. Our results therefore provide reassurance that iPSC-derived cortical neurons are highly similar to primary cortical neurons at the level of single cells but suggest that current layer markers, although effective, may not be able to disambiguate cortical layer identity in all cells. PMID:26740550

  13. "Life in a Germ-Free World":

    PubMed Central

    Kirk, Robert G. W.

    2012-01-01

    Summary: This article examines a specific technology, the germ-free "isolator," tracing its development across three sites: (1) the laboratory for the production of standard laboratory animals, (2) agriculture for the efficient production of farm animals, and (3) the hospital for the control and prevention of cross-infection and the protection of individuals from infection. Germ-free technology traveled across the laboratory sciences, clinical and veterinary medicine, and industry, yet failed to become institutionalized outside the laboratory. That germ-free technology worked was not at issue. Working, however, was not enough. Examining the history of a technology that failed to find widespread application reveals the labor involved in aligning cultural, societal, and material factors necessary for successful medical innovation. PMID:23000838

  14. Elucidating human male germ cell development by studying germ cell cancer.

    PubMed

    Nettersheim, Daniel; Jostes, Sina; Schneider, Simon; Schorle, Hubert

    2016-10-01

    Human germ cell development is regulated in a spatio-temporal manner by complex regulatory networks. Here, we summarize results obtained in germ cell tumors and respective cell lines and try to pinpoint similarities to normal germ cell development. This comparison allows speculating about the critical and error-prone mechanisms, which when disturbed, lead to the development of germ cell tumors. Short after specification, primordial germ cells express markers of pluripotency, which, in humans, persists up to the stage of fetal/infantile spermatogonia. Aside from the rare spermatocytic tumors, virtually all seminomas and embryonal carcinomas express markers of pluripotency and show signs of pluripotency or totipotency. Therefore, it appears that proper handling of the pluripotency program appears to be the most critical step in germ cell development in terms of tumor biology. Furthermore, data from mice reveal that germline cells display an epigenetic signature, which is highly similar to pluripotent cells. This signature (poised histone code, DNA hypomethylation) is required for the rapid induction of toti- and pluripotency upon fertilization. We propose that adult spermatogonial cells, when exposed to endocrine disruptors or epigenetic active substances, are prone to reinitiate the pluripotency program, giving rise to a germ cell tumor. The fact that pluripotent cells can be derived from adult murine and human testicular cells further corroborates this idea. PMID:27512122

  15. Germ Line Mechanics--And Unfinished Business.

    PubMed

    Wessel, Gary M

    2016-01-01

    Primordial germ cells are usually made early in the development of an organism. These are the mother of all stem cells that are necessary for propagation of the species, yet use highly diverse mechanisms between organisms. How they are specified, and when and where they form, are central to developmental biology. Using diverse organisms to study this development is illuminating for understanding the mechanics these cells use in this essential function and for identifying the breadth of evolutionary changes that have occurred between species. This essay emphasizes how echinoderms may contribute to the patchwork quilt of our understanding of germ line formation during embryogenesis. PMID:26970000

  16. Germ line mechanics – and unfinished business

    PubMed Central

    Wessel, Gary M.

    2016-01-01

    Primordial germ cells are usually made early in the development of an organism. These are the mother of all stem cells that are necessary for propagation of the species, yet use highly diverse mechanisms between organisms. How they are specified, and when and where they form, are central to developmental biology. Using diverse organisms to study this development is illuminating for understanding the mechanics these cells use in this essential function, and for identifying the breadth of evolutionary changes that have occurred between species. This essay emphasizes how echinoderms may contribute to the patch-work quilt of our understanding of germ line formation during embryogenesis. PMID:26970000

  17. General Information about Childhood Extracranial Germ Cell Tumors

    MedlinePlus

    ... Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Childhood Extracranial Germ Cell Tumors Go to ... the PDQ Pediatric Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  18. GERM as a tool for space station documentation

    NASA Technical Reports Server (NTRS)

    Crouse, Ken; Hardwick, Charles

    1990-01-01

    GERM as a tool for space station documentation is presented in the form of viewgraphs. The following subject areas are covered: problem statement, hypermedia as a tool for documentation, description of GERM, technical approach, application development, and results and conclusions.

  19. Tips for Avoiding Back-To-School Germs, Illnesses

    MedlinePlus

    ... it takes to sing the alphabet would help kill a lot of germs." Children should also be ... child's class with some antibacterial wipes to help kill germs on their desk or work stations," Stout- ...

  20. Signaling events during male germ cell differentiation: bases and perspectives.

    PubMed

    Berruti, G

    1998-11-01

    In all species, reproductive function depends on the ability of the individual to produce functional differentiated gametes. Spermatogenesis is a cyclic process in which diploid spermatogonia differentiate into mature haploid spermatozoa. Thus from a genetic point of view, spermatogenesis can be divided into two phases, namely the diploid and haploid phase. Indeed, this complex differentiation process is still more intriguing since primary spermatocytes, if genetically diploid, are functionally tetraploid, while elongating spermatids, the germ cells undergoing the most dramatic morphological changes, if genetically haploid, become functionally anucleate due to ongoing condensation of chromatin resulting in an inactive nuclear DNA. This multi-step differentiative pathway is dependent on a specific environment provided by the anatomical and cellular relationships that take place in the testis and more specifically within the seminiferous tubules. Already, early anatomists (mind comes to Enrico Sertoli and Gustaf Retzius) were fascinated by the mixed cellular composition of the testis correctly deciphered as a whole of interacting and interdependent cell types despite the fact these belong to two well-established and different cell lineages, i.e, the somatic and germinal line. Since their time (the XIX century) up to-day a conspicuous bulk of experimental work and a relative massive bibliographic documentation have been provided. From this it stands out : a) a sophisticated role played by the cyclic hormonal control elicited by the hypothalamic-pituitary axis; b) the structural membrane specializations of Sertoli-germ cell communications; c) the existence and action of a paracrine and autocrine testicular regulative secretion; d) a regulation of germ cell gene expression, highly specialized both at transcriptional, posttranscriptional, and translational level; e) an active participation of the haploid genome in the final steps of cell differentiation. Each of these

  1. Galactic Cosmic Ray Event-Based Risk Model (GERM) Code

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Plante, Ianik; Ponomarev, Artem L.; Kim, Myung-Hee Y.

    2013-01-01

    physical and biophysical quantities of high-energy protons and heavy ions that have been studied at the NASA Space Radiation Laboratory (NSRL) for the purpose of simulating space radiation biological effects. In the first option, properties of monoenergetic beams are treated. In the second option, the transport of beams in different materials is treated. Similar biophysical properties as in the first option are evaluated for the primary ion and its secondary particles. Additional properties related to the nuclear fragmentation of the beam are evaluated. The GERM code is a computationally efficient Monte-Carlo heavy-ion-beam model. It includes accurate models of LET, range, residual energy, and straggling, and the quantum multiple scattering fragmentation (QMSGRG) nuclear database.

  2. Characterization of the functional properties of carob germ proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins from the carob germ were identified as having gluten-like proteins in 1935. While some biochemical characterization of carob germ proteins and their functionality has been carried out, relatively little has been done when compared to proteins such as gluten. Carob germ proteins were separ...

  3. Improvement of dry fractionation ethanol fermentation by partial germ supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethanol fermentation of dry fractionated grits (corn endosperm pieces) containing different levels of germ was studied using the dry grind process. Partial removal of germ fraction allows for marketing the germ fraction and potentially more efficient fermentation. Grits obtained from a dry milling p...

  4. Germ plasm biogenesis –an Oskar-centric perspective

    PubMed Central

    Lehmann, Ruth

    2016-01-01

    Germ granules are the hallmark of all germ cells. These membrane-less, electron-dense structures were first observed over 100 years ago. Today, their role in regulating and processing transcripts critical for the establishment, maintenance and protection of germ cells is well-established and pathways outlining the biochemical mechanisms and physical properties associated with their biogenesis are emerging. PMID:26970648

  5. Colleges Put the Squeeze on Germs

    ERIC Educational Resources Information Center

    Sander, Libby

    2008-01-01

    A spirited campaign to promote "hand hygiene" is under way at the University of Central Florida Orlando campus, and the urinal toter, known as UCF 5th Guy, is its front line. Like their counterparts at many other institutions, health officials at Central Florida want students to think about the germs that lurk on their hands. And then clean them,…

  6. Germ Smart: Children's Activities in Disease Prevention.

    ERIC Educational Resources Information Center

    Scheer, Judith K.

    This booklet is part of the "Children's Activity Series," a set of four supplemental teaching resources that promote awareness about health, family life, and cultural diversity for children in kindergarten through third grade. Nine activities are included in this booklet to help children be "germ smart" help children in kindergarten through third…

  7. Germ Cells Need Folate to Proliferate.

    PubMed

    Walker, Amy K

    2016-07-11

    In this issue of Developmental Cell, Chaudhari and colleagues (2016) use a novel method to create an in vitro proliferative cell line from tumorous C. elegans germ cells, and in the process discover that bacterial folates act as signals for proliferation, independent of their roles as vitamins. PMID:27404353

  8. Implications of Sertoli cell induced germ cell apoptosis to testicular pathology

    PubMed Central

    Murphy, Caitlin J; Richburg, John H

    2014-01-01

    After exposure to toxicants, degenerating germ cells represents the most common testicular histopathological alteration, regardless of the mechanism of toxicity. Therefore, deciphering the primary toxicant cellular target and mechanism of action can be extremely difficult. However, most testicular toxicants display a cell-specific and a stage-specific pattern of damage, which is the best evidence for identifying the primary cellular target (i.e. germ cell, Sertoli cell, peritubular myoid cell, or Leydig cell). Some toxicant-induced Sertoli cell injury presents with germ cell apoptosis occurring primarily in spermatocytes in rats in stages XI-XIV, I and II. Although some toxicants result in spermatid degeneration and apoptosis, it is still unclear if spermatid apoptosis is a result of Sertoli cell-selective apoptosis or a direct effect of toxicants on spermatids, therefore if this is seen as the earliest change, one cannot infer the mechanism of apoptosis. This review summarizes some of the distinguishing features of Sertoli cell-induced germ cell apoptosis and the associated mechanisms of cell death to provide the toxicologist observing similar cell death, with evidence about a potential mode of action. PMID:26413394

  9. [Studies on primary aromatic amines (PAAs) migration from multi-layer plastic food packaging by HPLC method].

    PubMed

    Cwiek-Ludwicka, Kazimiera; Pawlicka, Marzena; Starski, Andrzej; Półtorak, Hanna; Karłowski, Kazimierz

    2011-01-01

    The aim of this study was to identify of primary aromatic amines (PAAs) and to determine their migration from plastic food packaging. The magnitude of the migration of these substances from plastic food packaging consists a base for the evaluation of their compliance with the requirements of EU legislation and hazard for human health taking into account their migration into food. The unprinted and printed multi-layer plastic packaging (laminates), domestic and imported, were examined in these studies. PAAs migration tests from the laminates into food simulant (3% acetic acid) was performed according to the appropriate procedures recommended in the EU for testing migration from food contact articles under standard conditions reflecting the real use of laminates (10 days, 40 degrees C) and under ,, worst case scenario" conditions (2 h, 70 degrees C). PAAs present in migration solutions were concentrated on SPE columns and then seven PAAs (aniline, 1,3-phenylenediamine, 2, 6-toluenediamine, 2,4-toluenediamine, 4,4'-oxydianiline, 4,4'-methylenedianiline and 3,3 '-dimethylbenzidyne) were identified and determined by previously validated HPLC-DAD method. Depending on the migration conditions the PAAs content was different. When the "worst case scenario" conditions were applied the migration of 4,4 '-methylenedianiline (4,4 '-MDA) ranged from below detection limit (LOD = 0.51 microg/kg) up to 9.86 microg/kg, and aniline was released in the range from below detection limit (LOD = 0,98 microg/kg) up to 7.04 microg/kg. In two laminate samples of eight examined, the sum of PAAs (aniline and 4,4'-MDA) was 13.32 microg/kg and 14.72 microg/kg showing that the permitted limit (10 microg/kg) was exceeded. In the standard conditions, the migration of aniline and 4,4'-MDA was significantly lower Regarding the carcinogenic potential of PAAs, the laminates causing the amines migration above the permitted limit should not be used as food packaging.

  10. A germ cell determinant reveals parallel pathways for germ line development in Caenorhabditis elegans.

    PubMed

    Mainpal, Rana; Nance, Jeremy; Yanowitz, Judith L

    2015-10-15

    Despite the central importance of germ cells for transmission of genetic material, our understanding of the molecular programs that control primordial germ cell (PGC) specification and differentiation are limited. Here, we present findings that X chromosome NonDisjunction factor-1 (XND-1), known for its role in regulating meiotic crossover formation, is an early determinant of germ cell fates in Caenorhabditis elegans. xnd-1 mutant embryos display a novel 'one PGC' phenotype as a result of G2 cell cycle arrest of the P4 blastomere. Larvae and adults display smaller germ lines and reduced brood size consistent with a role for XND-1 in germ cell proliferation. Maternal XND-1 proteins are found in the P4 lineage and are exclusively localized to the nucleus in PGCs, Z2 and Z3. Zygotic XND-1 turns on shortly thereafter, at the ∼300-cell stage, making XND-1 the earliest zygotically expressed gene in worm PGCs. Strikingly, a subset of xnd-1 mutants lack germ cells, a phenotype shared with nos-2, a member of the conserved Nanos family of germline determinants. We generated a nos-2 null allele and show that nos-2; xnd-1 double mutants display synthetic sterility. Further removal of nos-1 leads to almost complete sterility, with the vast majority of animals without germ cells. Sterility in xnd-1 mutants is correlated with an increase in transcriptional activation-associated histone modification and aberrant expression of somatic transgenes. Together, these data strongly suggest that xnd-1 defines a new branch for PGC development that functions redundantly with nos-2 and nos-1 to promote germline fates by maintaining transcriptional quiescence and regulating germ cell proliferation. PMID:26395476

  11. Ectopic expression of Cvh (Chicken Vasa homologue) mediates the reprogramming of chicken embryonic stem cells to a germ cell fate.

    PubMed

    Lavial, Fabrice; Acloque, Hervé; Bachelard, Elodie; Nieto, M Angela; Samarut, Jacques; Pain, Bertrand

    2009-06-01

    When they are derived from blastodermal cells of the pre-primitive streak in vitro, the pluripotency of Chicken Embryonic Stem Cells (cESC) can be controlled by the cPouV and Nanog genes. These cESC can differentiate into derivatives of the three germ layers both in vitro and in vivo, but they only weakly colonize the gonads of host embryos. By contrast, non-cultured blastodermal cells and long-term cultured chicken primordial germ cells maintain full germline competence. This restriction in the germline potential of the cESC may result from either early germline determination in the donor embryos or it may occur as a result of in vitro culture. We are interested in understanding the genetic determinants of germline programming. The RNA binding protein Cvh (Chicken Vasa Homologue) is considered as one such determinant, although its role in germ cell physiology is still unclear. Here we show that the exogenous expression of Cvh, combined with appropriate culture conditions, induces cESC reprogramming towards a germ cell fate. Indeed, these cells express the Dazl, Tudor and Sycp3 germline markers, and they display improved germline colonization and adopt a germ cell fate when injected into recipient embryos. Thus, our results demonstrate that Vasa can drive ES cell differentiation towards the germ cell lineage, both in vitro and in vivo.

  12. Germ-line p53 mutations in 15 families with Li-Fraumeni syndrome

    SciTech Connect

    Frebourg, T.; Barbier, N.; Yan, Yu-xin; Friend, S.H. |; Garber, J.E.; Dreyfus, M.; Li, F.P.; Fraumeni, J. Jr.

    1995-03-01

    Germ-line mutations of the tumor-suppressor gene p53 have been observed in some families with the Li-Fraumeni syndrome (LFS), a familial cancer syndrome in which affected relatives develop a diverse set of early-onset malignancies including breast carcinoma, sarcomas, and brain tumors. The analysis of the p53 gene in LFS families has been limited, in most studies to date, to the region between exon 5 and exon 9. In order to determine the frequency and distribution of germ-line p53 mutations in LFS, we sequenced the 10 coding exons of the p53 gene in lymphocytes and fibroblast cell lines derived from 14 families with the syndrome. Germ-line mutations were observed in eight families. Six mutations were missense mutations located between exons 5 and 8. One mutation was a nonsense mutation in exon 6, and one mutation was a splicing mutation in intron 4, generating aberrant shorter p53 RNA(s). In three families, a mutation of the p53 gene was observed in the fibroblast cell line derived from the proband. However, the mutation was not found in affected relatives in two families and in the blood from the one individual, indicating that the mutation probably occurred during cell culture in vitro. In four families, no mutation was observed. This study indicates that germ-line p53 mutations in LFS are mostly located between exons 5 and 8 and that {approximately}50% of patients with LFS have no germ-line mutations in the coding region of the p53 gene. The observation of p53 mutations occurring during primary cultures of human fibroblasts shows that analysis for germ-line p53 mutations must be performed on cells that have not been grown in vitro. 49 refs., 1 fig., 4 tabs.

  13. Extraction and demulsification of oil from wheat germ, barley germ, and rice bran using an aqueous enzymatic method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An aqueous enzymatic method was developed to extract oil from wheat germ. The parameters that influence oil yield were investigated, including wheat germ pretreatment, comparison of various industrial enzymes, pH, ratio of wheat germ to water, reaction time and demulsification. Pretreatment at 180ºC...

  14. Re-irradiation of Recurrent Pineal Germ Cell Tumors with Radiosurgery: Report of Two Cases and Review of Literature.

    PubMed

    Wong, Kenneth; Opimo, Anthony B; Olch, Arthur J; All, Sean; Waxer, Jonathan F; Clark, Desirae; Cheng, Justine; Chlebik, Alisha; Erdreich-Epstein, Anat; Krieger, Mark D; Tamrazi, Benita; Dhall, Girish; Finlay, Jonathan L; Chang, Eric L

    2016-01-01

    Primary intracranial germ cell tumors are rare, representing less than 5% of all central nervous system tumors. Overall, the majority of germ cell tumors are germinomas and approximately one-third are non-germinomatous germ cell tumors (NGGCT), which include teratoma, embryonal carcinoma, yolk sac tumor (endodermal sinus tumor), choriocarcinoma, or mixed malignant germ cell tumor. Germ cell tumors may secrete detectable levels of proteins into the blood and/or cerebrospinal fluid, and these proteins can be used for diagnostic purposes or to monitor tumor recurrence. Germinomas have long been known to be highly curable with radiation therapy alone. However, many late effects of whole brain or craniospinal irradiation have been well documented. Strategies have been developed to reduce the dose and volume of radiation therapy, often in combination with chemotherapy. In contrast, patients with NGGCT have a poorer prognosis, with about 60% cured with multimodality chemoradiation. There are no standard approaches for relapsed germ cell tumors. Options may be limited by prior treatment. Radiation therapy has been utilized alone or in combination with chemotherapy or high-dose chemotherapy and transplant. We discuss two cases and review options for frameless radiosurgery or fractionated radiotherapy. PMID:27239400

  15. Re-irradiation of Recurrent Pineal Germ Cell Tumors with Radiosurgery: Report of Two Cases and Review of Literature

    PubMed Central

    Opimo, Anthony B; Olch, Arthur J; All, Sean; Waxer, Jonathan F; Clark, Desirae; Cheng, Justine; Chlebik, Alisha; Erdreich-Epstein, Anat; Krieger, Mark D; Tamrazi, Benita; Dhall, Girish; Finlay, Jonathan L; Chang, Eric L

    2016-01-01

    Primary intracranial germ cell tumors are rare, representing less than 5% of all central nervous system tumors. Overall, the majority of germ cell tumors are germinomas and approximately one-third are non-germinomatous germ cell tumors (NGGCT), which include teratoma, embryonal carcinoma, yolk sac tumor (endodermal sinus tumor), choriocarcinoma, or mixed malignant germ cell tumor. Germ cell tumors may secrete detectable levels of proteins into the blood and/or cerebrospinal fluid, and these proteins can be used for diagnostic purposes or to monitor tumor recurrence. Germinomas have long been known to be highly curable with radiation therapy alone. However, many late effects of whole brain or craniospinal irradiation have been well documented. Strategies have been developed to reduce the dose and volume of radiation therapy, often in combination with chemotherapy. In contrast, patients with NGGCT have a poorer prognosis, with about 60% cured with multimodality chemoradiation. There are no standard approaches for relapsed germ cell tumors. Options may be limited by prior treatment. Radiation therapy has been utilized alone or in combination with chemotherapy or high-dose chemotherapy and transplant. We discuss two cases and review options for frameless radiosurgery or fractionated radiotherapy. PMID:27239400

  16. Layer 5 Pyramidal Neurons' Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis.

    PubMed

    Urrego, Diana; Troncoso, Julieta; Múnera, Alejandro

    2015-01-01

    This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3 weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1). It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans.

  17. Testicular histology and germ cell cytology during spermatogenesis in the Mississippi map turtle, Graptemys pseudogeographica kohnii, from Northeast Arkansas

    PubMed Central

    Lancaster, Kelsey; Trauth, Stanley E; Gribbins, Kevin M

    2014-01-01

    The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year

  18. The biology of the germ line in echinoderms.

    PubMed

    Wessel, Gary M; Brayboy, Lynae; Fresques, Tara; Gustafson, Eric A; Oulhen, Nathalie; Ramos, Isabela; Reich, Adrian; Swartz, S Zachary; Yajima, Mamiko; Zazueta, Vanessa

    2014-08-01

    The formation of the germ line in an embryo marks a fresh round of reproductive potential. The developmental stage and location within the embryo where the primordial germ cells (PGCs) form, however, differs markedly among species. In many animals, the germ line is formed by an inherited mechanism, in which molecules made and selectively partitioned within the oocyte drive the early development of cells that acquire this material to a germ-line fate. In contrast, the germ line of other animals is fated by an inductive mechanism that involves signaling between cells that directs this specialized fate. In this review, we explore the mechanisms of germ-line determination in echinoderms, an early-branching sister group to the chordates. One member of the phylum, sea urchins, appears to use an inherited mechanism of germ-line formation, whereas their relatives, the sea stars, appear to use an inductive mechanism. We first integrate the experimental results currently available for germ-line determination in the sea urchin, for which considerable new information is available, and then broaden the investigation to the lesser-known mechanisms in sea stars and other echinoderms. Even with this limited insight, it appears that sea stars, and perhaps the majority of the echinoderm taxon, rely on inductive mechanisms for germ-line fate determination. This enables a strongly contrasted picture for germ-line determination in this phylum, but one for which transitions between different modes of germ-line determination might now be experimentally addressed.

  19. The Biology of the Germ line in Echinoderms

    PubMed Central

    Wessel, Gary M.; Brayboy, Lynae; Fresques, Tara; Gustafson, Eric A.; Oulhen, Nathalie; Ramos, Isabela; Reich, Adrian; Swartz, S. Zachary; Yajima, Mamiko; Zazueta, Vanessa

    2014-01-01

    SUMMARY The formation of the germ line in an embryo marks a fresh round of reproductive potential. The developmental stage and location within the embryo where the primordial germ cells (PGCs) form, however, differs markedly among species. In many animals, the germ line is formed by an inherited mechanism, in which molecules made and selectively partitioned within the oocyte drive the early development of cells that acquire this material to a germ-line fate. In contrast, the germ line of other animals is fated by an inductive mechanism that involves signaling between cells that directs this specialized fate. In this review, we explore the mechanisms of germ-line determination in echinoderms, an early-branching sister group to the chordates. One member of the phylum, sea urchins, appears to use an inherited mechanism of germ-line formation, whereas their relatives, the sea stars, appear to use an inductive mechanism. We first integrate the experimental results currently available for germ line determination in the sea urchin, for which considerable new information is available, and then broaden the investigation to the lesser-known mechanisms in sea stars and other echinoderms. Even with this limited insight, it appears that sea stars, and perhaps the majority of the echinoderm taxon, rely on inductive mechanisms for germ-line fate determination. This enables a strongly contrasted picture for germ-line determination in this phylum, but one for which transitions between different modes of germ-line determination might now be experimentally addressed. PMID:23900765

  20. Approaches for identifying germ cell mutagens: Report of the 2013 IWGT workshop on germ cell assays(☆).

    PubMed

    Yauk, Carole L; Aardema, Marilyn J; Benthem, Jan van; Bishop, Jack B; Dearfield, Kerry L; DeMarini, David M; Dubrova, Yuri E; Honma, Masamitsu; Lupski, James R; Marchetti, Francesco; Meistrich, Marvin L; Pacchierotti, Francesca; Stewart, Jane; Waters, Michael D; Douglas, George R

    2015-05-01

    This workshop reviewed the current science to inform and recommend the best evidence-based approaches on the use of germ cell genotoxicity tests. The workshop questions and key outcomes were as follows. (1) Do genotoxicity and mutagenicity assays in somatic cells predict germ cell effects? Limited data suggest that somatic cell tests detect most germ cell mutagens, but there are strong concerns that dictate caution in drawing conclusions. (2) Should germ cell tests be done, and when? If there is evidence that a chemical or its metabolite(s) will not reach target germ cells or gonadal tissue, it is not necessary to conduct germ cell tests, notwithstanding somatic outcomes. However, it was recommended that negative somatic cell mutagens with clear evidence for gonadal exposure and evidence of toxicity in germ cells could be considered for germ cell mutagenicity testing. For somatic mutagens that are known to reach the gonadal compartments and expose germ cells, the chemical could be assumed to be a germ cell mutagen without further testing. Nevertheless, germ cell mutagenicity testing would be needed for quantitative risk assessment. (3) What new assays should be implemented and how? There is an immediate need for research on the application of whole genome sequencing in heritable mutation analysis in humans and animals, and integration of germ cell assays with somatic cell genotoxicity tests. Focus should be on environmental exposures that can cause de novo mutations, particularly newly recognized types of genomic changes. Mutational events, which may occur by exposure of germ cells during embryonic development, should also be investigated. Finally, where there are indications of germ cell toxicity in repeat dose or reproductive toxicology tests, consideration should be given to leveraging those studies to inform of possible germ cell genotoxicity.

  1. How free of germs is germ-free? Detection of bacterial contamination in a germ free mouse unit

    PubMed Central

    Fontaine, Clinton A; Skorupski, Anna M; Vowles, Chriss J; Anderson, Natalie E; Poe, Sara A; Eaton, Kathryn A

    2015-01-01

    Management of germ free animals has changed little since the beginning of the 20th century. The current upswing in their use, however, has led to interest in improved methods of screening and housing. Traditionally, germ free colonies are screened for bacterial colonization by culture and examination of Gram stained fecal samples, but some investigators have reported using PCR-based methods of microbial detection, presumably because of perceived increased sensitivity. The accuracy and detection limit for traditional compared to PCR-based screening assays are not known. The purpose of this study was to determine the limit of detection of bacterial contamination of mouse feces by aerobic and anaerobic culture, Gram stain, and qPCR, and to compare the accuracy of these tests in the context of a working germ free mouse colony. We found that the limit of detection for qPCR (approximately 105 cfu/g of feces) was lower than for Gram stain (approximately 109 cfu/g), but that all 3 assays were of similar accuracy. Bacterial culture was the most sensitive, but the least specific, and qPCR was the least sensitive and most specific. Gram stain but not qPCR detected heat-killed bacteria, indicating that bacteria in autoclaved diet are unlikely to represent a potential confounding factor for PCR screening. We conclude that as a practical matter, bacterial culture and Gram stain are adequate for screening germ free mouse colonies for bacterial contaminants, but that should low numbers of unculturable bacteria be present, they would not be detected with any of the currently available means. PMID:26018301

  2. How free of germs is germ-free? Detection of bacterial contamination in a germ free mouse unit.

    PubMed

    Fontaine, Clinton A; Skorupski, Anna M; Vowles, Chriss J; Anderson, Natalie E; Poe, Sara A; Eaton, Kathryn A

    2015-07-01

    Management of germ free animals has changed little since the beginning of the 20th century. The current upswing in their use, however, has led to interest in improved methods of screening and housing. Traditionally, germ free colonies are screened for bacterial colonization by culture and examination of Gram stained fecal samples, but some investigators have reported using PCR-based methods of microbial detection, presumably because of perceived increased sensitivity. The accuracy and detection limit for traditional compared to PCR-based screening assays are not known. The purpose of this study was to determine the limit of detection of bacterial contamination of mouse feces by aerobic and anaerobic culture, Gram stain, and qPCR, and to compare the accuracy of these tests in the context of a working germ free mouse colony. We found that the limit of detection for qPCR (approximately 10(5) cfu/g of feces) was lower than for Gram stain (approximately 10(9) cfu/g), but that all 3 assays were of similar accuracy. Bacterial culture was the most sensitive, but the least specific, and qPCR was the least sensitive and most specific. Gram stain but not qPCR detected heat-killed bacteria, indicating that bacteria in autoclaved diet are unlikely to represent a potential confounding factor for PCR screening. We conclude that as a practical matter, bacterial culture and Gram stain are adequate for screening germ free mouse colonies for bacterial contaminants, but that should low numbers of unculturable bacteria be present, they would not be detected with any of the currently available means.

  3. Germ cell cluster organization and oogenesis in the tardigrade Dactylobiotus parthenogeneticus Bertolani, 1982 (Eutardigrada, Murrayidae).

    PubMed

    Poprawa, Izabela; Hyra, Marta; Rost-Roszkowska, Magdalena Maria

    2015-07-01

    Germ cell cluster organization and the process of oogenesis in Dactylobiotus parthenogeneticus have been described using transmission electron microscopy and light microscopy. The reproductive system of D. parthenogeneticus is composed of a single, sac-like, meroistic ovary and a single oviduct that opens into the cloaca. Two zones can be distinguished in the ovary: a small germarium that is filled with oogonia and a vitellarium that is filled with germ cell clusters. The germ cell cluster, which has the form of a modified rosette, consists of eight cells that are interconnected by stable cytoplasmic bridges. The cell that has the highest number of stable cytoplasmic bridges (four bridges) finally develops into the oocyte, while the remaining cells become trophocytes. Vitellogenesis of a mixed type occurs in D. parthenogeneticus. One part of the yolk material is produced inside the oocyte (autosynthesis), while the second part is synthesized in the trophocytes and transported to the oocyte through the cytoplasmic bridges. The eggs are covered with two envelopes: a thin vitelline envelope and a three-layered chorion. The surface of the chorion forms small conical processes, the shape of which is characteristic for the species that was examined. In our paper, we present the first report on the rosette type of germ cell clusters in Parachela.

  4. Tocopherols and tocotrienols in barley oil prepared from germ and other fractions from scarification and sieving of hulless barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two cultivars of hulless barley (Doyce and Merlin), were scarified to abrade the outer layers of the kernels (germ, pericarp, and aleurone). The resulting scarification fines fractions were then separated into four particle size subfractions using sieves. Each of the size subfractions was then extr...

  5. Dnd knockout ablates germ cells and demonstrates germ cell independent sex differentiation in Atlantic salmon

    PubMed Central

    Wargelius, Anna; Leininger, Sven; Skaftnesmo, Kai Ove; Kleppe, Lene; Andersson, Eva; Taranger, Geir Lasse; Schulz, Rüdiger W; Edvardsen, Rolf B

    2016-01-01

    Introgression of farmed salmon escapees into wild stocks is a major threat to the genetic integrity of wild populations. Using germ cell-free fish in aquaculture may mitigate this problem. Our study investigated whether it is possible to produce germ cell-free salmon in F0 by using CRISPR-Cas9 to knock out dnd, a factor required for germ cell survival in vertebrates. To avoid studying mosaic animals, sgRNA targeting alb was simultaneously used as a visual tracer since the phenotype of alb KO is complete loss of pigmentation. Induced mutations for the tracer (alb) and the target (dnd) genes were highly correlated and produced germ cell-less fish lacking pigmentation, underlining the suitability of alb KO to serve as tracer for targeted double allelic mutations in F0 animals in species with prohibitively long generation times. This is also the first report describing dnd knockout in any fish species. Analyzing gene expression and histology of dnd KO fish revealed that sex differentiation of the somatic compartment does not depend on the presence of germ cells. However, the organization of the ovarian somatic compartment seems compromised in mutant fish. PMID:26888627

  6. Combination Chemotherapy in Treating Young Patients With Recurrent or Resistant Malignant Germ Cell Tumors

    ClinicalTrials.gov

    2016-04-12

    Childhood Extracranial Germ Cell Tumor; Childhood Extragonadal Germ Cell Tumor; Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Ovarian Choriocarcinoma; Ovarian Embryonal Carcinoma; Ovarian Yolk Sac Tumor; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Testicular Choriocarcinoma; Testicular Choriocarcinoma and Embryonal Carcinoma; Testicular Choriocarcinoma and Yolk Sac Tumor; Testicular Embryonal Carcinoma; Testicular Embryonal Carcinoma and Yolk Sac Tumor; Testicular Yolk Sac Tumor

  7. Understanding Mammalian Germ Line Development with In Vitro Models.

    PubMed

    Martínez-Arroyo, Ana M; Míguez-Forján, Jose M; Remohí, Jose; Pellicer, Antonio; Medrano, Jose V

    2015-09-15

    Germ line development is crucial in organisms with sexual reproduction to complete their life cycle. In mammals, knowledge about germ line development is based mainly on the mouse model, in which genetic and epigenetic events are well described. However, little is known about how germ line development is orchestrated in humans, especially in the earliest stages. New findings derived from human in vitro models to obtain germ cells can shed light on these questions. This comprehensive review summarizes the current knowledge about mammalian germ line development, emphasizing the state of the art obtained from in vitro models for germ cell-like cell derivation. Current knowledge of the pluripotency cycle and germ cell specification has allowed different in vitro strategies to obtain germ cells with proven functionality in mouse models. Several reports during the last 10 years show that in vitro germ cell derivation with proven functionality to generate a healthy offspring is possible in mice. However, differences in the embryo development and pluripotency potential between human and mouse make it difficult to extrapolate these results. Further efforts on both human and mouse in vitro models to obtain germ cells from pluripotent stem cells may help to elucidate how human physiological events take place; therefore, therapeutic strategies can also be considered.

  8. Sex Specification and Heterogeneity of Primordial Germ Cells in Mice

    PubMed Central

    Sakashita, Akihiko; Kawabata, Yukiko; Jincho, Yuko; Tajima, Shiun; Kumamoto, Soichiro; Kobayashi, Hisato; Matsui, Yasuhisa; Kono, Tomohiro

    2015-01-01

    In mice, primordial germ cells migrate into the genital ridges by embryonic day 13.5 (E13.5), where they are then subjected to a sex-specific fate with female and male primordial germ cells undergoing mitotic arrest and meiosis, respectively. However, the sex-specific basis of primordial germ cell differentiation is poorly understood. The aim of this study was to investigate the sex-specific features of mouse primordial germ cells. We performed RNA-sequencing (seq) of E13.5 female and male mouse primordial germ cells using next-generation sequencing. We identified 651 and 428 differentially expressed transcripts (>2-fold, P < 0.05) in female and male primordial germ cells, respectively. Of these, many transcription factors were identified. Gene ontology and network analysis revealed differing functions of the identified female- and male-specific genes that were associated with primordial germ cell acquisition of sex-specific properties required for differentiation into germ cells. Furthermore, DNA methylation and ChIP-seq analysis of histone modifications showed that hypomethylated gene promoter regions were bound with H3K4me3 and H3K27me3. Our global transcriptome data showed that in mice, primordial germ cells are decisively assigned to a sex-specific differentiation program by E13.5, which is necessary for the development of vital germ cells. PMID:26700643

  9. Synchronous chaos and broad band gamma rhythm in a minimal multi-layer model of primary visual cortex.

    PubMed

    Battaglia, Demian; Hansel, David

    2011-10-01

    Visually induced neuronal activity in V1 displays a marked gamma-band component which is modulated by stimulus properties. It has been argued that synchronized oscillations contribute to these gamma-band activity. However, analysis of Local Field Potentials (LFPs) across different experiments reveals considerable diversity in the degree of oscillatory behavior of this induced activity. Contrast-dependent power enhancements can indeed occur over a broad band in the gamma frequency range and spectral peaks may not arise at all. Furthermore, even when oscillations are observed, they undergo temporal decorrelation over very few cycles. This is not easily accounted for in previous network modeling of gamma oscillations. We argue here that interactions between cortical layers can be responsible for this fast decorrelation. We study a model of a V1 hypercolumn, embedding a simplified description of the multi-layered structure of the cortex. When the stimulus contrast is low, the induced activity is only weakly synchronous and the network resonates transiently without developing collective oscillations. When the contrast is high, on the other hand, the induced activity undergoes synchronous oscillations with an irregular spatiotemporal structure expressing a synchronous chaotic state. As a consequence the population activity undergoes fast temporal decorrelation, with concomitant rapid damping of the oscillations in LFPs autocorrelograms and peak broadening in LFPs power spectra. We show that the strength of the inter-layer coupling crucially affects this spatiotemporal structure. We predict that layer VI inactivation should induce global changes in the spectral properties of induced LFPs, reflecting their slower temporal decorrelation in the absence of inter-layer feedback. Finally, we argue that the mechanism underlying the emergence of synchronous chaos in our model is in fact very general. It stems from the fact that gamma oscillations induced by local delayed

  10. Standard-Dose Combination Chemotherapy or High-Dose Combination Chemotherapy and Stem Cell Transplant in Treating Patients With Relapsed or Refractory Germ Cell Tumors

    ClinicalTrials.gov

    2016-07-26

    Germ Cell Tumor; Teratoma; Choriocarcinoma; Germinoma; Mixed Germ Cell Tumor; Yolk Sac Tumor; Childhood Teratoma; Malignant Germ Cell Neoplasm; Extragonadal Seminoma; Non-seminomatous Germ Cell Tumor; Seminoma

  11. Principal component and cluster analysis of layer V pyramidal cells in visual and non-visual cortical areas projecting to the primary visual cortex of the mouse.

    PubMed

    Laramée, M E; Rockland, K S; Prince, S; Bronchti, G; Boire, D

    2013-03-01

    The long-distance corticocortical connections between visual and nonvisual sensory areas that arise from pyramidal neurons located within layer V can be considered as a subpopulation of feedback connections. The purpose of the present study is to determine if layer V pyramidal neurons from visual and nonvisual sensory cortical areas that project onto the visual cortex (V1) constitute a homogeneous population of cells. Additionally, we ask whether dendritic arborization relates to the target, the sensory modality, the hierarchical level, or laterality of the source cortical area. Complete 3D reconstructions of dendritic arbors of retrogradely labeled layer V pyramidal neurons were performed for neurons of the primary auditory (A1) and somatosensory (S1) cortices and from the lateral (V2L) and medial (V2M) parts of the secondary visual cortices of both hemispheres. The morphological parameters extracted from these reconstructions were subjected to principal component analysis (PCA) and cluster analysis. The PCA showed that neurons are distributed within a continuous range of morphologies and do not form discrete groups. Nevertheless, the cluster analysis defines neuronal groups that share similar features. Each cortical area includes neurons belonging to several clusters. We suggest that layer V feedback connections within a single cortical area comprise several cell types. PMID:22426333

  12. Metformin Hydrochloride, Carboplatin, and Paclitaxel in Treating Patients With Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

    ClinicalTrials.gov

    2015-05-01

    Ovarian Papillary Serous Carcinoma; Ovarian Serous Cystadenocarcinoma; Recurrent Fallopian Tube Cancer; Recurrent Ovarian Epithelial Cancer; Recurrent Ovarian Germ Cell Tumor; Recurrent Primary Peritoneal Cavity Cancer

  13. Hepatocyte growth factor is involved in the morphogenesis of tooth germ in murine molars.

    PubMed

    Tabata, M J; Kim, K; Liu, J G; Yamashita, K; Matsumura, T; Kato, J; Iwamoto, M; Wakisaka, S; Matsumoto, K; Nakamura, T; Kumegawa, M; Kurisu, K

    1996-04-01

    The patterns of gene expression for hepatocyte growth factor (HGF) and its receptor, c-Met, were revealed in the tooth germ of rat mandibular molars using RT-PCR. In situ hybridization demonstrated that the HGF gene was expressed only in the cells of the dental papilla of the tooth germ in vivo. The characteristic temporospatial distribution of HGF and c-Met during germ development was revealed using immunohistochemical studies in vivo. In order to demonstrate the functional role played by HGF in tooth development, HGF translation arrest by antisense phosphorothioate oligodeoxynucleotide (ODN) was carried out in vitro. In the control experiment, explants of tooth germs from embryonic 14 day mice were cultured in a modification of Trowell's system under serum-free and chemically defined conditions for two weeks. Other explants were cultured with 15mer antisense or sense ODN targeted to the HGF mRNA. Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hand, antisense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layer of dentin and dental papilla, appearing 'inside-out' compared to the control and sense-treated explants, although the cytodifferentiation of ameloblasts and odontoblasts was not inhibited. The explants treated with recombinant human HGF combined with antisense ODN showed normal development, indicating that exogenous HGF rescued the explants from the abnormal structure caused by antisense ODN. The findings of a BrdU incorporation experiment suggested that the imbalance between the proliferation activity of the inner enamel epithelium and that of the dental papilla caused by HGF translation arrest results in the abnormal structure of the tooth germ. These results indicate that HGF is involved in the morphogenesis of the murine molar. PMID:8620851

  14. Expression of Genes Related to Germ Cell Lineage and Pluripotency in Single Cells and Colonies of Human Adult Germ Stem Cells

    PubMed Central

    Conrad, Sabine; Azizi, Hossein; Hatami, Maryam; Kubista, Mikael; Bonin, Michael; Hennenlotter, Jörg; Sievert, Karl-Dietrich; Skutella, Thomas

    2016-01-01

    The aim of this study was to elucidate the molecular status of single human adult germ stem cells (haGSCs) and haGSC colonies, which spontaneously developed from the CD49f MACS and matrix- (collagen−/laminin+ binding-) selected fraction of enriched spermatogonia. Single-cell transcriptional profiling by Fluidigm BioMark system of a long-term cultured haGSCs cluster in comparison to human embryonic stem cells (hESCs) and human fibroblasts (hFibs) revealed that haGSCs showed a characteristic germ- and pluripotency-associated gene expression profile with some similarities to hESCs and with a significant distinction from somatic hFibs. Genome-wide comparisons with microarray analysis confirmed that different haGSC colonies exhibited gene expression heterogeneity with more or less pluripotency. The results of this study confirm that haGSCs are adult stem cells with a specific molecular gene expression profile in vitro, related but not identical to true pluripotent stem cells. Under ES-cell conditions haGSC colonies could be selected and maintained in a partial pluripotent state at the molecular level, which may be related to their cell plasticity and potential to differentiate into cells of all germ layers. PMID:26649052

  15. Germ line development: lessons learned from pluripotent stem cells.

    PubMed

    Martínez-Arroyo, Ana M; Medrano, Jose V; Remohí, José; Simón, Carlos

    2014-10-01

    Current knowledge about mammalian germ line development is mainly based on the mouse model and little is known about how this fundamental process occurs in humans. This review summarizes our current knowledge of genetic and epigenetic germ line development in mammals, mainly focusing on primordial germ cell (PGC) specification events, comparing the differences between mouse and human models. We also emphasize the knowledge derived from the most successful strategies used to generate germ cell-like cells in vitro in both models and major obstacles to obtaining bona fide in vitro-derived gametes are considered. PMID:25461452

  16. Germ-line enhancement of humans and non-humans.

    PubMed

    Loftis, J Robert

    2005-03-01

    The current difference in attitude toward germ-line enhancement in humans and nonhumans is unjustified. Society should be more cautious in modifying the genes of nonhumans and more bold in thinking about modifying our own genome. I identify four classes of arguments pertaining to germ-line enhancement: safety arguments, justice arguments, trust arguments, and naturalness arguments. The first three types are compelling, but do not distinguish between human and nonhuman cases. The final class of argument would justify a distinction between human and nonhuman germ-line enhancement; however, this type of argument fails and, therefore, the discrepancy in attitude toward human and nonhuman germ-line enhancement is unjustified.

  17. Overview of the Graphical User Interface for the GERM Code (GCR Event-Based Risk Model

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee; Cucinotta, Francis A.

    2010-01-01

    The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERM code calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERM code also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERM code accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERM code for application to thick target experiments. The GERM code provides scientists participating in NSRL experiments with the data needed for the interpretation of their

  18. Distribution of carotenoids in endosperm, germ, and aleurone fractions of cereal grain kernels.

    PubMed

    Ndolo, Victoria U; Beta, Trust

    2013-08-15

    To compare the distribution of carotenoids across the grain, non-corn and corn cereals were hand dissected into endosperm, germ and aleurone fractions. Total carotenoid content (TCC) and carotenoid composition were analysed using spectrophotometry and HPLC. Cereal carotenoid composition was similar; however, concentrations varied significantly (p<0.05). Endosperm fractions had TCC ranging from 0.88 to 2.27 and 14.17 to 31.35 mg/kg in non-corn cereals and corn, respectively. TCC, lutein and zeaxanthin in germ fractions were higher in non-corn cereals than in corn. Lutein and zeaxanthin contents were lower in non-corn cereal endosperms. The aleurone layer had zeaxanthin levels 2- to 5-fold higher than lutein among the cereals. Positive significant correlations (p<0.05) were found between TCC, carotenoids analysed by HPLC and DPPH results. This study is the first to report on carotenoid composition of the aleurone layer. Our findings suggest that the aleurone of wheat, oat, corn and germ of barley have significantly enhanced carotenoid levels.

  19. Basal Dendrites of Layer-III Pyramidal Neurons do not Scale with Changes in Cortical Magnification Factor in Macaque Primary Visual Cortex

    PubMed Central

    Oga, Tomofumi; Okamoto, Tsuguhisa; Fujita, Ichiro

    2016-01-01

    Neurons in the mammalian primary visual cortex (V1) are systematically arranged across the cortical surface according to the location of their receptive fields (RFs), forming a visuotopic (or retinotopic) map. Within this map, the foveal visual field is represented by a large cortical surface area, with increasingly peripheral visual fields gradually occupying smaller cortical areas. Although cellular organization in the retina, such as the spatial distribution of ganglion cells, can partially account for the eccentricity-dependent differences in the size of cortical representation, whether morphological differences exist across V1 neurons representing different eccentricities is unclear. In particular, morphological differences in dendritic field diameter might contribute to the magnified representation of the central visual field. Here, we addressed this question by measuring the basal dendritic arbors of pyramidal neurons of layer-IIIC and adjoining layer III sublayers (in the Hassler’s nomenclature) in macaque V1. We labeled layer-III pyramidal neurons at various retinotopic positions in V1 by injecting lightly fixed brain tissue with intracellular dye, and then compared dendritic morphology across regions in the retinotopic map representing 0–20° of eccentricity. The dendritic field area, total dendritic length, number of principal dendrites, branching complexity, spine density and total number of spines were all consistent across different retinotopic regions of V1. These results indicate that dendrites in layer-III pyramidal neurons are relatively homogeneous according to these morphometric parameters irrespective of their locations in this portion of the retinotopic map. The homogeneity of dendritic morphology in these neurons suggests that the emphasis of central visual field representation is not attributable to changes in the basal dendritic arbors of pyramidal neurons in layer III, but is likely the result of successive processes earlier in the

  20. Pathology of testicular germ cell tumors.

    PubMed

    Brodsky, G L

    1991-12-01

    The pathology report on a testicular germ cell tumor should include the following information: Tumor type: The histologic type of tumor present. If the tumor is of mixed type, the components should be listed, in order of relative abundance. The pathologist may endeavor to give a numeric estimate of the percentages of each element. Staging information: The size of the tumor should be listed. Local spread--into rete testis, tunica albuginea, epididymis, and spermatic cord--should be listed. If the cord is involved, possible involvement of its surgical resection margin should be assessed. Vascular/lymphatic invasion should be assessed for its presence or absence. Status of the remainder of the testis: Evidence of cryptorchidism or other dysgenetic features should be mentioned. Such features may imply a greater risk for the development of a contralateral tumor. Also, the presence of normal spermatogenesis elsewhere in the uninvolved testis should be reported. This finding may suggest a relatively decreased risk for contralateral tumor development and is a likely indicator of fertility should the patient consider sperm banking prior to retroperitoneal surgery and chemotherapy. The finding of mature sperm in the epididymis is an easy way to confirm spermatogenesis in the testis. Incidental findings: Lipomas or hydroceles of the cord, adrenal rests, and adnexal cysts may be found. The pathologist plays a crucial role in the diagnosis of germ cell tumors. In addition to elucidating tumor type, the pathologist is relied upon for precise local staging and for the classification of metastases, all of which have important implications in determining optimal therapy. As the clinical management of germ cell tumors evolves, the pathologist will continue to play a role in defining those features that have a bearing on patient outcome.

  1. Topology of the germ plasm and development of primordial germ cells in inverted amphibian eggs

    NASA Technical Reports Server (NTRS)

    Wakahara, M.; Neff, A. W.; Malacinski, G. M.

    1984-01-01

    Inverted Xenopus eggs have reduced numbers of primordial germ cells (PGCs). The extent of the reduction varies from spawning to spawning. Histologic examination revealed that PGC counts were lowest in inverted eggs which displayed the greatest amount of shift in the vegetal mass of large yolk platelets, although the germ plasm itself always remained localized in the egg's original vegetal hemisphere. Even at blastulation the germ plasm continued to be localized in the egg's original vegetal hemisphere. In many cases, however, it was confined to the periphery of the embryo, which probably accounts for the reduced PGC number in some tadpoles. In other cases it may have been dispersed and therefore not detectable in histologic analyses. Although the altered site of involution in inverted embryos did not influence PGC development, subsequent cell movement patterns apparently did. Those embryos which displayed the largest degree of pattern reversal at the tail-bud stage also exhibited the most extreme reduction in PGC numbers. A brief cold shock (4 degrees C, 10 min) prior to first cleavage leads to a further reduction in PGC numbers in inverted embryos, probably as a result of the displacement of the germ plasm away from its original vegetal pole location.

  2. Late Relapse of Testicular Germ Cell Tumors.

    PubMed

    O'Shaughnessy, Matthew J; Feldman, Darren R; Carver, Brett S; Sheinfeld, Joel

    2015-08-01

    Germ cell tumors of the testis have an overall survival rate greater than 90% as a result of a successful multidisciplinary approach to management. Late relapse affects a subset of patients however, and tends to be chemorefractory and the overall prognosis is poor. Surgery is the mainstay in management of late relapse but salvage chemotherapy can be successful. In this review, the clinical presentation and detection of late relapse, clinical outcomes, and predictors of survival in late relapse and the importance of a multidisciplinary treatment approach for successful management of late relapse are discussed. PMID:26216823

  3. Zebrafish germ cells: motility and guided migration.

    PubMed

    Paksa, Azadeh; Raz, Erez

    2015-10-01

    In the course of embryonic development, the process of cell migration is critical for establishment of the embryonic body plan, for morphogenesis and for organ function. Investigating the molecular mechanisms underlying cell migration is thus crucial for understanding developmental processes and clinical conditions resulting from abnormal cell migration such as cancer metastasis. The long-range migration of primordial germ cells toward the region at which the gonad develops occurs in embryos of various species and thus constitutes a useful in vivo model for single-cell migration. Recent studies employing zebrafish embryos have greatly contributed to the understanding of the mechanisms facilitating the migration of these cells en route to their target.

  4. Human primordial germ cell-derived progenitors give rise to neurons and glia in vivo

    SciTech Connect

    Teng, Yincheng; Chen, Bin; Tao, Minfang

    2009-12-18

    We derived a cell population from cultured human primordial germ cells from early human embryos. The derivates, termed embryoid body-derived (EBD) cells, displayed an extensive capacity for proliferation and expressed a panel of markers in all three germ layers. Interestingly, EBD cells were also positive for markers of neural stem/progenitor cells, such as nestin and glial fibrillary acidic protein. When these cells were transplanted into the brain cavities of fetal sheep and postnatal NOD-SCID mice or nerve-degenerated tibialis anterior muscles, they readily gave rise to neurons or glial cells. To our knowledge, our data are the first to demonstrate that EBD cells can undergo further neurogenesis under suitable environments in vivo. Hence, with the abilities of extensive expansion, self-renewal, and differentiation, EBD cells may provide a useful donor source for neural stem/progenitor cells to be used in cell-replacement therapies for diseases of the nervous system.

  5. Germ cell differentiation and proliferation in the developing testis of the South American plains viscacha, Lagostomus maximus (Mammalia, Rodentia).

    PubMed

    Gonzalez, C R; Muscarsel Isla, M L; Fraunhoffer, N A; Leopardo, N P; Vitullo, A D

    2012-08-01

    Cell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH.

  6. Retroperitoneal Leiomyosarcoma Associated with an Elevated β-HCG Serum Level Mimicking Extragonadal Germ Cell Tumor

    PubMed Central

    Gaertner, Hans-Juergen; Manseck, Andreas; Oehlschlaeger, Sven; Wirth, Manfred P.

    2000-01-01

    Patient. A 65-year-old man was admitted with a large primary retroperitoneal tumor and an increased β-human chorionic gonadotropin (β-HCG) serum level. A germ cell tumor was suspected; however, a computed tomography-guided biopsy failed to enable tumor classification. After two courses of chemotherapy, the β-HCG serum level had returned to the normal level and a diagnostic laparotomy with incisional biopsy was performed. The immunohistochemical examination of the specimen identified the tumor as a retroperitoneal pleomorphic leiomyosarcoma. Discussion. Tumor markers play only a marginal role in the work-up of patients with soft tissue sarcomas. In men with suspected retroperitoneal sarcomas, however, the determination of germ cell tumor markers occasionally enables a preoperative distinguishing of primary retroperitoneal germ cell tumors with considerable consequences for management. In this setting, a retroperitoneal tumor associated with a moderately elevated β-HCG is a diagnostic dilemma, and surgeons should be aware of the pitfall of a β-HCG-producing leiomyosarcoma in the differential diagnosis. PMID:18521299

  7. Patchy distributions of myelin and vesicular glutamate transporter 2 align with cytochrome oxidase blobs and interblobs in the superficial layers of the primary visual cortex

    PubMed Central

    Rockoff, Emily C; Balaram, Pooja; Kaas, Jon H

    2015-01-01

    Blobs are a modular component of the primary visual cortex (area 17) of all primates, but not of other mammals closely related to primates. They are characterized as an even distribution of patches, puffs, or blobs of dense cytochrome oxidase (CO) expression in layer III of area 17, and are now known to differ from surrounding, nonblob cortex in thalamic, intrinsic, and extrastriate connections. Previous studies have also recognized a blob-like pattern of myelin-dense patches in layer III of area 17 of primates, and more recently the vesicular glutamate transporter (VGLUT)-2 isoform of the VGLUT family has been found to selectively distribute to layer III patches in a similar blob-like pattern. Here, we sought to determine if the blob-like patterns all identify the same modular structures in area 17 of primates by staining alternate brain sections cut parallel to the surface of area 17 of a prosimian primate (Otolemur garnettii) for CO, myelin, and VGLUT2. By aligning the sections from the three preparations, we provide clear evidence that the three preparations all identify the same modular blob structures. The results provide a further understanding of the functional nature of the blobs by demonstrating that their higher level of CO activity is related to thalamic inputs from the lateral geniculate nucleus that use VGLUT2 as their main glutamate transporter, and via myelinated axons. PMID:26097384

  8. Microsurgical removal of epidermal and cortical cells: evidence that the gravitropic signal moves through the outer cell layers in primary roots of maize

    NASA Technical Reports Server (NTRS)

    Yang, R. L.; Evans, M. L.; Moore, R.

    1990-01-01

    There is general agreement that during root gravitropism some sort of growth-modifying signal moves from the cap to the elongation zone and that this signal ultimately induces the curvature that leads to reorientation of the root. However, there is disagreement regarding both the nature of the signal and the pathway of its movement from the root cap to the elongation zone. We examined the pathway of movement by testing gravitropism in primary roots of maize (Zea mays L.) from which narrow (0.5 mm) rings of epidermal and cortical tissue were surgically removed from various positions within the elongation zone. When roots were girdled in the apical part of the elongation zone gravitropic curvature occurred apical to the girdle but not basal to the girdle. Filling the girdle with agar allowed curvature basal to the girdle to occur. Shallow girdles, in which only two or three cell layers (epidermis plus one or two cortical cell layers) were removed, prevented or greatly delayed gravitropic curvature basal to the girdle. The results indicate that the gravitropic signal moves basipetally through the outermost cell layers, perhaps through the epidermis itself.

  9. August Weismann on germ-plasm variation.

    PubMed

    Winther, R G

    2001-01-01

    August Weismann is famous for having argued against the inheritance of acquired characters. However, an analysis of his work indicates that Weismann always held that changes in external conditions, acting during development, were the necessary causes of variation in the hereditary material. For much of his career he held that acquired germ-plasm variation was inherited. An irony, which is in tension with much of the standard twentieth-century history of biology, thus exists - Weismann was not a Weismannian. I distinguish three claims regarding the germ-plasm: (1) its continuity, (2) its morphological sequestration, and (3) its variational sequestration. With respect to changes in Weismann's views on the cause of variation, I divide his career into four stages. For each stage I analyze his beliefs on the relative importance of changes in external conditions and sexual reproduction as causes of variation in the hereditary material. Weissmann believed, and Weismannism denies, that variation, heredity, and development were deeply intertwined processes. This article is part of a larger project comparing commitments regarding variation during the latter half of the nineteenth century. PMID:11859887

  10. The Formation of Germ Cell for Organizational Learning

    ERIC Educational Resources Information Center

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  11. Is Tobacco Smoke a Germ-Cell Mutagen?

    EPA Science Inventory

    Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

  12. Tooth Germ-Like Construct Transplantation for Whole-Tooth Regeneration: An In Vivo Study in the Miniature Pig.

    PubMed

    Yang, Kai-Chiang; Kitamura, Yutaka; Wu, Chang-Chin; Chang, Hao-Hueng; Ling, Thai-Yen; Kuo, Tzong-Fu

    2016-04-01

    The purpose of this study was to demonstrate the feasibility of whole-tooth regeneration using a tooth germ-like construct. Dental pulp from upper incisors, canines, premolars, and molars were extracted from sexually mature miniature pigs. Pulp tissues were cultured and expanded in vitro to obtain dental pulp stem cells (DPSCs), and cells were differentiated into odontoblasts and osteoblasts. Epithelial cells were isolated from gingival epithelium. The epithelial cells, odontoblasts, and osteoblasts were seeded onto the surface, upper, and lower layers, respectively, of a bioactive scaffold. The lower first and second molar tooth germs were removed bilaterally and the layered cell/scaffold constructs were transplanted to the mandibular alveolar socket of a pig. At 13.5 months postimplantation, seven of eight pigs developed two teeth with crown, root, and pulp structures. Enamel-like tissues, dentin, cementum, odontoblasts, and periodontal tissues were found upon histological inspection. The regenerated tooth expressed dentin matrix protein-1 and osteopontin. All pigs had regenerated molar teeth regardless of the original tooth used to procure the DPSCs. Pigs that had tooth germs removed or who received empty scaffolds did not develop teeth. Although periodontal ligaments were generated, ankylosis was found in some animals. This study revealed that implantation of a tooth germ-like structure generated a complete tooth with a high success rate. The implant location may influence the morphology of the regenerated tooth.

  13. Origin and development of the germ line in sea stars.

    PubMed

    Wessel, Gary M; Fresques, Tara; Kiyomoto, Masato; Yajima, Mamiko; Zazueta, Vanesa

    2014-05-01

    This review summarizes and integrates our current understanding of how sea stars make gametes. Although little is known of the mechanism of germ line formation in these animals, recent results point to specific cells and to cohorts of molecules in the embryos and larvae that may lay the ground work for future research efforts. A coelomic outpocketing forms in the posterior of the gut in larvae, referred to as the posterior enterocoel (PE), that when removed, significantly reduces the number of germ cell later in larval growth. This same PE structure also selectively accumulates several germ-line associated factors-vasa, nanos, piwi-and excludes factors involved in somatic cell fate. Since its formation is relatively late in development, these germ cells may form by inductive mechanisms. When integrated into the morphological observations of germ cells and gonad development in larvae, juveniles, and adults, the field of germ line determination appears to have a good model system to study inductive germ line determination to complement the recent work on the molecular mechanisms in mice. We hope this review will also guide investigators interested in germ line determination and regulation of the germ line into how these animals can help in this research field. The review is not intended to be comprehensive-sea star reproduction has been studied for over 100 years and many reviews are comprehensive in their coverage of, for example, seasonal growth of the gonads in response to light, nutrient, and temperature. Rather the intent of this review is to help the reader focus on new experimental results attached to the historical underpinnings of how the germ cell functions in sea stars with particular emphasis to clarify the important areas of priority for future research.

  14. The treatment of cranial germ cell tumours.

    PubMed

    Brandes, A A; Pasetto, L M; Monfardini, S

    2000-08-01

    Germ cell tumours of the central nervous system (CNS) include many subtypes whose response to treatment varies, even though the symptoms and radiological appearances are similar. Five-year survival rates are 96% for germinomas, 100% for mature teratomas, 67% for immature teratomas and 69% for immature teratomas mixed with germinomas; for beta-HCG secreting germinomas the rate is only 38%. Patients with choriocarcinoma, embryonal carcinoma, or yolk sac tumour have the lowest survival rates; patients with germinoma or mature teratoma have longer survival rates. Although a wider resection is associated with a higher rate of survival for patients with non-germinomatous germ cell (NGGC) tumours, to date an aggressive surgical approach has been advocated only for pineal region tumours, but not for hypothalamic/neurohypophyseal tumours. Beside the delayed injury induced by radiotherapy, the late injury induced by chemotherapy is becoming increasingly evident. Cisplatin is considered an indispensable drug, but it may cause renal damage, ototoxicity, peripheral neuropathy and sterility, while etoposide is associated with an excess frequency of second neoplasms. Taking into account all of the published literature, the following therapeutic options are suggested: in pure germinoma tumours (GT) radiotherapy alone will usually ensure adequate control of the disease, and the long-term sequelae may be limited by reducing the dose delivered, as was proposed for germ cell testicular tumours, to 30 Gy to limited fields plus 25-30 Gy to the spinal axis if there is disseminated disease. In cases of recurrence, which should be uncommon, patients may be rescued with both radiotherapy and chemotherapy. In NGGC tumours, the prognosis is more unfavourable and there is often dissemination to the spine at diagnosis; however, the tumour's high chemosensitivity suggests neoadjuvant treatment chemotherapy with cisplatin and etoposide for three cycles followed by consolidation radiotherapy with

  15. Alvocidib and Oxaliplatin With or Without Fluorouracil and Leucovorin Calcium in Treating Patients With Relapsed or Refractory Germ Cell Tumors

    ClinicalTrials.gov

    2015-05-11

    Recurrent Extragonadal Seminoma; Recurrent Malignant Extragonadal Germ Cell Tumor; Recurrent Malignant Extragonadal Non-Seminomatous Germ Cell Tumor; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Stage III Testicular Cancer; Stage IV Extragonadal Non-Seminomatous Germ Cell Tumor; Stage IV Extragonadal Seminoma; Stage IV Ovarian Germ Cell Tumor

  16. Changes in Brain Function in Patients With Stage I, Stage II, Stage III, or Stage IV Ovarian, Primary Peritoneal, or Fallopian Tube Cancer Who Are Receiving Chemotherapy

    ClinicalTrials.gov

    2016-10-26

    Cognitive Side Effects of Cancer Therapy; Malignant Ovarian Epithelial Tumor; Ovarian Brenner Tumor; Ovarian Carcinosarcoma; Ovarian Choriocarcinoma; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Dysgerminoma; Ovarian Embryonal Carcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mixed Germ Cell Tumor; Ovarian Mucinous Cystadenocarcinoma; Ovarian Polyembryoma; Ovarian Sarcoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Cystadenocarcinoma; Ovarian Teratoma; Ovarian Yolk Sac Tumor; Stage I Ovarian Cancer; Stage IA Fallopian Tube Cancer; Stage IA Ovarian Cancer; Stage IA Ovarian Germ Cell Tumor; Stage IB Fallopian Tube Cancer; Stage IB Ovarian Cancer; Stage IB Ovarian Germ Cell Tumor; Stage IC Fallopian Tube Cancer; Stage IC Ovarian Cancer; Stage IC Ovarian Germ Cell Tumor; Stage II Ovarian Cancer; Stage IIA Fallopian Tube Cancer; Stage IIA Ovarian Cancer; Stage IIA Ovarian Germ Cell Tumor; Stage IIB Fallopian Tube Cancer; Stage IIB Ovarian Cancer; Stage IIB Ovarian Germ Cell Tumor; Stage IIC Fallopian Tube Cancer; Stage IIC Ovarian Cancer; Stage IIC Ovarian Germ Cell Tumor; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Ovarian Germ Cell Tumor; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Ovarian Germ Cell Tumor; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Ovarian Germ Cell Tumor; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Ovarian Germ Cell Tumor; Stage IV Primary Peritoneal Cancer; Undifferentiated Ovarian Carcinoma

  17. [Outcome of wisdom tooth germ transplantation].

    PubMed

    Strobl, V; Leja, W; Norer, B

    1995-01-01

    In 68 patients, 79 tooth germs of the third molar were transplanted. Out of this group, 43 patients with 50 transplantations under-went a follow-up examination. All surgery was performed by one surgeon. Retrospectively, we tried to establish whether the success of postoperative healing depends on the donor and receiver regions. Crossing the jaw border clearly worsens the prognosis for transplantation. Altogether 9 transplantations turned out to be failures, 7 of which had been transplanted from the upper to the lower jaw. The results of this investigation showed incomplete root development in 34%, the necessity of endodontic treatment in 6% and enlarged periodontal pockets in 8%. Ankylosed teeth were found in 10%; we did not see any root resorptions. PMID:7557789

  18. Air Filters for Germ-free Isolators

    PubMed Central

    Yale, Charles E.; Vivek, Alapakkam R.

    1968-01-01

    A germ-free isolator must have a perfect bacterial filter. This paper describes a new, relatively inexpensive, stainless-steel filter frame, which is easily and quickly assembled and protects the enclosed filter material at all times. Resistance to the flow of air was less than 4 inches of water at an airflow of 30 ft3/min through the filter frame with 204 inches2 of surface area and four, one-half inch thick pieces of fiberglass filter material. This filter performed satisfactorily in our gnotobiotic laboratory and was found to be consistently 100% efficient in removing an aerosol containing Serratia marcescens from an air stream under a variety of operating conditions. Images Fig. 1 Fig. 2 PMID:4881953

  19. Reduced density of geniculocortical terminals in foveal layer 4A in the macaque primary visual cortex: relationship to S-cone density.

    PubMed

    Garcia-Marin, Virginia; Sundiang, Marina; Hawken, Michael J

    2015-09-01

    The S-cone system is closely linked to the perception of blue/yellow. The trichromatic system of Old-World monkeys and humans has relatively few S-cones in the fovea. In this study, we investigated the distribution of putative S-cone afferents in macaques primary visual cortex (V1) which form a characteristic honeycomb arrangement in layer 4A. It was hypothesized that if there were a low number of S-cone opponent projecting neurons in central vision then this would be seen as a reduction in afferents in foveal layer 4A. Recent studies have shown that the vesicular glutamate transporter 2 (VGlut2) is a marker for thalamic afferent terminals in cortex. The distribution of VGlut2-immunoreactive (-ir) terminals was studied in the foveal and perifoveal representation of V1. It was found that there was a substantial reduction in the terminal density in the foveal representation: the density was 5-6 times lower in the foveal V1 than in regions representing perifoveal eccentricities of 1°-2° and beyond. These findings may provide the cortical substrate of foveal tritanopia, the reduced blue perceptual ability for small fields in the center of gaze. PMID:25009312

  20. Reduced Density of Geniculocortical Terminals in Foveal Layer 4A in the Macaque Primary Visual Cortex: Relationship to S-cone Density

    PubMed Central

    Garcia-Marin, Virginia; Sundiang, Marina; Hawken, Michael J

    2014-01-01

    The S-cone system is closely linked to the perception of blue/yellow. The trichromatic system of Old World monkeys and humans has relatively few S-cones in the fovea. In this study we investigated the distribution of putative S-cone afferents in macaques primary visual cortex (V1) which form a characteristic honeycomb arrangement in layer 4A. It was hypothesized that if there were a low number of S-cone opponent projecting neurons in central vision then this would be seen as a reduction in afferents in foveal layer 4A. Recent studies have shown that the vesicular glutamate transporter 2 (VGlut2) is a marker for thalamic afferent terminals in cortex. The distribution of VGlut2-immunoreactive (-ir) terminals was studied in the foveal and perifoveal representation of V1. It was found that there was a substantial reduction in the terminal density in the foveal representation: the density was 5 – 6 times lower in the foveal V1 than in regions representing perifoveal eccentricities of 1–2 degrees and beyond. These findings may provide the cortical substrate of foveal tritanopia, the reduced blue perceptual ability for small fields in the center of gaze. PMID:25009312

  1. Differential response of planktonic primary, bacterial, and dimethylsulfide production rates to static vs. dynamic light exposure in upper mixed-layer summer sea waters

    NASA Astrophysics Data System (ADS)

    Galí, M.; Simó, R.; Pérez, G. L.; Ruiz-González, C.; Sarmento, H.; Royer, S.-J.; Fuentes-Lema, A.; Gasol, J. M.

    2013-12-01

    Microbial plankton experience short-term fluctuations in total solar irradiance and in its spectral composition as they are vertically moved by turbulence in the oceanic upper mixed layer (UML). The fact that the light exposure is not static but dynamic may have important consequences for biogeochemical processes and ocean-atmosphere fluxes. However, most biogeochemical processes other than primary production, like bacterial production or dimethylsulfide (DMS) production, are seldom measured in sunlight and even less often in dynamic light fields. We conducted four experiments in oligotrophic summer stratified Mediterranean waters, where a sample from the UML was incubated in ultraviolet (UV)-transparent bottles at three fixed depths within the UML and on a vertically moving basket across the same depth range. We assessed the response of the phyto- and bacterioplankton community with physiological indicators based on flow cytometry singe-cell measurements, fast repetition rate fluorometry (FRRf), phytoplankton pigment concentrations and particulate light absorption. Dynamic light exposure caused a subtle disruption of the photoinhibition and photoacclimation processes associated with ultraviolet radiation (UVR), which slightly alleviated bacterial photoinhibition but did not favor primary production. Gross DMS production (GPDMS) decreased sharply with depth in parallel to shortwave UVR, and displayed a dose-dependent response that mixing did not significantly disrupt. To our knowledge, we provide the first measurements of GPDMS under in situ UV-inclusive optical conditions.

  2. Differential response of planktonic primary, bacterial, and dimethylsulfide production rates to vertically-moving and static incubations in upper mixed-layer summer sea waters

    NASA Astrophysics Data System (ADS)

    Galí, M.; Simó, R.; Pérez, G. L.; Ruiz-González, C.; Sarmento, H.; Royer, S.-J.; Fuentes-Lema, A.; Gasol, J. M.

    2013-05-01

    Microbial plankton experience fluctuations in total solar irradiance and in its spectral composition as they are vertically moved by turbulence in the oceanic upper mixed layer (UML). The fact that the light exposure is not static but dynamic may have important consequences for biogeochemical processes and ocean-atmosphere fluxes. However, most biogeochemical processes other than primary production, like bacterial production or dimethylsulfide (DMS) production, are seldom measured in sunlight and even less often in dynamic light fields. We conducted four experiments in oligotrophic summer stratified Mediterranean waters, where a sample from the UML was incubated in ultraviolet (UV)-transparent bottles at three fixed depths within the UML and on a vertically-moving basket across the same depth range. We assessed the response of the phyto- and bacterioplankton community with physiological indicators based on flow cytometry singe-cell measurements, Fast Repetition Rate fluorometry (FRRf), phytoplankton pigment concentrations and particulate light absorption. Dynamic light exposure caused a disruption of the photoinhibition and photoacclimation processes associated to ultraviolet radiation (UVR), which slightly alleviated bacterial photoinhibition but did not favor primary production. Gross DMS production (GPDMS) decreased sharply with depth in parallel to shortwave UVR, and displayed a dose-dependent response that mixing did not significantly disrupt. To our knowledge, we provide the first measurements of GPDMS under in situ UV-inclusive optical conditions.

  3. The Effect of Wheat Germ Extract on Premenstrual Syndrome Symptoms

    PubMed Central

    Ataollahi, Maryam; Akbari, Sedigheh Amir Ali; Mojab, Faraz; Alavi Majd, Hamid

    2015-01-01

    Pre-menstrual syndrome is one of the most common disorders in women and impairs work and social relationships. Several treatment modalities have been proposed including herbal medicines. Considering the properties of wheat germ, this study aimed to determine the effects of wheat germ extract on the symptoms of premenstrual syndrome. This triple blind clinical trial was conducted on 84 women working in hospitals affiliated to Hamadan University of Medical Sciences. Subjects completed daily symptom record form for two consecutive months. After definitive diagnosis of premenstrual syndrome, they were randomly divided into two groups of 50 people. Then, for two consecutive months, 400 mg capsules of wheat germ extract or placebo were used three times a day, from day 16 until day 5 of the next menstrual cycle. Wheat germ significantly reduced physical symptoms (63.56%), psychological symptoms (66.30%), and the general score (64.99%). Although the severity of symptoms decreased in both groups, this reduction was more significant in the wheat germ extract group (p < 0.001). On the other hand, physical symptoms decreased only in the wheat germ extract (p < 0.001) and there was no statistically significant difference in the placebo group. No complications were observed in any of the groups. It seems that using wheat germ extract reduces general, psychological and physical symptoms. PMID:25561922

  4. The effect of wheat germ extract on premenstrual syndrome symptoms.

    PubMed

    Ataollahi, Maryam; Akbari, Sedigheh Amir Ali; Mojab, Faraz; Alavi Majd, Hamid

    2015-01-01

    Pre-menstrual syndrome is one of the most common disorders in women and impairs work and social relationships. Several treatment modalities have been proposed including herbal medicines. Considering the properties of wheat germ, this study aimed to determine the effects of wheat germ extract on the symptoms of premenstrual syndrome. This triple blind clinical trial was conducted on 84 women working in hospitals affiliated to Hamadan University of Medical Sciences. Subjects completed daily symptom record form for two consecutive months. After definitive diagnosis of premenstrual syndrome, they were randomly divided into two groups of 50 people. Then, for two consecutive months, 400 mg capsules of wheat germ extract or placebo were used three times a day, from day 16 until day 5 of the next menstrual cycle. Wheat germ significantly reduced physical symptoms (63.56%), psychological symptoms (66.30%), and the general score (64.99%). Although the severity of symptoms decreased in both groups, this reduction was more significant in the wheat germ extract group (p < 0.001). On the other hand, physical symptoms decreased only in the wheat germ extract (p < 0.001) and there was no statistically significant difference in the placebo group. No complications were observed in any of the groups. It seems that using wheat germ extract reduces general, psychological and physical symptoms. PMID:25561922

  5. The making of a germ panic, then and now.

    PubMed Central

    Tomes, N

    2000-01-01

    Over the last 2 decades, a heightened interest in germs has been evident in many aspects of American popular culture, including news coverage, advertisements, and entertainment media. Although clearly a response to the AIDS epidemic and other recent disease outbreaks, current obsessions with germs have some striking parallels with a similar period of intense anxiety about disease germs that occurred between 1900 and 1940. A comparison of these 2 periods of germ "panic" suggests some of the long-term cultural trends that contributed to their making. Both germ panics reflected anxieties about societal incorporation, associated with expanding markets, transportation networks, and mass immigration. They were also shaped by new trends in public health education, journalism, advertising, and entertainment media. In comparison to the first germ panic, the current discourse about the "revenge of the superbugs" is considerably more pessimistic because of increasing worries about the environment, suspicions of governmental authority, and distrust of expert knowledge. Yet, as popular anxieties about infectious disease have increased, public health scientists have been attracting favorable coverage in their role as "medical detectives" on the trail of the "killer germ." PMID:10667179

  6. Hedgehog does not guide migrating Drosophila germ cells

    PubMed Central

    Renault, Andrew D.; Ricardo, Sara; Kunwar, Prabhat S.; Santos, Ana; Starz-Gaiano, Michelle; Stein, Jennifer; Lehmann, Ruth

    2009-01-01

    In many species, the germ cells, precursors of sperm and egg, migrate during embryogenesis. The signals that regulate this migration are thus essential for fertility. In flies, lipid signals have been shown to affect germ cell guidance. In particular, the synthesis of geranylgeranyl pyrophosphate through the 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr) pathway is critical for attracting germ cells to their target tissue. In a genetic analysis of signaling pathways known to affect cell migration of other migratory cells, we failed to find a role for the Hedgehog (Hh) pathway in germ cell migration. However, previous reports had implicated Hh as a germ cell attractant in flies and suggested that Hh signaling is enhanced through the action of the Hmgcr pathway. We therefore repeated several critical experiments and carried out further experiments to test specifically whether Hh is a germ cell attractant in flies. In contrast to previously reported findings and consistent with findings in zebrafish our data do not support the notion that Hh has a direct role in the guidance of migrating germ cells in flies. PMID:19389345

  7. Testicular structure and germ cells morphology in salamanders

    PubMed Central

    Uribe, Mari Carmen; Mejía-Roa, Víctor

    2014-01-01

    Testes of salamanders or urodeles are paired elongated organs that are attached to the dorsal wall of the body by a mesorchium. The testes are composed of one or several lobes. Each lobe is morphologically and functionally a similar testicular unit. The lobes of the testis are joined by cords covered by a single peritoneal epithelium and subjacent connective tissue. The cords contain spermatogonia. Spermatogonia associate with Sertoli cells to form spermatocysts or cysts. The spermatogenic cells in a cyst undergo their development through spermatogenesis synchronously. The distribution of cysts displays the cephalo-caudal gradient in respect to the stage of spermatogenesis. The formation of cysts at cephalic end of the testis causes their migration along the lobules to the caudal end. Consequently, the disposition in cephalo-caudal regions of spermatogenesis can be observed in longitudinal sections of the testis. The germ cells are spermatogonia, diploid cells with mitotic activity; primary and second spermatocytes characterized by meiotic divisions that develop haploid spermatids; during spermiogenesis the spermatids differentiate to spermatozoa. During spermiation the cysts open and spermatozoa leave the testicular lobules. After spermiation occurs the development of Leydig cells into glandular tissue. This glandular tissue regressed at the end of the reproductive cycle. PMID:26413406

  8. DNA replication licensing in somatic and germ cells.

    PubMed

    Eward, Kathryn Leigh; Obermann, Ellen C; Shreeram, S; Loddo, Marco; Fanshawe, Thomas; Williams, Craig; Jung, Hyo-Il; Prevost, A Toby; Blow, J Julian; Stoeber, Kai; Williams, Gareth H

    2004-11-15

    The DNA replication (or origin) licensing system ensures precise duplication of the genome in each cell cycle and is a powerful regulator of cell proliferation in metazoa. Studies in yeast, Drosophila melanogaster and Xenopus laevis have characterised the molecular machinery that constitutes the licensing system, but it remains to be determined how this important evolutionary conserved pathway is regulated in Homo sapiens. We have investigated regulation of the origin licensing factors Cdc6, Cdt1, Mcm2 and Geminin in human somatic and germ cells. Cdc6 and Cdt1 play an essential role in DNA replication initiation by loading the Mcm2-7 complex, which is required for unwinding the DNA helix, onto chromosomal origins. Geminin is a repressor of origin licensing that blocks Mcm2-7 loading onto origins. Our studies demonstrate that Cdc6, Cdt1 and Mcm2 play a central role in coordinating growth during the proliferation-differentiation switch in somatic self-renewing systems and that Cdc6 expression is rate-limiting for acquisition of replication competence in primary oocytes. In striking contrast, we show that proliferation control during male gametogenesis is not linked to Cdc6 or Mcm2, but appears to be coordinated by the negative regulator Geminin with Cdt1 becoming rate-limiting in late prophase. Our data demonstrate a striking sexual dimorphism in the mechanisms repressing origin licensing and preventing untimely DNA synthesis during meiosis I, implicating a pivotal role for Geminin in maintaining integrity of the male germline genome.

  9. Metformin Hydrochloride and Combination Chemotherapy in Treating Patients With Stage III-IV Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

    ClinicalTrials.gov

    2016-05-18

    Brenner Tumor; Malignant Ascites; Malignant Pleural Effusion; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mixed Epithelial Carcinoma; Ovarian Serous Cystadenocarcinoma; Ovarian Undifferentiated Adenocarcinoma; Recurrent Fallopian Tube Cancer; Recurrent Ovarian Epithelial Cancer; Recurrent Ovarian Germ Cell Tumor; Recurrent Primary Peritoneal Cavity Cancer; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Epithelial Cancer; Stage IIIA Ovarian Germ Cell Tumor; Stage IIIA Primary Peritoneal Cavity Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Epithelial Cancer; Stage IIIB Ovarian Germ Cell Tumor; Stage IIIB Primary Peritoneal Cavity Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Epithelial Cancer; Stage IIIC Ovarian Germ Cell Tumor; Stage IIIC Primary Peritoneal Cavity Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Epithelial Cancer; Stage IV Ovarian Germ Cell Tumor; Stage IV Primary Peritoneal Cavity Cancer

  10. Epigenetics: a way to understand the origin and biology of testicular germ cell tumors.

    PubMed

    Okamoto, Keisei

    2012-06-01

    Testicular germ cell tumors are neoplasms carrying two unique features. First, testicular germ cell tumors have a pluripotential nature and show protean histology ranging from that of germ cells to embryonal and differentiated somatic cells. Therefore, testicular germ cell tumors are interesting resources positioned at a crossroad in developmental and neoplastic processes. The second unique feature of testicular germ cell tumors is their exquisite sensitivity to cisplatin-based chemotherapy. This review summarizes recent research progress in the epigenetics of testicular germ cell tumors in an attempt to explain the abovementioned biological and clinical characteristics of testicular germ cell tumors.

  11. Quantification of human telomerase reverse transcriptase mRNA in testicular germ cell tumors by quantitative fluorescence real-time RT-PCR.

    PubMed

    Schrader, Mark; Burger, Angelika M; Müller, Markus; Krause, Hans; Straub, Bernd; Smith, Gilian L; Newlands, Eward S; Miller, Kurt

    2002-01-01

    Telomerase is a ribonucleoprotein enzyme which is endogenously expressed in germ, stem and tumor cells, but absent in benign somatic cells. The two major telomerase components are human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT). It has been shown that hTERT is rate-limiting for telomerase activity and that it plays a central role in human carcinogenesis. Here, we investigated the potential of hTERT and hTR gene expression as diagnostic markers in testicular germ cell tumors (TGCT). hTERT mRNA and hTR expression were quantified in 55 testicular germ cell tumors comprising 36 primary and 19 germ cell tumors from retroperitonal sides by fluorescence real-time RT-PCR using the LightCycler technology. Porphobilinogen deaminase (PBGD) was used as housekeeping gene and to enable relative quantification. For comparison to TGCTs, 38 benign testicular biopsies from patients with fertility disorders were assayed. hTERT expression was detected in all examined undifferentiated TGCTs and in the benign testicular tissue specimens with germ cell content (N(hTERT) 38-127). In contrast, mature teratomas from primary and post-chemotherapy masses, which are characterized by well-differentiated tissue components showed a nearly complete downregulation of hTERT expression (N(hTERT) 2-4, p<0.001). hTR levels however, were high in all tumors and independently of the presence of germ cells also in the benign tissue control group. hTERT mRNA is expressed in all undifferentiated TGCTs but repressed in mature teratomas. This suggests an inverse correlation between the differentiation status of germ cell tumors and hTERT expression. Thus, detection of hTERT expression in tumors histopathologically classified as mature teratomas enables a molecular-diagnostic confirmation and might aid decision making for treatment of patients presenting with this tumor subtype.

  12. Identification of superficial Candida albicans germ tube antigens in a rabbit model of disseminated candidiasis. A proteomic approach.

    PubMed

    Sáez-Rosón, Aranzazu; Sevilla, María-Jesús; Moragues, María-Dolores

    2014-03-01

    The diagnosis of invasive candidiasis remains a clinical challenge. The detection by indirect immunofluorescence of Candida albicans germ-tube-specific antibodies (CAGTA), directed against germ-tube surface antigens, is a useful diagnostic tool that discriminates between colonization and invasion. However, the standardization of this technique is complicated by its reliance on subjective interpretation. In this study, the antigenic recognition pattern of CAGTA throughout experimental invasive candidiasis in a rabbit animal model was determined by means of 2D-PAGE, Western blotting, and tandem mass spectrometry (MS/MS). Seven proteins detected by CAGTA were identified as methionine synthase, inositol-3-phosphate synthase, enolase 1, alcohol dehydrogenase 1,3-phosphoglycerate kinase, 14-3-3 (Bmhl), and Egd2. To our knowledge, this is the first report of antibodies reacting with Bmhl and Egd2 proteins in an animal model of invasive candidiasis. Although all of the antigens were recognized by CAGTA in cell-wall dithiothreitol extracts of both germ tubes and blastospores of C. albicans, immunoelectron microscopy study revealed their differential location, as the antigens were exposed on the germ-tube cell-wall surface but hidden in the inner layers of the blastospore cell wall. These findings will contribute to developing more sensitive diagnostic methods that enable the earlier detection of invasive candidiasis.

  13. Tritium effects on germ cells and fertility

    SciTech Connect

    Dobson, R.L.; Kwan, T.C.; Straume, T.

    1982-11-19

    Primordial oocytes in juvenile mice show acute gamma-ray LD/sub 50/ as low as 6 rad. This provides opportunities for determining dose-response relations at low doses and chronic exposure in the intact animal - conditions of particular interest for hazard evaluation. Examined in this way, /sup 3/HOH in body water is found to kill murine oocytes exponentially with dose, the LD/sub 50/ level for chronic exposure being only 2..mu..Ci/ml (delivering 0.4 rad/day). At very low doses and dose rates, where comparisons between tritium and other radiations are of special significance for radiological protection, the RBE of tritium compared with /sup 60/Co gamma radiation reaches approximately 3. Effects on murine fertility from tritium-induced oocyte loss have been quantified by reproductive capacity measurements. Chronic low-level exposure has been examined also in three primate species - squirrel, rhesus, and bonnet monkeys. In squirrel monkeys the ovarian germ-cell supply is 99% destroyed by the time of birth from prenatal exposure to body-water levels of /sup 3/HOH (administered in maternal drinking water) of only 3 ..mu..Ci/ml, the LD/sub 50/ level being 0.5 ..mu..Ci/ml (giving 0.1 rad/day), one fourth that in mice. Though not completely ruled out, similar high sensitivity of female germ cells has not been found in macaques; and it probably does not occur in man. The exquisite radiosensitivity of primordial oocytes in mice is apparently due to vulnerability of the plasma membrane (or something of similar geometry and location), not DNA. Evidence for this comes from tritium data as well as neutron studies. Tritium administered as /sup 3/HOH, and therefore generally distributed, is much more effective in killing murine oocytes than is tritium administered as /sup 3/H-TdR, localized in the nucleus. This situation in the mouse may have implications for estimating radiation genetic risk in the human female.

  14. Impact of gut microbiota on the fly's germ line.

    PubMed

    Elgart, Michael; Stern, Shay; Salton, Orit; Gnainsky, Yulia; Heifetz, Yael; Soen, Yoav

    2016-01-01

    Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation. PMID:27080728

  15. Stopping the Spread of Germs at Home, Work and School

    MedlinePlus

    ... Newsletters Stopping the Spread of Germs at Home, Work & School Language: English Español Recommend on Facebook ... and answers, and poster materials for schools At Work Flu Prevention at Work Learn more about how ...

  16. Preventing the Flu: Good Health Habits Can Help Stop Germs

    MedlinePlus

    ... Medscape Podcasts Public Service Announcements (PSAs) Virus Images Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... What's this? Submit Button Past Newsletters Preventing the Flu: Good Health Habits Can Help Stop Germs Language: ...

  17. Impact of gut microbiota on the fly's germ line

    PubMed Central

    Elgart, Michael; Stern, Shay; Salton, Orit; Gnainsky, Yulia; Heifetz, Yael; Soen, Yoav

    2016-01-01

    Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation. PMID:27080728

  18. Germ cell transplantation and testis tissue xenografting in mice.

    PubMed

    Tang, Lin; Rodriguez-Sosa, Jose Rafael; Dobrinski, Ina

    2012-01-01

    Germ cell transplantation was developed by Dr. Ralph Brinster and colleagues at the University of Pennsylvania in 1994(1,2). These ground-breaking studies showed that microinjection of germ cells from fertile donor mice into the seminiferous tubules of infertile recipient mice results in donor-derived spermatogenesis and sperm production by the recipient animal(2). The use of donor males carrying the bacterial β-galactosidase gene allowed identification of donor-derived spermatogenesis and transmission of the donor haplotype to the offspring by recipient animals(1). Surprisingly, after transplantation into the lumen of the seminiferous tubules, transplanted germ cells were able to move from the luminal compartment to the basement membrane where spermatogonia are located(3). It is generally accepted that only SSCs are able to colonize the niche and re-establish spermatogenesis in the recipient testis. Therefore, germ cell transplantation provides a functional approach to study the stem cell niche in the testis and to characterize putative spermatogonial stem cells. To date, germ cell transplantation is used to elucidate basic stem cell biology, to produce transgenic animals through genetic manipulation of germ cells prior to transplantation(4,5), to study Sertoli cell-germ cell interaction(6,7), SSC homing and colonization(3,8), as well as SSC self-renewal and differentiation(9,10). Germ cell transplantation is also feasible in large species(11). In these, the main applications are preservation of fertility, dissemination of elite genetics in animal populations, and generation of transgenic animals as the study of spermatogenesis and SSC biology with this technique is logistically more difficult and expensive than in rodents. Transplantation of germ cells from large species into the seminiferous tubules of mice results in colonization of donor cells and spermatogonial expansion, but not in their full differentiation presumably due to incompatibility of the

  19. Evaluation of Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Primary Craniopharyngioma by Fourier-Domain Optical Coherence Tomography

    PubMed Central

    Yang, Liu; Qu, Yuanzhen; Lu, Wen; Liu, Fengjun

    2016-01-01

    Background The aim of this study was to compare the differences in macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) in child and adult patients with primary craniopharyngioma by Fourier-domain optical coherence tomography (FD-OCT) and to evaluate their significance in the diagnosis of primary craniopharyngioma. Material/Methods Ninety-six participants were divided into 3 groups: 32 in the child craniopharyngioma group (CCG) and 32 in the adult craniopharyngioma group (ACG) who were treated in Beijing Tiantan Hospital between November 2013 and October 2014, and 32 in the normal group (NG). All subjects were scanned by FD-OCT to map GCC and pRNFL thicknesses. Spearman correlation coefficient was used to assess the correlation between GCC and pRNFL thickness, and pRNFL thickness and optic nerve head (ONH) parameters, including horizontal cup-disc ratio (HCDR), vertical cup-disc ratio (VCDR), optic disc area (ODA), and cup area (CA), respectively. Results The correlation between GCC and pRNFL thickness in the CCG was slightly stronger compared with the ACG. A significant difference in GCC thickness was observed among the CCG, ACG, and NG. Although the pRNFL thickness in both the CCG and ACG was significantly higher than that in NG, no significant difference in pRNFL thickness was detected between the 2 craniopharyngioma groups. The average, superior, and inferior pRNFL thicknesses were negatively correlated with VCDR in the CCG (in double eyes) and ACG (only in left eyes). Conclusions GCC was more sensitive than pRNFL in detecting optic nerve damage in the eyes of craniopharyngioma patients. A thinner pRNFL was especially correlated with VCDR in child craniopharyngioma patients. PMID:27372909

  20. A Specialized Outer Layer of the Primary Cell Wall Joins Elongating Cotton Fibers into Tissue-Like Bundles1[W][OA

    PubMed Central

    Singh, Bir; Avci, Utku; Eichler Inwood, Sarah E.; Grimson, Mark J.; Landgraf, Jeff; Mohnen, Debra; Sørensen, Iben; Wilkerson, Curtis G.; Willats, William G.T.; Haigler, Candace H.

    2009-01-01

    Cotton (Gossypium hirsutum) provides the world's dominant renewable textile fiber, and cotton fiber is valued as a research model because of its extensive elongation and secondary wall thickening. Previously, it was assumed that fibers elongated as individual cells. In contrast, observation by cryo-field emission-scanning electron microscopy of cotton fibers developing in situ within the boll demonstrated that fibers elongate within tissue-like bundles. These bundles were entrained by twisting fiber tips and consolidated by adhesion of a cotton fiber middle lamella (CFML). The fiber bundles consolidated via the CFML ultimately formed a packet of fiber around each seed, which helps explain how thousands of cotton fibers achieve their great length within a confined space. The cell wall nature of the CFML was characterized using transmission electron microscopy, including polymer epitope labeling. Toward the end of elongation, up-regulation occurred in gene expression and enzyme activities related to cell wall hydrolysis, and targeted breakdown of the CFML restored fiber individuality. At the same time, losses occurred in certain cell wall polymer epitopes (as revealed by comprehensive microarray polymer profiling) and sugars within noncellulosic matrix components (as revealed by gas chromatography-mass spectrometry analysis of derivatized neutral and acidic glycosyl residues). Broadly, these data show that adhesion modulated by an outer layer of the primary wall can coordinate the extensive growth of a large group of cells and illustrate dynamic changes in primary wall structure and composition occurring during the differentiation of one cell type that spends only part of its life as a tissue. PMID:19369592

  1. Use of Stirred Suspension Bioreactors for Male Germ Cell Enrichment.

    PubMed

    Sakib, Sadman; Dores, Camila; Rancourt, Derrick; Dobrinski, Ina

    2016-01-01

    Spermatogenesis is a stem cell based system. Both therapeutic and biomedical research applications of spermatogonial stem cells require a large number of cells. However, there are only few germ line stem cells in the testis, contained in the fraction of undifferentiated spermatogonia. The lack of specific markers makes it difficult to isolate these cells. The long term maintenance and proliferation of nonrodent germ cells in culture has so far been met with limited success, partially due to the lack of highly enriched starting populations. Differential plating, which depends on the differential adhesion properties of testicular somatic and germ cells to tissue culture dishes, has been the method of choice for germ cell enrichment, especially for nonrodent germ cells. However, for large animals, this process becomes labor intensive and increases variability due to the need for extensive handling. Here, we describe the use of stirred suspension bioreactors, as a novel system for enriching undifferentiated germ cells from 1-week-old pigs. This method capitalizes on the adherent properties of somatic cells within a controlled environment, thus promoting the enrichment of progenitor cells with minimal handling and variability.

  2. The chemosensitivity of testicular germ cell tumors.

    PubMed

    Voutsadakis, Ioannis A

    2014-04-01

    Although rare cancers overall, testicular germ cell tumors (TGCTs) are the most common type of cancer in young males below 40 years of age. Both subtypes of TGCTs, i.e., seminomas and non-seminomas, are highly curable and the majority of even metastatic patients may expect to be cured. These high cure rates are not due to the indolent nature of these cancers, but rather to their sensitivity to chemotherapy (and for seminomas to radiotherapy). The delineation of the cause of chemosensitivity at the molecular level is of paramount importance, because it may provide insights into the minority of TGCTs that are chemo-resistant and, thereby, provide opportunities for specific therapeutic interventions aimed at reverting them to chemosensitivity. In addition, delineation of the molecular basis of TGCT chemo-sensitivity may be informative for the cause of chemo-resistance of other more common types of cancer and, thus, may create new therapeutic leads. p53, a frequently mutated tumor suppressor in cancers in general, is not mutated in TGCTs, a fact that has implications for their chemo-sensitivity. Oct4, an embryonic transcription factor, is uniformly expressed in the seminoma and embryonic carcinoma components of non-seminomas, and its interplay with p53 may be important in the chemotherapy response of these tumors. This interplay, together with other features of TGCTs such as the gain of genetic material from the short arm of chromosome 12 and the association with disorders of testicular development, will be discussed in this paper and integrated in a unifying hypothesis that may explain their chemo-sensitivity. PMID:24692098

  3. Identification of novel fusion genes in testicular germ cell tumors

    PubMed Central

    Hoff, Andreas M.; Alagaratnam, Sharmini; Zhao, Sen; Bruun, Jarle; Andrews, Peter W.; Lothe, Ragnhild A.; Skotheim, Rolf I.

    2015-01-01

    Testicular germ cell tumors (TGCT) are the most frequently diagnosed solid tumors in young men ages 15 to 44 years. Embryonal carcinomas (EC) comprise a subset of TGCTs that exhibit pluripotent characteristics similar to embryonic stem (ES) cells, but the genetic drivers underlying malignant transformation of ECs are unknown. To elucidate the abnormal genetic events potentially contributing to TGCT malignancy, such as the existence of fusion genes or aberrant fusion transcript expression, we performed RNA sequencing of EC cell lines and their non-malignant ES cell line counterparts. We identified eight novel fusion transcripts and one gene with alternative promoter usage, ETV6. Four out of nine transcripts were found recurrently expressed in an extended panel of primary TGCTs and additional EC cell lines, but not in normal parenchyma of the testis, implying tumor-specific expression. Two of the recurrent transcripts involved an intrachromosomal fusion between RCC1 and HENMT1 located 80 Mbp apart and an interchromosomal fusion between RCC1 and ABHD12B. RCC1-ABHD12B and the ETV6 transcript variant were found to be preferentially expressed in the more undifferentiated TGCT subtypes. In vitro differentiation of the NTERA2 EC cell line resulted in significantly reduced expression of both fusion transcripts involving RCC1 and the ETV6 transcript variant, indicating that they are markers of pluripotency in a malignant setting. In conclusion, we identified eight novel fusion transcripts that, to our knowledge, are the first fusion genes described in TGCT and may therefore potentially serve as genomic biomarkers of malignant progression. PMID:26659575

  4. A Mechanism of Male Germ Cell Apoptosis Induced by Bisphenol-A and Nonylphenol Involving ADAM17 and p38 MAPK Activation

    PubMed Central

    Moreno, Ricardo D.

    2014-01-01

    Germ cell apoptosis regulation is pivotal in order to maintain proper daily sperm production. Several reports have shown that endocrine disruptors such as Bisphenol-A (BPA) and Nonylphenol (NP) induce germ cell apoptosis along with a decrease in sperm production. Given their ubiquitous distribution in plastic products used by humans it is important to clarify their mechanism of action. TACE/ADAM17 is a widely distributed extracellular metalloprotease and participates in the physiological apoptosis of germ cells during spermatogenesis. The aims of this work were: 1) to determine whether BPA and NP induce ADAM17 activation; and 2) to study whether ADAM17 and/or ADAM10 are involved in germ cell apoptosis induced by BPA and NP in the pubertal rat testis. A single dose of BPA or NP (50 mg/kg) induces germ cell apoptosis in 21-day-old male rats, which was prevented by a pharmacological inhibitor of ADAM17, but not by an inhibitor of ADAM10. In vitro, we showed that BPA and NP, at similar concentrations to those found in human samples, induce the shedding of exogenous and endogenous (TNF-α) ADAM17 substrates in primary rat Sertoli cell cultures and TM4 cell line. In addition, pharmacological inhibitors of metalloproteases and genetic silencing of ADAM17 prevent the shedding induced in vitro by BPA and NP. Finally, we showed that in vivo BPA and NP induced early activation (phosphorylation) of p38 MAPK and translocation of ADAM17 to the cell surface. Interestingly, the inhibition of p38 MAPK prevents germ cell apoptosis and translocation of ADAM17 to the cell surface. These results show for the first time that xenoestrogens can induce activation of ADAM17 at concentrations similar to those found in human samples, suggesting a mechanism by which they could imbalance para/juxtacrine cell-to-cell-communication and induce germ cell apoptosis. PMID:25474107

  5. Indirect Immunofluorescence of Proteins in Oogenic Germ Cells of Caenorhabditis elegans.

    PubMed

    Brenner, John L; Schedl, Tim

    2016-01-01

    Formation of full-grown oocytes requires the control and coordination of a number of processes (e.g., oocyte growth) through multiple stages, where disruption at any one step can result in infertility. Numerous proteins are required for the regulation and execution of the various oogenic processes as well as functioning as maternal products needed for embryogenesis. Immunofluorescence microscopy combined with staining using antibodies against specific proteins, or their posttranslationally modified forms, is a standard approach to determine the temporal and spatial location of gene products that function in oocyte development. The simple linear organization of the germline in the model organism Caenorhabditis elegans allows easy correlation of protein localization and germ cell developmental stage, thus aiding in our understanding of protein function during gametogenesis. Here we outline co-immunofluorescence staining for two major regulators of C. elegans germline development, the translational repressor GLD-1 and activated form of MPK-1 (dpMPK-1) ERK MAP kinase in dissected gonads from adult C. elegans. Worms are first dissected and the extruded gonads are fixed and permeabilized before being bathed in primary antibodies against GLD-1 and dpMPK-1. Secondary antibodies conjugated to fluorophore dyes and that target the IgG domains of the primary antibody reagents are then used to provide a fluorescent signal that corresponds to the position of GLD-1 and dpMPK-1. The outlined procedure is amenable to many other proteins expressed in C. elegans germ cells. PMID:27557570

  6. Amniotic fluid stem cell-based models to study the effects of gene mutations and toxicants on male germ cell formation.

    PubMed

    Gundacker, Claudia; Dolznig, Helmut; Mikula, Mario; Rosner, Margit; Brandau, Oliver; Hengstschläger, Markus

    2012-03-01

    Male infertility is a major public health issue predominantly caused by defects in germ cell development. In the past, studies on the genetic regulation of spermatogenesis as well as on negative environmental impacts have been hampered by the fact that human germ cell development is intractable to direct analysis in vivo. Compared with model organisms including mice, there are fundamental differences in the molecular processes of human germ cell development. Therefore, an in vitro model mimicking human sperm formation would be an extremely valuable research tool. In the recent past, both human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells have been reported to harbour the potential to differentiate into primordial germ cells and gametes. We here discuss the possibility to use human amniotic fluid stem (AFS) cells as a biological model. Since their discovery in 2003, AFS cells have been characterized to differentiate into cells of all three germ layers, to be genomically stable, to have a high proliferative potential and to be non-tumourigenic. In addition, AFS cells are not subject of ethical concerns. In contrast to iPS cells, AFSs cells do not need ectopic induction of pluripotency, which is often associated with only imperfectly cleared epigenetic memory of the source cells. Since AFS cells can be derived from amniocentesis with disease-causing mutations and can be transfected with high efficiency, they could be used in probing gene functions for spermatogenesis and in screening for male reproductive toxicity.

  7. Amniotic fluid stem cell-based models to study the effects of gene mutations and toxicants on male germ cell formation

    PubMed Central

    Gundacker, Claudia; Dolznig, Helmut; Mikula, Mario; Rosner, Margit; Brandau, Oliver; Hengstschläger, Markus

    2012-01-01

    Male infertility is a major public health issue predominantly caused by defects in germ cell development. In the past, studies on the genetic regulation of spermatogenesis as well as on negative environmental impacts have been hampered by the fact that human germ cell development is intractable to direct analysis in vivo. Compared with model organisms including mice, there are fundamental differences in the molecular processes of human germ cell development. Therefore, an in vitro model mimicking human sperm formation would be an extremely valuable research tool. In the recent past, both human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells have been reported to harbour the potential to differentiate into primordial germ cells and gametes. We here discuss the possibility to use human amniotic fluid stem (AFS) cells as a biological model. Since their discovery in 2003, AFS cells have been characterized to differentiate into cells of all three germ layers, to be genomically stable, to have a high proliferative potential and to be non-tumourigenic. In addition, AFS cells are not subject of ethical concerns. In contrast to iPS cells, AFSs cells do not need ectopic induction of pluripotency, which is often associated with only imperfectly cleared epigenetic memory of the source cells. Since AFS cells can be derived from amniocentesis with disease-causing mutations and can be transfected with high efficiency, they could be used in probing gene functions for spermatogenesis and in screening for male reproductive toxicity. PMID:22231297

  8. A numerical study of the relationship between atmospheric forcing, cold intermediate layer generation and primary production in the Black Sea over interannual time scales

    NASA Astrophysics Data System (ADS)

    Cannaby, Heather

    2015-04-01

    The Cold Intermediate Layer (CIL) is a characteristic feature of the Black Sea formed during winter when cool surface waters penetrate to the depth of the upper halocline. The CIL typically persists throughout the year and is defined at its upper and lower boundaries by the 8 °C isotherm. CIL formation is concentrated in the central regions of the Black Sea basin and on the NW shelf, although the relative contribution of these two sources is still debated. Previous studies have suggested that CIL formation on the NW shelf may play an important role in the subduction of nutrient rich shelf waters into the upper pycnocline, thus removing nutrients from the euphotic zone and impacting rates of primary production. A 20 year hydrodynamic model (Princeton Ocean Model) simulation extending from 1990-2009 and forced by the DMI atmospheric reanalysis is used to investigate (i) interactions between atmospheric forcing and regional CIL formation and (ii) rates of CIL formation and the subduction of NW shelf waters to depths below the euphotic zone. Model skill in simulating CIL characteristics is demonstrated. Results suggest that the ratio of CIL waters formed in the central regions of the Black Sea basin and on the NW shelf varies considerably from one year to another due to sub-domain scale atmospheric variability. Exceptionally warm years when CIL formation is considerably reduced are associated with anomalously high concentrations of fresh riverine water residing in the euphotic zone, and hence a higher percentage of riverine nutrients are available to fuel primary production. Years when anomalously large volumes of CIL water are formed on the NW shelf are not necessarily cold years when considering the domain as a whole. During these years an anomalously high volume of riverine water is subducted into the CIL where it remains trapped throughout the following spring and summer. This study provides a physics based explanation for the occurrence of higher phytoplankton

  9. Composition and molecular weight distribution of carob germ protein fractions.

    PubMed

    Smith, Brennan M; Bean, Scott R; Schober, Tilman J; Tilley, Michael; Herald, Thomas J; Aramouni, Fadi

    2010-07-14

    Biochemical properties of carob germ proteins were analyzed using a combination of selective extraction, reversed-phase high-performance liquid chromatography (RP-HPLC), size exclusion chromatography (SEC) coupled with multiangle laser light scattering (SEC-MALS), and electrophoretic analysis. Using a modified Osborne extraction procedure, carob germ flour proteins were found to contain approximately 32% albumin and globulin and approximately 68% glutelin with no prolamins detected. The albumin and globulin fraction was found to contain low amounts of disulfide-bonded polymers with relatively low M(w) ranging up to 5 x 10(6) Da. The glutelin fraction, however, was found to contain large amounts of high molecular weight disulfide-bonded polymers with M(w) up to 8 x 10(7) Da. When extracted under nonreducing conditions and divided into soluble and insoluble proteins as typically done for wheat gluten, carob germ proteins were found to be almost entirely ( approximately 95%) in the soluble fraction with only ( approximately 5%) in the insoluble fraction. As in wheat, SEC-MALS analysis showed that the insoluble proteins had a greater M(w) than the soluble proteins and ranged up to 8 x 10(7) Da. The lower M(w) distribution of the polymeric proteins of carob germ flour may account for differences in functionality between wheat and carob germ flour.

  10. Vanadium induced ultrastructural changes and apoptosis in male germ cells.

    PubMed

    Aragón, M A; Ayala, M E; Fortoul, T I; Bizarro, P; Altamirano-Lozano, M

    2005-01-01

    Vanadium is a transition metal that is emitted to the atmosphere during combustion of fossil fuels. In the environment, vanadium occurs in the (V) oxidized form, but in the body it is found exclusively in the (IV) oxidized form. Vanadium tetraoxide is an inorganic chemical species in the (IV) oxidized form that has been shown to induce toxic effects in vitro and in vivo. The reproductive toxicity of vanadium in males was studied through monitoring germ cell apoptosis during spermatogenesis. We analyzed ultrastructural damage, and testosterone and progesterone concentrations following vanadium tetraoxide administered to male mice for 60 days. Spermatogenesis stages I-III and X-XII frequently showed apoptotic germ cells in control and treated animals; vanadium tetraoxide treatment induced an increase in the number of germ cell apoptosis in stages I-III and XII at 9.4 and 18.8 mg/kg, respectively. Although spermatogenesis is regulated by testosterone, in our study this hormone level was not modified by vanadium administration; thus, germ cell death was not related with testosterone concentration. At the ultrastructural level, we observed inclusion structures that varied as to location and content in the Sertoli and germ cells. PMID:15808796

  11. Mechanisms and chemical induction of aneuploidy in rodent germ cells

    SciTech Connect

    Mailhes, J B; Marchetti, F

    2004-10-15

    The objective of this review is to suggest that the advances being made in our understanding of the molecular events surrounding chromosome segregation in non-mammalian and somatic cell models be considered when designing experiments for studying aneuploidy in mammalian germ cells. Accurate chromosome segregation requires the temporal control and unique interactions among a vast array of proteins and cellular organelles. Abnormal function and temporal disarray among these, and others to be inidentified, biochemical reactions and cellular organelles have the potential for predisposing cells to aneuploidy. Although numerous studies have demonstrated that certain chemicals (mainly those that alter microtubule function) can induce aneuploidy in mammalian germ cells, it seems relevant to point out that such data can be influenced by gender, meiotic stage, and time of cell-fixation post-treatment. Additionally, a consensus has not been reached regarding which of several germ cell aneuploidy assays most accurately reflects the human condition. More recent studies have shown that certain kinase, phosphatase, proteasome, and topoisomerase inhibitors can also induce aneuploidy in rodent germ cells. We suggest that molecular approaches be prudently incorporated into mammalian germ cell aneuploidy research in order to eventually understand the causes and mechanisms of human aneuploidy. Such an enormous undertaking would benefit from collaboration among scientists representing several disciplines.

  12. Germ Cell Nuclear Factor Regulates Gametogenesis in Developing Gonads

    PubMed Central

    Sabour, Davood; Xu, Xueping; Chung, Arthur C. K.; Le Menuet, Damien; Ko, Kinarm; Tapia, Natalia; Araúzo-Bravo, Marcos J.; Gentile, Luca; Greber, Boris; Hübner, Karin; Sebastiano, Vittorio; Wu, Guangming; Schöler, Hans R.; Cooney, Austin J.

    2014-01-01

    Expression of germ cell nuclear factor (GCNF; Nr6a1), an orphan member of the nuclear receptor gene family of transcription factors, during gastrulation and neurulation is critical for normal embryogenesis in mice. Gcnf represses the expression of the POU-domain transcription factor Oct4 (Pou5f1) during mouse post-implantation development. Although Gcnf expression is not critical for the embryonic segregation of the germ cell lineage, we found that sexually dimorphic expression of Gcnf in germ cells correlates with the expression of pluripotency-associated genes, such as Oct4, Sox2, and Nanog, as well as the early meiotic marker gene Stra8. To elucidate the role of Gcnf during mouse germ cell differentiation, we generated an ex vivo Gcnf-knockdown model in combination with a regulated CreLox mutation of Gcnf. Lack of Gcnf impairs normal spermatogenesis and oogenesis in vivo, as well as the derivation of germ cells from embryonic stem cells (ESCs) in vitro. Inactivation of the Gcnf gene in vivo leads to loss of repression of Oct4 expression in both male and female gonads. PMID:25140725

  13. Cystic trophoblastic tumor: a nonaggressive lesion in postchemotherapy resections of patients with testicular germ cell tumors.

    PubMed

    Ulbright, Thomas M; Henley, John D; Cummings, Oscar W; Foster, Richard S; Cheng, Liang

    2004-09-01

    Cystic trophoblastic tumor (CTT) is an uncommon lesion that is usually seen after chemotherapy in patients with testicular germ cell tumors. Its clinical significance has not been well studied. We identified 17 patients with CTT in retroperitoneal lymph node dissections (RPLNDs) after cisplatin-based chemotherapy for testicular germ cell tumors. None had other forms of persistent germ cell tumor except for teratoma, and no patient received additional chemotherapy after RPLND. At the time of RPLND, 7 patients were known to have had normal serum levels of beta-subunit of human chorionic gonadotropin (beta-hCG), whereas 5 had relatively mild elevations (1.6-165 mIU/mL, median, 8.0 mIU/mL). The CTTs consisted of circumscribed, small cysts, usually multifocal, lined by mostly mononucleated trophoblast cells with abundant eosinophilic cytoplasm, often with smudged nuclei and showing only infrequent mitotic figures. Although the epithelial lining was often stratified to several layers in thickness or formed intracystic papillary tufts, solid proliferations of trophoblast cells within the stroma were absent, as were clearly biphasic admixtures of mononucleated and multinucleated trophoblast cells. The cysts were either empty or contained fibrinoid material and were set in a hypocellular, fibrous stroma with adjacent teratoma. Stains for hCG highlighted rare cells. On follow-up of 15 patients, 11 were disease free (mean, 80 months). Three recurred with serum alpha-fetoprotein elevations at 25, 31, and 107 months, respectively, and one with beta-hCG elevation at 2 months. The latter patient, however, also had unresected mediastinal tumor postchemotherapy. We conclude that the finding of CTT in postchemotherapy resections does not warrant additional chemotherapy. Its clinical significance appears similar to that of residual teratoma.

  14. [Evaluation of cookies enriched with corn germ and soy fiber].

    PubMed

    Rebolledo, M A; Sangronis, E; Barbosa-Cánovas, G V

    1999-09-01

    The objective of this study was to evaluate four cookie formulations which wheat flour was partially substituted by free-fat corn germ flour and/or soy fiber. Baking quality, protein, fat, ash, dietary fiber, hardness, color, Protein Efficiency Ratio PER and Apparent Digestibility in vivo were determined. A trained panel evaluated color, hardness and fracturability of cookies. Dietary fiber of cookies varied from 8.2 to 24.9% and protein from 11.3 to 12.7%. The source and amount of dietary fiber modified physical, sensory, and nutritional properties of cookies. Cookies formulated with 20% corn germ flour gave the highest PER, Digestibility Aparente in vivo, and acceptance by consumers. This study demonstrated the potential use of free-fat corn germ and soy fiber as functional ingredients.

  15. Salvage Therapy for Patients With Germ Cell Tumor.

    PubMed

    Rashdan, Sawsan; Einhorn, Lawrence H

    2016-05-01

    The introduction of cisplatin combination chemotherapy, 40 years ago, transformed metastatic testicular germ cell tumors from an almost uniformly fatal disease into a model for a curable neoplasm. Before the era of platinum combination chemotherapy, the 5-year survival rate among men with metastatic testicular germ cell tumors was 5% to 10%. Currently, the 5-year survival rate is 80% for patients with metastatic disease and 95% overall. Despite the substantial advances in the treatment of germ cell tumors, 20% to 30% of patients will relapse after first-line chemotherapy and will require additional salvage therapies. Standard-dose or high-dose chemotherapy can cure ≤ 50% of these patients. Relapses after high-dose chemotherapy generally carry a poor prognosis; however, cure is still possible in a small percentage of patients by using further salvage chemotherapy or salvage surgery. PMID:27170693

  16. Giant Mediastinal Germ Cell Tumour: An Enigma of Surgical Consideration

    PubMed Central

    Ali, Nurayub Mohd; Azizan, Nornazirah; Zakaria, Andee Dzulkarnaen; Rahman, Mohd Ramzisham Abdul

    2016-01-01

    We present a case of 16-year-old male, who was referred from private centre for dyspnoea, fatigue, and orthopnea. The chest radiograph revealed complete opacification of left chest which was confirmed by computed tomography as a large left mediastinal mass measuring 14 × 15 × 18 cm. The diagnostic needle core biopsy revealed mixed germ cell tumour with possible combination of embryonal carcinoma, yolk sac, and teratoma. After 4 cycles of neoadjuvant BEP regime, there was initial response of tumour markers but not tumour bulk. Instead of classic median sternotomy or clamshell incision, posterolateral approach with piecemeal manner was chosen. Histology confirmed mixed germ cell tumour with residual teratomatous component without yolk sac or embryonal carcinoma component. Weighing 3.5 kg, it is one of the largest mediastinal germ cell tumours ever reported. We describe this rare and gigantic intrathoracic tumour and discuss the spectrum of surgical approach and treatment of this exceptional tumour. PMID:27807495

  17. Corticocortical connections of cat primary somatosensory cortex.

    PubMed

    Schwark, H D; Esteky, H; Jones, E G

    1992-01-01

    The organization of corticocortical connections in the representation of the forepaw in cat primary somatosensory cortex (SI) was studied following injections of various tracers into different cortical cytoarchitectonic areas. Small injections of horseradish peroxidase, wheat germ agglutinin-conjugated HRP, Phaseolus vulgaris leukoagglutinin, or fast blue were placed into the representation of the forepaw in areas 3b, 1, or 2. The positions of labeled neurons in SI and the surrounding cortical areas were plotted on flattened surface reconstructions to determine the organization of the corticocortical connections within SI. A strong, reciprocal projection linked the two forepaw representations which have been described in area 3b and the part of area 2 which lies in the anterior bank of the lateral ansate sulcus (see Iwamura and Tanaka 1978a, b). Dense projections also linked these areas with SII, as previously reported (Burton and Kopf 1984a). Additional projections to area 3b arose primarily from areas 3a and 1. Projections to area 2 were more widespread than those to area 3b, and arose from all other areas of SI as well as from areas 4 and 5a. All injections into SI tended to label groups of neurons which lay in mediolateral strips. Corticocortical projection neurons which were most heavily labeled by SI injections were pyramidal cells in layer III. Additional projections from area 2 to 3b, area 5a to 2, and SII to areas 2 and 3b arose from layer VI as well. Although neurons of layers III and VI were always the most densely labeled, large injections into SI labeled neurons in layers II and V as well. PMID:1282890

  18. Identification of a putative germ plasm in the amphipod Parhyale hawaiensis

    PubMed Central

    2013-01-01

    Background Specification of the germ line is an essential event during the embryonic development of sexually reproducing animals, as germ line cells are uniquely capable of giving rise to the next generation. Animal germ cells arise through either inheritance of a specialized, maternally supplied cytoplasm called 'germ plasm’ or though inductive signaling by somatic cells. Our understanding of germ cell determination is based largely on a small number of model organisms. To better understand the evolution of germ cell specification, we are investigating this process in the amphipod crustacean Parhyale hawaiensis. Experimental evidence from previous studies demonstrated that Parhyale germ cells are specified through inheritance of a maternally supplied cytoplasmic determinant; however, this determinant has not been identified. Results Here we show that the one-cell stage Parhyale embryo has a distinct cytoplasmic region that can be identified by morphology as well as the localization of germ line-associated RNAs. Removal of this cytoplasmic region results in a loss of embryonic germ cells, supporting the hypothesis that it is required for specification of the germ line. Surprisingly, we found that removal of this distinct cytoplasm also results in aberrant somatic cell behaviors, as embryos fail to gastrulate. Conclusions Parhyale hawaiensis embryos have a specialized cytoplasm that is required for specification of the germ line. Our data provide the first functional evidence of a putative germ plasm in a crustacean and provide the basis for comparative functional analysis of germ plasm formation within non-insect arthropods. PMID:24314239

  19. Functional Analysis of the Drosophila Embryonic Germ Cell Transcriptome by RNA Interference

    PubMed Central

    Bujna, Ágnes; Vilmos, Péter; Spirohn, Kerstin; Boutros, Michael; Erdélyi, Miklós

    2014-01-01

    In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitantly with the degradation of the maternal transcripts. Thus, during embryogenesis, maternally provided and zygotically transcribed mRNAs determine germ cell development collectively. In an effort to identify novel genes involved in the regulation of germ cell behavior, we carried out a large-scale RNAi screen targeting both maternal and zygotic components of the embryonic germ line transcriptome. We identified 48 genes necessary for distinct stages in germ cell development. We found pebble and fascetto to be essential for germ cell migration and germ cell division, respectively. Our data uncover a previously unanticipated role of mei-P26 in maintenance of embryonic germ cell fate. We also performed systematic co-RNAi experiments, through which we found a low rate of functional redundancy among homologous gene pairs. As our data indicate a high degree of evolutionary conservation in genetic regulation of germ cell development, they are likely to provide valuable insights into the biology of the germ line in general. PMID:24896584

  20. Germ-cell malignant tumours in father and son.

    PubMed Central

    Musa, M. B.

    1975-01-01

    Germ-cell malignant tumours occurred in a man and his son. The father, who had a teratoma of the right testicle removed 24 years ago, is presently alive and well. The son, who had a choriocarcinoma presenting as an abdominal mass, possibly originating in the testicle, died within 7 months of the diagnosis with metastases in the lungs, liver and retroperitoneum. This report documents the third such case of germ-cell neoplasms occurring in father and son. Images FIG. 1 FIG. 2 FIG. 3 PMID:1168534

  1. Germ-line gene therapy and the medical imperative.

    PubMed

    Munson, Ronald; Davis, Lawrence H

    1992-06-01

    Somatic cell gene therapy has yielded promising results. If germ cell gene therapy can be developed, the promise is even greater: hundreds of genetic diseases might be virtually eliminated. But some claim the procedure is morally unacceptable. We thoroughly and sympathetically examine several possible reasons for this claim but find them inadequate. There is no moral reason, then, not to develop and employ germ-line gene therapy. Taking the offensive, we argue next that medicine has a prima facie moral obligation to do so.

  2. A functional genomic screen in planarians identifies novel regulators of germ cell development

    PubMed Central

    Wang, Yuying; Stary, Joel M.; Wilhelm, James E.; Newmark, Phillip A.

    2010-01-01

    Germ cells serve as intriguing examples of differentiated cells that retain the capacity to generate all cell types of an organism. Here we used functional genomic approaches in planarians to identify genes required for proper germ cell development. We conducted microarray analyses and in situ hybridization to discover and validate germ cell-enriched transcripts, and then used RNAi to screen for genes required for discrete stages of germ cell development. The majority of genes we identified encode conserved RNA-binding proteins, several of which have not been implicated previously in germ cell development. We also show that a germ cell-specific subunit of the conserved transcription factor CCAAT-binding protein/nuclear factor-Y is required for maintaining spermatogonial stem cells. Our results demonstrate that conserved transcriptional and post-transcriptional mechanisms regulate germ cell development in planarians. These findings suggest that studies of planarians will inform our understanding of germ cell biology in higher organisms. PMID:20844018

  3. Novel strong tissue specific promoter for gene expression in human germ cells

    PubMed Central

    2010-01-01

    Background Tissue specific promoters may be utilized for a variety of applications, including programmed gene expression in cell types, tissues and organs of interest, for developing different cell culture models or for use in gene therapy. We report a novel, tissue-specific promoter that was identified and engineered from the native upstream regulatory region of the human gene NDUFV1 containing an endogenous retroviral sequence. Results Among seven established human cell lines and five primary cultures, this modified NDUFV1 upstream sequence (mNUS) was active only in human undifferentiated germ-derived cells (lines Tera-1 and EP2102), where it demonstrated high promoter activity (~twice greater than that of the SV40 early promoter, and comparable to the routinely used cytomegaloviral promoter). To investigate the potential applicability of the mNUS promoter for biotechnological needs, a construct carrying a recombinant cytosine deaminase (RCD) suicide gene under the control of mNUS was tested in cell lines of different tissue origin. High cytotoxic effect of RCD with a cell-death rate ~60% was observed only in germ-derived cells (Tera-1), whereas no effect was seen in a somatic, kidney-derived control cell line (HEK293). In further experiments, we tested mNUS-driven expression of a hyperactive Sleeping Beauty transposase (SB100X). The mNUS-SB100X construct mediated stable transgene insertions exclusively in germ-derived cells, thereby providing further evidence of tissue-specificity of the mNUS promoter. Conclusions We conclude that mNUS may be used as an efficient promoter for tissue-specific gene expression in human germ-derived cells in many applications. Our data also suggest that the 91 bp-long sequence located exactly upstream NDUFV1 transcriptional start site plays a crucial role in the activity of this gene promoter in vitro in the majority of tested cell types (10/12), and an important role - in the rest two cell lines. PMID:20716342

  4. DNA Analysis in Samples From Younger Patients With Germ Cell Tumors and Their Parents or Siblings

    ClinicalTrials.gov

    2016-10-05

    Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Ovarian Choriocarcinoma; Ovarian Embryonal Carcinoma; Ovarian Mixed Germ Cell Tumor; Ovarian Teratoma; Ovarian Yolk Sac Tumor; Testicular Choriocarcinoma; Testicular Embryonal Carcinoma; Testicular Seminoma; Testicular Teratoma; Testicular Yolk Sac Tumor

  5. Improved solubility and emulsification of wet-milled corn germ protein recovered by ultrafiltration-diafiltration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated ultrafiltration-diafiltration (UFDF) as a means to improve the extractability of wet-milled corn germ protein and determined its effects on the functional properties of the recovered protein product. Wet germ (WG) and finished germ (FG) proteins (Pr) were extracted by using 0.1M...

  6. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect.

    PubMed

    Ewen-Campen, Ben; Jones, Tamsin E M; Extavour, Cassandra G

    2013-06-15

    Primordial germ cell (PGC) formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this "germ plasm" acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola) suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects. PMID:23789106

  7. Regulative germ cell specification in axolotl embryos: a primitive trait conserved in the mammalian lineage.

    PubMed

    Johnson, Andrew D; Crother, Brian; White, Mary E; Patient, Roger; Bachvarova, Rosemary F; Drum, Matthew; Masi, Thomas

    2003-08-29

    How germ cells are specified in the embryos of animals has been a mystery for decades. Unlike most developmental processes, which are highly conserved, embryos specify germ cells in very different ways. Curiously, in mouse embryos germ cells are specified by extracellular signals; they are not autonomously specified by maternal germ cell determinants (germ plasm), as are the germ cells in most animal model systems. We have developed the axolotl (Ambystoma mexicanum), a salamander, as an experimental system, because classic experiments have shown that the germ cells in this species are induced by extracellular signals in the absence of germ plasm. Here, we provide evidence that the germ cells in axolotls arise from naive mesoderm in response to simple inducing agents. In addition, by analysing the sequences of axolotl germ-cell-specific genes, we provide evidence that mice and urodele amphibians share a common mechanism of germ cell development that is ancestral to tetrapods. Our results imply that germ plasm, as found in species such as frogs and teleosts, is the result of convergent evolution. We discuss the evolutionary implications of our findings. PMID:14511484

  8. The growing teratoma syndrome: an unusual manifestation of treated, nonseminomatous germ cell tumors of the testis.

    PubMed

    Lorigan, J G; Eftekhari, F; David, C L; Shirkhoda, A

    1988-08-01

    Residual masses are a common finding after chemotherapy for retroperitoneal and other metastases from nonseminomatous germ cell tumors of the testis. These may contain mature teratoma, fibrotic tissue, or tumor. Mature teratoma, which is unresponsive to chemotherapy, may result from evolution of a malignant lesion during treatment, or it may represent a metastasis from a focus of mature teratoma in the primary testicular tumor. An enlarging retroperitoneal mass during the course of chemotherapy is usually due to treatment failure but rarely may be due to an enlarging mature teratoma, the so-called growing teratoma syndrome. This report concerns five patients with nonseminomatous germ cell tumors metastatic to the retroperitoneum in whom mature teratomas were found at surgery. These tumors had grown despite the administration of combination systemic chemotherapy, and the cystic component had increased in size. Three patients had evidence of urinary tract compression, three had vascular compression or displacement, and one had gastrointestinal compression. The retroperitoneal mass was excised in each patient, and all are alive 4-27 months after surgery without evidence of recurrence. Growing mature teratoma is unresponsive to chemotherapy but is cured by surgical excision. The possibility of the growing teratoma syndrome should be considered so that these lesions can be treated appropriately.

  9. Genetic and molecular analysis of chlorambucil-induced germ-line mutations in the mouse

    SciTech Connect

    Rinchik, E.M.; Bangham, J.W.; Hunsicker, P.R.; Cacheiro, N.L.A.; Russell, L.B. ); Kwon, B.S. ); Jackson, I.J. )

    1990-02-01

    Eighteen variants recovered from specific locus mutation rate experiments involving the mutagen chlorambucil were subjected to several genetic and molecular analyses. Most mutations were found to be homozygous lethal. Because lethality is often presumptive evidence for multilocus-deletion events, 10 mutations were analyzed by Southern blot analysis with probes at, or closely linked to, several of the specific locus test markers, namely, albino (c), brown (b), and dilute (d). All eight mutations (two c; three b; two d; and one dilute-short ear (Df(d se))) that arose in post-spermatogonial germ cells were deleted for DNA sequences. No evidence for deletion of two d-se region probes was obtained for the remaining two d mutations that arose in stem-cell spermatogonia. Six of the primary mutants also produced low litter sizes (semisterility). Karyotypic analysis has, to date, confirmed the presence of reciprocal translocations in four of the six. The high frequency of deletions and translocations among the mutations induced in post-spermatogonial stages by chlorambucil, combined with its overall high efficiency in inducing mutations in these stages, should make chlorambucil mutagenesis useful for generating experimentally valuable germ-line deletions throughout the mouse genome.

  10. Composition and Molecular Weight Distribution of Carob Germ Proteins Fractions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochemical properties of carob germ proteins were analyzed using a combination of selective extraction, reversed-phase high performance liquid chromatography (RP-HPLC), size exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALS) and electrophoretic analysis. Using a mo...

  11. Declaring the Existence of Human Germ-Cell Mutagens

    EPA Science Inventory

    After more than 80 years of searching for human germ-cell mutagens, I think that sufficient evidence already exists for a number of agents to be so considered, and definitive confirmation seems imminent due to the application ofrecently developed genomic techniques. In preparatio...

  12. Crucial Genes and Pathways in Chicken Germ Stem Cell Differentiation

    PubMed Central

    Zhang, Zhentao; Elsayed, Ahmed Kamel; Shi, Qingqing; Zhang, Yani; Zuo, Qisheng; Li, Dong; Lian, Chao; Tang, Beibei; Xiao, Tianrong; Xu, Qi; Chang, Guobin; Chen, Guohong; Zhang, Lei; Wang, Kehua; Wang, Yingjie; Jin, Kai; Wang, Yilin; Song, Jiuzhou; Cui, Hengmi; Li, Bichun

    2015-01-01

    Male germ cell differentiation is a subtle and complex regulatory process. Currently, its regulatory mechanism is still not fully understood. In our experiment, we performed the first comprehensive genome and transcriptome-wide analyses of the crucial genes and signaling pathways in three kinds of crucial cells (embryonic stem cells, primordial germ cell, and spermatogonial stem cells) that are associated with the male germ cell differentiation. We identified thousands of differentially expressed genes in this process, and from these we chose 173 candidate genes, of which 98 genes were involved in cell differentiation, 19 were involved in the metabolic process, and 56 were involved in the differentiation and metabolic processes, like GAL9, AMH, PLK1, and PSMD7 and so on. In addition, we found that 18 key signaling pathways were involved mainly in cell proliferation, differentiation, and signal transduction processes like TGF-β, Notch, and Jak-STAT. Further exploration found that the candidate gene expression patterns were the same between in vitro induction experiments and transcriptome results. Our results yield clues to the mechanistic basis of male germ cell differentiation and provide an important reference for further studies. PMID:25847247

  13. Obese Kids Have Different Germs in Their Gut

    MedlinePlus

    ... Germs in Their Gut Targeting specific types of bacteria might one day help treat childhood obesity, research suggests To use the sharing features on ... to a way to target specific species of bacteria and help prevent or treat early onset obesity. For the study, the researchers analyzed the gut ...

  14. Primordial germ cells in the embryos of Medaka fish.

    PubMed

    Ijiri, K; Narita, T; Mizuno, R

    1996-10-01

    In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly 'space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

  15. Wheat germ: not only a by-product.

    PubMed

    Brandolini, Andrea; Hidalgo, Alyssa

    2012-03-01

    The wheat germ (embryonic axis and scutellum) represents about 2.5-3.8% of total seed weight and is an important by-product of the flour milling industry. The germ contains about 10-15% lipids, 26-35% proteins, 17% sugars, 1.5-4.5% fibre and 4% minerals, as well as significant quantities of bioactive compounds such as tocopherols [300-740 mg/kg dry matter (DM)], phytosterols (24-50 mg/kg), policosanols (10 mg/kg), carotenoids (4-38 mg/kg), thiamin (15-23 mg/kg) and riboflavin (6-10 mg/kg). Oil recovery is achieved by mechanical pressing or solvent extraction, which retrieve about 50% or 90% lipids, respectively; innovative approaches, such as supercritical carbon dioxide extraction, are also proposed. The oil is rich in triglycerides (57% of total lipids), mainly linoleic (18:2), palmitic (16:0) and oleic (18:1) acids, but relevant amounts of sterols, mono- and diglycerides, phospho- and glycolipids are present. The lypophilic antioxidants tocopherols and carotenoids are also abundant. The main by-product of oil extraction is defatted germ meal, which has high protein content (30-32%), is rich in albumin (34.5% of total protein) and globulin (15.6%), and thus presents a well-balanced amino acid profile. Its principal mineral constituents are potassium, magnesium, calcium, zinc and manganese, in decreasing order. Total flavonoid content is about 0.35 g rutin equivalent/100 g DM. The wheat germ is therefore a unique source of concentrated nutrients, highly valued as food supplement. While the oil is widely appreciated for its pharmaceutical and nutritional value, the defatted germ meal is a promising source of high-quality vegetable proteins. Better nutrient separation from the kernel and improved fractioning techniques could also provide high-purity molecules with positive health benefits. PMID:22077851

  16. Wheat germ: not only a by-product.

    PubMed

    Brandolini, Andrea; Hidalgo, Alyssa

    2012-03-01

    The wheat germ (embryonic axis and scutellum) represents about 2.5-3.8% of total seed weight and is an important by-product of the flour milling industry. The germ contains about 10-15% lipids, 26-35% proteins, 17% sugars, 1.5-4.5% fibre and 4% minerals, as well as significant quantities of bioactive compounds such as tocopherols [300-740 mg/kg dry matter (DM)], phytosterols (24-50 mg/kg), policosanols (10 mg/kg), carotenoids (4-38 mg/kg), thiamin (15-23 mg/kg) and riboflavin (6-10 mg/kg). Oil recovery is achieved by mechanical pressing or solvent extraction, which retrieve about 50% or 90% lipids, respectively; innovative approaches, such as supercritical carbon dioxide extraction, are also proposed. The oil is rich in triglycerides (57% of total lipids), mainly linoleic (18:2), palmitic (16:0) and oleic (18:1) acids, but relevant amounts of sterols, mono- and diglycerides, phospho- and glycolipids are present. The lypophilic antioxidants tocopherols and carotenoids are also abundant. The main by-product of oil extraction is defatted germ meal, which has high protein content (30-32%), is rich in albumin (34.5% of total protein) and globulin (15.6%), and thus presents a well-balanced amino acid profile. Its principal mineral constituents are potassium, magnesium, calcium, zinc and manganese, in decreasing order. Total flavonoid content is about 0.35 g rutin equivalent/100 g DM. The wheat germ is therefore a unique source of concentrated nutrients, highly valued as food supplement. While the oil is widely appreciated for its pharmaceutical and nutritional value, the defatted germ meal is a promising source of high-quality vegetable proteins. Better nutrient separation from the kernel and improved fractioning techniques could also provide high-purity molecules with positive health benefits.

  17. Prenatal exposure to chromium induces early reproductive senescence by increasing germ cell apoptosis and advancing germ cell cyst breakdown in the F1 offspring

    PubMed Central

    Sivakumar, Kirthiram K.; Stanley, Jone A.; Arosh, Joe A.; Pepling, Melissa E.; Burghardt, Robert C.; Banu, Sakhila K.

    2014-01-01

    Hexavalent chromium (CrVI), one of the more toxic heavy metals, is widely used in more than 50 industries such as chrome plating, welding, wood processing and tanneries. As one of the world’s leading producers of chromium compounds, the U.S. is facing growing challenges in protecting human health against multiple adverse effects of CrVI. CrVI is rapidly converted to CrIII intracellularly, and can induce apoptosis through different mechanisms. Our previous studies demonstrated postnatal exposure to CrVI results in a delay or arrest in follicle development and puberty. Pregnant rats were treated with 25 ppm potassium dichromate (CrVI) from gestational day (GD) 9.5 to 14.5 through drinking water, placentae were removed on GD 20, and total Cr was estimated in the placentae; ovaries were removed from the F1 offspring on postnatal day (PND)-1 and various analyses were performed. Our results show that gestational exposure to CrVI resulted in (i) increased Cr concentration in the placenta, (ii) increased germ cell apoptosis by up-regulating p53/p27–Bax–caspase-3 proteins and by increasing p53–SOD-2 co-localization; (iii) accelerated germ cell cyst (GCC) breakdown; (iv) advanced primordial follicle assembly and primary follicle transition and (v) down regulation of p-AKT, p-ERK and XIAP. As a result of the above events, CrVI induced early reproductive senescence and decrease in litter size in F1 female progeny. PMID:24530425

  18. Anastomosis of germ tubes and nuclear migration of nuclei in germ tube networks of the soybean rust pathogen, Phakopsora pachyrhizi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasexual recombination through hyphal anastomosis is an important mechanism for genetic diversity in filamentous fungi. In this study, we observed fusion of germ tubes in germinating urediniospores of Phakopsora pachyrhizi resulting in a complex hyphal network. Staining of the germinating uredinio...

  19. Production of loach (Misgurnus anguillicaudatus) germ-line chimera using transplantation of primordial germ cells isolated from cryopreserved blastomeres.

    PubMed

    Yasui, G S; Fujimoto, T; Sakao, S; Yamaha, E; Arai, K

    2011-08-01

    An efficient procedure for the cryopreservation of fish blastomeres followed by restoration through germ-line chimera formation was established. Blastomeres of the loach (Misgurnus anguillicaudatus) were cryopreserved in 250-µL straws in Eagle's minimum essential medium with various concentrations of dimethyl-sulfoxide (0, 5, 10, 15, and 20%), and the best concentration was combined with glycerol (1, 2, and 4%) and external cryoprotectants (1 or 2% sucrose; 2, 5, or 10% fetal bovine serum; 1 or 2% BSA). Postthaw viability of the blastomeres was used to optimize cryopreservation conditions. Donor blastomeres were injected with zebrafish green fluorescence protein-nos1 3' untranslated region mRNA and biotin dextran before cryopreservation in the optimal freeze medium. Host embryos were injected with zebrafish DsRed-nos1 3' untranslated region mRNA and reared to the blastula stage. Donor blastomeres were thawed at 25 °C for 10 s and transplanted to the host embryos either immediately or after incubation for 16 h at 20 °C. Donor and host primordial germ cell migration was visualized with fluorescent imaging during the early stages of embryogenesis, and also by histology in 4-d-old embryos. Transplantation of blastomeres immediately after thawing gave decreased hatching rates (approximately 3%) and generated a smaller percentage of germ-line chimeras (approximately 1.1%). In contrast, incubation of a cryopreserved sample for 16 h followed by transplantation of the green fluorescence protein-positive blastomeres improved the hatching rate to 90%, and successfully produced presumable germ-line chimeras at a rate of 16.5%. The improved survival rates and germ-line chimerism may be an effective method for gene banking and subsequent reconstitution of endangered fish genotypes.

  20. Induction of Germ Cell-like Cells from Porcine Induced Pluripotent Stem Cells

    PubMed Central

    Wang, Hanning; Xiang, Jinzhu; Zhang, Wei; Li, Junhong; Wei, Qingqing; Zhong, Liang; Ouyang, Hongsheng; Han, Jianyong

    2016-01-01

    The ability to generate germ cells from pluripotent stem cells (PSCs) is valuable for human regenerative medicine and animal breeding. Germ cell-like cells (GCLCs) have been differentiated from mouse and human PSCs, but not from porcine PSCs, which are considered an ideal model for stem cell applications. Here, we developed a defined culture system for the induction of primordial germ cell-like cells (PGCLCs) from porcine induced PSCs (piPSCs). The identity of the PGCLCs was characterized by observing cell morphology, detecting germ cell marker gene expression and evaluating epigenetic properties. PGCLCs could further differentiate into spermatogonial stem cell-like cells (SSCLCs) in vitro. Importantly, meiosis occurred during SSCLC induction. Xenotransplantation of GCLCs into seminiferous tubules of infertile immunodeficient mice resulted in immunohistochemically identifiable germ cells in vivo. Overall, our study provides a feasible strategy for directing piPSCs to the germ cell fate and lays a foundation for exploring germ cell development mechanisms. PMID:27264660

  1. Germ direct observation by AFM under crystallization of self-organized assemblies of mono-protonated meso-tetraphenylporphine dimers

    NASA Astrophysics Data System (ADS)

    Udal'tsov, Alexander V.

    2016-08-01

    Assemblies consisting of mono-protonated meso-tetraphenylporphine dimers and water have been investigated by UV-vis spectroscopy in solution and atomic force microscopy (AFM) in thin layers. These assemblies self-organized into domains produce microcrystals in thin layer. Morphology of the microcrystals and characteristic features of crystallization germ on the top found by contact AFM indicate that surface tension of an aqueous layer on the domain generates the crystallization process. Estimations of the pressure producing the germ and bulk modulus (Bm) of microcrystals give 26.3±2.6 MPa and 3.72 GPa and Bm=12.7 GPa obtained for dried thin films. The former modulus is comparable with bulk modulus of water (2.174 GPa) that implies liquid crystals formation. Absorptions of longitudinal optical (LO) phonons with ћωLO=0.3761 and 0.3577 eV, which are arisen because of hole polaron moving through water, are found in the electronic spectra of the assemblies. The crystallization is suggested to occur due to Zundel cation (H5O2+) operation like the water-porphyrin matrix self-organization found earlier.

  2. [Biphasic pulmonary blastoma with germ cell differentiation: a challenge in diagnosis and treatment].

    PubMed

    Teixeira, Alexandra; Vieira, Claúdia; Sousa, Nuno; Begonha, Rosa; Afonso, Mariana; Amaro, Teresina; Maurício, Joaquina

    2011-12-01

    Serviço de Oncologia Médica. Instituto Português de Oncologia Francisco Gentil. Porto. Portugal. A 27-year-old man, smoker, presented with three months history of fever. A left pulmonary mass inseparable from the heart was identified and serum alpha-fetoprotein was 4160 ng/ml. The morphologic aspects and immunohistochemistry of the biopsy specimen, in conjunction with the clinical findings were compatible with a diagnosis of pulmonary blastoma with germ cell differentiation. The tumour was considered unresectable. The patient was submitted to two cycles of primary chemotherapy with bleomycin, etoposide and cisplatin. Despite a reduction in serum alpha-fetoprotein, the tumor did not regress. Second line chemotherapy (with paclitaxel, ifosfamide and cisplatin) was instituted, but progressive disease was identified after 2 cycles. Six months after the diagnosis cerebral metastases were found and the patient died. This case illustrates a rare situation of difficult diagnosis and treatment.

  3. Management of bilateral malignant ovarian germ cell tumors: Experience of a single institute

    PubMed Central

    Zhao, Ting; Liu, Yan; Jiang, Hongyuan; Zhang, Hao; Lu, Yuan

    2016-01-01

    Bilateral malignant ovarian germ cell tumors (MOGCTs) are rare. Determination of the optimal treatment modalities is crucial, as these malignancies mainly affect girls and young women who may wish to preserve their fertility. In order to review the prevalence, clinical characteristics, treatment and outcome of bilateral MOGCTs, we performed a retrospective review of patients who were diagnosed with bilateral MOGCTs and underwent primary surgery at the Obstetrics and Gynecology Hospital of Fudan University (Shanghai, China) between January, 2001 and December, 2014. Of the 130 patients investigated, 8 were diagnosed with bilateral disease, most of whom were International Federation of Gynecology and Obstetrics stage I. There was no significant difference in overall and disease-free survival between patients with unilateral and those with bilateral disease. Cases with dysgerminoma, dysgerminoma coexisting with gonadoblastoma, yolk sac tumor and ovarian primary choriocarcinoma were included in this study. Fertility was spared in 2 patients (1 with dysgerminoma and 1 with ovarian primary choriocarcinoma). The patient with ovarian choriocarcinoma experienced relapse and was finally salvaged by radical surgery and adjuvant chemotherapy. According to our results and the published data, patients affected by bilateral MOGCTs have a satisfactory prognosis. The treatment modalities largely depend on the histological type of the tumor. Fertility-sparing surgery may be safe for patients affected by dysgerminoma, but should be considered with caution in patients with ovarian primary choriocarcinoma. PMID:27446585

  4. Primary human chorionic gonadotropin secreting germinoma of the corpus callosum

    PubMed Central

    Chuan Aaron, Foo Song; Dawn, Chong Q. Q.; Kenneth, Chang T. E.; Hoe, Ng Wai; Yen, Soh Shui; Chee Kian, Tham

    2013-01-01

    Background: Primary intracranial germinomas are a rare subset of intracranial tumors derived from mis-incorporated germ cells within the folding neural plate during embryogenesis. Though known to arise from midline structures in the central nervous system (CNS), occurrence within the corpus callosum is exceedingly rare. Case Description: We present a rare case of secreting primary intracranial germinoma with extensive intraventricular metastasis presenting as a multi-cystic butterfly lesion in the genu of the corpus callosum in a young boy. Conclusion: Intracranial germ cell tumors must be considered for any multi-cystic lesion arising from midline structures in the CNS in the preadult population. PMID:24233184

  5. A rare case of metastatic germ cell tumor to stomach and duodenum masquerading as signet ring cell adenocarcinoma

    PubMed Central

    Sundaram, Sridhar; Patil, Prachi; Mehta, Shaesta; Ramadwar, Mukta

    2016-01-01

    Adenocarcinomas are the most common cancers affecting stomach. However gastrointestinal stromal tumors (GIST), lymphomas and neuroendocrine tumors (NETs) can also affect the stomach. But stomach is relatively rare site of involvement by metastasis. In this case report a rare metastasis of germ cell tumor (GCT) into stomach is described which clinically and endoscopically masquerade as primary gastric cancers. But detailed clinical examination and vigilant histopathological reporting proves the origin of tumor distant from stomach and thereby change the whole approach of management. PMID:27668229

  6. A rare case of metastatic germ cell tumor to stomach and duodenum masquerading as signet ring cell adenocarcinoma.

    PubMed

    Mazumdar, Srijan; Sundaram, Sridhar; Patil, Prachi; Mehta, Shaesta; Ramadwar, Mukta

    2016-08-01

    Adenocarcinomas are the most common cancers affecting stomach. However gastrointestinal stromal tumors (GIST), lymphomas and neuroendocrine tumors (NETs) can also affect the stomach. But stomach is relatively rare site of involvement by metastasis. In this case report a rare metastasis of germ cell tumor (GCT) into stomach is described which clinically and endoscopically masquerade as primary gastric cancers. But detailed clinical examination and vigilant histopathological reporting proves the origin of tumor distant from stomach and thereby change the whole approach of management. PMID:27668229

  7. Comparison of removal of endodontic smear layer using ethylene glycol bis (beta-amino ethyl ether)-N, N, N', N'-tetraacetic acid and citric acid in primary teeth: A scanning electron microscopic study

    PubMed Central

    Hegde, Rahul J.; Bapna, Kavita

    2016-01-01

    Background: Root canal irrigants are considered momentous in their tissue dissolving property, eliminating microorganisms, and removing smear layer. The present study was aimed to compare the removal of endodontic smear layer using ethylene glycol bis (beta-amino ethyl ether)-N, N, N', N'-tetraacetic acid (EGTA) and citric acid solutions with saline as a control in primary anterior teeth. Materials and Methods: Thirty primary anterior teeth were chosen for the study. The teeth were distributed into three groups having ten teeth each. Following instrumentation, root canals of the first group were treated with 17% EGTA and the second group with 6% citric acid. Only saline was used as an irrigant for the control group. Then, the teeth were subjected to scanning electron microscopy (SEM) study. The scale given by Rome et al. for the smear layer removal was used in the present study. Results: The pictures from the SEM showed that among the tested irrigants, 17% EGTA + 5% sodium hypochlorite (NaOCl) group showed the best results when compared to other groups. Conclusion: The results advocate that the sequential irrigation of the pulp canal walls with 17% EGTA followed by 5% NaOCl produced efficacious and smear-free root canal walls. PMID:27307670

  8. Paraneoplastic tumefactive demyelination with underlying combined germ cell cancer.

    PubMed

    Broadfoot, Jack R; Archer, Hilary A; Coulthard, Elizabeth; Appelman, Auke P A; Sutak, Judit; Braybrooke, Jeremy P; Love, Seth

    2015-12-01

    Paraneoplastic demyelination is a rare disorder of the central nervous system. We describe a 60-year-old man with tumefactive demyelination who had an underlying retroperitoneal germ cell cancer. He presented with visuospatial problems and memory loss and had a visual field defect. His MRI was interpreted as a glioma but stereotactic biopsy showed active demyelination. Investigation for multiple sclerosis was negative but CT imaging showed retroperitoneal lymphadenopathy, and nodal biopsy confirmed a combined germ cell cancer. He responded poorly to corticosteroid treatment, and his visual field defect progressed. However, 6 months after plasma exchange and successful chemotherapy, he has partially improved clinically and radiographically. Tumefactive demyelination is typically associated with multiple sclerosis but may be paraneoplastic. It is important to recognise paraneoplastic tumefactive demyelination early, as the neurological outcome relies on treating the associated malignancy. PMID:26088612

  9. Lifetime stress experience: transgenerational epigenetics and germ cell programming.

    PubMed

    Bale, Tracy L

    2014-09-01

    The transgenerational epigenetic programming involved in the passage of environmental exposures to stressful periods from one generation to the next has been examined in human populations, and mechanistically in animal models. Epidemiological studies suggest that gestational exposures to environmental factors including stress are strongly associated with an increased risk of neurodevelopmental disorders, including attention deficit-hyperactivity disorder, schizophrenia, and autism spectrum disorders. Both maternal and paternal life experiences with stress can be passed on to offspring directly during pregnancy or through epigenetic marks in the germ cell. Animal models of parental stress have examined relevant offspring phenotypes and transgenerational outcomes, and provided unique insight into the germ cell epigenetic changes associated with disruptions in neurodevelopment. Understanding germline susceptibility to exogenous signals during stress exposure and the identification of the types of epigenetic marks is critical for defining mechanisms underlying disease risk.

  10. Mediastinal germ cell tumors: a radiologic-pathologic review.

    PubMed

    Drevelegas, A; Palladas, P; Scordalaki, A

    2001-01-01

    Germ cell tumors of the mediastinum are histologically identical to those found in the testes and ovaries. Early diagnosis and treatment improve the survival rate. Imaging studies of teratoma demonstrate a rounded, often lobulated heterogeneous mass containing soft tissue elements with fluid and fat attenuation. Calcification is present in 20-43% of cases. Seminomas are large masses of homogeneous soft tissue attenuation. Malignant nonseminomatous germ cell tumors are heterogeneous tumors with irregular borders due to invasion of adjacent structures. CT shows the location and extent of the tumors as well as intrinsic elements including soft tissue, fat, fluid, and calcification. CT is the modality of choice for the diagnostic evaluation of these tumors. MRI reveals masses of heterogeneous signal intensity, is more sensitive in depicting infiltration of the adjacent structures by fat plane obliteration, and is performed as an ancillary study.

  11. Glycosylation of RNA polymerase II from wheat germ.

    PubMed

    Cervoni, L; Turano, C; Ferraro, A; Ciavatta, P; Marmocchi, F; Eufemi, M

    1997-11-10

    RNA polymerase II from wheat germ was analyzed for the presence of sugars. The two largest subunits and the 27 and 25 kDa subunits were found to be glycosylated by a variety of sugars. However, no N-acetylglucosamine was detected, which was found by Kelly et al. (J. Biol. Chem. (1993) 268, 10416-10424) in the largest subunit of RNA polymerase II from calf thymus. Thus it appears that the regulatory function of this sugar, postulated by Kelly et al., is performed in the wheat germ enzyme by other monosaccharides. Carbohydrate analysis of the two largest subunits of the calf thymus enzyme also revealed the presence, beside N-acetylglucosamine, of other sugars. Some similarities in the features of glycosylation of the two polymerases, isolated from very different organisms, suggest that the sugar moieties have an important role in the structure and/or function of these enzymes. PMID:9395301

  12. Lifetime stress experience: transgenerational epigenetics and germ cell programming

    PubMed Central

    Bale, Tracy L.

    2014-01-01

    The transgenerational epigenetic programming involved in the passage of environmental exposures to stressful periods from one generation to the next has been examined in human populations, and mechanistically in animal models. Epidemiological studies suggest that gestational exposures to environmental factors including stress are strongly associated with an increased risk of neurodevelopmental disorders, including attention deficit-hyperactivity disorder, schizophrenia, and autism spectrum disorders. Both maternal and paternal life experiences with stress can be passed on to offspring directly during pregnancy or through epigenetic marks in the germ cell. Animal models of parental stress have examined relevant offspring phenotypes and transgenerational outcomes, and provided unique insight into the germ cell epigenetic changes associated with disruptions in neurodevelopment. Understanding germline susceptibility to exogenous signals during stress exposure and the identification of the types of epigenetic marks is critical for defining mechanisms underlying disease risk. PMID:25364281

  13. Germ cell transplantation: a potential treatment of severe testicular failure.

    PubMed

    Cozzolino, D J; Lamb, D J

    2000-12-01

    Although the process of spermatogenesis is relatively efficient and resistant to damage, male infertility can result from exposure to toxic agents such as chemotherapeutic regimes, radiation, or occupational exposures to chemicals. Other types of infertility may result from migratory defects or poor survival of primordial germ cells during development, abnormal repopulation of the tubules by spermatogonia during development, or low cellularity of the testis (hypospermatogenesis). Presently, there are no effective therapies available to treat these patients. Recent studies in animal models have demonstrated that isolated testicular germ cells collected from testes may be transplanted into sterile recipient mice to regenerate spermatogenesis. This technology will have widespread applications in efforts to manipulate the genome and produce transgenic offspring, to improve agricultural species, to enhance sperm production in endangered species, to improve our understanding of the control mechanisms regulating spermatogenesis, and to treat male infertility.

  14. In Search of a Germ Theory Equivalent for Chronic Disease

    PubMed Central

    2012-01-01

    The fight against infectious disease advanced dramatically with the consolidation of the germ theory in the 19th century. This focus on a predominant cause of infections (ie, microbial pathogens) ultimately led to medical and public health advances (eg, immunization, pasteurization, antibiotics). However, the resulting declines in infections in the 20th century were matched by a rise in chronic, noncommunicable diseases, for which there is no single underlying etiology. The discovery of a form of low-grade systemic and chronic inflammation (“metaflammation”), linked to inducers (broadly termed “anthropogens”) associated with modern man-made environments and lifestyles, suggests an underlying basis for chronic disease that could provide a 21st-century equivalent of the germ theory. PMID:22575080

  15. Germ cell tumour: late recurrence after 43 years.

    PubMed

    Mukhtar, S; Beatty, J; Agrawal, S; Christmas, T J; Jameson, C; Huddart, R A

    2011-07-01

    We report the late relapse of a patient following 43 years of surveillance of a germ cell tumour, thought to be a pure seminoma, having undergone yolk sac differentiation. The longest previous recorded time to relapse was 32 years (malignant teratoma with adenocarcinoma de-differentiation).(1) This case report demonstrates a late relapse of a testicular germ cell tumour is possible whatever the initial stage. European Association of Urology guidelines state close and active follow-up is mandatory for at least five years' surveillance due to the high and often late rate of relapse. Furthermore, they also suggest continuing follow-up although it is unclear as to how long this should last.(7)

  16. Spreading of wheat germ agglutinin-induced erythrocyte contact by formation of spatially discrete contacts.

    PubMed

    Darmani, H; Coakley, W T; Hann, A C; Brain, A

    1990-06-01

    The time dependence of agglutination and cell-cell contact spreading in human erythrocytes exposed to wheat germ agglutinin (WGA) was characterized by light and electron microscopy. Cells (3 x 10(7)/mL) had a threshold lectin concentration in the range of 0.6-2.0 micrograms/mL for initial cell contact. Spreading was essentially completed within 60 and 2 min in undisturbed and gently agitated suspensions, respectively. The cells in large WGA agglutinates retained features of their initial disk form in contrast to the convex outlines of polycation or polyethylene glycol-induced agglutinates. Spreading of contact area was accompanied by development of a pattern of discrete contact regions separated by a distance of the order of 1 micron. Freeze fracture electron microscopy and studies with ferritin-labeled WGA showed no significant aggregation of intramembrane particles or specific lectin receptors under conditions when contact spreading occurred. It is argued that flow stress effects on cells in suspended agglutinates give rise to a situation where opposite membranes, at the leading edge of cell contact, are separated by a thin aqueous layer. When this intercellular water layer exceeds a critical length, it becomes unstable. The layer breaks up by surface wave development to form an array of intracellular water spaces. Formation of the aqueous spaces causes opposite membrane regions to move synchronously toward each other. Lectin molecules crosslink the wave crests to give spatially periodic contact points.

  17. Testicular germ cell sensitivity to TRAIL-induced apoptosis is dependent upon p53 expression and is synergistically enhanced by DR5 agonistic antibody treatment.

    PubMed

    McKee, Chad M; Ye, Yang; Richburg, John H

    2006-12-01

    The ability of the TRAIL/DR5 signaling pathway to induce apoptosis has generally been limited to tumor cells. Here we report that in primary testis explants, addition of TRAIL (0.5 mug/ml) caused a three-fold increase in germ cell apoptosis. Furthermore, exposure of C57BL/6 mice to the testicular toxicant, mono-(2-ethylhexyl) phthalate (MEHP), caused an increased p53 stability and elevated DR5 mRNA levels coincident with increases in the levels of apoptosis in spermatocytes. To further assess the mechanisms responsible for the sensitivity of germ cells to undergo TRAIL/DR5-mediated apoptosis, we used the germ cell lines GC-1spg and GC-2spd(ts) (a temperature sensitive spermatocyte-like cell line that allows for p53 nuclear localization at 32 degrees C but not 37 degrees C). Addition of TRAIL and the anti-DR5 monoclonal antibody, MD5-1, triggered a robust synergistic increase of apoptosis in p53 permissive GC-2 cells (32 degrees C) but not in GC-1 cells. In addition, DR5 levels on the plasma membrane of permissive cells were considerably enhanced concomitant with p53 expression and after MD5-1 treatment. These data represent the first indication that testicular germ cells, specifically spermatocytes, can undergo TRAIL-mediated apoptosis and the clinically relevant observation that pretreatment with a DR5 monoclonal antibody can greatly sensitize their apoptotic response to TRAIL.

  18. A rare case of combined placental site trophoblastic tumour with mature cystic teratoma and mixed germ cell tumour in the testis.

    PubMed

    Leow, Wei Qiang; Loh, Hwai Liang Alwin; Lee, Lui Shiong; Goh, Chin Hong Ronald

    2015-08-01

    A 20-year-old male presented with persistent right testicular pain. Following ultrasound detection of testicular nodules and biopsy for intraoperative consultation which yielded germ cell tumour, he underwent radical orchidectomy. A predominantly whitish cyst and a lobulated, variegated nodule were identified. Histology showed a mature cystic teratoma with a focus of infiltrative epithelioid cells containing eosinophilic cytoplasm and pleomorphic nuclei, invading ectatic vessel wall associated with fibrinoid change. These cells were positive for cytokeratin, human placental lactogen and inhibin, while negative for Melan-A, p63 and alpha-fetoprotein, consistent with placental site trophoblastic tumor (PSTT). The variegated nodule was a mixed germ cell tumour composed of embryonal carcinoma and immature teratoma. Aside from choriocarcinoma, primary trophoblastic tumors such as PSTT, which are derived from intermediate trophoblasts, are extremely rare in the testis. Aside from a case of pure testicular PSTT, 2 other cases have been described in association with germ cell tumour, of which one is a mature teratoma with PSTT that demonstrated gain of chromosome 12p. The other presented with PSTT in retroperitoneal recurrence of a testicular mixed germ cell tumour. We discussed the features of this tumour in the testis and important differentials in its diagnosis.

  19. DAZ Family Proteins, Key Players for Germ Cell Development

    PubMed Central

    Fu, Xia-Fei; Cheng, Shun-Feng; Wang, Lin-Qing; Yin, Shen; De Felici, Massimo; Shen, Wei

    2015-01-01

    DAZ family proteins are found almost exclusively in germ cells in distant animal species. Deletion or mutations of their encoding genes usually severely impair either oogenesis or spermatogenesis or both. The family includes Boule (or Boll), Dazl (or Dazla) and DAZ genes. Boule and Dazl are situated on autosomes while DAZ, exclusive of higher primates, is located on the Y chromosome. Deletion of DAZ gene is the most common causes of infertility in humans. These genes, encoding for RNA binding proteins, contain a highly conserved RNA recognition motif and at least one DAZ repeat encoding for a 24 amino acids sequence able to bind other mRNA binding proteins. Basically, Daz family proteins function as adaptors for target mRNA transport and activators of their translation. In some invertebrate species, BOULE protein play a pivotal role in germline specification and a conserved regulatory role in meiosis. Depending on the species, DAZL is expressed in primordial germ cells (PGCs) and/or pre-meiotic and meiotic germ cells of both sexes. Daz is found in fetal gonocytes, spermatogonia and spermatocytes of adult testes. Here we discuss DAZ family genes in a phylogenic perspective, focusing on the common and distinct features of these genes, and their pivotal roles during gametogenesis evolved during evolution. PMID:26327816

  20. Formation and cultivation of medaka primordial germ cells.

    PubMed

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  1. PGC-Enriched miRNAs Control Germ Cell Development

    PubMed Central

    Bhin, Jinhyuk; Jeong, Hoe-Su; Kim, Jong Soo; Shin, Jeong Oh; Hong, Ki Sung; Jung, Han-Sung; Kim, Changhoon; Hwang, Daehee; Kim, Kye-Seong

    2015-01-01

    Non-coding microRNAs (miRNAs) regulate the translation of target messenger RNAs (mRNAs) involved in the growth and development of a variety of cells, including primordial germ cells (PGCs) which play an essential role in germ cell development. However, the target mRNAs and the regulatory networks influenced by miRNAs in PGCs remain unclear. Here, we demonstrate a novel miRNAs control PGC development through targeting mRNAs involved in various cellular pathways. We reveal the PGC-enriched expression patterns of nine miRNAs, including miR-10b, -18a, -93, -106b, -126-3p, -127, -181a, -181b, and -301, using miRNA expression analysis along with mRNA microarray analysis in PGCs, embryonic gonads, and postnatal testes. These miRNAs are highly expressed in PGCs, as demonstrated by Northern blotting, miRNA in situ hybridization assay, and miRNA qPCR analysis. This integrative study utilizing mRNA microarray analysis and miRNA target prediction demonstrates the regulatory networks through which these miRNAs regulate their potential target genes during PGC development. The elucidated networks of miRNAs disclose a coordinated molecular mechanism by which these miRNAs regulate distinct cellular pathways in PGCs that determine germ cell development. PMID:26442865

  2. Development of germ cell neoplasia in situ in chinchilla rabbits.

    PubMed

    Vigueras-Villaseñor, Rosa María; Montelongo Solís, Paola; Chávez-Saldaña, Margarita; Gutiérrez-Pérez, Oscar; Cortés Trujillo, Lucero; Rojas-Castañeda, Julio César

    2016-05-01

    The present study was designed to describe the development of germ cell neoplasia in situ in Chinchilla rabbit by administration of estradiol. The study was performed in rabbits distributed into two groups: control and 17 β-estradiol. The determination of histological alterations and POU5F1 and c-kit proteins employed as biomarkers for the diagnosis of this neoplasia was carried out. Testicular descent and complete spermatogenesis were observed in the control group. The protein biomarkers were negative. However, in the rabbits treated with estradiol, the testes remained undescended with the gonocytes undifferentiated to spermatogonia. There were histological lesions owing to germ cell neoplasia in situ and positive to POU5F1 and c-kit proteins. These findings indicate that the chinchilla rabbit is an ideal model to study this neoplasia in which the histological characteristics and biomarkers of the disease could be clearly observed. Using this model we suggested that the persisting gonocytes could be responsible for the development of germ cell neoplasia in situ. PMID:26617392

  3. NUT protein immunoreactivity in ovarian germ cell tumours.

    PubMed

    Iacobelli, J F; Charles, A K; Crook, M; Stewart, C J R

    2015-02-01

    The aim of this study was to investigate NUT (nuclear protein in the testis) expression in ovarian germ cell tumours (GCTs). Immunostaining for NUT protein was performed in 10 mature cystic teratomas and in 49 malignant ovarian GCTs including 15 pure dysgerminomas, six dysgerminomas associated with gonadoblastoma, nine yolk sac tumours, 12 immature teratomas, and seven mixed malignant tumours. Only nuclear staining was considered a positive finding although cytoplasmic staining was noted when present. Thirty-seven (76%) malignant GCTs were NUT positive but staining was usually of weak to moderate intensity and observed in a relatively small proportion of neoplastic cells. Staining in immature teratomas and yolk sac tumours was restricted to foci of hepatoid and intestinal/glandular differentiation, where both nuclear and cytoplasmic reactivity were observed. In dysgerminoma associated with gonadoblastoma only the in situ and invasive germ cell elements were NUT positive. Nuclear staining was not seen in benign teratomas. Most malignant ovarian GCTs express NUT protein, albeit focally, and this should be considered when evaluating immunostaining in the differential diagnosis of poorly differentiated malignancies, particularly NUT midline carcinoma. Since NUT protein appears to play a role in normal germ cell maturation it may influence intestinal or hepatoid differentiation within malignant GCTs.

  4. Gonadal development and germ cell tumors in mouse and humans.

    PubMed

    Dolci, Susanna; Campolo, Federica; De Felici, Massimo

    2015-09-01

    In multicellular organisms, proper development of gonads and germ cells is essential for the transmission of genetic information to the next generations and eventually for the survival of the species. For this reason, germline development is finely regulated to control germ cell proliferation, survival and differentiation. Disruption of such controls can lead to infertility or germ cell tumors (GCTs). GCTs are particularly hideous pathologies since they occur mainly in neonates, infants, and children, rarely in the adults. They arise primarily in the testes and ovaries, though they can also develop in extragonadal sites along the midline of the body and the brain. Many similarities exist between most types of GCTs of the ovary and testis, including a morphological resemblance (often constituting a caricature of normal embryogenesis) and a similar pattern of chromosomal alterations. Furthermore, families with both ovarian and testicular GCTs have been reported, suggesting a possible common genetic etiology. This review focuses on the cellular processes, differentiation events and molecular mechanisms occurring during gonad development in mice and humans whose disturbance can be implicated in GCT formation.

  5. Prepubertal male rats with high rates of germ-cell apoptosis present exacerbated rates of germ-cell apoptosis after serotonin depletion.

    PubMed

    Méndez Palacios, Néstor; Escobar, María Elena Ayala; Mendoza, Maximino Méndez; Crispín, Rubén Huerta; Andrade, Octavio Guerrero; Melández, Javier Hernández; Martínez, Andrés Aragón

    2016-04-01

    Male germ-cell apoptosis occurs naturally and can be increased by exposure to drugs and toxic chemicals. Individuals may have different rates of apoptosis and are likely to also exhibit differential sensitivity to outside influences. Previously, we reported that p-chloroamphetamine (pCA), a substance that inhibits serotonin synthesis, induced germ-cell apoptosis in prepubertal male rats. Here, we identified prepubertal rats with naturally high or low rates of germ-cell apoptosis and evaluated gene expression in both groups. Bax and Shbg mRNA levels were higher in rats with high rates of germ-cell apoptosis. Rats were then treated with pCA and the neuro-hormonal response and gene expression were evaluated. Treatment with pCA induced a reduction in serotonin concentrations but levels of sex hormones and gonadotrophins were not changed. Rats with initially high rates of germ-cell apoptosis had even higher rates of germ-cell apoptosis after treatment with pCA. In rats with high rates of germ-cell apoptosis Bax mRNA expression remained high after treatment with pCA. On the basis of category, an inverse relationship between mRNA expression of Bax and Bcl2, Bax and AR and Bax and Hsd3b2 was found. Here we provide evidence that innate levels of germ-cell apoptosis could be explained by the level of mRNA expression of genes involved with apoptosis and spermatogenesis.

  6. [One Case about Primary Mediastinal Primary Mediastinal Tumor 
with Mediastinal Sarcoma and Literature Review].

    PubMed

    Du, Jinchen; Li, Qingxin; Chao, Dong; Ban, Yulian; Li, Qunqun

    2016-09-20

    Primary mediastinal seminoma is a kind of germ cell malignancy outside the gonads, and it's rarer with sarcoma component. This disease which has no special clinical manifestations and imaging characteristics is difficult to identify with other mediastinal tumors and mediastinal type lung cancer. This paper reported a case of primary mediastinal seminoma with mediastinal sarcoma. Through the analysis of the diagnosis and treatment process in this patient, we will make a comprehensive review of the disease. PMID:27666557

  7. In Vitro Ectopic Behavior of Porcine Spermatogonial Germ Cells and Testicular Somatic Cells.

    PubMed

    Lee, Kyung Hoon; Lee, Won Young; Do, Jung Tae; Park, Chan Kyu; Kim, Nam Hyung; Kim, Jin Hoi; Chung, Hak Jae; Kim, Dong Woon; Song, Hyuk

    2016-08-01

    Embryonic body-like colony formation is a unique pattern in male germ cell cultures, including spermatogonial stem cells. However, detailed information of the colony formation has not yet been sufficiently reported in male germ cell culture. To elucidate the formation of germ cell-derived colony (GDC), glial cell-derived neurotrophic factor receptor alpha-1 (GFRα-1)-positive pig germ cells were isolated using an immunomagnetic cell isolation method and labeled with red- or green-fluorescent dye. In GDC culture, red-fluorescent-labeled germ cells were evenly distributed in the wells from day 1 to 4, and they clustered together at the time of GDC formation on day 6. Interestingly, feeder cells migrated to the site of colony formation as spermatogonia carriers. Furthermore, when freshly prepared green-labeled GFRα-1-positive germ cells were added, mixed-fluorescent dye (red and green) colonies were observed. On bromodeoxyuridine (BrdU) treatment, 58% ± 3.13% of germ cells were positive to protein gene product 9.5 but negative to BrdU cells. Immunocytochemistry and reverse transcription-polymerase chain reaction results showed that cultured GDC cells were positive to stem cell- and pig germ cell-specific marker genes. In conclusion, in vitro formation of GDCs is mainly dependent on the aggregation of single germ cells as well as on the slow proliferation of germ cells.

  8. Tre1, a G Protein-Coupled Receptor, Directs Transepithelial Migration of Drosophila Germ Cells

    PubMed Central

    2003-01-01

    In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG) is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR), Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target. PMID:14691551

  9. Methods to study maternal regulation of germ cell specification in zebrafish.

    PubMed

    Kaufman, O H; Marlow, F L

    2016-01-01

    The process by which the germ line is specified in the zebrafish embryo is under the control of maternal gene products that were produced during oogenesis. Zebrafish are highly amenable to microscopic observation of the processes governing maternal germ cell specification because early embryos are transparent, and the germ line is specified rapidly (within 4-5h post fertilization). Advantages of zebrafish over other models used to study vertebrate germ cell formation include their genetic tractability, the large numbers of progeny, and the easily manipulable genome, all of which make zebrafish an ideal system for studying the genetic regulators and cellular basis of germ cell formation and maintenance. Classical molecular biology techniques, including expression analysis through in situ hybridization and forward genetic screens, have laid the foundation for our understanding of germ cell development in zebrafish. In this chapter, we discuss some of these classic techniques, as well as recent cutting-edge methodologies that have improved our ability to visualize the process of germ cell specification and differentiation, and the tracking of specific molecules involved in these processes. Additionally, we discuss traditional and novel technologies for manipulating the zebrafish genome to identify new components through loss-of-function studies of putative germ cell regulators. Together with the numerous aforementioned advantages of zebrafish as a genetic model for studying development, we believe these new techniques will continue to advance zebrafish to the forefront for investigation of the molecular regulators of germ cell specification and germ line biology. PMID:27312489

  10. The diversity of nanos expression in echinoderm embryos supports different mechanisms in germ cell specification.

    PubMed

    Fresques, Tara; Swartz, Steven Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M

    2016-07-01

    Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32-128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. PMID:27402572

  11. Methods to study maternal regulation of germ cell specification in zebrafish

    PubMed Central

    Kaufman, O.H.; Marlow, F.L.

    2016-01-01

    The process by which the germ line is specified in the zebrafish embryo is under the control of maternal gene products that were produced during oogenesis. Zebrafish are highly amenable to microscopic observation of the processes governing maternal germ cell specification because early embryos are transparent, and the germ line is specified rapidly (within 4–5 h post fertilization). Advantages of zebrafish over other models used to study vertebrate germ cell formation include their genetic tractability, the large numbers of progeny, and the easily manipulable genome, all of which make zebrafish an ideal system for studying the genetic regulators and cellular basis of germ cell formation and maintenance. Classical molecular biology techniques, including expression analysis through in situ hybridization and forward genetic screens, have laid the foundation for our understanding of germ cell development in zebrafish. In this chapter, we discuss some of these classic techniques, as well as recent cutting-edge methodologies that have improved our ability to visualize the process of germ cell specification and differentiation, and the tracking of specific molecules involved in these processes. Additionally, we discuss traditional and novel technologies for manipulating the zebrafish genome to identify new components through loss-of-function studies of putative germ cell regulators. Together with the numerous aforementioned advantages of zebrafish as a genetic model for studying development, we believe these new techniques will continue to advance zebrafish to the forefront for investigation of the molecular regulators of germ cell specification and germ line biology. PMID:27312489

  12. In Vitro Ectopic Behavior of Porcine Spermatogonial Germ Cells and Testicular Somatic Cells.

    PubMed

    Lee, Kyung Hoon; Lee, Won Young; Do, Jung Tae; Park, Chan Kyu; Kim, Nam Hyung; Kim, Jin Hoi; Chung, Hak Jae; Kim, Dong Woon; Song, Hyuk

    2016-08-01

    Embryonic body-like colony formation is a unique pattern in male germ cell cultures, including spermatogonial stem cells. However, detailed information of the colony formation has not yet been sufficiently reported in male germ cell culture. To elucidate the formation of germ cell-derived colony (GDC), glial cell-derived neurotrophic factor receptor alpha-1 (GFRα-1)-positive pig germ cells were isolated using an immunomagnetic cell isolation method and labeled with red- or green-fluorescent dye. In GDC culture, red-fluorescent-labeled germ cells were evenly distributed in the wells from day 1 to 4, and they clustered together at the time of GDC formation on day 6. Interestingly, feeder cells migrated to the site of colony formation as spermatogonia carriers. Furthermore, when freshly prepared green-labeled GFRα-1-positive germ cells were added, mixed-fluorescent dye (red and green) colonies were observed. On bromodeoxyuridine (BrdU) treatment, 58% ± 3.13% of germ cells were positive to protein gene product 9.5 but negative to BrdU cells. Immunocytochemistry and reverse transcription-polymerase chain reaction results showed that cultured GDC cells were positive to stem cell- and pig germ cell-specific marker genes. In conclusion, in vitro formation of GDCs is mainly dependent on the aggregation of single germ cells as well as on the slow proliferation of germ cells. PMID:27328332

  13. Reevaluation of whether a soma–to–germ-line transformation extends lifespan in Caenorhabditis elegans

    PubMed Central

    Knutson, Andrew Kekūpa'a; Rechtsteiner, Andreas; Strome, Susan

    2016-01-01

    The germ lineage is considered to be immortal. In the quest to extend lifespan, a possible strategy is to drive germ-line traits in somatic cells, to try to confer some of the germ lineage’s immortality on the somatic body. Notably, a study in Caenorhabditis elegans suggested that expression of germ-line genes in the somatic cells of long-lived daf-2 mutants confers some of daf-2’s long lifespan. Specifically, mRNAs encoding components of C. elegans germ granules (P granules) were up-regulated in daf-2 mutant worms, and knockdown of individual P-granule and other germ-line genes in daf-2 young adults modestly reduced their lifespan. We investigated the contribution of a germ-line program to daf-2’s long lifespan and also tested whether other mutants known to express germ-line genes in their somatic cells are long-lived. Our key findings are as follows. (i) We could not detect P-granule proteins in the somatic cells of daf-2 mutants by immunostaining or by expression of a P-granule transgene. (ii) Whole-genome transcript profiling of animals lacking a germ line revealed that germ-line transcripts are not up-regulated in the soma of daf-2 worms compared with the soma of control worms. (iii) Simultaneous removal of multiple P-granule proteins or the entire germ-line program from daf-2 worms did not reduce their lifespan. (iv) Several mutants that robustly express a broad spectrum of germ-line genes in their somatic cells are not long-lived. Together, our findings argue against the hypothesis that acquisition of a germ-cell program in somatic cells increases lifespan and contributes to daf-2’s long lifespan. PMID:26976573

  14. Reevaluation of whether a soma-to-germ-line transformation extends lifespan in Caenorhabditis elegans.

    PubMed

    Knutson, Andrew Kekūpa'a; Rechtsteiner, Andreas; Strome, Susan

    2016-03-29

    The germ lineage is considered to be immortal. In the quest to extend lifespan, a possible strategy is to drive germ-line traits in somatic cells, to try to confer some of the germ lineage's immortality on the somatic body. Notably, a study in Caenorhabditis elegans suggested that expression of germ-line genes in the somatic cells of long-lived daf-2 mutants confers some of daf-2's long lifespan. Specifically, mRNAs encoding components of C. elegans germ granules (P granules) were up-regulated in daf-2 mutant worms, and knockdown of individual P-granule and other germ-line genes in daf-2 young adults modestly reduced their lifespan. We investigated the contribution of a germ-line program to daf-2's long lifespan and also tested whether other mutants known to express germ-line genes in their somatic cells are long-lived. Our key findings are as follows. (i) We could not detect P-granule proteins in the somatic cells of daf-2 mutants by immunostaining or by expression of a P-granule transgene. (ii) Whole-genome transcript profiling of animals lacking a germ line revealed that germ-line transcripts are not up-regulated in the soma of daf-2 worms compared with the soma of control worms. (iii) Simultaneous removal of multiple P-granule proteins or the entire germ-line program from daf-2 worms did not reduce their lifespan. (iv) Several mutants that robustly express a broad spectrum of germ-line genes in their somatic cells are not long-lived. Together, our findings argue against the hypothesis that acquisition of a germ-cell program in somatic cells increases lifespan and contributes to daf-2's long lifespan.

  15. In vitro differentiation of germ cells from stem cells: a comparison between primordial germ cells and in vitro derived primordial germ cell-like cells

    PubMed Central

    Ge, W; Chen, C; De Felici, M; Shen, W

    2015-01-01

    Stem cells are unique cell types capable to proliferate, some of them indefinitely, while maintaining the ability to differentiate into a few or any cell lineages. In 2003, a group headed by Hans R. Schöler reported that oocyte-like cells could be produced from mouse embryonic stem (ES) cells in vitro. After more than 10 years, where have these researches reached? Which are the major successes achieved and the problems still remaining to be solved? Although during the last years, many reviews have been published about these topics, in the present work, we will focus on an aspect that has been little considered so far, namely a strict comparison between the in vitro and in vivo developmental capabilities of the primordial germ cells (PGCs) isolated from the embryo and the PGC-like cells (PGC-LCs) produced in vitro from different types of stem cells in the mouse, the species in which most investigation has been carried out. Actually, the formation and differentiation of PGCs are crucial for both male and female gametogenesis, and the faithful production of PGCs in vitro represents the basis for obtaining functional germ cells. PMID:26469955

  16. Detection of phase specificity of in vivo germ cell mutagens in an in vitro germ cell system.

    PubMed

    Habas, Khaled; Anderson, Diana; Brinkworth, Martin

    2016-04-15

    In vivo tests for male reproductive genotoxicity are time consuming, resource-intensive and their use should be minimised according to the principles of the 3Rs. Accordingly, we investigated the effects in vitro, of a variety of known, phase-specific germ cell mutagens, i.e., pre-meiotic, meiotic, and post-meiotic genotoxins, on rat spermatogenic cell types separated using Staput unit-gravity velocity sedimentation, evaluating DNA damage using the Comet assay. N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU) (spermatogenic phase), 6-mercaptopurine (6-MP) and 5-bromo-2'-deoxy-uridine (5-BrdU) (meiotic phase), methyl methanesulphonate (MMS) and ethyl methanesulphonate (EMS) (post-meiotic phase) were selected for use as they are potent male rodent, germ cell mutagens in vivo. DNA damage was detected directly using the Comet assay and indirectly using the TUNEL assay. Treatment of the isolated cells with ENU and MNU produced the greatest concentration-related increase in DNA damage in spermatogonia. Spermatocytes were most sensitive to 6-MP and 5-BrdU while spermatids were particularly susceptible to MMS and EMS. Increases were found when measuring both Olive tail moment (OTM) and% tail DNA, but the greatest changes were in OTM. Parallel results were found with the TUNEL assay, which showed highly significant, concentration dependent effects of all these genotoxins on spermatogonia, spermatocytes and spermatids in the same way as for DNA damage. The specific effects of these chemicals on different germ cell types matches those produced in vivo. This approach therefore shows potential for use in the detection of male germ cell genotoxicity and could contribute to the reduction of the use of animals in such toxicity assays. PMID:27059372

  17. Generation of exogenous germ cells in the ovaries of sterile NANOS3-null beef cattle

    PubMed Central

    Ideta, Atsushi; Yamashita, Shiro; Seki-Soma, Marie; Yamaguchi, Ryosaku; Chiba, Shiori; Komaki, Haruna; Ito, Tetsuya; Konishi, Masato; Aoyagi, Yoshito; Sendai, Yutaka

    2016-01-01

    Blastocyst complementation (BC) systems have enabled in vivo generation of organs from allogeneic pluripotent cells, compensating for an empty germ cell niche in gene knockout (KO) animals. Here, we succeeded in producing chimeric beef cattle (Wagyu) by transferring allogenic germ cells into ovaries using somatic cell nuclear transfer and BC technology. The KO of NANOS3 (NANOS3−/−) in Wagyu bovine ovaries produced a complete loss of germ cells. Holstein blastomeres (NANOS3+/+) were injected into NANOS3−/− Wagyu embryos. Subsequently, exogenous germ cells (NANOS3+/+) were identified in the NANOS3−/− ovary. These results clearly indicate that allogeneic germ cells can be generated in recipient germ cell-free gonads using cloning and BC technologies. PMID:27117862

  18. Primordial germ cells: the first cell lineage or the last cells standing?

    PubMed Central

    Johnson, Andrew D.; Alberio, Ramiro

    2015-01-01

    Embryos of many animal models express germ line determinants that suppress transcription and mediate early germ line commitment, which occurs before the somatic cell lineages are established. However, not all animals segregate their germ line in this manner. The ‘last cell standing’ model describes primordial germ cell (PGC) development in axolotls, in which PGCs are maintained by an extracellular signalling niche, and germ line commitment occurs after gastrulation. Here, we propose that this ‘stochastic’ mode of PGC specification is conserved in vertebrates, including non-rodent mammals. We postulate that early germ line segregation liberates genetic regulatory networks for somatic development to evolve, and that it therefore emerged repeatedly in the animal kingdom in response to natural selection. PMID:26286941

  19. Generation of exogenous germ cells in the ovaries of sterile NANOS3-null beef cattle.

    PubMed

    Ideta, Atsushi; Yamashita, Shiro; Seki-Soma, Marie; Yamaguchi, Ryosaku; Chiba, Shiori; Komaki, Haruna; Ito, Tetsuya; Konishi, Masato; Aoyagi, Yoshito; Sendai, Yutaka

    2016-01-01

    Blastocyst complementation (BC) systems have enabled in vivo generation of organs from allogeneic pluripotent cells, compensating for an empty germ cell niche in gene knockout (KO) animals. Here, we succeeded in producing chimeric beef cattle (Wagyu) by transferring allogenic germ cells into ovaries using somatic cell nuclear transfer and BC technology. The KO of NANOS3 (NANOS3(-/-)) in Wagyu bovine ovaries produced a complete loss of germ cells. Holstein blastomeres (NANOS3(+/+)) were injected into NANOS3(-/-) Wagyu embryos. Subsequently, exogenous germ cells (NANOS3(+/+)) were identified in the NANOS3(-/-) ovary. These results clearly indicate that allogeneic germ cells can be generated in recipient germ cell-free gonads using cloning and BC technologies. PMID:27117862

  20. Use of Germ-Free Animal Models in Microbiota-Related Research.

    PubMed

    Al-Asmakh, Maha; Zadjali, Fahad

    2015-10-01

    The large intestine is a home for trillions of microbiota, which confer many benefits on the host, including production of vitamins, absorption of nutrients, pathogen displacement, and development of the immune system. For several decades, germ-free animals have been used to study the interaction between the host and its microbiota. This minireview describes the technical aspects for establishing and maintaining germ-free animals and highlights the advantages and disadvantages for germ-free animals as experimental models.

  1. Understanding the Treatment Strategies of Intracranial Germ Cell Tumors: Focusing on Radiotherapy

    PubMed Central

    Park, Jeonghoon

    2015-01-01

    Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients. PMID:26113957

  2. A revised timeline for biological agents: revisiting the early years of the germ theory of disease.

    PubMed

    Rutecki, Gregory W

    2007-01-01

    An agreed upon timeline for the initial, scientifically-informed use of biological agents typically begins with the Japanese Army in Manchuria and China prior to the generalized outbreak of World War II (1932 until 1945). The process included human experimentation with multiple biological agents followed by their release in combat (e.g. the plague bacillus) targeting military personnel and civilians. Two postulates are used support these dates. First, allegations of earlier bacteriological weapon experimentation and/or use represented the accidental, small scale, and sporadic dispersion of infectious agents preceding the Germ Theory of Disease. Therefore, attempts prior to the Twentieth Century were uninformed scientifically and are not considered representative. Later, as the Germ Theory was maturing, the hypothetical timeline was derived, in part retrospectively, from reputable historical sources (the Trillat Report and The League of Nations) published immediately upon the conclusion of World War I. These documents explicitly testified to the total absence of bacteriological weapons in any form (experimentation or battlefield application) directed at human subjects-in stark contrast to the utilization of chemical agents-during the course of that war. Therefore the Japanese Army in Manchuria became time zero. Recently, evidence previously hidden from outside study has surfaced demonstrating that a small group of Turkish physicians injected typhus-contaminated serum into Armenian civilians during WWI. Although controversy persists regarding primary intent-immunization, experimentation on human subjects, or the introduction of a crude biological weapon-the discovery might suggest a revision to the accepted timeline. The primitive efforts with contaminated serum that occurred during the First World War may seem trivial, especially when compared to overall fatalities during that conflict, but they did include the informed and fatal application of microbial agents

  3. Xenogenic oogenesis of chicken (Gallus domesticus) female primordial germ cells in germline chimeric quail (Coturnix japonica) ovary.

    PubMed

    Liu, C H; Chang, I K; Sasse, J; Dumatol, C J; Basker, J V; Wernery, U

    2007-10-01

    In present study, chicken primordial germ cells (PGCs) were transferred into quail embryos to investigate the development of these germ cells in quail ovary. Briefly, 2 microl of chicken embryonic blood (stage 14) or about 100 purified circulating PGCs were transferred into quail embryo. Contribution of chicken PGCs were detected in gonads of chimeric quail embryos (stage 28) by immunocytochemical staining of cell surface antigen SSEA-1, and by in situ hybridization (ISH) with female chicken specific DNA probe. As a result, 52.0+/-43.2 (n=18) and 42.7+/-27.3 (n=17) chicken PGCs were found in the gonads of chimeric quail embryo that was injected with chicken embryonic blood (stage 14) and about 100 purified circulating PGCs, respectively. Furthermore, the ovaries of 81.8% (9/11) 12 days post incubation (dpi) chimeric quail embryos were observed with a mean of 457.6+/-237.1 female chicken PGCs-derived oogonia scattered in ovarian cortex area. In 9 out of 12 newly hatched and one week old chimeric quail chicks, on average of 2883.0+/-1924.1 primary oocytes and 3 follicles derived from chicken PGCs were found, respectively. The present results suggest that chicken female PGCs are able to migrate, colonize, proliferate and differentiate into oogonia, primary oocytes in chimeric quail ovary.

  4. A zebrafish homologue of the chemokine receptor Cxcr4 is a germ-cell guidance receptor

    NASA Astrophysics Data System (ADS)

    Knaut, Holger; Werz, Christian; Geisler, Robert; Tübingen 2000 Screen Consortium; Nüsslein-Volhard, Christiane

    2003-01-01

    Germ cells preserve an individual's genetic information and transmit it to the next generation. Early in development germ cells are set aside and undergo a specialized developmental programme, a hallmark of which is the migration from their site of origin to the future gonad. In Drosophila, several factors have been identified that control germ-cell migration to their target tissues; however, the germ-cell chemoattractant or its receptor have remained unknown. Here we apply genetics and in vivo imaging to show that odysseus, a zebrafish homologue of the G-protein-coupled chemokine receptor Cxcr4, is required specifically in germ cells for their chemotaxis. odysseus mutant germ cells are able to activate the migratory programme, but fail to undergo directed migration towards their target tissue, resulting in randomly dispersed germ cells. SDF-1, the presumptive cognate ligand for Cxcr4, shows a similar loss-of-function phenotype and can recruit germ cells to ectopic sites in the embryo, thus identifying a vertebrate ligand-receptor pair guiding migratory germ cells at all stages of migration towards their target.

  5. Insights into female germ cell biology: from in vivo development to in vitro derivations

    PubMed Central

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

    Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis. PMID:25652637

  6. A new glycosylated dihydrophaseic acid from cacao germs (Theobroma cacao L.).

    PubMed

    Sannohe, Yumiko; Gomi, Shuichi; Murata, Takashi; Ohyama, Makoto; Yonekura, Kumiko; Kanegae, Minoru; Koga, Jinichiro

    2011-01-01

    Cacao beans are composed of cacao nibs and germs. Although numerous chemical and physiological studies on cacao nib compounds have been reported, there is little information on cacao germ compounds. We therefore analyzed an extract from the cacao germ, and found two compounds that were specific to the germ. One of these two compounds was identified as the new glycosylated abscisic acid metabolite, dihydrophaseic acid-4'-O-6″-(β-ribofuranosyl)-β-glucopyranoside, and the other as the known compound, dihydrophaseic acid-4'-O-β-D-glucopyranoside.

  7. Insights into female germ cell biology: from in vivo development to in vitro derivations.

    PubMed

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

    Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis.

  8. Testicular germ cell tumors and related research from a historical point of view.

    PubMed

    Damjanov, Ivan; Wewer-Albrechtsen, Nicolai

    2013-01-01

    In this brief overview of the history of testicular germ cell tumors, we touch upon the key events and personalities that have contributed to our current understanding of germ cell tumors in general, and those of the testis in particular. The intricacies of human germ cell tumor pathology and histogenesis have been elucidated in part by contributions in the field of experimental pathology and developmental biology. Correlation between clinical oncologic findings, pathology and experimental studies of germ cell tumors and related topics ushered the era of cellular and genetic engineering that have revolutionized contemporary cell and molecular biology.

  9. Human somatic cells subjected to genetic induction with six germ line-related factors display meiotic germ cell-like features

    PubMed Central

    Medrano, Jose V.; Martínez-Arroyo, Ana M.; Míguez, Jose M.; Moreno, Inmaculada; Martínez, Sebastián; Quiñonero, Alicia; Díaz-Gimeno, Patricia; Marqués-Marí, Ana I.; Pellicer, Antonio; Remohí, Jose; Simón, Carlos

    2016-01-01

    The in vitro derivation of human germ cells has attracted interest in the last years, but their direct conversion from human somatic cells has not yet been reported. Here we tested the ability of human male somatic cells to directly convert into a meiotic germ cell-like phenotype by inducing them with a combination of selected key germ cell developmental factors. We started with a pool of 12 candidates that were reduced to 6, demonstrating that ectopic expression of the germ line-related genes PRDM1, PRDM14, LIN28A, DAZL, VASA and SYCP3 induced direct conversion of somatic cells (hFSK (46, XY), and hMSC (46, XY)) into a germ cell-like phenotype in vitro. Induced germ cell-like cells showed a marked switch in their transcriptomic profile and expressed several post-meiotic germ line related markers, showed meiotic progression, evidence of epigenetic reprogramming, and approximately 1% were able to complete meiosis as demonstrated by their haploid status and the expression of several post-meiotic markers. Furthermore, xenotransplantation assays demonstrated that a subset of induced cells properly colonize the spermatogonial niche. Knowledge obtained from this work can be used to create in vitro models to study gamete-related diseases in humans. PMID:27112843

  10. Refractory sacrococcygeal germ cell tumor in Schinzel-Giedion syndrome.

    PubMed

    Kishimoto, Kenji; Kobayashi, Ryoji; Yonemaru, Nozomi; Yamamoto, Hiroshi; Tsujioka, Takao; Sano, Hirozumi; Suzuki, Daisuke; Yasuda, Kazue; Suzuki, Masahiko; Ando, Akiko; Tonoki, Hidefumi; Iizuka, Susumu; Uetake, Kimiaki; Kobayashi, Kunihiko

    2015-05-01

    We describe a boy with Schinzel-Giedion syndrome who developed refractory sacrococcygeal germ cell tumor with elements of embryonal carcinoma and immature teratoma. He developed local recurrence soon after tumor resection. The tumor was highly resistant to platinum-based combination chemotherapy, local irradiation, and salvage chemotherapy. Frequent infections resulted in a delay in treatment, although apparent fragility had not been observed clinically. He died from tumor progression at 32 months of age. Intensification of chemotherapy does not seem to be feasible for tumors in patients with Schinzel-Giedion syndrome. PMID:25171454

  11. Gods, Germs, and Petri Dishes: Toward a Nonsecular Medical Anthropology.

    PubMed

    Roberts, Elizabeth F S

    2016-01-01

    This commentary calls on medical anthropology to become programmatically non-secular. Despite recent anthropological critiques of secularity, within and outside of anthropology, most contemporary medical anthropologists continue to leave deities and religiosity out of their examinations of healing practices, especially in their accounts of biomedicine. Through a critical, relational constructionist lens, which traces how all entities are both constructed and real, a non-secular medical anthropology would insist that when deities are part of medical practice, they are integral to analysis. Importantly then, within the symmetrical nature of this same constructionist lens, biomedical entities like germs and petri dishes need to be accounted for just as much as deities.

  12. LINEing germ and embryonic stem cells' silencing of retrotransposons.

    PubMed

    Ishiuchi, Takashi; Torres-Padilla, Maria-Elena

    2014-07-01

    Almost half of our genome is occupied by transposable elements. Although most of them are inactive, one type of non-long terminal repeat (LTR) retrotransposon, long interspersed nuclear element 1 (LINE1), is capable of retrotransposition. Two studies in this issue, Pezic and colleagues (pp. 1410-1428) and Castro-Diaz and colleagues (pp. 1397-1409), provide novel insight into the regulation of LINE1s in human embryonic stem cells and mouse germ cells and shed new light on the conservation of complex mechanisms to ensure silencing of transposable elements in mammals.

  13. Gods, Germs, and Petri Dishes: Toward a Nonsecular Medical Anthropology.

    PubMed

    Roberts, Elizabeth F S

    2016-01-01

    This commentary calls on medical anthropology to become programmatically non-secular. Despite recent anthropological critiques of secularity, within and outside of anthropology, most contemporary medical anthropologists continue to leave deities and religiosity out of their examinations of healing practices, especially in their accounts of biomedicine. Through a critical, relational constructionist lens, which traces how all entities are both constructed and real, a non-secular medical anthropology would insist that when deities are part of medical practice, they are integral to analysis. Importantly then, within the symmetrical nature of this same constructionist lens, biomedical entities like germs and petri dishes need to be accounted for just as much as deities. PMID:26930040

  14. The story of a largely unknown evolution - Germ theory hoax.

    PubMed

    Wainwright, Milton; Alharbi, Sulaiman Ali

    2011-10-01

    The Piltdown Man debacle provides us with the most infamous forgery in science. However, another equally intriguing story exists concerning a document by a Bostonian called George Sleeper, which purported to be a pre-Darwin-Wallace anticipation of evolution and an equally convincing account of the germ theory published before Louis Pasteur's famous studies on this subject. The story involves two giants in the world of evolutionary theory, Alfred Russel Wallace and E.B. Poulton. While Wallace was convinced that the Sleeper document was genuine, Poulton's detailed investigations showed that it was a fake and a hoax. Despite this conclusion, doubts still exist about the authenticity of the Sleeper document.

  15. Mechanisms guiding primordial germ cell migration: strategies from different organisms

    PubMed Central

    Richardson, Brian E.; Lehmann, Ruth

    2015-01-01

    Preface The regulated migration of cells is essential for development and tissue homeostasis, and aberrant cell migration can lead to an impaired immune response and the progression of cancer. Primordial germ cells (PGCs), precursors to sperm and eggs, have to migrate across the embryo to reach somatic gonadal precursors (SGPs) and fulfill their function. Studies of model organisms have revealed that, despite important differences, several features of PGC migration are conserved. PGCs require both an intrinsic motility program and external guidance cues to survive and successfully migrate. Proper guidance involves both attractive and repulsive cues mediated by protein and lipid signalling. PMID:20027186

  16. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    NASA Technical Reports Server (NTRS)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c)< 1 cm/s and v(sub f)> 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  17. Primary mediastinal seminoma. [X ray

    SciTech Connect

    Bush, S.E.; Martinez, A.; Bagshaw, M.A.

    1981-10-15

    Primary mediastinal seminoma is a rare germ cell neoplasm histologically identical to testicular seminoma. Thirteen patients have been treated with definitive megavoltage radiotherapy at the Stanford University Medical Center, Division of Radiation Therapy, between 1961 and 1976. Doses ranged from 2500 rads over five weeks to 6000 rads over seven weeks. Actuarial survival at ten years is 69% with relapse-free survival of 54%. No patient receiving greater than 4700 rads to the primary lesion had local or systemic relapse. Patterns of relapse and recommendations for diagnostic evaluation are discussed. Primary megavoltage irradiation to the mediastinum and neck with a dose of 4500 to 5000 rads over five to six weeks is appropriate treatment.

  18. Pediatric and Adolescent Extracranial Germ Cell Tumors: The Road to Collaboration

    PubMed Central

    Olson, Thomas A.; Murray, Matthew J.; Rodriguez-Galindo, Carlos; Nicholson, James C.; Billmire, Deborah F.; Krailo, Mark D.; Dang, Ha M.; Amatruda, James F.; Thornton, Claire M.; Arul, G. Suren; Stoneham, Sara J.; Pashankar, Farzana; Stark, Daniel; Shaikh, Furqan; Gershenson, David M.; Covens, Allan; Hurteau, Jean; Stenning, Sally P.; Feldman, Darren R.; Grimison, Peter S.; Huddart, Robert A.; Sweeney, Christopher; Powles, Thomas; Lopes, Luiz Fernando; dos Santos Agular, Simone; Chinnaswamy, Girish; Khaleel, Sahar; Abouelnaga, Sherif; Hale, Juliet P.; Frazier, A. Lindsay

    2015-01-01

    During the past 35 years, survival rates for children with extracranial malignant germ cell tumors (GCTs) have increased significantly. Success has been achieved primarily through the application of platinum-based chemotherapy regimens; however, clinical challenges in GCTs remain. Excellent outcomes are not distributed uniformly across the heterogeneous distribution of age, histologic features, and primary tumor site. Despite good outcomes overall, the likelihood of a cure for certain sites and histologic conditions is less than 50%. In addition, there are considerable long-term treatment-related effects for survivors. Even modest cisplatin dosing can cause significant long-term morbidities. A particular challenge in designing new therapies for GCT is that a variety of specialists use different risk stratifications, staging systems, and treatment approaches for three distinct age groups (childhood, adolescence, and young adulthood). Traditionally, pediatric cancer patients younger than 15 years have been treated by pediatric oncologists in collaboration with their surgical specialty colleagues. Adolescents and young adults with GCTs often are treated by medical oncologists, urologists, or gynecologic oncologists. The therapeutic dilemma for all is how to best define disease risk so that therapy and toxicity can be appropriately reduced for some patients and intensified for others. Further clinical and biologic insights can only be achieved through collaborations that do not set limitations by age, sex, and primary tumor site. Therefore, international collaborations, spanning different cooperative groups and disciplines, have been developed to address these challenges. PMID:26304902

  19. Brain Metastases in Patients With Germ Cell Tumors: Prognostic Factors and Treatment Options—An Analysis From the Global Germ Cell Cancer Group

    PubMed Central

    Feldman, Darren R.; Lorch, Anja; Kramar, Andrew; Albany, Costantine; Einhorn, Lawrence H.; Giannatempo, Patrizia; Necchi, Andrea; Flechon, Aude; Boyle, Helen; Chung, Peter; Huddart, Robert A.; Bokemeyer, Carsten; Tryakin, Alexey; Sava, Teodoro; Winquist, Eric William; De Giorgi, Ugo; Aparicio, Jorge; Sweeney, Christopher J.; Cohn Cedermark, Gabriella; Powles, Thomas

    2016-01-01

    Purpose To define characteristics, treatment response, and outcomes of men with brain metastases (BM) from germ cell tumors (GCT). Patients and Methods Data from 523 men with BM from GCT were collected retrospectively from 46 centers in 13 countries by using standardized questionnaires. Clinical features were correlated with overall survival (OS) as the primary end point. Results BM were present at initial diagnosis in 228 men (group A) and at relapse in 295 men (group B). OS at 3 years (3-year OS) was superior in group A versus group B (48% v 27%; P < .001). Multiple BM and the presence of liver or bone metastasis were independent adverse prognostic factors in both groups; primary mediastinal nonseminoma (group A) and elevations of α-fetoprotein of 100 ng/mL or greater or of human chorionic gonadotropin of 5,000 U/L or greater (group B) were additional independent adverse prognostic factors. Depending on these factors, the 3-year OS ranged from 0% to 70% in group A and from 6% to 52% in group B. In group A, 99% of patients received chemotherapy; multimodality treatment or high-dose chemotherapy was not associated with statistically improved survival in multivariable analysis. In group B, only 54% of patients received chemotherapy; multimodality treatment was associated with improved survival compared with single-modality therapy (hazard ratio, 0.51; 95% CI, 0.36 to 0.73; P < .001), as was high-dose compared with conventional-dose chemotherapy (hazard ratio, 0.41; 95% CI, 0.24 to 0.70; P = .001). Conclusion Men with BM from GCT have poor OS, particularly if additional risk factors are present. High-dose chemotherapy and multimodality treatment seemed to improve survival probabilities in men with BM at relapse. PMID:26460295

  20. Spectrum of germ cell tumors: from head to toe.

    PubMed

    Ueno, Teruko; Tanaka, Yumiko Oishi; Nagata, Michio; Tsunoda, Hajime; Anno, Izumi; Ishikawa, Shigemi; Kawai, Koji; Itai, Yuji

    2004-01-01

    Germ cell tumors (GCTs) occur most frequently in the gonads and are relatively rare in other sites, such as the pineal gland, neurohypophysis, mediastinum, and retroperitoneum. GCTs are thought to originate from primordial germ cells, which migrate to the primitive gonadal glands in the urogenital ridge. Extragonadal GCTs might also originate from these cells when the cells are sequestered during their migration. Pathologic subtypes of GCTs vary, and the prevalence of mixed tumors is high. These factors produce a diversity of radiologic findings and make prospective radiologic diagnosis difficult in many cases. However, similar radiologic findings have been observed in pathologically equivalent tumors in varying sites. Seminomas appear as uniformly solid, lobulated masses with fibrovascular septa that enhance intensely. Nonseminomatous GCTs appear as heterogeneous masses with areas of necrosis, hemorrhage, or cystic degeneration. Fat and calcifications are hallmarks of teratomas, most of which are benign. In immature teratomas, scattered fat and calcification within larger solid components are occasionally seen. These imaging characteristics reflect the pathologic features of each tumor, and histologically similar GCTs at varying sites have similar radiologic features. Knowledge of the pathologic appearances of GCTs and their corresponding radiologic appearances will allow radiologists to diagnose these tumors correctly. PMID:15026588

  1. Germ banks affect the inference of past demographic events.

    PubMed

    Živković, Daniel; Tellier, Aurélien

    2012-11-01

    Continuous progress in empirical population genetics based on the whole-genome polymorphism data requires the theoretical analysis of refined models in order to interpret the evolutionary history of populations with adequate accuracy. Recent studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life-history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. Within this study, we investigate the combined effect of germ banking and time-varying population size on the neutral coalescent and particularly derive the allele frequency spectrum under some simplifying assumptions. We then perform an ABC analysis using two simple demographic scenarios-a population expansion and an instantaneous decline. We demonstrate the appreciable influence of seed banks on the estimation of demographic parameters depending on the germination rate with biases scaled by the square of the germination rate. In the more complex case of a population bottleneck, which comprises an instantaneous decline and an expansion phase, ignoring information on the germination rate denies reliable estimates of the bottleneck parameters via the allelic spectrum. In particular, when seeds remain in the bank over several generations, recent expansions may remain invisible in the frequency spectrum, whereas ancient declines leave signatures much longer than in the absence of seed bank.

  2. Controlled nucleation in freeze-drying: effects on pore size in the dried product layer, mass transfer resistance, and primary drying rate.

    PubMed

    Konstantinidis, Alex K; Kuu, Wei; Otten, Lori; Nail, Steven L; Sever, Robert R

    2011-08-01

    A novel and scalable method has been developed to enable control of the ice nucleation step for the freezing process during lyophilization. This method manipulates the chamber pressure of the freeze dryer to simultaneously induce nucleation in all product vials at a desired temperature. The effects of controlled nucleation on the drying rate of various formulations including 5% (w/w) mannitol, 5% (w/w) sucrose, and a mixture of 3% (w/w) mannitol and 2% (w/w) sucrose were studied. For a 5% (w/w) mannitol, uncontrolled ice nucleation occurred randomly at product temperatures between -8.0°C and -15.9°C as the vials were cooled to -40°C. Controlled ice nucleation was achieved at product temperatures between -2.3°C and -3.7°C. The effect of nucleation control on the effective pore radius (r(e) ) of the cake was determined from the product temperature profiles using a pore diffusion model in combination with a nonlinear parameter estimation approach reported earlier. Results show that the value of r(e) for 5% (w/w) mannitol was enlarged from 13 to 27 μm by uniformly inducing nucleation at higher temperatures. Applying the resistance parameters obtained from the pore diffusion model for 5% (w/w) mannitol, optimized cycles were theoretically generated and experimentally tested, resulting in a 41% reduction in primary drying time.

  3. Are There Human Germ-Cell Mutagens? We May Know Soon

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Since then, various rodent-based assays have been used to identify ~50 germ-cell...

  4. On the analysis of neonatal hamster tooth germs with the photon microprobe at Daresbury, UK

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Van Langevelde, F.; Vis, R. D.

    1990-04-01

    Complementary to the micro-PIXE experiments performed on hamster tooth germs to elucidate the role of fluoride during the growth, the photon microprobe at Daresbury was used to obtain information on the distribution of Zn. The germs of fluoride-administered hamsters, together with a control group, were analyzed with the micro-synchrotron radiation fluorescence method (micro-SXRF).

  5. [Auto-transplantation of tooth germs. Discussion and presentation of 3 treated cases].

    PubMed

    Massei, G; Cardesi, E

    1997-01-01

    The authors examine the theoretical possibilities of human dental transplants: autologous, homologous and heterologous. They, then discuss-with reference to autologous transplants-an autotransplant as an alternative to prosthodontic treatment. This would apply both to traditional prosthodontic treatment and on implants or orthodontic treatment aiming at filling dental gaps. They show both general and local counterindications against this operational method the knowledge of which is necessary for an adequate selection of patients. They stress the determining factors for a successful autotransplant: 1) particular care with the choice of the germ to be transplanted taking into account its morphology and the stage of root development; 2) adequate surgical preparation of the receiving site in relation to the size of the germ to be transplanted; 3) suitable surgical technique entailing a particular care in the manipulation of soft and hard tissues and of the germ and appropriate conditions of sterilization; 4) use of appropriate retention means to ensure stability of the transplanted germ so as to favour cellular proliferation and reduce osteoclastic activity; 5) reduction of occlusal pressure on the transplanted germ. The authors describe for example's sake 3 out of 32 cases treated with the documentation of the achieved long-term success. They also analyse the possible causes of failure of such operational method (careless manipulation of the germ, incorrect surgical technique, removal of the germ in a too early stage of its development, too long exposure of the germ outside the oral cavity, poor oral hygiene, caries, periodontal disease, occlusal trauma.

  6. From Young Children's Ideas about Germs to Ideas Shaping a Learning Environment

    ERIC Educational Resources Information Center

    Ergazaki, Marida; Saltapida, Konstantina; Zogza, Vassiliki

    2010-01-01

    This paper is concerned with highlighting young children's ideas about the nature, location and appearance of germs, as well as their reasoning strands about germs' ontological category and biological functions. Moreover, it is concerned with exploring how all these could be taken into account for shaping a potentially fruitful learning…

  7. Ultrastructural and immunocytochemical characterization of ameloblast-enamel adhesion at maturation stage in amelogenesis in Macaca fuscata tooth germ.

    PubMed

    Sawada, Takashi

    2015-12-01

    Maturation-stage ameloblasts are firmly bound to the tooth enamel by a basal lamina-like structure. The mechanism underlying this adhesion, however, remains to be fully clarified. The goal of this study was to investigate the mechanism underlying adhesion between the basal lamina-like structure and the enamel in monkey tooth germ. High-resolution immunogold labeling was performed to localize amelotin and laminin 332 at the interface between ameloblasts and tooth enamel. Minute, electron-dense strands were observed on the enamel side of the lamina densa, extending into the degrading enamel matrix to produce a well-developed fibrous layer (lamina fibroreticularis). In un-demineralized tissue sections, mineral crystals smaller than those in the bulk of the enamel were observed adhering to these strands where they protruded into the surface enamel. Immunogold particles reactive for amelotin were preferentially localized on these strands in the fibrous layer. On the other hand, those for laminin 332 were localized solely in the lamina densa; none were observed in the fibrous layer. These results suggest that the fibrous layer of the basal lamina-like structure is partly composed of amelotin molecules, and that these molecules facilitate ameloblast-enamel adhesion by promoting mineralization of the fibrous layer during the maturation stage of amelogenesis. PMID:26357954

  8. Modeling the Chronic Loss of Optic Nerve Axons and the Effects on the Retinal Nerve Fiber Layer Structure in Primary Disorder of Myelin

    PubMed Central

    Teixeira, Leandro B. C.; Ver Hoeve, James N.; Mayer, Joshua A.; Dubielzig, Richard R.; Smith, Chelsey M.; Radcliff, Abigail B.; Duncan, Ian D.

    2016-01-01

    Purpose We determined whether the chronic lack of optic nerve myelination and subsequent axon loss is associated with optical coherence tomography (OCT) changes in the retinal nerve fiber layer (RNFL), and whether this models what occurs in multiple sclerosis (MS) and confers its use as a surrogate marker for axon degeneration. Methods Using an animal model of Pelizaeus-Merzbacher disease (shp) bilateral longitudinal measurements of the peripapillary RNFL (spectral-domain OCT), electroretinograms (ERG), and visual evoked potentials (VEP) were performed in affected and control animals from 5 months to 2 years and in individual animals at single time points. Light and electron microscopy of the optic nerve and retina and histomorphometric measurements of the RNFL were compared to OCT data. Results Of the shp animals, 17% had an average reduction of OCT RNFL thickness on the superior retinal quadrant compared to controls (P < 0.05). Electroretinograms showed normal photopic A- and B-waves but flash VEPs were disorganized in shp animals. Morphologically, the shp retinas and optic nerves revealed significant RNFL thinning (P < 0.001) without retinal ganglion cell (RGC) loss, decrease total and relative retinal axonal area, and loss of optic nerve axons. There was strong positive correlation between OCT and morphometric RNFL thickness measurements (r = 0.878, P = 0.004). Conclusion The loss of optic nerve axons demonstrated in the shp model resulted in moderate thinning of the RNFL confirmed by OCT and histology. These results indicate that OCT-derived RNFL measurement can be a useful surrogate biomarker of optic nerve axon loss and potentially disease progression in demyelinating diseases. PMID:27654412

  9. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes?

    PubMed

    Taketo, Teruko

    2015-01-01

    The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.

  10. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes?

    PubMed Central

    Taketo, Teruko

    2015-01-01

    The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions. PMID:25578929

  11. A novel gene, Pog, is necessary for primordial germ cell proliferation in the mouse and underlies the germ cell deficient mutation, gcd.

    PubMed

    Agoulnik, Alexander I; Lu, Baisong; Zhu, Qichao; Truong, Cavatina; Ty, Maria T; Arango, Nelson; Chada, Kiran K; Bishop, Colin E

    2002-11-15

    Primordial germ cells (PGCs) are the precursor of the germ cells in adult gonads. They arise extra-gonadally and migrate through somatic tissues to the presumptive genital ridges, where they proliferate and differentiate into oogonia or spermatogonia cells. Abnormalities in this developmental process can cause embryonic depletion of germ cells leading to infertility in the adult. We report here that the mouse gcd (germ cell deficient) mutant phenotype, characterized by reduced numbers of PGCs and adult sterility, is due to reduced PGC proliferation rather than aberrant migration and is caused by the partial deletion of a single novel gene, Pog (proliferation of germ cells). Pog is critical for normal PGC proliferation, starting between 9.5 and 10.25 dpc when germ cells begin to migrate to the developing genital ridge. Deletion of Pog is also accompanied by reduced embryonic body weight and, on some genetic backgrounds, embryonic lethality. Thus, in addition to being necessary for PGC proliferation, Pog may have a wider significance in early embryonic development.

  12. Sexually dimorphic expression of Dmrt1 and γH2AX in germ stem cells during gonadal development in Xenopus laevis.

    PubMed

    Fujitani, Kazuko; Otomo, Asako; Wada, Mikako; Takamatsu, Nobuhiko; Ito, Michihiko

    2016-04-01

    In many animals, primordial germ cells (PGCs) migrate into developing gonads. There, they proliferate and differentiate into female and male germ stem cells (GSCs), oogonia and spermatogonia, respectively. Few studies have focused on the molecular mechanisms underlying the development of GSC sex determination. Here, we investigated the expression of the transcription factor Dmrt1 and a phosphorylated form of the histone variant H2AX (γH2AX) during gonadal development in Xenopus laevis. During early sexual differentiation, Dmrt1 was expressed in the GSCs of the ZW (female) and ZZ (male) gonads as well as somatic cells of the ZZ gonads. Notably, the PGCs and primary GSCs contained large, unstructured nuclei, whereas condensed, rounder nuclei appeared only in primary oogonia during tadpole development. After metamorphosis, Dmrt1 showed its expression in secondary spermatogonia, but not in secondary oogonia. Like Dmrt1, γH2AX was expressed in the nuclei of primary GSCs in early developing gonads. However, after metamorphosis, γH2AX expression continued in primary and secondary spermatogonia, but was barely detected in the condensed nuclei of primary oogonia. Taken together, these observations indicate that spermatogonia tend to retain PGC characteristics, compared to oogonia, which undergo substantial changes during gonadal differentiation in X. laevis. Our findings suggest that Dmrt1 and γH2AX may contribute to the maintenance of stem cell identity by controlling gene expression and epigenetic changes, respectively. PMID:27239441

  13. DAZL Expression Explains Origin and Central Formation of Primordial Germ Cells in Chickens.

    PubMed

    Lee, Hyung Chul; Choi, Hee Jung; Lee, Hyo Gun; Lim, Jeong Mook; Ono, Tamao; Han, Jae Yong

    2016-01-01

    The timing and biological events associated with germ cell specification in chickens have not been determined yet. In this study, we report the origin of primordial germ cells (PGCs) and germ plasm dynamics through investigation of the expression of the chicken homolog of deleted in azoospermia-like (cDAZL) gene during germ cell specification. Asymmetric localization of germ plasm in the center of oocytes from preovulatory follicle stages leads to PGCs being formed in the center. During cleavage stages, DAZL expression pattern changes from a subcellular localization to a diffuse form before and after zygotic genome activation. Meanwhile, PGCs exhibit transcriptional active status during their specification. In addition, knockdown studies of cDAZL, which result in reduced proliferation, aberrant gene expression profiles, and PGC apoptosis in vitro, suggest its possible roles for PGC formation in chicken. In conclusion, DAZL expression reveals formation and initial positioning of PGCs in chickens.

  14. The relevance of spontaneous- and chemically-induced alterations in testicular germ cell apoptosis to toxicology.

    PubMed

    Richburg, J H

    2000-03-15

    Elimination of germ cells via apoptosis occurs spontaneously under normal physiologic conditions and is often heightened after chemical-induced testicular injury. Though many different apoptosis-related elements have been identified in the testis, the molecular and cellular mechanisms that regulate germ cell apoptosis are not thoroughly understood. In this review, the role of germ cell apoptosis in spermatogenesis and possible key regulators of apoptosis is described. The involvement of the Fas-signaling pathway between Sertoli cells and germ cells is highlighted as a crucial paracrine-signaling mechanism that responds to both physiologic- or toxicant-induced declines in the supportive capacity of the testis and reduces the germ cell population accordingly.

  15. Endocrine disrupters, microRNAs, and primordial germ cells: a dangerous cocktail.

    PubMed

    Brieño-Enríquez, Miguel Angel; Larriba, Eduardo; Del Mazo, Jesús

    2016-09-15

    Endocrine-disrupting chemicals (EDCs) are environmental pollutants that may change the homeostasis of the endocrine system, altering the differentiation of germ cells with consequences for reproduction. In mammals, germ cell differentiation begins with primordial germ cells (PGCs) during embryogenesis. Primordial germ cell development and gametogenesis are genetically regulated processes, in which the posttranscriptional gene regulation could be mediated by small noncoding RNAs (sncRNAs) such as microRNAs (miRNAs). Here, we review the deleterious effects of exposure during fetal life to EDCs mediated by deregulation of ncRNAs, and specifically miRNAs on PGC differentiation. Moreover, the environmental stress induced by exposure to some EDCs during the embryonic window of development could trigger reproductive dysfunctions transgenerationally transmitted by epigenetic mechanisms with the involvement of miRNAs expressed in germ line cells. PMID:27521771

  16. The Ter Mutation In The Dead End Gene Causes Germ Cell Loss And Testicular Germ Cell Tumours

    SciTech Connect

    Youngren, Kirsten K.; Coveney, Douglas; Peng, Xiaoning; Bhattacharya, Chitralekha; Schmidt, Laura S.; Nickerson, Michael L.; Lamb, Bruce T.; Deng Jian Min; Behringer, Richard R.; Capel, Blanche; Rubin, Edward M.; Nadeau, Joseph H.; Matin, Angabin

    2005-01-01

    In mice, the Ter mutation causes primordial germ cell (PGC) loss in all genetic backgrounds1. Ter is also a potent modifier of spontaneous testicular germ cell tumour (TGCT) susceptibility in the 129 family of inbred strains, and markedly increases TGCT incidence in 129-Ter/Ter males2 4. In 129-Ter/Ter mice, some of the remaining PGCs transform into undifferentiated pluripotent embryonal carcinoma cells2 6, and after birth differentiate into various cells and tissues that compose TGCTs. Here, we report the positional cloning of Ter, revealing a point mutation that introduces a termination codon in the mouse orthologue (Dnd1) of the zebrafish dead end (dnd) gene. PGC deficiency is corrected both with bacterial artificial chromosomes that contain Dnd1 and with a Dnd1-encoding transgene. Dnd1 is expressed in fetal gonads during the critical period when TGCTs originate. DND1 has an RNA recognition motif and is most similar to the apobec complementation factor, a component of the cytidine t o uridine RNA-editing complex. These results suggest that Ter may adversely affect essential aspects of RNA biology during PGC development. DND1 is the first protein known to have an RNA recognition motif directly implicated as a heritable cause of spontaneous tumorigenesis. TGCT development in the 129-Ter mouse strain models paediatric TGCT in humans. This work will have important implications for our understanding of the genetic control of TGCT pathogenesis and PGC biology.

  17. Ilyanassa Notch signaling implicated in dynamic signaling between all three germ layers.

    PubMed

    Gharbiah, Maey; Nakamoto, Ayaki; Johnson, Adam B; Lambert, J David; Nagy, Lisa M

    2014-01-01

    Two cells (3D and 4d) in the mud snail Ilyanassa obsoleta function to induce proper cell fate. In this study, we provide support for the hypothesis that Notch signaling in Ilyanassa obsoleta functions in inductive signaling at multiple developmental stages. The expression patterns of Notch, Delta and Suppressor of Hairless (SuH) are consistent with a function for Notch signaling in endoderm formation, the function of 3D/4d and the sublineages of 4d. Veligers treated with DAPT show a range of defects that include a loss of endodermal structures, and varying degrees of loss of targets of 4d inductive signaling. Veligers that result from injection of Ilyanassa Delta siRNAi in general mimic the defects observed in the DAPT treated larvae. The most severe DAPT phenotypes mimic early ablations of 4d. However, the early specification of 4d itself appears normal and MAPK activation in both 3D/4d and the micromeres, which are known to activate MAPK as a result of 3D/4d induction, are normal in DAPT treated larvae. Treating larvae at successively later timepoints with DAPT suggests that Notch/Delta signaling is not only required during early 4d inductive signaling, but during subsequent stages of cell fate determination as well. Based on our results, combined with previous reports implicating the endoderm in maintaining induced fate specification in Ilyanassa, we propose a speculative model that Notch signaling is required to specify endoderm fates and 4d sublineages, as well as to maintain cell fates induced by 4d.

  18. From Young Children's Ideas about Germs to Ideas Shaping a Learning Environment

    NASA Astrophysics Data System (ADS)

    Ergazaki, Marida; Saltapida, Konstantina; Zogza, Vassiliki

    2010-11-01

    This paper is concerned with highlighting young children’s ideas about the nature, location and appearance of germs, as well as their reasoning strands about germs’ ontological category and biological functions. Moreover, it is concerned with exploring how all these could be taken into account for shaping a potentially fruitful learning environment. Conducting individual, semi-structured interviews with 35 preschoolers (age 4.5-5.5) of public kindergartens in the broader area of Patras, we attempted to trace their ideas about what germs are, where they may be found, whether they are good or bad and living or non-living and how they might look like in a drawing. Moreover, children were required to attribute a series of biological functions to dogs, chairs and germs, and finally to create a story with germs holding a key-role. The analysis of our qualitative data within the “NVivo” software showed that the informants make a strong association of germs with health and hygiene issues, locate germs mostly in our body and the external environment, are not familiar with the ‘good germs’-idea, and draw germs as ‘human-like’, ‘animal-like’ or ‘abstract’ entities. Moreover, they have significant difficulties not only in employing biological functions as criteria for classifying germs in the category of ‘living’, but also in just attributing such functions to germs using a warrant. Finally, the shift from our findings to a 3-part learning environment aiming at supporting preschoolers in refining their initial conceptualization of germs is thoroughly discussed in the paper.

  19. Melphalan, Carboplatin, Mannitol, and Sodium Thiosulfate in Treating Patients With Recurrent or Progressive CNS Embryonal or Germ Cell Tumors

    ClinicalTrials.gov

    2016-04-28

    Adult Central Nervous System Germ Cell Tumor; Adult Ependymoblastoma; Adult Medulloblastoma; Adult Pineoblastoma; Adult Supratentorial Primitive Neuroectodermal Tumor; Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Ependymoblastoma; Medulloepithelioma; Ototoxicity; Recurrent Adult Brain Neoplasm; Recurrent Childhood Central Nervous System Embryonal Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor

  20. Oil separation from wet milled corn germ dispersions as part of aqueous oil extraction and aqueous enzymatic oil extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oil was obtained from corn germ by aqueous extraction (AE). 100 g batches of germ were mixed with a buffer solution to a mass concentration of 5 to 20% germ, preheated under 2 atm. pressure (120oC), milled in a blender and then churned in an incubator/shaker to coalesce and float oil droplets. The ...

  1. The story of a largely unknown evolution - Germ theory hoax.

    PubMed

    Wainwright, Milton; Alharbi, Sulaiman Ali

    2011-10-01

    The Piltdown Man debacle provides us with the most infamous forgery in science. However, another equally intriguing story exists concerning a document by a Bostonian called George Sleeper, which purported to be a pre-Darwin-Wallace anticipation of evolution and an equally convincing account of the germ theory published before Louis Pasteur's famous studies on this subject. The story involves two giants in the world of evolutionary theory, Alfred Russel Wallace and E.B. Poulton. While Wallace was convinced that the Sleeper document was genuine, Poulton's detailed investigations showed that it was a fake and a hoax. Despite this conclusion, doubts still exist about the authenticity of the Sleeper document. PMID:23961141

  2. Specification and epigenetic programming of the human germ line.

    PubMed

    Tang, Walfred W C; Kobayashi, Toshihiro; Irie, Naoko; Dietmann, Sabine; Surani, M Azim

    2016-10-01

    Primordial germ cells (PGCs), the precursors of sperm and eggs, are established in perigastrulation-stage embryos in mammals. Signals from extra-embryonic tissues induce a unique gene regulatory network in germline-competent cells for PGC specification. This network also initiates comprehensive epigenome resetting, including global DNA demethylation and chromatin reorganization. Mouse germline development has been studied extensively, but the extent to which such knowledge applies to humans was unclear. Here, we review the latest advances in human PGC specification and epigenetic reprogramming. The overall developmental dynamics of human and mouse germline cells appear to be similar, but there are crucial mechanistic differences in PGC specification, reflecting divergence in the regulation of pluripotency and early development. PMID:27573372

  3. Specification and epigenetic programming of the human germ line.

    PubMed

    Tang, Walfred W C; Kobayashi, Toshihiro; Irie, Naoko; Dietmann, Sabine; Surani, M Azim

    2016-10-01

    Primordial germ cells (PGCs), the precursors of sperm and eggs, are established in perigastrulation-stage embryos in mammals. Signals from extra-embryonic tissues induce a unique gene regulatory network in germline-competent cells for PGC specification. This network also initiates comprehensive epigenome resetting, including global DNA demethylation and chromatin reorganization. Mouse germline development has been studied extensively, but the extent to which such knowledge applies to humans was unclear. Here, we review the latest advances in human PGC specification and epigenetic reprogramming. The overall developmental dynamics of human and mouse germline cells appear to be similar, but there are crucial mechanistic differences in PGC specification, reflecting divergence in the regulation of pluripotency and early development.

  4. Development of interspecies testicular germ-cell transplantation in flatfish.

    PubMed

    Pacchiarini, Tiziana; Sarasquete, Carmen; Cabrita, Elsa

    2014-06-01

    Interspecific testicular germ cell (TGC) transplantation was investigated in two commercial flatfish species. Testes from donor species (Senegalese sole) were evaluated using classical histological techniques (haematoxylin-eosin staining and haematoxylin-light green-orange G-acid fuchsine staining), in situ hybridisation and immunohistochemical analysis. Both Ssvasa1-2 mRNAs and SsVasa protein allowed the characterisation of TGCs, confirming the usefulness of the vasa gene in the detection of Senegalese sole TGCs. Xenogenic transplants were carried out using TGCs from one-year-old Senegalese sole into turbot larvae. Propidium iodide-SYBR-14 and 4',6'-diamidino-2-phenylindole (DAPI) staining showed that 87.98% of the extracted testicular cells were viable for microinjection and that 15.63% of the total recovered cells were spermatogonia. The vasa gene was characterised in turbot recipients using cDNA cloning. Smvasa mRNA was confirmed as a germ cell-specific molecular marker in this species. Smvasa expression analysis during turbot ontogeny was carried out before Senegalese sole TGC transplants into turbot larvae. Turbot larvae at 18 days after hatching (DAH) proved to be susceptible to manipulation procedures. High survival rates (83.75±15.90-100%) were obtained for turbot larvae at 27, 34 and 42 DAH. These data highlight the huge potential of this species for transplantation studies. Quantitative PCR was employed to detect Senegalese sole vasa mRNAs (Ssvasa1-2) in the recipient turbot larvae. The Ssvasa mRNAs showed a significant increase in relative expression in 42-DAH microinjected larvae three weeks after treatment, showing the proliferation of Senegalese sole spermatogonia in transplanted turbot larvae.

  5. X-ray micro-analysis of the mineralization patterns in developing enamel in hamster tooth germs exposed to fluoride in vitro during the secretory phase of amelogenesis

    SciTech Connect

    Lyaruu, D.M.; Blijleven, N.; Hoeben-Schornagel, K.; Bronckers, A.L.; Woeltgens, J.H.

    1989-09-01

    The developing enamel from three-day-old hamster first maxillary (M1) molar tooth germs exposed to fluoride (F-) in vitro was analyzed for its mineral content by means of the energy-dispersive x-ray microanalysis technique. The aim of this study was to obtain semi-quantitative data on the F(-)-induced hypermineralization patterns in the enamel and to confirm that the increase in electron density observed in micrographs of F(-)-treated enamel is indeed due to an increase in mineral content in the fluorotic enamel. The tooth germs were explanted during the early stages of secretory amelogenesis and initially cultured for 24 hr in the presence of 10 ppm F- in the culture medium. The germs were then cultured for another 24 hr without F-. In order to compare the ultrastructural results directly with the microprobe data, we used the same specimens for both investigations. The net calcium counts (measurement minus background counts) in the analyses were used as a measure of the mineral content in the enamel. The aprismatic pre-exposure enamel, deposited in vivo before the onset of culture, was the most hypermineralized region in the fluorotic enamel, i.e., it contained the highest amount of calcium measured. The degree of the F(-)-induced hypermineralization gradually decreased (but was not abolished) in the more mature regions of the enamel. The unmineralized enamel matrix secreted during the initial F- treatment in vitro mineralized during the subsequent culture without F-. The calcium content in this enamel layer was in the same order of magnitude as that recorded for the newly deposited enamel in control tooth germs cultured without F-.

  6. Control over the morphology and segregation of Zebrafish germ cell granules during embryonic development

    PubMed Central

    Strasser, Markus J; Mackenzie, Natalia C; Dumstrei, Karin; Nakkrasae, La-Iad; Stebler, Jürg; Raz, Erez

    2008-01-01

    Background Zebrafish germ cells contain granular-like structures, organized around the cell nucleus. These structures share common features with polar granules in Drosophila, germinal granules in Xenopus and chromatoid bodies in mice germ cells, such as the localization of the zebrafish Vasa, Piwi and Nanos proteins, among others. Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development. Results Using transgenic fish expressing a fluorescently labeled novel component of Zebrafish germ cell granules termed Granulito, we followed the morphology and distribution of the granules. We show that whereas these granules initially exhibit a wide size variation, by the end of the first day of development they become a homogeneous population of medium size granules. We investigated this resizing event and demonstrated the role of microtubules and the minus-end microtubule dependent motor protein Dynein in the process. Last, we show that the function of the germ cell granule resident protein the Tudor domain containing protein-7 (Tdrd7) is required for determination of granule morphology and number. Conclusion Our results suggest that Zebrafish germ cell granules undergo a transformation process, which involves germ cell specific proteins as well as the microtubular network. PMID:18507824

  7. Absence of mDazl produces a final block on germ cell development at meiosis.

    PubMed

    Saunders, P T K; Turner, J M A; Ruggiu, M; Taggart, M; Burgoyne, P S; Elliott, D; Cooke, H J

    2003-11-01

    The autosomal gene DAZL is a member of a family of genes (DAZL, DAZ, BOULE), all of which contain a consensus RNA binding domain and are expressed in germ cells. Adult male and female mice null for Dazl lack gametes. In order to define more precisely the developmental stages in germ cells that require Dazl expression, the patterns of germ cell loss in immature male and female wild-type (+/+, WT) and Dazl -/- (DazlKO) mice were analysed. In females, loss of germ cells occurred during fetal life and was coincident with progression of cells through meiotic prophase. In males, testes were recovered from WT and DazlKO males obtained before and during the first wave of spermatogenesis (days 2-19). Mitotically active germ cells were present up to and including day 19. Functional differentiation of spermatogonia associated with detection of c-kit positive cells did not depend upon expression of Dazl. RBMY-positive cells (A, intermediate, B spermatogonia, zygotene and preleptotene spermatocytes) were reduced in DazlKO compared with WT testes. Staining of cell squashes from day 19 testes with anti-gamma-H2AX and anti-SCP3 antibodies showed that germ cells from DazlKO males were unable to progress beyond the leptotene stage of meiotic prophase I. It was concluded that in the absence of Dazl, germ cells can complete mitosis, and embark on functional differentiation but that, in both sexes, progression through meiotic prophase requires this RNA binding protein. PMID:14611631

  8. Radiation-induced bystander signaling from somatic cells to germ cells in Caenorhabditis elegans.

    PubMed

    Guo, Xiaoying; Sun, Jie; Bian, Po; Chen, Lianyun; Zhan, Furu; Wang, Jun; Xu, An; Wang, Yugang; Hei, Tom K; Wu, Lijun

    2013-09-01

    Recently, radiation-induced bystander effects (RIBE) have been studied in mouse models in vivo, which clearly demonstrated bystander effects among somatic cells. However, there is currently no evidence for RIBE between somatic cells and germ cells in animal models in vivo. In the current study, the model animal Caenorhabditis elegans was used to investigate the bystander signaling from somatic cells to germ cells, as well as underlying mechanisms. C. elegans body size allows for precise microbeam irradiation and the abundant mutant strains for genetic dissection relative to currently adopted mouse models make it ideal for such analysis. Our results showed that irradiation of posterior pharynx bulbs and tails of C. elegans enhanced the level of germ cell apoptosis in bystander gonads. The irradiation of posterior pharynx bulbs also increased the level of DNA damage in bystander germ cells and genomic instability in the F1 progeny of irradiated worms, suggesting a potential carcinogenic risk in progeny even only somatic cells of parents are exposed to ionizing radiation (IR). It was also shown that DNA damage-induced germ cell death machinery and MAPK signaling pathways were both involved in the induction of germ cell apoptosis by microbeam induced bystander signaling, indicating a complex cooperation among multiple signaling pathways for bystander effects from somatic cells to germ cells.

  9. Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell.

    PubMed

    Li, Dong; Zuo, Qisheng; Lian, Chao; Zhang, Lei; Shi, Qingqing; Zhang, Zhentao; Wang, Yingjie; Ahmed, Mahmoud F; Tang, Beibei; Xiao, Tianrong; Zhang, Yani; Li, Bichun

    2015-08-01

    We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

  10. Augmented Binary Substitution: Single-pass CDR germ-lining and stabilization of therapeutic antibodies

    PubMed Central

    Townsend, Sue; Fennell, Brian J.; Apgar, James R.; Lambert, Matthew; McDonnell, Barry; Grant, Joanne; Wade, Jason; Franklin, Edward; Foy, Niall; Ní Shúilleabháin, Deirdre; Fields, Conor; Darmanin-Sheehan, Alfredo; King, Amy; Paulsen, Janet E.; Tchistiakova, Lioudmila; Cunningham, Orla; Finlay, William J. J.

    2015-01-01

    Although humanized antibodies have been highly successful in the clinic, all current humanization techniques have potential limitations, such as: reliance on rodent hosts, immunogenicity due to high non-germ-line amino acid content, v-domain destabilization, expression and formulation issues. This study presents a technology that generates stable, soluble, ultrahumanized antibodies via single-step complementarity-determining region (CDR) germ-lining. For three antibodies from three separate key immune host species, binary substitution CDR cassettes were inserted into preferred human frameworks to form libraries in which only the parental or human germ-line destination residue was encoded at each position. The CDR-H3 in each case was also augmented with 1 ± 1 random substitution per clone. Each library was then screened for clones with restored antigen binding capacity. Lead ultrahumanized clones demonstrated high stability, with affinity and specificity equivalent to, or better than, the parental IgG. Critically, this was mainly achieved on germ-line frameworks by simultaneously subtracting up to 19 redundant non-germ-line residues in the CDRs. This process significantly lowered non-germ-line sequence content, minimized immunogenicity risk in the final molecules and provided a heat map for the essential non-germ-line CDR residue content of each antibody. The ABS technology therefore fully optimizes the clinical potential of antibodies from rodents and alternative immune hosts, rendering them indistinguishable from fully human in a simple, single-pass process. PMID:26621728

  11. Essential role of brc-2 in chromosome integrity of germ cells in C. elegans.

    PubMed

    Ko, Eunkyong; Lee, Junho; Lee, Hyunsook

    2008-12-31

    brc-2, an ortholog of BRCA2 in Caenorhabditis elegans, is essential in the maintenance of genetic integrity. In C. elegans, cellular location correlates with meiotic progression, and transgene-induced cosuppression is observed in the germ line but not in somatic cells. We used these unique features to dissect the role of brc-2 in the germ line from that in somatic cells. In situ hybridization of wild type animals revealed that brc-2 gene expression was higher in oocytes than in other germline cells, and was barely detectable in mitotic cells. In contrast, germ cells containing multicopies of the brc-2 transgene showed no significant in situ hybridization signal at any oogenesis stage, confirming that brc-2 expression was functionally cosuppressed in the transgenic germ line. RAD-51 foci formation in response to DNA damage was abrogated in brc-2-cosuppressed germ cells, whereas wild-type germ cells showed strong RAD-51 foci formation. These germ cells exhibited massive chromosome fragmentation and decompaction instead of six bivalent chromosomes in diakinesis. Accordingly, lethality was observed after the early stage of germline development. These results suggest that brc-2 plays essential roles in chromosome integrity in early prophase, and therefore is crucial in meiotic progression and embryonic survival.

  12. The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans

    SciTech Connect

    Ellis, R.; Kimble, J.

    1995-02-01

    In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the same interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two. 68 refs., 7 figs., 6 tabs.

  13. Mechano-logical model of C. elegans germ line suggests feedback on the cell cycle

    PubMed Central

    Atwell, Kathryn; Qin, Zhao; Gavaghan, David; Kugler, Hillel; Hubbard, E. Jane Albert; Osborne, James M.

    2015-01-01

    The Caenorhabditis elegans germ line is an outstanding model system in which to study the control of cell division and differentiation. Although many of the molecules that regulate germ cell proliferation and fate decisions have been identified, how these signals interact with cellular dynamics and physical forces within the gonad remains poorly understood. We therefore developed a dynamic, 3D in silico model of the C. elegans germ line, incorporating both the mechanical interactions between cells and the decision-making processes within cells. Our model successfully reproduces key features of the germ line during development and adulthood, including a reasonable ovulation rate, correct sperm count, and appropriate organization of the germ line into stably maintained zones. The model highlights a previously overlooked way in which germ cell pressure may influence gonadogenesis, and also predicts that adult germ cells might be subject to mechanical feedback on the cell cycle akin to contact inhibition. We provide experimental data consistent with the latter hypothesis. Finally, we present cell trajectories and ancestry recorded over the course of a simulation. The novel approaches and software described here link mechanics and cellular decision-making, and are applicable to modeling other developmental and stem cell systems. PMID:26428008

  14. Apoptotic extinction of germ cells in testes of Cyp26b1 knockout mice.

    PubMed

    MacLean, Glenn; Li, Hui; Metzger, Daniel; Chambon, Pierre; Petkovich, Martin

    2007-10-01

    Cyp26b1 encodes a retinoic acid (RA) metabolizing cytochrome P450 enzyme that is expressed in embryonic tissues undergoing morphogenesis, including the testes. We have generated transgenic mice lacking Cyp26b1 and have observed increased RA levels in embryonic testes. Cyp26b1(-/-) germ cells prematurely enter meiosis at embryonic d 13.5 and appear to arrest at pachytene stage. Furthermore, after embryonic d 13.5, a rapid increase in apoptosis is observed in male germ cells derived from Cyp26b1(-/-) embryos; germ cells are essentially absent in mutant male neonates. In contrast, testicular somatic cells appear to develop normally in the absence of Cyp26b1. Moreover, ovarian germ and somatic cells appear unaffected by the lack of CYP26B1. We also show that the synthetic retinoid Am580, which is resistant to CYP26 metabolism, induces meiosis of male germ cells in cultured gonads, suggesting that abnormal development of germ cells in the Cyp26b1(-/-) testes results from excess RA rather than the absence of CYP26B1-generated metabolites of RA. These results provide evidence that CYP26B1 maintains low levels of RA in the developing testes that blocks entry into meiosis and acts as a survival factor to prevent apoptosis of male germ cells.

  15. Drosophila germ granules are structured and contain homotypic mRNA clusters

    PubMed Central

    Trcek, Tatjana; Grosch, Markus; York, Andrew; Shroff, Hari; Lionnet, Timothée; Lehmann, Ruth

    2015-01-01

    Germ granules, specialized ribonucleoprotein particles, are a hallmark of all germ cells. In Drosophila, an estimated 200 mRNAs are enriched in the germ plasm, and some of these have important, often conserved roles in germ cell formation, specification, survival and migration. How mRNAs are spatially distributed within a germ granule and whether their position defines functional properties is unclear. Here we show, using single-molecule FISH and structured illumination microscopy, a super-resolution approach, that mRNAs are spatially organized within the granule whereas core germ plasm proteins are distributed evenly throughout the granule. Multiple copies of single mRNAs organize into ‘homotypic clusters' that occupy defined positions within the center or periphery of the granule. This organization, which is maintained during embryogenesis and independent of the translational or degradation activity of mRNAs, reveals new regulatory mechanisms for germ plasm mRNAs that may be applicable to other mRNA granules. PMID:26242323

  16. Germs within Worms: Localization of Neorickettsia sp. within Life Cycle Stages of the Digenean Plagiorchis elegans

    PubMed Central

    Greiman, Stephen E.; Rikihisa, Yasuko; Cain, Jacob; Vaughan, Jefferson A.

    2016-01-01

    Neorickettsia spp. are bacterial endosymbionts of parasitic flukes (Digenea) that also have the potential to infect and cause disease (e.g., Sennetsu fever) in the vertebrate hosts of the fluke. One of the largest gaps in our knowledge of Neorickettsia biology is the very limited information available regarding the localization of the bacterial endosymbiont within its digenean host. In this study, we used indirect immunofluorescence microscopy to visualize Neorickettsia sp. within several life cycle stages of the digenean Plagiorchis elegans. Individual sporocysts, cercariae, metacercariae, and adults of P. elegans naturally infected with Neorickettsia sp. were obtained from our laboratory-maintained life cycle, embedded, sectioned, and prepared for indirect immunofluorescence microscopy using anti-Neorickettsia risticii horse serum as the primary antibody. Neorickettsia sp. was found within the tegument of sporocysts, throughout cercarial embryos (germ balls) and fully formed cercariae (within the sporocysts), throughout metacercariae, and within the tegument, parenchyma, vitellaria, uteri, testes, cirrus sacs, and eggs of adults. Interestingly, Neorickettsia sp. was not found within the ovarian tissue. This suggests that vertical transmission of Neorickettsia within adult digeneans occurs via the incorporation of infected vitelline cells into the egg rather than direct infection of the ooplasm of the oocyte, as has been described for other bacterial endosymbionts of invertebrates (e.g., Rickettsia and Wolbachia). PMID:26873314

  17. Germ Tube Mediated Invasion of Batrachochytrium dendrobatidis in Amphibian Skin Is Host Dependent

    PubMed Central

    Van Rooij, Pascale; Martel, An; D'Herde, Katharina; Brutyn, Melanie; Croubels, Siska; Ducatelle, Richard; Haesebrouck, Freddy; Pasmans, Frank

    2012-01-01

    Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines. We focussed on the early stages of infection by Bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. Skin explants of Alytes muletensis, Litoria caerulea and Xenopus leavis were exposed to Bd in an Ussing chamber for 3 to 5 days. Early interactions of Bd with amphibian skin were observed using light microscopy and transmission electron microscopy. To validate the observations in vitro, comparison was made with skin from experimentally infected frogs. Additional in vitro experiments were performed to elucidate the process of intracellular colonization in L. caerulea. Early interactions of Bd with amphibian skin are: attachment of zoospores to host skin, zoospore germination, germ tube development, penetration into skin cells, invasive growth in the host skin, resulting in the loss of host cell cytoplasm. Inoculation of A. muletensis and L. caerulea skin was followed within 24 h by endobiotic development, with sporangia located intracellularly in the skin. Evidence is provided of how intracellular colonization is established and how colonization by Bd proceeds to deeper skin layers. Older thalli develop rhizoid-like structures that spread to deeper skin layers, form a swelling inside the host cell to finally give rise to a new thallus. In X. laevis, interaction of Bd with skin was limited to an epibiotic state, with sporangia developing upon the skin. Only the superficial epidermis was affected. Epidermal cells seemed to be used as a nutrient source without development of intracellular thalli. The in vitro data agreed with the results obtained after experimental infection of the studied frog species. These data suggest that the colonization strategy of B. dendrobatidis is host dependent, with the extent of colonization most likely determined by inherent characteristics of the host

  18. Germ tube mediated invasion of Batrachochytrium dendrobatidis in amphibian skin is host dependent.

    PubMed

    Van Rooij, Pascale; Martel, An; D'Herde, Katharina; Brutyn, Melanie; Croubels, Siska; Ducatelle, Richard; Haesebrouck, Freddy; Pasmans, Frank

    2012-01-01

    Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines.We focussed on the early stages of infection by Bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. Skin explants of Alytes muletensis, Litoria caerulea and Xenopus leavis were exposed to Bd in an Ussing chamber for 3 to 5 days. Early interactions of Bd with amphibian skin were observed using light microscopy and transmission electron microscopy. To validate the observations in vitro, comparison was made with skin from experimentally infected frogs. Additional in vitro experiments were performed to elucidate the process of intracellular colonization in L. caerulea. Early interactions of Bd with amphibian skin are: attachment of zoospores to host skin, zoospore germination, germ tube development, penetration into skin cells, invasive growth in the host skin, resulting in the loss of host cell cytoplasm. Inoculation of A. muletensis and L. caerulea skin was followed within 24 h by endobiotic development, with sporangia located intracellularly in the skin. Evidence is provided of how intracellular colonization is established and how colonization by Bd proceeds to deeper skin layers. Older thalli develop rhizoid-like structures that spread to deeper skin layers, form a swelling inside the host cell to finally give rise to a new thallus. In X. laevis, interaction of Bd with skin was limited to an epibiotic state, with sporangia developing upon the skin. Only the superficial epidermis was affected. Epidermal cells seemed to be used as a nutrient source without development of intracellular thalli. The in vitro data agreed with the results obtained after experimental infection of the studied frog species. These data suggest that the colonization strategy of B. dendrobatidis is host dependent, with the extent of colonization most likely determined by inherent characteristics of the host

  19. Determination of enamel protein synthesized by recombined mouse molar tooth germs in organ culture.

    PubMed

    Baba, T; Terashima, T; Oida, S; Sasaki, S

    1996-02-01

    Epithelial-mesenchymal interaction is a prerequisite for tooth morphogenesis. To study this interaction, inner enamel epithelium and dental papilla mesenchyme of molar tooth germs from a 16.5-day mouse embryo were dissociated enzymatically and cultured alone or after recombination. Characteristic matrix protein synthesized and secreted by recombined tooth germ was determined quantitatively by enzyme-linked immunosorbent assay. The protein was detected in the culture of recombined tooth germ but not of dissociated enamel epithelium alone. The amount of enamel protein increased until 8 days in culture. Morphological differentiation of the recombined epithelial rudiment into ameloblasts and enamel protein production were confirmed.

  20. Chemotherapy for Good-Risk Nonseminomatous Germ Cell Tumors: Current Concepts and Controversies.

    PubMed

    In, Gino; Dorff, Tanya

    2015-08-01

    The rate of diagnosis of germ cell tumors has remained fairly constant. By the International Germ Cell Cancer Consensus Classification, roughly 60% of all metastatic germ cell tumors are classified as good risk. This group of patients has an excellent prognosis, with greater than 90% expectation of cure. Treatment standards have not changed much in recent years. This article focuses on key concepts in the development of the currently accepted first-line regimens and addresses some evolving areas of interest, if not controversy. PMID:26216822

  1. Atypical presentation of pediatric mixed germ cell tumors in the sellar-suprasellar region.

    PubMed

    Furtado, Sunil V; Thakar, Sumit; Ghosal, Nandita; Hegde, Alangar S

    2012-01-01

    Intracranial germ cell tumors constitute a unique group of tumors, more often reported from the Asian region. Amongst them, the non-germinomatous variety occurs with a lesser frequency than the germinomatous variety. We report two children with mixed germ cell tumors with unusual clinical presentations: Central diabetes insipidus and recent-onset oculomotor palsy mimicking pituitary apoplexy. Unlike in adults, suprasellar lesions with a pituitary apoplexy-like picture in the pediatric age group may suggest a possibility of a mixed germ cell tumor. PMID:22406789

  2. Primary yolk sac tumor of the gluteus: a case report and literature review

    PubMed Central

    Li, Bo; Jiang, Qianqian; Zhang, Shitai; Zhou, Yang; Zhang, Qing-Fu; OuYang, Ling

    2016-01-01

    Yolk sac tumor (YST) is a common malignant primitive germ cell tumor that often exhibits differentiation into endodermal structures. They most commonly occur in childhood and adolescence and are rare after the age of 40 years. Derived from the yolk sac during the embryonic period, YSTs can occur in the gonads and germ cells because the tumor cells migrate from the yolk sac toward the gonads. Here, we present a rare case of primary gluteus YST in a 3-year-old girl. She received BEP chemotherapy (bleomycin + etoposide + cisplatin) after surgical resection. There was no evidence of recurrence 7 months after primary treatment. PMID:27536133

  3. Primary yolk sac tumor of the gluteus: a case report and literature review.

    PubMed

    Li, Bo; Jiang, Qianqian; Zhang, Shitai; Zhou, Yang; Zhang, Qing-Fu; OuYang, Ling

    2016-01-01

    Yolk sac tumor (YST) is a common malignant primitive germ cell tumor that often exhibits differentiation into endodermal structures. They most commonly occur in childhood and adolescence and are rare after the age of 40 years. Derived from the yolk sac during the embryonic period, YSTs can occur in the gonads and germ cells because the tumor cells migrate from the yolk sac toward the gonads. Here, we present a rare case of primary gluteus YST in a 3-year-old girl. She received BEP chemotherapy (bleomycin + etoposide + cisplatin) after surgical resection. There was no evidence of recurrence 7 months after primary treatment. PMID:27536133

  4. Long-term follow-up of residual masses after chemotherapy in patients with non-seminomatous germ cell tumours.

    PubMed

    Napier, M P; Naraghi, A; Christmas, T J; Rustin, G J

    2000-11-01

    This retrospective study was undertaken to determine the outcome of patients with non-seminomatous germ cell tumour who achieved a serological complete response but who had residual radiologic abnormalities upon completion of primary platinum-based chemotherapy. This was an analysis of 76 consecutive patients treated at Mount Vernon Hospital between 1983 and 1997. The patients were placed into two groups based upon whether they had surgical resection (surgery group, 48 patients) or observation (observation group, 28 patients) of residual radiologic masses on completion of initial chemotherapy (to enter the surgery group, complete surgical resection must have been achieved). The primary end-points were progression-free and overall survival. The percentage of patients alive with median follow-up 66 months was 90% for the surgery group and 80% for the observation group (P = 0.53, not significant). The percentage of patients continuously disease-free was 70% in the surgery group and 80% in the observation group (P = 0.31, not significant). In the small sub-group of patients with differentiated teratoma (TD) in the primary lesion who were observed, there was no excess risk of relapse or death. Patients who achieve a serological complete response after primary chemotherapy, but are left with

  5. Human endogenous retrovirus rec interferes with germ cell development in mice and may cause carcinoma in situ, the predecessor lesion of germ cell tumors.

    PubMed

    Galli, Uwe M; Sauter, Marlies; Lecher, Bernd; Maurer, Simone; Herbst, Hermann; Roemer, Klaus; Mueller-Lantzsch, Nikolaus

    2005-04-28

    Germ cell tumors (GCTs) are among the most common malignancies in young men. We have previously documented that patients with GCT frequently produce serum antibodies directed against proteins encoded by human endogenous retrovirus (HERV) type K sequences. Transcripts originating from the env gene of HERV-K, including the rec-relative of human immunodeficiency virus rev, are highly expressed in GCTs. We report here that mice that inducibly express HERV-K rec show a disturbed germ cell development and may exhibit, by 19 months of age, changes reminiscent of carcinoma in situ, the predecessor lesion of classic seminoma in humans. This provides the first direct evidence that the expression of a human endogenous retroviral gene previously established as a marker in human germ cell tumors may contribute to organ-specific tumorigenesis in a transgenic mouse model.

  6. Mouse oocytes differentiate through organelle enrichment from sister cyst germ cells.

    PubMed

    Lei, Lei; Spradling, Allan C

    2016-04-01

    Oocytes differentiate in diverse species by receiving organelles and cytoplasm from sister germ cells while joined in germline cysts or syncytia. Mouse primordial germ cells form germline cysts, but the role of cysts in oogenesis is unknown. We find that mouse germ cells receive organelles from neighboring cyst cells and build a Balbiani body to become oocytes, whereas nurselike germ cells die. Organelle movement, Balbiani body formation, and oocyte fate determination are selectively blocked by low levels of microtubule-dependent transport inhibitors. Membrane breakdown within the cyst and an apoptosis-like process are associated with organelle transfer into the oocyte, events reminiscent of nurse cell dumping in Drosophila We propose that cytoplasmic and organelle transport plays an evolutionarily conserved and functionally important role in mammalian oocyte differentiation.

  7. [Current progress and future direction in the biology of ovarian germ stem cells in mammals].

    PubMed

    Li, Chao-Hui; Guo, Kun; Zheng, Ping

    2012-12-01

    Whether or not oogenesis continues after birth in mammalian ovaries remains controversial. Since the 1950's, it has been generally accepted that oogenesis takes place during embryogenesis in mammals and ceases at birth. At birth, germ cells in mammalian ovaries have progressed to the diplotene stage of meiotic prophase and have formed primordial follicles with surrounding somatic cells. These primordial follicles represent follicle reserves of the reproductive life. However, this view has been recently challenged by a growing body of evidence showing the isolation and propagation of germ stem cells from mouse and human ovaries. These ovarian germ stem cells are capable of regenerating functional oocytes when transplanted back into recipient ovaries. Despite the discovery of the potential germ stem cells in mammalian ovaries, it remains uncertain whether these cells exist and function in ovaries under physiological conditions. Herein we review the current progress and future direction in this infant area.

  8. CDC Vital Signs: Making Health Care Safer -- Stop Infections from Lethal CRE Germs Now

    MedlinePlus

    ... 62 MB] Read the MMWR Science Clips Making Health Care Safer Stop Infections from Lethal CRE Germs Now ... to otherwise healthy people outside of medical facilities. Health Care Providers can Know if patients in your facility ...

  9. Mouse oocytes differentiate through organelle enrichment from sister cyst germ cells.

    PubMed

    Lei, Lei; Spradling, Allan C

    2016-04-01

    Oocytes differentiate in diverse species by receiving organelles and cytoplasm from sister germ cells while joined in germline cysts or syncytia. Mouse primordial germ cells form germline cysts, but the role of cysts in oogenesis is unknown. We find that mouse germ cells receive organelles from neighboring cyst cells and build a Balbiani body to become oocytes, whereas nurselike germ cells die. Organelle movement, Balbiani body formation, and oocyte fate determination are selectively blocked by low levels of microtubule-dependent transport inhibitors. Membrane breakdown within the cyst and an apoptosis-like process are associated with organelle transfer into the oocyte, events reminiscent of nurse cell dumping in Drosophila We propose that cytoplasmic and organelle transport plays an evolutionarily conserved and functionally important role in mammalian oocyte differentiation. PMID:26917595

  10. Ounce of Prevention Keeps the Germs Away: Seven Keys to a Safer Healthier Home

    MedlinePlus

    ... actually destroy bacteria and other germs. Check the product label to make sure it says “Disinfectant” and has ... meat and poultry). • Follow all directions on the product label, which usually specifies letting the disinfectant stand for ...

  11. Refuting the hypothesis that the acquisition of germ plasm accelerates animal evolution

    PubMed Central

    Whittle, Carrie A.; Extavour, Cassandra G.

    2016-01-01

    Primordial germ cells (PGCs) give rise to the germ line in animals. PGCs are specified during embryogenesis either by an ancestral mechanism of cell–cell signalling (induction) or by a derived mechanism of maternally provided germ plasm (preformation). Recently, a hypothesis was set forth purporting that germ plasm liberates selective constraint and accelerates an organism's protein sequence evolution, especially for genes from early developmental stages, thereby leading to animal species radiations; empirical validation has been claimed in vertebrates. Here we present findings from global rates of protein evolution in vertebrates and invertebrates refuting this hypothesis. Contrary to assertions of the hypothesis, we find no effect of preformation on protein sequence evolution, the evolutionary rates of early-stage developmental genes, or on species diversification. We conclude that the hypothesis is mechanistically implausible, and our multi-faceted analysis shows no empirical support for any of its predictions. PMID:27577604

  12. Avoiding bad genes: oxidatively damaged DNA in germ line and mate choice.

    PubMed

    Velando, Alberto; Torres, Roxana; Alonso-Alvarez, Carlos

    2008-11-01

    August Weismann proposed that genetic changes in somatic cells cannot pass to germ cells and hence to next generations. Nevertheless, evidence is accumulating that some environmental effects can promote heritable changes in the DNA of germ cells, which implies that some somatic influence on germ line is possible. This influence is mostly detrimental and related to the presence of oxidative stress, which induces mutations and epigenetic changes. This effect should be stronger in males due to the particular characteristics of sperm. Here, we propose the hypothesis that females are able to avoid males with oxidatively damaged DNA in the germ line by using oxidative-dependent (pre- and post-mating) signals. This new hypothesis may shed light on unsolved questions in evolutionary biology, such as the benefits of polyandry, the lek paradox, or the role of sexual selection on the evolution of aging. PMID:18937375

  13. Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field

    PubMed Central

    Yamamoto, Naomi; Oshima, Masamitsu; Tanaka, Chie; Ogawa, Miho; Nakajima, Kei; Ishida, Kentaro; Moriyama, Keiji; Tsuji, Takashi

    2015-01-01

    The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force. PMID:26673152

  14. Analysis of Maize Seed Germs by Photoacoustic Microscopy and Photopyroelectric Technique

    NASA Astrophysics Data System (ADS)

    Pacheco, A. Domínguez; Aguilar, C. Hernández; Cruz-Orea, A.

    2013-05-01

    A knowledge about thermal parameters of structural components of maize seed is of great relevance in the seed technology practice. The objective of the present study was to determine the thermal effusivity of germs of maize ( Zea mays L.) of different genotypes by means of the photopyroelectric technique (PPE) in the inverse configuration and obtaining the thermal imaging of these samples by photoacoustic microscopy (PAM). Germs from crystalline maize (white pigment), semi-crystalline maize (yellow pigment), and floury maize (blue pigment) were used in this investigation. The results show differences between germs of maize seeds mainly in the values of their thermal effusivities. The thermal images showed minimum inhomogeneity of these seed germs. Characterizations of thermal parameters in seeds are important in agriculture and food production and could be particularly useful to define their quality and determine their utility. PPE and PAM can be considered as potential diagnostic tools for the characterization of agriculture seeds.

  15. Examination of plants in lunar (germ free) soil in Plant Laboratory

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Dr. Charles Walkenshaw, Manned Spacecraft Center botanist, examines sorghum and tobacco plants in lunar (germ free) soil in the Plant Laboratory of the Lunar Receiving Laboratory. The soil was brought back from the Moon by the Apollo 11 astronauts.

  16. Mammalian male germ cells are fertile ground for expression profiling of sexual reproduction.

    PubMed

    Wrobel, Gunnar; Primig, Michael

    2005-01-01

    Recent large-scale transcriptional profiling experiments of mammalian spermatogenesis using rodent model systems and different types of microarrays have yielded insight into the expression program of male germ cells. These studies revealed that an astonishingly large number of loci are differentially expressed during spermatogenesis. Among them are several hundred transcripts that appear to be specific for meiotic and post-meiotic germ cells. This group includes many genes that were previously implicated in spermatogenesis and/or fertility and others that are as yet poorly characterized. Profiling experiments thus reveal candidates for regulation of spermatogenesis and fertility as well as targets for innovative contraceptives that act on gene products absent in somatic tissues. In this review, consolidated high density oligonucleotide microarray data from rodent total testis and purified germ cell samples are analyzed and their impact on our understanding of the transcriptional program governing male germ cell differentiation is discussed. PMID:15615893

  17. Refuting the hypothesis that the acquisition of germ plasm accelerates animal evolution.

    PubMed

    Whittle, Carrie A; Extavour, Cassandra G

    2016-01-01

    Primordial germ cells (PGCs) give rise to the germ line in animals. PGCs are specified during embryogenesis either by an ancestral mechanism of cell-cell signalling (induction) or by a derived mechanism of maternally provided germ plasm (preformation). Recently, a hypothesis was set forth purporting that germ plasm liberates selective constraint and accelerates an organism's protein sequence evolution, especially for genes from early developmental stages, thereby leading to animal species radiations; empirical validation has been claimed in vertebrates. Here we present findings from global rates of protein evolution in vertebrates and invertebrates refuting this hypothesis. Contrary to assertions of the hypothesis, we find no effect of preformation on protein sequence evolution, the evolutionary rates of early-stage developmental genes, or on species diversification. We conclude that the hypothesis is mechanistically implausible, and our multi-faceted analysis shows no empirical support for any of its predictions. PMID:27577604

  18. Germ-cell deficient (gcd), an insertional mutation manifested as infertility in transgenic mice.

    PubMed

    Pellas, T C; Ramachandran, B; Duncan, M; Pan, S S; Marone, M; Chada, K

    1991-10-01

    A genetic analysis is necessary to gain a greater understanding of the complex developmental processes in mammals. Toward this end, an insertional transgenic mouse mutant has been isolated that results in abnormal germ-cell development. This recessive mutation manifests as infertility in both males and females and is specific for the reproductive organs, since all other tissues examined were histologically normal. A developmental analysis of the gonadal tissues demonstrated that the germ cells were specifically depleted as early as day 11.5 of embryonic development, while the various somatic cells were apparently unaffected. Therefore, the mutated locus must play a critical role in the migration/proliferation of primordial germ cells to the genital ridges of developing embryos. In addition, females homozygous for the mutation could potentially be a valuable animal model of a human syndrome, premature ovarian failure. This mutation has been named germ-cell deficient, gcd.

  19. Modeling cell elongation during germ band retraction: cell autonomy versus applied anisotropic stress

    NASA Astrophysics Data System (ADS)

    Lynch, Holley E.; Veldhuis, Jim; Brodland, G. Wayne; Hutson, M. Shane

    2014-05-01

    The morphogenetic process of germ band retraction in Drosophila embryos involves coordinated movements of two epithelial tissues—germ band and amnioserosa. The germ band shortens along its rostral-caudal or head-to-tail axis, widens along its perpendicular dorsal-ventral axis, and uncurls from an initial ‘U’ shape. The amnioserosa mechanically assists this process by pulling on the crook of the U-shaped germ band. The amnioserosa may also provide biochemical signals that drive germ band cells to change shape in a mechanically autonomous fashion. Here, we use a finite-element model to investigate how these two contributions reshape the germ band. We do so by modeling the response to laser-induced wounds in each of the germ band’s spatially distinct segments (T1-T3, A1-A9) during the middle of retraction when segments T1-A3 form the ventral arm of the ‘U’, A4-A7 form its crook, and A8-A9 complete the dorsal arm. We explore these responses under a range of externally applied stresses and internal anisotropy of cell edge tensions—akin to a planar cell polarity that can drive elongation of cells in a direction parallel to the minimum edge tension—and identify regions of parameter space (edge-tension anisotropy versus stress anisotropy) that best match previous experiments for each germ band segment. All but three germ band segments are best fit when the applied stress anisotropy and the edge-tension anisotropy work against one another—i.e., when the isolated effects would elongate cells in perpendicular directions. Segments in the crook of the germ band (A4-A7) have cells that elongate in the direction of maximum external stress, i.e., external stress anisotropy is dominant. In most other segments, the dominant factor is internal edge-tension anisotropy. These results are consistent with models in which the amnioserosa pulls on the crook of the germ band to mechanically assist retraction. In addition, they suggest a mechanical cue for edge

  20. Progesterone regulates chicken embryonic germ cell meiotic initiation independent of retinoic acid signaling.

    PubMed

    Mi, Yuling; He, Bin; Li, Jian; Zhang, Caiqiao

    2014-07-15

    The signaling molecule retinoic acid (RA) is known to trigger germ cells to enter meiosis. However, RA may not be the only secreted inducer of meiosis. Our previous data indicate that luteinizing hormone also promotes germ cell meiotic initiation by upregulating 3βHSDII transcription. Here, using chicken embryos, we investigate the role of progesterone (P4) in regulating germ cell meiotic initiation. Progesterone treatment at embryonic Day 9.5 accelerated germ cell meiosis entry in the female chicken embryos. However, P4 treatment in vivo did no influence on testicular germ cells but triggered their meiotic initiation in the cultured testes. As treatment with an RA receptor (RAR) inhibitor did not block the stimulatory effect of P4 on germ cell meiotic initiation, this P4 stimulatory effect seems to be independent of RAR-mediated signaling. The abundance of RA metabolism-related enzymes and RAR (RARβ) mRNAs did not differ significantly between P4-treated and control individuals. The RA concentration in the ovaries remained unchanged by P4 treatment in vivo. Because no inhibition by the P4 receptor (PR) nuclear receptor antagonist mifepristone on P4 effect was observed in either in vitro or in vivo experiments, the effect of P4 on germ cell meiotic initiation is probably mediated by membrane PRs (mPR). The mPRα, mPRβ, and mPRγ mRNAs were all expressed in the embryonic ovaries. The expression of mPRα and mPRβ was higher than that of mPRγ. Immunohistochemical results showed that mPRα-positive cells were mainly scattered in the ovarian cortex area where most germ cells were distributed. The mPRβ-positive cells were widely distributed in the ovaries, and positive cells were clustered with a similar morphology to that of germ cell clusters. In conclusion, P4 may regulate embryonic germ cell meiotic initiation independent of RA signaling through the membrane PRs. This study provides a new insight into the mechanisms of germ cell meiotic initiation in the chicken

  1. Multidimensional representations: The knowledge domain of germs held by students, teachers and medical professionals

    NASA Astrophysics Data System (ADS)

    Rua, Melissa Jo

    The present study examined the understandings held by 5th, 8th, and 11th-grade students, their teachers and medical professionals about germs. Specifically, this study describes the content and structure of students' and adults' conceptions in the areas of germ contraction, transmission, and treatment of infectious and non-infectious diseases caused by microorganisms. Naturalistic and empirical research methods were used to investigate participants' conceptions. Between and within group similarities were found using data from concept maps on the topic "flu," drawings of germs, a 20 word card sort related to germs and illness, and a semi-structured interview. Concept maps were coded according to techniques by Novak and Gowan (1984). Drawings of germs were coded into four main categories (bacteria, viruses, animal cell, other) and five subcategories (disease, caricature, insect, protozoa, unclassified). Cluster patterns for the card sorts of each group were found using multidimensional scaling techniques. Six coding categories emerged from the interview transcripts: (a) transmission, (b) treatment, (c) effect of weather on illness, (d) immune response, (e) location of germs, and (f) similarities and differences between bacteria and viruses. The findings showed students, teachers and medical professionals have different understandings about bacteria and viruses and the structures of those understandings vary. Gaps or holes in the participants knowledge were found in areas such as: (a) how germs are transmitted, (b) where germs are found, (c) how the body transports and uses medicine, (d) how the immune system functions, (e) the difference between vaccines and non-prescription medicines, (f) differences that exist between bacteria and viruses, and (g) bacterial resistance to medication. The youngest students relied heavily upon personal experiences with germs rather than formal instruction when explaining their conceptions. As a result, the influence of media was

  2. Modeling cell elongation during germ band retraction: cell autonomy versus applied anisotropic stress

    PubMed Central

    Lynch, Holley E.; Veldhuis, Jim; Brodland, G. Wayne; Hutson, M. Shane

    2014-01-01

    The morphogenetic process of germ band retraction in Drosophila embryos involves coordinated movements of two epithelial tissues – germ band and amnioserosa. The germ band shortens along its rostral-caudal or head-to-tail axis, widens along its perpendicular dorsal-ventral axis, and uncurls from an initial ‘U’ shape. The amnioserosa mechanically assists this process by pulling on the crook of the U-shaped germ band. The amnioserosa may also provide biochemical signals that drive germ band cells to change shape in a mechanically autonomous fashion. Here, we use a finite-element model to investigate how these two contributions reshape the germ band. We do so by modeling the response to laser-induced wounds in each of the germ band’s spatially distinct segments (T1-T3, A1-A9) during the middle of retraction when segments T1-A3 form the ventral arm of the ‘U’, A4-A7 form its crook, and A8-A9 complete the dorsal arm. We explore these responses under a range of externally applied stresses and internal anisotropy of cell edge tensions – akin to a planar cell polarity that can drive elongation of cells in a direction parallel to the minimum edge tension – and identify regions of parameter space (edge-tension anisotropy versus stress anisotropy) that best match previous experiments for each germ band segment. All but three germ band segments are best fit when the applied stress anisotropy and the edge-tension anisotropy work against one another – i.e., when the isolated effects would elongate cells in perpendicular directions. Segments in the crook of the germ band (A4-A7) have cells that elongate in the direction of maximum external stress, i.e., external stress anisotropy is dominant. In most other segments, the dominant factor is internal edge-tension anisotropy. These results are consistent with models in which the amnioserosa pulls on the crook of the germ band to mechanically assist retraction. In addition, they suggest a mechanical cue for edge

  3. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice

    PubMed Central

    Fu, Chun; Begum, Khurshida; Jordan, Philip W.; He, Yan; Overbeek, Paul A.

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2–3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line. PMID:27486799

  4. Germ line versus soma in the transition from egg to embryo

    PubMed Central

    Swartz, S. Zachary; Wessel, Gary M.

    2016-01-01

    With few exceptions, all animals acquire the ability to produce eggs or sperm at some point in their lifecycle. Despite this near universal requirement for sexual reproduction, there exists an incredible diversity in germ-line development. For example, animals exhibit a vast range of differences in the timing at which the germ line, which retains reproductive potential, separates from the soma, or terminally differentiated, non-reproductive cells. This separation may occur during embryonic development, after gastrulation, or even in adults, depending on the organism. The molecular mechanisms of germ line segregation are also highly diverse, and intimately intertwined with the overall transition from a fertilized egg to an embryo. The earliest embryonic stages of many species are largely controlled by maternally supplied factors. Later in development, patterning control shifts to the embryonic genome and, concomitantly with this transition, the maternally supplied factors are broadly degraded. This chapter attempts to integrate these processes – germ line segregation, and how the divergence of germ line and soma may utilize the egg to embryo transitions differently. In some embryos, this difference is subtle or maybe lacking altogether, whereas in other embryos, this difference in utilization may be a key step in the divergence of the two lineages. Here we will focus our discussion on the echinoderms, and in particular the sea urchins, in which recent studies have provided mechanistic understanding in germ line determination. We propose that the germ line in sea urchins requires an acquisition of maternal factors from the egg and, when compared to other members of the taxon, this appears to be a derived mechanism. The acquisition is early – at the 32 cell stage – and involves active protection of maternal mRNAs, which are instead degraded in somatic cells with the maternal to embryonic transition. We collectively refer to this model as the Time Capsule method

  5. Automatic classification of fish germ cells through optimum-path forest.

    PubMed

    Papa, João P; Gutierrez, Mario E M; Nakamura, Rodrigo Y M; Papa, Luciene P; Vicentini, Irene B F; Vicentini, Carlos A

    2011-01-01

    The spermatogenesis is crucial to the species reproduction, and its monitoring may shed light over some important information of such process. Thus, the germ cells quantification can provide useful tools to improve the reproduction cycle. In this paper, we present the first work that address this problem in fishes with machine learning techniques. We show here how to obtain high recognition accuracies in order to identify fish germ cells with several state-of-the-art supervised pattern recognition techniques.

  6. Bmi1 expression in long-term germ stem cells

    PubMed Central

    Komai, Yoshihiro; Tanaka, Toshihiro; Tokuyama, Yoko; Yanai, Hirotsugu; Ohe, Shuichi; Omachi, Taichi; Atsumi, Naho; Yoshida, Naoko; Kumano, Keiki; Hisha, Hiroko; Matsuda, Tadashi; Ueno, Hiroo

    2014-01-01

    Asingle cells in undifferentiated spermatogonia are considered to be the most primitive forms of germ stem cells (GSCs). Although GFRα1 is thought to be a marker of Asingle cells, we found that Bmi1High is more specific than GFRα1 for Asingle cells. Bmi1High expression in Asingle cells is correlated with seminiferous stages, and its expression was followed by the proliferative stage of Asingle GSCs. In contrast, GFRα1 expression was seminiferous stage-independent. Fate analyses of EdU-positive Bmi1High-positive cell-derived Asingle cells revealed that these cells self-renewed or generated transient amplifying Apaired cells. Bmi1High-positive cells were resistant to irradiation-induced injury, after which they regenerated. Elimination of Bmi1High-positive cells from seminiferous tubules resulted in the appearance of tubules with seminiferous stage mismatches. Thus, in this study, we found that Bmi1High is a seminiferous stage-dependent marker for long-term GSCs and that Bmi1High-positive cells play important roles in maintaining GSCs and in regenerating spermatogenic progenitors after injury. PMID:25146451

  7. Generation of viable fish from cryopreserved primordial germ cells.

    PubMed

    Kobayashi, Terumasa; Takeuchi, Yutaka; Takeuchi, Toshio; Yoshizaki, Goro

    2007-02-01

    An increasing number of wild fish species are in danger of extinction, often as a result of human activities. The cryopreservation of gametes and embryos has great potential for maintaining and restoring threatened species. The conservation of both paternal and maternal genetic information is essential. However, although this technique has been successfully applied to the spermatozoa of many fish species, reliable methods are lacking for the long-term preservation of fish eggs and embryos. Here, we describe a protocol for use with rainbow trout (Oncorhynchus mykiss) primordial germ cells (PGCs) and document the restoration of live fish from gametes derived from these cryopreserved progenitors. Genital ridges (GRs), which are embryonic tissues containing PGCs, were successfully cryopreserved in a medium containing 1.8 M ethylene glycol (EG). The thawed PGCs that were transplanted into the peritoneal cavities of allogenic trout hatchlings differentiated into mature spermatozoa and eggs in the recipient gonads. Furthermore, the fertilization of eggs derived from cryopreserved PGCs by cryopreserved spermatozoa resulted in the development of fertile F1 fish. This PGC cryopreservation technique represents a promising tool in efforts to save threatened fish species. Moreover, this approach has significant potential for maintaining domesticated fish strains carrying commercially valuable traits for aquaculture purposes.

  8. Morphometric approach to pulp fibroblast development in tooth germ.

    PubMed

    Căruntu, Irina-Draga; Săvinescu, Sergiu Daniel; Amălinei, Cornelia

    2014-01-01

    This paper builds a morphometric framework for the analysis of dental pulp fibroblast evolution during tooth development. We investigated 15 tooth germs (cases) organized, by histological criteria, in three groups corresponding to cap, early bell, and late bell stages, respectively. Each group comprised five cases. The morphometric description used the following parameters: area (A), perimeter (P)--automatically extracted by a color segmentation technique, and form factor (FF)--calculated as 4πA/P (2). The designed framework operated at inter- and intragroup levels. The intergroup analysis quantified the differences between groups, in the sense of a relative distance (RD) adequately defined by mean-value scaling. We showed that the stage of early bell is approximately 5 times closer to late bell than to cap. The quantification procedure required concomitant information about A, P parameters (as P versus A dependences, or FF values), whereas the procedure failed for A or P separately used. The intragroup analysis quantified the similarity of the cases belonging to the same stage. We proved that, unlike the intergroup tests, the individual exploitation of all three descriptors A, P, and FF is effective, yielding highly compatible results. Within any group, most cases presented RDs less than 10% from the group mean value, regardless of the descriptor type.

  9. Morphometric Approach to Pulp Fibroblast Development in Tooth Germ

    PubMed Central

    Căruntu, Irina-Draga; Săvinescu, Sergiu Daniel; Amălinei, Cornelia

    2014-01-01

    This paper builds a morphometric framework for the analysis of dental pulp fibroblast evolution during tooth development. We investigated 15 tooth germs (cases) organized, by histological criteria, in three groups corresponding to cap, early bell, and late bell stages, respectively. Each group comprised five cases. The morphometric description used the following parameters: area (A), perimeter (P)—automatically extracted by a color segmentation technique, and form factor (FF)—calculated as 4πA/P2. The designed framework operated at inter- and intragroup levels. The intergroup analysis quantified the differences between groups, in the sense of a relative distance (RD) adequately defined by mean-value scaling. We showed that the stage of early bell is approximately 5 times closer to late bell than to cap. The quantification procedure required concomitant information about A, P parameters (as P versus A dependences, or FF values), whereas the procedure failed for A or P separately used. The intragroup analysis quantified the similarity of the cases belonging to the same stage. We proved that, unlike the intergroup tests, the individual exploitation of all three descriptors A, P, and FF is effective, yielding highly compatible results. Within any group, most cases presented RDs less than 10% from the group mean value, regardless of the descriptor type. PMID:25057501

  10. The Origin And Migration Of Primordial Germ Cells In Sturgeons

    PubMed Central

    Saito, Taiju; Pšenička, Martin; Goto, Rie; Adachi, Shinji; Inoue, Kunio; Arai, Katsutoshi; Yamaha, Etsuro

    2014-01-01

    Primordial germ cells (PGCs) arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser) have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT) assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts. PMID:24505272

  11. Poultry genetic resource conservation using primordial germ cells

    PubMed Central

    NAKAMURA, Yoshiaki

    2016-01-01

    The majority of poultry genetic resources are maintained in situ in living populations. However, in situ conservation of poultry genetic resources always carries the risk of loss owing to pathogen outbreaks, genetic problems, breeding cessation, or natural disasters. Cryobanking of germplasm in birds has been limited to the use of semen, preventing conservation of the W chromosome and mitochondrial DNA. A further challenge is posed by the structure of avian eggs, which restricts the cryopreservation of ova and fertilized embryos, a technique widely used for mammalian species. By using a unique biological property and accessibility of avian primordial germ cells (PGCs), precursor cells for gametes, which temporally circulate in the vasculature during early development, an avian PGC transplantation technique has been established. To date, several techniques for PGC manipulation including purification, cryopreservation, depletion, and long-term culture have been developed in chickens. PGC transplantation combined with recent advanced PGC manipulation techniques have enabled ex situ conservation of poultry genetic resources in their complete form. Here, the updated technologies for avian PGC manipulation are introduced, and then the concept of a poultry PGC-bank is proposed by considering the biological properties of avian PGCs. PMID:27210834

  12. Wheat-germ aspartate transcarbamoylase. Purification and cold-lability.

    PubMed Central

    Grayson, J E; Yon, R J; Butterworth, P J

    1979-01-01

    1. Aspartate transcarbamoylase was purified approx. 3000-fold from wheat (Triticum vulgare) germ in 15-20% yield. The product has a specific activity of 14 mumol/min per mg of protein and is approx. 90% pure. The purification scheme includes the use of biospecific "imphilyte" chromatography as described by Yon [Biochem.J.(1977) 161, 233-237]. The enzyme was passed successively through columns of CPAD [N-(3-carboxypropionyl)aminodecyl]-Sepharose in the absence and presence respectively of the ligands UMP and L-aspartate. In the second passage the enzyme was specifically displaced away from impurities with which it co-migrated in the first passage. These two steps contributed a factor of 80 to the overall purification. 2. The enzyme is slowly inactivated on dilution at 0 degrees C and pH 7.0, the inactivation being partially reversible. A detailed investigation of the temperature- and pH-dependence of the cold-inactivation suggested that it was initiated by the perturbation of the pKa values of groups with a moderately high and positive heat of ionization, which were tentatively identified as histidine residues. These findings support a new concept of cold-lability proposed by Bock, Gilbert & Frieden [Biochem. Biophys. Res. Commun. (1975) 66, 564-569]. PMID:43131

  13. [Clinical evaluation of nonseminomatous testicular germ cell tumors].

    PubMed

    Nukui, M; Nakao, M; Nakagawa, S; Takada, H; Ebisui, K; Sugimoto, K; Watanabe, H; Maekawa, M

    1991-10-01

    We treated 26 patients with nonseminomatous germ cell tumors (NSGCT) between January 1976 and March 1989. Histologically, 7 were embryonal carcinoma (27%), 4 were teratoma (15%), 2 were yolk sac tumor (8%), 10 were teratocarcinoma (38%) and 3 were other mixed tumors. As regards staging, 18 belonged to stage I (69%), 1 to stage II A (4%), 1 to stage IIB (4%), 1 to stage IIIA, 2 to stage III B1 (8%) and 3 to stage III B2 (12%). Patients in stage I were treated by orchidectomy with lymphadenectomy and occasionally chemotherapy before 1984, resulting in a 100% 5-year survival. However, after 1985, 5 cases in stage I were treated by orchidectomy alone according to a watch-and-see policy. Two cases among them relapsed within two years and both of them contained immature teratoma elements. Six patients with metastatic tumor were treated with PVB therapy of which response rate was 66.7%. The total 5-year survival rate of patients in stage I, II and III was 100%, 50%, 50%, respectively and that in overall cases was 84.6%.

  14. Familial testicular germ cell tumor: no associated syndromic pattern identified

    PubMed Central

    2014-01-01

    Background Testicular germ cell tumor (TGCT) is the most common malignancy in young men. Familial clustering, epidemiologic evidence of increased risk with family or personal history, and the association of TGCT with genitourinary (GU) tract anomalies have suggested an underlying genetic predisposition. Linkage data have not identified a rare, highly-penetrant, single gene in familial TGCT (FTGCT) cases. Based on its association with congenital GU tract anomalies and suggestions that there is an intrauterine origin to TGCT, we hypothesized the existence of unrecognized dysmorphic features in FTGCT. Methods We evaluated 38 FTGCT individuals and 41 first-degree relatives from 22 multiple-case families with detailed dysmorphology examinations, physician-based medical history and physical examination, laboratory testing, and genitourinary imaging studies. Results The prevalence of major abnormalities and minor variants did not significantly differ between either FTGCT individuals or their first-degree relatives when compared with normal population controls, except for tall stature, macrocephaly, flat midface, and retro-/micrognathia. However, these four traits were not manifest as a constellation of features in any one individual or family. We did detect an excess prevalence of the genitourinary anomalies cryptorchidism and congenital inguinal hernia in our population, as previously described in sporadic TGCT, but no congenital renal, retroperitoneal or mediastinal anomalies were detected. Conclusions Overall, our study did not identify a constellation of dysmorphic features in FTGCT individuals, which is consistent with results of genetic studies suggesting that multiple low-penetrance genes are likely responsible for FTGCT susceptibility. PMID:24559313

  15. Gonadogenesis and slow proliferation of germ cells in juveniles of cultured yellowfin tuna, Thunnus albacares.

    PubMed

    Kobayashi, Toru; Honryo, Tomoki; Agawa, Yasuo; Sawada, Yoshifumi; Tapia, Ileana; Macìas, Karla A; Cano, Amado; Scholey, Vernon P; Margulies, Daniel; Yagishita, Naoki

    2015-06-01

    To develop techniques for seedling production of yellowfin tuna, the behavior of primordial germ cells (PGCs) and gonadogenesis were examined at 1-30 days post hatching (dph) using morphometric analysis, histological examination, and in situ hybridization. Immediately after hatching, PGCs were located on the dorsal side of the posterior end of the rectum under the peritoneum of the larvae, and at 3 dph they came into contact with stromal cells. PGCs and stromal cells gradually moved forward from the anus prior to 5 dph. At 7-10 dph, germ cells were surrounded by stromal cells and the gonadal primordia were formed. In individuals collected at 12 dph, PGCs were detected by in situ hybridization using a vasa mRNA probe that is a germ-cell-specific detection marker. The proliferation of germ cells in the gonadal primordia began at 7-10 dph. We observed double the number of germ cells at 30 dph (22 ± 3.2 cells), compared to that at 1 dph (11 ± 2.1 cells). Therefore, based on our data and previous reports, the initial germ cell proliferation of yellowfin tuna is relatively slower than that of other fish species.

  16. Beyond the Mouse Monopoly: Studying the Male Germ Line in Domestic Animal Models

    PubMed Central

    González, Raquel; Dobrinski, Ina

    2015-01-01

    Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis and essential to maintain the continuous production of spermatozoa after the onset of puberty in the male. The study of the male germ line is important for understanding the process of spermatogenesis, unravelling mechanisms of stemness maintenance, cell differentiation, and cell-to-cell interactions. The transplantation of SSCs can contribute to the preservation of the genome of valuable individuals in assisted reproduction programs. In addition to the importance of SSCs for male fertility, their study has recently stimulated interest in the generation of genetically modified animals because manipulations of the male germ line at the SSC stage will be maintained in the long term and transmitted to the offspring. Studies performed mainly in the mouse model have laid the groundwork for facilitating advancements in the field of male germ line biology, but more progress is needed in nonrodent species in order to translate the technology to the agricultural and biomedical fields. The lack of reliable markers for isolating germ cells from testicular somatic cells and the lack of knowledge of the requirements for germ cell maintenance have precluded their long-term maintenance in domestic animals. Nevertheless, some progress has been made. In this review, we will focus on the state of the art in the isolation, characterization, culture, and manipulation of SSCs and the use of germ cell transplantation in domestic animals. PMID:25991701

  17. Human germ cell differentiation from fetal- and adult-derived induced pluripotent stem cells

    PubMed Central

    Panula, Sarita; Medrano, Jose V.; Kee, Kehkooi; Bergström, Rosita; Nguyen, Ha Nam; Byers, Blake; Wilson, Kitchener D.; Wu, Joseph C.; Simon, Carlos; Hovatta, Outi; Reijo Pera, Renee A.

    2011-01-01

    Historically, our understanding of molecular genetic aspects of human germ cell development has been limited, at least in part due to inaccessibility of early stages of human development to experimentation. However, the derivation of pluripotent stem cells may provide the necessary human genetic system to study germ cell development. In this study, we compared the potential of human induced pluripotent stem cells (iPSCs), derived from adult and fetal somatic cells to form primordial and meiotic germ cells, relative to human embryonic stem cells. We found that ∼5% of human iPSCs differentiated to primordial germ cells (PGCs) following induction with bone morphogenetic proteins. Furthermore, we observed that PGCs expressed green fluorescent protein from a germ cell-specific reporter and were enriched for the expression of endogenous germ cell-specific proteins and mRNAs. In response to the overexpression of intrinsic regulators, we also observed that iPSCs formed meiotic cells with extensive synaptonemal complexes and post-meiotic haploid cells with a similar pattern of ACROSIN staining as observed in human spermatids. These results indicate that human iPSCs derived from reprogramming of adult somatic cells can form germline cells. This system may provide a useful model for molecular genetic studies of human germline formation and pathology and a novel platform for clinical studies and potential therapeutical applications. PMID:21131292

  18. Early segregation of germ and somatic lineages during gonadal regeneration in the annelid Enchytraeus japonensis.

    PubMed

    Tadokoro, Ryosuke; Sugio, Mutsumi; Kutsuna, Junko; Tochinai, Shin; Takahashi, Yoshiko

    2006-05-23

    Although regeneration studies are useful for understanding how organs renew, little information is available about regeneration of reproductive organs and germ cells. We here describe the behavior of germ-cell precursors during regeneration of the oligochaete annelid worm Enchytraeus japonensis, which has the remarkable feature of undergoing asexual (by fission) and sexual reproduction . We first found that the gonad can regenerate from any body fragment yielded by fission during asexual reproduction. We then examined behavior of germ-cell lineage during this regenerative process, by using a homolog of the Piwi gene (Ej-piwi) as a marker. We found that in asexually growing animals, specialized cells expressing Ej-piwi are distributed widely in the body as single cells. These cells seem to serve as a reservoir of germ-cell precursors because during asexual propagation these cells migrate into the regenerating tissue, where they ultimately settle in the prospective gonads, and give rise to germ cells upon sexualization. These cells are distinct from the neoblasts, thought to be stem cells in other animals. This is the first report to directly show that the germ and somatic lineages are segregated in asexually growing animals and behave differently during regeneration.

  19. Germ cells of the centipede Strigamia maritima are specified early in embryonic development.

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    We provide the first systematic description of germ cell development with molecular markers in a myriapod, the centipede Strigamia maritima. By examining the expression of Strigamia vasa and nanos orthologues, we find that the primordial germ cells are specified from at least the blastoderm stage. This is a much earlier embryonic stage than previously described for centipedes, or any other member of the Myriapoda. Using these genes as markers, and taking advantage of the developmental synchrony of Strigamia embryos within single clutches, we are able to track the development of the germ cells throughout embryogenesis. We find that the germ cells accumulate at the blastopore; that the cells do not internalize through the hindgut, but rather through the closing blastopore; and that the cells undergo a long-range migration to the embryonic gonad. This is the first evidence for primordial germ cells displaying these behaviours in any myriapod. The myriapods are a phylogenetically important group in the arthropod radiation for which relatively little developmental data is currently available. Our study provides valuable comparative data that complements the growing number of studies in insects, crustaceans and chelicerates, and is important for the correct reconstruction of ancestral states and a fuller understanding of how germ cell development has evolved in different arthropod lineages.

  20. Zebrafish vasa is required for germ-cell differentiation and maintenance.

    PubMed

    Hartung, Odelya; Forbes, Meredyth M; Marlow, Florence L

    2014-10-01

    Vasa is a universal marker of the germ line in animals, yet mutations disrupting vasa cause sexually dimorphic infertility, with impaired development of the ovary in some animals and the testis in others. The basis for this sexually dimorphic requirement for Vasa is not clear; in most animals examined, both the male and female gonad express vasa throughout the life of the germ line. Here we characterized a loss-of-function mutation disrupting zebrafish vasa. We show that maternally provided Vasa is stable through the first ten days of development in zebrafish, and thus likely fulfills any early roles for Vasa during germ-line specification, migration, survival, and maintenance. Although zygotic Vasa is not essential for the development of juvenile gonads, vasa mutants develop exclusively as sterile males. Furthermore, phenotypes of vasa;p53 compound mutants are indistinguishable from those of vasa mutants, therefore the failure of vasa mutants to differentiate as females and to support germ-cell development in the testis is not due to p53-mediated apoptosis. Instead, we found that failure to progress beyond the pachytene stage of meiosis causes the loss of germ-line stem cells, leaving empty somatic tubules. Our studies provide insight into the function of zebrafish vasa during female meiosis, differentiation, and maintenance of germ-line stem cells.

  1. Recovery from Choriocarcinoma Syndrome Associated with a Metastatic Extragonadal Germ Cell Tumor Hemorrhage

    PubMed Central

    Komori, Koji; Takahari, Daisuke; Kimura, Kenya; Kinoshita, Takashi; Ito, Seiji; Abe, Tetsuya; Senda, Yoshiki; Misawa, Kazunari; Ito, Yuichi; Uemura, Norihisa; Natsume, Seiji; Kawakami, Jiro; Iwata, Yoshinori; Tsutsuyama, Masayuki; Shigeyoshi, Itaru; Akazawa, Tomoyuki; Hayashi, Daisuke; Ouchi, Akira; Shimizu, Yasuhiro

    2016-01-01

    A germ cell tumor is the most common form of malignancy in early male life, and can be classified as either seminomatous or nonseminomatous. Choriocarcinoma, comprised of nonseminomatous germ cells, is the most aggressive type of germ cell tumor and characteristically metastasizes to the retroperitoneal lymph nodes and less frequently to the lungs, liver, bone or brain [Shibuya et al., 2009;48: 551–554]. A 56-year-old man was admitted to another hospital complaining of abdominal distension. Symptoms included anorexia, vomiting, and diarrhea. The patient was diagnosed with an extragonadal germ cell tumor and referred to our hospital to receive chemotherapy. The day after admission, the patient's abdominal distension gradually worsened. An emergency operation revealed venous hemorrhage from the surface of a metastatic extragonadal germ cell tumor between the ligament of Treitz and the inferior mesenteric vein in a horizontal position. Hemostatic treatment was performed with 4-0 proline thread attached to a medicated cotton sponge, rather than using a simple proline thread, and the closure area was manually compressed. Chemotherapy was initiated on postoperative day 10. A metastatic extragonadal germ cell tumor that causes massive hemorrhage and gastrointestinal hemorrhage is very rare, and represents a life-threatening emergency. If the patient's condition carries a substantial risk of bleeding to death, it may be worthwhile to attempt abdominal operations. PMID:27403124

  2. Gonadogenesis and slow proliferation of germ cells in juveniles of cultured yellowfin tuna, Thunnus albacares.

    PubMed

    Kobayashi, Toru; Honryo, Tomoki; Agawa, Yasuo; Sawada, Yoshifumi; Tapia, Ileana; Macìas, Karla A; Cano, Amado; Scholey, Vernon P; Margulies, Daniel; Yagishita, Naoki

    2015-06-01

    To develop techniques for seedling production of yellowfin tuna, the behavior of primordial germ cells (PGCs) and gonadogenesis were examined at 1-30 days post hatching (dph) using morphometric analysis, histological examination, and in situ hybridization. Immediately after hatching, PGCs were located on the dorsal side of the posterior end of the rectum under the peritoneum of the larvae, and at 3 dph they came into contact with stromal cells. PGCs and stromal cells gradually moved forward from the anus prior to 5 dph. At 7-10 dph, germ cells were surrounded by stromal cells and the gonadal primordia were formed. In individuals collected at 12 dph, PGCs were detected by in situ hybridization using a vasa mRNA probe that is a germ-cell-specific detection marker. The proliferation of germ cells in the gonadal primordia began at 7-10 dph. We observed double the number of germ cells at 30 dph (22 ± 3.2 cells), compared to that at 1 dph (11 ± 2.1 cells). Therefore, based on our data and previous reports, the initial germ cell proliferation of yellowfin tuna is relatively slower than that of other fish species. PMID:26051459

  3. Germ cells of the centipede Strigamia maritima are specified early in embryonic development.

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    We provide the first systematic description of germ cell development with molecular markers in a myriapod, the centipede Strigamia maritima. By examining the expression of Strigamia vasa and nanos orthologues, we find that the primordial germ cells are specified from at least the blastoderm stage. This is a much earlier embryonic stage than previously described for centipedes, or any other member of the Myriapoda. Using these genes as markers, and taking advantage of the developmental synchrony of Strigamia embryos within single clutches, we are able to track the development of the germ cells throughout embryogenesis. We find that the germ cells accumulate at the blastopore; that the cells do not internalize through the hindgut, but rather through the closing blastopore; and that the cells undergo a long-range migration to the embryonic gonad. This is the first evidence for primordial germ cells displaying these behaviours in any myriapod. The myriapods are a phylogenetically important group in the arthropod radiation for which relatively little developmental data is currently available. Our study provides valuable comparative data that complements the growing number of studies in insects, crustaceans and chelicerates, and is important for the correct reconstruction of ancestral states and a fuller understanding of how germ cell development has evolved in different arthropod lineages. PMID:24930702

  4. Recovery from Choriocarcinoma Syndrome Associated with a Metastatic Extragonadal Germ Cell Tumor Hemorrhage.

    PubMed

    Komori, Koji; Takahari, Daisuke; Kimura, Kenya; Kinoshita, Takashi; Ito, Seiji; Abe, Tetsuya; Senda, Yoshiki; Misawa, Kazunari; Ito, Yuichi; Uemura, Norihisa; Natsume, Seiji; Kawakami, Jiro; Iwata, Yoshinori; Tsutsuyama, Masayuki; Shigeyoshi, Itaru; Akazawa, Tomoyuki; Hayashi, Daisuke; Ouchi, Akira; Shimizu, Yasuhiro

    2016-01-01

    A germ cell tumor is the most common form of malignancy in early male life, and can be classified as either seminomatous or nonseminomatous. Choriocarcinoma, comprised of nonseminomatous germ cells, is the most aggressive type of germ cell tumor and characteristically metastasizes to the retroperitoneal lymph nodes and less frequently to the lungs, liver, bone or brain [Shibuya et al., 2009;48: 551-554]. A 56-year-old man was admitted to another hospital complaining of abdominal distension. Symptoms included anorexia, vomiting, and diarrhea. The patient was diagnosed with an extragonadal germ cell tumor and referred to our hospital to receive chemotherapy. The day after admission, the patient's abdominal distension gradually worsened. An emergency operation revealed venous hemorrhage from the surface of a metastatic extragonadal germ cell tumor between the ligament of Treitz and the inferior mesenteric vein in a horizontal position. Hemostatic treatment was performed with 4-0 proline thread attached to a medicated cotton sponge, rather than using a simple proline thread, and the closure area was manually compressed. Chemotherapy was initiated on postoperative day 10. A metastatic extragonadal germ cell tumor that causes massive hemorrhage and gastrointestinal hemorrhage is very rare, and represents a life-threatening emergency. If the patient's condition carries a substantial risk of bleeding to death, it may be worthwhile to attempt abdominal operations. PMID:27403124

  5. Primary Mediastinal Classical Hodgkin Lymphoma.

    PubMed

    Piña-Oviedo, Sergio; Moran, Cesar A

    2016-09-01

    Primary mediastinal Classical Hodgkin lymphoma (CHL) is rare. Nodular sclerosis CHL (NS-CHL) is the most common subtype involving the anterior mediastinum and/or mediastinal lymph nodes. Primary thymic CHL is exceedingly rare. The disease typically affects young women and is asymptomatic in 30% to 50% of patients. Common symptoms include fatigue, chest pain, dyspnea and cough, but vary depending on the location and size of the tumor. B-symptoms develop in 30% of cases. By imaging, primary mediastinal CHL presents as mediastinal widening/mediastinal mass that does not invade adjacent organs but may compress vital structures as bulky disease. Histopathology is the gold standard for diagnosis. Primary mediastinal NS-CHL consists of nodules of polymorphous inflammatory cells surrounded by broad fibrous bands extending from a thickened lymph node capsule. The cellular nodules contain variable numbers of large Hodgkin/Reed-Sternberg cells, required for diagnosis. Primary thymic CHL may exhibit prominent cystic changes. The histopathologic recognition of NS-CHL can be challenging in cases with prominent fibrosis, scant cellularity, artifactual cell distortion, or an exuberant granulomatous reaction. The differential diagnosis includes primary mediastinal non-HLs, mediastinal germ cell tumors, thymoma, and metastatic carcinoma or melanoma to the mediastinum. Distinction from primary mediastinal non-HLs is crucial for adequate therapeutic decisions. Approximately 95% of patients with primary mediastinal CHL will be alive and free of disease at 10 years after treatment with short courses of combined chemoradiotherapy. In this review, we discuss the history, classification, epidemiology, clinicoradiologic features, histopathology, immunohistochemistry, differential diagnosis, and treatment of primary mediastinal CHL. PMID:27441757

  6. The transcriptional repressor Blimp-1 acts downstream of BMP signaling to generate primordial germ cells in the cricket Gryllus bimaculatus.

    PubMed

    Nakamura, Taro; Extavour, Cassandra G

    2016-01-15

    Segregation of the germ line from the soma is an essential event for transmission of genetic information across generations in all sexually reproducing animals. Although some well-studied systems such as Drosophila and Xenopus use maternally inherited germ determinants to specify germ cells, most animals, including mice, appear to utilize zygotic inductive cell signals to specify germ cells during later embryogenesis. Such inductive germ cell specification is thought to be an ancestral trait of Bilateria, but major questions remain as to the nature of an ancestral mechanism to induce germ cells, and how that mechanism evolved. We previously reported that BMP signaling-based germ cell induction is conserved in both the mouse Mus musculus and the cricket Gryllus bimaculatus, which is an emerging model organism for functional studies of induction-based germ cell formation. In order to gain further insight into the functional evolution of germ cell specification, here we examined the Gryllus ortholog of the transcription factor Blimp-1 (also known as Prdm1), which is a widely conserved bilaterian gene known to play a crucial role in the specification of germ cells in mice. Our functional analyses of the Gryllus Blimp-1 ortholog revealed that it is essential for Gryllus primordial germ cell development, and is regulated by upstream input from the BMP signaling pathway. This functional conservation of the epistatic relationship between BMP signaling and Blimp-1 in inductive germ cell specification between mouse and cricket supports the hypothesis that this molecular mechanism regulated primordial germ cell specification in a last common bilaterian ancestor.

  7. Fat absorption in germ-free and conventional rats artificially deprived of bile secretion.

    PubMed Central

    Demarne, Y; Corring, T; Pihet, A; Sacquet, E

    1982-01-01

    Bile duct ligation was performed in germ-free and conventional rats in order to study the effects of bile deprivation on the absorption of dietary lipids and the excretion of faecal lipids in the presence or the absence of gastrointestinal flora. The main consequence of bile duct ligation in conventional rats was decrease of about 50% in the apparent absorption of dietary lipids (peanut oil). In germ-free rats, absorption decreased by only about 25%.In conventional as well as in germ-free controls, faecal lipids were mainly excreted as compounds directly soluble in organic solvents that is, free fatty acids, triglycerides, partial glycerides, cholesterol, cholesterol esters. Deprivation of bile secretion significantly increased the faecal excretion of 'insoluble' compounds-that is, calcium soaps-both in germ-free and conventional rats. Free fatty acids and sterol esters were the two main class of soluble faecal lipids both in germ-free and conventional rats deprived of bile secretion. Faecal excretion of triglycerides remained low in germ-free as well as in conventional animals. No significant difference of fatty acid absorption was observed between germ-free and conventional controls. Deprivation of bile secretion resulted in a significant decrease in the absorption of all fatty acids in germ-free as well as in conventional animals. However, the decrease was larger for saturated fatty acids-that is, 16:0 or 18:0- than for unsaturated fatty acids-that is, 18:1 or 18:2. The absorption of all fatty acids, except linoleic acid (18:2), was significantly lower in conventional rats artificially deprived of bile secretion than in their germ-free counterparts. Evidence was given for a negative digestive balance of stearic acid (18:0) in bile deprived conventional animals. This observation was correlated with a very efficient biohydrogenation of dietary unsaturated fatty acids as revealed by radio gas chromatography of faecal acids in bile deprived conventional rats fed a

  8. Chicken stem cell factor enhances primordial germ cell proliferation cooperatively with fibroblast growth factor 2.

    PubMed

    Miyahara, Daichi; Oishi, Isao; Makino, Ryuichi; Kurumisawa, Nozomi; Nakaya, Ryuma; Ono, Tamao; Kagami, Hiroshi; Tagami, Takahiro

    2016-04-22

    An in vitro culture system of chicken primordial germ cells (PGCs) has been recently developed, but the growth factor involved in the proliferation of PGCs is largely unknown. In the present study, we investigated the growth effects of chicken stem cell factor (chSCF) on the in vitro proliferation of chicken PGCs. We established two feeder cell lines (buffalo rat liver cells; BRL cells) that stably express the putative secreted form of chSCF (chSCF1-BRL) and membrane bound form of chSCF (chSCF2-BRL). Cultured PGC lines were incubated on chSCF1 or chSCF2-BRL feeder cells with fibroblast growth factor 2 (FGF2), and growth effects of each chSCF isoform were investigated. The in vitro proliferation rate of the PGCs cultured on chSCF2-BRL at 20 days of culture was more than threefold higher than those cultured on chSCF1-BRL cells and more than fivefold higher than those cultured on normal BRL cells. Thus, use of chSCF2-BRL feeder layer was effective for in vitro proliferation of chicken PGCs. However, the acceleration of PGC proliferation on chSCF2-BRL was not observed without FGF2, suggesting that chSCF2 would act as a proliferation co-factor of FGF2. We transferred the PGCs cultured on chSCF2-BRL cells to recipient embryos, generated germline chimeric chickens and assessed the germline competency of cultured PGCs by progeny test. Donor-derived progenies were obtained, and the frequency of germline transmission was 3.39%. The results of this study demonstrate that chSCF2 induces hyperproliferation of chicken PGCs retaining germline competency in vitro in cooperation with FGF2. PMID:26727404

  9. In vitro production of haploid sperm cells from male germ cells of foetal cattle.

    PubMed

    Dong, Wu-Zi; Hua, Jin-Lian; Shen, Wen-Zheng; Dou, Zhong-Ying

    2010-04-01

    The purpose of this study was to isolate the foetal cattle male germ cells (mGCs) and then induce them into sperm cells. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the vasa and the c-kit positive cells were 95.34+/-2.25% and 53.3+/-1.03% by using flow cytometry analysis (FCA), respectively. In feeder-free culture system, the half-suspending cells appeared and formed a 16-cell rosary in medium after the mGCs were cultured for 6-8 days. On immunocytochemical staining during the second passage, some single cells adhering to the plate appeared to be both Oct-4 and alpha6-integrin positive. During the third passage, the mGCs were induced for 48 h by retinol acid (RA) on Sertoli cell-feeder layer, followed by 5-7 days culture in an RA-free medium. Some elongated sperm-like cells appeared in the medium at this stage. We found that the most effective concentration of RA for the inducement was 10(-7)moll(-1) (P<0.01). The haploid cells in suspension were identified by FCA. The elongated sperm-like cells showed proacrosome-like structure and the flagellum with fibre construct under electron microscopy. The mRNA of outer dense fibre-3 (ODF-3) and transcription protein-1 (TP-1) could be detected in the suspended cells by using reverse transcription polymerase chain reaction (RT-PCR). About 23.1% bovine oocytes could be activated to perform cleavage by intracytoplasmic injection with the sperm-like cells, but embryos did not further develop. Our investigation further demonstrated that foetal cattle mGCs could be induced in vitro into haploid sperm in the short term. PMID:19632794

  10. In vitro production of haploid sperm cells from male germ cells of foetal cattle.

    PubMed

    Dong, Wu-Zi; Hua, Jin-Lian; Shen, Wen-Zheng; Dou, Zhong-Ying

    2010-04-01

    The purpose of this study was to isolate the foetal cattle male germ cells (mGCs) and then induce them into sperm cells. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the vasa and the c-kit positive cells were 95.34+/-2.25% and 53.3+/-1.03% by using flow cytometry analysis (FCA), respectively. In feeder-free culture system, the half-suspending cells appeared and formed a 16-cell rosary in medium after the mGCs were cultured for 6-8 days. On immunocytochemical staining during the second passage, some single cells adhering to the plate appeared to be both Oct-4 and alpha6-integrin positive. During the third passage, the mGCs were induced for 48 h by retinol acid (RA) on Sertoli cell-feeder layer, followed by 5-7 days culture in an RA-free medium. Some elongated sperm-like cells appeared in the medium at this stage. We found that the most effective concentration of RA for the inducement was 10(-7)moll(-1) (P<0.01). The haploid cells in suspension were identified by FCA. The elongated sperm-like cells showed proacrosome-like structure and the flagellum with fibre construct under electron microscopy. The mRNA of outer dense fibre-3 (ODF-3) and transcription protein-1 (TP-1) could be detected in the suspended cells by using reverse transcription polymerase chain reaction (RT-PCR). About 23.1% bovine oocytes could be activated to perform cleavage by intracytoplasmic injection with the sperm-like cells, but embryos did not further develop. Our investigation further demonstrated that foetal cattle mGCs could be induced in vitro into haploid sperm in the short term.

  11. Global deletion of Trp53 reverts ovarian tumor phenotype of the germ cell-deficient white spotting variant (Wv) mice.

    PubMed

    Cai, Kathy Qi; Wang, Ying; Smith, Elizabeth R; Smedberg, Jennifer L; Yang, Dong-Hua; Yang, Wan-Lin; Xu, Xiang-Xi

    2015-01-01

    White spotting variant (Wv) mice are spontaneous mutants attributed to a point mutation in the c-Kit gene, which reduces the tyrosine kinase activity to around 1% and affects the development of melanocytes, mast cells, and germ cells. Homozygous mutant mice are sterile but can live nearly a normal life span. The female Wv mice have a greatly reduced ovarian germ cell and follicle reserve at birth, and the remaining follicles are largely depleted soon after the females reach reproductive stage at around 7 weeks of age. Consequently, ovarian epithelial tumors develop in 100% of Wv females by 3 to 4 months of age. These tumors, called tubular adenomas, are benign but can become invasive in older Wv mice. We tested if additional genetic mutation(s) could convert the benign ovarian epithelial tumors to malignant tumors by crossing the Wv mutant into the Trp53 knockout background. Surprisingly, we found that global deletion of Trp53 suppressed the development of ovarian tubular adenomas in Wv mice. The ovaries of Wv/Wv; Trp53 (-/-) mice were covered by a single layer of surface epithelium and lacked excessive epithelial proliferation. Rather, the ovaries contained a small number of follicles. The presence of ovarian follicles and granulosa cells, as indicated by Pgc7 and inhibin-alpha expression, correlated with the absence of epithelial lesions. A reduction of Pten gene dosage, as in Wv/Wv; Pten (+/-) mice, produced a similar, though less dramatic, phenotype. We conclude that deletion of Trp53 prolongs the survival of ovarian follicles in Wv mice and consequently prevents the proliferation of ovarian epithelial cells and development of ovarian tubular adenomas. The results suggest that various cell types within the ovary communicate and mutually modulate, and an intact tissue environment is required to ensure homeostasis of ovarian surface epithelial cells. Especially, the current finding emphasizes the importance of ovarian follicles in suppressing the hyperplastic

  12. Time series analysis supporting the hypothesis that enhanced cosmic radiation during germ cell formation can increase breast cancer mortality in germ cell cohorts

    NASA Astrophysics Data System (ADS)

    Juckett, D. A.; Rosenberg, Barnett

    Techniques from cancer epidemiology and time series analysis were used to explore the hypothesis that cosmic radiation can induce germ cell changes leading to increases in future breast cancer mortality. A birth cohort time series for female breast cancer mortality was obtained using a model-independent, age-period-cohort analysis on age-specific mortality data for 1940-1990. The birth cohort series contained several oscillatory components, which were isolated and compared to the corresponding frequency components of a cosmic ray surrogate time series - Greenland ice-core 10Be concentrations. A technique, referred to as component wave-train alignment, was used to show that the breast cancer and cosmic ray oscillations were phase-locked approx. 25 years before the time of birth. This is consistent with the time of germ cell formation, which occurs during the fetal development stage of the preceding generation. Evidence is presented that the observable oscillations in the birth cohort series were residues of oscillations of much larger amplitude in the germ cell cohort, which were attenuated by the effect of the broad maternal age distribution. It is predicted that a minimum of 50% of breast cancer risk is associated with germ cell damage by cosmic radiation (priming event), which leads to the development of individuals with a higher risk of breast cancer. It is proposed that the priming event, by preceding other steps of carcinogenesis, works in concert with risk factor exposure during life. The priming event is consistent with epigenetic changes such as imprinting.

  13. The PUF binding landscape in metazoan germ cells

    PubMed Central

    Prasad, Aman; Porter, Douglas F.; Kroll-Conner, Peggy L.; Mohanty, Ipsita; Ryan, Anne R.; Crittenden, Sarah L.; Wickens, Marvin; Kimble, Judith

    2016-01-01

    PUF (Pumilio/FBF) proteins are RNA-binding proteins and conserved stem cell regulators. The Caenorhabditis elegans PUF proteins FBF-1 and FBF-2 (collectively FBF) regulate mRNAs in germ cells. Without FBF, adult germlines lose all stem cells. A major gap in our understanding of PUF proteins, including FBF, is a global view of their binding sites in their native context (i.e., their “binding landscape”). To understand the interactions underlying FBF function, we used iCLIP (individual-nucleotide resolution UV crosslinking and immunoprecipitation) to determine binding landscapes of C. elegans FBF-1 and FBF-2 in the germline tissue of intact animals. Multiple iCLIP peak-calling methods were compared to maximize identification of both established FBF binding sites and positive control target mRNAs in our iCLIP data. We discovered that FBF-1 and FBF-2 bind to RNAs through canonical as well as alternate motifs. We also analyzed crosslinking-induced mutations to map binding sites precisely and to identify key nucleotides that may be critical for FBF–RNA interactions. FBF-1 and FBF-2 can bind sites in the 5′UTR, coding region, or 3′UTR, but have a strong bias for the 3′ end of transcripts. FBF-1 and FBF-2 have strongly overlapping target profiles, including mRNAs and noncoding RNAs. From a statistically robust list of 1404 common FBF targets, 847 were previously unknown, 154 were related to cell cycle regulation, three were lincRNAs, and 335 were shared with the human PUF protein PUM2. PMID:27165521

  14. Properties of the subunits of wheat germ initiation factor 3.

    PubMed

    Heufler, C; Browning, K S; Ravel, J M

    1988-11-10

    Wheat germ initiation factor 3 (eukaryotic initiation factor 3, eIF-3) contains ten non-identical subunits (p116, p107, p87, p83, p56, p45, p41, p36, p34 and p28). Monoclonal antibodies to all except two of the subunits (p41 and p28) were obtained. None of the monoclonal antibodies react with more than one subunit, and only monoclonal antibodies to p36 inhibit the ability of eIF-3 to support initiation of polypeptide synthesis. Two of the subunits (p116 and p107) are highly basic polypeptides (pI greater than or equal to 8); five (p87, p56, p45, p34 and p28) are acidic polypeptides (pI = 5.4-6.1); and three (p83, p41 and p36) appear to exist in more than one isoelectric form. Eight of the subunits of eIF-3 are iodinated rapidly in vitro; the highest incorporation is into p56 and the lowest incorporation is into p28. No incorporation into p41 or p28 is observed. When eIF-3 is treated with N-[3H]ethylmaleimide, approx. 30 alkyl groups per eIF-3 are incorporated, and the eIF-3 is inactivated. No incorporation into p83 or p28 is observed; incorporation of the alkyl groups into the other eight subunits occurs at different rates. The rate of inactivation of eIF-3 by N-ethylmaleimide is slower than the overall rate of incorporation of alkyl groups. eIF-3 is stable between pH 5.5 and 10. Below pH 5.5, eIF-3 is inactivated and precipitation of protein occurs. Partial dissociation of the subunits and inactivation of eIF-3 is obtained by treatment with 2 M urea. Attempts to reassociate the subunits into an active particle were unsuccessful.

  15. Endogenous DNA Damage and Risk of Testicular Germ Cell Tumors

    SciTech Connect

    Cook, M B; Sigurdson, A J; Jones, I M; Thomas, C B; Graubard, B I; Korde, L; Greene, M H; McGlynn, K A

    2008-01-18

    Testicular germ cell tumors (TGCT) are comprised of two histologic groups, seminomas and nonseminomas. We postulated that the possible divergent pathogeneses of these histologies may be partially explained by variable endogenous DNA damage. To assess our hypothesis, we conducted a case-case analysis of seminomas and nonseminomas using the alkaline comet assay to quantify single-strand DNA breaks and alkali-labile sites. The Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort provided 112 TGCT cases (51 seminomas & 61 nonseminomas). A lymphoblastoid cell line was cultured for each patient and the alkaline comet assay was used to determine four parameters: tail DNA, tail length, comet distributed moment (CDM) and Olive tail moment (OTM). Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. Values for tail length, tail DNA, CDM and OTM were modeled as categorical variables using the 50th and 75th percentiles of the seminoma group. Tail DNA was significantly associated with nonseminoma compared to seminoma (OR{sub 50th percentile} = 3.31, 95%CI: 1.00, 10.98; OR{sub 75th percentile} = 3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR{sub 50th percentile} = 2.27, 95%CI: 0.75, 6.87; OR{sub 75th percentile} = 2.40, 95%CI: 0.75, 7.71; p for trend=0.12) whereas tail length and CDM showed no association. In conclusion, the results for tail DNA and OTM indicate that endogenous DNA damage levels are higher in patients who develop nonseminoma compared with seminoma. This may partly explain the more aggressive biology and younger age-of-onset of this histologic subgroup compared with the relatively less aggressive, later-onset seminoma.

  16. Germ Cell-Specific Excision of loxP-Flanked Transgenes in Rainbow Trout Oncorhynchus mykiss.

    PubMed

    Katayama, Naoto; Kume, Sachi; Hattori-Ihara, Shoko; Sadaie, Sakiko; Hayashi, Makoto; Yoshizaki, Goro

    2016-04-01

    Cre/loxP-mediated DNA excision in germ cell lineages could contribute substantially to the study of germ cell biology in salmonids, which are emerging as a model species in this field. However, a cell type-specific Cre/loxPsystem has not been successfully developed for any salmonid species. Therefore, we examined the feasibility of Cre/loxP-mediated, germ cell-specific gene excision and transgene activation in rainbow trout. Double-transgenic (wTg) progeny were obtained by mating a transgenic male carryingcrewith a transgenic female carrying thehsc-LRLGgene;crewas driven by rainbow troutvasaregulatory regions and thehsc-LRLGgene was made up of the rainbow troutheat-shock-cognate71promoter, theDsRedgene flanked by twoloxPsites, and theEgfpgene. PCR analysis, fluorescence imaging, and histological analysis revealed that excision of theloxP-flanked sequence and activation ofEgfpoccurred only in germ cells of wTg fish. However, progeny tests revealed that the excision efficiency ofloxP-flanked sequence in germ cells was low (≤3.27%). In contrast, the other wTg fish derived from two differentcre-transgenic males frequently excised theloxP-flanked sequence in germ cells (≤89.25%). Thus, we showed for the first time successful germ cell-specific transgene manipulation via the Cre/loxPsystem in rainbow trout. We anticipate that this technology will be suitable for studies of cell function through cell targeting, cell-linage tracing, and generating cell type-specific conditional gene knockouts and separately for developing sterile rainbow trout in aquaculture. PMID:26911430

  17. Germ Cell-Specific Excision of loxP-Flanked Transgenes in Rainbow Trout Oncorhynchus mykiss.

    PubMed

    Katayama, Naoto; Kume, Sachi; Hattori-Ihara, Shoko; Sadaie, Sakiko; Hayashi, Makoto; Yoshizaki, Goro

    2016-04-01

    Cre/loxP-mediated DNA excision in germ cell lineages could contribute substantially to the study of germ cell biology in salmonids, which are emerging as a model species in this field. However, a cell type-specific Cre/loxPsystem has not been successfully developed for any salmonid species. Therefore, we examined the feasibility of Cre/loxP-mediated, germ cell-specific gene excision and transgene activation in rainbow trout. Double-transgenic (wTg) progeny were obtained by mating a transgenic male carryingcrewith a transgenic female carrying thehsc-LRLGgene;crewas driven by rainbow troutvasaregulatory regions and thehsc-LRLGgene was made up of the rainbow troutheat-shock-cognate71promoter, theDsRedgene flanked by twoloxPsites, and theEgfpgene. PCR analysis, fluorescence imaging, and histological analysis revealed that excision of theloxP-flanked sequence and activation ofEgfpoccurred only in germ cells of wTg fish. However, progeny tests revealed that the excision efficiency ofloxP-flanked sequence in germ cells was low (≤3.27%). In contrast, the other wTg fish derived from two differentcre-transgenic males frequently excised theloxP-flanked sequence in germ cells (≤89.25%). Thus, we showed for the first time successful germ cell-specific transgene manipulation via the Cre/loxPsystem in rainbow trout. We anticipate that this technology will be suitable for studies of cell function through cell targeting, cell-linage tracing, and generating cell type-specific conditional gene knockouts and separately for developing sterile rainbow trout in aquaculture.

  18. HMGA2 expression distinguishes between different types of postpubertal testicular germ cell tumour.

    PubMed

    Kloth, Lars; Gottlieb, Andrea; Helmke, Burkhard; Wosniok, Werner; Löning, Thomas; Burchardt, Käte; Belge, Gazanfer; Günther, Kathrin; Bullerdiek, Jörn

    2015-10-01

    The group of postpubertal testicular germ cell tumours encompasses lesions with highly diverse differentiation - seminomas, embryonal carcinomas, yolk sac tumours, teratomas and choriocarcinomas. Heterogeneous differentiation is often present within individual tumours and the correct identification of the components is of clinical relevance. HMGA2 re-expression has been reported in many tumours, including testicular germ cell tumours. This is the first study investigating HMGA2 expression in a representative group of testicular germ cell tumours with the highly sensitive method of quantitative real-time PCR as well as with immunohistochemistry. The expression of HMGA2 and HPRT was measured using quantitative real-time PCR in 59 postpubertal testicular germ cell tumours. Thirty specimens contained only one type of tumour and 29 were mixed neoplasms. With the exception of choriocarcinomas, at least two pure specimens from each subgroup of testicular germ cell tumour were included. In order to validate the quantitative real-time PCR data and gather information about the localisation of the protein, additional immunohistochemical analysis with an antibody specific for HMGA2 was performed in 23 cases. Expression of HMGA2 in testicular germ cell tumours depended on the histological differentiation. Seminomas and embryonal carcinomas showed no or very little expression, whereas yolk sac tumours strongly expressed HMGA2 at the transcriptome as well as the protein level. In teratomas, the expression varied and in choriocarcinomas the expression was moderate. In part, these results contradict data from previous studies but HMGA2 seems to represent a novel marker to assist pathological subtyping of testicular germ cell tumours. The results indicate a critical role in yolk sac tumours and some forms of teratoma. PMID:27499908

  19. Pathogenesis of germ cell neoplasia in testicular dysgenesis and disorders of sex development.

    PubMed

    Jørgensen, Anne; Lindhardt Johansen, Marie; Juul, Anders; Skakkebaek, Niels E; Main, Katharina M; Rajpert-De Meyts, Ewa

    2015-09-01

    Development of human gonads is a sex-dimorphic process which evolved to produce sex-specific types of germ cells. The process of gonadal sex differentiation is directed by the action of the somatic cells and ultimately results in germ cells differentiating to become functional gametes through spermatogenesis or oogenesis. This tightly controlled process depends on the proper sequential expression of many genes and signalling pathways. Disturbances of this process can be manifested as a large spectrum of disorders, ranging from severe disorders of sex development (DSD) to - in the genetic male - mild reproductive problems within the testicular dysgenesis syndrome (TDS), with large overlap between the syndromes. These disorders carry an increased but variable risk of germ cell neoplasia. In this review, we discuss the pathogenesis of germ cell neoplasia associated with gonadal dysgenesis, especially in individuals with 46,XY DSD. We summarise knowledge concerning development and sex differentiation of human gonads, with focus on sex-dimorphic steps of germ cell maturation, including meiosis. We also briefly outline the histopathology of germ cell neoplasia in situ (GCNIS) and gonadoblastoma (GDB), which are essentially the same precursor lesion but with different morphological structure dependent upon the masculinisation of the somatic niche. To assess the risk of germ cell neoplasia in different types of DSD, we have performed a PubMed search and provide here a synthesis of the evidence from studies published since 2006. We present a model for pathogenesis of GCNIS/GDB in TDS/DSD, with the risk of malignancy determined by the presence of the testis-inducing Y chromosome and the degree of masculinisation. The associations between phenotype and the risk of neoplasia are likely further modulated in each individual by the constellation of the gene polymorphisms and environmental factors.

  20. Lactate Regulates Rat Male Germ Cell Function through Reactive Oxygen Species

    PubMed Central

    Galardo, María Noel; Regueira, Mariana; Riera, María Fernanda; Pellizzari, Eliana Herminia; Cigorraga, Selva Beatriz; Meroni, Silvina Beatriz

    2014-01-01

    Besides giving structural support, Sertoli cells regulate the fate of germ cells by supplying a variety of factors. These factors include hormones, several pro- and anti-apoptotic agents and also energetic substrates. Lactate is one of the compounds produced by Sertoli cells, which is utilized as an energetic substrate by germ cells, particularly spermatocytes and spermatids. Beyond its function as an energy source, some studies have proposed a role of lactate in the regulation of gene expression not strictly related to the energetic state of the cells. The general hypothesis that motivated this investigation was that lactate affects male germ cell function, far beyond its well-known role as energetic substrate. To evaluate this hypothesis we investigated: 1) if lactate was able to regulate germ cell gene expression and if reactive oxygen species (ROS) participated in this regulation, 2) if different signal transduction pathways were modified by the production of ROS in response to lactate and 3) possible mechanisms that may be involved in lactate stimulation of ROS production. In order to achieve these goals, cultures of germ cells obtained from male 30-day old rats were exposed to 10 or 20 mM lactate. Increases in lactate dehydrogenase (LDH) C and monocarboxylate transporter (MCT)2 expression, in Akt and p38-MAPK phosphorylation levels and in ROS production were observed. These effects were impaired in the presence of a ROS scavenger. Lactate stimulated ROS production was also inhibited by a LDH inhibitor or a NAD(P)H oxidase (NOX) inhibitor. NOX4 expression was identified in male germ cells. The results obtained herein are consistent with a scenario where lactate, taken up by germ cells, becomes oxidized to pyruvate with the resultant increase in NADH, which is a substrate for NOX4. ROS, products of NOX4 activity, may act as second messengers regulating signal transduction pathways and gene expression. PMID:24498241

  1. Model of the biotic cycle "plants germs - microorganisms" by affect heavy metal salts

    NASA Astrophysics Data System (ADS)

    Pisman, Tamara

    The growth of wheat germ roots exposed to heavy metal salts (ZnSO4) was studied experimentally and theoretically. During the experiment the plant seeds were preliminarily treated with an experimental microbial association. As a result, data were obtained about the decrease of the inhibiting effect of zinc on the growth of wheat germ roots where the seeds had been treated with the microbial association. To understand such effect, calculations were made to reveal the specific growth rate of a germ root depending on the inhibitor concentration with and without microorganism association treatment. It was shown that in case with the wheat germ roots the seeds of which had been treated with the microorganisms the inhibition constant (kI = 45 MPC (Maximum Permissible Concentration) was higher than in the case with the roots growing out of the seeds that hadn't been treated with the microorganisms (kI = 32 MPC). One of possible reasons for the decrease of growth inhibition of wheat germ roots by zinc salt is the protective function of microorganism's treatment of the seeds. To verify and confirm the experimental results, a mathematical model was created imitating the interaction between wheat germ roots and microbial association exposed to an inhibitor. Investigation of the model proved that the microbial association has a positive effect on the growth of wheat germ roots exposed to an inhibitor. The experimental and theoretical results agreed quantitatively. It was found out that the increase of the inhibitor concentration led to the effect of maximum relief of zinc inhibiting impact. The work is supported by grants Yenissei 07-04-96806.

  2. Loss of Sertoli-germ cell adhesion determines the rapid germ cell elimination during the seasonal regression of the seminiferous epithelium of the large hairy armadillo Chaetophractus villosus.

    PubMed

    Luaces, Juan Pablo; Rossi, Luis Francisco; Sciurano, Roberta Beatriz; Rebuzzini, Paola; Merico, Valeria; Zuccotti, Maurizio; Merani, Maria Susana; Garagna, Silvia

    2014-03-01

    The armadillo Chaetophractus villosus is a seasonal breeder whose seminiferous epithelium undergoes rapid regression with massive germ cell loss, leaving the tubules with only Sertoli cells and spermatogonia. Here, we addressed the question of whether this regression entails 1) the disassembly of cell junctions (immunolocalization of nectin-3, Cadm1, N-cadherin, and beta-catenin, and transmission electron microscopy [TEM]); 2) apoptosis (immunolocalization of cytochrome c and caspase 3; TUNEL assay); and 3) the involvement of Sertoli cells in germ cell phagocytosis (TEM). We showed a dramatic reduction in the extension of vimentin filaments associated with desmosomelike junctions at the interface between Sertoli and germ cells, and an increased diffusion of the immunosignals of nectin-3, Cadm1, N-cadherin, and beta-catenin. Together, these results suggest loss of Sertoli-germ cell adhesion, which in turn might determine postmeiotic cell sloughing at the beginning of epithelium regression. Then, loss of Sertoli-germ cell adhesion triggers cell death. Cytochrome c is released from mitochondria, but although postmeiotic cells were negative for late apoptotic markers, at advanced regression spermatocytes were positive for all apoptotic markers. Transmission electron microscopy analysis showed cytoplasmic engulfment of cell debris and lipid droplets within Sertoli cells, a sign of their phagocytic activity, which contributes to the elimination of the residual meiocytes still present in the latest regression phases. These findings are novel and add new players to the mechanisms of seminiferous epithelium regression occurring in seasonal breeders, and they introduce the armadillo as an interesting model for studying seasonal spermatogenesis. PMID:24451984

  3. In vitro differentiation of human tooth germ stem cells into endothelial- and epithelial-like cells.

    PubMed

    Doğan, Ayşegül; Demirci, Selami; Şahin, Fikrettin

    2015-01-01

    Current clinical techniques in dental practice include stem cell and tissue engineering applications. Dental stem cells are promising primary cell source for mainly tooth tissue engineering. Interaction of mesenchymal stem cell with epithelial and endothelial cells is strictly required for an intact tooth morphogenesis. Therefore, it is important to investigate whether human tooth germ stem cells (hTGSCs) derived from wisdom tooth are suitable for endothelial and epithelial cell transformation in dental tissue regeneration approaches. Differentiation into endothelial and epithelial cell lineages were mimicked under defined conditions, confirmed by real time PCR, western blotting and immunocytochemical analysis by qualitative and quantitative methods. HUVECs and HaCaT cells were used as positive controls for the endothelial and epithelial differentiation assays, respectively. Immunocytochemical and western blotting analysis revealed that terminally differentiated cells expressed cell-lineage markers including CD31, VEGFR2, VE-Cadherin, vWF (endothelial cell markers), and cytokeratin (CK)-17, CK-19, EpCaM, vimentin (epithelial cell markers) in significant levels with respect to undifferentiated control cells. Moreover, high expression levels of VEGFR1, VEGFR2, VEGF, CK-18, and CK-19 genes were detected in differentiated endothelial and epithelial-like cells. Endothelial-like cells derived from hTGSCs were cultured on Matrigel, tube-like structure formations were followed as an indication for functional endothelial differentiation. hTGSCs successfully differentiate into various cell types with a broad range of functional abilities using an in vitro approach. These findings suggest that hTGSCs may serve a potential stem cell source for tissue engineering and cell therapy of epithelial and endothelial tissue.

  4. Development of a Risk Stratification System to Guide Treatment for Female Germ Cell Tumors

    PubMed Central

    Meisel, Jane L.; Woo, Kaitlin M.; Sudarsan, Nora; Eng, Jana; Patil, Sujata; Jacobsen, Erin P.; Murali, Rajmohan; Gardner, Ginger J.; Bosl, George J.; Aghajanian, Carol; Feldman, Darren R.

    2016-01-01

    Objective Due to their rarity, little is known about prognostic factors in female germ cell tumors (GCTs) or outcomes following systemic therapy. Management is largely based on studies of male GCT and epithelial ovarian cancer. Methods Chart review was performed for all females with GCT seen at Memorial Sloan Kettering Cancer Center (MSKCC) from 1990 to 2012. Patients receiving chemotherapy were stratified using a modification of the male IGCCCG risk system, and the classifier was correlated with outcome. Results Of 93 patients, 92 (99%) underwent primary surgery and 85 (92%) received chemotherapy. Modified IGCCCG classification was significantly associated with progression-free survival (PFS) and overall survival (OS), both when applied preoperatively and pre-chemotherapy (p<0.001 for all four analyses). Progression after initial chemotherapy (n=29) was detected by imaging in 14 (48%) patients, by serum tumor markers in 6 (21%) patients, and by multiple methods in the rest. Seven (29%) of 24 patients treated with salvage chemotherapy achieved long-term PFS, including 4/6 who received high-dose chemotherapy (HDCT) as initial salvage versus 3/16 treated with other initial salvage regimens. The estimated 3-year OS rate was 84% (95% CI, 76-92%), with a trend favoring dysgerminoma over non-dysgerminoma histologies (p=0.12). Conclusions Modified IGCCCG classification was prognostic for female GCT patients in this cohort and identified a poor-risk group who may benefit from more intensive first-line chemotherapy. Both imaging and tumor marker evaluation were important in identifying relapses after first-line chemotherapy. The majority of long-term remissions with salvage therapy were achieved with initial salvage HDCT. PMID:26115974

  5. Sequence-dependent but not sequence-specific piRNA adhesion traps mRNAs to the germ plasm

    PubMed Central

    Vrettos, Nicholas; Maragkakis, Manolis; Mourelatos, Zissimos

    2016-01-01

    The conserved Piwi family of proteins and piwi-interacting RNAs (piRNAs) play a central role in genomic stability, which is inextricably tied with germ cell formation, by forming ribonucleoproteins (piRNPs) that silence transposable elements (TEs)1. In Drosophila melanogaster and other animals, primordial germ cell (PGC) specification in the developing embryo is driven by maternal mRNAs and proteins that assemble into specialized mRNPs localized in the germ (pole) plasm at the posterior of the oocyte2,3. Maternal piRNPs, especially those loaded on Aubergine (Aub), a Piwi protein, are transmitted to the germ plasm to initiate transposon silencing in the offspring germline4–7. Transport of mRNAs to the oocyte by midoogenesis is an active, microtubule-dependent process8; mRNAs necessary for PGC formation are enriched in the germ plasm at late oogenesis via a diffusion and entrapment mechanism, whose molecular identity remains unknown8,9. Aub is a central component of germ granule RNPs, which house mRNAs in the germ plasm10–12 and interactions between Aub and Tudor are essential for the formation of germ granules13–16. Here we show that Aub-loaded piRNAs use partial base pairing characteristic of Argonaute RNPs to bind mRNAs randomly, acting as an adhesive trap that captures mRNAs in the germ plasm, in a Tudor-dependent manner. Strikingly, germ plasm mRNAs in Drosophilids are generally longer and more abundant than other mRNAs, suggesting that they provide more target sites for piRNAs to promote their preferential tethering in germ granules. Thus complexes containing Tudor, Aub piRNPs and mRNAs couple piRNA inheritance with germline specification. Our findings reveal an unexpected function for Piwi ribonucleoprotein complexes in mRNA trapping that may be generally relevant to the function of animal germ granules. PMID:26950602

  6. The Mouse Fetal Ovary Has Greater Sensitivity Than the Fetal Testis to Benzo[a]pyrene-Induced Germ Cell Death.

    PubMed

    Lim, Jinhwan; Kong, Weixi; Lu, Muzi; Luderer, Ulrike

    2016-08-01

    The polycyclic aromatic hydrocarbon pollutant benzo[a]pyrene (BaP) is a known developmental gonadotoxicant. However, the mechanism of BaP-induced germ cell death is unclear. We investigated whether exposure to BaP induces apoptotic germ cell death in the mouse fetal ovary or testis. Mouse fetal gonads were dissected at embryonic day 13.5 days postcoitum (dpc) and fixed immediately or cultured for 6, 24, 48, or 72 h with various concentrations of BaP (1-1000 ng/ml). Germ cells numbers, apoptosis, and proliferation were evaluated by immunostaining. Treatment of fetal ovaries with BaP for 72 h concentration-dependently depleted germ cells. Treatment with BaP elevated the expression of BAX protein at 6 h and activated downstream caspases-9 and -3 at 24 h in a concentration-dependent manner in germ cells of fetal ovaries. As a consequence, ovarian germ cell numbers were significantly and concentration-dependently decreased at 48 h. Pretreatment with z-VAD-fmk, a pan-caspase inhibitor, prior to exposure to 1000 ng/ml BaP prevented BaP-mediated ovarian germ cell death; there were no effects of BaP or z-VAD-fmk on germ cell proliferation. No significant effects of BaP exposure on caspase 3 activation or germ cell numbers were observed in fetal testes after 48 h of culture. Our findings show that BaP exposure increases caspase-dependent and BAX-associated germ cell apoptosis in the mouse fetal ovary, leading to germ cell depletion. In contrast, the cultured 13.5 dpc fetal testis is relatively resistant to BaP-induced germ cell death. This study provides a novel insight into molecular mechanisms by which BaP has direct gonadotoxicity in the mouse fetal ovary. PMID:27208085

  7. Production of chicken progeny (Gallus gallus domesticus) from interspecies germline chimeric duck (Anas domesticus) by primordial germ cell transfer.

    PubMed

    Liu, Chunhai; Khazanehdari, Kamal A; Baskar, Vijaya; Saleem, Shazia; Kinne, Joerg; Wernery, Ulrich; Chang, Il-Kuk

    2012-04-01

    The present study aimed to investigate the differentiation of chicken (Gallus gallus domesticus) primordial germ cells (PGCs) in duck (Anas domesticus) gonads. Chimeric ducks were produced by transferring chicken PGCs into duck embryos. Transfer of 200 and 400 PGCs resulted in the detection of a total number of 63.0 ± 54.3 and 116.8 ± 47.1 chicken PGCs in the gonads of 7-day-old duck embryos, respectively. The chimeric rate of ducks prior to hatching was 52.9% and 90.9%, respectively. Chicken germ cells were assessed in the gonad of chimeric ducks with chicken-specific DNA probes. Chicken spermatogonia were detected in the seminiferous tubules of duck testis. Chicken oogonia, primitive and primary follicles, and chicken-derived oocytes were also found in the ovaries of chimeric ducks, indicating that chicken PGCs are able to migrate, proliferate, and differentiate in duck ovaries and participate in the progression of duck ovarian folliculogenesis. Chicken DNA was detected using PCR from the semen of chimeric ducks. A total number of 1057 chicken eggs were laid by Barred Rock hens after they were inseminated with chimeric duck semen, of which four chicken offspring hatched and one chicken embryo did not hatch. Female chimeric ducks were inseminated with chicken semen; however, no fertile eggs were obtained. In conclusion, these results demonstrated that chicken PGCs could interact with duck germinal epithelium and complete spermatogenesis and eventually give rise to functional sperm. The PGC-mediated germline chimera technology may provide a novel system for conserving endangered avian species.

  8. Environmental Tobacco Smoke Exposure during Intrauterine Period, Promotes Caspase Dependent and Independent DNA Fragmentation in Sertoli-Germ Cells

    PubMed Central

    Yüksel, Beril; Kilic, Sevtap; Lortlar, Nese; Tasdemir, Nicel; Sertyel, Semra; Bardakci, Yesim; Aksu, Tarik; Batioglu, Sertaç

    2014-01-01

    Objectives. To investigate the effect of cigarette smoke exposure during intrauterine period on neonatal rat testis. Methods. Twenty-five rats were randomized to be exposed to cigarette smoke with the Walton Smoking Machine or to room air during their pregnancies. The newborn male rats (n = 21) were grouped as group 1 (n = 15) which were exposed to cigarette smoke during intrauterine life and group 2 (n = 6) which were exposed to room air during intrauterine life. The orchiectomy materials were analyzed with TUNEL immunofluorescent staining for detection of DNA damage. To detect apoptosis, immunohistochemical analyses with caspase-3 were performed. Primary outcomes were apoptotic index and immunohistochemical scores (HSCORES); secondary outcomes were Sertoli-cell count and birth-weight of rats. Results. Sertoli cell apoptosis was increased in group 1 (HSCORE = 210.6 ± 41.9) when compared to group 2 (HSCORE = 100.0 ± 17.8) (P = 0.001). Sertoli cell count was decreased in group 1 (P = 0.043). The HSCORE for the germ cells was calculated as 214.0 ± 46.2 in group 1 and 93.3 ± 10.3 in group 2 (P = 0.001) referring to an increased germ cell apoptosis in group 1. The apoptotic indexes for group 1 were 49.6 ± 9.57 and 29.98 ± 2.34 for group 2 (P = 0.001). The immunofluorescent technique demonstrated increased DNA damage in seminiferous epithelium in group 1. Conclusions. Intrauterine exposure to cigarette smoke adversely affects neonatal testicular structuring and diminishes testicular reserve. PMID:25045542

  9. Similar synapse density in layer IV columns of the primary somatosensory cortex of transgenic mice with different brain size: implications for mechanisms underlying the differential allocation of cortical space.

    PubMed

    Gutiérrez-Ospina, Gabriel; Uribe-Querol, Eileen; Sánchez, Norma; Geovannini, Helga; Padilla, Patricia; Hernández-Echeagaray, Elizabeth

    2004-01-01

    The relative dimension of the areas constituting the cerebral cortex differs greatly in the brains of different mammalian species. The mechanisms by which such an evolutionary remodeling has occurred is not well understood. To begin exploring possible mechanisms, we took advantage of a transgenic mouse model in which the area of the primary somatosensory cortex (S1) shifts, to some extent independent from the area of the cortex as a whole, as a result of differences in the availability of insulin-like growth factor I (IGF-I). Electron microscopy estimations of synapse density in D3 and C3 cortical columns of the S1 layer IV revealed that this parameter was similar among wild type and transgenic mice with higher and lower availability of IGF-I. Because D3 and C3 columns were larger and smaller than normal in mice with higher and lower IGF-I availability, the total number of synapses contained in the average area of D3 and C3 columns increased and decreased, respectively. No differences in the number and overall arrangement of S1 columns were observed among animal groups. These results suggest that: 1) synapse density is a constant factor within the S1 cortical column structure; 2) the mechanisms and factors regulating cell number and synaptogenesis are affected as columns and cortical areas modify their relative dimensions; 3) altered availability of neurotrophic factors might be associated with changes in areal dimensions; and 4) changes in cortical areal dimensions within single lineages might result from the addition of minicolumns to preexisting columns.

  10. Mechanism of neutrophil chemiluminescence induced by wheat germ agglutinin: partial characterization of the antigens recognized by wheat germ agglutinin

    SciTech Connect

    Ozaki, Y.; Iwata, J.; Ohashi, T.

    1984-11-01

    Wheat germ agglutinin (WGA) stimulated neutrophils to produce significant levels of luminol-dependent chemiluminescence (CL). Since WGA is known to bind N-acetylglucosamine (GlcNAc) oligomers and N-acetylneuraminic acid (NANA), we attempted to determine which binding property of WGA is essential for induction of CL. The succinylated form of WGA (SuWGA), which is no longer able to bind NANA, was still able to induce CL. N-Acetylglucosamine at a concentration of 20 mmol/L almost completely inhibited WGA-induced CL production by neutrophils, whereas bovine submaxillary gland mucin, a potent blocker of NANA binding of WGA, failed to inhibit CL production. Lectins with the GlcNAc-binding property were examined for their ability to induce CL. Those that have higher valences and have a tendency to bind GlcNAc oligomers in the internal portion of glycoconjugates were able to induce CL, whereas those that have low valences and bind terminal GlcNAc of glycoconjugates failed to induce CL even at high concentrations. Attempts were made to characterize the neutrophil membrane proteins recognized by WGA. Glycoproteins with a molecular weight of 25,000 daltons were identified by a 50 mmol/L GlcNAc elution of WGA gels loaded with /sup 125/I-labeled neutrophil membrane proteins. Elution with 500 mumol/L GlcNAc trimer produced several glycoproteins of different molecular weights in addition to the glycoproteins of 25,000 daltons. /sup 125/I-labeled WGA and SuWGA were used for autoradiographic analysis of cell extracts of the neutrophils separated on sodium dodecyl sulfate polyacrylamide gels. WGA recognized multiple glycoproteins of different molecular weights, whereas SuWGA bound only a few of them. Glycoproteins of 25,000 daltons, probably corresponding to those identified by 50 mmol/L GlcNAc elution, were also recognized.

  11. Exogenous supplementation of Activin A enhances germ cell differentiation of human embryonic stem cells.

    PubMed

    Duggal, Galbha; Heindryckx, Björn; Warrier, Sharat; Taelman, Jasin; Van der Jeught, Margot; Deforce, Dieter; Chuva de Sousa Lopes, Susana; De Sutter, Petra

    2015-05-01

    Human embryonic stem cells (hESCs) derived in the presence of Activin A (ActA) demonstrate an increased differentiation propensity toward the germ cell lineage. In addition, mouse epiblast stem cells and mouse epiblast-like cells are poised toward germ cell differentiation and are derived in the presence of ActA. We therefore investigated whether supplementation with ActA enhances in vitro hESC differentiation toward germ cell lineage. ActA up-regulated early primordial germ cell (PGC) genes STELLA/DPPA3 (developmental pluripotency associated 3) and tyrosine kinase receptor cKIT in both ActA-derived and standard-derived hESCs indicating its role in priming hESCs toward the PGC lineage. Indeed, ActA plus bone morphogenic protein 4 (BMP4) strongly increased germ cell differentiation potential of hESCs based on the high expression of late PGC markers DAZL (deleted in azoospermia-like) and VASA/DDX4 (DEAD-box polypeptide 4) at mRNA and protein level. Hence, the combination of ActA with BMP4 provides an additional boost for hESCs to develop into postmigratory germ cells. Together with increased VASA expression in the presence of ActA and BMP4, we also observed up-regulation of endoderm-specific genes GATA4 (GATA binding protein 4) and GATA6. Finally, we were able to further mature these in vitro-derived PGC-like cells (PGCLCs) by culturing them in in vitro maturation (IVM) medium, resulting in the formation of germ cell-like clusters and induction of meiotic gene expression. In conclusion, we demonstrate for the first time a synergism between ActA and BMP4 in facilitating germ cell-directed differentiation of hESCs, which is enhanced by extended culture in IVM medium, as shown by cytoplasmic VASA-expressing PGCLCs. We propose a novel relationship between the endoderm and germ cell lineage during hESC differentiation.

  12. Gender differences in the induction of chromosomal aberrations and gene mutations in rodent germ cells

    SciTech Connect

    Adler, Ilse-Dore; Carere, Angelo; Eichenlaub-Ritter, Ursula

    2007-05-15

    Germ cell mutagenicity testing provides experimental data to quantify genetic risk for exposed human populations. The majority of tests are performed with exposure of males, and female data are relatively rare. The reason for this paucity lies in the differences between male and female germ cell biology. Male germ cells are produced throughout reproductive life and all developmental stages can be ascertained by appropriate breeding schemes. In contrast, the female germ cell pool is limited, meiosis begins during embryogenesis and oocytes are arrested over long periods of time until maturation processes start for small numbers of oocytes during the oestrus cycle in mature females. The literature data are reviewed to point out possible gender differences of germ cells to exogenous agents such as chemicals or ionizing radiation. From the limited information, it can be concluded that male germ cells are more sensitive than female germ cells to the induction of chromosomal aberrations and gene mutations. However, exceptions are described which shed doubt on the extrapolation of experimental data from male rodents to the genetic risk of the human population. Furthermore, the female genome may be more sensitive to mutation induction during peri-conceptional stages compared to the male genome of the zygote. With few exceptions, germ cell experiments have been carried out under high acute exposure to optimize the effects and to compensate for the limited sample size in animal experiments. Human exposure to environmental agents, on the other hand, is usually chronic and involves low doses. Under these conditions, gender differences may become apparent that have not been studied so far. Additionally, data are reviewed that suggest a false impression of safety when responses are negative under high acute exposure of male rodents while a mutational response is induced by low chronic exposure. The classical (morphological) germ cell mutation tests are not performed anymore

  13. Germ cell degeneration in high-temperature treated pufferfish, Takifugu rubripes.

    PubMed

    Lee, K H; Yamaguchi, A; Rashid, H; Kadomura, K; Yasumoto, S; Matsuyama, M

    2009-01-01

    Exogenous factors such as temperature, social behavior, and salinity play a crucial role during the critical sensitive period of sex differentiation in many vertebrates. In fishes, amphibians, and reptiles temperature treatment is known to induce all-male (or female) individuals, and genes related to sex differentiation have been studied. The Japanese pufferfish, Takifugu rubripes, possesses the most compact genome among vertebrates and has immense potential for studies focusing on comparative genome analysis. In this study, we describe gonadal morphology and vasa (germ cell marker) and dmrt1 (Sertoli cell marker) expression on a molecular level in relation to the development of temperature-treated pufferfish. To investigate the relationship between temperature and gonadal development, pufferfish were exposed to high-temperature conditions (32 degrees C) during early gonadal development. Morphological observations showed that this high-temperature treatment did not influence sexual differentiation as determined by ovarian cavity characteristics; however, high-temperature treatment induces gonadal degeneration that is devoid of germ cells. RT-PCR results revealed no vasa expression within germ cell-degenerated gonads. In situ hybridization results showed that dmrt1 was expressed in somatic cells of germ cell-degenerated ovaries. These results suggest that high-temperature treatment during early gonadal development induces germ cell degeneration and masculinization of ovarian somatic cells in pufferfish.

  14. DDX4 (VASA) is conserved in germ cell development in marsupials and monotremes.

    PubMed

    Hickford, Danielle E; Frankenberg, Stephen; Pask, Andrew J; Shaw, Geoff; Renfree, Marilyn B

    2011-10-01

    DDX4 (VASA) is an RNA helicase expressed in the germ cells of all animals. To gain greater insight into the role of this gene in mammalian germ cell development, we characterized DDX4 in both a marsupial (the tammar wallaby) and a monotreme (the platypus). DDX4 is highly conserved between eutherian, marsupial, and monotreme mammals. DDX4 protein is absent from tammar fetal germ cells but is present from Day 1 postpartum in both sexes. The distribution of DDX4 protein during oogenesis and spermatogenesis in the tammar is similar to eutherians. Female tammar germ cells contain DDX4 protein throughout all stages of postnatal oogenesis. In males, DDX4 is in gonocytes, and during spermatogenesis it is present in spermatocytes and round spermatids. A similar distribution of DDX4 occurs in the platypus during spermatogenesis. There are several DDX4 isoforms in the tammar, resulting from both pre- and posttranslational modifications. DDX4 in marsupials and monotremes has multiple splice variants and polyadenylation motifs. Using in silico analyses of genomic databases, we found that these previously unreported splice variants also occur in eutherians. In addition, several elements implicated in the control of Ddx4 expression in the mouse, including RGG (arginine-glycine-glycine) and dimethylation of arginine motifs and CpG islands within the Ddx4 promoter, are also highly conserved. Collectively these data suggest that DDX4 is essential for the regulation of germ cell proliferation and differentiation across all three extant mammalian groups-eutherians, marsupials, and monotremes.

  15. Human iPS Cell-Derived Germ Cells: Current Status and Clinical Potential

    PubMed Central

    Ishii, Tetsuya

    2014-01-01

    Recently, fertile spermatozoa and oocytes were generated from mouse induced pluripotent (iPS) cells using a combined in vitro and in vivo induction system. With regard to germ cell induction from human iPS cells, progress has been made particularly in the male germline, demonstrating in vitro generation of haploid, round spermatids. Although iPS-derived germ cells are expected to be developed to yield a form of assisted reproductive technology (ART) that can address unmet reproductive needs, genetic and/or epigenetic instabilities abound in iPS cell generation and germ cell induction. In addition, there is still room to improve the induction protocol in the female germline. However, rapid advances in stem cell research are likely to make such obstacles surmountable, potentially translating induced germ cells into the clinical setting in the immediate future. This review examines the current status of the induction of germ cells from human iPS cells and discusses the clinical potential, as well as future directions. PMID:26237592

  16. Defective autophagy through epg5 mutation results in failure to reduce germ plasm and mitochondria.

    PubMed

    Herpin, Amaury; Englberger, Eva; Zehner, Mario; Wacker, Robin; Gessler, Manfred; Schartl, Manfred

    2015-10-01

    Autophagy is an evolutionarily conserved catabolic process that transports cytoplasmic components to lysosomes for degradation. In addition to the canonical view of strict stress-response-induced autophagy, selectively programmed autophagy was recently reported in the context of gonad development of flies and worms, where autophagy seems to be necessary for clearance of germ plasm components. Similar functions have not been described in vertebrates. We used the medaka fish to study the role of autophagy in gonad formation and gametogenesis for the first time in a vertebrate organism for which the germ line is specified by germ plasm. Using a transgenic line deficient in the Ol-epg5 gene—a new critical component of the autophagy pathway—we show that such deficiency leads to an impaired autophagic flux, possibly attributed to compromised maturation or processing of the autophagosomes. Ol-epg5 deficiency correlates with selectively impaired spermatogenesis and low allele transmission rates of the mutant allele caused by failure of germ plasm and mitochondria clearance during the process of germ cell specification and in the adult gonads. The mouse epg-5 homolog is similarly expressed in the maturating and adult testes, suggesting an at least partially conserved function of this process during spermatogenesis in vertebrates. PMID:26183773

  17. The Epigenetics of Germ-line Immortality: Lessons from an Elegant Model System

    PubMed Central

    Furuhashi, Hirofumi; Kelly, William G.

    2014-01-01

    Epigenetic mechanisms are thought to help regulate the unique transcription program that is established in germ cell development. During the germline cycle of many organisms, the epigenome undergoes waves of extensive resetting events, while a part of epigenetic modification remains faithful to specific loci. Little is known about the mechanisms underlying these events, how loci are selected for, or avoid, reprogramming, or even why these events are required. In particular, although the significance of genomic imprinting phenomena involving DNA methylation in mammals is now well accepted, the role of histone modification as a transgenerational epigenetic mechanism has been the subject of debate. Such epigenetic mechanisms may help regulate transcription programs and / or the pluripotent status conferred on germ cells, and contribute to germ line continuity across generations. Recent studies provide new evidence for heritability of histone modifications through germ line cells and its potential effects on transcription regulation both in the soma and germ line of subsequent generations. Unraveling transgenerational epigenetic mechanisms involving highly conserved histone modifications in elegant model systems will accelerate the generation of new paradigms and inspire research in a wide variety of fields, including basic developmental studies and clinical stem cell research. PMID:20646025

  18. Retroperitoneal metastatic germ cell tumor presenting as a psoas abscess: a diagnostic pitfall.

    PubMed

    Dieker, Carrie A; De Las Casas, Luis E; Davis, Brian R

    2013-07-01

    Most testicular neoplasms are germ cell tumors, the vast majority of which represent seminomas. Most seminomas present localized to the testis, whereas nonseminomatous germ cell tumors more often present with lymph node metastases. Psoas abscesses generally arise from a contiguous intra-abdominal or pelvic infectious process, an adjacent focus of osteomyelitis or septic emboli from distant infectious foci. In this study, the case of a 24-year-old man who presented with a right psoas mass presumptively diagnosed as an abscess secondary to fever and leukocytosis is presented. The patient had a history of right testicular seminoma, and normal serum levels of alpha-fetoprotein and human chorionic gonadotropin. Surgical exploration and biopsy demonstrated seminoma metastasis. This case represents an extremely unusual clinical presentation of metastatic germ cell tumor presenting as a psoas abscess. This unique case represents an unusual presentation of a recurrent germ cell tumor mimicking a psoas abscess. Awareness of possible metastatic testicular germ cell neoplasm as a psoas abscess could prevent diagnosis delay before retroperitoneal tumor debulking. PMID:23360792

  19. Ascorbic acid protects against cadmium-induced endoplasmic reticulum stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Zhen; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-11-01

    Cadmium (Cd) is a testicular toxicant which induces endoplasmic reticulum (ER) stress and germ cell apoptosis in testes. This study investigated the effects of ascorbic acid on Cd-evoked ER stress and germ cell apoptosis in testes. Male mice were intraperitoneally injected with CdCl(2) (2.0 mg/kg). As expected, a single dose of Cd induced testicular germ cell apoptosis. Interestingly, Cd-triggered testicular germ cell apoptosis was almost completely inhibited in mice treated with ascorbic acid. Interestingly, ascorbic acid significantly attenuated Cd-induced upregulation of GRP78 in testes. In addition, ascorbic acid significantly attenuated Cd-triggered testicular IRE1α and eIF2α phosphorylation and XBP-1 activation, indicating that this antioxidant counteracts Cd-induced unfolded protein response (UPR) in testes. Finally, ascorbic acid significantly attenuated Cd-evoked upregulation of CHOP and JNK phosphorylation, two components in ER stress-mediated apoptotic pathway. In conclusion, ascorbic acid protects mice from Cd-triggered germ cell apoptosis via inhibiting ER stress and UPR in testes. PMID:22569276

  20. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies.

    PubMed

    Dominguez, Antonia A; Chiang, H Rosaria; Sukhwani, Meena; Orwig, Kyle E; Reijo Pera, Renee A

    2014-09-22

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood.

  1. Dazl is a target RNA suppressed by mammalian NANOS2 in sexually differentiating male germ cells

    PubMed Central

    Kato, Yuzuru; Katsuki, Takeo; Kokubo, Hiroki; Masuda, Aki; Saga, Yumiko

    2016-01-01

    Evolutionally conserved Nanos RNA-binding proteins play crucial roles in germ cell development. While a mammalian Nanos family protein, NANOS2, is required for sexual differentiation of male (XY) germ cells in mice, the underlying mechanisms and the identities of its target RNAs in vivo remain elusive. Using comprehensive microarray analysis and a bacterial artificial chromosome transgenic system, here we identify Dazl, a germ cell-specific gene encoding an RNA-binding protein implicated in translation, as a crucial target of NANOS2. Importantly, removal of the Dazl 3′-untranslated region in XY germ cells stabilizes the Dazl mRNA, resulting in elevated meiotic gene expression, abnormal resumption of the cell cycle and impaired processing-body formation, reminiscent of Nanos2-knockout phenotypes. Furthermore, our data suggest that NANOS2 acts as an antagonist of the DAZL protein. We propose a dual system of NANOS2-mediated suppression of Dazl expression as a pivotal molecular mechanism promoting sexual differentiation of XY germ cells. PMID:27072294

  2. Independent and coordinate trafficking of single Drosophila germ plasm mRNAs

    PubMed Central

    Little, Shawn C.; Sinsimer, Kristina S.; Lee, Jack J.; Wieschaus, Eric F.; Gavis, Elizabeth R.

    2015-01-01

    mRNA localization is a conserved mechanism for spatial control of protein synthesis, with key roles in generating cellular and developmental asymmetry. While different transcripts may be targeted to the same subcellular domain, the extent to which their localization is coordinated is unclear. Using quantitative single molecule imaging, we analyzed the assembly of Drosophila germ plasm mRNA granules inherited by nascent germ cells. We find that the germ cell-destined transcripts nanos, cyclin B, and polar granule component travel within the oocyte as ribonucleoprotein particles containing single mRNA molecules but co-assemble into multi-copy heterogeneous granules selectively at the posterior of the oocyte. The stoichiometry and dynamics of assembly indicate a defined stepwise sequence. Our data suggest that co-packaging of these transcripts ensures their effective segregation to germ cells. In contrast, compartmentalization of the germline determinant oskar mRNA into different granules limits its entry into germ cells. This exclusion is required for proper germline development. PMID:25848747

  3. Dazl is a target RNA suppressed by mammalian NANOS2 in sexually differentiating male germ cells.

    PubMed

    Kato, Yuzuru; Katsuki, Takeo; Kokubo, Hiroki; Masuda, Aki; Saga, Yumiko

    2016-01-01

    Evolutionally conserved Nanos RNA-binding proteins play crucial roles in germ cell development. While a mammalian Nanos family protein, NANOS2, is required for sexual differentiation of male (XY) germ cells in mice, the underlying mechanisms and the identities of its target RNAs in vivo remain elusive. Using comprehensive microarray analysis and a bacterial artificial chromosome transgenic system, here we identify Dazl, a germ cell-specific gene encoding an RNA-binding protein implicated in translation, as a crucial target of NANOS2. Importantly, removal of the Dazl 3'-untranslated region in XY germ cells stabilizes the Dazl mRNA, resulting in elevated meiotic gene expression, abnormal resumption of the cell cycle and impaired processing-body formation, reminiscent of Nanos2-knockout phenotypes. Furthermore, our data suggest that NANOS2 acts as an antagonist of the DAZL protein. We propose a dual system of NANOS2-mediated suppression of Dazl expression as a pivotal molecular mechanism promoting sexual differentiation of XY germ cells. PMID:27072294

  4. The degenerative fate of germ cells not conforming to stage in the pubertal golden hamster testis.

    PubMed

    Miething, A

    1998-11-01

    In the golden hamster (Mesocricetus auratus), pubertal establishment of spermatogenesis includes a defined period (d 26-30 of life) during which elongation of spermatids is selectively arrested. The resulting appearance of germ cell associations not conforming to stage and the phenomenon of desynchronisation-related germ cell degeneration are analysed both quantitatively and qualitatively by means of light and 'retrospective' electron microscopy. From d 26 onwards, the portion of tubules containing non-stage conforming germ cell associations gradually increases up to 37.5% of sectioned tubules on d 32. Concomitantly, the degree of desynchronisation rises to a maturational gap between spermatids and associated younger germ cells of 7 stages of the seminiferous epithelium cycle, i.e. of fully half a cycle. Beyond d 32, the frequency of desynchronised tubule segments decreases again. Some of the arrested round spermatids and, eventually, all belatedly elongating spermatids degenerate and are lost from the epithelium. Thus a regular maturation of advanced spermatids does not succeed under non-stage conforming conditions. Possibly it is not the desynchronisation between the associated germ cell generations and the spermatids by itself that impedes normal further development of the latter cells. Instead this may be due to the maturational delay of the stage-aberrant cells by several stages compared to the seminiferous epithelium as a whole and, especially, in relation to the stage-conditioned functional state of the neighbouring Sertoli cells.

  5. Toll-like receptor 11-initiated innate immune response in male mouse germ cells.

    PubMed

    Chen, Qiaoyuan; Zhu, Weiwei; Liu, Zhenghui; Yan, Keqin; Zhao, Shutao; Han, Daishu

    2014-02-01

    Toxoplasma gondii and uropathogenic Escherichia coli (UPEC) may infect the testis and impair testicular function. Mechanisms underlying testicular innate immune response to these two pathogens remain to be clarified. The present study examined the function of TLR11, which can be recognized by T. gondii-derived profilin and UPEC, in initiating innate immune response in male mouse germ cells. TLR11 is predominantly expressed in spermatids. Profilin and UPEC induced the expressions of different inflammatory cytokine profiles in the germ cells. In particular, profilin induced the expressions of macrophage chemotactic protein 1 (MCP1), interleukin 12 (IL12), and interferon gamma (IFNG) through nuclear factor KB (NFKB) activation. UPEC induced the expressions of MCP1, IL12, and IFNG, as well as tumor necrosis factor alpha (TNFA), IL6, and IFNB, through the activation of NFKB, IFN regulatory factor 3, and mitogen-activated protein kinases. Evidence showed that profilin induced the innate response in male germ cells through TLR11 signaling, and UPEC triggered the response through TLR11 and other TLR-signaling pathways. We also provided evidence that local injection of profilin or UPEC induces the innate immune response in the germ cells. Data describe TLR11-mediated innate immune function of male germ cells in response to T. gondii profilin and UPEC stimulations. This system may play a role in testicular defense against T. gondii and UPEC infections in mice.

  6. Migratory mechanisms of chick primordial germ cells toward gonadal anlage.

    PubMed

    Kuwana, T; Rogulska, T

    1999-07-01

    After appearing at the germinal crescent region, chick primordial germ cells (PGCs) migrate toward the presumptive gonads (pG) till stage 19 (Hamburger and Hamilton, 1951). This study seeks to elucidate the roles of passive and active factors in the PGC-migration, physical trapping of circulating PGCs by the capillary network and PGC attraction by chemotactic factor from presumptive gonads. Firstly, latex beads/pollens (the same size or larger than PGCs) were injected into the embryonic bloodstream at stage 13-19 (when PGCs are in the migrating and settlement phase to the presumptive gonad) in ovo in order to determine whether the PGCs passively reach pG. Most of such particles accumulated in the head region (60%), whereas the remainder did the same in the gonadal region (23% at the peak) at stage 16 when both the head and gonadal regions are rich in capillary plexus. After 3 days, most particles in the gonadal region were located at the angles of dorsal mesentery near the developing gonads where many extra-gonadal PGCs had been located, and a few particles were detected close to the gonad. These results suggest that one of the mechanisms of PGC-migration to the developing gonads is an autonomous trapping of PGCs by the capillary network quite close to the germinal epithelium (GE) and passive translocation by morphogenetic movement. Secondly, the attraction for PGCs by the gonadal anlage proper was examined in ovo using chick and quail embryos. Grafts of quail gonadal anlage containing gonadal epithelium and neighbouring mesenchymal tissue were excised from the quail embryo at stages 12 to 16 (staging by Zacchei, 1961). With the aims of eliminating the influence of surrounding tissue, the quail graft was ectopically transplanted into the posterior to the optic vesicle of 8 to 17 somite chick embryo from the point of a posterior region to the auditory vesicle by a fine tungsten needle under the illumination by the method of Hara (1971). Then the region posterior to

  7. Sequential resection of residual abdominal and thoracic masses after chemotherapy for metastatic non-seminomatous germ cell tumours.

    PubMed Central

    Gerl, A.; Clemm, C.; Schmeller, N.; Dienemann, H.; Weiss, M.; Kriegmair, M.; Löhrs, U.; Wilmanns, W.

    1994-01-01

    Thirty-eight patients with advanced non-seminomatous germ cell tumours (NSGCTs) underwent multiple surgical interventions (two in 33 patients, three in four patients, four in one patient) after cisplatin-based chemotherapy. All patients had normal serum tumour markers but persistent radiographic masses. The larger mass was routinely resected first. Fifteen patients (39%) had dissimilar histological findings at sequential surgical procedures, 12 of whom demonstrated less favourable pathological features during the first operation and three at the second. Patients who underwent both retroperitoneal lymph node dissection (RPLND) and lung resection showed less favourable histological features in the retroperitoneum in nine cases and in the lung in three cases. Eight of 16 patients (50%) without mature teratoma in their primary tumours showed complete necrosis/fibrosis at all surgical interventions, whereas all patients whose primary tumour was classified as malignant teratoma intermediate demonstrated mature teratoma at least at one anatomical site. As histology of post-chemotherapy residual masses cannot be extrapolated from one anatomical site to another, patients usually are properly managed by excision of all residual masses. In particular, in patients with necrosis/fibrosis at lung resection omission of RPLND is not advised. PMID:7524606

  8. Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

    SciTech Connect

    Yamano, Noriko; Kimura, Tohru; Watanabe-Kushima, Shoko; Shinohara, Takashi; Nakano, Toru

    2010-02-12

    Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were cultured on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.

  9. New perspective on molecular markers as promising therapeutic targets in germ cell tumors

    PubMed Central

    Chieffi, Paolo

    2016-01-01

    Summary Testicular germ cell tumors (TGCTs) are the most frequent solid malignant tumors in men 20–40 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs comprise two major histologic groups: seminomas and non-seminomas germ cell tumors (NSGCTs). NSGCTs can be further divided into embryonal carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). Many discovered biomarkers including HMGA1, GPR30, Aurora-B, estrogen receptor β, and others have given further advantages to discriminate between histological subgroups and could represent useful therapeutic targets. PMID:27195201

  10. Heterozygosity for a Bub1 mutation causes female-specific germ cell aneuploidy in mice

    SciTech Connect

    Leland, Shawn; Nagarajan, Prabakaran; Polyzos, Aris; Thomas, Sharon; Samaan, George; Donnell, Robert; Marchetti, Francesco; Venkatachalam, Sundaresan

    2009-06-24

    Aneuploidy, the most common chromosomal abnormality at birth and the main ascertained cause of pregnancy loss in humans, originates primarily from chromosome segregation errors during oogenesis. Here we report that heterozygosity for a mutation in the mitotic checkpoint kinase gene, Bub1, induces aneuploidy in female germ cells of mice, and that the effect increases with advancing maternal age. Analysis of Bub1 heterozygous oocytes showed that aneuploidy occurred primarily during the first meiotic division and involved premature sister chromatid separation. Furthermore, aneuploidy was inherited in zygotes and resulted in the loss of embryos after implantation. The incidence of aneuploidy in zygotes was sufficient to explain the reduced litter size in matings with Bub1 heterozygous females. No effects were seen in germ cells from heterozygous males. These findings show that Bub1 dysfunction is linked to inherited aneuploidy in female germ cells and may contribute to the maternal age-related increase in aneuploidy and pregnancy loss.

  11. Is the Blood-Brain Barrier Relevant in Metastatic Germ Cell Tumor?

    SciTech Connect

    Azar, Jose M. Schneider, Bryan P.; Einhorn, Lawrence H.

    2007-09-01

    Purpose: Germ cell tumors are uniquely chemosensitive and curable, even with advanced metastatic disease. Central nervous system recurrence can terminate a complete remission in other chemosensitive tumors, such as small cell lung cancer, because of the blood-brain barrier (BBB). We propose to document that the BBB is also relevant in germ cell tumors despite their dramatic chemosensitivity. Methods and Materials: We present five cases illustrating the concept of the BBB in patients with metastatic testicular cancer treated with chemotherapy. Results: In our large series of patients with metastatic testicular cancer treated with chemotherapy, we identified 5 unique patients. These patients were rendered free of disease only to experience relapse in the brain alone. This included 1 patient who initially had good-risk metastatic disease by means of the International Germ Cell Collaborative Group staging system at the onset of chemotherapy. Conclusions: The BBB is relevant in patients with metastatic testicular cancer.

  12. Primordial germ cell biology at the beginning of the XXI century.

    PubMed

    De Felici, Massimo

    2009-01-01

    At the XIV Workshop on the Development and Function of the Reproductive Organs held at the Congress Centre of the University of Rome Tor Vergata, Monteporzio Catone, Rome, Italy, the introduction to the first session entitled Mammalian primordial germ cells dedicated to the memory of Anne McLaren, was the occasion for a concise review of the state of art of research on the biology of primordial germ cells (PGCs). This great, unforgettable scientist, who died in a car accident in July 2007, dedicated most of her studies to this field over the last 25 years. Topics briefly reviewed in this Meeting Report are: 1) how the germ line is determined; 2) what are the mechanisms underlying PGC migration; 3) to what extent PGC survival, proliferation and differentiation are cell autonomous or environmentally controlled processes and 4) how the potential for totipotency is retained in PGCs.

  13. Germ cell formation from embryonic stem cells and the use of somatic cell nuclei in oocytes.

    PubMed

    Pelosi, Emanuele; Forabosco, Antonino; Schlessinger, David

    2011-03-01

    Embryonic stem cells (ESCs) have remarkable properties of pluripotency and self-renewal, along with the retention of chromosomal integrity. Germ cells function as a kind of "transgenerational stem cells," transmitting genetic information from one generation to the next. The formation of putative primordial germ cells (PGCs) and germ cells from mouse and human ESCs (hESCs) has, in fact, been shown, and the apparent derivation of functional mouse male gametes has also been described. Additionally, investigators have successfully reprogrammed somatic nuclei into a pluripotent state by inserting them into ESCs or oocytes. This would enable the generation of ESCs genetically identical to the somatic cell donor and their use in cell therapy. However, these methodologies are still inefficient and their mechanisms poorly understood. Until full comprehension of these processes is obtained, clinical applications remain remote. Nevertheless, they represent promising tools in the future, enhancing methods of therapeutic cloning and infertility treatment.

  14. Functional lacrimal gland regeneration by transplantation of a bioengineered organ germ.

    PubMed

    Hirayama, Masatoshi; Ogawa, Miho; Oshima, Masamitsu; Sekine, Yurie; Ishida, Kentaro; Yamashita, Kentaro; Ikeda, Kazutaka; Shimmura, Shigeto; Kawakita, Tetsuya; Tsubota, Kazuo; Tsuji, Takashi

    2013-01-01

    The lacrimal gland has a multifaceted role in maintaining a homeostatic microenvironment for a healthy ocular surface via tear secretion. Dry-eye disease, which is caused by lacrimal gland dysfunction, is one of the most prevalent eye diseases that cause corneal epithelial damage and results in significant loss of vision and a reduction in the quality of life. Here we demonstrate orthotopic transplantation of bioengineered lacrimal gland germs into adult mice with an extra-orbital lacrimal gland defect, a mouse model that mimics the corneal epithelial damage caused by lacrimal gland dysfunction. The bioengineered lacrimal gland germs and harderian gland germs both develop in vivo and achieve sufficient physiological functionality, including tear production in response to nervous stimulation and ocular surface protection. This study demonstrates the potential for bioengineered organ replacement to functionally restore the lacrimal gland. PMID:24084941

  15. [Multidrug-resistant germs in neurological early rehabilitation (2004-2013)].

    PubMed

    Rollnik, J D; Samady, A-M; Grüter, L

    2014-10-01

    Multidrug-resistant germs are an increasing problem in neurological and neurosurgical early rehabilitation but reliable data is missing. The present study examined the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and multidrug-resistant gram negative germs (MRGN) in a German neurological early rehabilitation facility (BDH Clinic Hessisch Oldendorf). Observation period was 2004-2013 (10 years). MRSA prevalence on admission was 11.4%, MRGN prevalence during rehabilitation 11.8%. A combination of different multidrug-resistant germs (MRSA plus MRGN) was observed in 3.8% of all cases. VRE were first detected in 2009, prevalence was as low as 0.1%. High prevalence of MRSA and MRGN raises major financial, medical, and ethical problems in early rehabilitation facilities. The authors encourage further multi-center studies and suggest a better recompense for this group of patients in the German DRG-system (Diagnosis Related Groups).

  16. Sufficient Numbers of Early Germ Cells Are Essential for Female Sex Development in Zebrafish

    PubMed Central

    Dai, Xiangyan; Jin, Xia; Chen, Xiaowen; He, Jiangyan; Yin, Zhan

    2015-01-01

    The sex determination for zebrafish is controlled by a combination of genetic and environmental factors. The determination of sex in zebrafish has been suggested to rely on a mechanism that is affected by germ cell-derived signals. To begin our current study, a simplified and efficient germ cell-specific promoter of the dead end (dnd) gene was identified. Utilizing the metrodinazole (MTZ)/ bacterial nitroreductase (NTR) system for inducible germ cell ablation, several stable Tg (dnd:NTR-EGFP-3'UTR) and Tg (dnd:NTR-EGFP+3'UTR) zebrafish lines were then generated with the identified promoter. A thorough comparison of the expression patterns and tissue distributions of endogenous dnd and ntr-egfp transcripts in vivo revealed that the identified 2032-bp zebrafish dnd promoter can recapitulate dnd expression faithfully in stable transgenic zebrafish. The correlation between the levels of the germ cell-derived signals and requirement for maintaining the female fate has been also explored with different durations of the MTZ treatments. Our results revealed the decreasing ratios of female presented in the treated transgenic group are fairly associated with the reducing levels of the early germ cell-derived signals. After the juvenile transgenic fish treated with 5 mM MTZ for 20 days, all MTZ-treated transgenic fish exclusively developed into males with subfertilities. Taken together, our results identified here a simplified and efficient dnd promoter, and provide clear evidence indicating that it was not the presence but the sufficiency of signals derived from germ cells that is essential for female sex development in zebrafish. Our model also provides a unique system for sex control in zebrafish studies. PMID:25679390

  17. Reproductive stage-dependent effects of additional cryoprotectant agents for the cryopreservation of stallion germ cells.

    PubMed

    Jung, Heejun; Kim, Namyoung; Yoon, Minjung

    2016-10-01

    The main objective of this study was to evaluate the efficacy of an additional cryoprotectant in 10% dimethyl sulfoxide (DMSO) on cryopreserving germ cells from stallions at different reproductive stages. Testicular samples were obtained from pre-pubertal (1-1.5 yr, n=6) and post-pubertal (3-7 yr, n=5) stallions. Germ cells were isolated using a two-enzyme digestion procedure and cryopreserved in minimal essential medium alpha containing 10% fetal bovine serum and 10% DMSO with or without addition of trehalose (50, 100, or 200mM) or polyethylene glycol (PEG, 2.5, 5, or 10%). Viability, cell population, and viable population were assessed after 1 and 3 months of cryopreservation. The viable UTF1-positive population of pre-pubertal stallion germ cells was also measured using immunocytochemistry after 1 and 3 months of cryopreservation. As expected, the viability, cell population, and viable cell population were significantly reduced after 1 and 3 months of cryopreservation. At the pre-pubertal stage, the addition of trehalose or PEG to 10% DMSO did not show any effect on the viability, cell population, viable cell population, or viable UTF1-positive germ cells at either 1 or 3 months after cryopreservation. However, at the post-pubertal stage, the viable population was significantly higher in germ cells that were cryopreserved with 5% or 10% PEG, than in the cells cryopreserved with 10% DMSO only. In conclusion, PEG at 5% or 10% added to 10% DMSO serves as an optimal cryoprotectant agent for the cryopreservation of germ cells from post-pubertal stallions. PMID:27546795

  18. Protective effect of quercetin on cadmium-induced oxidative toxicity on germ cells in male mice.

    PubMed

    Bu, Tongliang; Mi, Yuling; Zeng, Weidong; Zhang, Caiqiao

    2011-03-01

    Cadmium is a toxic heavy metal that is widely distributed in the environment. As a critical process, oxidative toxicity mediates the morphological and functional damages in germ cells after cadmium exposure. In this study, the protective effect of quercetin on cadmium-induced oxidative toxicity was investigated in mouse testicular germ cells. After oral administration of cadmium chloride at 4 mg/kg body weight for 2 weeks, damages in spermatozoa occurred in the early stage of spermatogenesis. Cadmium treatment significantly decreased the testicular antioxidant system, including decreases in the glutathione (GSH) level, superoxide dismutase (SOD), and GSH peroxidase (GSH-Px) activities. Moreover, exposure to cadmium resulted in an increase of hydrogen peroxide production and lipid peroxidation in testes. In addition, cadmium provoked germ cell apoptosis by upregulating expression of the proapoptotic proteins Bax and caspase-3 and downregulating expression of the antiapoptotic protein Bcl-XL. However, combined administration of a common flavonoid quercetin at 75 mg/kg body weight significantly attenuated cadmium-induced germ cell apoptosis by suppressing the hydrogen peroxide production and lipid peroxidation in testicular tissue. Simultaneous supplementation of quercetin markedly restored the decrease in GSH level and SOD and GSH-Px activities elicited by cadmium treatment. Additionally, quercetin protected germ cells from cadmium-induced apoptosis by downregulating the expression of Bax and caspase-3 and upregulating Bcl-XL expression. These results indicate that quercetin, due to its antioxidative and antiapoptotic characters, may manifest effective protective action against cadmium-induced oxidative toxicity in mouse testicular germ cells. PMID:21337715

  19. Melatonin alleviates cadmium-induced cellular stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Hua; Meng, Can; Zhao, Xian-Feng; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-01-01

    Increasing evidence demonstrates that melatonin has an anti-apoptotic effect in somatic cells. However, whether melatonin can protect against germ cell apoptosis remains obscure. Cadmium (Cd) is a testicular toxicant and induces germ cell apoptosis. In this study, we investigated the effects of melatonin on Cd-evoked germ cell apoptosis in testes. Male ICR mice were intraperitoneally (i.p.) injected with melatonin (5 mg/kg) every 8 hr, beginning at 8 hr before CdCl(2) (2.0 mg/kg, i.p.). As expected, acute Cd exposure resulted in germ cell apoptosis in testes, as determined by terminal dUTP nick-end labeling (TUNEL) staining. Melatonin significantly alleviated Cd-induced testicular germ cell apoptosis. An additional experiment showed that spliced form of XBP-1, the target of the IRE-1 pathway, was significantly increased in testes of mice injected with CdCl(2). GRP78, an endoplasmic reticulum (ER) chaperone, and CHOP, a downstream target of the PERK pathway, were upregulated in testes of Cd-treated mice. In addition, acute Cd exposure significantly increased testicular eIF2α and JNK phosphorylation, indicating that the unfolded protein response (UPR) pathway was activated by CdCl(2). Interestingly, melatonin almost completely inhibited Cd-induced ER stress and the UPR in testes. In addition, melatonin obviously attenuated Cd-induced heme oxygenase (HO)-1 expression and protein nitration in testes. Taken together, these results suggest that melatonin alleviates Cd-induced cellular stress and germ cell apoptosis in testes. Melatonin may be useful as pharmacological agents to protect against Cd-induced testicular toxicity. PMID:21793897

  20. Expression of steroidogenesis-related genes in murine male germ cells.

    PubMed

    Culty, Martine; Liu, Ying; Manku, Gurpreet; Chan, Wai-Yee; Papadopoulos, Vassilios

    2015-11-01

    For decades, only few tissues and cell types were defined as steroidogenic, capable of de novo steroid synthesis from cholesterol. However, with the refinement of detection methods, several tissues have now been added to the list of steroidogenic tissues. Besides their critical role as long-range acting hormones, steroids are also playing more discreet roles as local mediators and signaling molecules within the tissues they are produced. In testis, steroidogenesis is carried out by the Leydig cells through a broad network of proteins, mediating cholesterol delivery to CYP11A1, the first cytochrome of the steroidogenic cascade, and the sequential action of enzymes insuring the production of active steroids, the main one being testosterone. The knowledge that male germ cells can be directly regulated by steroids and that they express several steroidogenesis-related proteins led us to hypothesize that germ cells could produce steroids, acting as autocrine, intracrine and juxtacrine modulators, as a way to insure synchronized progression within spermatogenic cycles, and preventing inappropriate cell behaviors between neighboring cells. Gene expression and protein analyses of mouse and rat germ cells from neonatal gonocytes to spermatozoa showed that most steroidogenesis-associated genes are expressed in germ cells, showing cell type-, spermatogenic cycle-, and age-specific expression profiles. Highly expressed genes included genes involved in steroidogenesis and other cell functions, such as Acbd1 and 3, Tspo and Vdac1-3, and genes involved in fatty acids metabolism or synthesis, including Hsb17b4 10 and 12, implying broader roles than steroid synthesis in germ cells. These results support the possibility of an additional level of regulation of spermatogenesis exerted between adjacent germ cells.

  1. Doubly Uniparental Inheritance of Mitochondria As a Model System for Studying Germ Line Formation

    PubMed Central

    Milani, Liliana; Ghiselli, Fabrizio; Maurizii, Maria Gabriella; Passamonti, Marco

    2011-01-01

    Background Doubly Uniparental Inheritance (DUI) of mitochondria occurs when both mothers and fathers are capable of transmitting mitochondria to their offspring, in contrast to the typical Strictly Maternal Inheritance (SMI). DUI was found in some bivalve molluscs, in which two mitochondrial genomes are inherited, one through eggs, the other through sperm. During male embryo development, spermatozoon mitochondria aggregate in proximity of the first cleavage furrow and end up in the primordial germ cells, while they are dispersed in female embryos. Methodology/Principal Findings We used MitoTracker, microtubule staining and transmission electron microscopy to examine the mechanisms of this unusual distribution of sperm mitochondria in the DUI species Ruditapes philippinarum. Our results suggest that in male embryos the midbody deriving from the mitotic spindle of the first division concurs in positioning the aggregate of sperm mitochondria. Furthermore, an immunocytochemical analysis showed that the germ line determinant Vasa segregates close to the first cleavage furrow. Conclusions/Significance In DUI male embryos, spermatozoon mitochondria aggregate in a stable area on the animal-vegetal axis: in organisms with spiral segmentation this zone is not involved in cleavage, so the aggregation is maintained. Moreover, sperm mitochondria reach the same embryonic area in which also germ plasm is transferred. In 2-blastomere embryos, the segregation of sperm mitochondria in the same region with Vasa suggests their contribution in male germ line formation. In DUI male embryos, M-type mitochondria must be recognized by egg factors to be actively transferred in the germ line, where they become dominant replacing the Balbiani body mitochondria. The typical features of germ line assembly point to a common biological mechanism shared by DUI and SMI organisms. Although the molecular dynamics of the segregation of sperm mitochondria in DUI species are unknown, they could be a

  2. Genome Analysis of Elysia chlorotica Egg DNA Provides No Evidence for Horizontal Gene Transfer into the Germ Line of This Kleptoplastic Mollusc

    PubMed Central

    Bhattacharya, Debashish; Pelletreau, Karen N.; Price, Dana C.; Sarver, Kara E.; Rumpho, Mary E.

    2013-01-01

    The sea slug Elysia chlorotica offers a unique opportunity to study the evolution of a novel function (photosynthesis) in a complex multicellular host. Elysia chlorotica harvests plastids (absent of nuclei) from its heterokont algal prey, Vaucheria litorea. The “stolen” plastids are maintained for several months in cells of the digestive tract and are essential for animal development. The basis of long-term maintenance of photosynthesis in this sea slug was thought to be explained by extensive horizontal gene transfer (HGT) from the nucleus of the alga to the animal nucleus, followed by expression of algal genes in the gut to provide essential plastid-destined proteins. Early studies of target genes and proteins supported the HGT hypothesis, but more recent genome-wide data provide conflicting results. Here, we generated significant genome data from the E. chlorotica germ line (egg DNA) and from V. litorea to test the HGT hypothesis. Our comprehensive analyses fail to provide evidence for alga-derived HGT into the germ line of the sea slug. Polymerase chain reaction analyses of genomic DNA and cDNA from different individual E. chlorotica suggest, however, that algal nuclear genes (or gene fragments) are present in the adult slug. We suggest that these nucleic acids may derive from and/or reside in extrachromosomal DNAs that are made available to the animal through contact with the alga. These data resolve a long-standing issue and suggest that HGT is not the primary reason underlying long-term maintenance of photosynthesis in E. chlorotica. Therefore, sea slug photosynthesis is sustained in as yet unexplained ways that do not appear to endanger the animal germ line through the introduction of dozens of foreign genes. PMID:23645554

  3. Non-viral transfection of goat germline stem cells by nucleofection results in production of transgenic sperm after germ cell transplantation.

    PubMed

    Zeng, W; Tang, L; Bondareva, A; Luo, J; Megee, S O; Modelski, M; Blash, S; Melican, D T; Destrempes, M M; Overton, S A; Gavin, W G; Ayres, S; Echelard, Y; Dobrinski, I

    2012-04-01

    Germline stem cells (GSCs) can be used for large animal transgenesis, in which GSCs that are genetically manipulated in vitro are transplanted into a recipient testis to generate donor-derived transgenic sperm. The objectives of this study were to explore a non-viral approach for transgene delivery into goat GSCs and to investigate the efficiency of nucleofection in producing transgenic sperm. Four recipient goats received fractionated irradiation at 8 weeks of age to deplete endogenous GSCs. Germ cell transplantations were performed 8-9 weeks post-irradiation. Donor cells were collected from testes of 9-week-old goats, enriched for GSCs by Staput velocity sedimentation, and transfected by nucleofection with a transgene construct harboring the human growth hormone gene under the control of the goat beta-casein promoter (GBC) and a chicken beta-globin insulator (CBGI) sequence upstream of the promoter. For each recipient, transfected cells from 10 nucleofection reactions were pooled, mixed with non-transfected cells to a total of 1.5 × 10(8) cells in 3 ml, and transplanted into one testis (n = 4 recipients) by ultrasound-guided cannulation of the rete testis. The second testis of each recipient was removed. Semen was collected, starting at 9 months after transplantation, for a period of over a year (a total of 62 ejaculates from four recipients). Nested genomic PCR for hGH and CBGI sequences demonstrated that 31.3% ± 12.6% of ejaculates were positive for both hGH and CBGI. This study provides proof-of-concept that non-viral transfection (nucleofection) of primary goat germ cells followed by germ cell transplantation results in transgene transmission to sperm in recipient goats.

  4. Proteasome regulation of the chromodomain protein MRG-1 controls the balance between proliferative fate and differentiation in the C. elegans germ line.

    PubMed

    Gupta, Pratyush; Leahul, Lindsay; Wang, Xin; Wang, Chris; Bakos, Brendan; Jasper, Katie; Hansen, Dave

    2015-01-15

    The level of stem cell proliferation must be tightly controlled for proper development and tissue homeostasis. Multiple levels of gene regulation are often employed to regulate stem cell proliferation to ensure that the amount of proliferation is aligned with the needs of the tissue. Here we focus on proteasome-mediated protein degradation as a means of regulating the activities of proteins involved in controlling the stem cell proliferative fate in the C. elegans germ line. We identify five potential E3 ubiquitin ligases, including the RFP-1 RING finger protein, as being involved in regulating proliferative fate. RFP-1 binds to MRG-1, a homologue of the mammalian chromodomain-containing protein MRG15 (MORF4L1), which has been implicated in promoting the proliferation of neural precursor cells. We find that C. elegans with reduced proteasome activity, or that lack RFP-1 expression, have increased levels of MRG-1 and a shift towards increased proliferation in sensitized genetic backgrounds. Likewise, reduction of MRG-1 partially suppresses stem cell overproliferation. MRG-1 levels are controlled independently of the spatially regulated GLP-1/Notch signalling pathway, which is the primary signal controlling the extent of stem cell proliferation in the C. elegans germ line. We propose a model in which MRG-1 levels are controlled, at least in part, by the proteasome, and that the levels of MRG-1 set a threshold upon which other spatially regulated factors act in order to control the balance between the proliferative fate and differentiation in the C. elegans germ line. PMID:25564623

  5. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

    SciTech Connect

    Kheradmand, Arash; Dezfoulian, Omid; Alirezaei, Masoud; Rasoulian, Bahram

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact

  6. Compliance of males with stage 1 testicular germ cell tumours on an active surveillance protocol.

    PubMed

    Honeyball, F; Murali-Ganesh, R; Hruby, G; Grimison, P

    2015-10-01

    The aim of this retrospective study was to determine the rate of compliance among 57 males with stage 1 testicular germ cell tumours on an active surveillance protocol at a single Australian centre. At median follow up of 24 months, 81% had adequate compliance with the follow-up regimen, 12% were lost to follow up, and 16% relapsed; none between protocol visits. Active surveillance is an acceptable alternative to adjuvant therapy for stage 1 testicular germ cell tumours, with reduced toxicity for most and equivalent survival, but requires efforts to maintain adequate compliance with follow up to avoid late detection of recurrence.

  7. Modification of aqueous enzymatic oil extraction to increase the yield of corn oil from dry fractionated corn germ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In previous aqueous enzymatic extraction experiments we reported an oil yield of 67 grams from 800 grams of dry fractionated corn germ. In the current experiments, a dispersion of 10% cooked, dry-fractionated germ in water and was treated with amylases and a cellulase complex. A foam fraction was s...

  8. GermlncRNA: a unique catalogue of long non-coding RNAs and associated regulations in male germ cell development.

    PubMed

    Luk, Alfred Chun-Shui; Gao, Huayan; Xiao, Sizhe; Liao, Jinyue; Wang, Daxi; Tu, Jiajie; Rennert, Owen M; Chan, Wai-Yee; Lee, Tin-Lap

    2015-01-01

    Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/ PMID:25982314

  9. GermlncRNA: a unique catalogue of long non-coding RNAs and associated regulations in male germ cell development

    PubMed Central

    Luk, Alfred Chun-Shui; Gao, Huayan; Xiao, Sizhe; Liao, Jinyue; Wang, Daxi; Tu, Jiajie; Rennert, Owen M.; Chan, Wai-Yee; Lee, Tin-Lap

    2015-01-01

    Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/ PMID:25982314

  10. Effects of wheat germ agglutinin on human gastrointestinal epithelium: Insights from an experimental model of immune/epithelial cell interaction

    SciTech Connect

    Pellegrina, Chiara Dalla; Perbellini, Omar; Scupoli, Maria Teresa; Tomelleri, Carlo; Zanetti, Chiara; Zoccatelli, Gianni; Fusi, Marina; Peruffo, Angelo; Rizzi, Corrado; Chignola, Roberto

    2009-06-01

    Wheat germ agglutinin (WGA) is a plant protein that binds specifically to sugars expressed, among many others, by human gastrointestinal epithelial and immune cells. WGA is a toxic compound and an anti-nutritional factor, but recent works have shown that it may have potential as an anti-tumor drug and as a carrier for oral drugs. To quantitate the toxicity threshold for WGA on normal epithelial cells we previously investigated the effects of the lectin on differentiated Caco2 cells, and showed that in the micromolar range of concentrations WGA could alter the integrity of the epithelium layer and increase its permeability to both mannitol and dextran. WGA was shown to be uptaken by Caco2 cells and only {approx} 0.1% molecules were observed to cross the epithelium layer by transcytosis. Here we show that at nanomolar concentrations WGA is unexpectedly bioactive on immune cells. The supernatants of WGA-stimulated peripheral blood mononuclear cells (PBMC) can alter the integrity of the epithelium layer when administered to the basolateral side of differentiated Caco2 cells and the effects can be partially inhibited by monoclonal antibodies against IL1, IL6 and IL8. At nanomolar concentrations WGA stimulates the synthesis of pro-inflammatory cytokines and thus the biological activity of WGA should be reconsidered by taking into account the effects of WGA on the immune system at the gastrointestinal interface. These results shed new light onto the molecular mechanisms underlying the onset of gastrointestinal disorders observed in vivo upon dietary intake of wheat-based foods.

  11. Histological analysis of spermatogenesis and the germ cell development strategy within the testis of the male Western Cottonmouth Snake, Agkistrodon piscivorus leucostoma.

    PubMed

    Gribbins, Kevin M; Rheubert, Justin L; Collier, Matthew H; Siegel, Dustin S; Sever, David M

    2008-11-20

    Cottonmouth (Agkistrodon piscivorus leucostoma) testes were examined histologically to determine the germ cell development strategy employed during spermatogenesis. Testicular tissues from Cottonmouths were collected monthly from swamps around Hammond, Louisiana. Pieces of testis were fixed in Trump's fixative, dehydrated in ethanol, embedded in Spurr's plastic, sectioned with an ultramicrotome, and stained with toluidine blue and basic fuchsin. Spermatogenesis within Cottonmouths occurs in two independent events within a single calendar year. The testes are active during the months of March-June and August-October with spermiation most heavily observed during April-May and October. To our knowledge, this is the first study that describes bimodal spermatogenesis occurring in the same year within the subfamily Crotalinae. During spermatogenesis, no consistent spatial relationships are observed between germ cell generations. Typically, either certain cell types were missing (spermatocytes) or the layering of 3-5 spermatids and/or spermatocytes within the same cross-section of seminiferous tubule prevented consistent spatial stages from occurring. This temporal pattern of sperm development is different from the spatial development found within birds and mammals, being more reminiscent of that seen in amphibians, and has now been documented within every major clade of reptile (Chelonia, Serpentes, Sauria, Crocodylia). This primitive-like sperm development, within a testis structurally similar to mammals and birds, may represent an intermediate testicular model within the basally positioned (phylogenetically) reptiles that may be evolutionarily significant.

  12. Analysis of alkylresorcinols in wheat germ oil and barley germ oil via HPLC and flourescence detection: Cochromatography with tocols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alkylresorcinols are long chain phenolic compounds that have been reported to be localized in the outer layers of the kernels of wheat, rye, barley and other grains. A sensitive HPLC method with fluorescence detection was recently reported for the quantitative analysis of alkylresorcinols in cereal...

  13. Boundary Layer

    NASA Technical Reports Server (NTRS)

    Loitsianskii. L. G.

    1956-01-01

    The fundamental, practically the most important branch of the modern mechanics of a viscous fluid or a gas, is that branch which concerns itself with the study of the boundary layer. The presence of a boundary layer accounts for the origin of the resistance and lift force, the breakdown of the smooth flow about bodies, and other phenomena that are associated with the motion of a body in a real fluid. The concept of boundary layer was clearly formulated by the founder of aerodynamics, N. E. Joukowsky, in his well-known work "On the Form of Ships" published as early as 1890. In his book "Theoretical Foundations of Air Navigation," Joukowsky gave an account of the most important properties of the boundary layer and pointed out the part played by it in the production of the resistance of bodies to motion. The fundamental differential equations of the motion of a fluid in a laminar boundary layer were given by Prandtl in 1904; the first solutions of these equations date from 1907 to 1910. As regards the turbulent boundary layer, there does not exist even to this day any rigorous formulation of this problem because there is no closed system of equations for the turbulent motion of a fluid. Soviet scientists have done much toward developing a general theory of the boundary layer, and in that branch of the theory which is of greatest practical importance at the present time, namely the study of the boundary layer at large velocities of the body in a compressed gas, the efforts of the scientists of our country have borne fruit in the creation of a new theory which leaves far behind all that has been done previously in this direction. We shall herein enumerate the most important results by Soviet scientists in the development of the theory of the boundary layer.

  14. Syphilis - primary

    MedlinePlus

    Primary syphilis; Secondary syphilis; Late syphilis; Tertiary syphilis ... Syphilis is a sexually transmitted, infectious disease caused by the spirochete bacterium Treponema pallidum . This bacterium causes ...

  15. Chick limbs with mouse teeth: an effective in vivo culture system for tooth germ development and analysis.

    PubMed

    Koyama, Eiki; Wu, Changshan; Shimo, Tsuyoshi; Pacifici, Maurizio

    2003-01-01

    Mouse tooth germ development is currently studied by three main approaches: in wild-type and mutant mouse lines, after transplantation of tooth germs to ectopic sites, and in organ culture. The in vivo approaches are the most physiological but do not provide accessibility to tooth germs for further experimental manipulation. Organ cultures, although readily accessible, do not sustain full tooth germ development and are appropriate for short-term analysis. Thus, we sought to establish a new approach that would combine experimental accessibility with sustained development. We implanted fragments of embryonic day 12 mouse embryo first branchial arch containing early bud stage tooth germs into the lateral mesenchyme of day 4-5 chick embryo wing buds in ovo. Eggs were reincubated, and implanted tissues were examined by histochemistry and in situ hybridization over time. The tooth germs underwent seemingly normal growth, differentiation, and morphogenesis. They reached the cap, bell, and crown stages in approximately 3, 6, and 10 days, respectively, mimicking in a striking manner native temporal patterns. To examine mechanisms regulating tooth germ development, we first implanted tooth germ fragments, microinjected them with neutralizing antibodies to the key signaling molecule Sonic hedgehog (Shh), and examined them over time. Tooth germ development was markedly delayed, as revealed by poor morphogenesis and lack of mature ameloblasts and odontoblasts displaying characteristic traits such as an elongated cell shape, nuclear relocalization, and amelogenin gene expression. These phenotypic changes began to be reversed upon further incubation. The data show that the limb bud represents an effective, experimentally accessible as well as economical system for growth and analysis of developing tooth germs. The inhibitory effects of Shh neutralizing antibody treatment are discussed in relation to roles of this signaling pathway proposed by this and other groups previously.

  16. MEETING REPORT ASSESSING HUMAN GERM-CELL MUTAGENESIS IN THE POST-GENOME ERA: A CELEBRATION OF THE LEGACY OF WILLIAM LAWSON (BILL) RUSSELL

    EPA Science Inventory

    Although numerous germ-cell mutagens have been identified in animal model systems, to date, no human germ-cell mutagens have been confirmed. Because the genomic integrity of our germ cells is essential for the continuation of the human species, a resolution of this enduring conu...

  17. Male germ cells and photoreceptors, both dependent on close cell-cell interactions, degenerate upon ClC-2 Cl(-) channel disruption.

    PubMed

    Bösl, M R; Stein, V; Hübner, C; Zdebik, A A; Jordt, S E; Mukhopadhyay, A K; Davidoff, M S; Holstein, A F; Jentsch, T J

    2001-03-15

    The functions of some CLC Cl(-) channels are evident from human diseases that result from their mutations, but the role of the broadly expressed ClC-2 Cl(-) channel is less clear. Several important functions have been attributed to ClC-2, but contrary to these expectations ClC-2-deficient mice lacked overt abnormalities except for a severe degeneration of the retina and the testes, which led to selective male infertility. Seminiferous tubules did not develop lumina and germ cells failed to complete meiosis. Beginning around puberty there was a massive death of primary spermatocytes and later also of spermatogonia. Tubules were filled with abnormal Sertoli cells, which normally express ClC-2 in patches adjacent to germ cells. In the retina, photoreceptors lacked normal outer segments and degenerated between days P10 and P30. The current across the retinal pigment epithelium was severely reduced at P36. Thus, ClC-2 disruption entails the death of two cell types which depend on supporting cells that form the blood-testes and blood-retina barriers. We propose that ClC-2 is crucial for controlling the ionic environment of these cells. PMID:11250895

  18. Spallanzani Layers

    NASA Technical Reports Server (NTRS)

    2006-01-01

    31 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a layered, light-toned mesa among other layered materials exposed in a mound that covers much of the floor of Spallanzani Crater.

    Location near: 58.3oS, 273.9oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  19. DNA Methylation Errors in Cloned Mouse Sperm by Germ Line Barrier Evasion.

    PubMed

    Koike, Tasuku; Wakai, Takuya; Jincho, Yuko; Sakashita, Akihiko; Kobayashi, Hisato; Mizutani, Eiji; Wakayama, Sayaka; Miura, Fumihito; Ito, Takashi; Kono, Tomohiro

    2016-06-01

    The germ line reprogramming barrier resets parental epigenetic modifications according to sex, conferring totipotency to mammalian embryos upon fertilization. However, it is not known whether epigenetic errors are committed during germ line reprogramming that are then transmitted to germ cells, and consequently to offspring. We addressed this question in the present study by performing a genome-wide DNA methylation analysis using a target postbisulfite sequencing method in order to identify DNA methylation errors in cloned mouse sperm. The sperm genomes of two somatic cell-cloned mice (CL1 and CL7) contained significantly higher numbers of differentially methylated CpG sites (P = 0.0045 and P = 0.0116). As a result, they had higher numbers of differentially methylated CpG islands. However, there was no evidence that these sites were transmitted to the sperm genome of offspring. These results suggest that DNA methylation errors resulting from embryo cloning are transmitted to the sperm genome by evading the germ line reprogramming barrier. PMID:27103445

  20. The incidence and histological characteristics of intratubular germ cell neoplasia in postpubertal cryptorchid testis

    PubMed Central

    Ryang, Seung Hoon; Jung, Jae Hung; Eom, Minseob; Song, Jae Mann; Chung, Hyun Chul; Chae, Yunbyung; Lee, Chang Min

    2015-01-01

    Purpose It is well known that testicular germ cell tumors arise with increased frequency in patients with cryptorchidism. In addition, intratubular germ cell neoplasia (ITGCN) is a precursor lesion to testicular germ cell tumor. Approximately 50% of patients with ITGCN will develop an invasive of testicular germ cell tumors within 5 years. Therefore, we evaluated that the incidence of ITGCN in postpubertal cryptorchidism. Materials and Methods Between January 2002 and August 2012, orchiectomy specimens from 31 postpubertalpatients (aged 12 or over) with cryptorchid testis were reviewed. The specimens were evaluated for ITGCN using immunohistochemical stains of placental-like alkaline phosphatase and Oct 3/4 with routine hematoxylin-eosin stain. Additionally, the degree of spermatogenesis was assessed using the Johnsen score. Results Mean age was 34 years (range, 17 to 74 years) at surgery. All patients were diagnosed as unilateral cryptorchidism. One patient (3.2%) of 20-year-old had ITGCN in surgical specimen with all positive markers. Histological assessment of spermatogenesis showed that mean Johnsen score was 3.42 (range, 1 to 9). Majority of patients (27 of 31) presented impaired spermatogenesis with low Johnsen score lesser than 5. Conclusions Considering the risk of malignancy and low spermatogenesis, we should perform immunohistochemical stains and discuss preventative orchiectomy for the postpubertal cryptorchidism. PMID:26175870

  1. Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.

    PubMed

    Oulhen, Nathalie; Wessel, Gary M

    2016-10-01

    Nanos is a translational regulator required for the survival and maintenance of primordial germ cells. In the sea urchin, Strongylocentrotus purpuratus (Sp), Nanos 2 mRNA is broadly transcribed but accumulates specifically in the small micromere (sMic) lineage, in part because of the 3'UTR element GNARLE leads to turnover in somatic cells but retention in the sMics. Here we found that the Nanos 2 protein is also selectively stabilized; it is initially translated throughout the embryo but turned over in the future somatic cells and retained only in the sMics, the future germ line in this animal. This differential stability of Nanos protein is dependent on the open reading frame (ORF), and is independent of the sumoylation and ubiquitylation pathways. Manipulation of the ORF indicates that 68 amino acids in the N terminus of the Nanos protein are essential for its stability in the sMics whereas a 45 amino acid element adjacent to the zinc fingers targets its degradation. Further, this regulation of Nanos protein is cell autonomous, following formation of the germ line. These results are paradigmatic for the unique presence of Nanos in the germ line by a combination of selective RNA retention, distinctive translational control mechanisms (Oulhen et al., 2013), and now also by defined Nanos protein stability.

  2. The Magea gene cluster regulates male germ cell apoptosis without affecting the fertility in mice.

    PubMed

    Hou, Siyuan; Xian, Li; Shi, Peiliang; Li, Chaojun; Lin, Zhaoyu; Gao, Xiang

    2016-01-01

    While apoptosis is essential for male germ cell development, improper activation of apoptosis in the testis can affect spermatogenesis and cause reproduction defects. Members of the MAGE-A (melanoma antigen family A) gene family are frequently clustered in mammalian genomes and are exclusively expressed in the testes of normal animals but abnormally activated in a wide variety of cancers. We investigated the potential roles of these genes in spermatogenesis by generating a mouse model with a 210-kb genomic deletion encompassing six members of the Magea gene cluster (Magea1, Magea2, Magea3, Magea5, Magea6 and Magea8). Male mice carrying the deletion displayed smaller testes from 2 months old with a marked increase in apoptotic germ cells in the first wave of spermatogenesis. Furthermore, we found that Magea genes prevented stress-induced spermatogenic apoptosis after N-ethyl-N-nitrosourea (ENU) treatment during the adult stage. Mechanistically, deletion of the Magea gene cluster resulted in a dramatic increase in apoptotic germ cells, predominantly spermatocytes, with activation of p53 and induction of Bax in the testes. These observations demonstrate that the Magea genes are crucial in maintaining normal testicular size and protecting germ cells from excessive apoptosis under genotoxic stress. PMID:27226137

  3. Effects of actinomycin D on developing hamster molar tooth germs in vitro.

    PubMed

    Lyaruu, D M; van Duin, M A; Bervoets, T J; Wöltgens, J H; Bronckers, A L

    1997-02-01

    The aim of this study was to evaluate the toxic effects of actinomycin D on the developing hamster tooth germ in organ culture. Hamster tooth germs during early secretory amelogenesis were exposed in vitro for 24 h to 10(-9) M-5 x 10(-5) M actinomycin D. Actinomycin D dose-dependently (> or = 10(-7) M) decreased the tooth germ dry weight but mineralization was affected only by doses > or = 10(-5) M. However, the uptakes of TCA-insoluble 32P and [3H]thymidine were significantly reduced dose-dependently from > or = 10(-8) M actinomycin D, indicating that the drug inhibits the synthesis of phosphate-containing macromolecules as well as DNA synthesis. Histologically, 10(-8) M actinomycin D was the lowest dose which was not toxic to any cell type in the developing tooth germ. At 10(-7) M actinomycin D, the most sensitive cells were the proliferating pre-odontoblasts followed by pre-ameloblasts; the mature secretory ameloblasts and odontoblasts appeared unaffected. Higher doses resulted in increased cytotoxicity to the secretory cells and, eventually, total degeneration of most cells. The data suggest that children treated for cancer during tooth development using anti-chemotherapy cocktails containing actinomycin D (serum levels > 10(-7) M) may develop defects later on in the mature dentition as a direct consequence of the toxicity of the drug to the tooth organ.

  4. Angiotensin I Converting enzyme inhibitory peptides from commercial wet- and dry-milled corn germ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioprocesses were developed to enhance the value of proteins from de-oiled corn germ. Proteins were hydrolyzed with trypsin, GC106, Flavourzyme or thermolysin in order to free the bioactive peptide sequences. Protein hydrolysis, at an enzyme to substrate ratio of 1:250, was greater for wet- than d...

  5. Premeiotic germ cell defect in seminiferous tubules of Atm-null testis

    SciTech Connect

    Takubo, Keiyo . E-mail: keiyot@gmail.com; Hirao, Atsushi; Ohmura, Masako; Azuma, Masaki; Arai, Fumio; Nagamatsu, Go; Suda, Toshio . E-mail: sudato@sc.itc.keio.ac.jp

    2006-12-29

    Lifelong spermatogenesis is maintained by coordinated sequential processes including self-renewal of stem cells, proliferation of spermatogonial cells, meiotic division, and spermiogenesis. It has been shown that ataxia telangiectasia-mutated (ATM) is required for meiotic division of the seminiferous tubules. Here, we show that, in addition to its role in meiosis, ATM has a pivotal role in premeiotic germ cell maintenance. ATM is activated in premeiotic spermatogonial cells and the Atm-null testis shows progressive degeneration. In Atm-null testicular cells, differing from bone marrow cells of Atm-null mice, reactive oxygen species-mediated p16{sup Ink4a} activation does not occur in Atm-null premeiotic germ cells, which suggests the involvement of different signaling pathways from bone marrow defects. Although Atm-null bone marrow undergoes p16{sup Ink4a}-mediated cellular senescence program, Atm-null premeiotic germ cells exhibited cell cycle arrest and apoptotic elimination of premeiotic germ cells, which is different from p16{sup Ink4a}-mediated senescence.

  6. Boule Is Present in Fish and Bisexually Expressed in Adult and Embryonic Germ Cells of Medaka

    PubMed Central

    Xu, Hongyan; Li, Zhendong; Li, Mingyou; Wang, Li; Hong, Yunhan

    2009-01-01

    Background The DAZ family genes boule, daz and dazl encode RNA binding proteins essential for fertility of diverse animals including human. dazl has bisexual expression in both mitotic and meiotic germ cells, whereas daz has male premeiotic expression, and boule is largely a unisexual meiotic regulator. Although boule has been proposed as the ancestor for dazl/daz by gene duplication, it has been identified only in invertebrates and mammals. It has, however, remained unclear when and how the DAZ family has evolved in vertebrates. Methodology and Principal Findings This study was aimed at identifying and characterizing the DAZ family genes in fish as the basal vertebrate. We show that boule and dazl coexist in medaka and stickleback. Similar to the medaka dazl (Odazl), the medaka boule (Obol) is maternally supplied and segregates with primordial germ cells. Surprisingly, Obol is expressed in adult germ cells at pre-meiotic and meiotic stages of spermatogenesis and oogenesis. However, the maximal meiotic Obol expression in spermatocytes contrasts with the predominant pre-meiotic Odazl expression in spermatogonia, and the diffuse cytoplasmic Obol distribution in early oocytes contrasts with the Odazl concentration in the Balbinani's body. Conclusions The identification of fish boule and dazl genes provides direct evidence for the early gene duplication during vertebrate evolution. Our finding that Obol exhibits bisexual expression in both embryonic and adult germ cells considerably extends the diversity of boule expression patterns and offers a new insight into the evolutions of DAZ family members, expression patterns and functions in animal fertility. PMID:19564913

  7. Pathogenesis of PCV2a and PCV2b virus in germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic analysis of porcine circovirus type 2 (PCV2) reveals 2 subgroups that will be referred to as PCV2a and PCV2b representing the North American and European prototypes respectfully. This paper summarizes 3 studies comparing the pathogenesis of 2a and 2b viruses in germ-free pigs. In this PCV2...

  8. Effects of stress and aging on ribonucleoprotein assembly and function in the germ line.

    PubMed

    Schisa, Jennifer A

    2014-01-01

    In a variety of cell types, ribonucleoprotein (RNP) complexes play critical roles in regulating RNA metabolism. The germ line contains RNPs found also in somatic cells, such as processing (P) bodies and stress granules, as well as several RNPs unique to the germ line, including germ granules, nuage, Balbiani bodies, P granules, U bodies, and sponge bodies. Recent advances have identified a conserved response of germ line RNPs to environmental stresses such as nutritional stress and heat shock. The RNPs increase significantly in size based on cytology; their morphology and subcellular localization changes, and their composition changes. These dynamic changes are reversible when stresses diminish, and similar changes occur in response to aging or extended meiotic arrest prior to fertilization of oocytes. Intriguing correlations exist between the dynamics of the RNPs and the microtubule cytoskeleton and its motor proteins, suggesting a possible mechanism for the assembly and dissociation of the large RNP granules. Similarly, coordinated changes of the nuclear membrane and endoplasmic reticulum may also help unravel the regulatory mechanisms of RNP dynamics. Based on their composition, the RNPs are thought to regulate mRNA decay and/or translation, and initial support for some of these roles is now at hand. Ultimately, the question of why RNP remodeling occurs to such a large extent during a variety of stresses and aging remains to be fully answered, but a current attractive hypothesis is that the plasticity promotes the maintenance of oocyte quality. PMID:24523207

  9. DNA Methylation Errors in Cloned Mouse Sperm by Germ Line Barrier Evasion.

    PubMed

    Koike, Tasuku; Wakai, Takuya; Jincho, Yuko; Sakashita, Akihiko; Kobayashi, Hisato; Mizutani, Eiji; Wakayama, Sayaka; Miura, Fumihito; Ito, Takashi; Kono, Tomohiro

    2016-06-01

    The germ line reprogramming barrier resets parental epigenetic modifications according to sex, conferring totipotency to mammalian embryos upon fertilization. However, it is not known whether epigenetic errors are committed during germ line reprogramming that are then transmitted to germ cells, and consequently to offspring. We addressed this question in the present study by performing a genome-wide DNA methylation analysis using a target postbisulfite sequencing method in order to identify DNA methylation errors in cloned mouse sperm. The sperm genomes of two somatic cell-cloned mice (CL1 and CL7) contained significantly higher numbers of differentially methylated CpG sites (P = 0.0045 and P = 0.0116). As a result, they had higher numbers of differentially methylated CpG islands. However, there was no evidence that these sites were transmitted to the sperm genome of offspring. These results suggest that DNA methylation errors resulting from embryo cloning are transmitted to the sperm genome by evading the germ line reprogramming barrier.

  10. August Weismann's theory of the germ-plasm and the problem of unconceived alternatives.

    PubMed

    Stanford, P Kyle

    2005-01-01

    I have argued elsewhere that scientific realism is most significantly challenged neither by traditional arguments from underdetermination of theories by the evidence, nor by the traditional pessimistic induction, but by a rather different historical pattern: our repeated failure to conceive of alternatives to extant scientific theories, even when those alternatives were both (1) well-confirmed by the evidence available at the time and (2) sufficiently scientifically serious as to be later embraced by actual scientific communities. Here I use August Weismann's defense of his influential germ-plasm theory of inheritance to support my claim that this pattern characterizes the history of theoretical scientific investigation generally. Weismann believed that the germ-plasm must become disintegrated into its constituent elements over the course of development, I argue, only because he failed to conceive of any possible alternative mechanism of ontogenetic differentiation. This and other features of the germ-plasm theory, I suggest, reflect a still more fundamental failure to imagine that the germ-plasm might be a productive rather than expendable resource for the cell. Weismann's case provides impressive support for the problem of unconceived alternatives while rendering its challenge to scientific realism deeper and sharper in a number of important ways. PMID:16602485

  11. DEPS-1 promotes P-granule assembly and RNA interference in C. elegans germ cells

    PubMed Central

    Spike, Caroline A.; Bader, Jason; Reinke, Valerie; Strome, Susan

    2008-01-01

    P granules are germ-cell-specific cytoplasmic structures containing RNA and protein, and required for proper germ cell development in C. elegans. PGL-1 and GLH-1 were previously identified as critical components of P granules. We have identified a new P-granule-associated protein, DEPS-1, the loss of which disrupts P-granule structure and function. DEPS-1 is required for the proper localization of PGL-1 to P granules, the accumulation of glh-1 mRNA and protein, and germ cell proliferation and fertility at elevated temperatures. In addition, DEPS-1 is required for RNA interference (RNAi) of germline-expressed genes, possibly because DEPS-1 promotes the accumulation of RDE-4, a dsRNA-binding protein required for RNAi. A genome wide analysis of gene expression in deps-1 mutant germ lines identified additional targets of DEPS-1 regulation, many of which are also regulated by the RNAi factor RDE-3. Our studies suggest that DEPS-1 is a key component of the P-granule assembly pathway and that its roles include promoting accumulation of some mRNAs, such as glh-1 and rde-4, and reducing accumulation of other mRNAs, perhaps by collaborating with RDE-3 to generate endogenous short interfering RNAs (endo-siRNAs). PMID:18234720

  12. FGF, Insulin, and SMAD Signaling Cooperate for Avian Primordial Germ Cell Self-Renewal

    PubMed Central

    Whyte, Jemima; Glover, James D.; Woodcock, Mark; Brzeszczynska, Joanna; Taylor, Lorna; Sherman, Adrian; Kaiser, Pete; McGrew, Michael J.

    2015-01-01

    Summary Precise self-renewal of the germ cell lineage is fundamental to fertility and reproductive success. The early precursors for the germ lineage, primordial germ cells (PGCs), survive and proliferate in several embryonic locations during their migration to the embryonic gonad. By elucidating the active signaling pathways in migratory PGCs in vivo, we were able to create culture conditions that recapitulate this embryonic germ cell environment. In defined medium conditions without feeder cells, the growth factors FGF2, insulin, and Activin A, signaling through their cognate-signaling pathways, were sufficient for self-renewal of germline-competent PGCs. Forced expression of constitutively active MEK1, AKT, and SMAD3 proteins could replace their respective upstream growth factors. Unexpectedly, we found that BMP4 could replace Activin A in non-clonal growth conditions. These defined medium conditions identify the key molecular pathways required for PGC self-renewal and will facilitate efforts in biobanking of chicken genetic resources and genome editing. PMID:26677769

  13. The insulin sensitiser metformin regulates chicken Sertoli and germ cell populations.

    PubMed

    Faure, M; Guibert, E; Alves, S; Pain, B; Ramé, C; Dupont, J; Brillard, J P; Froment, P

    2016-05-01

    Metformin, an insulin sensitiser from the biguanide family of molecules, is used for the treatment of insulin resistance in type 2 diabetes individuals. It increases peripheral glucose uptake and may reduce food intake. Based on the tight link between metabolism and fertility, we investigated the role of metformin on testicular function using in vitro culture of Sertoli cells and seminiferous tubules, complemented by in vivo data obtained following metformin administration to prepubertal chickens. In vitro, metformin treatment reduced Sertoli cell proliferation without inducing apoptosis and morphological changes. The metabolism of Sertoli cells was affected because lactate secretion by Sertoli cells increased approximately twofold and intracellular free ATP was negatively impacted. Two important pathways regulating proliferation and metabolism in Sertoli cells were assayed. Metformin exposure was not associated with an increased phosphorylation of AKT or ERK. There was a 90% reduction in the proportion of proliferating germ cells after a 96-h exposure of seminiferous tubule cultures to metformin. In vivo, 6-week-old chickens treated with metformin for 3 weeks exhibited reduced testicular weight and a 50% decrease in testosterone levels. The expression of a marker of undifferentiated germ cells was unchanged in contrast to the decrease in expression of 'protamine', a marker of differentiated germ cells. In conclusion, these results suggest that metformin affects the testicular energy content and the proliferative ability of Sertoli and germ cells. PMID:26917452

  14. Human primordial germ cell commitment in vitro associates with a unique PRDM14 expression profile.

    PubMed

    Sugawa, Fumihiro; Araúzo-Bravo, Marcos J; Yoon, Juyong; Kim, Kee-Pyo; Aramaki, Shinya; Wu, Guangming; Stehling, Martin; Psathaki, Olympia E; Hübner, Karin; Schöler, Hans R

    2015-04-15

    Primordial germ cells (PGCs) develop only into sperm and oocytes in vivo. The molecular mechanisms underlying human PGC specification are poorly understood due to inaccessibility of cell materials and lack of in vitro models for tracking the earliest stages of germ cell development. Here, we describe a defined and stepwise differentiation system for inducing pre-migratory PGC-like cells (PGCLCs) from human pluripotent stem cells (PSCs). In response to cytokines, PSCs differentiate first into a heterogeneous mesoderm-like cell population and then into PGCLCs, which exhibit minimal PRDM14 expression. PGC specification in humans is similar to the murine process, with the sequential activation of mesodermal and PGC genes, and the suppression of neural induction and of de novo DNA methylation, suggesting that human PGC formation is induced via epigenesis, the process of germ cell specification via inductive signals from surrounding somatic cells. This study demonstrates that PGC commitment in humans shares key features with that of the mouse, but also highlights key differences, including transcriptional regulation during the early stage of human PGC development (3-6 weeks). A more comprehensive understanding of human germ cell development may lead to methodology for successfully generating PSC-derived gametes for reproductive medicine.

  15. A conserved chromatin architecture marks and maintains the restricted germ cell lineage in worms and flies.

    PubMed

    Schaner, Christine E; Deshpande, Girish; Schedl, Paul D; Kelly, William G

    2003-11-01

    In C. elegans, mRNA production is initially repressed in the embryonic germline by a protein unique to C. elegans germ cells, PIE-1. PIE-1 is degraded upon the birth of the germ cell precursors, Z2 and Z3. We have identified a chromatin-based mechanism that succeeds PIE-1 repression in these cells. A subset of nucleosomal histone modifications, methylated lysine 4 on histone H3 (H3meK4) and acetylated lysine 8 on histone H4 (H4acetylK8), are globally lost and the DNA appears more condensed. This coincides with PIE-1 degradation and requires that germline identity is not disrupted. Drosophila pole cell chromatin also lacks H3meK4, indicating that a unique chromatin architecture is a conserved feature of embryonic germ cells. Regulation of the germline-specific chromatin architecture requires functional nanos activity in both organisms. These results indicate that genome-wide repression via a nanos-regulated, germ cell-specific chromatin organization is a conserved feature of germline maintenance during embryogenesis.

  16. The development of a "Green" aqueous enzymatic process to extract corn oil from corn germ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 2.4 million tons of commercial corn oil were produced worldwide in 2012, compared to 2012 world production of palm oil (53.3 MT) and soybean oil (43.1 MT) according to FAS, USDA. Most commercial corn oil (~90%) is produced from corn germ that is expeller pressed and/or hexane extracte...

  17. Germ derived free amino nitrogen as supplement for corn endosperm fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn endosperm separated by dry fractionation could exhibit poor fermentation performance due to loss of germ components beneficial for yeast growth. Inorganic nitrogen and other nutritional supplementations are used to overcome sluggish fermentation. We investigated the use of a protease in gener...

  18. Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.

    PubMed

    Oulhen, Nathalie; Wessel, Gary M

    2016-10-01

    Nanos is a translational regulator required for the survival and maintenance of primordial germ cells. In the sea urchin, Strongylocentrotus purpuratus (Sp), Nanos 2 mRNA is broadly transcribed but accumulates specifically in the small micromere (sMic) lineage, in part because of the 3'UTR element GNARLE leads to turnover in somatic cells but retention in the sMics. Here we found that the Nanos 2 protein is also selectively stabilized; it is initially translated throughout the embryo but turned over in the future somatic cells and retained only in the sMics, the future germ line in this animal. This differential stability of Nanos protein is dependent on the open reading frame (ORF), and is independent of the sumoylation and ubiquitylation pathways. Manipulation of the ORF indicates that 68 amino acids in the N terminus of the Nanos protein are essential for its stability in the sMics whereas a 45 amino acid element adjacent to the zinc fingers targets its degradation. Further, this regulation of Nanos protein is cell autonomous, following formation of the germ line. These results are paradigmatic for the unique presence of Nanos in the germ line by a combination of selective RNA retention, distinctive translational control mechanisms (Oulhen et al., 2013), and now also by defined Nanos protein stability. PMID:27424271

  19. Positive mRNA Translational Control in Germ Cells by Initiation Factor Selectivity

    PubMed Central

    Friday, Andrew J.; Keiper, Brett D.

    2015-01-01

    Ultimately, the production of new proteins in undetermined cells pushes them to new fates. Other proteins hold a stem cell in a mode of self-renewal. In germ cells, these decision-making proteins are produced largely from translational control of preexisting mRNAs. To date, all of the regulation has been attributed to RNA binding proteins (RBPs) that repress mRNAs in many models of germ cell development (Drosophila, mouse, C. elegans, and Xenopus). In this review, we focus on the selective, positive function of translation initiation factors eIF4E and eIF4G, which recruit mRNAs to ribosomes upon derepression. Evidence now shows that the two events are not separate but rather are coordinated through composite complexes of repressors and germ cell isoforms of eIF4 factors. Strikingly, the initiation factor isoforms are themselves mRNA selective. The mRNP complexes of translation factors and RBPs are built on specific populations of mRNAs to prime them for subsequent translation initiation. Simple rearrangement of the partners causes a dormant mRNP to become synthetically active in germ cells when and where they are required to support gametogenesis. PMID:26357652

  20. Expression, sorting, and segregation of Golgi proteins during germ cell differentiation in the testis

    PubMed Central

    Au, Catherine E.; Hermo, Louis; Byrne, Elliot; Smirle, Jeffrey; Fazel, Ali; Simon, Paul H. G.; Kearney, Robert E.; Cameron, Pamela H.; Smith, Charles E.; Vali, Hojatollah; Fernandez-Rodriguez, Julia; Ma, Kewei; Nilsson, Tommy; Bergeron, John J. M.

    2015-01-01

    The molecular basis of changes in structure, cellular location, and function of the Golgi apparatus during male germ cell differentiation is unknown. To deduce cognate Golgi proteins, we isolated germ cell Golgi fractions, and 1318 proteins were characterized, with 20 localized in situ. The most abundant protein, GL54D of unknown function, is characterized as a germ cell–specific Golgi-localized type II integral membrane glycoprotein. TM9SF3, also of unknown function, was revealed to be a universal Golgi marker for both somatic and germ cells. During acrosome formation, several Golgi proteins (GBF1, GPP34, GRASP55) localize to both the acrosome and Golgi, while GL54D, TM9SF3, and the Golgi trafficking protein TMED7/p27 are segregated from the acrosome. After acrosome formation, GL54D, TM9SF3, TMED4/p25, and TMED7/p27 continue to mark Golgi identity as it migrates away from the acrosome, while the others (GBF1, GPP34, GRASP55) remain in the acrosome and are progressively lost in later steps of differentiation. Cytoplasmic HSP70.2 and the endoplasmic reticulum luminal protein-folding enzyme PDILT are also Golgi recruited but only during acrosome formation. This resource identifies abundant Golgi proteins that are expressed differentially during mitosis, meiosis, and postacrosome Golgi migration, including the last step of differentiation. PMID:25808494

  1. Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

    PubMed Central

    Selle, F.; Gligorov, J.; Richard, S.; Khalil, A.; Alexandre, I.; Avenin, D.; Provent, S.; Soares, D.G.; Lotz, J.P.

    2014-01-01

    Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis. PMID:25493378

  2. Effects of stress and aging on ribonucleoprotein assembly and function in the germ line

    PubMed Central

    Schisa, Jennifer A.

    2016-01-01

    In a variety of cell types, ribonucleoprotein (RNP) complexes play critical roles in regulating RNA metabolism. The germ line contains RNPs found also in somatic cells, such as processing (P) bodies and stress granules, as well as several RNPs unique to the germ line, including germ granules, nuage, Balbiani bodies, P granules, U bodies, and sponge bodies. Recent advances have identified a conserved response of germ line RNPs to environmental stresses such as nutritional stress and heat shock. The RNPs increase significantly in size based on cytology; their morphology and subcellular localization changes, and their composition changes. These dynamic changes are reversible when stresses diminish, and similar changes occur in response to aging or extended meiotic arrest prior to fertilization of oocytes. Intriguing correlations exist between the dynamics of the RNPs and the microtubule cytoskeleton and its motor proteins, suggesting a possible mechanism for the assembly and dissociation of the large RNP granules. Similarly, coordinated changes of the nuclear membrane and endoplasmic reticulum may also help unravel the regulatory mechanisms of RNP dynamics. Based on their composition, the RNPs are thought to regulate mRNA decay and/or translation, and initial support for some of these roles is now at hand. Ultimately, the question of why RNP remodeling occurs to such a large extent during a variety of stresses and aging remains to be fully answered, but a current attractive hypothesis is that the plasticity promotes the maintenance of oocyte quality. PMID:24523207

  3. The emerging role of matrix metalloproteases of the ADAM family in male germ cell apoptosis

    PubMed Central

    Urriola-Muñoz, Paulina; Lagos-Cabré, Raúl

    2011-01-01

    Constitutive germ cell apoptosis during mammalian spermatogenesis is a key process for controlling sperm output and to eliminate damaged or unwanted cells. An increase or decrease in the apoptosis rate has deleterious consequences and leads to low sperm production. Apoptosis in spermatogenesis has been widely studied, but the mechanism by which it is induced under physiological or pathological conditions has not been clarified. We have recently identified the metalloprotease ADAM17 (TACE) as a putative physiological inducer of germ cell apoptosis. The mechanisms involved in regulating the shedding of the ADAM17 extracellular domain are still far from being understood, although they are important in order to understand cell-cell communications. Here, we review the available data regarding apoptosis during mammalian spermatogenesis and the localization of ADAM proteins in the male reproductive tract. We propose an integrative working model where ADAM17, p38 MAPK, protein kinase C (PKC) and the tyrosine kinase c-Abl participate in the physiological signalling cascade inducing apoptosis in germ cells. In our model, we also propose a role for the Sertoli cell in regulating the Fas/FasL system in order to induce the extrinsic pathway of apoptosis in germ cells. This working model could be applied to further understand constitutive apoptosis in spermatogenesis and in pathological conditions (e.g., varicocele) or following environmental toxicants exposure (e.g., genotoxicity or xenoestrogens). PMID:22319668

  4. Germ-cell nondisjunction in testes biopsies of men with idiopathic infertility.

    PubMed Central

    Huang, W J; Lamb, D J; Kim, E D; de Lara, J; Lin, W W; Lipshultz, L I; Bischoff, F Z

    1999-01-01

    Intracytoplasmic sperm injection (ICSI) has been used in combination with testicular sperm extraction to achieve pregnancies in couples with severe male-factor infertility, yet many of the underlying genetic mechanisms remain largely unknown. To investigate nondisjunction in mitotic and meiotic germ cells, we performed three-color FISH to detect numeric chromosome aberrations in testicular tissue samples from infertile men confirmed to have impaired spermatogenesis of unknown cause. FISH was employed to determine the rate of sex-chromosome aneuploidy in germ cells. Nuclei were distinguished as haploid or diploid, respectively. The overall incidence of sex-chromosome aneuploidy in germ cells was found to be significantly higher (P<.00001) in all three abnormal histopathologic patterns (range 39.0%-43.5%) as compared with normal controls (29.1%). The relative ratio of normal to aneuploid nuclei in the diploid cells of patients with impaired spermatogenesis was approximately 1.0, a >300% decrease when compared with the 4.42 ratio detected in patients with normal spermatogenesis. These results provide direct evidence of an increased incidence of sex-chromosome aneuploidy observed in germ cells of men with severely impaired spermatogenesis who might be candidates for ICSI with sperm obtained directly from the testis. The incidence of aneuploidy was significantly greater among the diploid nuclei, which suggests that chromosome instability is a result of altered genetic control during mitotic cell division and proliferation during spermatogenesis. PMID:10330350

  5. DAZL limits pluripotency, differentiation, and apoptosis in developing primordial germ cells.

    PubMed

    Chen, Hsu-Hsin; Welling, Maaike; Bloch, Donald B; Muñoz, Javier; Mientjes, Edwin; Chen, Xinjie; Tramp, Cody; Wu, Jie; Yabuuchi, Akiko; Chou, Yu-Fen; Buecker, Christa; Krainer, Adrian; Willemsen, Rob; Heck, Albert J; Geijsen, Niels

    2014-11-11

    The scarcity of primordial germ cells (PGCs) in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell development. Using Dazl-GFP reporter ESCs, we demonstrate that DAZL plays a central role in a large mRNA/protein interactive network that blocks the translation of core pluripotency factors, including Sox2 and Sall4, as well as of Suz12, a polycomb family member required for differentiation of pluripotent cells. Thus, DAZL limits both pluripotency and somatic differentiation in nascent PGCs. In addition, we observed that DAZL associates with mRNAs of key Caspases and similarly inhibits their translation. This elegant fail-safe mechanism ensures that, whereas loss of DAZL results in prolonged expression of pluripotency factors, teratoma formation is avoided due to the concomitant activation of the apoptotic cascade. PMID:25418731

  6. The Magea gene cluster regulates male germ cell apoptosis without affecting the fertility in mice

    PubMed Central

    Hou, Siyuan; Xian, Li; Shi, Peiliang; Li, Chaojun; Lin, Zhaoyu; Gao, Xiang

    2016-01-01

    While apoptosis is essential for male germ cell development, improper activation of apoptosis in the testis can affect spermatogenesis and cause reproduction defects. Members of the MAGE-A (melanoma antigen family A) gene family are frequently clustered in mammalian genomes and are exclusively expressed in the testes of normal animals but abnormally activated in a wide variety of cancers. We investigated the potential roles of these genes in spermatogenesis by generating a mouse model with a 210-kb genomic deletion encompassing six members of the Magea gene cluster (Magea1, Magea2, Magea3, Magea5, Magea6 and Magea8). Male mice carrying the deletion displayed smaller testes from 2 months old with a marked increase in apoptotic germ cells in the first wave of spermatogenesis. Furthermore, we found that Magea genes prevented stress-induced spermatogenic apoptosis after N-ethyl-N-nitrosourea (ENU) treatment during the adult stage. Mechanistically, deletion of the Magea gene cluster resulted in a dramatic increase in apoptotic germ cells, predominantly spermatocytes, with activation of p53 and induction of Bax in the testes. These observations demonstrate that the Magea genes are crucial in maintaining normal testicular size and protecting germ cells from excessive apoptosis under genotoxic stress. PMID:27226137

  7. Utility of Dexrazoxane for the Attenuation of Epirubicin-Induced Genetic Alterations in Mouse Germ Cells

    PubMed Central

    Ahmad, Sheikh F.; Ansaria, Mushtaq A.; Nadeem, Ahmed; Al-Shabanah, Othman A.; Al-Harbi, Mohammed M.; Bakheet, Saleh A.

    2016-01-01

    Dexrazoxane has been approved to treat anthracycline-induced cardiomyopathy and extravasation. However, the effect of dexrazoxane on epirubicin-induced genetic alterations in germ cells has not yet been reported. Thus, the aim of this study was to determine whether dexrazoxane modulates epirubicin-induced genetic damage in the germ cells of male mice. Our results show that dexrazoxane was not genotoxic at the tested doses. Furthermore, it protected mouse germ cells against epirubicin-induced genetic alterations as detected by the reduction in disomic and diploid sperm, spermatogonial chromosomal aberrations, and abnormal sperm heads. The attenuating effect of dexrazoxane was greater at higher dose, indicating a dose-dependent effect. Moreover, sperm motility and count were ameliorated by dexrazoxane pretreatment. Epirubicin induced marked biochemical changes characteristic of oxidative DNA damage including elevated 8-hydroxy-2ʹ-deoxyguanosine levels and reduction in reduced glutathione. Pretreatment of mice with dexrazoxane before epirubicin challenge restored these altered endpoints. We conclude that dexrazoxane may efficiently mitigate the epirubicin insult in male germ cells, and prevent the enhanced risk of abnormal reproductive outcomes and associated health risks. Thus, pretreating patients with dexrazoxane prior to epirubicin may efficiently preserve not only sperm quality but also prevent the transmission of genetic damage to future generations. PMID:27690233

  8. Use of Mueller-Hinton broth and agar in the germ tube test.

    PubMed

    Mattei, Antonella Souza; Alves, Sydney Hartz; Severo, Cecília Bittencourt; Guazzelli, Luciana da Silva; Oliveira, Flávio de Mattos; Severo, Luiz Carlos

    2014-01-01

    Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT) test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis). The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH) broth and agar. GT was observed in 96% (130/136) of the isolates through the fresh serum technique, 94% (128/136) through previously frozen serum, 92% (125/136) in MH agar, and 90% (122/136) in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test.

  9. Maintaining a Sanitary Child Care Environment -- Six Tips for Germ Control.

    ERIC Educational Resources Information Center

    Aronson, Susan S.

    2001-01-01

    Recommends keeping body defenses strong, and keeping all surfaces clean and some surfaces sanitary. Urges using federally mandated precautions for blood spills, avoiding germ-trapping artificial or long fingernails and jewelry, practicing good hand washing, and organizing the environment to avoid contamination. Includes table relating child care…

  10. Ectopic Expression of Testis Germ Cell Proteins in Cancer and Its Potential Role in Genomic Instability.

    PubMed

    Nielsen, Aaraby Yoheswaran; Gjerstorff, Morten Frier

    2016-01-01

    Genomic instability is a hallmark of human cancer and an enabling factor for the genetic alterations that drive cancer development. The processes involved in genomic instability resemble those of meiosis, where genetic material is interchanged between homologous chromosomes. In most types of human cancer, epigenetic changes, including hypomethylation of gene promoters, lead to the ectopic expression of a large number of proteins normally restricted to the germ cells of the testis. Due to the similarities between meiosis and genomic instability, it has been proposed that activation of meiotic programs may drive genomic instability in cancer cells. Some germ cell proteins with ectopic expression in cancer cells indeed seem to promote genomic instability, while others reduce polyploidy and maintain mitotic fidelity. Furthermore, oncogenic germ cell proteins may indirectly contribute to genomic instability through induction of replication stress, similar to classic oncogenes. Thus, current evidence suggests that testis germ cell proteins are implicated in cancer development by regulating genomic instability during tumorigenesis, and these proteins therefore represent promising targets for novel therapeutic strategies.

  11. In vitro generation and characterization of chicken long-term germ cells from different embryonic origins.

    PubMed

    Raucci, Franca; Fuet, Aurelie; Pain, Bertrand

    2015-09-15

    Primordial germ cells (PGCs) are the precursors of differentiated germ cells. Located in the epiblast of a stage X (EG&K) embryo, the PGCs translocate anteriorly to the germinal crescent and migrate, within 48 to 56 hours of development, through the blood vascular system to the germinal ridges where they become the gonadal germ cells (GGCs). We aim to generate, compare, and determine the basic characters of the in vitro long-term cultured PGCs derived from (1) the chicken blastodermal cells (at stages IX-XII); (2) the chicken blood of a 2-day old embryo (stages 14-17 Hamburger Hamilton [HH]); and (3) the long-term cultured gonocytes taken from male gonads of a 5- to 6-day-old embryo (stages 29-30 HH). In presence of fibroblast growth factor, chicken blastodermal cells are able to long-term proliferate and generate small, round, alkaline phosphatase-positive cell clusters. Molecular characterization shows that these selected and amplified clusters show a PGC-like cell profile, as they express cPOUV (a pluripotent-associated marker), NR6A1/GCNF and DDX4/CVH (germ cell-specific genes). Both chicken PGCs and GGCs, obtained from embryonic blood and gonads, at 14 to 17 HH and 29 to 30 HH, respectively, generate long-term germ cell cultures and positively react in vitro to periodic acid-Schiff. Immunochemical analyses reveal that these cell lines are specifically recognized by anti-SSEA-1, anti-EMA-1, anti-CVH, anti-β1-integrin, and anti-CEACAM antibodies. The presence of surrounding cells may suggest a stronger dependency toward the niche process for the GGCs. The reactivity of chicken embryonic germ cells obtained from the two different sources to the specific markers used in this study was not altered through the culture. In conclusion, the morphologic analysis specific for chicken PGCs and GGCs will further contribute to quick and reliable characterization of long-term cultured in vitro chicken germ cells.

  12. Brain Metastases as Presenting Feature in 'Burned Out' Testicular Germ Cell Tumor

    PubMed Central

    Brunet, Bryan

    2016-01-01

    Testicular germ cell tumors (TGCTs) are the most common malignancy in males aged 20 to 39, and the incidence is increasing. TGCTs have a tendency to grow rapidly with a high risk of metastatic spread. TGCTs generally present with a palpable testicular mass, yet may present less commonly with symptoms arising from metastatic disease.  A 24-year-old otherwise healthy male presented with progressive headaches. Initial imaging reported a single mass in the right frontal lobe. Complete surgical resection revealed suspicion for metastatic poorly differentiated carcinoma with an inconclusive immunohistochemical profile. Further staging scans revealed pulmonary and pelvic tumor deposits. Tumor markers with alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase were not elevated. Follow-up cranial magnetic resonance imaging revealed intracranial disease progression and he underwent whole brain radiation therapy. Additional outside pathology consultation for chromosomal analysis revealed features consistent with a TGCT. A scrotal ultrasound revealed a minimally atrophic right testicle. With evidence supporting the potential for response to chemotherapeutic treatment in TGCT, the patient was started on cisplatin and etoposide. Bleomycin was planned for the second cycle of chemotherapy if his pulmonary function improved.  A salient feature of all invasive TGCTs is a gain in material in the short arm of chromosome 12, and is diagnostic if present. Although the initial pathology revealed a non-diagnostic metastatic tumor, further testing revealed amplification of chromosome 12p. The examination of poorly differentiated carcinomas of an unknown primary site using light microscopy and immunohistochemical profiling alone may be inadequate, and should undergo molecular chromosomal analysis. This case is presented for its unconventional presentation and rarity of occurrence. It brings forward the discussion of both the commonality of TGCT in young male

  13. Benzene-induced histopathological changes and germ cell population dynamics in testes of Sprague Dawley rats.

    PubMed

    Singh, R K; Bansode, F W

    2011-11-01

    Benzene has been considered as an occupational hematotoxin and leukemogen. The present study was conducted to determine the effects of oral administration of benzene on reproductive organs and testicular spermatogenesis in rats. Adult rats were divided into three weight matched groups (Gr. I-III) containing 6 each. Gr. I rats received vehicle only and served as control. Rats in Gr. II and III were fed orally with 0.5 and 1 ml kg(-1) dose of benzene for 14 and 9 days, respectively and autopsy was done on 15th and 10th day. Food and water intake and gross behavioral changes were recorded daily during the entire treatment. Results showed no significant change in reproductive organ weights viz. testis, epididymis and ventral prostate in benzene-treated (0.5 or 1 ml kg(-1)) rats than that in controls. But, caused a significant decrease (p < 0.005) in weights of seminal vesicles in rats treated with both 0.5 and 1 ml kg(-1) doses compared to control. In contrast, at higher dose (1 ml kg(-1)) of benzene, significant (p < 0.001) decline in body weight and 100% mortality was observed on day 10 of autopsy. In treated rats, testicular cytotoxicity was marked by multinucleated giant cells formation, cytoplasmic vacuolization, pyknosis of nuclei, chromatolysis, desquamation and dissolution of germ cells in tubular lumen. The quantitative analysis of spermatogenesis showed a significant (p < 0.001) decrease in number ofA-spermatogonia (in 1 ml kg(-1) dose only), primary spermatocytes (non-pachytene and pachytene) and spermatids (round and elongated) in treated as compared to control rats. The diameters of testicular tubules and Leydig cells nuclei were also significantly (p < 0.001) reduced in treated rats. A steady loss in food and water intake recorded and signs of ill health were observed in treated (0.5 or 1 ml kg(-1)) rats. Results of the study indicated antitesticular lantispermatogenic effects of benzene at 0.5 and 1 ml kg(-1) dose in rats.

  14. Propagation of human germ stem cells in long-term culture

    PubMed Central

    Akhondi, Mohammad Mehdi; Mohazzab, Arash; Jeddi-Tehrani, Mahmood; Sadeghi, Mohammad Reza; Eidi, Akram; Khodadadi, Abbas; Piravar, Zeinab

    2013-01-01

    Background: Spermatogonial stem cells (SSCs), a subset of undifferentiated type A spermatogonia, are the foundation of complex process of spermatogenesis and could be propagated in vitro culture conditions for long time for germ cell transplantation and fertility preservation. Objective: The aim of this study was in vitro propagation of human spermatogonial stem cells (SSCs) and improvement of presence of human Germ Stem Cells (hGSCs) were assessed by specific markers POU domain, class 5, transcription factor 1 (POU5F1), also known as Octamer-binding transcription factor 4 (Oct-4) and PLZF (Promyelocytic leukaemia zinc finger protein). Materials and Methods: Human testicular cells were isolated by enzymatic digestion (Collagenase IV and Trypsin). Germ cells were cultured in Stem-Pro 34 media supplemented by growth factors such as glial cell line-derived neurotrophic factor, basic fibroblast growth factor, epidermal growth factor and leukemia inhibitory factor to support self-renewal divisions. Germline stem cell clusters were passaged and expanded every week. Immunofluorecent study was accomplished by Anti-Oct4 antibody through the culture. The spermatogonial stem cells genes expression, PLZF, was studied in testis tissue and germ stem cells entire the culture. Results: hGSCs clusters from a brain dead patient developed in testicular cell culture and then cultured and propagated up to 6 weeks. During the culture Oct4 were a specific marker for identification of hGSCs in testis tissue. Expression of PLZF was applied on RNA level in germ stem cells. Conclusion: hGSCs indicated by SSCs specific marker can be cultured and propagated for long-term in vitro conditions. This article extracted from Ph.D. Thesis. (Zeinab Piravar) PMID:24639790

  15. Sensitivity of spore germination and germ tube elongation of Saccharina japonica to metal exposure.

    PubMed

    Han, Taejun; Kong, Jeong-Ae; Kang, Hee-Gyu; Kim, Seon-Jin; Jin, Gyo-Sun; Choi, Hoon; Brown, Murray T

    2011-11-01

    The sensitivity of early life stages of the brown seaweed Saccharina japonica to six metals (Cd, Cu, Hg, Ni, Pb, Zn) and two waste-water samples were investigated and a new toxicity bioassay developed. The two endpoints used were spore germination and germ tube elongation with an exposure time of 24 h. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were darkness, pH 8, 35‰ and 15°C, respectively. The toxicity ranking of five metals was: Hg (EC(50) of 41 and 42 μg l(-1)) > Cu (120 and 81 μg l(-1)) > Ni (2,009 and 1,360 μg l(-1)) > Zn (3,024 and 3,897 μg l(-1)) > Pb (4,760 and 4,429 μg l(-1)) > Cd (15,052 and 7,541 μg l(-1)) for germination and germ tube elongation, respectively. The sensitivities to Cd, Cu and Ni were greater in germ tube elongation than in germination process. When tested against two different waste-water samples (processed animal and printed circuit board waste-water) values of EC(50) were between 21.29 and 32.02% for germination and between 5.33 and 8.98% for germ tube elongation. Despite differences in their chemical composition, the toxic effects of waste-water samples, as indicated by EC(50) values, did not differ significantly for the same endpoints. The CV range for both germination and germ tube elongation was between 4.61 and 37.69%, indicating high levels of precision of the tests. The results compare favourably with those from more established test procedures employing micro- and macroalgae. The advantages and potential limitations of the bioassay for the assessment of anthropogenic impacts on coastal ecosystems and commercial cultivation areas in near-shore environments are discussed.

  16. Mouse TEX14 is required for embryonic germ cell intercellular bridges but not female fertility.

    PubMed

    Greenbaum, Michael P; Iwamori, Naoki; Agno, Julio E; Matzuk, Martin M

    2009-03-01

    A conserved feature of germ cell cytokinesis is the formation of stable intercellular bridges between daughter cells. These intercellular bridges are seen in diverse species from Drosophila melanogaster to Homo sapiens and have been shown to have roles in communication of large numbers of germ cells. In testis expressed gene 14 (Tex14) knockout mice, intercellular bridges do not form during spermatogenesis, and male mice are sterile, demonstrating an essential role for intercellular bridges in postnatal spermatogenesis in mammals. Intercellular bridges also form between dividing germ cells in both male and female embryos. However, little is known about the formation or role of the embryonic intercellular bridges in mammals. In females, embryonic intercellular bridges have been proposed to have a role in development of the presumptive oocyte. Herein, we show that TEX14 is an essential component of male and female embryonic intercellular bridges. In addition, we demonstrate that mitotic kinesin-like protein 1 (MKLP1, official symbol KIF23), which we have discovered is a component of intercellular bridges during spermatogenesis, is also a component of male and female embryonic intercellular bridges. Germ cell intercellular bridges are readily identified by KIF23 immunofluorescence between the gonocytes and oogonia of control mice but are absent between germ cells of Tex14-null mice. Furthermore, by electron microscopy, intercellular bridges are present in all control newborn ovaries but are absent in the Tex14 knockout ovaries. Despite the absence of embryonic intercellular bridges in the Tex14-null mice, male mice initiate spermatogenesis, and female mice are fertile. Although fewer oocytes were present in Tex14-null neonatal ovaries, folliculogenesis was still active at 1 yr of age. Thus, while TEX14 and intercellular bridges have an essential role in postnatal spermatogenesis, they are not required in the embryo.

  17. RNAi Screen Identifies Novel Regulators of RNP Granules in the Caenorhabditis elegans Germ Line

    PubMed Central

    Wood, Megan P.; Hollis, Angela; Severance, Ashley L.; Karrick, Megan L.; Schisa, Jennifer A.

    2016-01-01

    Complexes of RNA and RNA binding proteins form large-scale supramolecular structures under many cellular contexts. In Caenorhabditis elegans, small germ granules are present in the germ line that share characteristics with liquid droplets that undergo phase transitions. In meiotically-arrested oocytes of middle-aged hermaphrodites, the germ granules appear to aggregate or condense into large assemblies of RNA-binding proteins and maternal mRNAs. Prior characterization of the assembly of large-scale RNP structures via candidate approaches has identified a small number of regulators of phase transitions in the C. elegans germ line; however, the assembly, function, and regulation of these large RNP assemblies remain incompletely understood. To identify genes that promote remodeling and assembly of large RNP granules in meiotically-arrested oocytes, we performed a targeted, functional RNAi screen and identified over 300 genes that regulate the assembly of the RNA-binding protein MEX-3 into large granules. Among the most common GO classes are several categories related to RNA biology, as well as novel categories such as cell cortex, ER, and chromosome segregation. We found that arrested oocytes that fail to localize MEX-3 into cortical granules display reduced oocyte quality, consistent with the idea that the larger RNP assemblies promote oocyte quality when fertilization is delayed. Interestingly, a relatively small number of genes overlap with the regulators of germ granule assembly during normal development, or with the regulators of solid RNP granules in cgh-1 oocytes, suggesting fundamental differences in the regulation of RNP granule phase transitions during meiotic arrest. PMID:27317775

  18. Spondyloepiphseal dysplasia congenita in siblings born to unaffected parents: ? germ line mosaicism

    SciTech Connect

    Mulla, W.; McDonald-McGinn, D.; Zackai, E.

    1994-09-01

    Germ line mosaicism has been used to explain the birth of more than one child affected with a dominantly inherited disorder born to unaffected parents. Furthermore, it has been confirmed clinically in families where recurrence in siblings was originally thought to be autosomal recessive, but were affected individuals have reproduced affected offspring. Firm evidence of germ line mosaicism using mutation analysis by molecular methods exists for some autosomal disorders. We present two siblings with spondyloepipheseal dysplasia congenita (SEDC) born to unaffected parents. This suggests the presence of germ line mosaicism in this entity. Patient 1 was born at 32 weeks gestation to a G1P1 Puerto Rican mother. The pregnancy was complicated by polyhydramnios. The neonate, a short-limbed dwarf, died at 15 hours of age from respiratory distress and a compromised thoracic cavity. Patient 2, the sibling of patient 1 was born at 37 weeks gestation after a pregnancy complicated by polyhydramnios and prenatal ultrasound diagnosis of short-limbed dwarfism. The diagnosis of SEDC was made and, after review of the sibling`s postmortem X-rays, it was felt that she was similarly affected. The family history reveals no history of dwarfism or consanguinity. The SEDC is described as an autosomal dominant form of dwarfism with variable presentation including some cases that have been lethal in the neonatal period. SEDC is now believed to represent a family of collagen II mutations. Sporadic cases that have arisen in families with no history have been ascribed to new heterozygous mutations. Other families in which SEDC and SEMD recurred without a family history most likely represent germ line mosaicism. In these cases molecular studies should be pursued to document a collagen II mutation. We believe that germ line mosaicism is the most plausible explanation for recurrence in our family.

  19. DDX4 (VASA) is conserved in germ cell development in marsupials and monotremes.

    PubMed

    Hickford, Danielle E; Frankenberg, Stephen; Pask, Andrew J; Shaw, Geoff; Renfree, Marilyn B

    2011-10-01

    DDX4 (VASA) is an RNA helicase expressed in the germ cells of all animals. To gain greater insight into the role of this gene in mammalian germ cell development, we characterized DDX4 in both a marsupial (the tammar wallaby) and a monotreme (the platypus). DDX4 is highly conserved between eutherian, marsupial, and monotreme mammals. DDX4 protein is absent from tammar fetal germ cells but is present from Day 1 postpartum in both sexes. The distribution of DDX4 protein during oogenesis and spermatogenesis in the tammar is similar to eutherians. Female tammar germ cells contain DDX4 protein throughout all stages of postnatal oogenesis. In males, DDX4 is in gonocytes, and during spermatogenesis it is present in spermatocytes and round spermatids. A similar distribution of DDX4 occurs in the platypus during spermatogenesis. There are several DDX4 isoforms in the tammar, resulting from both pre- and posttranslational modifications. DDX4 in marsupials and monotremes has multiple splice variants and polyadenylation motifs. Using in silico analyses of genomic databases, we found that these previously unreported splice variants also occur in eutherians. In addition, several elements implicated in the control of Ddx4 expression in the mouse, including RGG (arginine-glycine-glycine) and dimethylation of arginine motifs and CpG islands within the Ddx4 promoter, are also highly conserved. Collectively these data suggest that DDX4 is essential for the regulation of germ cell proliferation and differentiation across all three extant mammalian groups-eutherians, marsupials, and monotremes. PMID:21653890

  20. RNAi Screen Identifies Novel Regulators of RNP Granules in the Caenorhabditis elegans Germ Line.

    PubMed

    Wood, Megan P; Hollis, Angela; Severance, Ashley L; Karrick, Megan L; Schisa, Jennifer A

    2016-01-01

    Complexes of RNA and RNA binding proteins form large-scale supramolecular structures under many cellular contexts. In Caenorhabditis elegans, small germ granules are present in the germ line that share characteristics with liquid droplets that undergo phase transitions. In meiotically-arrested oocytes of middle-aged hermaphrodites, the germ granules appear to aggregate or condense into large assemblies of RNA-binding proteins and maternal mRNAs. Prior characterization of the assembly of large-scale RNP structures via candidate approaches has identified a small number of regulators of phase transitions in the C. elegans germ line; however, the assembly, function, and regulation of these large RNP assemblies remain incompletely understood. To identify genes that promote remodeling and assembly of large RNP granules in meiotically-arrested oocytes, we performed a targeted, functional RNAi screen and identified over 300 genes that regulate the assembly of the RNA-binding protein MEX-3 into large granules. Among the most common GO classes are several categories related to RNA biology, as well as novel categories such as cell cortex, ER, and chromosome segregation. We found that arrested oocytes that fail to localize MEX-3 into cortical granules display reduced oocyte quality, consistent with the idea that the larger RNP assemblies promote oocyte quality when fertilization is delayed. Interestingly, a relatively small number of genes overlap with the regulators of germ granule assembly during normal development, or with the regulators of solid RNP granules in cgh-1 oocytes, suggesting fundamental differences in the regulation of RNP granule phase transitions during meiotic arrest. PMID:27317775