Sample records for primary germ layers

  1. The serpin PN1 is a feedback regulator of FGF signaling in germ layer and primary axis formation.

    PubMed

    Acosta, Helena; Iliev, Dobromir; Grahn, Tan Hooi Min; Gouignard, Nadège; Maccarana, Marco; Griesbach, Julia; Herzmann, Svende; Sagha, Mohsen; Climent, Maria; Pera, Edgar M

    2015-03-15

    Germ layer formation and primary axis development rely on Fibroblast growth factors (FGFs). In Xenopus, the secreted serine protease HtrA1 induces mesoderm and posterior trunk/tail structures by facilitating the spread of FGF signals. Here, we show that the serpin Protease nexin-1 (PN1) is transcriptionally activated by FGF signals, suppresses mesoderm and promotes head development in mRNA-injected embryos. An antisense morpholino oligonucleotide against PN1 has the opposite effect and inhibits ectodermal fate. However, ectoderm and anterior head structures can be restored in PN1-depleted embryos when HtrA1 and FGF receptor activities are diminished, indicating that FGF signals negatively regulate their formation. We show that PN1 binds to and inhibits HtrA1, prevents degradation of the proteoglycan Syndecan 4 and restricts paracrine FGF/Erk signaling. Our data suggest that PN1 is a negative-feedback regulator of FGF signaling and has important roles in ectoderm and head development. PMID:25758225

  2. [Treatment of primary mediastinal germ cell tumors].

    PubMed

    Yoshitake, T; Itoyama, S

    1989-02-01

    Primary mediastinal germ cell tumors are clinically classified into mature (benign) teratomas and malignant germ cell tumors. Mature teratomas should be surgically excised after diagnosis, because unnecessary delay may result in the rupture of tumors or in malignant degeneration. The prognosis after surgical removal of tumor is good and there is no recurrence of tumor after complete excision. Malignant germ cell tumors are therapeutically classified into seminomatous and nonseminomatous germ cell tumors. Nonseminomatous germ cell tumors comprise immature teratoma, teratocarcinoma (malignant teratoma), embryonal carcinoma, yolk sac (endodermal sinus) tumor and choriocarcinoma. Treatments for patients with them require an multidisciplinary therapeutic approach with radiotherapy or chemotherapy combined with surgical intervention. The prognosis of patients with these tumors are poor, however seminomatous germ cell tumors have a better prognosis than that of nonseminomatous tumors, because they are responsive to radiotherapy or chemotherapy and long survivals over five years after treatment are not rare among them. An aggressive cisplatin-based combination chemotherapy is performed for patients with nonseminomatous tumors who have mostly the elevated serum levels of AFP or beta-HCG as tumor marker. The serum levels of tumor markers reflect precisely the biological behavior of nonseminomatous tumors. Patients with the normalised serum levels of tumor markers after an medical intervention may have a good long prognosis following radical resection of tumors, although the sustained high serum levels of tumor markers after treatment indicate a poor prognosis. Long survivals over five years after therapy are extremely rare among them. PMID:9301895

  3. Major derivatives of the ectoderm germ layer Primary neurulation: neural tube formation in the chick embryo (Part 1)

    E-print Network

    in the chick embryo (Part 1) #12;Primary neurulation: neural tube formation in the chick embryo (Part 2) #12;Neurulation in an amphibian embryo, showing early, middle, and late neurulae in each case (Part 1) #12;Neurulation in an amphibian embryo, showing early, middle, and late neurulae in each case (Part 2) #12

  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 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

  6. Zebrafish organizer development and germ-layer formation require nodal-related signals

    Microsoft Academic Search

    Benjamin Feldman; Michael A. Gates; Elizabeth S. Egan; Scott T. Dougan; Gabriela Rennebeck; Howard I. Sirotkin; Alexander F. Schier; William S. Talbot

    1998-01-01

    The vertebrate body plan is established during gastrulation, when cells move inwards to form the mesodermal and endodermal germ layers. Signals from a region of dorsal mesoderm, which is termed the organizer, pattern the body axis by specifying the fates of neighbouring cells,. The organizer is itself induced by earlier signals. Although members of the transforming growth factor-beta (TGF-beta) and

  7. 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 sophisticated adaptive mechanism created during the evolution of female reproduction. Our data indicate that the pool of primary follicles in adult human ovaries does not represent a static but a dynamic population of differentiating and regressing structures. An essential mission of such follicular turnover might be elimination of spontaneous or environmentally induced genetic alterations of oocytes in resting primary follicles. PMID:15115550

  8. Differences in Transcription Patterns between Induced Pluripotent Stem Cells Produced from the Same Germ Layer Are Erased upon Differentiation

    PubMed Central

    Pirozhkova, Iryna; Robert, Thomas; Guégan, Justine; Bilhou-Nabera, Chrystèle; Busato, Florence; Tost, Jörg; Carnac, Gilles; Laoudj-Chenivesse, Dalila; Lipinski, Marc; Vassetzky, Yegor

    2013-01-01

    Little is known about differences between induced pluripotent stem cells produced from tissues originating from the same germ layer. We have generated human myoblast-derived iPS cells by retroviral transduction of human primary myoblasts with the OCT3/4, SOX2, KLF4 and MYC coding sequences and compared them to iPS produced from human primary fibroblasts. When cultivated in vitro, these iPS cells proved similar to human embryonic stem cells in terms of morphology, expression of embryonic stemness markers and gene promoter methylation patterns. Embryonic bodies were derived that expressed endodermal, mesodermal as well as ectodermal markers. A comparative analysis of transcription patterns revealed significant differences in the gene expression pattern between myoblast- and fibroblast-derived iPS cells. However, these differences were reduced in the mesenchymal stem cells derived from the two iPS cell types were compared. PMID:23326377

  9. Effects of Wheat Germ Extract on the Severity and Systemic Symptoms of Primary Dysmenorrhea: A Randomized Controlled Clinical Trial

    PubMed Central

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

    2014-01-01

    Background: Primary dysmenorrhea is one of the most common disorders in women and the main cause of absenteeism from work and school. Objectives: Considering the anti-inflammatory properties of wheat germ, the present study examined the effects of wheat germ extract on the severity and systemic symptoms of primary dysmenorrhea. Patients and Methods: This triple-blinded clinical trial was performed on 80 employed women in hospitals affiliated with Hamadan University of Medical Sciences (Hamadan, IR Iran). Subjects were allocated to two groups of 45 patients. Three 400-mg capsules of wheat germ extract or placebo were used daily? between the 16th day of the menstrual cycle to the fifth day of the next menstrual cycle for two consecutive months. Pain intensity was measured by a visual analogue scale thrice a day and a four-point verbal rating scale was employed to assess systemic symptoms. Results: Pain severity decreased only in the wheat germ extract group (P < 0.001) and there was no statistically significant change in the placebo group. In the wheat germ extract group, the pain severity decreased from 4.701 at baseline to 1.120 at the second cycle. The reduction in total scores of systemic symptoms of dysmenorrhea was statistically significant only in the wheat germ extract group (P < 0.001) and there was not a statistically significant change in the placebo group. It revealed statistically significant differences in systemic symptoms associated with dysmenorrhea including fatigue, headache, and mood swings in experimental group. Conclusions: Wheat germ extract seems to be an effective treatment for dysmenorrhea and its systemic symptoms, probably because of its anti-inflammatory effects. PMID:25389490

  10. 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

  11. Multiresolution identification of germ layer components in teratomas derived from human and nonhuman primate embryonic stem cells

    Microsoft Academic Search

    Amina Chebira; John A. Ozolek; Carlos A. Castro; William G. Jenkinson; Mukta Gore; Ramamurthy Bhagavatula; Irina Khaimovich; Shauna E. Ormon; Christopher S. Navara; Meena Sukhwani; Kyle E. Orwig; Ahmi Ben-yehudah; Gerald Schatten; Gustavo K. Rohde; Jelena Kovacevic

    2008-01-01

    We propose a system for identification of germ layer components in teratomas derived from human and nonhuman primate embryonic stem cells. Tissue regeneration and repair, drug testing and discov- ery, the cure of genetic and developmental syndromes all may rest on the understanding of the biology and behavior of embryonic stem (ES) cells. Within the field of stem cell biology,

  12. Tsukushi Modulates Xnr2, FGF and BMP Signaling: Regulation of Xenopus Germ Layer Formation

    PubMed Central

    Morris, Samantha A.; Almeida, Alexandra D.; Tanaka, Hideaki; Ohta, Kunimasa; Ohnuma, Shin-ichi

    2007-01-01

    Background Cell-cell communication is essential in tissue patterning. In early amphibian development, mesoderm is formed in the blastula-stage embryo through inductive interactions in which vegetal cells act on overlying equatorial cells. Members of the TGF-? family such as activin B, Vg1, derrière and Xenopus nodal-related proteins (Xnrs) are candidate mesoderm inducing factors, with further activity to induce endoderm of the vegetal region. TGF-?-like ligands, including BMP, are also responsible for patterning of germ layers. In addition, FGF signaling is essential for mesoderm formation whereas FGF signal inhibition has been implicated in endoderm induction. Clearly, several signaling pathways are coordinated to produce an appropriate developmental output; although intracellular crosstalk is known to integrate multiple pathways, relatively little is known about extracellular coordination. Methodology/Principal Findings Here, we show that Xenopus Tsukushi (X-TSK), a member of the secreted small leucine rich repeat proteoglycan (SLRP) family, is expressed in ectoderm, endoderm, and the organizer during early development. We have previously reported that X-TSK binds to and inhibits BMP signaling in cooperation with chordin. We now demonstrate two novel interactions: X-TSK binds to and inhibits signaling by FGF8b, in addition to binding to and enhancement of Xnr2 signaling. This signal integration by X-TSK at the extracellular level has an important role in germ layer formation and patterning. Vegetally localized X-TSK potentiates endoderm formation through coordination of BMP, FGF and Xnr2 signaling. In contrast, X-TSK inhibition of FGF-MAPK signaling blocks ventrolateral mesoderm formation, while BMP inhibition enhances organizer formation. These actions of X-TSK are reliant upon its expression in endoderm and dorsal mesoderm, with relative exclusion from ventrolateral mesoderm, in a pattern shaped by FGF signals. Conclusions/Significance Based on our observations, we propose a novel mechanism by which X-TSK refines the field of positional information by integration of multiple pathways in the extracellular space. PMID:17925852

  13. 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

  14. 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.

  15. Differentiation of liver cells from human primordial germ cell-derived progenitors

    Microsoft Academic Search

    Bin Chen; Jianjun Shi; Junke Zheng; Ying Chen; Kai Wang; Qingzhang Yang; Xuejin Chen; Zhuqing Yang; Xiaofei Zhou; Youming Zhu; Jianxin Chu; Ailian Liu; Hui Z. Sheng

    2007-01-01

    In previous studies, progenitor embryoid body-derived (EBD) cells have been derived from human embryonic germ cells. These cells express lineage markers of three primary germ layers, although their potential to produce true fetal cells of various types has yet to be tested. To this end, we have transplanted EBD cells into the fetal sheep liver. We show that these cells

  16. Variation in the dorsal gradient distribution is a source for modified scaling of germ layers in Drosophila.

    PubMed

    Chahda, Juan Sebastian; Sousa-Neves, Rui; Mizutani, Claudia Mieko

    2013-04-22

    Specification of germ layers along the dorsoventral axis by morphogenetic gradients is an ideal model to study scaling properties of gradients and cell fate changes during evolution. Classical anatomical studies in divergent insects (e.g., flies and grasshoppers) revealed that the neuroectodermal size is conserved and originates similar numbers of neuroblasts of homologous identity. In contrast, mesodermal domains vary significantly in closely related Drosophila species. To further investigate the underlying mechanisms of scaling of germ layers across Drosophila species, we quantified the Dorsal (Dl)/NF-?B gradient, the main morphogenetic gradient that initiates separation of the mesoderm, neuroectoderm, and ectoderm. We discovered a variable range of Toll activation across species and found that Dl activates mesodermal genes at the same threshold levels in melanogaster sibling species. We also show that the Dl gradient distribution can be modulated by nuclear size and packing densities. We propose that variation in mesodermal size occurs at a fast evolutionary rate and is an important mechanism to define the ventral boundary of the neuroectoderm. PMID:23583556

  17. Clinical stage B non-seminomatous germ cell testis cancer: The Indiana University experience (1965–1989) using routine primary retroperitoneal lymph node dissection

    Microsoft Academic Search

    J. P. Donohue; J. A. Thornhill; R. S. Foster; R. G. Rowland; R. Bihrle

    1995-01-01

    Between 1965 and 1989, 1180 patients at Indiana University, U.S.A., underwent retroperitoneal lymph node dissection (RPLND) for non-seminomatous germ cell (NSGC) testis cancer of whom 638 cases had primary RPLND. A subset of 174 cases were considered clinical stage B (or II) before surgery (retroperitoneal nodal metastases by clinical staging). Surgery revealed that 23% (n = 41) had pathological stage

  18. Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging

    PubMed Central

    Feng, Chenlu; Qiu, Xiaoguang; Qian, Tianyi; Lin, Yan; Zhou, Jian; Sui, Binbin

    2015-01-01

    Objective To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system (CNS) germ cell tumors (GCTs). Methods DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic (ROC) curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve. Results A significant elevation in transfer constant (Ktrans) and extravascular extracellular space (Ve) (P=0.000), as well as a significant reduction in rate constant (Kep) (P=0.000) was observed in tumors. Ktrans, relative Ktrans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative Ktrans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value (PPV) of 95.8%, and negative predictive value (NPV) of 100%. Conclusions Relative Ktrans appeared promising in predicting tumor response to radiation therapy (RT). It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT. PMID:26157319

  19. Germ Tag

    NSDL National Science Digital Library

    American Association for the Advancement of Science

    2009-01-01

    In this version of tag, a large group of learners model how the body fights infection. Learners act as germs, as lymphocytes, and as the body's cells threatened by germs. After playing one round, subsequent rounds can use different numbers of germs and/or lymphocytes to see how the infection rate is changed. When learners set up a free account at Kinetic City, they can answer bonus questions at the end of the activity as a quick assessment. They can also keep track of their progress in all of the Kinetic City activities, and compare their progress to other participants worldwide.

  20. Ketamine Exposure in Early Development Impairs Specification of the Primary Germ Cell Layers

    PubMed Central

    Akeju, Oluwaseun; Davis-Dusenbery, Brandi N; Cassel, Seth H.; Ichida, Justin K.; Eggan, Kevin

    2014-01-01

    Preclinical and clinical evidence implicates N-methyl-D-aspartate receptor (NMDAr) signaling in early embryological development. However, the role of NMDAr signaling in early development has not been well studied. Here, we use a mouse embryonic stem cell model to perform a step-wise exploration of the effects of NMDAr signaling on early cell fate specification. We found that antagonism of the NMDAr impaired specification into the neuroectodermal and mesoendodermal cell lineages, with little or no effect on specification of the extraembryonic endoderm cell lineage. Consistent with these findings, exogenous NMDA promoted neuroectodermal differentiation. Finally, NMDAr antagonism modified expression of several key targets of TGF-? superfamily signaling, suggesting a mechanism for these findings. In summary, this study shows that NMDAr antagonism interferes with the normal developmental pathways of embryogenesis, and suggests that interference is most pronounced prior to neuroectodermal and mesoendodermal cell fate specification. PMID:24746641

  1. Non-primary layering in some Adirondack orthogneisses

    SciTech Connect

    Levy, R.; McLelland, J.; Ritter, A. (Colgate Univ., Hamilton, NY (United States). 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.

  2. Neonatal line as a linear evidence of live birth: Estimation of postnatal survival of a new born from primary tooth germs

    PubMed Central

    Janardhanan, Mahija; Umadethan, B; Biniraj, KR; Kumar, RB Vinod; Rakesh, S

    2011-01-01

    Background: The presence of neonatal line indicates live birth and it is possible to estimate the exact period of survival of the infant in days by measuring the amount of postnatal hard tissue formation, and thus can be an evidence to the brutal act of infanticide. Materials and Methods: Primary tooth germs of both the arches were removed from the sockets of an infant who died few days after birth. Ground sections were made with hard tissue microtome. Decalcified sections were made from the crown of primary right mandibular canine and the sections were stained with hematoxylin and eosin. To visualize the neonatal line, the sections were subjected to light mocroscopy, polarized microscopy and scanning electron microscopy. A developing permanent molar from a one and a half year old boy and ten fully developed deciduous molars were used as controls. Results: The ground sections of all the developing tooth germs showed the presence of neonatal line and the analysis of enamel showed six distinct cross striations along the enamel rod length indicating the period of survival of the baby to be six days which was later confirmed with the hospital records. Conclusion: Neonatal line could be used as an evidence of infanticide. Accurate detection of neonatal line with advanced techniques could rewrite this supplementary evidence of infanticide into substantial evidence. PMID:22022132

  3. Culture of porcine embryonic germ cells in serum-supplemented and serum-free conditions: the effects of serum and growth factors on primary and long-term culture.

    PubMed

    Petkov, Stoyan G; Anderson, Gary B

    2008-06-01

    Fetal bovine serum (FBS) is a commonly used medium supplement with variable and undefined composition, which presents problems in culture of pluripotent stem cells. The purpose of this study was to determine if FBS can be replaced with Knockout Serum Replacement (KSR), a defined medium supplement, and to examine the effects of FBS and growth factors on short- and long-term culture of pig embryonic germ cells (EGC). No significant differences were observed in total and mean colony areas in primary cultures between FBS- and KSR-supplemented medium (421 x 10(3) mum(2) vs. 395 x 10(3) microm(2), p = 0.68, n = 11, and 6375 microm(2) vs. 6407 microm(2), p = 0.885, respectively). Total and mean colony areas were significantly larger in KSR-supplemented medium compared with medium supplemented with KSR and growth factors (505 x 10(3) microm(2) vs. 396 x 10(3) microm(2), p = 0.016, n = 12, and 8769 microm(2) vs. 6513 microm(2), p = 0.003, respectively). The cultures proliferated for significantly higher numbers of passages in FBS-supplemented medium and in medium supplemented with KSR and growth factors compared with medium containing KSR alone (31.1 vs. 21.9, p = 0.004, n = 10, and 35.5 vs. 21.6, p = 002, n = 10, respectively). Porcine EGC maintained in serum-free conditions were positive for pluripotent stem cell markers, maintained stable karyotypes for up to 54 passages, and were capable of differentiating in vitro into cells from the three primary germ layers. These results will help improve and standardize culture of pluripotent stem cells in the pig. PMID:18373476

  4. 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)

  5. 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/?-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

  6. Small C-terminal Domain Phosphatase 3 Dephosphorylates the Linker Sites of Receptor-regulated Smads (R-Smads) to Ensure Transforming Growth Factor ? (TGF?)-mediated Germ Layer Induction in Xenopus Embryos.

    PubMed

    Sun, Guanni; Hu, Zhirui; Min, Zheying; Yan, Xiaohua; Guan, Zhenpo; Su, Hanxia; Fu, Yu; Ma, Xiaopeng; Chen, Ye-Guang; Zhang, Michael Q; Tao, Qinghua; Wu, Wei

    2015-07-10

    Germ layer induction is one of the earliest events shortly after fertilization that initiates body formation of vertebrate embryos. In Xenopus, the maternally deposited transcriptional factor VegT promotes the expression of zygotic Nodal/Activin ligands that further form a morphogen gradient along the vegetal-animal axis and trigger the induction of the three germ layers. Here we found that SCP3 (small C-terminal domain phosphatase 3) is maternally expressed and vegetally enriched in Xenopus embryos and is essential for the timely induction of germ layers. SCP3 is required for the full activation of Nodal/Activin and bone morphogenetic protein signals and functions via dephosphorylation in the linker regions of receptor-regulated Smads. Consistently, the linker regions of receptor-regulated Smads are heavily phosphorylated in fertilized eggs, and this phosphorylation is gradually removed when embryos approach the midblastula transition. Knockdown of maternal SCP3 attenuates these dephosphorylation events and the activation of Nodal/Activin and bone morphogenetic protein signals after midblastula transition. This study thus suggested that the maternal SCP3 serves as a vegetally enriched, intrinsic factor to ensure a prepared status of Smads for their activation by the upcoming ligands during germ layer induction of Xenopus embryos. PMID:26013826

  7. Alumina atomic layer deposition nanocoatings on primary diamond particles using a fluidized bed reactor

    E-print Network

    George, Steven M.

    Alumina atomic layer deposition nanocoatings on primary diamond particles using a fluidized bed]. Atomic layer deposition (ALD) is a nanocoating process that is an ideal method for such an application

  8. Characterisation and Germline Transmission of Cultured Avian Primordial Germ Cells

    PubMed Central

    Macdonald, Joni; Glover, James D.; Taylor, Lorna; Sang, Helen M.; McGrew, Michael J.

    2010-01-01

    Background Avian primordial germ cells (PGCs) have significant potential to be used as a cell-based system for the study and preservation of avian germplasm, and the genetic modification of the avian genome. It was previously reported that PGCs from chicken embryos can be propagated in culture and contribute to the germ cell lineage of host birds. Principal Findings We confirm these results by demonstrating that PGCs from a different layer breed of chickens can be propagated for extended periods in vitro. We demonstrate that intracellular signalling through PI3K and MEK is necessary for PGC growth. We carried out an initial characterisation of these cells. We find that cultured PGCs contain large lipid vacuoles, are glycogen rich, and express the stem cell marker, SSEA-1. These cells also express the germ cell-specific proteins CVH and CDH. Unexpectedly, using RT-PCR we show that cultured PGCs express the pluripotency genes c-Myc, cKlf4, cPouV, cSox2, and cNanog. Finally, we demonstrate that the cultured PGCs will migrate to and colonise the forming gonad of host embryos. Male PGCs will colonise the female gonad and enter meiosis, but are lost from the gonad during sexual development. In male hosts, cultured PGCs form functional gametes as demonstrated by the generation of viable offspring. Conclusions The establishment of in vitro cultures of germline competent avian PGCs offers a unique system for the study of early germ cell differentiation and also a comparative system for mammalian germ cell development. Primary PGC lines will form the basis of an alternative technique for the preservation of avian germplasm and will be a valuable tool for transgenic technology, with both research and industrial applications. PMID:21124737

  9. Morphological changes and germ layer formation in the porcine embryos from days 7-13 of development.

    PubMed

    Sun, Ruizhen; Lei, Lei; Liu, Shichao; Xue, Binghua; Wang, Jianyu; Wang, Jiaqiang; Shen, Jingling; Duan, Lian; Shen, Xinghui; Cong, Yimei; Gu, Yanli; Hu, Kui; Jin, Lianhong; Liu, Zhong-hua

    2015-04-01

    Morphogenesis and identification of embryonic differentiation in porcine embryos are crucial issues for developmental biology and laboratory animal science. The current paper presents a study on the asynchronous development of hatched porcine embryos from days 7 to 13 post-insemination. Examination of semi-thin sections of the hypoblast showed that it had characteristics similar to those of the mouse anterior visceral endoderm during embryonic disc formation. Also, a cavity appeared in the epiblast, which was similar to a mouse proamniotic cavity. With the gradual disappearance of Rauber's layer, the cavity opened and contacted the external environment directly, all of which formed the embryonic disc. To confirm the differentiation characteristics, we performed immunohistochemical analyses and showed that GATA6 was detected clearly in parietal endoderm cells during embryonic disc establishment. OCT4 was expressed in the inner cell mass (ICM) and trophoblast of hatched blastocysts and in the epiblast during formation of the embryonic disc. However, OCT4 showed comparatively decreased expression in the posterior embryonic disc, primitive streak and migrating cells. SOX2 was present in the ICM and epiblast. Therefore, both SOX2 and OCT4 can be used as markers of pluripotent cells in the porcine embryonic disc. At the start of gastrulation, staining revealed VIMENTIN in the posterior of the embryonic disc, primitive streak and in migrating cells that underlay the embryonic disc and was also expressed in epiblast cells located in the anterior primitive streak. Together with serial sections of embryos stained by whole mount immunohistochemistry, the mesoderm differentiation pattern was shown as an ingression movement that took place at the posterior of the embryonic disc and with bilateral migration along the embryonic disc borders. PMID:24229742

  10. Treatment Option Overview (Extragonadal Germ Cell Tumors)

    MedlinePLUS

    ... Professional Extragonadal Germ Cell Tumors Treatment Extragonadal Germ Cell Tumors Treatment (PDQ®) General Information About Extragonadal Germ Cell Tumors Key Points Extragonadal germ cell tumors form ...

  11. Physiological differences between neurons in layer 2 and layer 3 of primary visual cortex (V1) of alert macaque monkeys

    PubMed Central

    Gur, Moshe; Snodderly, D Max

    2008-01-01

    The physiological literature does not distinguish between the superficial layers 2 and 3 of the primary visual cortex even though these two layers differ in their cytoarchitecture and anatomical connections. To distinguish layer 2 from layer 3, we have analysed the response characteristics of neurons recorded during microelectrode penetrations perpendicular to the cortical surface. Extracellular responses of single neurons to sweeping bars were recorded while macaque monkeys performed a fixation task. Data were analysed from penetrations where cells could be localized to specific depths in the cortex. Although the most superficial cells (depth, 145–371 ?m; presumably layer 2) responded preferentially to particular stimulus orientations, they were less selective than cells encountered immediately beneath them (depth, 386–696 ?m; presumably layer 3). Layer 2 cells had smaller spikes, higher levels of ongoing activity, larger receptive field activating regions, and less finely tuned selectivity for stimulus orientation and length than layer 3 cells. Direction selectivity was found only in layer 3. These data suggest that layer 3 is involved in generating and transmitting precise, localized information about image features, while the lesser selectivity of layer 2 cells may participate in top-down influences from higher cortical areas, as well as modulatory influences from subcortical brain regions. PMID:18325976

  12. Formation of a large Vasa-positive germ granule and its inheritance by germ cells in the enigmatic Chaetognaths

    Microsoft Academic Search

    Danièle Carré; Chakib Djediat; Christian Sardet

    2002-01-01

    Chaetognaths (arrow worms) are abundant hermaphrodite marine organisms whose phylogenetic position amongst protostomes and deuterostomes is still debated. Ancient histological observations dating from a century ago described the presence in eggs of a large granule, presumed to be a germ plasm, and its probable inheritance in four primary germ cells (PGCs). Using videomicroscopy, electron microscopy and immunocytochemistry (labelling with anti-Vasa

  13. 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

  14. Dppa3 / Pgc7 / stellais a maternal factor and is not required for germ cell specification in mice

    E-print Network

    Bortvin, Alex

    Background: In mice, germ cells are specified through signalling between layers of cells comprising the primitive embryo. The function of Dppa3 (also known as Pgc7 or stella), a gene expressed in primordial germ cells at ...

  15. Scanning laser polarimetry of the retinal nerve fibre layer in primary open angle and capsular glaucoma

    Microsoft Academic Search

    Gábor Holló; Ildikó Süveges; Attila Nagymihály; Péter Vargha

    1997-01-01

    AIMSTo evaluate the clinical value of scanning laser polarimetry with the nerve fibre analyser type II in primary open angle glaucoma (POAG) and capsular glaucoma.METHODSScanning laser polarimetry was performed on one eye of 30 patients suffering from POAG, 25 patients suffering from capsular glaucoma, and on 35 healthy control subjects. The retinal nerve fibre layer (RNFL) thickness values were compared

  16. Genetics of germ cell development

    E-print Network

    Lesch, Bluma J.

    The germ line represents a continuous cellular link between generations and between species, but the germ cells themselves develop in a specialized, organism-specific context. The model organisms Caenorhabditis elegans, ...

  17. 15 INTRACRANIAL GERM CELL TUMORS

    Microsoft Academic Search

    J Bjornsson; B Scheithauer; H Okazakl; R W Leech

    1984-01-01

    Intracranial germ cell tumors are a heterogeneous group of lesions which occur in children and adults. Within the classification of intracranial germ cell tumors, there are a variety of different tumor types which carry different prognoses. The diagnosis of an intracranial germ cell tumor usually requires histological informa- tion, but a subgroup of tumors will secrete specific tumor markers, including

  18. Germs and the Body

    NSDL National Science Digital Library

    Science Netlinks

    2002-08-01

    This Science NetLinks lesson explores germs, where they exist, and how they can affect the body. It also addresses a common misconception that students of all ages may have - that factors important to health are beyond their personal control. In studying bacteria, students will also learn preventative measures they can take to stay healthy.

  19. Callosal connections of the ferret primary auditory cortex

    Microsoft Academic Search

    M. N. Wallace; Morag S. Harper

    1997-01-01

    The callosal connections of ferret auditory cortex were studied by making multiple injections of wheat germ agglutinin-horseradish\\u000a peroxidase into the middle ectosylvian gyrus or by packing crystals of horseradish peroxidase into the transected corpus callosum.\\u000a The primary area (AI) had strong callosal connections that arose from somata mainly located in layer III. Other layers contained\\u000a sparsely distributed cells that projected

  20. Primordial Germ Cells in Mice

    PubMed Central

    Saitou, Mitinori; Yamaji, Masashi

    2012-01-01

    Germ cell development creates totipotency through genetic as well as epigenetic regulation of the genome function. Primordial germ cells (PGCs) are the first germ cell population established during development and are immediate precursors for both the oocytes and spermatogonia. We here summarize recent findings regarding the mechanism of PGC development in mice. We focus on the transcriptional and signaling mechanism for PGC specification, potential pluripotency, and epigenetic reprogramming in PGCs and strategies for the reconstitution of germ cell development using pluripotent stem cells in culture. Continued studies on germ cell development may lead to the generation of totipotency in vitro, which should have a profound influence on biological science as well as on medicine. PMID:23125014

  1. Adherence of Candida albicans germ tubes to plastic: ultrastructural and molecular studies of fibrillar adhesins.

    PubMed Central

    Tronchin, G; Bouchara, J P; Robert, R; Senet, J M

    1988-01-01

    Germ tubes of Candida albicans produced an additional fibrillar surface layer responsible for enhanced adherence to plastic. The correlation between germination of C. albicans and adherence of germ tubes to a plastic matrix led us to consider the existence of germ tube-specific adhesive components involved in the attachment process. Using concanavalin A-sensitized latex microspheres, we first detected extracellular molecules on the plastic surface after removal of the adherent germ tubes. Electron microscopy confirmed that fibrils of the germ tube involved in cell-substratum interconnections were retained on the plastic surface. Cytochemistry with concanavalin A-gold labeling demonstrated that these fibrillar structures contained mannoproteins. Dithiothreitol and iodoacetamide treatment of washed plastic allowed us to further characterize these fibrillar adhesins. Through analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two components with molecular weights (MWs) of 68,000 and 60,000 were detected on the plastic surface. The 68,000-MW component appeared to be one of the major constituents of the germ tube surface layers. Biosynthetic labeling experiments performed with L-[35S]methionine revealed two additional proteins: a high-MW component (greater than 200,000), and a 200,000-MW component. These four proteins, strongly labeled on the plastic surface and on the germ tube cell wall layers, were in contrast slightly labeled or even nonidentified in the culture supernatant, suggesting their involvement in germ tube adherence. Images PMID:3294182

  2. Analytic surface germs with minimal Pythagoras number

    Microsoft Academic Search

    José F. Fernando; F. Ciencias Matematicas

    2003-01-01

    We determine all complete intersection surface germs whose Pythagoras number is 2, and find that they are all embedded in R3 and have the property that every positive semidefinite analytic function germ is a sum of squares of analytic function germs. In addition, we discuss completely these properties for mixed surface germs in R3. Finally, we find in higher embedding

  3. 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.

  4. Superficial layer pyramidal cells communicate heterogeneously between multiple functional domains of cat primary visual cortex

    PubMed Central

    Martin, Kevan A. C.; Roth, Stephan; Rusch, Elisha S.

    2014-01-01

    The axons of pyramidal neurons in the superficial layers of the neocortex of higher mammals form lateral networks of discrete clusters of synaptic boutons. In primary visual cortex the clusters are reported to link domains that share the same orientation preferences, but how individual neurons contribute to this network is unknown. Here we performed optical imaging to record the intrinsic signal, which is an indirect measure of neuronal firing, and determined the global map of orientation preferences in the cat primary visual system. In the same experiment, single cells were recorded and labelled intracellularly. We found that individual axons arborise within the retinotopic representation of the classical receptive field, but their bouton clusters were not aligned along their preferred axis of orientation along the retinotopic map. Axon clusters formed in a variety of different orientation domains, not just the like-orientation domains. This topography and heterogeneity of single-cell connectivity provides circuits for normalization and context-dependent feature processing of visual scenes. PMID:25341917

  5. Layer Specific Sharpening of Frequency Tuning by Selective Attention in Primary Auditory Cortex

    PubMed Central

    O'Connell, Monica Noelle; Barczak, Annamaria; Schroeder, Charles E.

    2014-01-01

    Recent electrophysiological and neuroimaging studies provide converging evidence that attending to sounds increases the response selectivity of neuronal ensembles even at the first cortical stage of auditory stimulus processing in primary auditory cortex (A1). This is achieved by enhancement of responses in the regions that process attended frequency content, and by suppression of responses in the surrounding regions. The goals of our study were to define the extent to which A1 neuronal ensembles are involved in this process, determine its effect on the frequency tuning of A1 neuronal ensembles, and examine the involvement of the different cortical layers. To accomplish these, we analyzed laminar profiles of synaptic activity and action potentials recorded in A1 of macaques performing a rhythmic intermodal selective attention task. We found that the frequency tuning of neuronal ensembles was sharpened due to both increased gain at the preferentially processed or best frequency and increased response suppression at all other frequencies when auditory stimuli were attended. Our results suggest that these effects are due to a frequency-specific counterphase entrainment of ongoing delta oscillations, which predictively orchestrates opposite sign excitability changes across all of A1. This results in a net suppressive effect due to the large proportion of neuronal ensembles that do not specifically process the attended frequency content. Furthermore, analysis of laminar activation profiles revealed that although attention-related suppressive effects predominate the responses of supragranular neuronal ensembles, response enhancement is dominant in the granular and infragranular layers, providing evidence for layer-specific cortical operations in attentive stimulus processing. PMID:25471586

  6. Extragonadal Germ Cell Cancer (EGC)

    MedlinePLUS

    ... germ cells are first seen outside of the embryo in the yolk sac. At about 4 to ... weeks of development, these cells migrate into the embryo where they populate the developing testes or ovaries. ...

  7. Germ cell development in Meishan and White Composite gilts.

    PubMed

    McCoard, Susan A; Wise, Thomas H; Ford, J Joe

    2003-05-15

    This study compared dynamics of the germ cell population in two swine breeds that differ in prolifacy, White Composite (WC) and Meishan (MS), during fetal and neonatal life and in mature sows. Germ cell populations developed in a similar pattern in these two diverse breeds during fetal life. Maximal germ cell number was observed at 90 days postcoitum (dpc) in both WC and MS gilts, and substantial oogonial apoptosis was evident thereafter with approximately 30% of maximal numbers present at 25 days postpartum (dpp). Neither gilt nor sow germ cell number was correlated with maternal ovulation rate. Postnatal MS gilts had larger pools of primordial follicles and consistently greater proportions and numbers of primary and secondary follicles compared to postnatal WC gilts, indicative of enhanced follicular recruitment and primordial follicle activation. Occasional antral follicles were present in MS ovaries by 25 dpp and numerous surface follicles were observed at 56 dpp in MS but not WC ovaries, indicative of more rapid ovarian maturation and early onset of puberty. Total germ cell number is unlikely to influence or to predict subsequent ovulation rate. These observations highlight important developmental events during late fetal and early postnatal life that prepare the ovarian environment for early onset of puberty and subsequent ovulation in MS gilts. PMID:12654530

  8. Transplantation of fetal germ cells.

    PubMed

    Gosden, R G

    1992-04-01

    Oogonial stem cells are short-lived and endow the ovary with its lifetime store of follicles during fetal life. No compensatory mechanisms exist to replace germ cells that are lost for whatever reason after birth. Fetal germ cells and the abundant primordial follicles of immature animals can be successfully stored at low temperatures and transplanted to hosts to generate normal ovulatory cycles. Sterilized hosts are restored to fertility. Such results suggest that the abundant reserves of germ cells in the ovaries of human abortuses offer opportunities for treating patients whose sterility is due to afollicular ovaries uncomplicated by autoimmune disease. The prospects for this treatment depend largely on the vigilance of the recipient's immune system and public attitudes to a radical treatment, though one that promises to overcome sterility and hypoestrogenism in women with either premature menopause or gonadal dysgenesis. PMID:1627926

  9. Kif18a is specifically required for mitotic progression during germ line development.

    PubMed

    Czechanski, Anne; Kim, Haein; Byers, Candice; Greenstein, Ian; Stumpff, Jason; Reinholdt, Laura G

    2015-06-15

    Genome integrity in the developing germ line is strictly required for fecundity. In proliferating somatic cells and in germ cells, there are mitotic checkpoint mechanisms that ensure accurate chromosome segregation and euploidy. There is growing evidence of mitotic cell cycle components that are uniquely required in the germ line to ensure genome integrity. We previously showed that the primary phenotype of germ cell deficient 2 (gcd2) mutant mice is infertility due to germ cell depletion during embryogenesis. Here we show that the underlying mutation is a mis-sense mutation, R308K, in the motor domain of the kinesin-8 family member, KIF18A, a protein that is expressed in a variety of proliferative tissues and is a key regulator of chromosome alignment during mitosis. Despite the conservative nature of the mutation, we show that its functional consequences are equivalent to KIF18A deficiency in HeLa cells. We also show that somatic cells progress through mitosis, despite having chromosome alignment defects, while germ cells with similar chromosome alignment defects undergo mitotic arrest and apoptosis. Our data provide evidence for differential requirements for chromosome alignment in germ and somatic cells and show that Kif18a is one of a growing number of genes that are specifically required for cell cycle progression in proliferating germ cells. PMID:25824710

  10. Dazl regulates mouse embryonic germ cell development

    E-print Network

    Gill, Mark E

    2010-01-01

    In the mouse, germ cells can undergo differentiation to become either oocytes or spermatozoa in response to sex of their gonadal environment. The nature of the germ cell-intrinsic aspects of this signaling have not been ...

  11. Treatment Option Overview (Ovarian Germ Cell Tumors)

    MedlinePLUS

    ... ovarian germ cell tumor are swelling of the abdomen or vaginal bleeding after menopause. Ovarian germ cell ... if you have either of the following: Swollen abdomen without weight gain in other parts of the ...

  12. Testicular germ cell tumours: predisposition genes and the male germ cell niche

    Microsoft Academic Search

    Duncan Gilbert; Elizabeth Rapley; Janet Shipley

    2011-01-01

    Testicular germ cell tumours (TGCTs) of adults and adolescents are putatively derived from primordial germ cells or gonocytes. Recently reported genome-wide association studies implicate six gene loci that predispose to TGCT development. Remarkably, the functions of proteins encoded by genes within these regions bridge our understanding between the pathways involved in primordial germ cell physiology, male germ cell development and

  13. Feulgen-DNA changes in the germ cells of the male vole (Microtus agrestis) during their development

    E-print Network

    Boyer, Edmond

    Feulgen-DNA changes in the germ cells of the male vole (Microtus agrestis) during their development DNA in round spermatids of voles is approximately a quarter of that in primary spermatocytes of germ cell degeneration (Esnault et al., 1964). Testis activity in the vole (Microtus agrestis

  14. CHURNING CORN GERM DISPERSIONS TO SEPARATE OIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Processes are in pre-commercial stages of development, for separating corn germ prior to fermentation in a dry grind plant. Oil is currently removed from dry mill germ or wet mill germ by crushing for $35-45/ton or by hexane extraction for $20-40/ton (1). These costs, as well as the capital to bu...

  15. iBioSeminar: Germ Cell Development

    NSDL National Science Digital Library

    Ruth Lehmann (New York University School of Medicine; )

    2009-07-01

    When an egg is fertilized, two distinct groups of cells are formed; the somatic cells which give rise to all the structures in body and will ultimately die, and the primordial germ cells which become germ line stem cells that produce sperm and egg and thus, can give rise to another generation. Hence, germ cells are responsible for the maintenance of a species.

  16. Future of germ cell cytogenetics.

    PubMed

    Preston, R J

    1994-01-01

    The celebration of the 25th Anniversary of the Environmental Mutagen Society provides an excellent opportunity to assess the status of research in a broad range of areas, with an emphasis on the directions in which they are going. This chapter concentrates on the analysis of chromosomal alterations in mammalian germ cells. The future developments in germ cell cytogenetics research will build heavily upon techniques developed over the past 25 years. With these it is possible to assess numerical and structural alterations in the male in differentiating spermatogonia, spermatocytes, and post-meiotic cells (at the first cleavage division) and for the female in oocytes and the zygote. The most predictable advances will be in the identification of specific alterations through FISH of interphase spermatozoa in humans and further improvements with the human sperm/hamster egg in vitro fertilization technique. Of particular importance is the fact that this will allow for the study of effects in human germ cells. From a more speculative viewpoint it might be possible to assess the role of particular genomic organization on genetic outcomes by direct observation; these might include genomic imprinting and the visual separation of male and female genomes. The overall aim of germ cell cytogenetic studies will remain as improving our ability to identify and estimate the true genetic risk in humans. PMID:8162909

  17. 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…

  18. The Effect of Tertiary Butyl Alcohol on the Resistance of the Dry Product Layer During Primary Drying

    Microsoft Academic Search

    Kasra Kasraian; Patrick P. DeLuca

    1995-01-01

    The addition of low concentrations of tertiary butyl alcohol (TBA) (3–10% w\\/v) was shown to influence the crystal habit of ice by causing the formation of needle-shaped ice crystals. The sublimation of these needle-shaped ice crystals resulted in a dry product layer with little resistance. Using a microbalance technique it was shown that the primary drying stage for 5% w\\/v

  19. Changes in retinal nerve fibre layer, optic nerve head morphology, and visual field after acute primary angle closure

    Microsoft Academic Search

    C C A Sng; J S L See; C S Ngo; M Singh; Y-H Chan; M C Aquino; A M Tan; N Shabana; P T K Chew; PTK Chew

    2011-01-01

    Aims\\/PurposeTo determine and correlate the long-term changes in retinal nerve fibre layer (RNFL) thickness, optic nerve head (ONH) morphology, and visual fields after a single episode of acute primary angle closure (APAC).MethodsThis was a cross-sectional comparative study of patients at National University Hospital (Singapore) from 2000 to 2006 after an episode of unilateral APAC. The peripapillary and macular RNFL were

  20. [Effects of formaldehyde on germ cells of male mice].

    PubMed

    Tang, Mingde; Xie, Ying; Yi, Yizhen; Wang, Wei

    2003-11-01

    General toxicity and genetic materials damage of formaldehyde on germ cells in different stages was studied. In order to discover the toxicity mechanism of formaldehyde on germ cells and the biomarkers of effect after the presence of damage in germ cells and the estimation index, the relationships between the damage of germ cells and the MDA, SDH activity and Cu and Zn. in testicle tissue were investigated. Male mice exposed to formaldehyde by i.p. for 5 days. Formaldehyde doses were: 0.20 mg/kg, 2.00 mg/kg, 20.00 mg/kg. Mice were killed at the 6th day and the 14th day. HE staining was used to study the pathological changes happened in testicle tissue. In order to study the changes in sperm, the sperms and the abnormality of the sperm's heads were observed. In order to study the damage of the genetic material in the germ cells, the frequencies of sister chromosome exchanges and the frequencies of MN cells were studied. MDA was measured by MDA diagnosis box. Copper and zinc were determined by FAAS. US was used to determine the SDH activity in serum and testicle tissue. The results showed that: The main pathological changes in testicle tissue of formaldehyde groups were degeneration; The sperm quantity was decreased and the sperm heads deformation ratio was increased in all formaldehyde groups; There were a significant increase of MN ratio in early spermatogenic cells and SCE ratio in medial and high dose groups; The MDA in testicle tissue significant increased in high dose group. The SDH activity in testicle tissue was declined in all formaldehyde groups; There were a significant decline of copper and zinc in testicle tissue in high dose group. It is suggested that: Formaldehyde could induce genetic materials in spermatogone, primary spermatocyte and caused degeneration and necrosis in secondary spermatocyte, spermatogenic cell, sperm; The damage of LPO, decline of copper and zinc and SDH activity in mice's testicle tissue could be caused by formaldehyde; The effect of lipid peroxidation may be one of the toxicity mechanisms of formaldehyde on genetic materials; SDH is the biomarkers of effect after the toxicity effects induced by formaldehyde on germ cells appeared; Testing the sperm heads deformation ratio is the estimation index that can be used to judge the general toxicity of germ cells and the damage on their genetic materials of formaldehyde. PMID:14963899

  1. Mixed nonseminomatous germ cell tumor presenting as a subcutaneous tissue mass.

    PubMed

    Maubec, Eve; Avril, Marie-Françoise; Duvillard, Pierre; Leclère, Jérome; Caë, Ariane Le; Crickx, Béatrice; Theodore, Christine

    2006-12-01

    Extragonadal germ cell tumors most commonly arise in the midline of the retroperitoneum or the mediastinum. Primary tumors involving the skin are very rare. Only one case of malignant primary germ cell tumor located in the skin has been reported. We present the case of a 44-year-old white man with a primary subcutaneous mixed nonseminomatous germ cell tumor. This man had a long-lasting subcutaneous lump of the breast, which became painful. Surgery revealed 3 juxtaposed nodules. Microscopic examination showed a mixed germ cell tumor with a 90% immature teratoma component and a 10% embryonal carcinoma component. Testicular ultrasound and computed tomography of the chest, abdomen, pelvis, and brain were normal. Serum human chorionic gonadotrophin, beta-human chorionic gonadotrophin, alpha-fetoprotein, and lactate dehydrogenase were within normal ranges. A further surgical excision was performed. The patient is presently alive with no evidence of disease after a follow-up of 7 years. Review of the literature indicates that primary cutaneous extragonadal germ cell tumors usually occur as cutaneous or subcutaneous solitary nodules or as ulcerated lesions. They mainly consist of mature teratomas in children. Only 2 cases have been reported in adults. PMID:17122498

  2. 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.

  3. 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.

  4. Primary, secondary instabilities and control of the rotating-disk boundary layer

    E-print Network

    3 Open-loop control General strategy Application to the rotating-disk boundary layer 4 Conclusions 280 stability: all perturbations are damped Rsc convective instability: spatial radial group velocity condition: 0(; R) = (0, ; R) with = 0 0,i convective instability

  5. 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. PMID:25953399

  6. [Germ cell and embryonal tumors].

    PubMed

    Reith, W; Mühl-Benninghaus, R; Simgen, A; Yilmaz, U

    2014-08-01

    Germ cell tumors, which constitute approximately 3-5% of tumors of the central nervous system (CNS), can be subdivided into germinomas, embryonal carcinomas, yolk sac tumors, choriocarcinomas, teratomas and mixed germ cell tumors. The diagnosis of intracranial germ cell tumor is based on the clinical symptoms, detection of tumor markers, such as alpha fetoprotein (AFP) and the beta subunit of human chorionic gonadotropin (beta-hCG) in blood and cerebrospinal fluid (CSF), magnetic resonance imaging (MRI) of the brain and spinal cord, CSF cytology and histology. The diagnosis of a secreting germ cell tumor, i.e. a non-germinoma, can be made by the determination of AFP and hCG as tumor markers. Germinomas are radiosensitive but are equally as sensitive to chemotherapy. Teratomas of the CNS are mostly diagnosed in newborns and infants. The most decisive role in the treatment of teratomas is played by as complete a resection as possible. Chemotherapy and irradiation play a subordinate role.Embryonal tumors, which constitute approximately 15-20% of CNS tumors, include medulloblastomas, primitive neuroectodermal tumors (PNET) of the CNS and the atypical teratoid rhabdoid tumor of the CNS. Medulloblastoma is the most common malignant brain tumor in childhood and adolescence. The incidence peak is the fifth year of life with a male predisposition in a ratio of 1.5:1. Medulloblastomas constitute 12-25% of all pediatric CNS tumors and 30-40% of pediatric tumors of the posterior cranial fossa. At the time of diagnosis evidence of dissemination in the CSF cavity is found in approximately 40% of patients. The extreme cell density makes medulloblastomas hyperdense in computed tomography (CT) and can therefore be differentiated from hypodense astrocytomas. The PNETs are histologically related to medulloblastomas, pineoblastomas, atypical teratoid rhabdoid tumors and peripheral neuroblastomas. They are relatively rare in children constituting less than 5% of supratentorial neoplasms. Patients are mostly clinically conspicuous due to macrocephalus and signs of brain pressure and/or seizures. In native CT the solid components of PNETs show a hyperdensity compared to the surrounding brain parenchyma probably due to the high cell density. Cysts and calcification are often detectable. The survival rate of children with CNS tumors has continuously increased in recent years. When corresponding clinical symptoms appear, such as headache, nausea or vomiting when fasting, all of which are evidence of increased intracranial pressure, MRI should be carried out as quickly as possible. Children should be treated in centers with departments of pediatric oncology and hematology and within the framework of studies. PMID:25119569

  7. Expression of Axolotl DAZL RNA, a Marker of Germ Plasm: Widespread Maternal RNA and Onset of Expression in Germ Cells Approaching the Gonad

    Microsoft Academic Search

    Andrew D. Johnson; Rosemary F. Bachvarova; Matthew Drum; Thomas Masi

    2001-01-01

    How germ cell specification occurs remains a fundamental question in embryogenesis. The embryos of several model organisms contain germ cell determinants (germ plasm) that segregate to germ cell precursors. In other animals, including mice, germ cells form in response to regulative mechanisms during development. To investigate germ cell determination in urodeles, where germ plasm has never been conclusively identified, we

  8. UNSW Embryology: movies of germ cell migration

    NSDL National Science Digital Library

    Dr. Mark Hill (University of New South Wales Anatomy)

    2007-12-31

    Timelapse movies showing GFP labeled primordial germ cells during migration in the mouse from Mark Hill''s site courtesy of Molyneaux KA (Molyneaux KA, Stallock J, Schaible K, Wylie C. [See Related Articles] Time-lapse analysis of living mouse germ cell migration. Dev Biol. 2001 Dec 15;240(2):488-98).

  9. Microencapsulation of wheat germ oil.

    PubMed

    Yazicioglu, Basak; Sahin, Serpil; Sumnu, Gulum

    2015-06-01

    Wheat germ oil (WGO) is beneficial for health since it is a rich source of omega-3, omega-6 and tocopherol. However, as it contains polyunsaturated fatty acids, it is prone to oxidation. The aim of this study was to encapsulate wheat germ oil and determine the effects of core to coating ratio, coating materials ratio and ultrasonication time on particle size distribution of emulsions and encapsulation efficiency (EE) and surface morphology of capsules. Maltodextrin (MD) and whey protein concentrate (WPC) at different ratios (3:1, 2:2, 1:3) were used as coating materials. Total solid content of samples was 40 % (w/w). Five core to coating ratios (1:8, 1:4, 1:2, 3:4, 1:1) were tried. Ultrasound was used at 320 W and 20 kHz for 2, 5, 10 min to obtain emulsions. Then, emulsions were freeze dried to obtain microcapsules. It was observed that, increasing WPC ratio in the coating resulted in higher encapsulation efficiency and smaller particle size. Microcapsules prepared with MD:WPC ratio of 1:3 were found to have higher EE (74.35-89.62 %). Increase in oil load led to decrease in EE. Thus 1:8 core to coating ratio gave better results. Increasing ultrasonication time also had a positive effect on encapsulation efficiency. PMID:26028741

  10. 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

  11. 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

  12. Delay-induced primary rhythmic behavior in a two-layer neural network.

    PubMed

    Guo, Shangjiang; Yuan, Yuan

    2011-01-01

    In this paper, we construct a two-layer feedback neural network to theoretically investigate the influence of symmetry and time delays on patterned rhythmic behaviors. Firstly, linear stability of the model is investigated by analyzing the associated transcendental characteristic equation. Next, by means of the symmetric bifurcation theory of delay differential equations coupled with representation theory of standard dihedral groups, we not only investigate the effect of synaptic delays of signal transmission on the pattern formation, but also obtain some important results about the spontaneous bifurcation of multiple branches of periodic solutions and their spatio-temporal patterns. Thirdly, based on the normal form approach and the center manifold theory, we derive the formula to determine the bifurcation direction and stability of Hopf bifurcating periodic solutions. Finally, some numerical examples and the corresponding numerical simulations are used to illustrate the effectiveness of the obtained results. PMID:20884171

  13. Assessment of Speech in Primary Cleft Palate by Two-layer Closure (Conservative Management)

    PubMed Central

    Jain, Harsha; Rao, Dayashankara; Sharma, Shailender; Gupta, Saurabh

    2012-01-01

    Treatment of the cleft palate has evolved over a long period of time. Various techniques of cleft palate repair that are practiced today are the results of principles learned through many years of modifications. The challenge in the art of modern palatoplasty is no longer successful closure of the cleft palate but an optimal speech outcome without compromising maxillofacial growth. Throughout these periods of evolution in the treatment of cleft palate, the effectiveness of various treatment protocols has been challenged by controversies concerning speech and maxillofacial growth. In this article we have evaluated the results of Pinto's modification of Wardill–Kilner palatoplasty without radical dissection of the levator veli palitini muscle on speech and post-op fistula in two different age groups in 20 patients. Preoperative and 6-month postoperative speech assessment values indicated that two-layer palatoplasty (modified Wardill–Kilner V-Y pushback technique) without an intravelar veloplasty technique was good for speech. PMID:23066454

  14. Germ-cell origin in the adult caecilian Ichthyophis glutinosus (Linn)

    Microsoft Academic Search

    B. R. Seshachar

    1937-01-01

    In Ichthyophis glutinosus, no residual spermatogonia traceable to primordial germ cells of the embryo are seen, the primary spermatogonia of each season being formed afresh. Their only source so far as the adult is concerned, is the lining of the collecting duct and its numerous branches which ramify in the testis. No evidences of their origin from the surface epithelial

  15. Germ cell development in the descended and cryptorchid testis and the effects of hormonal manipulation

    Microsoft Academic Search

    C. Ong; S. Hasthorpe; J. M. Hutson

    2005-01-01

    Germ cell development is an active process in normal testes during the first 4 years after birth, with transformation of the neonatal gonocytes into adult dark spermatogonia and then primary spermatocytes. The hormonal regulation of these changes is not fully understood, with evidence both for and against a role for gonadotrophins and androgens. Early surgical intervention in infancy aims to prevent

  16. Specifying and protecting germ cell fate.

    PubMed

    Strome, Susan; Updike, Dustin

    2015-06-23

    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

  17. 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

  18. Characterization of active ion transport across primary rabbit corneal epithelial cell layers (RCrECL) cultured at an air-interface

    Microsoft Academic Search

    Joan-En Chang-Lin; Kwang-Jin Kim; Vincent H. L. Lee

    2005-01-01

    Previously, we reported the development of a primary culture model of tight rabbit corneal epithelial cell layers (RCrECL) characterizing bioelectric parameters, morphology, cytokeratin, and passive permeability. In the present study, we specifically evaluated the active ion transport processes of RCrECL cultured from either pigmented or albino rabbits.Primary cultured RCrECL were grown at an air-interface on Clear–Snapwells™ precoated with collagen\\/fibronectin\\/laminin and

  19. Primary production within the sea-ice zone west of the Antarctic Peninsula: I—Sea ice, summer mixed layer, and irradiance

    NASA Astrophysics Data System (ADS)

    Vernet, Maria; Martinson, Douglas; Iannuzzi, Richard; Stammerjohn, Sharon; Kozlowski, Wendy; Sines, Karie; Smith, Ray; Garibotti, Irene

    2008-09-01

    In shelf waters of the western Antarctic Peninsula (wAP), with abundant macro- and micronutrients, water-column stability has been suggested as the main factor controlling primary production; freshwater input from sea-ice melting stabilizes the upper water column by forming a shallow summer mixed layer. Retreating sea ice in the spring and summer thus defines the area of influence, the sea-ice zone (SIZ) and the marginal ice zone (MIZ). A 12-year time series (1995-2006) was analyzed to address two main questions: (1) what are the spatial and temporal patterns in primary production; and (2) to what extent and in what ways is primary production related to sea-ice dynamics. Data were collected on cruises performed during January of each year, at the height of the growth season, within the region bounded by 64°S and 64°W to the north and 68°S and 66°W to the south. Average daily integrated primary production varied by an order of magnitude, from ˜250 to ˜1100 mg C m -2 d -1, with an average cruise primary production of 745 mg C m -2 d -1. A strong onshore-offshore gradient was evident along the shelf with higher production observed inshore. Inter-annual regional production varied by a factor of 7: maximum rates were measured in 2006 (1788 mg C m -2 d -1) and minimum in 1999 (248 mg C m -2 d -1). The results support the hypothesis that primary production in the wAP shelf is related to sea-ice dynamics. To first order, shallower summer mixed-layer depths in the shelf correlated with late sea retreat and primary production. Principal component analysis showed that high primary production in January was associated with enhanced shelf production toward the coast and in the south, explaining 63% of the variability in space and time. This first mode captured the inter-annual variability in regional production. Temporal variability in primary production (time series of anomalies defined for each location) showed spatial dependence: higher primary production correlated with shallow mixed-layer depths only at mid-shelf; in coastal and offshore waters, primary production correlated with deeper mixed layers. Thus, coastal primary production can show a non-linear relationship with summer mixed layers. Under conditions of large biomass (>20 mg chl a m -3) and shallow mixed-layer depth (e.g., 5 m) phytoplankton production becomes light limited. This limitation is reduced with a deepening of the summer mixed layer (e.g., 20 m). Dominance of diatoms and the ability to adapt and photosynthesize at higher light levels characterized the large phytoplankton blooms. No significant regional trend in primary production was detected within the 12-year series. We conclude that the regional average primary production on the wAP shelf is associated with shallow summer mixed layers in conjunction with late sea-ice retreat. An opposite relationship is observed for the highest production rates in coastal waters, associated with large biomass, where a deepening of the summer mixed layer relieves light limitation.

  20. Layer 4 in Primary Visual Cortex of the Awake Rabbit: Contrasting Properties of Simple Cells and Putative Feedforward Inhibitory Interneurons

    PubMed Central

    Zhuang, Jun; Stoelzel, Carl R.; Bereshpolova, Yulia; Huff, Joseph M.; Hei, Xiaojuan; Alonso, Jose-Manuel

    2013-01-01

    Extracellular recordings were obtained from two cell classes in layer 4 of the awake rabbit primary visual cortex (V1): putative inhibitory interneurons [suspected inhibitory interneurons (SINs)] and putative excitatory cells with simple receptive fields. SINs were identified solely by their characteristic response to electrical stimulation of the lateral geniculate nucleus (LGN, 3+ spikes at >600 Hz), and simple cells were identified solely by receptive field structure, requiring spatially separate ON and/or OFF subfields. Notably, no cells met both criteria, and we studied 62 simple cells and 33 SINs. Fourteen cells met neither criterion. These layer 4 populations were markedly distinct. Thus, SINs were far less linear (F1/F0 < 1), more broadly tuned to stimulus orientation, direction, spatial and temporal frequency, more sensitive to contrast, had much higher spontaneous and stimulus-driven activity, and always had spatially overlapping ON/OFF receptive subfields. SINs responded to drifting gratings with increased firing rates (F0) for all orientations and directions. However, some SINs showed a weaker modulated (F1) response sharply tuned to orientation and/or direction. SINs responded at shorter latencies than simple cells to stationary stimuli, and the responses of both populations could be sustained or transient. Transient simple cells were more sensitive to contrast than sustained simple cells and their visual responses were more frequently suppressed by high contrasts. Finally, cross-correlation between LGN and SIN spike trains confirmed a fast and precisely timed monosynaptic connectivity, supporting the notion that SINs are well suited to provide a fast feedforward inhibition onto targeted cortical populations. PMID:23843510

  1. Protamines in mammalian germ cell mutagenesis

    SciTech Connect

    Sega, G.A.

    1989-01-01

    In the development from stem cells to functional spermatozoa, the germ cells of all mammals progress through a series of similar stages. Many studies have been carried out in mice with a variety of chemical agents that have produced differential genetic sensitivity in the various germ-cell stages depending on the agent being tested. In studies of the genetic effects of chemical agents in mice, the exposure given to the animals (by injection, inhalation, skin application, etc.) is accurately known. However, in general, nothing is known about the molecular dose of the chemical that actually reaches the different germ-cell stages. In particular, the chemical mutagens ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), ethylene oxide (EtO) and acrylamide (AA) have all been shown, in genetic studies, to produce very many more dominant lethal mutations and heritable translocations in late spermatids and early spermatozoa than in other germ-cell stages in male mice. We have, subsequently, used all 4 of these chemical mutagens in radioactive form to find out where they are binding within the germ cells and to see what correlations may exist between the extent of chemical binding in different stages and the amount of induced genetic damage. 17 refs., 4 figs.

  2. 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

  3. Regionalized random germs by a classification for probabilistic watershed. Application

    E-print Network

    Angulo,Jesús

    Regionalized random germs by a classification for probabilistic watershed. Application random germs regionalized by a previous classification in order to use probabilistic watershed Probabilistic watershed was introduced by Angulo and Jeulin [1] to detect the contours of the widest

  4. 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.

  5. Turning Points in Science: Germ Theory

    NSDL National Science Digital Library

    Mary LeFever

    This resource guide from the Middle School Portal 2 project, written specifically for teachers, provides links to exemplary resources including background information, lessons, career information, and related national science education standards. Germ theory represents the culmination of the work of several individuals across time. Resources provided here will facilitate understanding of the early scientific community's concept of disease; the thinking that led to hypotheses relating germs to disease; the various observations and experiments that yielded information allowing for theorizing; the scientific community's reaction to and acceptance of the early investigators' findings; and the impacts of the theory on humanity.

  6. 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

    This software describes the transport and energy deposition of the passage of galactic cosmic rays in astronaut tissues during space travel, or heavy ion beams in patients in cancer therapy. Space radiation risk is a probability distribution, and time-dependent biological events must be accounted for physical description of space radiation transport in tissues and cells. A stochastic model can calculate the probability density directly without unverified assumptions about shape of probability density function. The prior art of transport codes calculates the average flux and dose of particles behind spacecraft and tissue shielding. Because of the signaling times for activation and relaxation in the cell and tissue, transport code must describe temporal and microspatial density of functions to correlate DNA and oxidative damage with non-targeted effects of signals, bystander, etc. These are absolutely ignored or impossible in the prior art. The GERM code provides scientists data interpretation of experiments; modeling of beam line, shielding of target samples, and sample holders; and estimation of basic physical and biological outputs of their experiments. For mono-energetic ion beams, basic physical and biological properties are calculated for a selected ion type, such as kinetic energy, mass, charge number, absorbed dose, or fluence. Evaluated quantities are linear energy transfer (LET), range (R), absorption and fragmentation cross-sections, and the probability of nuclear interactions after 1 or 5 cm of water equivalent material. In addition, a set of biophysical properties is evaluated, such as the Poisson distribution for a specified cellular area, cell survival curves, and DNA damage yields per cell. Also, the GERM code 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 in a selected material. The GERM code makes the numerical estimates of basic 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.

  7. 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...

  8. 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...

  9. From the Cover: Development without germ cells: The role of the germ line in zebrafish sex differentiation

    Microsoft Academic Search

    Krasimir Slanchev; Jürg Stebler; Guillermo de La Cueva-Méndez; Erez Raz

    2005-01-01

    The progenitors of the gametes, the primordial germ cells (PGCs) are typically specified early in the development in positions, which are distinct from the gonad. These cells then migrate toward the gonad where they differentiate into sperms and eggs. Here, we study the role of the germ cells in somatic development and particularly the role of the germ line in

  10. 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,…

  11. Male germ cell apoptosis: regulation and biology

    PubMed Central

    Shaha, Chandrima; Tripathi, Rakshamani; Mishra, Durga Prasad

    2010-01-01

    Cellular apoptosis appears to be a constant feature in the adult testis and during early development. This is essential because mammalian spermatogenesis is a complex process that requires precise homeostasis of different cell types. This review discusses the latest information available on male germ cell apoptosis induced by hormones, toxins and temperature in the context of the type of apoptotic pathway either the intrinsic or the extrinsic that may be used under a variety of stimuli. The review also discusses the importance of mechanisms pertaining to cellular apoptosis during testicular development, which is independent of exogenous stimuli. Since instances of germ cell carcinoma have increased over the past few decades, the current status of research on apoptotic pathways in teratocarcinoma cells is included. One other important aspect that is covered in this review is microRNA-mediated control of germ cell apoptosis, a field of research that is going to see intense activity in near future. Since knockout models of various kinds have been used to study many aspects of germ cell development, a comprehensive summary of literature on knockout mice used in reproduction studies is also provided. PMID:20403866

  12. Histopathology of pineal germ cell tumors.

    PubMed

    Vasiljevic, A; Szathmari, A; Champier, J; Fèvre-Montange, M; Jouvet, A

    2015-01-01

    Germ cell tumors (GCTs) classically occur in gonads. However, they are the most frequent neoplasms in the pineal region. The pineal location of GCTs may be caused by the neoplastic transformation of a primordial germ cell that has mismigrated. The World Health Organization (WHO) recognizes 5 histological types of intracranial GCTs: germinoma and non-germinomatous tumors including embryonal carcinoma, yolk sac tumor, choriocarcinoma and mature or immature teratoma. Germinomas and teratomas are frequently encountered as pure tumors whereas the other types are mostly part of mixed GCTs. In this situation, the neuropathologist has to be able to identify each component of a GCT. When diagnosis is difficult, use of recent immunohistochemical markers such as OCT(octamer-binding transcription factor)3/4, Glypican 3, SALL(sal-like protein)4 may be required. OCT3/4 is helpful in the diagnosis of germinomas, Glypican 3 in the diagnosis of yolk sac tumors and SALL4 in the diagnosis of the germ cell nature of an intracranial tumor. When the germ cell nature of a pineal tumor is doubtful, the finding of an isochromosome 12p suggests the diagnosis of GCT. The final pathological report should always be confronted with the clinical data, especially the serum or cerebrospinal fluid levels of ?-human chorionic gonadotropin (HCG) and alpha-fetoprotein. PMID:24726316

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

    PubMed Central

    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 3weeks 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.

  14. 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

  15. Early oogenesis in the bat Carollia perspicillata: Transient germ cell cysts and noncanonical intercellular bridges

    PubMed Central

    Lechowska, Agnieszka; Bilinski, Szczepan M.; Rasweiler, John J.; Cretekos, Chris J.; Behringer, Richard; Kloc, Malgorzata

    2012-01-01

    The ovaries of early embryos (40 days after fertilization) of the bat Carollia perspicillata contain numerous germ-line cysts, which are composed of 10 to 12 sister germ cells (cystocytes). The variability in the number of cystocytes within the cyst and between the cysts (that defies the Giardina rule) indicates that the mitotic divisions of the cystoblast are asynchronous in this bat species. The serial section analysis showed that the cystocytes are interconnected via intercellular bridges that are atypical, strongly elongated, short-lived, and rich in microtubule bundles and microfilaments. During the later stages of embryonic development (44–46 days after fertilization), the somatic cells penetrate the cyst, and their cytoplasmic projections separate individual oocytes. Separated oocytes surrounded by the single layer of somatic cells constitute the primordial ovarian follicles. The oocytes of C. perspicillata are similar to mouse oocytes and are asymmetric. In both species, this asymmetry is clearly recognizable in the localization of the Golgi complexes. The presence of germ-line cysts and intercellular bridges (although non-canonical) in the fetal ovaries of C. perspicillata indicate that the formation of germ-line cysts is an evolutionarily conserved phase in the development of the female gametes throughout the animal kingdom. PMID:21681920

  16. Cryopreservation of female germ cells and ovarian tissues for fertility preservation

    Microsoft Academic Search

    Shu Hashimoto; Nao Suzuki; Bunpei Ishizuka; Yoshiharu Morimoto

    To preserve the fertility of patients who undergo chemotherapy and\\/or radiotherapy, procedures for cryopreservation of female\\u000a germ cells have been investigated. Cyropreservation methods differ according to follicle stage because the mammalian ovary\\u000a contains a large number of oocytes at different growth stages. Follicles at very early stages, for example the primordial\\u000a and primary stages, are usually cryopreserved within ovarian cortical

  17. A Feedforward Inhibitory Circuit Mediates Lateral Refinement of Sensory Representation in Upper Layer 2/3 of Mouse Primary Auditory Cortex

    PubMed Central

    Li, Ling-yun; Ji, Xu-ying; Liang, Feixue; Li, Ya-tang; Xiao, Zhongju

    2014-01-01

    Sensory information undergoes ordered and coordinated processing across cortical layers. Whereas cortical layer (L) 4 faithfully acquires thalamic information, the superficial layers appear well staged for more refined processing of L4-relayed signals to generate corticocortical outputs. However, the specific role of superficial layer processing and how it is specified by local synaptic circuits remains not well understood. Here, in the mouse primary auditory cortex, we showed that upper L2/3 circuits play a crucial role in refining functional selectivity of excitatory neurons by sharpening auditory tonal receptive fields and enhancing contrast of frequency representation. This refinement is mediated by synaptic inhibition being more broadly recruited than excitation, with the inhibition predominantly originating from interneurons in the same cortical layer. By comparing the onsets of synaptic inputs as well as of spiking responses of different types of neuron, we found that the broadly tuned, fast responding inhibition observed in excitatory cells can be primarily attributed to feedforward inhibition originating from parvalbumin (PV)-positive neurons, whereas somatostatin (SOM)-positive interneurons respond much later compared with the onset of inhibitory inputs to excitatory neurons. We propose that the feedforward circuit-mediated inhibition from PV neurons, which has an analogous function to lateral inhibition, enables upper L2/3 excitatory neurons to rapidly refine auditory representation. PMID:25297094

  18. 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

    2015-03-24

    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

  19. The vertebrate tail bud: three germ layers from one tissue

    Microsoft Academic Search

    C. May Griffith; M. J. Wiley; Esmond J. Sanders

    1992-01-01

    The tail bud of amniote embryos comprises a mass of apparently undifferentiated mesenchymal cells located at the caudal limit of the embryo, representing the remains of Hensen's node and the primitive streak. These cells have the potential to give rise to a variety of different tissues including the posterior or ‘secondary’ neural tube, the tail gut, and somites and their

  20. A role for Lin28 in primordial germ cell development and germ cell malignancy

    PubMed Central

    West, Jason A.; Viswanathan, Srinivas R.; Yabuuchi, Akiko; Cunniff, Kerianne; Takeuchi, Ayumu; Park, In-Hyun; Sero, Julia E.; Zhu, Hao; Perez-Atayde, Antonio; Frazier, A. Lindsay; Surani, M. Azim; Daley, George Q.

    2009-01-01

    The rarity and inaccessibility of the earliest primordial germ cells (PGCs) in the mouse embryo thwarts efforts to investigate molecular mechanisms of germ cell specification. Stella marks the minute founder population of the germ lineage1,2. Here we differentiate mouse embryonic stem cells (ESCs) carrying a Stella transgenic reporter into putative PGCs in vitro. The Stella+ cells possess a transcriptional profile similar to embryo-derived PGCs, and like their counterparts in vivo, lose imprints in a time-dependent manner. Using inhibitory RNAs to screen candidate genes for effects on the development of Stella+ cells in vitro, we discovered that Lin28, a negative regulator of let-7 microRNA processing3-6, is essential for proper PGC development. We further show that Blimp1, a let-7 target and a master regulator of PGC specification7-9, can rescue the effect of Lin28-deficiency during PGC development, thereby establishing a mechanism of action for Lin28 during PGC specification. Over-expression of Lin28 promotes formation of Stella+ cells in vitro and PGCs in chimeric embryos, and is associated with human germ cell tumours. The differentiation of putative PGCs from ESCs in vitro recapitulates the early stages of gamete development in vivo, and provides an accessible system for discovering novel genes involved in germ cell development and malignancy. PMID:19578360

  1. Pressurized solvent extraction of wheat germ oil

    Microsoft Academic Search

    Nurhan Turgut Dunford; Minquan Zhang

    2003-01-01

    This study examined the pressurized solvent extraction of wheat germ oil. The effects of temperature (45–135 °C at 1500 psi), extraction time, sample size and solvent type on the extraction efficiency and oil quality were studied. Extraction efficiency of the normal-hexane was compared to that of the iso- and high purity-hexane, iso-propanol, ethanol and acetone. The extracts were analyzed for n-3

  2. Diversity and functional convergence of small noncoding RNAs in male germ cell differentiation and fertilization.

    PubMed

    García-López, Jesús; Alonso, Lola; Cárdenas, David B; Artaza-Alvarez, Haydeé; Hourcade, Juan de Dios; Martínez, Sergio; Brieño-Enríquez, Miguel A; Del Mazo, Jesús

    2015-05-01

    The small noncoding RNAs (sncRNAs) are considered as post-transcriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs, or rRNAs processing may also play important regulatory roles in spermatogenesis. By next-generation sequencing (NGS), we characterized the sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs), pubertal spermatogonia cells, and mature spermatozoa. To assess their potential transmission through the spermatozoa during fertilization, the sncRNAs of mouse oocytes and zygotes were also analyzed. Both, microRNAs and snoRNA-derived small RNAs are abundantly expressed in PGCs but transiently replaced by piRNAs in spermatozoa and endo-siRNAs in oocytes and zygotes. Exhaustive analysis of miRNA sequence variants also shows an increment of noncanonical microRNA forms along male germ cell differentiation. RNAs-derived from tRNAs and rRNAs interacting with PIWI proteins are not generated by the ping-pong pathway and could be a source of primary piRNAs. Moreover, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. Finally, computational analysis revealed their potential involvement in post-transcriptional regulation of mRNA transcripts suggesting functional convergence among different small RNA classes in germ cells and zygotes. PMID:25805854

  3. Emerging methods to generate artificial germ cells from stem cells.

    PubMed

    Zeng, Fanhui; Huang, Fajun; Guo, Jingjing; Hu, Xingchang; Liu, Changbai; Wang, Hu

    2015-04-01

    Germ cells are responsible for the transmission of genetic and epigenetic information across generations. At present, the number of infertile couples is increasing worldwide; these infertility problems can be traced to environmental pollutions, infectious diseases, cancer, psychological or work-related stress, and other factors, such as lifestyle and genetics. Notably, lack of germ cells and germ cell loss present real obstacles in infertility treatment. Recent research aimed at producing gametes through artificial germ cell generation from stem cells may offer great hope for affected couples to treat infertility in the future. Therefore, this rapidly emerging area of artificial germ cell generation from nongermline cells has gained considerable attention from basic and clinical research in the fields of stem cell biology, developmental biology, and reproductive biology. Here, we review the state of the art in artificial germ cell generation. PMID:25715792

  4. Entry of Mouse Embryonic Germ Cells into Meiosis

    Microsoft Academic Search

    A. McLaren; D. Southee

    1997-01-01

    Germ cells harvested from mouse embryonic genital ridges were mixed with disaggregated embryonic lung cells, and the reaggregates were cultured for 4–7 days. Germ cells derived from female embryos 10.5–13.5 days postcoitum (dpc) entered and progressed through meiotic prophasein vitroasin vivo,although with a 12- to 24-hr delay. If the cultures were maintained for 2–3 weeks, the germ cells developed into

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

    SciTech Connect

    Teng, Yincheng [Department of Gynecology and Obstetrics, The 6th People's Hospital, School of Medicine, Shanghai Jiao Tong University, 600 Yishan Road, Shanghai 200233 (China)] [Department of Gynecology and Obstetrics, The 6th People's Hospital, School of Medicine, Shanghai Jiao Tong University, 600 Yishan Road, Shanghai 200233 (China); Chen, Bin [Center for Developmental Biology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092 (China)] [Center for Developmental Biology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092 (China); Tao, Minfang, E-mail: Taomf@126.com [Department of Gynecology and Obstetrics, The 6th People's Hospital, School of Medicine, Shanghai Jiao Tong University, 600 Yishan Road, Shanghai 200233 (China)] [Department of Gynecology and Obstetrics, The 6th People's Hospital, School of Medicine, Shanghai Jiao Tong University, 600 Yishan Road, Shanghai 200233 (China)

    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.

  6. 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

  7. Spike Firing and IPSPs in Layer V Pyramidal Neurons during Beta Oscillations in Rat Primary Motor Cortex (M1) In Vitro

    PubMed Central

    Lacey, Michael G.; Gooding-Williams, Gerard; Prokic, Emma J.; Yamawaki, Naoki; Hall, Stephen D.; Stanford, Ian M.; Woodhall, Gavin L.

    2014-01-01

    Beta frequency oscillations (10–35 Hz) in motor regions of cerebral cortex play an important role in stabilising and suppressing unwanted movements, and become intensified during the pathological akinesia of Parkinson's Disease. We have used a cortical slice preparation of rat brain, combined with concurrent intracellular and field recordings from the primary motor cortex (M1), to explore the cellular basis of the persistent beta frequency (27–30 Hz) oscillations manifest in local field potentials (LFP) in layers II and V of M1 produced by continuous perfusion of kainic acid (100 nM) and carbachol (5 µM). Spontaneous depolarizing GABA-ergic IPSPs in layer V cells, intracellularly dialyzed with KCl and IEM1460 (to block glutamatergic EPSCs), were recorded at ?80 mV. IPSPs showed a highly significant (P< 0.01) beta frequency component, which was highly significantly coherent with both the Layer II and V LFP oscillation (which were in antiphase to each other). Both IPSPs and the LFP beta oscillations were abolished by the GABAA antagonist bicuculline. Layer V cells at rest fired spontaneous action potentials at sub-beta frequencies (mean of 7.1+1.2 Hz; n?=?27) which were phase-locked to the layer V LFP beta oscillation, preceding the peak of the LFP beta oscillation by some 20 ms. We propose that M1 beta oscillations, in common with other oscillations in other brain regions, can arise from synchronous hyperpolarization of pyramidal cells driven by synaptic inputs from a GABA-ergic interneuronal network (or networks) entrained by recurrent excitation derived from pyramidal cells. This mechanism plays an important role in both the physiology and pathophysiology of control of voluntary movement generation. PMID:24465488

  8. Temporal Germ Cell Development Strategy during Mixed Spermatogenesis within the Male Mediterranean Gecko, Hemidactylus turcicus

    E-print Network

    Sever, David M.

    collectively progress through the stages of spermatogenesis. The reptilian temporal model of germ cell these tubules (Russell et al., 1990). The reptilian germ cell development strategy, previously described

  9. Applying “Gold Standards” to In vitro-Derived Germ Cells

    PubMed Central

    Handel, Mary Ann; Eppig, John J.; Schimenti, John C.

    2015-01-01

    Germ cells are the ultimate stem cells and reports of their in vitro derivation generate excitement due to potential applications in reproductive medicine. To date there is no firm evidence that meiosis, the hallmark of gametogenesis, can be faithfully replicated outside the gonad. We propose benchmarks for evaluating in vitro derivation of germ cells, facilitating realization of their potential. PMID:24906145

  10. Cellular Mechanics of Germ Band Retraction in Drosophila

    PubMed Central

    Lynch, Holley E.; Crews, Sarah M.; Rosenthal, Brett; Kim, Elliott; Gish, Robert; Echiverri, Karl; Hutson, M. Shane

    2013-01-01

    Germ band retraction involves a dramatic rearrangement of the tissues on the surface of the Drosophila embryo. As germ band retraction commences, one tissue, the germ band, wraps around another, the amnioserosa. Through retraction the two tissues move cohesively as the highly elongated cells of the amnioserosa contract and the germ band moves so it is only on one side of the embryo. To understand the mechanical drivers of this process, we designed a series of laser ablations that suggest a mechanical role for the amnioserosa. First, we find that during mid retraction, segments in the curve of the germ band are under anisotropic tension. The largest tensions are in the direction in which the amnioserosa contracts. Second, ablating one lateral flank of the amnioserosa reduces the observed force anisotropy and leads to retraction failures. The other intact flank of amnioserosa is insufficient to drive retraction, but can support some germ band cell elongation and is thus not a full phenocopy of ush mutants. Another ablation-induced failure in retraction can phenocopy mys mutants, and does so by targeting amnioserosa cells in the same region where the mutant fails to adhere to the germ band. We conclude that the amnioserosa must play a key, but assistive, mechanical role that aids uncurling of the germ band. PMID:24135149

  11. Isolation and transplantation of sturgeon early-stage germ cells.

    PubMed

    Pšeni?ka, Martin; Saito, Taiju; Linhartová, Zuzana; Gazo, Ievgeniia

    2015-04-01

    We report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate a germline chimera as a potential tool for surrogate reproduction and gene banking. Cells were dissociated from testis, characterized by mostly spermatogonia, and from ovary, exclusively comprising oogonia and previtellogenic oocytes, of Acipenser baerii, using 0.3% trypsin (2 hours, 23 °C) dissolved in PBS, isotonic with blood plasma. The dissociated germ cells were sorted by Percoll gradient centrifugation followed by immunolabeling with germ cell-specific vasa antibody DDX4, while 10% to 30% Percoll solution contained 79.4% and 70.8% labeled testicular and ovarian cells. Sorted germ cells were transplanted into a cavity close to a presumptive genital ridge of newly hatched heterospecific Acipenser ruthenus larvae with fluorescein isothiocyanate-labeled endogenous primordial germ cells. The transplanted germ cells were randomly distributed in the body cavity through 30-day posttransplantation (dpt). Subsequently, the cells were organized into genital ridges 50 dpt and proliferated 90 dpt. The number of both transplanted and endogenous germ cells significantly increased from 18.1, 22.2, and 29.1 (30 dpt) to 108.5, 90.8, and 118.5 (90 dpt) in ovarian, testicular, and endogenous germ cells, respectively (P < 0.05). The efficiency of transplantation was 60% (counted 90 dpt). PMID:25559841

  12. EQUIVALENCE RELATIONS FOR TWO VARIABLE REAL ANALYTIC FUNCTION GERMS

    E-print Network

    that are not blow-analytically equivalent. The natural equivalence relations we first think of are the Cr coordinate analytic function germs. We say that f and g are Cr (right) equivalent if there is a local Cr equivalent, but not Cr+1 equivalent. In the family of germs Kt(x, y) = x4 + tx2 y2 + y4 , the phenomenon

  13. EDITORIAL INTRODUCTION [TO FEMALE GERM CELLS: BIOLOGY AND GENETIC RISK

    EPA Science Inventory

    This is an editorial introduction to the special issue of utation Research, titled, emale Germ Cells: Biology and Genetic isk, which is an attempt to present a collection of papers that emphasize the distinct properties of female germ cells and their characteristic response to mu...

  14. Cellular mechanics of germ band retraction in Drosophila.

    PubMed

    Lynch, Holley E; Crews, Sarah M; Rosenthal, Brett; Kim, Elliott; Gish, Robert; Echiverri, Karl; Hutson, M Shane

    2013-12-15

    Germ band retraction involves a dramatic rearrangement of the tissues on the surface of the Drosophila embryo. As germ band retraction commences, one tissue, the germ band, wraps around another, the amnioserosa. Through retraction the two tissues move cohesively as the highly elongated cells of the amnioserosa contract and the germ band moves so it is only on one side of the embryo. To understand the mechanical drivers of this process, we designed a series of laser ablations that suggest a mechanical role for the amnioserosa. First, we find that during mid retraction, segments in the curve of the germ band are under anisotropic tension. The largest tensions are in the direction in which the amnioserosa contracts. Second, ablating one lateral flank of the amnioserosa reduces the observed force anisotropy and leads to retraction failures. The other intact flank of amnioserosa is insufficient to drive retraction, but can support some germ band cell elongation and is thus not a full phenocopy of ush mutants. Another ablation-induced failure in retraction can phenocopy mys mutants, and does so by targeting amnioserosa cells in the same region where the mutant fails to adhere to the germ band. We conclude that the amnioserosa must play a key, but assistive, mechanical role that aids uncurling of the germ band. PMID:24135149

  15. Inverted Impacted Primary Maxillary Incisors: A Case Report

    PubMed Central

    Seraj, B.; Ghadimi, S.; Mighani, G.; Zare, H.; Rabbani, M.

    2012-01-01

    Tooth impaction rarely occurs in primary dentition. Most of the primary teeth impactions are seen in second molars. The purpose of this article is to present a 4-year-old girl with bilateral impaction of inverted primary maxillary central incisors which trauma had displaced their tooth germ before erupting. PMID:23066483

  16. Germ-line transformation of Arabidopsis lasiocarpa.

    PubMed

    Tague, B W

    2001-06-01

    In planta transformation methods have opened up the possibility of transforming plant species for which no regeneration protocols currently exist. In this study, the suitability of the germ-line transformation method developed for Arabidopsis thaliana was examined for four taxa in the Brassicaceae that have not been previously transformed: Arabidopsis griffithiana, Arabidopsis lasiocarpa, Arabidopsis petraea and Capsella bursa-pastoris. Numerous transformants were obtained for A. lasiocarpa. Transformation of A. lasiocarpa was confirmed at the phenotypic and molecular levels for stably transformed lines and for backcrossed lines segregating the T-DNA insert. Parameters affecting transformation efficiency of A. lasiocarpa were also explored. As with A. thaliana, sucrose and surfactant in the inoculation medium are required for high levels of transformation, although the suitable concentrations of these are different for A. lasiocarpa. Other components present in earlier versions of the inoculation medium had little effect on transformation efficiency. Vacuum infiltration (rather than simple floral dipping) led to higher rates of transformation and did not seriously affect seed production in A. lasiocarpa. Identification of species susceptible to germ-line transformation will aid in determining the factors important for applying this technology to more recalcitrant species. PMID:11437282

  17. How to make a human germ cell

    PubMed Central

    Cooke, Paul S; Nanjappa, Manjunatha K

    2015-01-01

    How the primordial germ cell (PGC) lineage, which eventually gives rise to spermatozoa in males and oocytes in females, is established in the developing mammalian embryo has been a critical topic in both developmental and reproductive biology for many years. There have been significant breakthroughs over the past two decades in establishing both the source of PGCs and the factors that regulate the specification of this lineage in mice,1 but our understanding of the factors that control PGC development in the human is rudimentary. The SRY-related HMG-box (SOX) family of transcription factors consists of 20 genes in humans and mice that are involved in the maintenance of pluripotency, male sexual development, and other processes. A recent paper in Cell has identified one member of this family, SOX17, as an essential factor for inducing the PGC lineage in humans.2 Surprisingly, this protein does not appear to have a role in PGC specification in mice. This work not only introduces a new and important player to the field of germ cell specification, but also emphasizes the uniqueness of human PGC development compared to more extensively studied mouse models. PMID:25791734

  18. Dynamic regulation of mitochondrial genome maintenance in germ cells.

    PubMed

    Kasashima, Katsumi; Nagao, Yasumitsu; Endo, Hitoshi

    2014-01-01

    Mitochondria play a crucial role in the development and function of germ cells. Mitochondria contain a maternally inherited genome that should be transmitted to offspring without reactive oxygen species-induced damage during germ line development. Germ cells are also involved in the mitochondrial DNA (mtDNA) bottleneck; thus, the appropriate regulation of mtDNA in these cells is very important for this characteristic transmission. In this review, we focused on unique regulation of the mitochondrial genome in animal germ cells; paternal elimination and the mtDNA bottleneck in females. We also summarized the mitochondrial nucleoid factors involved in various mtDNA regulation pathways. Among them, mitochondrial transcription factor A (TFAM), which has pleiotropic and essential roles in mtDNA maintenance, appears to have putative roles in germ cell regulation. PMID:24482608

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

    PubMed Central

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

    2014-01-01

    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 in how these animals can help in this research field. The review is not intended to be comprehensive – sea star reproduction has been studied 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. PMID:24648114

  20. 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. PMID:24648114

  1. Protein Interactions in Xenopus Germ Plasm RNP Particles

    PubMed Central

    Nijjar, Sarbjit; Woodland, Hugh R.

    2013-01-01

    Hermes is an RNA-binding protein that we have previously reported to be found in the ribonucleoprotein (RNP) particles of Xenopus germ plasm, where it is associated with various RNAs, including that encoding the germ line determinant Nanos1. To further define the composition of these RNPs, we performed a screen for Hermes-binding partners using the yeast two-hybrid system. We have identified and validated four proteins that interact with Hermes in germ plasm: two isoforms of Xvelo1 (a homologue of zebrafish Bucky ball) and Rbm24b and Rbm42b, both RNA-binding proteins containing the RRM motif. GFP-Xvelo fusion proteins and their endogenous counterparts, identified with antisera, were found to localize with Hermes in the germ plasm particles of large oocytes and eggs. Only the larger Xvelo isoform was naturally found in the Balbiani body of previtellogenic oocytes. Bimolecular fluorescence complementation (BiFC) experiments confirmed that Hermes and the Xvelo variants interact in germ plasm, as do Rbm24b and 42b. Depletion of the shorter Xvelo variant with antisense oligonucleotides caused a decrease in the size of germ plasm aggregates and loosening of associated mitochondria from these structures. This suggests that the short Xvelo variant, or less likely its RNA, has a role in organizing and maintaining the integrity of germ plasm in Xenopus oocytes. While GFP fusion proteins for Rbm24b and 42b did not localize into germ plasm as specifically as Hermes or Xvelo, BiFC analysis indicated that both interact with Hermes in germ plasm RNPs. They are very stable in the face of RNA depletion, but additive effects of combinations of antisense oligos suggest they may have a role in germ plasm structure and may influence the ability of Hermes protein to effectively enter RNP particles. PMID:24265795

  2. Current update of management of clinical stage I non seminomatous germ cell tumors of testis.

    PubMed

    Yuvaraja, T B

    2012-06-01

    The management of patients with testicular germ cell tumors (GCT) has evolved significantly over the past 30 years with cure rates approaching nearly 100% for low-stage disease and more than 80% for advanced disease. Controversy surrounds about ideal management of clinical stage I non seminomatous germ cell tumors (CS I NSGCT) of the testis due to multiple treatment options available with more or less equal efficacy. Nerve-sparing retroperitoneal lymph node dissection (RPLND), adjuvant chemotherapy with two cycles of bleomycin, etoposide, and cisplatin , or surveillance have all achieved long-term survival in nearly 100% of patients with clinical stage I NSGCT. Retroperitoneal lymph node dissection is still favoured as the therapy of choice for clinical stage I non-seminomatous germ cell tumors in many centres, but as risk factors for the primary tumor have become better understood, surveillance and risk-adapted therapy, including surveillance for low-risk patients and adjuvant chemotherapy for the high-risk group, is now being considered a therapeutic option. The objective of this study is to review current developments in the management of CS I NSGCT testis with emphasis on risk stratification and treatment recommendations. PMID:23730098

  3. 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.

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

    PubMed

    Tomes, N

    2000-02-01

    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

  5. 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

  6. Germ-line and somatic DICER1 mutations in pineoblastoma.

    PubMed

    de Kock, Leanne; Sabbaghian, Nelly; Druker, Harriet; Weber, Evan; Hamel, Nancy; Miller, Suzanne; Choong, Catherine S; Gottardo, Nicholas G; Kees, Ursula R; Rednam, Surya P; van Hest, Liselotte P; Jongmans, Marjolijn C; Jhangiani, Shalini; Lupski, James R; Zacharin, Margaret; Bouron-Dal Soglio, Dorothée; Huang, Annie; Priest, John R; Perry, Arie; Mueller, Sabine; Albrecht, Steffen; Malkin, David; Grundy, Richard G; Foulkes, William D

    2014-10-01

    Germ-line RB-1 mutations predispose to pineoblastoma (PinB), but other predisposing genetic factors are not well established. We recently identified a germ-line DICER1 mutation in a child with a PinB. This was accompanied by loss of heterozygosity (LOH) of the wild-type allele within the tumour. We set out to establish the prevalence of DICER1 mutations in an opportunistically ascertained series of PinBs. Twenty-one PinB cases were studied: Eighteen cases had not undergone previous testing for DICER1 mutations; three patients were known carriers of germ-line DICER1 mutations. The eighteen PinBs were sequenced by Sanger and/or Fluidigm-based next-generation sequencing to identify DICER1 mutations in blood gDNA and/or tumour gDNA. Testing for somatic DICER1 mutations was also conducted on one case with a known germ-line DICER1 mutation. From the eighteen PinBs, we identified four deleterious DICER1 mutations, three of which were germ line in origin, and one for which a germ line versus somatic origin could not be determined; in all four, the second allele was also inactivated leading to complete loss of DICER1 protein. No somatic DICER1 RNase IIIb mutations were identified. One PinB arising in a germ-line DICER1 mutation carrier was found to have LOH. This study suggests that germ-line DICER1 mutations make a clinically significant contribution to PinB, establishing DICER1 as an important susceptibility gene for PinB and demonstrates PinB to be a manifestation of a germ-line DICER1 mutation. The means by which the second allele is inactivated may differ from other DICER1-related tumours. PMID:25022261

  7. Germ-line and somatic DICER1 mutations in pineoblastoma

    PubMed Central

    de Kock, Leanne; Sabbaghian, Nelly; Druker, Harriet; Weber, Evan; Hamel, Nancy; Miller, Suzanne; Choong, Catherine S.; Gottardo, Nicholas G.; Kees, Ursula R.; Rednam, Surya P.; van Hest, Liselotte P.; Jongmans, Marjolijn C.; Jhangiani, Shalini; Lupski, James R.; Zacharin, Margaret; Bouron-Dal Soglio, Dorothée; Huang, Annie; Priest, John R.; Perry, Arie; Mueller, Sabine; Albrecht, Steffen; Malkin, David; Grundy, Richard G.

    2015-01-01

    Germ-line RB-1 mutations predispose to pineoblastoma (PinB), but other predisposing genetic factors are not well established. We recently identifed a germ-line DICER1 mutation in a child with a PinB. This was accompanied by loss of heterozygosity (LOH) of the wild-type allele within the tumour. We set out to establish the prevalence of DICER1 mutations in an opportunistically ascertained series of PinBs. Twenty-one PinB cases were studied: eighteen cases had not undergone previous testing for DICER1 mutations; three patients were known carriers of germ-line DICER1 mutations. The eighteen PinBs were sequenced by Sanger and/or Fluidigm-based next-generation sequencing to identify DICER1 mutations in blood gDNA and/or tumour gDNA. Testing for somatic DICER1 mutations was also conducted on one case with a known germ-line DICER1 mutation. From the eighteen PinBs, we identified four deleterious DICER1 mutations, three of which were germ line in origin, and one for which a germ line versus somatic origin could not be determined; in all four, the second allele was also inactivated leading to complete loss of DICER1 protein. No somatic DICER1 RNase IIIb mutations were identified. One PinB arising in a germ-line DICER1 mutation carrier was found to have LOH. This study suggests that germ-line DICER1 mutations make a clinically significant contribution to PinB, establishing DICER1 as an important susceptibility gene for PinB and demonstrates PinB to be a manifestation of a germ-line DICER1 mutation. The means by which the second allele is inactivated may differ from other DICER1-related tumours. PMID:25022261

  8. Lipase inactivation in wheat germ by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Jha, Pankaj Kumar; Kudachikar, V. B.; Kumar, Sourav

    2013-05-01

    An attempt was made to improve the shelf life of wheat germ by optimizing processing conditions involving ?-irradiation. Studies were carried out to investigate the effect of ?-irradiation (0-30 kGy doses) on the chemical composition of wheat germ with respect to variation in moisture, total ash, crude fat, free fatty acid, protein and lipase activity. The results demonstrate that shelf stability of wheat germ was achieved by inactivation of lipase at doses of ?-irradiation greater than 12 kGy.

  9. Salmonella Is a Sneaky Germ: Seven Tips for Safer Eating

    MedlinePLUS

    ... What's this? Submit Button Past Emails CDC Features Salmonella is a Sneaky Germ: Seven Tips for Safer ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Salmonella can contaminate more than poultry and eggs. It ...

  10. General Information About Childhood Central Nervous System Germ Cell Tumors

    MedlinePLUS

    ... germ cell tumors to form is near the pineal gland and in an area of the brain ... of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal ...

  11. Treatment Option Overview (Childhood Central Nervous System Germ Cell Tumors)

    MedlinePLUS

    ... germ cell tumors to form is near the pineal gland and in an area of the brain ... of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal ...

  12. The role of testicular germ cell apoptosis during equine spermatogenesis 

    E-print Network

    Heninger, Noah Leland, III

    2007-04-25

    Apoptosis in testicular germ cells has been demonstrated in many species. Features of apoptosis reported in other species were used to confirm use of the TUNEL assay in stallion testes. Eight stallions with normal testicular size and semen quality...

  13. Germs in Foodborne Illness Gaining Resistance to Antibiotics

    MedlinePLUS

    ... 9, 2015 TUESDAY, June 9, 2015 (HealthDay News) -- Antibiotic resistance in foodborne germs remains a public health threat ... for Disease Control and Prevention reported online Tuesday. "Antibiotic resistance can arise spontaneously, but the greatest contribution to ...

  14. Severe Burns May Trigger Dangerous Shifts in Gut Germs

    MedlinePLUS

    ... Gut Germs Study suggests that treating patients with probiotics might help prevent complications To use the sharing ... treating patients with live beneficial bacteria known as probiotics may help restore their microbiotic health. The findings ...

  15. Conservative management of testicular germ-cell tumors

    Microsoft Academic Search

    Tim Oliver

    2007-01-01

    Cure rates of germ-cell cancer have been greater than 95% for the last decade; therefore, over the past few years there has been a greater focus on 'conservative' approaches to treatment. The increased incidence of late non-germ-cell cancers in the era of radiotherapy and the incidence of subclinical testicular deficiency and metabolic syndrome in cured patients have accelerated this trend.

  16. Equipment for germ-free caesarean section and baby care

    Microsoft Academic Search

    J. Trávní?ek; L. Mandel; P. Kasal; J. Král; V. Mydlil

    1977-01-01

    A germ-free isolator system was designed and constructed, It permits a sterile caesarean section and rearing of an infant\\u000a under germ-free conditions. The system includes a plastic surgical and rearing isolator and two supply isolators; one of the\\u000a supply isolators served as a transport mobile unit for the transfer of the newborn from the operation room to the neonatal\\u000a intensive

  17. 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 biomass in the Black Sea during anomalously warm years, as seen in satellite observations.

  18. 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.

  19. Expression of BLIMP1\\/PRMT5 and concurrent histone H2A\\/H4 arginine 3 dimethylation in fetal germ cells, CIS\\/IGCNU and germ cell tumors

    Microsoft Academic Search

    Dawid Eckert; Katharina Biermann; Daniel Nettersheim; Ad JM Gillis; Klaus Steger; Hans-Martin Jäck; Annette M Müller; Leendert HJ Looijenga; Hubert Schorle

    2008-01-01

    BACKGROUND: Most testicular germ cell tumors arise from intratubular germ cell neoplasia unclassified (IGCNU, also referred to as carcinoma in situ), which is thought to originate from a transformed primordial germ cell (PGC)\\/gonocyte, the fetal germ cell. Analyses of the molecular profile of IGCNU and seminoma show similarities to the expression profile of fetal germ cells\\/gonocytes. In murine PGCs, expression

  20. Germ cell development in the human and marmoset fetal testis and the origins of testicular germ cell tumours 

    E-print Network

    Mitchell, Roderick T.

    2010-01-01

    Normal germ cell development in the human testis is crucial for subsequent fertility and reproductive health. Disruption of testis development in fetal life can result in deleterious health consequences such as testicular dysgenesis syndrome (TDS...

  1. Nutritive phagocyte incubation chambers provide a structural and nutritive microenvironment for germ cells of Strongylocentrotus droebachiensis, the green sea urchin.

    PubMed

    Walker, Charles W; Harrington, Laura M; Lesser, Michael P; Fagerberg, Wayne R

    2005-08-01

    Here we characterize the germinal epithelia of both sexes of Strongylocentrotus droebachiensis, the green sea urchin, throughout its annual gametogenic cycle, using light and electron microscopy and cytochemistry. In both sexes, germinal epithelia include two interacting cellular populations: nutritive phagocytes (NPs) and germ cells. After spring spawning, NPs accumulate nutrients; amitotic oogonia and often mitotic spermatogonia occur in clusters beneath NPs; and subsequent gametogenic stages are residual or absent. During the summer, NP nutrients are mobilized for use in vitellogenesis by residual primary oocytes or to support limited spermatogenesis. In addition, some residual primary oocytes may degenerate and be phagocytized by NPs. Significant nutrient mobilization from NPs and substantial gonial cell mitoses (indicative of new gametogenesis) occur in the fall. In both sexes, all of these changes are facilitated by NPs that form basal incubation chambers near the gonadal wall and within which germ cells are surrounded by nutrients released from the NPs. In females, germ cells at several stages of gametogenesis may be housed in separate chambers in the same NP. Primary oocytes also carry out jelly coat formation, meiosis, and cortical granule translocation within NP incubation chambers. In males, many NPs cooperate to provide large continuous chambers that contain spermatogenic cells at diverse stages. In both sexes these chambers persist throughout the year and isolate gametogenesis from the gonadal lumen. NPs become slender and shorten as their nutrients are depleted. Ova or spermatozoa are stored in the gonadal lumen. Post-spawning, NPs phagocytize differentiated germ cells while simultaneously enclosing intact gonial and residual gametogenic cells in basal chambers near the gonadal wall. In light of our observations, we suggest investigating proteins that may be important in the structural, phagocytic, and nutritive functions of NPs and for which corresponding genes have already been identified in the genome of S. purpuratus, the closely related purple sea urchin. PMID:16110092

  2. Association of metallothionein expression and clinical response to cisplatin based chemotherapy in testicular germ cell tumors

    PubMed Central

    Yorukoglu, Kutsal; Ozkara, Esra; Kirkali, Ziya

    2015-01-01

    Introduction The protective roles of metallothioneins (MT) against metal toxicity suggest that MT may have a functional role in cisplatin resistance. The aim of this study was to investigate the expression of MT in specimens of germ cell tumors and compare it with clinical sensitivity to cisplatin based chemotherapy. Material and methods Tissue blocks of primary GCT specimens obtained from 39 patients were examined immunohistochemically for MT expression. Staining intensity was evaluated according to the percentage of MT positive cells and graded as [-], [+] and [++]. The staining characteristics were compared with the clinical response to chemotherapy. Results Of the 39 tumors, 3 evidenced no MT expression while 26 and 10 specimens showed [+] and [++] staining, respectively. Although seminomas tend to stain weaker than non-seminomas, the difference of staining between them was not significant (p = 0.19). Of the 39 patients, 23 underwent cisplatin based chemotherapy. Of those, 6 progressed and 17 achieved complete remission. Of the non-responders, 5 showed [+] and 1 showed [++] staining. Six of the responders showed [+], 10 had [++] and 1 showed no staining. No association was found between MT staining and chemo-sensitivity (p = 0.53). Conclusions MT expression in primary germ cell tumors did not differ between responding and non-responding patients and therefore may not be useful in predicting response to chemotherapy. PMID:25914837

  3. A bilateral primary yolk sac tumor of the lung associated with chromosome 3 polysomy: understanding the Oct 3/4 and Sox 2 interaction.

    PubMed

    Arora, Shitij; Patel, Harish; Mir, Pervez; Mishra, Sneha; Kalra, Amita; Sawhney, Harinder; Duffoo, Frantz; Macera, Mike; Abdu, Afaf; Thelmo, William

    2013-01-01

    Extragonadal germ cell tumors (EGCTs) in the lung are extremely rare and their pathogenesis is poorly understood. We report a case in a 48-year-old female which was very aggressive and stained positive for primoridial germ cell markers. Interestingly, there was chromosome 3 polysomy noted. To our knowledge this is the first chromosomal aberration noted in a primary germ cell tumor of the lung. PMID:23114647

  4. Folding and Homodimerization of Wheat Germ Agglutinin

    PubMed Central

    Portillo-Téllez, María del Carmen; Bello, Martiniano; Salcedo, Guillermo; Gutiérrez, Gabriel; Gómez-Vidales, Virginia; García-Hernández, Enrique

    2011-01-01

    Wheat germ agglutinin (WGA) is emblematic of proteins that specialize in the recognition of carbohydrates. It was the first lectin reported to have a capacity for discriminating between normal and malignant cells. Since then, it has become a preferred model for basic research and is frequently considered in the development of biomedical and biotechnological applications. However, the molecular basis for the structural stability of this homodimeric lectin remains largely unknown, a situation that limits the rational manipulation and modification of its function. In this work we performed a thermodynamic characterization of WGA folding and self-association processes as a function of pH and temperature by using differential scanning and isothermal dilution calorimetry. WGA is monomeric at pH 2, and one of its four hevein-like domains is unfolded at room temperature. Under such conditions, the agglutinin exhibits a fully reversible thermal unfolding that consists of three two-state transitions. At higher pH values, the protein forms weak, nonobligate dimers. This behavior contrasts with that observed for the other plant lectins studied thus far, which form strong, obligate oligomers, indicating a distinctly different molecular basis for WGA function. For dimer formation, the four domains must be properly folded. Nevertheless, depending on the solution conditions, self-association may be coupled with folding of the labile domain. Therefore, dimerization may proceed as a rigid-body-like association or a folding-by-binding event. This hybrid behavior is not seen in other plant lectins. The emerging molecular picture for the WGA assembly highlights the need for a reexamination of existing ligand-binding data in the literature. PMID:21943423

  5. 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

  6. 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

  7. Very few substitutions in a germ line antibody are required to initiate significant domain exchange.

    PubMed

    Huber, Michael; Le, Khoa M; Doores, Katie J; Fulton, Zara; Stanfield, Robyn L; Wilson, Ian A; Burton, Dennis R

    2010-10-01

    2G12 is a broadly neutralizing anti-HIV-1 monoclonal human IgG1 antibody reactive with a high-mannose glycan cluster on the surface of glycoprotein gp120. A key feature of this very highly mutated antibody is domain exchange of the heavy-chain variable region (V(H)) with the V(H) of the adjacent Fab of the same immunoglobulin, which assembles a multivalent binding interface composed of two primary binding sites in close proximity. A non-germ line-encoded proline in the elbow between V(H) and C(H)1 and an extensive network of hydrophobic interactions in the V(H)/V(H)' interface have been proposed to be crucial for domain exchange. To investigate the origins of domain exchange, a germ line version of 2G12 that behaves as a conventional antibody was engineered. Substitution of 5 to 7 residues for those of the wild type produced a significant fraction of domain-exchanged molecules, with no evidence of equilibrium between domain-exchanged and conventional forms. Two substitutions not previously implicated, A(H14) and E(H75), are the most crucial for domain exchange, together with I(H19) at the V(H)/V(H)' interface and P(H113) in the elbow region. Structural modeling gave clues as to why these residues are essential for domain exchange. The demonstration that domain exchange can be initiated by a small number of substitutions in a germ line antibody suggests that the evolution of a domain-exchanged antibody response in vivo may be more readily achieved than considered to date. PMID:20702640

  8. MicroRNA-34c Enhances Murine Male Germ Cell Apoptosis through Targeting ATF1

    PubMed Central

    Liang, Xiaoxuan; Zhou, Doudou; Wei, Chao; Luo, Haoshu; Liu, Jiali; Fu, Rui; Cui, Sheng

    2012-01-01

    Background MicroRNAs (miRNAs) play vital regulatory roles in many cellular processes. The expression of miRNA (miR)-34c is highly enriched in adult mouse testis, but its roles and underlying mechanisms of action are not well understood. Methodology/Principal Findings In the present study, we show that miR-34c is detected in mouse pachytene spermatocytes and continues to be highly expressed in spermatids. To explore the specific functions of miR-34c, we have established an in vivo model by transfecting miR-34c inhibitors into primary spermatocytes to study the loss-of-function of miR-34c. The results show that silencing of miR-34c significantly increases the Bcl-2/Bax ratio and prevents germ cell from apoptosis induced by deprivation of testosterone. Moreover, ectopic expression of the miR-34c in GC-2 cell trigger the cell apoptosis with a decreased Bcl-2/Bax ratio and miR-34c inhibition lead to a low spontaneous apoptotic ratio and an increased Bcl-2/Bax ratio. Furthermore, ectopic expression of miR-34c reduces ATF1 protein expression without affecting ATF1 mRNA level via directly binding to ATF1's 3?UTR, indicating that ATF1 is one of miR-34c's target genes. Meanwhile, the knockdown of ATF1 significantly decreases the Bcl-2/Bax ratio and triggers GC-2 cell apoptosis. Inhibition of miR-34c does not decrease the GC-2 cell apoptosis ratio in ATF1 knockdown cells. Conclusions/Significance Our study shows for the first time that miR-34c functions, at least partially, by targeting the ATF1 gene in germ cell apoptosis, providing a novel mechanism with involvement of miRNA in the regulation of germ cell apoptosis. PMID:22479460

  9. 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

  10. Reproduction of wild birds via interspecies germ cell transplantation.

    PubMed

    Kang, Seok Jin; Choi, Jin Won; Kim, Sun Young; Park, Kyung Je; Kim, Tae Min; Lee, Young Mok; Kim, Heebal; Lim, Jeong Mook; Han, Jae Yong

    2008-11-01

    The present study was conducted to apply an interspecies germ cell transfer technique to wild bird reproduction. Pheasant (Phasianus colchicus) primordial germ cells (PGCs) retrieved from the gonads of 7-day-old embryos were transferred to the bloodstream of 2.5-day-old chicken (Gallus gallus) embryos. Pheasant-to-chicken germline chimeras hatched from the recipient embryos, and 10 pheasants were derived from testcross reproduction of the male chimeras with female pheasants. Gonadal migration of the transferred PGCs, their involvement in spermatogenesis, and production of chimeric semen were confirmed. The phenotype of pheasant progenies derived from the interspecies transfer was identical to that of wild pheasants. The average efficiency of reproduction estimated from the percentage of pheasants to total progenies was 17.5%. In conclusion, interspecies germ cell transfer into a developing embryo can be used for wild bird reproduction, and this reproductive technology may be applicable in conserving endangered bird species. PMID:18685127

  11. The role of retinoic acid in germ cell development in embryonic mouse gonads

    E-print Network

    Koubová, Jana C

    2007-01-01

    Germ cells are the only cell type to undergo meiosis, a specialized cell division process necessary for the formation of haploid gametes. Timing of this process is sex-specific. Ovarian germ cells initiate meiosis during ...

  12. Enhanced Genetic Integrity in Mouse Germ Cells1

    PubMed Central

    Murphey, Patricia; McLean, Derek J.; McMahan, C. Alex; Walter, Christi A.; McCarrey, John R.

    2012-01-01

    ABSTRACT Genetically based diseases constitute a major human health burden, and de novo germline mutations represent a source of heritable genetic alterations that can cause such disorders in offspring. The availability of transgenic rodent systems with recoverable, mutation reporter genes has been used to assess the occurrence of spontaneous point mutations in germline cells. Previous studies using the lacI mutation reporter transgenic mouse system showed that the frequency of spontaneous mutations is significantly lower in advanced male germ cells than in somatic cell types from the same individuals. Here we used this same mutation reporter transgene system to show that female germ cells also display a mutation frequency that is lower than that in corresponding somatic cells and similar to that seen in male germ cells, indicating this is a common feature of germ cells in both sexes. In addition, we showed that statistically significant differences in mutation frequencies are evident between germ cells and somatic cells in both sexes as early as mid-fetal stages in the mouse. Finally, a comparison of the mutation frequency in a general population of early type A spermatogonia with that in a population enriched for Thy-1-positive spermatogonia suggests there is heterogeneity among the early spermatogonial population such that a subset of these cells are predestined to form true spermatogonial stem cells. Taken together, these results support the disposable soma theory, which posits that genetic integrity is normally maintained more stringently in the germ line than in the soma and suggests that this is achieved by minimizing the initial occurrence of mutations in early germline cells and their subsequent gametogenic progeny relative to that in somatic cells. PMID:23153565

  13. The microRNA pathway controls germ cell proliferation and differentiation in C. elegans

    PubMed Central

    Bukhari, Syed Irfan Ahmad; Vasquez-Rifo, Alejandro; Gagné, Dominic; Paquet, Eric R; Zetka, Monique; Robert, Claude; Masson, Jean-Yves; Simard, Martin J

    2012-01-01

    The discovery of the miRNA pathway revealed a new layer of molecular control of biological processes. To uncover new functions of this gene regulatory pathway, we undertook the characterization of the two miRNA-specific Argonaute proteins in Caenorhabditis elegans, ALG-1 and ALG-2. We first observed that the loss-of-function of alg-1 and alg-2 genes resulted in reduced progeny number. An extensive analysis of the germline of these mutants revealed a reduced mitotic region, indicating fewer proliferating germ cells. We also observed an early entry into meiosis in alg-1 and alg-2 mutant animals. We detected ALG-1 and ALG-2 protein expressions in the distal tip cell (DTC), a specialized cell located at the tip of both C. elegans gonadal arms that regulates mitosis-meiosis transition. Re-establishing the expression of alg-1 specifically in the DTC of mutant animals partially rescued the observed germline defects. Further analyses also support the implication of the miRNA pathway in gametogenesis. Interestingly, we observed that disruption of five miRNAs expressed in the DTC led to similar phenotypes. Finally, gene expression analysis of alg-1 mutant gonads suggests that the miRNA pathway is involved in the regulation of different pathways important for germline proliferation and differentiation. Collectively, our data indicate that the miRNA pathway plays a crucial role in the control of germ cell biogenesis in C. elegans. PMID:22370633

  14. Chiral discotic columnar germs of nucleosome core particles.

    PubMed Central

    Livolant, F; Leforestier, A

    2000-01-01

    In concentrated solution and in the presence of high concentrations of monovalent cations, nucleosome core particles order into a discotic columnar mesophase. This phase is limited to finite-sized hexagonal germs that further divide into six coiled branches, following an iterative process. We show how the structure of the germs comes from the competition between hexagonal packing and chirality with a combination of dendritic facetting and double-twist configurations. Geometrical considerations lead us to suspect that the chirality of the eukaryotic chromosomes may originate from the same competition. PMID:10777768

  15. 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

  16. The meiosis inducing interaction between germ cells and rete cells in the fetal mouse gonad

    E-print Network

    Paris-Sud XI, Université de

    The meiosis inducing interaction between germ cells and rete cells in the fetal mouse gonad Anne., Denmark. Introduction. In the mammalian gonad the onset of meiosis of the female germ cells occurs much earlier in life than meiosis of the male germ cells. In the ovary we know that both the differentiation

  17. USING MICROWAVE HEATING TO DETERMINE OPTIMAL CORN GERM OIL YIELD WITH A BENCH-SCALE PRESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods have been proposed recently to separate germ from corn prior to fermentation to improve dry grind ethanol process economic return. Oil would be extracted from the germ and sold as a separate product. It is not clear that available methods to extract oil from this germ are economically pra...

  18. Transplantation of Germ Line Stem Cells for the Study and Manipulation of Spermatogenesis

    Microsoft Academic Search

    I. Dobrinski

    Transplantation of male germ line stem cells from a fertile donor to the testis of an infertile recipient restores donor-derived spermatogenesis in the recipient testis and the resulting sperm pass the donor genotype to the offspring of the recipient. Germ cell transplantation has been an invaluable tool to elucidate the biology of male germ line stem cells and their niche

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

    Microsoft Academic Search

    Holger Knaut; Christian Werz; Robert Geisler; Christiane Nüsslein-Volhard

    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,

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

    PubMed Central

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

    2003-01-01

    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

  1. Information Dynamics Across Sub-networks: Germs, Genes, and Memes Patrick Grim,ad

    E-print Network

    Grim, Patrick

    Information Dynamics Across Sub-networks: Germs, Genes, and Memes Patrick Grim,ad Daniel J. Singer, University of Michigan, Ann Arbor, MI 48109 Abstract Beyond belief change and meme adoption, both genetics: the different network dynamics of germs, genes, and memes. Germs and memes, it turns out, exhibit a very

  2. Germ cell transplantation: a review and progress report on ICSI from spermatozoa generated in xenogeneic testes

    Microsoft Academic Search

    N. Sofikitis; A. Kaponis; Y. Mio; D. Makredimas; D. Giannakis; Y. Yamamoto; N. Kanakas; H. Kawamura; J. Georgiou; M. Schrader; E. Lolis; X. Giannakopoulos; D. Loutradis; V. Tarlatzis; I. Miyagawa

    2003-01-01

    Results from the transplantation of donor male germ cells into xenogeneic recipient seminiferous tubules indicate that donor spermatogonia are capable of differentiating to form spermatozoa morphologically characteristic of the donor species. Germ cell transplantation procedures combined with developments in freezing, culturing or enrich- ing germ cell populations have applications of paramount importance in medicine, basic sciences and animal repro- duction.

  3. RESEARCH Open Access Identification of a putative germ plasm in the

    E-print Network

    Extavour, Cassandra

    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 animals that have been examined, germ cells are specified by inheritance of a specialized cyto- plasm

  4. Evolution of predetermined germ cells in vertebrate embryos: implications for macroevolution

    Microsoft Academic Search

    Andrew D. Johnson; Matthew Drum; Rosemary F. Bachvarova; Thomas Masi; Mary E. White; Brian I. Crotherd

    2003-01-01

    SUMMARY The germ line is established in animal embryos with the formation of primordial germ cells (PGCs), which give rise to gametes. Therefore, the need to form PGCs can act as a developmental constraint by inhibiting the evolution of embryonic patterning mechanisms that compromise their development. Conversely, events that stabilize the PGCs may liberate these constraints. Two modes of germ

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

    ClinicalTrials.gov

    2015-05-11

    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

  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. Production of maternal-zygotic mutant zebrafish by germ-line replacement

    Microsoft Academic Search

    Brian Ciruna; Gilbert Weidinger; Holger Knaut; Bernard Thisse; Christine Thisse; Erez Raz; Alexander F. Schier

    2002-01-01

    We report a generally applicable strategy for transferring zygotic lethal mutations through the zebrafish germ line. By using a morpholino oligonucleotide that blocks primordial germ cell (PGC) development, we generate embryos devoid of endogenous PGCs to serve as hosts for the transplantation of germ cells derived from homozygous mutant donors. Successful transfers are identified by the localization of specifically labeled

  8. GAGE Cancer-Germline Antigens Are Recruited to the Nuclear Envelope by Germ Cell-Less (GCL)

    PubMed Central

    Gjerstorff, Morten F.; Rösner, Heike I.; Pedersen, Christina B.; Greve, Katrine B. V.; Schmidt, Steffen; Wilson, Katherine L.; Mollenhauer, Jan; Besir, Hüseyin; Møllegaard, Niels Erik; Ditzel, Henrik J.

    2012-01-01

    GAGE proteins are highly similar, primate-specific molecules with unique primary structure and undefined cellular roles. They are restricted to cells of the germ line in adult healthy individuals, but are broadly expressed in a wide range of cancers. In a yeast two-hybrid screen we identified the metazoan transcriptional regulator, Germ cell-less (GCL), as an interaction partner of GAGE12I. GCL directly binds LEM-domain proteins (LAP2?, emerin, MAN1) at the nuclear envelope, and we found that GAGE proteins were recruited to the nuclear envelope inner membrane by GCL. Based on yeast two-hybrid analysis and pull-down experiments of GCL polypeptides, GCL residues 209–320 (which includes the BACK domain) were deduced sufficient for association with GAGE proteins. GAGE mRNAs and GCL mRNA were demonstrated in human testis and most types of cancers, and at the protein level GAGE members and GCL were co-expressed in cancer cell lines. Structural studies of GAGE proteins revealed no distinct secondary or tertiary structure, suggesting they are intrinsically disordered. Interestingly GAGE proteins formed stable complexes with dsDNA in vitro at physiological concentrations, and GAGE12I bound several different dsDNA fragments, suggesting sequence-nonspecific binding. Dual association of GAGE family members with GCL at the nuclear envelope inner membrane in cells, and with dsDNA in vitro, implicate GAGE proteins in chromatin regulation in germ cells and cancer cells. PMID:23029259

  9. Coexistence of intracranial germ cell tumor and craniopharyngioma in an adolescent: case report and review of the literature

    PubMed Central

    Tsoukalas, Nikolaos; Tolia, Maria; Kostakis, Ioannis D; Pistamaltzian, Nikolaos; Tryfonopoulos, Dimitrios; Lypas, Georgios; Koumakis, Georgios; Barbounis, Vasileios; Goutas, Nikolaos; Efremidis, Anna

    2013-01-01

    Purpose: We present the case of a patient treated for intracranial germ cell tumor in which elements of craniopharyngioma were found in the residual tumor mass. Findings: A 17 year old patient presented with a history of secondary amenorrhea. She deteriorated with headache and left eyelid drop, paresis of the abducent nerve and convergent strabismus (Parinaud syndrome). ?-HCG was 722mIU/ml and pregnancy was excluded. AFP was 6322 ng/ml. Brain CT scan showed a large endosellar tumor to the hypersellar region. There was left papillary atrophy. MRI confirmed a tumor to dorsum sellae. Primary germ cell intracranial tumor was diagnosed. Severe clinically evident pituitary failure developed with signs of increased intracranial pressure and brain edema as well as diabetes insipidus, while AFP increased to 15786,3ng/ml. Urgent treatment with combination chemotherapy including cisplatin etoposide and bleomycin (?EB) was administered for 4 courses. As a result her clinical condition improved and tumor markers dropped but nevertheless did not become normal. In addition CT scans revealed a remaining endocranial mass and therefore the patient was subjected to high-dose chemotherapy followed by autologous stemcell rescue which resulted in complete clinical and biochemical remission. Due to the persisting mass in the area, it was delivered radiotherapy. Conclusions: The above case is extremely rare in worldwide literature. Dysgerminoma may coexist with craniopharyngioma which in fact may be part of a germ cell tumor in the context of dysembryogenesis and benign “teratoma”. PMID:23573353

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

    PubMed

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

    2014-04-01

    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

  11. 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

  12. Random Germs and Stochastic Watershed for Unsupervised Multispectral Image Segmentation

    E-print Network

    Angulo,Jesús

    Random Germs and Stochastic Watershed for Unsupervised Multispectral Image Segmentation Guillaume.noyel,jesus.angulo,dominique.jeulin}@ensmp.fr Abstract. This paper extends the use of stochastic watershed, recently introduced by Angulo and Jeulin [1 are then segmented by a volume-based watershed algorithm to define the R largest regions. The various gradients

  13. Immunocytological Differentiation of Hepatocellular Carcinoma versus Extragonadal Germ Cell Tumor

    Microsoft Academic Search

    J. Hastka; M. H. Bohrer; G. Hartung; C. S. Verbeke

    1991-01-01

    Summary Extragonadal germ cell tumor versus hepatocellular carcinoma must be distinguished in case of diffuse metastatic liver disease and highly elevated alpha-fetoprotein serum levels. The differential diagnosis is difficult, and conventional histological staining methods usually yield no results. However, liver puncture and immuncytology are new and reliable means for differentiation. The antibody HE A 125 reacts with all epithelial tumors

  14. 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...

  15. A Method for Cryopreserving Chicken Primordial Germ Cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study established a method for preserving chicken primordial germ cells (PGCs) that enables long-term storage in liquid nitrogen. Gonads were harvested from stage 27 chick embryos and pooled in groups of 5 (5E), 10 (10E), or 20 (20E) embryos contributing gonads to the cell suspension. The gona...

  16. Forget the Parents: Epigenetic Reprogramming in Human Germ Cells.

    PubMed

    von Meyenn, Ferdinand; Reik, Wolf

    2015-06-01

    Epigenetic reprogramming in the germline resets genomic potential and erases epigenetic memory. Three studies by Gkountela et al., Guo et al., and Tang et al. analyze the transcriptional and epigenetic landscape of human primordial germ cells, revealing a unique transcriptional network and progressive and conserved global erasure of DNA methylation. PMID:26046435

  17. Germline cysts: a conserved phase of germ cell development?

    Microsoft Academic Search

    Melissa E Pepling; Margaret de Cuevas; Allan C Spradling

    1999-01-01

    Germ cells in many vertebrate and invertebrate species initiate gametogenesis by forming groups of interconnected cells known as germline cysts. Recent studies using Xenopus, mouse and Drosophila are beginning to uncover the cellular and molecular mechanisms that control germline cyst formation and, in conjunction with morphological evidence, suggest that the process is highly conserved during evolution. This article discusses these

  18. Female mouse germ cells form synchronously dividing cysts

    Microsoft Academic Search

    Melissa E. Pepling; Allan C. Spradling

    1998-01-01

    Oocytes from many invertebrates initiate development within distinctive cysts of interconnected cells, which are formed through synchronous divisions of a progenitor cell. Recently, processes underlying cyst formation have been extensively characterized at the molecular level in Drosophila. Defects in this process cause sterility in female flies. Early female mouse germ cells are organized as cell clusters as well, but it

  19. Edinburgh Research Explorer Germ cell sex determination in mammals

    E-print Network

    Millar, Andrew J.

    of meiosis-inducing and meiosis-preventing substances in the developing gonad, and more recent studies aimed of these factors on germ cell development may be indirect consequences of impairing sexual differentiation chromosomes. A number of genes have been implicated in translating the sex chromosome constitutio

  20. 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...

  1. Crucial genes and pathways in chicken germ stem cell differentiation.

    PubMed

    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

    2015-05-22

    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-?, 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

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

    E-print Network

    Shupe, Matthew

    sink is sedimentation. Large-eddy simu- lations with size-resolved microphysics are initializedA FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate, in final form 2 August 2011) ABSTRACT Observations of long-lived mixed-phase Arctic boundary layer clouds

  3. 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

  4. Selective accumulation of germ-line associated gene products in early development of the sea star and distinct differences from germ-line development in the sea urchin

    PubMed Central

    Fresques, Tara; Zazueta-Novoa, Vanesa; Reich, Adrian; Wessel, Gary M.

    2014-01-01

    Background Echinodermata is a diverse Phylum, a sister group to chordates, and contains diverse organisms that may be useful to understand varied mechanisms of germ-line specification. Results We tested 23 genes in development of the sea star Patiria miniata that fall into five categories: 1) Conserved germ-line factors; 2) Genes involved in the inductive mechanism of germ-line specification; 3) Germ-line associated genes; 4) Molecules involved in left-right asymmetry; and 5) Genes involved in regulation and maintenance of the genome during early embryogenesis. Overall, our results support the contention that the posterior enterocoel is a source of the germ line in the sea star P. miniata. Conclusion The germ line in this organism appears to be specified late in embryogenesis, and in a pattern more consistent with inductive interactions amongst cells. This is distinct from the mechanism seen in sea urchins, a close relative of the sea star clad. We propose that P. miniata may serve as a valuable model to study inductive mechanisms of germ-cell specification and when compared to germ-line formation in the sea urchin S. purpuratus may reveal developmental transitions that occur in the evolution of inherited and inductive mechanisms of germ-line specification. PMID:24038550

  5. Clinical outcomes of patients with nonseminomatous germ cell tumours and negative postchemotherapy positron emission tomography.

    PubMed

    Buchler, Tomas; Simonova, Katerina; Fencl, Pavel; Jarkovsky, Jiri; Abrahamova, Jitka

    2012-07-01

    Univariate and multivariate analyses were carried out to identify factors associated with the failure of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) to correctly predict relapse-free survival in patients with nonseminomatous germ cell tumours. Ninety-three patients with negative postchemotherapy FDG-PET scan were analyzed in the retrospective study. The FDG-PET result was validated by long-term follow-up and, in some patients, by resection of the residual tumour mass. The negative predictive value of FDG-PET was 81.7%. Higher tumour marker levels and nodal stage at diagnosis, presence of residual mass, and teratoma or teratocarcinoma in the primary histology were associated with FDG-PET failure. PMID:22506657

  6. Wheat germ lectin-Sepharose affinity adsorption assay for the soluble glucagon receptor

    SciTech Connect

    Iyengar, R.; Herberg, J.T.

    1985-01-01

    An assay was developed based on the observation that many hormone receptors are glycoproteins. To test if the glucagon receptor is a glycoprotein, the receptor was used that had (/sup 125/I-Tyr/sup 10/)monoiodoglucagon covalently attached. The covalently labelled receptor was solubilized and exposed to wheat germ lectin-Sepharose in the presence and absence of various sugars. The sugar specificity for the adsorption of the glucagon receptor indicated that the receptor is a glycoprotein. The primary structure of glucagon is known and has been shown that it has no sugars attached to it. Therefore, the different in covalently attached sugars between the hormone and the receptor was used to develop an assay for the solubilized receptor. The hormone-receptor complex was specifically adsorbed onto the lectin-Sepharose while the free hormone remained in solution.

  7. Prmt5 is required for germ cell survival during spermatogenesis in mice.

    PubMed

    Wang, Yanbo; Zhu, Tianxiang; Li, Qiuling; Liu, Chunyi; Han, Feng; Chen, Min; Zhang, Lianjun; Cui, Xiuhong; Qin, Yan; Bao, Shilai; Gao, Fei

    2015-01-01

    During germ cell development, epigenetic modifications undergo extensive remodeling. Abnormal epigenetic modifications usually result in germ cell loss and reproductive defect. Prmt5 (Protein arginine methyltransferase 5) encodes a protein arginine methyltransferase which has been demonstrated to play important roles in germ cell development during embryonic stages. In the present study, we found that Prmt5 was also abundantly expressed in male germ cells after birth. Inactivation of this gene by crossing with Stra8-Cre transgenic mice resulted in germ cell loss during spermatogenesis. Further study revealed that the germ cell development was grossly normal before P10. However, most of the germ cells in Prmt5(?/f); Stra8-Cre mice were blocked at meiotic stage. The expression of meiosis associated genes was reduced in Prmt5(?/f); Stra8-Cre testes compared to control testes at P10. ?H2AX was detected in sex body of control germ cells at P12, whereas multiple foci were observed in Prmt5-deficient germ cells. Further study revealed that H4R3me2s was virtually absent in germ cells after Prmt5 inactivation. The results of this study indicate that Prmt5 also plays important roles in germ cell development during spermatogenesis. PMID:26072710

  8. Prmt5 is required for germ cell survival during spermatogenesis in mice

    PubMed Central

    Wang, Yanbo; Zhu, Tianxiang; Li, Qiuling; Liu, Chunyi; Han, Feng; Chen, Min; Zhang, Lianjun; Cui, Xiuhong; Qin, Yan; Bao, Shilai; Gao, Fei

    2015-01-01

    During germ cell development, epigenetic modifications undergo extensive remodeling. Abnormal epigenetic modifications usually result in germ cell loss and reproductive defect. Prmt5 (Protein arginine methyltransferase 5) encodes a protein arginine methyltransferase which has been demonstrated to play important roles in germ cell development during embryonic stages. In the present study, we found that Prmt5 was also abundantly expressed in male germ cells after birth. Inactivation of this gene by crossing with Stra8-Cre transgenic mice resulted in germ cell loss during spermatogenesis. Further study revealed that the germ cell development was grossly normal before P10. However, most of the germ cells in Prmt5?/f; Stra8-Cre mice were blocked at meiotic stage. The expression of meiosis associated genes was reduced in Prmt5?/f; Stra8-Cre testes compared to control testes at P10. ?H2AX was detected in sex body of control germ cells at P12, whereas multiple foci were observed in Prmt5-deficient germ cells. Further study revealed that H4R3me2s was virtually absent in germ cells after Prmt5 inactivation. The results of this study indicate that Prmt5 also plays important roles in germ cell development during spermatogenesis. PMID:26072710

  9. 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

    2014-11-20

    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. PMID:25486044

  10. Germ plasm in Eleutherodactylus coqui, a direct developing frog with large eggs

    PubMed Central

    2011-01-01

    Background RNAs for embryo patterning and for germ cell specification are localized to the vegetal cortex of the oocyte of Xenopus laevis. In oocytes of the direct developing frog Eleutherodactylus coqui, orthologous RNAs for patterning are not localized, raising the question as to whether RNAs and other components of germ plasm are localized in this species. Methods To identify germ plasm, E. coqui embryos were stained with DiOC6(3) or examined by in situ hybridization for dazl and DEADSouth RNAs. The cDNAs for the E. coqui orthologues were cloned by RT-PCR using degenerate primers. To examine activity of the E. coqui orthologues, RNAs, made from constructs of their 3'UTRs with mCherry, were injected into X. laevis embryos. Results Both DiOC6(3) and dazl and DEADSouth in situs identified many small islands at the vegetal surface of cleaving E. coqui embryos, indicative of germ plasm. Dazl was also expressed in primordial germ cells in the genital ridge. The 3'UTRs of E. coqui dazl and DEADSouth directed primordial germ cell specific protein synthesis in X. laevis. Conclusions E. coqui utilizes germ plasm with RNAs localized to the vegetal cortex to specify primordial germ cells. The large number of germ plasm islands suggests that an increase in the amount of germ plasm was important in the evolution of the large E. coqui egg. PMID:21978790

  11. 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. PMID:25364281

  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. Reprogramming Male Germ Cells to Pluripotent Stem Cells

    Microsoft Academic Search

    Parisa Mardanpour; Kaomei Guan; Tamara Glaeser; Jae Ho Lee; Jessica Nolte; Gerald Wulf; Gerd Hasenfuss; Wolfgang Engel; Oliver Brüstle; Karim Nayernia

    \\u000a Reprogramming of a differentiated cell into a cell capable of giving rise to many different cell types, a pluripotent cell,\\u000a which in turn could repopulate or repair nonfunctional or damaged tissue, would present beneficial applications in regenerative\\u000a medicine. It was shown by different groups that germ cells can be reprogrammed to pluripotent stem cells in all diploid stages\\u000a of development.

  14. CONSERVATION OF GERM PLASM FROM BISON INFECTED WITH BRUCELLA ABORTUS

    Microsoft Academic Search

    C. D. Robison; D. S. Davis; J. W. Templeton; M. Westhusin; W. B. Foxworth; M. J. Gilsdorf; L. G. Adams

    ABsTRA(;T: Reproductive procedures for cattle were adapted to American bison (Bison bison) to evaluate the potential preservation of germ plasm from bison infected with Brucella abortus withotut transmission of the pathogen to the recipient or offspring. Two of four experimentally inoculated bison bulls excreted B. abortus in the semen. Four healthy calves were produced from non-infected, un-vaccinated bison cows by

  15. Age-related biological features of germ cell tumours

    E-print Network

    Collinson, Kate; Murray, Matthew J.; Orsi, Nicolas M.; Cummings, Michele; Shipley, Janet; Joffe, Jonathan K.; Coleman, Nicholas; Stark, Daniel

    2013-12-05

    1 Age-related biological features of germ cell tumours Kate Collinson1, Matthew J. Murray2, Nicolas M. Orsi3, Michele Cummings3, Janet Shipley4, Jonathan K. Joffe5, Nicholas Coleman2, Daniel Stark6 Author details 1. Department... Studies and Pathology, Wellcome Trust Brenner Building, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK 4. Divisions of Molecular Pathology and Cancer Therapeutics, The Institute of Cancer Research, Surrey, UK 5. Macmillan Consultant...

  16. Histogenetic Analysis of Ovarian Germ Cell Tumors by DNA Fingerprinting

    Microsoft Academic Search

    Masaki Inoue; Masami Fujita; Chihiro Azuma; Fumitaka Saji; Osamu Tanizawa

    1992-01-01

    The histogenesis of ovarian germ cell tumors (11 mature teratomas, three malignant transformations of mature teratomas, two immature teratomas, and four dysgerminomas) was investigated genetically using minisatellite DNA probes 33.15 and 33.6 for person-specific restriction fragment length polymorphism (DNA fingerprint) analysis. The DNA fingerprints of six ovarian teratomas were identical with those of mono- nuclear cells from each host, while

  17. Wheat germ phosphoglycerate mutase: evidence for a metalloenzyme.

    PubMed

    Smith, G C; McWilliams, A D; Hass, L F

    1986-04-14

    Wheat germ phosphoglycerate mutase, exposed to 3.4 M guanidinium chloride at 22 degrees C and pH 7.8, slowly undergoes time-dependent inactivation which can be fully reversed by adding excess Co2+ or Mn2+ to a 50-fold dilution of the denaturing medium. Titration of the denatured enzyme with either Co2+ or Mn2+ shows that wheat germ mutase preferentially binds Co2+. Assuming 1:1 complexation between metal atom and protein, the apparent dissociation constants (Kd) for E Co2+ and E Mn2+ at 22 degrees C and pH 8.7 are approximately 1.06 and 1.84, respectively. Other metal atoms (e.g., Cr2+, Cu2+, Fe2+, Fe3+, Mg2+, and Ni2+) have no effect in restoring the apoenzyme's catalytic activity. At low concentrations (0.11-0.23 mM) Zn2+ partially restores activity, but promotes protein precipitation at elevated concentrations. Evidence suggests that all bisphosphoglycerate-independent phosphoglycerate mutases require either an intra- or an extramolecular metal atom in order to function. Attempts to characterize wheat germ mutase as a glycoprotein have yielded negative results. PMID:3010970

  18. Vanadocene-mediated in vivo male germ cell apoptosis.

    PubMed

    D'Cruz, O J; Uckun, F M

    2000-08-01

    Vanadocenes are potent apoptosis-inducing cytotoxic agents against human testicular cancer cells in vitro. The present study investigated the ability of four vanadocenes-vanadocene diazide (VDA), vanadocene dicyanate (VDCN), vanadocene dioxycyanate (VDOCN), and vanadocene monochloro oxycyanate (VDCO)-to induce male germ cell apoptosis in vivo in mouse testes by repetitive intratesticular injection of vanadocenes (7.5 mg/kg/testis) for 28 days. Germ cell loss in vivo was measured by epididymal sperm count, testes weights, and histologic evaluation of the testes. Repetitive intratesticular injection of vanadocenes led to decreased sperm counts and reduced testicular weights. Histopathological examination revealed seminiferous tubular atrophy, inhibition of spermatogenesis, and the preferential loss of maturing and elongated spermatids. In situ evaluation by the terminal deoxynucleotidyl transferase-mediated FITC-deoxyuridine triphosphate nick-end labeling (TUNEL) of seminiferous tubule cross sections and laser confocal microscopy showed characteristic apoptotic cells identified primarily as pachytene spermatocytes delineating the periphery of the seminiferous tubules. The ability of vanadocenes to induce germ cell apoptosis in vivo may have potential utility in the treatment of testicular seminomas in humans. PMID:10906282

  19. 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.

  20. Effect of sourdough fermentation on stabilisation, and chemical and nutritional characteristics of wheat germ

    Microsoft Academic Search

    Carlo Giuseppe Rizzello; Luana Nionelli; Rossana Coda; Maria De Angelis; Marco Gobbetti

    2010-01-01

    Lactic acid bacteria strains were identified from wheat germ by 16S rRNA partial sequencing, subjected to RAPD-PCR typing and screened. Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5 were used as starters to produce sourdough fermented wheat germ (SFWG). The chemical and nutritional characteristics of SFWG were compared to those of the raw wheat germ (RWG). Lipase activity in SFWG was

  1. Criteria for right–left equivalence of smooth map-germs

    Microsoft Academic Search

    Takashi Nishimura

    2001-01-01

    We propose a simple systematic method for giving affirmative answers to the recognition problem on Cr right–left equivalence of two given C? map-germs by constructing germs of Cr diffeomorphisms directly from a given CrK-equivalence (1?r??). By using this method, we shall give several sufficient conditions for Cr right–left equivalence of two given C? map-germs. In the case that r=?, our

  2. Germ Cell Migration in Zebrafish Is Dependent on HMGCoA Reductase Activity and Prenylation

    Microsoft Academic Search

    Juanita L Thorpe; Maria Doitsidou; Shiu-Ying Ho; Eraz Raz; Steven A Farber

    2004-01-01

    Hydroxymethylglutaryl coenzyme A reductase (HMGCoAR) is required for isoprenoid and cholesterol biosynthesis. In Drosophila, reduced HMGCoAR activity results in germ cell migration defects. We show that pharmacological HMGCoAR inhibition alters zebrafish development and germ cell migration. Embryos treated with atorvastatin (Lipitor) exhibited germ cell migration defects and mild morphologic abnormalities. The effects induced by atorvastatin were completely rescued by prior

  3. The Drosophila stonewall gene encodes a putative transcription factor essential for germ cell development.

    PubMed

    Clark, K A; McKearin, D M

    1996-03-01

    The differentiation of Drosophila germ cells is a useful model for studying mechanisms of cell specification. We report the identification of a gene, stonewall, that is required for germ cell development. Mutations in stonewall block proper oocyte differentiation and frequently cause the presumptive oocyte to develop as a nurse cell. Eventually, germ cells degenerate apoptotically. Stonewall is a germ cell nuclear protein; Stonewall has a DNA binding domain that shows similarities to the Myb and Adf-1 transcription factors and has other features that suggest that it is a transcription activating factor. We suggest that Stonewall transcriptional regulation is essential in cystocytes for maturation into specialized nurse cells and oocyte. PMID:8631271

  4. 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

  5. Effect of lectins and sugars on primary sperm attachment in the horseshoe crab, Limulus polyphemus L.

    PubMed

    Barnum, S R; Brown, G G

    1983-02-01

    The apical regions of motile Limulus spermatozoa readily adhere to the outer layer of the egg envelope. Shortly after this adherence or primary attachment, the sperm acrosome reaction occurs, resulting in a stronger adhesion (secondary attachment). A sperm attachment assay that quantified the number of spermatozoa attaching to egg sections was utilized to identify components involved in primary attachment. The number of spermatozoa attached was examined after treatment of either egg sections or spermatozoa with various compounds. Egg sections treated with asparagus pea lectin (250 micrograms/ml) bound significantly fewer spermatozoa as compared to those exposed to wheat germ agglutinin, concanavalin A, and garden pea lectin. Furthermore, sperm attachment was also greatly reduced when egg sections were first incubated with the glycosidase, alpha-L-fucosidase (less than or equal to 5% of controls). Treatment of spermatozoa with alpha-L-fucose, fucoidan, or p-aminophenyl fucoside also reduced sperm attachment when compared to Millipore-filtered artificial seawater controls. Egg sections were treated with fluorescein-conjugated lectins to confirm that the lectins actually bound to portions of the egg envelope and that various sugars are present in the egg envelope. Evidence suggests that the methylpentose, alpha-L-fucose, plays an important role in primary sperm attachment in Limulus. PMID:6687461

  6. Development and evolution of the vertebrate primary mouth

    PubMed Central

    Soukup, Vladimír; Horácek, Ivan; Cerny, Robert

    2013-01-01

    The vertebrate oral region represents a key interface between outer and inner environments, and its structural and functional design is among the limiting factors for survival of its owners. Both formation of the respective oral opening (primary mouth) and establishment of the food-processing apparatus (secondary mouth) require interplay between several embryonic tissues and complex embryonic rearrangements. Although many aspects of the secondary mouth formation, including development of the jaws, teeth or taste buds, are known in considerable detail, general knowledge about primary mouth formation is regrettably low. In this paper, primary mouth formation is reviewed from a comparative point of view in order to reveal its underestimated morphogenetic diversity among, and also within, particular vertebrate clades. In general, three main developmental modes were identified. The most common is characterized by primary mouth formation via a deeply invaginated ectodermal stomodeum and subsequent rupture of the bilaminar oral membrane. However, in salamander, lungfish and also in some frog species, the mouth develops alternatively via stomodeal collar formation contributed both by the ecto- and endoderm. In ray-finned fishes, on the other hand, the mouth forms via an ectoderm wedge and later horizontal detachment of the initially compressed oral epithelia with probably a mixed germ-layer derivation. A very intriguing situation can be seen in agnathan fishes: whereas lampreys develop their primary mouth in a manner similar to the most common gnathostome pattern, hagfishes seem to undergo a unique oropharyngeal morphogenesis when compared with other vertebrates. In discussing the early formative embryonic correlates of primary mouth formation likely to be responsible for evolutionary–developmental modifications of this area, we stress an essential role of four factors: first, positioning and amount of yolk tissue; closely related to, second, endoderm formation during gastrulation, which initiates the process and constrains possible evolutionary changes within this area; third, incipient structure of the stomodeal primordium at the anterior neural plate border, where the ectoderm component of the prospective primary mouth is formed; and fourth, the prime role of Pitx genes for establishment and later morphogenesis of oral region both in vertebrates and non-vertebrate chordates. PMID:22804777

  7. Aggregation behaviour and stability of maize germ oil body suspension.

    PubMed

    Sukhotu, Rujira; Shi, Xiaodi; Hu, Qi; Nishinari, Katsuyoshi; Fang, Yapeng; Guo, Shuntang

    2014-12-01

    To utilize maize germ oil bodies as ingredients in the food industry, zeta potential determination and particle diameter analysis were used in this study as indicators of the stability of maize germ oil body suspensions. The stability and aggregation properties of maize germ oil body suspensions were studied at different pH and ion strength conditions, and different thermal treatments. Zeta potential measurement, mean particle size determination, and confocal laser scanning microscopy were also performed. The zeta potential and mean particle diameter of the oil bodies were easily affected by salt (7.05 mV and d32=1.43 ?m at 100mM NaCl) and pH (23.30, 15.00, -16.43 mV and d32=1.02, 2.55, and 0.95 ?m at pH 3, pH 4, and pH 7, respectively). Results demonstrated that aggregation and instability of the oil bodies were promoted by high salt concentrations and acidic pH but not by heating. The association between oil bodies and surfactant properties resulted in the disruption of hydrophobic interactions among oil body surface proteins because of the smaller mean particle sizes and the reduced negative charges (-75.73 mV and d32=0.46 ?m at pH 3). Thus, the oil body aggregation behavior and stability of proteins are based on hydrophobic interactions present on the surface of the oil bodies. PMID:24996296

  8. Autophagy and Apoptosis Act as Partners to Induce Germ Cell Death after Heat Stress in Mice

    PubMed Central

    Zhang, Mianqiu; Jiang, Min; Bi, Ye; Zhu, Hui; Zhou, Zuomin; Sha, Jiahao

    2012-01-01

    Testicular heating suppresses spermatogenesis which is marked by germ cell loss via apoptotic pathways. Recently, it is reported that autophagy also can be induced by heat treatment in somatic cells. In this study, the status of autophagy in germ cells after heat treatment, as well as the partnership between autophagy and apoptosis in these cells was investigated. The results demonstrated that besides initiating apoptotic pathways, heat also induced autophagic pathways in germ cells. Exposure of germ cells to hyperthermia resulted in several specific features of the autophagic process, including autophagosome formation and the conversion of LC3-I to LC3-II. Furthermore, the ubiquitin-like protein conjugation system was implicated as being likely responsible for heat-induced autophagy in germ cells since all genes involving this system were found to be expressed in the testes. In addition, the upstream protein in this system, Atg7 (Autophagy-related gene 7), was found to be expressed in all types of spermatogenic cells, and its expression level was positively correlated with the level of autophagy in germ cells. As a result, Atg7 was selected as the investigative target to further analyze the role of autophagy in heat-induced germ cell death. It was shown that down expression of Atg7 protein resulted in the notable decrease in the level of autophagy in heat-treated germ cells, and this down-regulation of autophagy caused by Atg7 knockdown further reduced the apoptotic rate of germ cells. These results suggest that autophagy plays a positive role in the process of germ cell apoptosis after heat treatment. In conclusion, this study demonstrates that heat triggers autophagy and apoptosis in germ cells. These two mechanisms might act as partners, not antagonist, to induce cell death and lead to eventual destruction of spermatogenesis. PMID:22848486

  9. Magnetite nanoparticles coated with ruthenium via SePh layer as a magnetically retrievable catalyst for the selective synthesis of primary amides in an aqueous medium.

    PubMed

    Joshi, Hemant; Sharma, Kamal Nayan; Sharma, Alpesh K; Prakash, Om; Kumar, Arvind; Singh, Ajai Kumar

    2014-08-28

    The nanostructured magnetic oxide Fe3O4 has been coated with silica and then reacted with phenylselenyl chloride under a N2 atmosphere and RuCl3·xH2O successively in an aqueous medium to prepare Fe3O4@SiO2@SePh@Ru(OH)x nanoparticles (NPs) for the first time. These magnetically retrievable NPs have been authenticated using TEM, SEM-EDX and powder-XRD and found to be an efficient catalyst for one pot conversion (organic solvent not required) of aldehydes, nitriles and benzyl amine to primary amides in water. For aldehydes and nitriles, the yields of primary amides are up to 93%. These NPs can be recycled more than 7 times for the conversion of benzonitrile to the corresponding amide. Gram-scale transformation carried out by using Fe3O4@SiO2@SePh@Ru(OH)x NPs as a catalyst gives ?86% yield. PMID:24989230

  10. Germ-line transmission of transgenes in Xenopus laevis

    PubMed Central

    Marsh-Armstrong, Nicholas; Huang, Haochu; Berry, Deborah L.; Brown, Donald D.

    1999-01-01

    Adult Xenopus laevis frogs made transgenic by restriction enzyme-mediated integration were bred to test the feasibility of establishing lines of frogs that express transgenes. All of the 19 animals raised to sexual maturity generated progeny that expressed the transgene(s). The patterns and levels of expression of green fluorescent protein transgenes driven by a viral promoter, rat promoter, and four X. laevis promoters were all unaffected by passage through the germ line. These results demonstrate the ease of establishing transgenic lines in X. laevis. PMID:10588715

  11. Changes in the number of germ cells in the gonads of the rainbow trout (Salmo gairdneri)

    E-print Network

    Paris-Sud XI, Université de

    Changes in the number of germ cells in the gonads of the rainbow trout (Salmo gairdneri) during of female meiotic prophase. The mean diameters are shown in table 1. The number of germ cells increased in the gonads of rainbow trout (Salmo gairdnen1 fry during the first 10 post-hatching weeks. Material

  12. PROTEIN DISTRIBUTION IN COMMERCIAL WET- AND DRY-MILLED CORN GERM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The total protein content of the corn germ from both wet-, and dry-milling processes is usually between 14 and 16 wt% but there is significant loss of proteins in the wet milling process. Unfortunately little information is available regarding the fate of corn germ proteins as a result of processing...

  13. Digestive enzymes in the germ-free animal T. CORRING, Catherine JUSTE, C. SIMOES-NUNES

    E-print Network

    Paris-Sud XI, Université de

    Digestive enzymes in the germ-free animal T. CORRING, Catherine JUSTE, C. SIMOES-NUNES Laboratoire de Physiologie de la Nutrition, INRA, 78350 Jouy en Josas, France. Summary. The digestive physiology on digestive enzymes in the germ-free. The present paper analyzes these data. There is little information

  14. Allergic Sensitization to Bovine ?-Lactoglobulin: Comparison between Germ-Free and Conventional BALB\\/c Mice

    Microsoft Academic Search

    S. Hazebrouck; L. Przybylski-Nicaise; S. Ah-Leung; K. Adel-Patient; G. Corthier; J.-M. Wal; S. Rabot

    2009-01-01

    Background: The ‘hygiene hypothesis’ suggests that high hygienic standards met in western countries lead to a lack of microbial exposure, thus promoting the development of atopy by preventing the proper maturation of the immune system. Germ-free animals are deprived of the immune stimulation that occurs during postnatal gut colonization by commensal bacteria. Germ-free mice could thereby provide an attractive model

  15. UTR of nanos2 directs enrichment in the germ cell lineage of the sea urchin

    E-print Network

    Wessel, Gary M.

    The 30 UTR of nanos2 directs enrichment in the germ cell lineage of the sea urchin Nathalie Oulhen Keywords: Nanos Sea urchin Small micromeres Germ line RNA retention Translational regulation a b s t r a c during embryogenesis. Three nanos homologs are present in the genome of the sea urchin Strongylo

  16. Synchronous appearance of germ cell tumor and papillary carcinoma of the thyroid

    Microsoft Academic Search

    Jean-Pierre Ayoub; Robert J. Amato; Alice Chiu; Rena V. Sellin; Randal S. Weber

    2000-01-01

    Synchronous appearance of 2 different malignancies in one patient is a rare phenomenon. We describe our experience of 2 patients with synchronous malignancies of the testis and thyroid gland, and of a third patient who developed a thyroid neoplasm unrelated to recent treatment for a germ cell tumor. The medical records of 3 male patients treated for both a germ

  17. The role of the sex chromosomes in mammalian germ cell differentiation

    E-print Network

    Paris-Sud XI, Université de

    The role of the sex chromosomes in mammalian germ cell differentiation P. S. BURGOYNE Department and their sex-chromosomal make-up. It is concluded that germ cells in an ovary require two functional X have sterile testes. Ohno (1969) has presented evidence that the genetic content of the sex chromo

  18. Acoustic Emission of Non-Spherical Germs During Phases Formation in Solids

    Microsoft Academic Search

    Alexey Yu. Ivanov; A. V. Kapytski

    2006-01-01

    The acoustic emission of an ensemble of growing germs of a new phase in elastic medium, initiated by laser treating of solids was investigated. The analysis of acoustic emission showed, that the ensemble of growing genus generates acoustic waves which frequencies omegaE are simply connected with the size R of heterogeneities (germs), and the intensity of each spectral component is

  19. Consumers can protect themselves by preventing the spread of germs by both

    E-print Network

    Stephens, Graeme L.

    Consumers can protect themselves by preventing the spread of germs by both cleaning and sanitizing paper towel. Sanitizing definition: the reduction of germs to a safe level so illness is unlikely, if not deadly, illnesses. Sanitizing steps: (See the table on page two) 1. Spray surface with sanitizer

  20. Derivation of embryonic germ cells and male gametes from embryonic stem cells

    Microsoft Academic Search

    Niels Geijsen; Melissa Horoschak; Kitai Kim; Joost Gribnau; Kevin Eggan; George Q. Daley

    2004-01-01

    Egg and sperm cells (gametes) of the mouse are derived from a founder population of primordial germ cells that are set aside early in embryogenesis. Primordial germ cells arise from the proximal epiblast, a region of the early mouse embryo that also contributes to the first blood lineages of the embryonic yolk sac. Embryonic stem cells differentiate in vitro into

  1. Blimp1 is a critical determinant of the germ cell lineage in mice

    Microsoft Academic Search

    Yasuhide Ohinata; Bernhard Payer; Dónal O'Carroll; Katia Ancelin; Yukiko Ono; Mitsue Sano; Sheila C. Barton; Tetyana Obukhanych; Michel Nussenzweig; Alexander Tarakhovsky; Mitinori Saitou; M. Azim Surani

    2005-01-01

    Germ cell fate in mice is induced in pluripotent epiblast cells in response to signals from extraembryonic tissues. The specification of approximately 40 founder primordial germ cells and their segregation from somatic neighbours are important events in early development. We have proposed that a critical event during this specification includes repression of a somatic programme that is adopted by neighbouring

  2. 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).

  3. 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…

  4. Contribution of METRO pathway localized molecules to the organization of the germ cell lineage

    Microsoft Academic Search

    Malgorzata Kloc; Carolyn Larabell; Agnes Pui-Yee Chan; Laurence D Etkin

    1998-01-01

    To elucidate the potential role of localized components in the specification of the germ cell lineage we analyzed the composition of the germ plasm in Xenopus laevis oocytes and early embryos with respect to the vegetally-localized RNAs. We focused on Xlsirts, Xcat2, and Xwnt11 transcripts that are localized to the vegetal cortex through a region of the mitochondrial cloud called

  5. Clinical Pattern and Therapeutic Results Achieved in 1490 Patients with Germ-Cell Tumours of the Testis: the Experience of the Spanish Germ-Cell Cancer Group (GG)

    Microsoft Academic Search

    J. R Germà-Lluch; X Garcia del Muro; P Maroto; L Paz-Ares; J. A Arranz; J Gumà; E Alba; J Sastre; J Aparicio; A Fernández; A Barnadas; J Terrassa; A Sáenz; D Almenar; M López-Brea; M. A Climent; M. A Sánchez; R Lasso de la Vega; G Berenguer; X Pérez

    2002-01-01

    Objective: To describe the clinical characteristics and treatment results obtained with the application of a homogeneous treatment protocol in 1490 patients with germ-cell tumours (GCT) registered in the 55 hospitals belonging to the Spanish Germ-Cell Cancer Group (GG) during the period between January 1994 and April 2001.Methods: In general, surveillance was the common policy for stage I patients without local

  6. Endogenous interleukin 18 regulates testicular germ cell apoptosis during endotoxemia.

    PubMed

    Inoue, Taketo; Aoyama-Ishikawa, Michiko; Kamoshida, Shingo; Nishino, Satoshi; Sasano, Maki; Oka, Nobuki; Yamashita, Hayato; Kai, Motoki; Nakao, Atsunori; Kotani, Joji; Usami, Makoto

    2015-08-01

    Orchitis (testicular swelling) often occurs during systemic inflammatory conditions, such as sepsis. Interleukin 18 (IL18) is a proinflammatory cytokine and is an apoptotic mediator during endotoxemia, but the role of IL18 in response to inflammation in the testes was unclear. WT and IL18 knockout (KO) mice were injected lipopolysaccharide (LPS) to induce endotoxemia and examined 12 and 48?h after LPS administration to model the acute and recovery phases of endotoxemia. Caspase activation was assessed using immunohistochemistry. Protein and mRNA expression were examined by western blot and quantitative real-time RT-PCR respectively. During the acute phase of endotoxemia, apoptosis (as indicated by caspase-3 cleavage) was increased in WT mice but not in IL18 KO mice. The death receptor-mediated and mitochondrial-mediated apoptotic pathways were both activated in the WT mice but not in the KO mice. During the recovery phase of endotoxemia, apoptosis was observed in the IL18 KO mice but not in the WT mice. Activation of the death-receptor mediated apoptotic pathway could be seen in the IL18 KO mice but not the WT mice. These results suggested that endogenous IL18 induces germ cell apoptosis via death receptor mediated- and mitochondrial-mediated pathways during the acute phase of endotoxemia and suppresses germ cell apoptosis via death-receptor mediated pathways during recovery from endotoxemia. Taken together, IL18 could be a new therapeutic target to prevent orchitis during endotoxemia. PMID:25934945

  7. Issues in identifying germ tube positive yeasts by conventional methods.

    PubMed

    Yazdanpanah, Atta; Khaithir, Tzar Mohd Nizam

    2014-01-01

    Candida speciation is vital for epidemiology and management of candidiasis. Nonmolecular conventional methods often fail to identify closely related germ tube positive yeasts from clinical specimens. The present study was conducted to identify these yeasts and to highlight issues in conventional versus molecular methods of identification. A total of 98 germ tube positive yeasts from high vaginal swabs were studied over a 12-month period. Isolates were examined with various methods including growth at 42 °C and 45 °C on Sabouraud dextrose agar (SDA), color development on CHROMagar Candida medium, chlamydospore production on corn meal agar at 25 °C, carbohydrate assimilation using ID 32C system, and polymerase chain reaction using a single pair of primers targeting the hyphal wall protein 1 (Hwp1) gene. Of all the isolates studied, 97 were molecularly confirmed as C. albicans and one isolate was identified as C. dubliniensis. No C. africana was detected in this study. The molecular method used in our study was an accurate and useful tool for discriminating C. albicans, C. dubliniensis, and C. africana. The conventional methods, however, were less accurate and riddled with many issues that will be discussed in further details. PMID:24375729

  8. Somatic mutations of KIT in familial testicular germ cell tumours.

    PubMed

    Rapley, E A; Hockley, S; Warren, W; Johnson, L; Huddart, R; Crockford, G; Forman, D; Leahy, M G; Oliver, D T; Tucker, K; Friedlander, M; Phillips, K-A; Hogg, D; Jewett, M A S; Lohynska, R; Daugaard, G; Richard, S; Heidenreich, A; Geczi, L; Bodrogi, I; Olah, E; Ormiston, W J; Daly, P A; Looijenga, L H J; Guilford, P; Aass, N; Fosså, S D; Heimdal, K; Tjulandin, S A; Liubchenko, L; Stoll, H; Weber, W; Einhorn, L; Weber, B L; McMaster, M; Greene, M H; Bishop, D T; Easton, D; Stratton, M R

    2004-06-14

    Somatic mutations of the KIT gene have been reported in mast cell diseases and gastrointestinal stromal tumours. Recently, they have also been found in mediastinal and testicular germ cell tumours (TGCTs), particularly in cases with bilateral disease. We screened the KIT coding sequence (except exon 1) for germline mutations in 240 pedigrees with two or more cases of TGCT. No germline mutations were found. Exons 10, 11 and 17 of KIT were examined for somatic mutations in 123 TGCT from 93 multiple-case testicular cancer families. Five somatic mutations were identified; four were missense amino-acid substitutions in exon 17 and one was a 12 bp in-frame deletion in exon 11. Two of seven TGCT from cases with bilateral disease carried KIT mutations compared with three out of 116 unilateral cases (P=0.026). The results indicate that somatic KIT mutations are implicated in the development of a minority of familial as well as sporadic TGCT. They also lend support to the hypothesis that KIT mutations primarily take place during embryogenesis such that primordial germ cells with KIT mutations are distributed to both testes. PMID:15150569

  9. Bone disease in testicular and extragonadal germ cell tumours.

    PubMed Central

    Hitchins, R. N.; Philip, P. A.; Wignall, B.; Newlands, E. S.; Begent, R. H.; Rustin, G. J.; Bagshawe, K. D.

    1988-01-01

    Of 297 patients with metastatic testicular and extragonadal germ cell tumours (GCT), bone involvement was detected clinically in 3% (7/251) of those at first presentation and in 9% (4/46) of relapsed cases. This difference was not statistically significant (95% confidence limits -2%; +14%). Concurrent systemic metastases, commonly involving lung (7/11 cases) and para-aortic lymph nodes (6/11), were present in all patients with bone disease. All affected patients had localized bone pain and lumbar spine was the most frequent site involved (9/11). Spinal cord compression occurred in two patients while a third developed progressive vertebral collapse after chemotherapy and required extensive surgical reconstruction. At median follow-up of 4 years, survival among patients presenting with bone disease (6/7) was similar to overall survival in the whole group (84%) and appeared better than in those with liver (18/26, 69%) or central nervous system (6/9) metastases at presentation. Back pain in metastatic germ cell tumours is often due to retroperitoneal lymphadenopathy but lumbar spine osseus metastases must be recognized early if severe potential complications, such as spinal cord compression, are to be avoided. In this series, bone metastases were not seen in the absence of widespread systemic disease suggesting all solitary bony lesions in GCT patients should be biopsied. Images Figure 1 Figure 2 PMID:3224081

  10. Retroperitoneal lymph node dissection for metastatic germ cell tumours

    PubMed Central

    Haldipur, N; Devaraj, S; Shehata, A; Lewis, AK; Smith, MO; Hatton, M; Nassef, A; Beard, JD

    2011-01-01

    INTRODUCTION In the North Trent Cancer Network (NTCN) patients requiring retroperitoneal lymphadenectomy for metastatic testicular cancer have been treated by vascular service since 1990. This paper reviews our experience and considers the case for involvement of vascular surgeons in the management of these tumours. PATIENTS AND METHODS Patients referred by the NTCN to the vascular service for retroperitoneal lymphadenectomy between 1990 and 2009 were identified through a germ cell database. Data were supplemented by a review of case notes to record histology, intraoperative and postoperative details. RESULTS A total of 64 patients were referred to the vascular service for retroperitoneal lymph node dissection, with a median age of 29 years (16–63 years) and a median follow-up of 4.9 years. Ten patients died: eight from tumour recurrence, one from septicaemia during chemotherapy and one by suicide. Of the 54 who survived, 7 were alive with residual masses and 47 patients were disease-free at the last follow-up. Sixteen patients required vascular procedures: four had aortic repair (fascia), three had aortic replacement (spiral graft), four had inferior vena cava resection, two had iliac artery replacement and two had iliac vein resection. CONCLUSIONS Retroperitoneal lymph node dissection often involves mobilisation and/or the resection/replacement of major vessels. We recommend that a vascular surgeon should be a part of testicular germ cell multidisciplinary team. PMID:21944797

  11. Endocrine disruptors, gene deregulation and male germ cell tumors.

    PubMed

    Del-Mazo, Jesús; Brieño-Enríquez, Miguel A; García-López, Jesús; López-Fernández, Luis A; De-Felici, Massimo

    2013-01-01

    Endocrine disruptors (EDs) belong to a large group of compounds, usually present as environmental pollutants, which can alter the homeostasis of living organisms by modifying hormonal balance and changing the normal patterns of gene regulation during development and cell differentiation. Hence, the development of male gonads and their functionality may be affected by exposure to specific EDs or their mixtures. The molecular mechanisms of action of these reprotoxicants leading to pathologies of the reproductive system such as testicular cancer, are complex and not well characterized. It is likely, however, that these compounds alter the interaction between the mechanisms of gene regulation and functional gene networks in windows of risk, mainly during embryonic development. Moreover, such changes could be transmitted through generations by epigenetic mechanisms. There are examples of the action of EDs on the expression of mRNAs, small non-coding RNAs and epigenetic marks in the developing testis associated with cellular and molecular alterations found in germ cell tumors. In the present review, we will discuss various aspects of genetic, transcriptomic and epigenetic changes related to testicular development, exposure to EDs and the occurrence of germ cell tumors. PMID:23784834

  12. Using Microwave Heating and Microscopy to Estimate Optimal Corn Germ Oil Yield with a Bench-Scale Press

    Microsoft Academic Search

    L. C. Dickey; P. H. Cooke; M. J. Kurantz; A. McAloon; N. Parris; R. A. Moreau

    2007-01-01

    The increase in ethanol production from corn has prompted development of processes to separate corn germ. The corn germ co-product\\u000a would be a source of corn oil if a practical oil separation process were also developed. We carried out bench-scale corn-germ-pressing\\u000a experiments to determine the maximum potential oil recovery which were then used to estimate commercial germ crushing costs.\\u000a Corn

  13. Male germ-like cell differentiation potential of human umbilical cord Wharton’s jelly-derived mesenchymal stem cells in co-culture with human placenta cells in presence of BMP4 and retinoic acid

    PubMed Central

    nejad, Nahid Ataie; Amidi, Fardin; Hoseini, Marziyeh Agha; Nia, Karim Nayer; Habibi, Mehryar; Kajbafzadeh, Abdol Mohammad; Mazaheri, Zohreh; Yamini, Nazila

    2015-01-01

    Objective(s): Mesenchymal stem cells (MSCs) derived from Wharton’s jelly (WJ-MSCs) are now much more appealing for cell-based infertility therapy. Hence, WJ-MSCs differentiation toward germ layer cells for cell therapy purposes is currently under intensive study. Materials and Methods: MSCs were isolated from human Wharton’s jelly and treated with BMP4, retinoic acid (RA) or co-cultured on human amniotic epithelial (HAE) and chorionic plate (HCP) placenta feeder cells. profile of POU5F1, Fragilis, Plzf, DDX4, Piwil2, Stra8, Dazl, ?1- and ?6-integrins (IT?1, ITA6) genes expression as germ cell markers were analyzed using RT-PCR and real-time PCR. Immunocytochemistry of surface markers were conducted. Results: After 3 weeks treatment with different reagents and co-culture system, morphology of WJ-MSCs changed to shiny clusters and germ cell specific markers in mRNA were up-regulated in both placental feeder + RA and BMP4 + RA. Induction of hWJ-MSCs with BMP4 in presence of RA resulted in significant up-regulation (P?0.05) of all germ cell specific genes (c-Kit; 2.84±0.59, DDX4; 1.69±0.39, Piwil2; 1.14±0.21, Dazl; 0.65±0.25, ?6 integrin; 1.26±0.53, ?1 integrins; 1.18±0.65) compared to control and placental feeder cells + RA. Our results indicated that HAE and HCP followed by RA treatment were involved in human germ cell development. Conclusion: We demonstrated that under the right conditions, hWJ-MSCs have the ability to differentiate to germ cells and this provides an excellent pattern to study infertility cause and treatment. PMID:26019794

  14. Production of maternal-zygotic mutant zebrafish by germ-line replacement

    PubMed Central

    Ciruna, Brian; Weidinger, Gilbert; Knaut, Holger; Thisse, Bernard; Thisse, Christine; Raz, Erez; Schier, Alexander F.

    2002-01-01

    We report a generally applicable strategy for transferring zygotic lethal mutations through the zebrafish germ line. By using a morpholino oligonucleotide that blocks primordial germ cell (PGC) development, we generate embryos devoid of endogenous PGCs to serve as hosts for the transplantation of germ cells derived from homozygous mutant donors. Successful transfers are identified by the localization of specifically labeled donor PGCs to the region of the developing gonad in chimeric embryos. This strategy, which results in the complete replacement of the host germ line with donor PGCs, was validated by the generation of maternal and maternal-zygotic mutants for the miles apart locus. This germ-line replacement technique provides a powerful tool for studying the maternal effects of zygotic lethal mutations. Furthermore, the ability to generate large clutches of purely mutant embryos will greatly facilitate embryological, genetic, genomic, and biochemical studies. PMID:12397179

  15. 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

  16. Removal and isolation of germ-rich fractions from hull-less barley using a fitzpatrick comminuting mill

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A process was developed to produce a germ-enriched fraction from hull-less barley using a Fitzpatrick Comminuting Mill followed by sieving. Hulled and hull-less barleys contain 1.5-2.5% oil and, like wheat kernels which contain wheat germ oil, much of the oil in barley kernels is in the germ fracti...

  17. Oocytes and embryos of Xenopus laevis express two different isoforms of germ cell nuclear factor (GCNF, NR6A1)

    Microsoft Academic Search

    Anne Schohl; Guillermo Barreto; Thomas O Joos; Christine Dreyer

    2002-01-01

    The germ cell nuclear factor (GCNF) is a nuclear orphan receptor and a putative regulator of the pluripotent state of cells. Although it was first described in mouse germ cells, GCNF is also expressed in mouse and Xenopus embryos. By means of 5?RACE we have identified a novel isoform of Xenopus laevis GCNF that is predominantly expressed in germ cells,

  18. 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.

  19. Sex-Specific Dynamics of Global Chromatin Changes in Fetal Mouse Germ Cells

    PubMed Central

    Jin, Seung-Gi; Pfeifer, Gerd P.; Szabó, Piroska E.

    2011-01-01

    Mammalian germ cells undergo global reprogramming of DNA methylation during their development. Global DNA demethylation occurs around the time when the primordial germ cells colonize the embryonic gonads and this coincides with dynamic changes in chromatin composition. Global de novo DNA methylation takes place with remarkably different dynamics between the two sexes, prospermatogonia attaining methylation during fetal stages and oocytes attaining methylation postnatally. Our hypothesis was that dynamic changes in chromatin composition may precede or accompany the wave of global DNA de novo methylation as well. We used immunocytochemistry to measure global DNA methylation and chromatin components in male and female mouse fetal germ cells compared to control somatic cells of the gonad. We found that global DNA methylation levels sharply increased in male germ cells at 17.5 days post coitum, but remained low in female germ cells at all fetal stages. Global changes in chromatin composition: i, preceded global DNA methylation in fetal germ cells; ii, sex specifically occurred in male but not in female germ cells; iii, affected active and repressive histone marks and iv, included histone tail and histone globular domain modifications. Our data suggest that dynamic changes of chromatin composition may provide a framework for the pattern of male-specific de novo DNA methylation in prospermatogonia. PMID:21886830

  20. Germ-granule components prevent somatic development in the C. elegans germline

    PubMed Central

    Knutson, Andrew Kek?pa'a; Egelhofer, Thea A.; Campbell, Anne C.; Strome, Susan

    2014-01-01

    Summary Specialized ribonucleoprotein organelles collectively known as germ granules are found in the germline cytoplasm from worms to humans [1]. In Drosophila, germ granules have been implicated in germline determination [2]. C. elegans germ granules, known as P granules, do not appear to be required for primordial germ cell (PGC) determination [3], but their components are still needed for fertility [4–6]. One potential role for P granules is to maintain germline fate and totipotency. This is suggested by the loss of P granules from germ cells that transform into somatic cell types, e.g. in germlines lacking MEX-3 and GLD-1 or upon neuronal induction by CHE-1 [7, 8]. However, it has not been established whether loss of P granules is the cause or effect of cell-fate transformation. To test cause-effect, we severely compromised P granules by simultaneously knocking down factors that nucleate granule formation (PGL-1 and PGL-3) and promote their perinuclear localization (GLH-1 and GLH-4) [9], and investigated if that causes germ cells to lose totipotency and initiate somatic reprogramming. We found that compromising P granules causes germ cells to express neuronal and muscle markers and send out neurite-like projections, suggesting that P granules maintain totipotency and germline identity by antagonizing somatic fate. PMID:24746798

  1. The Fog-3 Gene and Regulation of Cell Fate in the Germ Line of Caenorhabditis Elegans

    PubMed Central

    Ellis, R. E.; Kimble, J.

    1995-01-01

    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 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. PMID:7713418

  2. Antibodies to wheat germ agglutinin in coeliac disease.

    PubMed Central

    Sollid, L M; Kolberg, J; Scott, H; Ek, J; Fausa, O; Brandtzaeg, P

    1986-01-01

    Serum IgG and IgA antibodies to wheat germ agglutinin (WGA) were measured by an enzyme-linked immunosorbent assay (ELISA) with N-acetyl-D-glucosamine in all incubation steps to inhibit sugar-specific binding. Patients with coeliac disease (CD) had significantly higher antibody levels to WGA than patients with other intestinal disorders or healthy controls. Similar results were obtained for antibodies to the gluten fraction glyc-gli. The WGA antibodies did apparently not cross-react with gluten antigens, but commercial gluten powder contained traces of WGA or a similar lectin. Our findings support the proposal that WGA may be involved in the pathogenesis of CD. PMID:3754186

  3. Zebrafish Germline Chimeras Produced by Transplantation of Ovarian Germ Cells into Sterile Host Larvae1

    PubMed Central

    Wong, Ten-Tsao; Saito, Taiju; Crodian, Jennifer; Collodi, Paul

    2011-01-01

    High frequency production of zebrafish germline chimeras was achieved by transplanting ovarian germ cells into sterile Danio hybrid recipients. Ovarian germ cells were obtained from 3-mo-old adult Tg(vasa:DsRed2-vasa);Tg(bactin:EGFP) double transgenic zebrafish by discontinuous Percoll gradient centrifugation. An average of 755 ± 108 DsRed-positive germ cells was recovered from each female. For transplantations, a total of approximately 620 ± 242 EGFP-positive cells of which 12 ± 4.7 were DsRed-positive germ cells were introduced into the abdominal cavity under the swim bladder of 2-wk-old sterile hybrid larvae. Six weeks after transplantation, a total of 10 recipients, obtained from 2 different transplantations, were examined, and 2 individuals (20%) were identified that possessed a large number of DsRed- and EGFP-positive cells in the gonadal region. The transplanted ovarian germ cells successfully colonized the gonads and differentiated into sperm in the male hybrid recipients. Of 67 adult recipients, 12 (18%) male chimeric fish reproduced and generated normal offspring when paired with wild-type zebrafish females. The fertilization efficiency ranged from 23% to 56%. Although the fertile male chimeras were generated by transplantation of ovarian germ cells, the F1 generation produced by the male chimeras contained both male and female progeny, indicating that male sex determination in zebrafish is not controlled by sex chromosome heterogamy. Our findings indicate that a population of ovarian germ cells that are present in the ovary of adult zebrafish can function as germline stem cells, able to proliferate and differentiate into testicular germ cells and functional sperm in male recipients. The high frequency of germline chimera formation achieved with the ovarian germ cells and the convenience of identifying the chimeras in the sterile host background should make this transplantation system useful for performing genetic manipulations in zebrafish. PMID:21248287

  4. Primordial germ cells of the rabbit are specifically recognized by a monoclonal antibody labelling the perimitochondrial cytoplasm.

    PubMed

    Viebahn, C; Miething, A; Wartenberg, H

    1998-01-01

    Instrumental for studies investigating the development of germ cells, and especially the separation of the germline in the early embryo, are molecular markers which reliably label germ cells and with which regulative factors of germ cell development may be analyzed. Here, we describe the monoclonal antibody PG-2, which is highly specific for the germ cells of the rabbit embryo and labels the perimitochondrial cytoplasm, as demonstrated by immunogold-silver staining. Identical expression patterns are found in germ cells of either sex from early organogenesis at 10 days post-conception (d.p.c.), when the germ cells leave the hindgut epithelium and settle in the gonadal anlage as primordial germ cells (PGCs), until the time immediately prior to birth (30 d.p.c.), when germ cells are either in their oogonial or prospermatogonial state. The antibody is the first to recognize specifically a cytoplasmic epitope in germ cells of a higher vertebrate and may well recognize the mammalian equivalent of the germ plasm found in invertebrates and lower vertebrates. The antibody can be used for early identification of PGCs and may be of help in the elucidation of mammalian germ cell development towards the gonial stages of spermatogenesis and oogenesis. PMID:9452955

  5. Testisin, a new human serine proteinase expressed by premeiotic testicular germ cells and lost in testicular germ cell tumors.

    PubMed

    Hooper, J D; Nicol, D L; Dickinson, J L; Eyre, H J; Scarman, A L; Normyle, J F; Stuttgen, M A; Douglas, M L; Loveland, K A; Sutherland, G R; Antalis, T M

    1999-07-01

    We have cloned and characterized a cDNA encoding a new human serine proteinase, testisin, that is abundantly expressed only in the testis and is lost in testicular tumors. The testisin cDNA was identified by homology cloning using degenerate primers directed at conserved sequence motifs within the catalytic regions of serine proteinases. It is 1073 nucleotides long, including 942 nucleotides of open reading frame and a 113-nucleotide 3' untranslated sequence. Northern and dot blot analyses of RNA from a range of normal human tissues revealed a 1.4-kb mRNA species that was present only in testis, which was not detected in eight of eight testicular tumors. Testisin cDNA is predicted to encode a protein of 314 amino acids, which consists of a 19-amino acid (aa) signal peptide, a 22-aa proregion, and a 273-aa catalytic domain, including a unique 17-aa COOH-terminal hydrophobic extension that is predicted to function as a membrane anchor. The deduced amino acid sequence of testisin shows 44% identity to prostasin and contains features that are typical of serine proteinases with trypsin-like substrate specificity. Antipeptide antibodies directed against the testisin polypeptide detected an immunoreactive testisin protein of Mr 35,000-39,000 in cell lysates from COS-7 cells that were transiently transfected with testisin cDNA. Immunostaining of normal testicular tissue showed that testisin was expressed in the cytoplasm and on the plasma membrane of premeiotic germ cells. No staining was detected in eight of eight germ cell-derived testicular tumors. In addition, the testisin gene was localized by fluorescence in situ hybridization to the short arm of human chromosome 16 (16p13.3), a region that has been associated with allellic imbalance and loss of heterozygosity in sporadic testicular tumors. These findings demonstrate a new cell surface serine proteinase, loss of which may have a direct or indirect role in the progression of testicular tumors of germ cell origin. PMID:10397266

  6. "Burned out" testicular seminoma presenting as a primary gastric malignancy.

    PubMed

    Mesa, Hector; Rawal, Ajay; Rezcallah, Anthony; Iwamoto, Carlos; Niehans, Gloria A; Druck, Paul; Gupta, Pankaj

    2009-02-01

    In contrast to primary gastric adenocarcinomas, germ cell tumors are potentially curable even when metastatic. It is therefore essential for clinicians and pathologists to be aware of the spectrum of unusual manifestations of germ cell malignancies. Here we report on a 55-year-old man who presented with clinical and endoscopic features indicative of a primary gastric carcinoma. Surprisingly, the ulcerative mucosal lesion was found to be due to a metastasis from an occult, "burned-out" testicular seminoma. This case describes the radiological and pathological features that helped differentiate this rare situation from the much more common gastric adenocarcinoma, and extends the diagnostic possibilities that must be considered in patients presenting with gastric ulcers. PMID:19225929

  7. 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 epidermis. PMID:22911798

  8. The tumor microenvironment: possible role of integrins and the extracellular matrix in tumor biological behavior of intratubular germ cell neoplasia and testicular seminomas.

    PubMed Central

    Timmer, A.; Oosterhuis, J. W.; Schraffordt Koops, H.; Sleijfer, D. T.; Szabo, B. G.; Timens, W.

    1994-01-01

    In the present study, we examined the distribution of integrin subunits and extracellular matrix proteins in normal testis, intratubular germ cell neoplasia (ITGCN), and primary and metastatic seminomas. Compared to normal testis in ITGCN, Sertoli cells showed increased expression of alpha 3, alpha 6, and beta 1 integrin subunits. Malignant intratubular germ cells stained for alpha 3, alpha 6, and beta 1 integrin subunits. Progression of ITGCN to invasive seminoma was associated with loss of alpha 3 integrin subunit expression by tumor cells. Consequent to this loss, it can be speculated that the strong expression on ITGCN may be related to the noninvasive character of the lesion as is also known from other noninvasive tumors. All tumors showed a strong expression of alpha 6 and beta 1 integrin subunits. The alpha 5 integrin subunit was weakly expressed in primary seminomas in all stages. No differences were observed in integrin expression between primary and metastatic tumors. The distribution of extracellular matrix proteins was heterogeneous and revealed clear architectural differences between seminomas that may reflect different stages of tumor stroma formation. To our knowledge, the results presented in this study provide the first information on the possible role of tumor-extracellular matrix interactions in the biological behavior of ITGCN and testicular seminomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8178927

  9. Moral obligation and the human germ-line gene therapy debate 

    E-print Network

    Clark, Alan B

    1998-01-01

    genetic engineering, there are few arguments made for a positive moral obligation to genetic intervention. This is especially so with respect to human germ-line gene therapy. Burke. K. Zimmerman makes one of the few arguments that society...

  10. 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.

  11. 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.

  12. Moral obligation and the human germ-line gene therapy debate

    E-print Network

    Clark, Alan B

    1998-01-01

    genetic engineering, there are few arguments made for a positive moral obligation to genetic intervention. This is especially so with respect to human germ-line gene therapy. Burke. K. Zimmerman makes one of the few arguments that society...

  13. From medical geography to germ theory in Colombia, 1860-1900 

    E-print Network

    Garcia Lopez, Claudia Monica

    2009-01-01

    Before the consolidation of the germ theory of human diseases at the end of the nineteenth century, medical explanations about disease causation were dominated by the environmental notions of medical geography. This ...

  14. Conservation of Migration and Differentiation Circuits in Primordial Germ Cells Between Avian Species

    PubMed Central

    PARK, Tae Sub; HAN, Jae Yong

    2013-01-01

    Abstract Germ cell differentiation in reverse-sexed reproductive organs and interspecies germ line chimeras provides insight into the mechanism of germ cell development and represents a useful tool for conservation of endangered birds. We investigated the migration and survival capacity of male chicken primordial germ cells (PGCs) in female chicken embryos and in quail and Korean ring-necked pheasant embryos of both sexes. Interestingly, the PGCs were successfully reintroduced in all cases. Furthermore, the cells survived in the recipient gonads until hatching regardless of sex and species of the recipient. In the case of male recipient chickens, PGC-derived offspring were produced. However, the reverse-sexed female chickens, quails and pheasants of both sexes did not generate any male donor PGC-derived progeny. These results suggest that migration and survival circuits in chicken PGCs are conserved in both sexes and between avian species during embryonic development. PMID:23386102

  15. 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-tension anisotropy whereby cells do not globally orient their internal elongation axis towards the amnioserosa, but instead orient this axis perpendicular to the local principal stress direction.

  16. Modeling cell elongation during germ band retraction: cell autonomy versus applied anisotropic stress.

    PubMed

    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-tension anisotropy whereby cells do not globally orient their internal elongation axis towards the amnioserosa, but instead orient this axis perpendicular to the local principal stress direction. PMID:24839394

  17. An Integrative Omics Strategy to Assess the Germ Cell Secretome and to Decipher Sertoli-Germ Cell Crosstalk in the Mammalian Testis

    PubMed Central

    Lavigne, Régis; Hernio, Nolwen; Teixeira-Gomes, Ana-Paula; Dacheux, Jean-Louis; Pineau, Charles

    2014-01-01

    Mammalian spermatogenesis, which takes place in complex testicular structures called seminiferous tubules, is a highly specialized process controlled by the integration of juxtacrine, paracrine and endocrine information. Within the seminiferous tubules, the germ cells and Sertoli cells are surrounded by testicular fluid (TF), which probably contains most of the secreted proteins involved in crosstalk between these cells. It has already been established that germ cells can modulate somatic Sertoli cell function through the secretion of diffusible factors. We studied the germ cell secretome, which was previously considered inaccessible, by analyzing the TF collected by microsurgery in an “integrative omics” strategy combining proteomics, transcriptomics, genomics and interactomics data. This approach identified a set of proteins preferentially secreted by Sertoli cells or germ cells. An interaction network analysis revealed complex, interlaced cell-cell dialog between the secretome and membranome of seminiferous cells, mediated via the TF. We then focused on germ cell-secreted candidate proteins, and we identified several potential interacting partners located on the surface of Sertoli cells. Two interactions, APOH/CDC42 and APP/NGFR, were validated in situ, in a proximity ligation assay (PLA). Our results provide new insight into the crosstalk between germ cells and Sertoli cells occurring during spermatogenesis. Our findings also demonstrate that this “integrative omics” strategy is powerful enough for data mining and highlighting meaningful cell-cell communication events between different types of cells in a complex tissue, via a biological fluid. This integrative strategy could be applied more widely, to gain access to secretomes that have proved difficult to study whilst avoiding the limitations of in vitro culture. PMID:25111155

  18. Caenorhabditis elegans germline patterning requires coordinated development of the somatic gonadal sheath and the germ line

    Microsoft Academic Search

    Darrell J. Killian; E. Jane Albert Hubbard

    2005-01-01

    Interactions between the somatic gonad and the germ line influence the amplification, maintenance, and differentiation of germ cells. In Caenorhabditis elegans, the distal tip cell\\/germline interaction promotes a mitotic fate and\\/or inhibits meiosis through GLP-1\\/Notch signaling. However, GLP-1-mediated signaling alone is not sufficient for a wild-type level of germline proliferation. Here, we provide evidence that specific cells of the somatic

  19. Immunohistochemical localization of murine stage-specific embryonic antigens in human testicular germ cell tumors

    Microsoft Academic Search

    I Damjanov; N Fox; B B Knowles; D Solter; P H Lange; E E Fraley

    1982-01-01

    Monoclonal antibodies raised against and\\/or recognizing stage-specific antigens on preimplantation mouse embryos and stem cells of murine teratocarcinoma were used to localize these antigens immunohistochemically on human testicular germ cell tumors. SSEA-1, the antigen found on mouse embryonal carcinoma (EC) cells and embryonic cells from the 8-cell stage embryo onward, including the fetal primordial germ cells, was detected on yolk

  20. From Young Children’s Ideas about Germs to Ideas Shaping a Learning Environment

    Microsoft Academic Search

    Marida Ergazaki; Konstantina Saltapida; Vassiliki Zogza

    2010-01-01

    This paper is concerned with highlighting young children’s ideas about the nature, location and appearance of germs, as well\\u000a as their reasoning strands about germs’ ontological category and biological functions. Moreover, it is concerned with exploring\\u000a how all these could be taken into account for shaping a potentially fruitful learning environment. Conducting individual,\\u000a semi-structured interviews with 35 preschoolers (age 4.5–5.5)

  1. Effect of diclofenac on germ cell apoptosis following testicular ischemia-reperfusion injury in a rat

    Microsoft Academic Search

    Jorge G. Mogilner; Michael Lurie; Arnold G. Coran; Ofer Nativ; Eitan Shiloni; Igor Sukhotnik

    2006-01-01

    Recent evidence suggests that enhanced cell apoptosis is responsible for germ cell loss following testicular ischemia-reperfusion\\u000a (IR) injury. A nonsteroidal anti-inflammatory drug diclofenac sodium (Voltaren) is a prostaglandin-synthesis inhibitor, which\\u000a is widely used in many testicular disorders. The purpose of the present study was to examine the effect of diclofenac (DIC)\\u000a on germ cell apoptosis in the ischemic and contralateral

  2. Germ-line msh6 Mutations in Colorectal Cancer Families1

    Microsoft Academic Search

    Richard D. Kolodner; Jessica D. Tytell; James L. Schmeits; Michael F. Kane; Ruchira Das Gupta; John Weger; Siobhan Wahlberg; Edward A. Fox; David Peel; Argyrios Ziogas; Judy E. Garber; Sapna Syngal; Hoda Anton-Culver; Frederick P. Li

    Hereditary nonpolyposis colorectal carcinoma (HNPCC) is due primar- ily to inherited mutations in two mismatch repair genes, MSH2 and MLH1, whereas germ-line mutations in other mismatch repair genes are rare. We examined the frequency of germ-line msh6 mutations in a population-based series of 140 colorectal cancer patients, including 45 sporadic cases, 91 familial non-HNPCC cases, and 4 HNPCC cases. Among

  3. Differentiating germ cells can revert into functional stem cells in Drosophila melanogaster ovaries

    Microsoft Academic Search

    Toshie Kai; Allan Spradling

    2004-01-01

    Many tissues including blood, skin, gut and germ cells are continuously maintained by tissue stem cells. Under certain conditions, however, other organs can undergo repair using stem-cell-like progenitors generated by cell de-differentiation. Cell fates have been broadened experimentally, but mechanisms allowing de-differentiation to a stem cell state are poorly known. Germline stem cells begin to differentiate by forming interconnected germ

  4. Cytogenetic Analysis of 124 Prospectively Ascertained Male Germ Cell Tumors1

    Microsoft Academic Search

    Eduardo Rodriguez; Susan Mathew; Victor Reuter; David H. Ilson; George J. Bosl; R. S. K. Chaganti

    We report the cytogenetic analysis of 124 adult male germ cell tumors ascertained consecutively at the Memorial Sloan-Kettering Cancer Center between 1988 and 1990. Biopsies from testicular and extragonadal pri mary and metastatic lesions studied included all histológica! subtypes of germ cell tumors and cases of malignant transformation. Nonrandom numerical and structural chromosomal abnormalities including i(12p), the previously described characteristic

  5. Pathogenesis of Renal Disease Due to Enterohemorrhagic Escherichia coli in Germ-Free Mice

    Microsoft Academic Search

    Kathryn A. Eaton; David I. Friedman; Gayle J. Francis; Jessica S. Tyler; Vincent B. Young; Jennifer Haeger; Galeb Abu-Ali; Thomas S. Whittam

    2008-01-01

    Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that causes hemorrhagic colitis and acute renal failure. We used a germ-free mouse model to investigate the role of host factors, Shiga toxin 2 (Stx2), and bacterial strain in disease due to EHEC. Germ-free male and female Swiss-Webster mice that were 3 days to 12 weeks old were orally inoculated with 1

  6. Serum human chorionic gonadotropin is associated with angiogenesis in germ cell testicular tumors

    Microsoft Academic Search

    Oscar Arrieta; Rosa Mayela Michel Ortega; Julián Ángeles-Sánchez; Cynthia Villarreal-Garza; Alejandro Avilés-Salas; José G Chanona-Vilchis; Elena Aréchaga-Ocampo; Arturo Luévano-González; Miguel Ángel Jiménez; José Luis Aguilar

    2009-01-01

    BACKGROUND: Germ cell testicular tumors have survival rate that diminishes with high tumor marker levels, such as human chorionic gonadotropin (hCG). hCG may regulate vascular neoformation through vascular endothelial growth factor (VEGF). Our purpose was to determine the relationship between hCG serum levels, angiogenesis, and VEGF expression in germ cell testicular tumors. METHODS: We conducted a retrospective study of 101

  7. Effect of argemone oil and argemone alkaloid, sanguinarine on Sertoli-germ cell coculture.

    PubMed

    Mishra, Vivek; Saxena, Daya Krishna; Das, Mukul

    2009-04-25

    Several incidences of reduction in the fertility (sperm count) have been reported in India and worldwide as well. Adulteration of food and consumption of adulterated mustard oil with argemone oil (AO) are presumed to be the factors for reduction in sperm count. In the present study we have studied the exfoliation of germ cells from Sertoli cell, its viability after detachment, cytotoxicity and execution of apoptosis via mitochondrial pathway for different concentration of AO, argemone alkaloid (AA) and its major constituent sanguinarine (SA). A dose dependent increase in germ cell detachment and decrease in viability of detached germ cells were observed (P<0.05). A significant inhibition was observed via 3-(4,5-dimethylthiazol-2-yl)-2,5-dipehyl tetrazolium bromide (MTT) assay in the proliferative activity of germ cell and leakage of cytosolic enzyme was observed via Lactate dehydrogenase(LDH) assay (P<0.05). A time and dose dependent inhibition of mitochondrial membrane potential was observed (P<0.05). Treatment of Sertoli-germ cells with the lowest concentration of AO/AA and SA for 24h resulted in 5.2- , 4.4- and 3.6-fold increase in the percentage of early apoptotic cells, respectively. This increase was enhanced to 8.3, 4.75 and 5.81-fold, respectively at 48 h in detached germ cells undergoing early apoptosis. These results suggest that alterations in germ cell apoptosis by a disruption in contact mediated communication between the Sertoli cells and germ cells, may subsequently lead to testicular impairment. PMID:19429230

  8. Germ cell specific expression of c-kit in the human fetal gonad.

    PubMed

    Robinson, L L; Gaskell, T L; Saunders, P T; Anderson, R A

    2001-09-01

    The proto-oncogene receptor, c-kit, and its ligand have been demonstrated to be essential to the processes of germ cell migration, proliferation and survival in the rodent. The aim of the present study was to investigate the expression of c-kit mRNA and protein in human fetal ovary and testis across the gestational period 13-21 weeks. In the ovary, this crucial period of development spans the transition from oogonial replication by mitosis to primordial follicle formation. In the testis, germ cells (gonocytes) are mitotically active. Expression of c-kit mRNA was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) in both ovary and testis at all gestational ages examined. Testicular germ cell specific expression of c-kit mRNA was confirmed by RT-PCR using specific cell types recovered by laser capture microscopy. The expression of c-kit protein by both male and female germ cells was demonstrated by immunohistochemistry at all gestational ages examined, and was confirmed by immunoblotting. In both, c-kit was localized to the cell membrane except in oocytes within primordial follicles where it was localized to the cytoplasm. These data demonstrate that the expression of c-kit mRNA and protein is germ cell specific in human fetal gonads and are consistent with an important role for the c-kit/kit ligand signalling system in germ cell proliferation and survival in the developing human gonad. PMID:11517291

  9. Malignant mixed germ cell tumour of ovary--an unusual combination and review of literature.

    PubMed

    Goyal, Lajya Devi; Kaur, Sharanjit; Kawatra, Kanwardeep

    2014-01-01

    Mixed germ cell tumours of the ovary are malignant neoplasms of the ovary comprising of two or more types of germ cell components. Most of the malignant mixed germ cell tumours consists of dysgerminoma accompanied by endodermal sinus tumours, immature teratoma or choriocarcinoma. There are only few case reports of mixed germ cell tumours with different combinations of malignant components. We report a very rare case of mixed germ cell tumours consisted of malignant components of endodermal sinus tumour, emryonal carcinoma, and benign component of teratomatuos and trophoblastic differentiation. This is the first case report in the literature with both benign and malignant component of type described to best of our knowledge. Patient was an 18 year old girl, who presented with pain abdomen, abdominal mass and irregular bleeding. Ultrasound and CT scan showed a huge mass with solid and cystic component. Tumour markers i.e alpha feto- protein (AFP), human chorionic gonadotropin (hCG), lactate dehydrogenate (LDH) and Ca-125 were raised. We performed fertility sparing surgery by preserving one ovary, tube and uterus. Conclusion: Malingnant mixed germ cell tumours of ovary are highly aggressive neoplasm and early intervention and fertility sparing surgery is required for any adolescent girl presenting with rapidly enlarging pelvic mass. PMID:25366470

  10. 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 3dph they came into contact with stromal cells. PGCs and stromal cells gradually moved forward from the anus prior to 5dph. At 7-10dph, germ cells were surrounded by stromal cells and the gonadal primordia were formed. In individuals collected at 12dph, 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 7-10dph. We observed double the number of germ cells at 30dph (22±3.2 cells), compared to that at 1dph (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

  11. Germ cells of the centipede Strigamia maritima are specified early in embryonic development

    PubMed Central

    Green, Jack E.; Akam, Michael

    2014-01-01

    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

  12. Beyond the mouse monopoly: studying the male germ line in domestic animal models.

    PubMed

    González, Raquel; Dobrinski, Ina

    2015-05-19

    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

  13. Demonstration and solubilization of antigens expressed primarily on the surfaces of Candida albicans germ tubes.

    PubMed Central

    Smail, E H; Jones, J M

    1984-01-01

    Antisera against mycelial-phase, but not yeast-phase, Candida albicans absorbed with yeast-phase organisms preferentially stained germ tube segments of several strains of mycelial-phase C. albicans by the indirect fluorescent-antibody staining technique. Germ tube segment antigens were not found in significant amounts on blastospore segments or on yeast-phase organisms. Absorption of the mycelial-phase reference sera with yeast-phase C. stellatoidea, but not with C. tropicalis, C. guillermondii, or Saccharomyces cerevisiae, resulted in preferential germ tube segment staining of C. albicans. A dithiothreitol extract of mycelial-phase C. albicans organisms blocked staining of the germ tube segment, but a dithiothreitol extract of yeast-phase organisms did not. When dithiothreitol extracts from both phases were reacted against yeast-absorbed reference sera in tandem crossed and crossed line immunoelectrophoresis, a cross-reacting arc and several arcs unique to the mycelial-phase extract were noted. Immunofluorescent staining tests were performed, using appropriately absorbed sera from patients with candidiasis to stain a laboratory strain of C. albicans. Human tissue slices infected with C. albicans were used as targets for appropriately absorbed rabbit antisera. These human data indicated that antigens preferentially expressed on the germ tube in vitro were also expressed on filamentous structures of the fungus in infected human tissues. In vitro and in vivo, the invasive mycelial phase of C. albicans expresses certain antigens that are highly concentrated on the germ tube. Images PMID:6376363

  14. Evolution of germ-line signals that regulate growth and aging in nematodes

    PubMed Central

    Patel, Mavji N.; Knight, Christopher G.; Karageorgi, Constantina; Leroi, Armand M.

    2002-01-01

    We show that a signal from the germ line represses growth in the nematode Caenorhabditis elegans. Laser-microbeam ablation of cells that give rise to the germ line causes adults to become giant. Ablation of these cells in self-sterile mutant worms also causes gigantism, suggesting that the germ line represses growth because it is the source of a growth-antagonizing signal rather than because of a sink of resources required for reproduction. The C. elegans germ line also emits a signal that represses longevity. This longevity-repressing signal requires the activity of DAF-16, a forkhead/winged-helix transcription factor, but we find that that the growth-repressing signal does not. The growth-repressing signal also does not require the activity of DBL-1, a transforming growth factor ?-related protein that promotes growth in worms. By ablating the germ-line precursors of other species of free-living nematodes, we also found that both the growth-repressing and longevity-repressing signals are evolutionarily variable. Some species have both signals; others have just one or the other. We suggest that variation in germ-line signaling contributes to body size and life-history diversity in the nematodes. PMID:11805331

  15. Morphology and function of maturation ameloblasts in kitten tooth germs.

    PubMed

    Sasaki, T

    1984-03-01

    In order to clarify the morphology and function of maturation ameloblasts, kitten tooth germs were examined using an ultrastructural tracer technique. Kitten maturation ameloblasts were divided into two cell types: a ruffle-ended type showing plasma membrane infoldings and invaginations at the distal cell surface and a smooth-ended type showing a non-invaginated, smooth distal cell surface. Both ameloblasts possessed two sets of junctional complexes at their proximal and distal ends. In either type of cell, intravenously injected horseradish peroxidase penetrated from the vascular region into the developing enamel surface through both the proximal and distal junctional complexes, although the tight junction compartment inhibited horseradish peroxidase permeation. Ruffle-ended ameloblasts further incorporated peroxidase from the distal cell surface into the cytoplasm by means of membrane invaginations and coated vesicles. Smooth-ended ameloblasts showed little intracellular peroxidase incorporation. These results show clearly that resorptive and non-resorptive maturation ameloblasts exist in kitten enamel organ and that the two cell types correspond to ruffle-ended and smooth-ended maturation ameloblasts in rat incisors. PMID:6325377

  16. Morphology and function of maturation ameloblasts in kitten tooth germs.

    PubMed Central

    Sasaki, T

    1984-01-01

    In order to clarify the morphology and function of maturation ameloblasts, kitten tooth germs were examined using an ultrastructural tracer technique. Kitten maturation ameloblasts were divided into two cell types: a ruffle-ended type showing plasma membrane infoldings and invaginations at the distal cell surface and a smooth-ended type showing a non-invaginated, smooth distal cell surface. Both ameloblasts possessed two sets of junctional complexes at their proximal and distal ends. In either type of cell, intravenously injected horseradish peroxidase penetrated from the vascular region into the developing enamel surface through both the proximal and distal junctional complexes, although the tight junction compartment inhibited horseradish peroxidase permeation. Ruffle-ended ameloblasts further incorporated peroxidase from the distal cell surface into the cytoplasm by means of membrane invaginations and coated vesicles. Smooth-ended ameloblasts showed little intracellular peroxidase incorporation. These results show clearly that resorptive and non-resorptive maturation ameloblasts exist in kitten enamel organ and that the two cell types correspond to ruffle-ended and smooth-ended maturation ameloblasts in rat incisors. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Figs. 5-7 Fig. 8 Figs. 9-10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 PMID:6325377

  17. The quaternary structure of wheat-germ aspartate transcarbamoylase.

    PubMed Central

    Yon, R J; Grayson, J E; Chawda, A; Butterworth, P J

    1982-01-01

    1. The molecular mass of aspartate transcarbamoylase purified from wheat germ was found to be 101kDa by sucrose-density-gradient centrifugation, 103kDa by gel-filtration chromatography and 108kDa by polyacrylamide-gel electrophoresis. A mean value of 104 +/- 11kDa was obtained by pooling several replicate results from each method. 2. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate indicated a single size of polypeptide chain of mean molecular mass 37 +/- 4kDa. The ratio of the mean molecular masses of the active and denatured enzymes is 2.8.3. When the active enzyme was covalently cross-linked at a low protein concentration by dimethyl suberimidate, and then examined electrophoretically under denaturing conditions, three size species were observed to predominate, of apparent molecular masses 36, 77 and 106kDa respectively. 4. These results indicate that the intact, fully regulatory enzyme is a simple trimer, slightly larger than the trimeric "catalytic subunit' of the aspartate transcarbamoylase from Escherichia coli [Weber (1968) Nature (London) 218, 1116-1118]. The prevalence of trimeric structures amongst carbamoyl-transferase enzymes is discussed. Images Fig. 2. PMID:7115295

  18. Pathogen germs response to low-dose radiation — medical approach

    NASA Astrophysics Data System (ADS)

    Poiata, A.; Focea, R.; Creanga, D.

    2012-04-01

    The side effects of radiation therapy in the case of microbial loading of irradiated organs was considered as phenomenological basis of the experiment carried out on Staphylococcus aureus (ATCC germ) exposed to low X-ray doses. The inoculum was prepared in a liquid culture medium with standard composition, the volumes of 3 ml identical samples (in sterile glass tubes) being irradiated in hospital conditions. Five experimental variants were developed corresponding to irradiation time durations between 25 and 100 minutes. The spectro-colorimetric assay was accomplished at 560 nm and 420 nm, the resulting average values (for three repetitions) being analyzed from the viewpoint of cell density in the irradiated variants compared to control ones. The resistance to antibiotics of the irradiated bacteria was tested on agarized cultures against five antibiotic molecules (ampicillin, cloramphenicol, tetracycline, tobramicin and ofloxacin) by assessing the diameter of inhibition growth areas in each case. The increase of the inhibition area diameter with up to 15% (in the case of tetracycline) was noticed for the lowest irradiation time for all five antibiotics, which is suggesting a weakening of the bacteria resistance to the pharmaceutical agents following the X-ray treatment. This was concordant with the results of the spectro-colorimetric assay of the cell density within the directly irradiated bacteria cultures. The main issue of this study is concerning the optimization of the radiotherapy protocol in patients with potential microbial loading.

  19. Hematopoietic activity in putative mouse primordial germ cell populations.

    PubMed

    Scaldaferri, Maria Lucia; Klinger, Francesca Gioia; Farini, Donatella; Di Carlo, Anna; Carsetti, Rita; Giorda, Ezio; De Felici, Massimo

    2015-05-01

    In the present paper, starting from the observation of heterogeneous expression of the GOF-18?PE-GFP Pou5f1 (Oct3/4) transgene in putative mouse PGC populations settled in the aorta-gonad-mesonephros (AGM) region, we identified various OCT3/4 positive populations showing distinct expression of PGC markers (BLIMP-1, AP, TG-1, STELLA) and co-expressing several proteins (CD-34, CD-41, FLK-1) and genes (Brachyury, Hox-B4, Scl/Tal-1 and Gata-2) of hematopoietic precursors. Moreover, we found that Oct3/4-GFP(weak) CD-34(weak/high) cells possess robust hematopoietic colony forming activity (CFU) in vitro. These data indicate that the cell population usually considered PGCs moving toward the gonadal ridges encompasses a subset of cells co-expressing several germ cell and hematopoietic markers and possessing hematopoietic activity. These results are discussed within of the current model of germline segregation. PMID:25684074

  20. Sidestream tobacco smoke is a male germ cell mutagen.

    PubMed

    Marchetti, Francesco; Rowan-Carroll, Andrea; Williams, Andrew; Polyzos, Aris; Berndt-Weis, M Lynn; Yauk, Carole L

    2011-08-01

    Active cigarette smoking increases oxidative damage, DNA adducts, DNA strand breaks, chromosomal aberrations, and heritable mutations in sperm. However, little is known regarding the effects of second-hand smoke on the male germ line. We show here that short-term exposure to mainstream tobacco smoke or sidestream tobacco smoke (STS), the main component of second-hand smoke, induces mutations at an expanded simple tandem repeat locus (Ms6-hm) in mouse sperm. We further show that the response to STS is not linear and that, for both mainstream tobacco smoke and STS, doses that induced significant increases in expanded simple tandem repeat mutations in sperm did not increase the frequencies of micronucleated reticulocytes and erythrocytes in the bone marrow and blood of exposed mice. These data show that passive exposure to cigarette smoke can cause tandem repeat mutations in sperm under conditions that may not induce genetic damage in somatic cells. Although the relationship between noncoding tandem repeat instability and mutations in functional regions of the genome is unclear, our data suggest that paternal exposure to second-hand smoke may have reproductive consequences that go beyond the passive smoker. PMID:21768363

  1. Treatment of disseminated germ cell tumours of the testis.

    PubMed

    Athanassiou, A; Pectasides, D; Bafaloukos, D; Barbounis, V; Dimitriadis, M; Christodoulou, K

    1989-05-01

    Between 1979 and 1987 64 men with non-seminomatous germ cell tumours of the testis were treated with chemotherapy. Nearly half of these patients had large volume disease. The most frequently used combinations were VAB-6 and POMB/ACE. Chemotherapy lasted 3.9 months for small volume disease and 5.5 months for large volume disease. Seven patients (11%) underwent resection of residual masses; viable malignancy was found in only 1 of these. Relapse occurred in 6 complete responders, 3 of whom were salvaged with further chemotherapy. Fifty-three patients are presently alive and have received no treatment for periods of 5 to 86 months. Life table analysis forecasts a survival of 81%. Adverse prognostic factors have been recognised and include high initial serum concentrations of beta-human chorionic gonadotrophin (beta-HCG) and alpha fetoprotein (AFP), large volume disease and prior irradiation. Although the survival time of patients with advanced disease has improved in recent years, it remains considerably below that of patients who present with less advanced disease. Such patients should be treated aggressively from the outset in order to obtain maximum benefit from chemotherapy. Selected cases also require adjunctive surgery. PMID:2471573

  2. Age-related biological features of germ cell tumors.

    PubMed

    Collinson, Kate; Murray, Matthew J; Orsi, Nicolas M; Cummings, Michele; Shipley, Janet; Joffe, Johnathan K; Coleman, Nicholas; Stark, Daniel

    2014-03-01

    Germ cell tumors (GCTs) are rare but clinically and pathologically diverse tumors that occur in an extensive range of age groups, from children to older adults and which include both seminomatous and nonseminomatous tumors. Current clinical management for both male and female teenagers and young adults (TYAs) with GCTs remains inconsistent, alternating between pediatric and adult multidisciplinary oncology teams, based on locally defined age cutoffs. Therefore, we reviewed available literature to determine the biological similarities and differences between GCTs in young children (0-12 years), TYAs (13-24 years), and older adults (>24 years). GCTs arising in pediatric and adult populations in general showed marked molecular biological differences within identical histological subtypes, whereas there was a distinct paucity of available data for GCTs in the TYA population. These findings highlight that clinical management based simply on chronological age may be inappropriate for TYA and suggests that the optimal future management of GCTs should consider specific molecular biological factors in addition to clinical parameters in the context of patient-specific age group rather than medical specialty. PMID:24311530

  3. A pair-rule gene circuit defines segments sequentially in the short-germ insect Tribolium castaneum.

    PubMed

    Choe, Chong Pyo; Miller, Sherry C; Brown, Susan J

    2006-04-25

    In Drosophila, a hierarchy of maternal, gap, pair-rule, and segment polarity gene interactions regulates virtually simultaneous blastoderm segmentation. For the last decade, studies have focused on revealing the extent to which Drosophila segmentation mechanisms are conserved in other arthropods where segments are added sequentially from anterior to posterior in a cellular environment. Despite our increased knowledge of individual segmentation genes, details of their interactions in non-Drosophilid insects are not well understood. We analyzed the Tribolium orthologs of Drosophila pair-rule genes, which display pair-rule expression patterns. Tribolium castaneum paired (Tc-prd) and sloppy-paired (Tc-slp) genes produced pair-rule phenotypes when their transcripts were severely reduced by RNA interference. In contrast, similar analysis of T. castaneum even-skipped (Tc-eve), runt (Tc-run), or odd-skipped (Tc-odd) genes produced severely truncated, almost completely asegmental phenotypes. Analysis of interactions between pair-rule components revealed that Tc-eve, Tc-run, and Tc-odd form a three-gene circuit to regulate one another as well as their downstream targets, Tc-prd and Tc-slp. The complement of primary pair-rule genes in Tribolium differs from Drosophila in that it includes Tc-odd but not Tc-hairy. This gene circuit defines segments sequentially in double segment periodicity. Furthermore, this single mechanism functions in the early blastoderm stage and subsequently during germ-band elongation. The periodicity of the Tribolium pair-rule gene interactions reveals components of the genetic hierarchy that are regulated in a repetitive circuit or clock-like mechanism. This pair-rule gene circuit provides insight into short-germ segmentation in Tribolium that may be more generally applicable to segmentation in other arthropods. PMID:16611732

  4. 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. PMID:22190706

  5. Genetic Alteration of the c-myc Protooncogene (MYC) in Human Primary Breast Carcinomas

    Microsoft Academic Search

    Chantal Escot; Charles Theillet; Rosette Lidereau; Frederique Spyratos; Marie-Helene Champeme; Jean Gest; Robert Callahan

    1986-01-01

    We have studied the genomic organization of the c-myc locus (MYC) from 121 human primary breast carcinomas. Two types of alterations were observed: (i) the c-myc protooncogene appeared to be amplified 2- to 15-fold in 38 (32%) of the carcinoma DNAs and (ii) a non-germ-line c-myc-related fragment of variable size was detected in 5 primary breast carcinoma DNAs. With three

  6. European Consensus Conference on Diagnosis and Treatment of Germ Cell Cancer: A Report of the Second Meeting of the European Germ Cell Cancer Consensus group (EGCCCG): Part I

    Microsoft Academic Search

    Susanne Krege; Jörg Beyer; Rainer Souchon; Peter Albers; Walter Albrecht; Ferran Algaba; Michael Bamberg; István Bodrogi; Carsten Bokemeyer; Eva Cavallin-Ståhl; Johannes Classen; Christoph Clemm; Gabriella Cohn-Cedermark; Stéphane Culine; Gedske Daugaard; Pieter H. M. De Mulder; Maria De Santis; Maike de Wit; Ronald de Wit; Hans Günter Derigs; Klaus-Peter Dieckmann; Annette Dieing; Jean-Pierre Droz; Martin Fenner; Karim Fizazi; Aude Flechon; Sophie D. Fosså; Xavier Garcia del Muro; Thomas Gauler; Lajos Geczi; Arthur Gerl; Jose Ramon Germa-Lluch; Silke Gillessen; Jörg T. Hartmann; Michael Hartmann; Axel Heidenreich; Wolfgang Hoeltl; Alan Horwich; Robert Huddart; Michael Jewett; Johnathan Joffe; William G. Jones; László Kisbenedek; Olbjørn Klepp; Sabine Kliesch; Kai Uwe Koehrmann; Christian Kollmannsberger; Markus Kuczyk; Pilar Laguna; Oscar Leiva Galvis; Volker Loy; Malcolm D. Mason; Graham M. Mead; Rolf Mueller; Craig Nichols; Nicola Nicolai; Tim Oliver; Dalibor Ondrus; Gosse O. N. Oosterhof; Luis Paz Ares; Giorgio Pizzocaro; Jörg Pont; Tobias Pottek; Tom Powles; Oliver Rick; Giovanni Rosti; Roberto Salvioni; Jutta Scheiderbauer; Hans-Ulrich Schmelz; Heinz Schmidberger; Hans-Joachim Schmoll; Mark Schrader; Felix Sedlmayer; Niels E. Skakkebaek; Aslam Sohaib; Sergei Tjulandin; Padraig Warde; Stefan Weinknecht; Lothar Weissbach; Christian Wittekind; Eva Winter; Lori Wood; Hans von der Maase

    2008-01-01

    ObjectivesThe first consensus report presented by the European Germ Cell Cancer Consensus Group (EGCCCG) in the year 2004 has found widespread approval by many colleagues throughout the world. In November 2006, the group met a second time under the auspices of the Department of Urology of the Amsterdam Medical Center, Amsterdam, The Netherlands.

  7. European Consensus Conference on Diagnosis and Treatment of Germ Cell Cancer: A Report of the Second Meeting of the European Germ Cell Cancer Consensus Group (EGCCCG): Part II

    Microsoft Academic Search

    Susanne Krege; Jörg Beyer; Rainer Souchon; Peter Albers; Walter Albrecht; Ferran Algaba; Michael Bamberg; István Bodrogi; Carsten Bokemeyer; Eva Cavallin-Ståhl; Johannes Classen; Christoph Clemm; Gabriella Cohn-Cedermark; Stéphane Culine; Gedske Daugaard; Pieter H. M. De Mulder; Maria De Santis; Maike de Wit; Ronald de Wit; Hans Günter Derigs; Klaus-Peter Dieckmann; Annette Dieing; Jean-Pierre Droz; Martin Fenner; Karim Fizazi; Aude Flechon; Sophie D. Fosså; Xavier Garcia del Muro; Thomas Gauler; Lajos Geczi; Arthur Gerl; Jose Ramon Germa-Lluch; Silke Gillessen; Jörg T. Hartmann; Michael Hartmann; Axel Heidenreich; Wolfgang Hoeltl; Alan Horwich; Robert Huddart; Michael Jewett; Johnathan Joffe; William G. Jones; László Kisbenedek; Olbjørn Klepp; Sabine Kliesch; Kai Uwe Koehrmann; Christian Kollmannsberger; Markus Kuczyk; Pilar Laguna; Oscar Leiva Galvis; Volker Loy; Malcolm D. Mason; Graham M. Mead; Rolf Mueller; Craig Nichols; Nicola Nicolai; Tim Oliver; Dalibor Ondrus; Gosse O. N. Oosterhof; Luis Paz-Ares; Giorgio Pizzocaro; Jörg Pont; Tobias Pottek; Tom Powles; Oliver Rick; Giovanni Rosti; Roberto Salvioni; Jutta Scheiderbauer; Hans-Ulrich Schmelz; Heinz Schmidberger; Hans-Joachim Schmoll; Mark Schrader; Felix Sedlmayer; Niels E. Skakkebaek; Aslam Sohaib; Sergei Tjulandin; Padraig Warde; Stefan Weinknecht; Lothar Weissbach; Christian Wittekind; Eva Winter; Lori Wood; Hans von der Maase

    2008-01-01

    ObjectivesThe first consensus report that had been presented by the European Germ Cell Cancer Consensus Group (EGCCCG) in 2004 has found widespread approval by many colleagues throughout the world. In November 2006, the group met a second time under the auspices of the Department of Urology of the Amsterdam Medical Center, The Netherlands.

  8. Uredospore germination and germ tube penetration of Puccinia striiformis in seedling leaves of resistant and susceptible wheat varieties

    Microsoft Academic Search

    R. W. Stubbs; J. M. Plotnikova

    1972-01-01

    Differences were observed in spore germination and germ tube penetration of race 60 ofPuccinia striiformis on some wheat varieties. Of the five wheat varieties investigatedTriticum spelta var.album was the most resistant, strongly inhibiting spore germination and retarding germ tube penetration. On the hexaploid wheat varieties the germ tube penetrated through the stomata, whereas on the tetraploid varieties it did so

  9. Anti-Oxidant and Anti-Adipogenic Effects of Ethanol Extracts from Wheat Germ and Wheat Germ Fermented with Aspergillus oryzae.

    PubMed

    Park, Euna; Kim, Hae Ok; Kim, Gyo-Nam; Song, Ji-Hye

    2015-03-01

    Most of the wheat germ in cereal grains is removed during the milling process. Various physiological effects have been reported for bioactive substances in wheat germ such as phenolic acids and flavonoids. In this study, the anti-oxidant and anti-adipogenic effects of ethanol extracts from wheat germ (WGE) and wheat germ fermented with Aspergillus oryzae (F-WGE) were investigated in HepG2 and 3T3-L1 cells. The anti-oxidant activity of F-WGE was demonstrated by a dose-dependent increase in the enhanced scavenging capacity of hydroxyl radicals and Cu(2+)-chelating activity compared to WGE. WGE and F-WGE treatment at doses between 10 and 400 ?g/mL did not affect the viability of HepG2 and 3T3-L1 cells. Intracellular ROS levels from Cu(2+)-induced oxidative stress were significantly decreased by F-WGE treatment in HepG2 cells compared to WGE. Lipid accumulation was increased in 3T3-L1 adipocytes by 100 ?M Fe(2+) treatment, but the accumulation was strongly inhibited by 100 ?g/mL of WGE and F-WGE treatment. These results suggest that changes in bioactive substances during the fermentation of wheat germ can potentiate scavenging activities against transition metal-induced oxidative stress and lipid accumulation in 3T3-L1 adipocytes. Therefore, we propose that F-WGE is a novel food materials and provided scientific evidences for its efficacy in the development of functional foods. PMID:25866747

  10. 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

  11. Endogenous DNA damage and testicular germ cell tumors

    PubMed Central

    Cook, Michael B.; Sigurdson, Alice J.; Jones, Irene M.; Thomas, Cynthia B.; Graubard, Barry I.; Korde, Larissa; Greene, Mark H.; McGlynn, Katherine A.

    2008-01-01

    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 levels of net endogenous DNA damage. To test our hypothesis, we conducted a case-case analysis of 51 seminoma and 61 nonseminoma patients using data and specimens from the Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort. 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 (OR50th percentile=3.31, 95%CI: 1.00, 10.98; OR75th percentile=3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR50th percentile=2.27, 95%CI: 0.75, 6.87; OR75th 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 net endogenous 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. PMID:18657195

  12. Novel somatic and germline mutations in intracranial germ cell tumours.

    PubMed

    Wang, Linghua; Yamaguchi, Shigeru; Burstein, Matthew D; Terashima, Keita; Chang, Kyle; Ng, Ho-Keung; Nakamura, Hideo; He, Zongxiao; Doddapaneni, Harshavardhan; Lewis, Lora; Wang, Mark; Suzuki, Tomonari; Nishikawa, Ryo; Natsume, Atsushi; Terasaka, Shunsuke; Dauser, Robert; Whitehead, William; Adekunle, Adesina; Sun, Jiayi; Qiao, Yi; Marth, Gábor; Muzny, Donna M; Gibbs, Richard A; Leal, Suzanne M; Wheeler, David A; Lau, Ching C

    2014-07-10

    Intracranial germ cell tumours (IGCTs) are a group of rare heterogeneous brain tumours that are clinically and histologically similar to the more common gonadal GCTs. IGCTs show great variation in their geographical and gender distribution, histological composition and treatment outcomes. The incidence of IGCTs is historically five- to eightfold greater in Japan and other East Asian countries than in Western countries, with peak incidence near the time of puberty. About half of the tumours are located in the pineal region. The male-to-female incidence ratio is approximately 3-4:1 overall, but is even higher for tumours located in the pineal region. Owing to the scarcity of tumour specimens available for research, little is currently known about this rare disease. Here we report the analysis of 62 cases by next-generation sequencing, single nucleotide polymorphism array and expression array. We find the KIT/RAS signalling pathway frequently mutated in more than 50% of IGCTs, including novel recurrent somatic mutations in KIT, its downstream mediators KRAS and NRAS, and its negative regulator CBL. Novel somatic alterations in the AKT/mTOR pathway included copy number gains of the AKT1 locus at 14q32.33 in 19% of patients, with corresponding upregulation of AKT1 expression. We identified loss-of-function mutations in BCORL1, a transcriptional co-repressor and tumour suppressor. We report significant enrichment of novel and rare germline variants in JMJD1C, which codes for a histone demethylase and is a coactivator of the androgen receptor, among Japanese IGCT patients. This study establishes a molecular foundation for understanding the biology of IGCTs and suggests potentially promising therapeutic strategies focusing on the inhibition of KIT/RAS activation and the AKT1/mTOR pathway. PMID:24896186

  13. 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.

  14. 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. PMID:25634576

  15. Expression pattern of clinically relevant markers in paediatric germ cell- and sex-cord stromal tumours is similar to adult testicular tumours.

    PubMed

    Mosbech, Christiane Hammershaimb; Svingen, Terje; Nielsen, John Erik; Toft, Birgitte Groenkaer; Rechnitzer, Catherine; Petersen, Bodil Laub; Rajpert-De Meyts, Ewa; Hoei-Hansen, Christina Engel

    2014-11-01

    Paediatric germ cell tumours (GCTs) are rare and account for less than 3 % of childhood cancers. Like adult GCTs, they probably originate from primordial germ cells, but the pattern of histopathological types is different, and they occur predominantly in extragonadal sites along the body midline. Because they are rare, histology of paediatric GCTs is poorly documented, and it remains unclear to what extent they differ from adult GCTs. We have analysed 35 paediatric germ cell tumours and 5 gonadal sex-cord stromal tumours from prepubertal patients aged 0-15 years, to gain further knowledge, elaborate on clinical-pathological associations and better understand their developmental divergence. The tumours were screened for expression of stemness-related factors (OCT4, AP-2?, SOX2), classical yolk sac tumours (YSTs; AFP, SALL4), GCTs (HCG, PLAP, PDPN/D2-40), as well as markers for sex-cord stromal tumour (PDPN, GATA4). All YSTs expressed AFP and SALL4, with GATA4 present in 13/14. The majority of teratomas expressed SOX2 and PDPN, whereas SALL4 was found in 8/13 immature teratomas. Adult seminoma markers AP-2?, OCT4, SALL4 and PDPN were all expressed in dysgerminoma. We further report a previously unrecognised pathogenetic relationship between AFP and SALL4 in YST in that different populations of YST cells express either SALL4 or AFP, which suggests variable differentiation status. We also show that AP-2? is expressed in the granulosa layer of ovarian follicles and weakly expressed in immature but not in mature granulosa cell tumours. Our findings indicate that the expression pattern of these antigens is similar between paediatric and adult GCTs, even though they develop along different developmental trajectories. PMID:25074678

  16. Mouse primordial germ cells produce cysts that partially fragment prior to meiosis

    PubMed Central

    Lei, Lei; Spradling, Allan C.

    2013-01-01

    Mammalian germ cells divide mitotically and form nests of associated cells just prior to entering meiosis. At least some nests contain germline cysts that arise by synchronous, incomplete mitotic divisions, but others may form by aggregation. To systematically investigate early murine germ cell development, we lineage marked the progeny of individual, newly arrived primordial germ cells in the E10.5 gonad. All the marked germ cells initially develop into clones containing two, four or eight cells, indicating cyst formation. Surprisingly, growing cysts in both sexes partially fragment into smaller cysts prior to completion and associate with cysts from unrelated progenitors. At the time divisions cease, female clones comprise five cysts on average that eventually give rise to about six primordial follicles. Male cyst cells break apart and probably become spermatogonial stem cells. Thus, cysts are invariant units of mouse germ cell development and cyst fragmentation provides insight into the amplification of spermatogonial stem cells and the origin of primordial follicles. PMID:23578925

  17. Vasa Identifies Germ Cells and Critical Stages of Oogenesis in the Asian Seabass

    PubMed Central

    Xu, Hongyan; Lim, Menghuat; Dwarakanath, Manali; Hong, Yunhan

    2014-01-01

    Germ cells produce sperm and eggs for reproduction and fertility. The Asian seabass (Lates calcarifer), a protandrous marine fish, undergoes male-female sex reversal and thus offers an excellent model to study the role of germ cells in sex differentiation and sex reversal. Here we report the cloning and expression of vasa as a first germ cell marker in this organism. A 2241-bp cDNA was cloned by PCR using degenerate primers of conserved sequences and gene-specific primers. This cDNA contains a polyadenylation signal and a full open reading frame for 645 amino acid residues, which was designated as Lcvasa for the seabass vasa, as its predicted protein is homologous to Vasa proteins. The Lcvasa RNA is maternally supplied and specific to gonads in adulthood. By chromogenic and fluorescent in situ hybridization we revealed germ cell-specific Lcvasa expression in both the testis and ovary. Importantly, Lcvasa shows dynamic patterns of temporospatial expression and subcellular distribution during gametogenesis. At different stages of oogenesis, for example, Lcvasa undergoes nuclear-cytoplasmic redistribution and becomes concentrated preferentially in the Balbiani body of stage-II~III oocytes. Thus, the vasa RNA identifies both female and male germ cells in the Asian seabass, and its expression and distribution delineate critical stages of gametogenesis. PMID:24550690

  18. Identification of a novel male germ cell-specific gene TESF-1 in mice

    SciTech Connect

    Fan Jun [Department of Biological Sciences, Marshall University, Huntington, WV (United States); Graham, Matthew [Department of Biological Sciences, Marshall University, Huntington, WV (United States); Akabane, Hiroto [Department of Biological Sciences, Marshall University, Huntington, WV (United States); Richardson, Laura L. [Department of Anatomy and Pathology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV (United States); Zhu Guozhang [Department of Biological Sciences, Marshall University, Huntington, WV (United States)]. E-mail: zhu4@marshall.edu

    2006-02-03

    Mammalian spermatogenesis is precisely regulated by many germ cell-specific factors. In search for such a germ cell-specific factor, we have identified a novel mouse gene testis-specific factor 1 (TESF-1). Messenger RNA of TESF-1 was found only in the testis and its expression appeared to be regulated in a developmental manner. Further analysis demonstrated that the expression of TESF-1 was specifically in male germ cells, supported by the observation that we were not able to detect the TESF-1 mRNA from at/at homozygous mutant testes, which lack germ cells. The deduced amino acid sequence of TESF-1 contains a leucine-zipper motif, a potential nuclear localization signal, and two cAMP- and cGMP-dependent protein kinase phosphorylation sites. The green fluorescent protein (GFP)-tagged TESF-1 fusion protein was expressed in COS-7 cells and localized primarily in the nucleus. Taken together, these results indicate that TESF-1 is a novel male germ cell-specific gene, and its protein product may function as a nuclear factor involved in the regulation of spermatogenesis.

  19. Treatment of GABA from Fermented Rice Germ Ameliorates Caffeine-Induced Sleep Disturbance in Mice

    PubMed Central

    Mabunga, Darine Froy N.; Gonzales, Edson Luck T.; Kim, Hee Jin; Choung, Se Young

    2015-01-01

    ?-Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is involved in sleep physiology. Caffeine is widely used psychoactive substance known to induce wakefulness and insomnia to its consumers. This study was performed to examine whether GABA extracts from fermented rice germ ameliorates caffeine-induced sleep disturbance in mice, without affecting spontaneous locomotor activity and motor coordination. Indeed, caffeine (10 mg/kg, i.p.) delayed sleep onset and reduced sleep duration of mice. Conversely, rice germ ferment extracts-GABA treatment (10, 30, or 100 mg/kg, p.o.), especially at 100 mg/kg, normalized the sleep disturbance induced by caffeine. In locomotor tests, rice germ ferment extracts-GABA slightly but not significantly reduced the caffeine-induced increase in locomotor activity without affecting motor coordination. Additionally, rice germ ferment extracts-GABA per se did not affect the spontaneous locomotor activity and motor coordination of mice. In conclusion, rice germ ferment extracts-GABA supplementation can counter the sleep disturbance induced by caffeine, without affecting the general locomotor activities of mice. PMID:25995826

  20. Licensing of Primordial Germ Cells for Gametogenesis Depends on Genital Ridge Signaling

    PubMed Central

    Hu, Yueh-Chiang; Nicholls, Peter K.; Soh, Y. Q. Shirleen; Daniele, Joseph R.; Junker, Jan Philipp; van Oudenaarden, Alexander; Page, David C.

    2015-01-01

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO) mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge. PMID:25739037

  1. Sex determination signals control ovo-B transcription in Drosophila melanogaster germ cells.

    PubMed Central

    Andrews, Justen; Oliver, Brian

    2002-01-01

    Nonautonomous inductive signals from the soma and autonomous signals due to a 2X karyotype determine the sex of Drosophila melanogaster germ cells. These two signals have partially overlapping influences on downstream sex determination genes. The upstream OVO-B transcription factor is required for the viability of 2X germ cells, regardless of sexual identity, and for female germline sexual identity. The influence of inductive and autonomous signals on ovo expression has been controversial. We show that ovo-B is strongly expressed in the 2X germ cells in either a male or a female soma. This indicates that a 2X karyotype controls ovo-B expression in the absence of inductive signals from the female soma. However, we also show that female inductive signals positively regulate ovo-B transcription in the 1X germ cells that do not require ovo-B function. Genetic analysis clearly indicates that inductive signals from the soma are not required for ovo-B function in 2X germ cells. Thus, while somatic inductive signals and chromosome karyotype have overlapping regulatory influences, a 2X karyotype is a critical germline autonomous determinant of ovo-B function in the germline. PMID:11861560

  2. Female mice lack adult germ-line stem cells but sustain oogenesis using stable primordial follicles

    PubMed Central

    Lei, Lei; Spradling, Allan C.

    2013-01-01

    Whether or not mammalian females generate new oocytes during adulthood from germ-line stem cells to sustain the ovarian follicle pool has recently generated controversy. We used a sensitive lineage-labeling system to determine whether stem cells are needed in female adult mice to compensate for follicular losses and to directly identify active germ-line stem cells. Primordial follicles generated during fetal life are highly stable, with a half-life during adulthood of 10 mo, and thus are sufficient to sustain adult oogenesis without a source of renewal. Moreover, in normal mice or following germ-cell depletion with Busulfan, only stable, single oocytes are lineage-labeled, rather than cell clusters indicative of new oocyte formation. Even one germ-line stem cell division per 2 wk would have been detected by our method, based on the kinetics of fetal follicle formation. Thus, adult female mice neither require nor contain active germ-line stem cells or produce new oocytes in vivo. PMID:23630252

  3. Caste determination in a polyembryonic wasp involves inheritance of germ cells

    PubMed Central

    Donnell, David M.; Corley, Laura S.; Chen, Gang; Strand, Michael R.

    2004-01-01

    Social insects are characterized by the development of castes in which some colony members reproduce whereas others function as altruistic helpers. The conditional switch controlling caste formation usually involves environmental stimuli that act on processes that regulate development of individuals. Unlike other social species, embryos of polyembryonic wasps develop clonally to produce large numbers of genetically identical offspring and two morphologically distinct castes. All embryos in a clone exist in an identical environment, the host, yet develop into either reproductive larvae that mature into adult wasps or soldier larvae whose function is defense. Here, we report that caste determination in Copidosoma floridanum involves inheritance of germ cells. Expression of a C. floridanum homolog (Cf-vas) of the germ cell marker Vasa indicated that the B4 blastomere in four cell-stage embryos is specified as a primordial germ cell. Vas expression later in development further indicated that embryos developing into reproductive larvae possess primordial germ cells whereas embryos developing into soldier larvae do not. Ablation of the B4 blastomere resulted in most broods containing only soldiers whereas ablation of other blastomeres produced broods containing both castes. These results indicate that soldier larvae are obligately sterile and reveal a previously unknown role for germ cells in caste formation. PMID:15226498

  4. Effects of luteinizing hormone treatment on oogenesis in ovarian germ cells of the chick (Gallus domesticus).

    PubMed

    González-Morán, Ma Genoveva

    2007-08-01

    The effect of the luteinizing hormone (LH) on the oogenesis of ovaries from newly-hatched chicks treated in vivo on days 13, 15, and 17 of embryonic development was analyzed. Changes in oogonial proliferation, meiotic prophase, degeneration of germ cells, and primordial follicular organization were determined. Results indicate that the total number of germ cells was not affected by the LH treatment, but significant differences existed in the number of oogonia and oocytes between the ovaries of control and LH-treated chicks. LH treatment increased the percentage of oocytes and diminished the percentage of oogonia. The mitotic activity of oogonia and degeneration of germ cells decreased, but the number of follicles during development increased in LH-treated ovaries. These findings suggest that LH treatment might trigger a cascade of endocrine events, resulting in inhibition of oogonial proliferation and induction of the meiotic prophase and follicle formation. PMID:16769195

  5. Inhibitory phosphorylation of separase is essential for genome stability and viability of murine embryonic germ cells.

    PubMed

    Huang, Xingxu; Andreu-Vieyra, Claudia V; York, J Philippe; Hatcher, Rashieda; Lu, Tao; Matzuk, Martin M; Zhang, Pumin

    2008-01-01

    Activity of separase, a cysteine protease that cleaves sister chromatid cohesin at the onset of anaphase, is tightly regulated to ensure faithful chromosome segregation and genome stability. Two mechanisms negatively regulate separase: inhibition by securin and phosphorylation on serine 1121. To gauge the physiological significance of the inhibitory phosphorylation, we created a mouse strain in which Ser1121 was mutated to Ala (S1121A). Here we report that this S1121A point mutation causes infertility in mice. We show that germ cells in the mutants are depleted during development. We further demonstrate that S1121A causes chromosome misalignment during proliferation of the postmigratory primordial germ cells, resulting in mitotic arrest, aneuploidy, and eventual cell death. Our results indicate that inhibitory phosphorylation of separase plays a critical role in the maintenance of sister chromatid cohesion and genome stability in proliferating postmigratory primordial germ cells. PMID:18232736

  6. 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.

  7. The dnd RNA Identifies Germ Cell Origin and Migration in Olive Flounder (Paralichthys olivaceus)

    PubMed Central

    Wang, Xueying; Liu, Qinghua; Xiao, Yongshuang; Yang, Yang; Wang, Yanfeng; Song, Zongcheng; You, Feng; An, Hao; Xiao, Zhizhong; Xu, Shihong; Ma, Daoyuan; Li, Jun

    2015-01-01

    The present study obtained a germ cell-specific marker dead end (dnd) in olive flounder (Paralichthys olivaceus) named Podnd. The tissue-specific expressions of Podnd transcripts were present in testis and ovary but were not detectable in other somatic tissues detected. SISH showed that Podnd expressed only in germ cells at different developmental stages but not in surrounding somatic cells. The expression of Podnd during embryonic development at 16 different stages revealed that the relative expression of Podnd transcript fluctuated at a high level in the cleavage stages, gradually decreased through subsequent development, and reached the lowest at late gastrula stage till it was nearly undetectable. The Podnd transcripts localization and migration were similar to zebrafish. Further research on the specification migration mechanism of PGCs and the role of germ cell during gonadal development in olive flounder would improve our understanding of germline development.

  8. Functional lacrimal gland regeneration by transplantation of a bioengineered organ germ

    PubMed Central

    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

  9. 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 variation of the mechanism regulating the mitochondrial bottleneck in all metazoans. PMID:22140544

  10. 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...

  11. 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

  12. A role for Dazl in commitment to gametogenic fate in embryonic germ cells of C57BL/6 mice

    E-print Network

    Lin, Yanfeng, Ph. D. Massachusetts Institute of Technology

    2005-01-01

    Germ cells can be defined as the cells that undergo the terminal differentiating process of meiosis. In mice, as XX germ cells enter meiosis around Embryonic days 13.5-14.5 (E13.5-E14.5), they form meiotic figures and ...

  13. Identification of Grandchildless Loci Whose Products Are Required for Normal Germ-Line Development in the Nematode Caenorhabditis Elegans

    PubMed Central

    Capowski, E. E.; Martin, P.; Garvin, C.; Strome, S.

    1991-01-01

    To identify genes that encode maternal components required for development of the germ line in the nematode Caenorhabditis elegans, we have screened for mutations that confer a maternal-effect sterile or ``grandchildless'' phenotype: homozygous mutant hermaphrodites produced by heterozygous mothers are themselves fertile, but produce sterile progeny. Our screens have identified six loci, defined by 21 mutations. This paper presents genetic and phenotypic characterization of four of the loci. The majority of mutations, those in mes-2, mes-3 and mes-4, affect postembryonic germ-line development; the progeny of mutant mothers undergo apparently normal embryogenesis but develop into agametic adults with 10-1000-fold reductions in number of germ cells. In contrast, mutations in mes-1 cause defects in cytoplasmic partitioning during embryogenesis, and the resulting larvae lack germ-line progenitor cells. Mutations in all of the mes loci primarily affect the germ line, and none disrupt the structural integrity of germ granules. This is in contrast to grandchildless mutations in Drosophila melanogaster, all of which disrupt germ granules and affect abdominal as well as germ-line development. PMID:1783292

  14. LIN-35/Rb Causes Starvation-Induced Germ Cell Apoptosis via CED-9/Bcl2 Downregulation in Caenorhabditis elegans

    PubMed Central

    Láscarez-Lagunas, L. I.; Silva-García, C. G.; Dinkova, T. D.

    2014-01-01

    Apoptosis is an important mechanism for maintaining germ line health. In Caenorhabditis elegans, germ cell apoptosis occurs under normal conditions to sustain gonad homeostasis and oocyte quality. Under stress, germ cell apoptosis can be triggered via different pathways, including the following: (i) the CEP-1/p53 pathway, which induces germ cell apoptosis when animals are exposed to DNA damage; (ii) the mitogen-activated protein kinase kinase (MAPKK) pathway, which triggers germ cell apoptosis when animals are exposed to heat shock, oxidative stress, or osmotic stress; and (iii) an unknown mechanism that triggers germ cell apoptosis during starvation. Here, we address how starvation induces germ cell apoptosis. Using polysomal profiling, we found that starvation for 6 h reduces the translationally active ribosomes, which differentially affect the mRNAs of the core apoptotic machinery and some of its regulators. During starvation, lin-35/Rb mRNA increases its expression, resulting in the accumulation of this protein. As a consequence, LIN-35 downregulates the expression of the antiapoptotic gene ced-9/Bcl-2. We observed that the reduced translation of ced-9/Bcl-2 mRNA during food deprivation together with its downregulation drastically affects its protein accumulation. We propose that CED-9/Bcl-2 downregulation via LIN-35/Rb triggers germ cell apoptosis in C. elegans in response to starvation. PMID:24752899

  15. Two waves of de novo methylation during mouse germ cell development

    PubMed Central

    Molaro, Antoine; Falciatori, Ilaria; Hodges, Emily; Aravin, Alexei A.; Marran, Krista; Rafii, Shahin; McCombie, W. Richard; Smith, Andrew D.; Hannon, Gregory J.

    2014-01-01

    During development, mammalian germ cells reprogram their epigenomes via a genome-wide erasure and de novo rewriting of DNA methylation marks. We know little of how methylation patterns are specifically determined. The piRNA pathway is thought to target the bulk of retrotransposon methylation. Here we show that most retrotransposon sequences are modified by default de novo methylation. However, potentially active retrotransposon copies evade this initial wave, likely mimicking features of protein-coding genes. These elements remain transcriptionally active and become targets of piRNA-mediated methylation. Thus, we posit that these two waves play essential roles in resetting germ cell epigenomes at each generation. PMID:25030694

  16. Spontaneous pneumothorax following chemotherapy for metastatic germ cell tumor: a case report.

    PubMed

    Loutfi, Rania; Kattan, Joseph; Kikano, Toufic

    2004-01-01

    We report on a 30-year-old man with metastatic non seminomatous germ cell tumor of the left testicle to the abdomen and the lungs, who suddenly developed a bilateral spontaneous pneumothorax after the first course of salvage chemotherapy. Rapid destruction and lysis of lung nodules by chemotherapy seem to be the main mechanism of pneumothorax development. According to our case report and to the literature, the onset of acute dyspnea after chemotherapy for lung metastatic germ cell tumor should alert to the possibility of spontaneous pneumothorax. PMID:15884692

  17. Radical Resection of a Late-Relapsed Testicular Germ Cell Tumour: Hepatectomy, Cavotomy, and Thrombectomy

    PubMed Central

    Ní Leidhin, C.; Redmond, C. E.; Cahalane, A. M.; Heneghan, H. M.; Motyer, R.; Ryan, E. R.; Hoti, E.

    2014-01-01

    Up to 3.2% of patients with testicular germ cell tumours represent with late-relapsing disease. Aggressive surgical resection confers the greatest chance of cure in this patient group. We present the case of a late and extensively relapsed nonseminomatous germ cell tumour with thrombus present along the entire length of the inferior vena cava, as well as in the right hepatic vein. Techniques practised in liver transplantation were used to achieve complete resection of the tumour thrombus. This case illustrates the enhanced potential for tumour resection through a fusion of principles derived from surgical oncology and liver transplantation. PMID:25587480

  18. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

    SciTech Connect

    Kheradmand, Arash, E-mail: arashkheradmand@yahoo.com [Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of)] [Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Dezfoulian, Omid [Department of Pathobiology, School of Veterinary Medicine, Lorestan University, Khorram Abad (Iran, Islamic Republic of)] [Department of Pathobiology, School of Veterinary Medicine, Lorestan University, Khorram Abad (Iran, Islamic Republic of); Alirezaei, Masoud [Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of)] [Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Rasoulian, Bahram [Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khorram Abad (Iran, Islamic Republic of)] [Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khorram Abad (Iran, Islamic Republic of)

    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, ghrelin balanced Bax/Bcl-2 ratio toward at increase of Bax level in the spermatocytes and therefore may stimulate apoptosis in these germ cells. In contrast, ghrelin administration significantly suppressed proliferation-associated peptide PCNA in the spermatocytes as well as spermatogonia (P < 0.05). Whereas, caspase-3 activity did not show any marked alteration during the experiment in both groups (P > 0.05). Upstream of Bax substance parallel to down-regulation of PCNA demonstrate that ghrelin may prevent massive accumulation of germ cells during normal spermatogenesis. These observations also indicate that ghrelin may be considered as a modulator of spermatogenesis in normal adult rats and could be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors.

  19. Formation of germ-line cysts with a central cytoplasmic core is accompanied by specific orientation of mitotic spindles and partitioning of existing intercellular bridges

    Microsoft Academic Search

    Piotr ?wi?tek; Janusz Kubrakiewicz; Jerzy Klag

    2009-01-01

    Animal germ cells tend to form clonal groups known as clusters or cysts. Germ cells within the cyst (cystocytes) are interconnected\\u000a by intercellular bridges and thus constitute a syncytium. Our knowledge of the mechanisms that control the formation of germ-cell\\u000a clusters comes from extensive studies carried on model organisms (Drosophila, Xenopus). Germ-cell clusters have also been described in worms (annelids,

  20. Two Isoforms of Drosophila TRF2 Are Involved in Embryonic Development, Premeiotic Chromatin Condensation, and Proper Differentiation of Germ Cells of Both Sexes

    PubMed Central

    Kopytova, Daria V.; Krasnov, Aleksey N.; Kopantceva, Marina R.; Nabirochkina, Elena N.; Nikolenko, Julia V.; Maksimenko, Oksana; Kurshakova, Maria M.; Lebedeva, Lubov A.; Yerokhin, Maksim M.; Simonova, Olga B.; Korochkin, Leonid I.; Tora, Laszlo; Georgiev, Pavel G.; Georgieva, Sofia G.

    2006-01-01

    The Drosophila TATA box-binding protein (TBP)-related factor 2 (TRF2 or TLF) was shown to control a subset of genes different from that controlled by TBP. Here, we have investigated the structure and functions of the trf2 gene. We demonstrate that it encodes two protein isoforms: the previously described 75-kDa TRF2 and a newly identified 175-kDa version in which the same sequence is preceded by a long N-terminal domain with coiled-coil motifs. Chromatography of Drosophila embryo extracts revealed that the long TRF2 is part of a multiprotein complex also containing ISWI. Both TRF2 forms are detected at the same sites on polytene chromosomes and have the same expression patterns, suggesting that they fulfill similar functions. A study of the manifestations of the trf2 mutation suggests an essential role of TRF2 during embryonic Drosophila development. The trf2 gene is strongly expressed in germ line cells of adult flies. High levels of TRF2 are found in nuclei of primary spermatocytes and trophocytes with intense transcription. In ovaries, TRF2 is present both in actively transcribing nurse cells and in the transcriptionally inactive oocyte nuclei. Moreover, TRF2 is essential for premeiotic chromatin condensation and proper differentiation of germ cells of both sexes. PMID:17015475

  1. Effects of wheat germ agglutinin on human gastrointestinal epithelium: Insights from an experimental model of immune/epithelial cell interaction

    SciTech Connect

    Pellegrina, Chiara Dalla [Department of Biotechnology, University of Verona, Strada Le Grazie 15-CV1, I-37134 Verona (Italy); Perbellini, Omar [Department of Clinical and Experimental Medicine, University of Verona, I-37134 Verona (Italy); Scupoli, Maria Teresa [Department of Clinical and Experimental Medicine, University of Verona, I-37134 Verona (Italy); Interdepartmental Laboratory for Medical Research, University of Verona, I-37134 Verona (Italy); Tomelleri, Carlo [Department of Clinical and Experimental Medicine, University of Verona, I-37134 Verona (Italy); Zanetti, Chiara; Zoccatelli, Gianni; Fusi, Marina; Peruffo, Angelo; Rizzi, Corrado [Department of Biotechnology, University of Verona, Strada Le Grazie 15-CV1, I-37134 Verona (Italy); Chignola, Roberto [Department of Biotechnology, University of Verona, Strada Le Grazie 15-CV1, I-37134 Verona (Italy)], E-mail: roberto.chignola@univr.it

    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.

  2. T e c h n i c a l B u l l e t i n TNT Coupled Wheat Germ

    E-print Network

    Kirschner, Marc W.

    T e c h n i c a l B u l l e t i n TNT® Coupled Wheat Germ Extract Systems INSTRUCTIONS FOR USE A. General Protocol for TNT® Wheat Germ Extract Coupled Transcription/Translation Reactions.................................................................................................21 I. Description The TNT® Coupled Wheat Germ Extract Systems(a­d) offer researchers an alternative

  3. 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...

  4. GLD-4-Mediated Translational Activation Regulates the Size of the Proliferative Germ Cell Pool in the Adult C. elegans Germ Line

    PubMed Central

    Millonigg, Sophia; Eckmann, Christian R.

    2014-01-01

    To avoid organ dysfunction as a consequence of tissue diminution or tumorous growth, a tight balance between cell proliferation and differentiation is maintained in metazoans. However, cell-intrinsic gene expression mechanisms controlling adult tissue homeostasis remain poorly understood. By focusing on the adult Caenorhabditis elegans reproductive tissue, we show that translational activation of mRNAs is a fundamental mechanism to maintain tissue homeostasis. Our genetic experiments identified the Trf4/5-type cytoplasmic poly(A) polymerase (cytoPAP) GLD-4 and its enzymatic activator GLS-1 to perform a dual role in regulating the size of the proliferative zone. Consistent with a ubiquitous expression of GLD-4 cytoPAP in proliferative germ cells, its genetic activity is required to maintain a robust proliferative adult germ cell pool, presumably by regulating many mRNA targets encoding proliferation-promoting factors. Based on translational reporters and endogenous protein expression analyses, we found that gld-4 activity promotes GLP-1/Notch receptor expression, an essential factor of continued germ cell proliferation. RNA-protein interaction assays documented also a physical association of the GLD-4/GLS-1 cytoPAP complex with glp-1 mRNA, and ribosomal fractionation studies established that GLD-4 cytoPAP activity facilitates translational efficiency of glp-1 mRNA. Moreover, we found that in proliferative cells the differentiation-promoting factor, GLD-2 cytoPAP, is translationally repressed by the stem cell factor and PUF-type RNA-binding protein, FBF. This suggests that cytoPAP-mediated translational activation of proliferation-promoting factors, paired with PUF-mediated translational repression of differentiation factors, forms a translational control circuit that expands the proliferative germ cell pool. Our additional genetic experiments uncovered that the GLD-4/GLS-1 cytoPAP complex promotes also differentiation, forming a redundant translational circuit with GLD-2 cytoPAP and the translational repressor GLD-1 to restrict proliferation. Together with previous findings, our combined data reveals two interconnected translational activation/repression circuitries of broadly conserved RNA regulators that maintain the balance between adult germ cell proliferation and differentiation. PMID:25254367

  5. Earth's Layers

    NSDL National Science Digital Library

    Mrs. Walls

    2011-01-30

    Complete a poster all about Earth's Layers! Directions: Make a poster about Earth's Layers. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about Earth's Layers. (5 points each) (15 points) Write at least a three sentence summary of your poster ...

  6. Regulation of sex chromosome constitution of somatic and germ cells in the wood lemming

    E-print Network

    Paris-Sud XI, Université de

    Regulation of sex chromosome constitution of somatic and germ cells in the wood lemming A. GROPP K displays certain peculiar features. (a) The sex ratio shows a prevalence of females, and some females produce only female offspring. (b) A conside- rable proportion of the females has XY sex chromosomes

  7. Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways

    E-print Network

    Dean, Matthew D.

    REVIEW Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways / Accepted: 13 February 2012 / Published online: 2 March 2012 Ó Springer Basel AG 2012 Abstract Sex. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis

  8. In germ cells of mouse embryonic ovaries, the decision to enter meiosis precedes premeiotic DNA replication

    E-print Network

    Carpenter, Anne E.

    In germ cells of mouse embryonic ovaries, the decision to enter meiosis precedes premeiotic DNA Carpenter2, Dirk G de Rooij3 & David C Page1,2 The transition from mitosis to meiosis is a defining juncture in the life cycle of sexually reproducing organisms. In yeast, the decision to enter meiosis is made before

  9. Small RNA guides for de novo DNA methylation in mammalian germ cells

    PubMed Central

    Aravin, Alexei A.; Bourc’his, Déborah

    2008-01-01

    Germline genomic methylation is essential for gamete identity and integrity in mammals. The study by Kuramochi-Miyagawa and colleagues (908–917) in the previous issue of Genes & Development links the process of DNA methylation-dependent repression of retrotranspons with the presence of piwi-interacting RNAs (piRNAs) in fetal male germ cells undergoing de novo methylation. PMID:18413711

  10. 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

  11. Identification of a germ line transcript from the unrearranged kappa gene in human B cells.

    PubMed Central

    Martin, D J; Van Ness, B G

    1989-01-01

    A novel kappa immunoglobulin-hybridizing mRNA in cell lines derived from human B cells arrested at several stages of development has been identified. Hybridization studies demonstrate that this 1.5-kilobase mRNA species is the spliced product of a precursor germ line transcript initiating upstream of the unrearranged JKappa locus. Images PMID:2573834

  12. Proteasomal Regulation of the Proliferation vs. Meiotic Entry Decision in the Caenorhabditis elegans Germ Line

    PubMed Central

    MacDonald, Lindsay D.; Knox, Aaron; Hansen, Dave

    2008-01-01

    Reproductive fitness in many animals relies upon a tight balance between the number of cells that proliferate in the germ line and the number of cells that enter meiosis and differentiate as gametes. In the Caenorhabditis elegans germ line, the GLP-1/Notch signaling pathway controls this balance between proliferation and meiotic entry. Here we describe the identification of the proteasome as an additional regulator of this balance. We show that a decrease in proteasome activity, through either genetic mutation or RNAi to core components of the proteasome, shifts this balance toward excess germ-line proliferation. We further demonstrate that there are likely two or more proteasome targets that contribute to excess germ-line proliferation when proteasome activity is reduced. One of these targets is likely a component or regulator of the Notch-signaling pathway, while the other functions on one of the two major redundant genetic pathways downstream of GLP-1/Notch signaling. We propose a model in which the proteasome degrades proteins that are necessary for proliferation as cells switch from proliferation to meiotic entry. PMID:18791239

  13. PROCESSES FOR RECOVERY OF CORN GERM AND OPTIONALLY CORN COARSE FIBER (PERICARP)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A process for recovering corn germ and corn coarse fiber from corn in a dry grind process, involving soaking corn kernels in water to produce soaked corn kernels, grinding the soaked corn kernels to produce a ground corn slurry, and incubating the ground corn slurry with at least one enzyme(amylase(...

  14. Ultrastructure of sperm cells and the male germ unit in pollen tubes of Nicotiana tabacum

    Microsoft Academic Search

    Hong-Shi Yu; Shi-Yi Hu; Cheng Zhu

    1989-01-01

    Summary The structure of sperm cells and their association with the vegetative nucleus in pollen tubes ofNicotiana tabacum grown in styles were observed with the electron microscope, demonstrating the existence of a male germ unit. The two sperm cells are arranged in tandem and are closely associated with the vegetative nucleus, which always takes the lead. The leading sperm cell

  15. 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.

  16. 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...

  17. 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…

  18. Germ Line Fanconi Anemia Complementation Group C Mutations and Pancreatic Cancer

    Microsoft Academic Search

    Fergus J. Couch; Michele R. Johnson; Kari Rabe; Lisa Boardman; Robert McWilliams; Mariza de Andrade; Gloria Petersen

    Biallelic mutations in Fanconi anemia complementation group genes disrupt DNA repair and result in the complex Fanconi anemia phenotype. In addition, germ line mutations in the BRCA2\\/FANCD1 Fanconi anemia complementation group gene have also been implicated in predisposition to a number of cancers including pancreatic cancer. The recent identification of FANCC and FANCG mutations in resected pancreatic tumors selected for

  19. GERM in EarthRef.org: A reference model approach to data bases

    Microsoft Academic Search

    H. Staudigel; A. A. Koppers; C. Cxonstable; J. Helly

    2002-01-01

    The geochemical earth reference model (GERM) initiative is a grass-roots effort that works towards a chemical characterization of the whole earth, from the core to the atmosphere. This reference model aims to provide the currently best possible geochemical constraints that characterize every geochemical reservoir, as a reference point for comparison with data from future studies to improve these estimates. The

  20. 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

  1. Isolation and characterization of a cDNA clone encoding wheat germ agglutinin

    SciTech Connect

    Raikhel, N.V.; Wilkins, T.A.

    1987-10-01

    Two sets of synthetic oligonucleotides coding for amino acids in the amino- and carboxyl-terminal portions of wheat germ agglutinin were synthesized and used as hybridization probes to screen cDNA libraries derived from developing embryos of tetraploid wheat. The nucleotide sequence for a cDNA clone recovered from the cDNA library was determined by dideoxynucleotide chain-termination sequencing in vector M13. The amino acid sequence deduced from the DNA sequence indicated that this cDNA clone (pNVR1) encodes isolectin 3 of wheat germ agglutinin. Comparison of the deduced amino acid sequence of clone pNVR1 with published sequences indicates isolectin 3 differs from isolectins 1 and 2 by 10 and 8 amino acid changes, respectively. In addition, the protein encoded by pNVR1 extends 15 amino acids beyond the carboxyl terminus of the published amino acid sequence for isolectins 1 and 2 and includes a potential site for N-linked glycosylation. Utilizing the insert of pNVR1 as a hybridization probe, the authors have demonstrated that the expression of genes for wheat germ agglutinin is modulated by exogenous abscisic acid. Striking homology is observed between wheat germ agglutinin and chitinase, both of which are proteins that bind chitin.

  2. Module title: GERMAN Accelerated Language stages 1-2 Module code: GERM9040

    E-print Network

    Anderson, Jim

    Module title: GERMAN Accelerated Language stages 1-2 Module code: GERM9040 1. School (and/French and German as well as Spanish/French and German (Linguistic Studies) with German studied ab initio 6. As a competent language user at the end of this Stage, and after a notional 300 hours study time (class contact

  3. Composition and oxidative stability of crude oil extracts of corn germ and distillers grains

    Microsoft Academic Search

    Jill K. Winkler-Moser; Lotta Breyer

    2011-01-01

    The fatty acid composition, Acid Value, and the content and composition of tocopherols, tocotrienols, carotenoids, phytosterols, and steryl ferulates were determined in corn germ oil and four post-fermentation corn oils from the ethanol dry grind process. The oxidative stability index at 110°C was determined for the five oils, and four oils were compared for their stability during storage at 40°C

  4. Optimized gene editing technology for Drosophila melanogaster using germ line-specific Cas9

    E-print Network

    Perrimon, Norbert

    9 is specifically expressed in the germ line via the nanos promoter. We evaluate the off-targets studies. Recent advances using the CRISPR-associated single-guide RNA system (Cas9/sgRNA) illustrate. In contrast, the recent approach based on the bacterial CRISPR- associated sin- gle-guide RNA (Cas9/sg

  5. Grinding and cooking dry-mill germ to optimize aqueous enzymatic oil extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The many recent dry grind plants that convert corn to ethanol are potential sources of substantial amounts of corn oil. This report describes an aqueous enzymatic extraction (AEE) method to separate oil from dry-mill corn germ (DMG). The method is an extension of AEE previously developed for wet...

  6. Evidence for Endoreduplication: Germ Cell DNA Levels Prior to Chromatin Diminution in Mesocyclops edax

    Microsoft Academic Search

    Ellen M. Rasch; Grace A. Wyngaard

    SUMMARY We studied the functional significance of marked differences in the DNA con- tent of somatic cells and germ line nuclei by static Feulgen-DNA cytophotometry for sev- eral species of microcrustaceans that exhibit chromatin diminution during very early stages of embryogenesis. Mature females and males showed many gonadal nuclei with elevated amounts of DNA that persist until dispersal of this

  7. A Niche Maintaining Germ Line Stem Cells in the Drosophila Ovary

    Microsoft Academic Search

    Ting Xie; Allan C. Spradling

    2000-01-01

    Stromal cells are thought to generate specific regulatory microenviroments or ``niches'' that control stem cell behavior. Characterizing stem cell niches in vivo remains an important goal that has been difficult to achieve. The individual ovarioles of the Drosophila ovary each contain about two germ line stem cells that maintain oocyte production. Here we show that anterior ovariolar somatic cells comprising

  8. Mouse Ovarian Germ Cell Cysts Undergo Programmed Breakdown to Form Primordial Follicles

    Microsoft Academic Search

    Melissa E. Pepling; Allan C. Spradling

    2001-01-01

    In many organisms, early germline development takes place within cysts of interconnected cells that form by incomplete cytokinesis and later undergo programmed breakdown. We recently identified similar cell clusters within the fetal mouse ovary, but the fate and functional significance of these germ cell cysts remained unclear. Here, we show that mouse cysts undergo programmed breakdown between 20.5–22.5 dpc, during

  9. Regulated transposition of a fish transposon in the mouse germ line

    PubMed Central

    Fischer, Sylvia E. J.; Wienholds, Erno; Plasterk, Ronald H. A.

    2001-01-01

    Tc1/mariner elements are able to transpose in species other than the host from which they were isolated. As potential vectors for insertional mutagenesis and transgenesis of the mouse, these cut-and-paste transposons were tested for their ability to transpose in the mouse germ line. First, the levels of activity of several Tc1/mariner elements in mammalian cells were compared; the reconstructed fish transposon Sleeping Beauty (SB) was found to be an order of magnitude more efficient than the other tested transposons. SB then was introduced into the mouse germ line as a two-component system: one transgene for the expression of the transposase in the male germ line and a second transgene carrying a modified transposon. In 20% of the progeny of double transgenic male mice the transposon had jumped from the original chromosomal position into another locus. Analysis of the integration sites shows that these jumps indeed occurred through the action of SB transposase, and that SB has a strong preference for intrachromosomal transposition. Analysis of the excision sites suggests that double-strand breaks in haploid spermatids are repaired via nonhomologous end joining. The SB system may be a powerful tool for transposon mutagenesis of the mouse germ line. PMID:11381141

  10. WHEAT GERM SUPPLEMENT REDUCES CYST AND TROPHOZOITE PASSAGE IN PEOPLE WITH GIARDIASIS

    Microsoft Academic Search

    JENNIFER GRANT; SIDDHARTHA MAHANTY; AMIR KHADIR; J. DICK M ACLEAN; EVELYNE KOKOSKIN; BETH YEAGER; LAWRENCE JOSEPH; JUDITH DIAZ; EDUARDO GOTUZZO; NORMAN MAINVILLE; BRIAN J. WARD

    2001-01-01

    The protozoan parasite Giardia lamblia is a major cause of waterborne enteric disease worldwide. Lectins are proteins that bind to carbohydrate (sugar) moieties. Potential targets for lectins are found on the surface of most single-celled organisms. Modest concentrations of wheat germ agglutinin (WGA) have been shown to inhibit G. lamblia excystation and trophozoite growth in vitro and can reduce cyst

  11. TERATOMA WITH MALIGNANT TRANSFORMATION: DIVERSE MALIGNANT HISTOLOGIES ARISING IN MEN WITH GERM CELL TUMORS

    Microsoft Academic Search

    Robert J. Motzer; Alison Amsterdam; Victor Prieto; Joel Sheinfeld; V. V. V. S. Murty; Madhu Mazumdar; George J. Bosl; R. S. K. Chaganti; Victor E. Reuter

    1998-01-01

    PurposeTeratoma with malignant transformation refers to a form of germ cell tumor in which a somatic teratomatous component becomes morphologically malignant and develops aggressive growth. We evaluated the spectrum of histologies, chromosomal abnormalities and clinical outcome in patients with teratoma with malignant transformation.

  12. Increased mortality rates in young and middle-aged patients with malignant germ cell tumours

    Microsoft Academic Search

    S D Fosså; N Aass; S Harvei; S Tretli

    2004-01-01

    Cisplatin-based chemotherapy of malignant germ cell tumours (MGCT) has been reported to increase the risk of cardiovascular morbidity. A high incidence of second nongerm cell malignancies is well documented in MGCT survivors. The death risk due to these conditions is, however, more unknown in MGCT patients. Standard mortality rates (SMRs) were established in 3378 Norwegian MGCT patients treated from 1962

  13. Quantification of Vitamin E and gamma-Oryzanol Components in Rice Germ and Bran

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice bran is a rich natural source of vitamin E and gamma-oryzanol, which have been extensively studied and reported to possess important health-promoting properties. However, commercial rice bran is a mixture of rice bran and germ, and profiles of vitamin E and gamma-oryzanol components in these tw...

  14. Control of Sertoli and germ cell populations in the cock and sheep testes

    E-print Network

    Paris-Sud XI, Université de

    Control of Sertoli and germ cell populations in the cock and sheep testes M. de REVIERS, Marie in the cock and ram testes to determine their controlling factors : initial number, endocrine environment to the natural environment and hemicastrated as impuberal when 6 weeks old. They were compared to normal animals

  15. Repeat expansion by homologous recombination in the mouse germ line at palindromic sequences

    Microsoft Academic Search

    Zhi-Hong Zhou; Ercan Akgün; Maria Jasin

    2001-01-01

    Cell Biology Program, Sloan-Kettering Institute and Cornell University Graduate School of Medical Sciences, 1275 York Avenue, New York, NY 10021 Genetic instability can be induced by unusual DNA structures and sequence repeats. We have previously demonstrated that a large palindrome in the mouse germ line derived from transgene integration is extremely unstable and undergoes stabilizing rearrangements at high frequency, often

  16. Transposon silencing in the Caenorhabditis elegans germ line by natural RNAi

    Microsoft Academic Search

    Titia Sijen; Ronald H. A. Plasterk

    2003-01-01

    Transposable elements are stretches of DNA that can move and multiply within the genome of an organism. The Caenorhabditis elegans genome contains multiple Tc1 transposons that jump in somatic cells, but are silenced in the germ line. Many mutants that have lost this silencing have also lost the ability to execute RNA interference (RNAi), a process whereby genes are suppressed

  17. EXPRESSION OF EGFL7 IN PRIMORDIAL GERM CELLS AND IN ADULT OVARIES AND TESTES

    PubMed Central

    Campagnolo, Luisa; Moscatelli, Ilana; Pellegrini, Manuela; Siracusa, Gregorio; Stuhlmann, Heidi

    2008-01-01

    We have previously reported the isolation and characterization of a novel endothelial-restricted gene, Egfl7, that encodes a secreted protein of about 30-kDa. We and others demonstrated that Egfl7 is highly expressed by endothelial cells during embryonic development and becomes down-regulated in the adult vasculature. In the present paper we show that during mouse embryonic development, Egfl7 is also expressed by primordial germ cells (PGC). Expression is down-regulated when PGCs differentiate into pro-spermatogonia and oogonia, and by 15.5 dpc Egfl7 can no longer be detected in the germ line of both sexes. Notably, Egfl7 is again transiently up-regulated in germ cells of the adult testis. In contrast, expression in the ovary remains limited to the vascular endothelium. Our results provide the first evidence of a non-endothelial expression of EGFL7 and suggest distinctive roles for Egfl7 in vascular development and germ cell differentiation. PMID:18556249

  18. Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells.

    PubMed

    Brieño-Enríquez, Miguel A; García-López, Jesús; Cárdenas, David B; Guibert, Sylvain; Cleroux, Elouan; D?d, Lukas; Hourcade, Juan de Dios; P?knicová, Jana; Weber, Michael; Del Mazo, Jesús

    2015-01-01

    In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation. PMID:25897752

  19. Evaluation of Elevated Dietary Corn Fiber from Corn Germ Meal in Growing Female Pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the effects of high dietary corn fiber on growth and metabolic measures, female pigs (n= 48; initial body weight of 30.8 kg) were fed diets containing 0 to 38.6% solvent-extracted corn germ meal for 28 days. Increasing the level of dietary corn fiber had no impact on average daily gain o...

  20. 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

  1. Clean and DisinfectClean and DisinfectClean and Disinfect Germ Fighting 101

    E-print Network

    Clean and DisinfectClean and DisinfectClean and Disinfect Germ Fighting 101 Non-Porous Surfaces A dishwashing machine can substitute in cleaning and disinfecting of toys and dishes 1. Clean surface with a mild detergent to remove visible signs of dirt 2. Then disinfect with: · EPA registered disinfectant

  2. Plant Disease / September 2002 10431043 Perennial Wheat Germ Plasm Lines Resistant to Eyespot, Cephalosporium Stripe,

    E-print Network

    Murray, Timothy D.

    Plant Disease / September 2002 10431043 Perennial Wheat Germ Plasm Lines Resistant to Eyespot, Cephalosporium Stripe, and Wheat Streak Mosaic C. M. Cox, Former Graduate Research Assistant, Department of Plant are needed that are ecologically and economically sustainable. Perennial wheat has the potential to con- vert

  3. Genetic anomalies in mammalian germ cells and their significance for human reproductive and developmental risk.

    PubMed Central

    Dellarco, V L

    1993-01-01

    The induction of heritable mutations in germ cells represents a potential health concern. This paper highlights data from mouse germ-cell mutagenesis studies that have implications in the assessment of reproductive and developmental risks. The paper discusses the developmental and reproductive consequences of induced chromosomal damage (structural rearrangements and numerical anomalies) and describes environmental agents that have been shown to produce such anomalies. Additionally, factors that influence the yield of genetic damage are addressed. Studies showing that the various germ-cell stages vary in their susceptibility to the induction of genetic damage are summarized. Of the chemicals evaluated in the male mouse, most appear to have their predominant or strongest effect on post-stem-cell stages. The differences between males and females in the susceptibility to mutagens is examined. Recent studies have shown that the female may be uniquely sensitive to certain mutagens. Finally, an important aspect of mutagenic risk is not only effects induced in developing germ cells but also the effects of environmental agents during the period from fertilization through the zygote and the two-cell embryo. Recent work in the mouse has demonstrated that exposure during these early developmental stages leads to high frequencies of external and visceral fetal malformations, as well as mid-to-late gestational death. PMID:8243406

  4. Gene expression profiling differentiates germ cell tumors from other cancers and defines

    E-print Network

    Ford, James

    pathways knowledge databases revealed a potential role of EGR1 in p21-induced cell cycle arrest malignancies. We identified 511 genes, belonging to several critical functional groups such as cell cycleGene expression profiling differentiates germ cell tumors from other cancers and defines subtype

  5. GERMS: an epidemiologic simulation tool for studying geographic and social effects on infection transmission

    Microsoft Academic Search

    Andrew L. Adams; James S. Koopman; Stephen E. Chick; Peter J. Yu

    1999-01-01

    The analysis, surveillance and control of infectious diseases are important functions of public health organizations around the world. This article describes the design and implementation of a simulation toolkit called GERMS (Geographic-Environmental Reinfection Modeling Simulator) that includes several innovations for modeling infectious disease transmission. These tools address several important issues for understanding the epidemiology of sexually transmitted infections. The model

  6. Inter-Regional, Epidemiological Study of Childhood Cancer (IRESCC): case-control study in children with germ cell tumors

    SciTech Connect

    Johnston, H.E.; Mann, J.R.; Williams, J.; Waterhouse, J.A.; Birch, J.M.; Cartwright, R.A.; Draper, G.J.; Hartley, A.L.; McKinney, P.A.; Hopton, P.A.

    1986-05-01

    In 1980-1983 members of IRESCC interviewed parents of 555 children with newly diagnosed cancer on topics of possible etiological significance. Identical questions were asked of the parents of 1100 control children chosen from hospital admissions and general practitioner lists. Medical information was confirmed whenever possible by cross-checking with NHS records. Data for the 41 children with germ cell tumors and their 82 controls are reported here. The cases had more major congenital malformations than controls, including one neural tube defect. More case than control mothers and fathers reported occupational exposure to chemicals. Nine close relatives of cases had multiple primary tumors, which were often benign or of low-grade malignancy, compared with 1 hospital control and 3 general practitioner control relatives. Cases and controls differed with respect to birth weight and paternal age. No case-control differences were shown for: birth rank, maternal age, chronic illnesses and smoking, mothers reproductive histories and oral contraceptive usage. In index pregnancies there were no case-control differences for maternal illness, infections, alcohol intake and X-ray and ultrasound exposure. There was no difference between cases and controls for the frequency of twinning the families.

  7. Experimentally induced depletion of germ cells in sub-adult Patagonian pejerrey (Odontesthes hatcheri).

    PubMed

    Majhi, S K; Hattori, R S; Rahman, Sk M; Suzuki, T; Strüssmann, C A

    2009-04-15

    Germ cell (GC) transplantation (GCT) is a novel reproductive technology with application in seed production and conservation of endangered species. This study examined the suitability of treatment with Busulfan, a cytotoxic agent, and warm water, known to cause GC degeneration, for depletion of endogenous GCs in sub-adult Patagonia pejerrey Odontesthes hatcheri intended as hosts in GCT. In two experiments, fish were treated with six combinations of temperature (intermediate and high, 20 and 25 degrees C, respectively) and Busulfan (0, 20, and 40 mg/kg body weight), given intraperitoneally (ip) as a single (0 week) or repeated (0 and 4 week) dose. The effectiveness of the treatments was assessed by gonado-somatic index, histology, and (germ cell-specific) vasa gene expression after 8 weeks. Fish were allowed to recover at 17 degrees C for 4-8 weeks after the treatments to ascertain the permanency of the effects. The high temperature (25 degrees C) alone induced only incipient gonadal degeneration and germ cell loss, but was highly effective in combination with double administration of 40 mg/kg Busulfan. Males tolerated Busulfan better and were more easily depleted of germ cells than females. Animals treated for 8 weeks were severely devoid of germ cells, but were still capable of gametogenesis. Thus, the combination of Busulfan and high water temperature appeared to be efficient for depletion of GCs in adult fish; and the treated gonads retained the ability to support GC proliferation and differentiation. Furthermore, quantitative analysis of vasa transcript levels was found to be an useful to monitor the degree of gonad sterility during treatment. PMID:19168208

  8. 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

  9. Germ-line mutation analysis in patients with multiple endocrine neoplasia type 1 and related disorders.

    PubMed Central

    Giraud, S; Zhang, C X; Serova-Sinilnikova, O; Wautot, V; Salandre, J; Buisson, N; Waterlot, C; Bauters, C; Porchet, N; Aubert, J P; Emy, P; Cadiot, G; Delemer, B; Chabre, O; Niccoli, P; Leprat, F; Duron, F; Emperauger, B; Cougard, P; Goudet, P; Sarfati, E; Riou, J P; Guichard, S; Rodier, M; Meyrier, A; Caron, P; Vantyghem, M C; Assayag, M; Peix, J L; Pugeat, M; Rohmer, V; Vallotton, M; Lenoir, G; Gaudray, P; Proye, C; Conte-Devolx, B; Chanson, P; Shugart, Y Y; Goldgar, D; Murat, A; Calender, A

    1998-01-01

    Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant syndrome predisposing to tumors of the parathyroid, endocrine pancreas, anterior pituitary, adrenal glands, and diffuse neuroendocrine tissues. The MEN1 gene has been assigned, by linkage analysis and loss of heterozygosity, to chromosome 11q13 and recently has been identified by positional cloning. In this study, a total of 84 families and/or isolated patients with either MEN1 or MEN1-related inherited endocrine tumors were screened for MEN1 germ-line mutations, by heteroduplex and sequence analysis of the MEN1 gene-coding region and untranslated exon 1. Germ-line MEN1 alterations were identified in 47/54 (87%) MEN1 families, in 9/11 (82%) isolated MEN1 patients, and in only 6/19 (31.5%) atypical MEN1-related inherited cases. We characterized 52 distinct mutations in a total of 62 MEN1 germ-line alterations. Thirty-five of the 52 mutations were frameshifts and nonsense mutations predicted to encode for a truncated MEN1 protein. We identified eight missense mutations and five in-frame deletions over the entire coding sequence. Six mutations were observed more than once in familial MEN1. Haplotype analysis in families with identical mutations indicate that these occurrences reflected mainly independent mutational events. No MEN1 germ-line mutations were found in 7/54 (13%) MEN1 families, in 2/11 (18%) isolated MEN1 cases, in 13/19 (68. 5%) MEN1-related cases, and in a kindred with familial isolated hyperparathyroidism. Two hundred twenty gene carriers (167 affected and 53 unaffected) were identified. No evidence of genotype-phenotype correlation was found. Age-related penetrance was estimated to be >95% at age >30 years. Our results add to the diversity of MEN1 germ-line mutations and provide new tools in genetic screening of MEN1 and clinically related cases. PMID:9683585

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

    PubMed Central

    Frebourg, T; Barbier, N; Yan, Y X; Garber, J E; Dreyfus, M; Fraumeni, J; Li, F P; Friend, S H

    1995-01-01

    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 15 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.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7887414

  11. Seminiferous cord formation and germ-cell programming: epigenetic transgenerational actions of endocrine disruptors.

    PubMed

    Skinner, Michael K; Anway, Matthew D

    2005-12-01

    The molecular and cellular control of embryonic testis development was investigated through an analysis of the embryonic testis transcriptome to identify potential regulatory factors for male sex determination and testis morphogenesis. One critical factor identified is neurotropin 3 (NT3). At the onset of male sex determination, Sertoli cells initiate differentiation and express NT3 to act as a chemotactic factor for mesonephros cells to migrate and associate with Sertoli-germ cell aggregates to promote cord formation. Promoter analysis suggests that NT3 may be an initial downstream gene to SRY and helps promote testis morphogenesis. Endocrine disruptors were used to potentially interfere with embryonic testis development and further investigate this biological process. The estrogenic pesticide methoxychlor and antiandrogenic fungicide vinclozolin were used. Previous studies have shown that methoxychlor and vinclozolin both interfere with embryonic testis cord formation and cause increased spermatogenic cell apoptosis in the adult testis. Interestingly, transient in vivo exposure to endocrine disruptors at the time of male sex determination caused a transgenerational phenotype (F1-F4) of spermatogenic cell apoptosis and subfertility. This apparent epigenetic mechanism involves altered DNA methylation and permanent re-programming of the male germ-line. A series of genes with altered DNA methylation and imprinting are being identified. Observations reviewed demonstrate that a transient embryonic in utero exposure to an endocrine disruptor influences the embryonic testis transcriptome and through epigenetic effects (e.g., DNA methylation) results in abnormal germ-cell differentiation that subsequently influences adult spermatogenic capacity and male fertility, and that this phenotype is transgenerational through the germ-line. The novel observations of transgenerational epigenetic endocrine disruptor actions on male reproduction critically impact the potential hazards of these compounds as environmental toxins. The literature reviewed provides insight into the molecular and cellular control of embryonic testis development, male sex determination, and the programming of the male germ-line. PMID:16467254

  12. Presidential Primaries

    NSDL National Science Digital Library

    The Washington Weekly (an Internet newspaper) offers a 1996 Presidential Primaries Page that is organized by candidate within each party. For most candidates there is biographical information, voting record, list of accomplishments or stands on key issues, and a connection to the candidate's home page when available. This is a non-graphical but well organized page that provides the user with quick access to voting records, speeches and press releases, and Web pages of the candidates.

  13. Germ Line Transmission of the Cdk4R24C Mutation Facilitates Tumorigenesis and Escape from Cellular Senescence

    PubMed Central

    Rane, Sushil G.; Cosenza, Stephen C.; Mettus, Richard V.; Reddy, E. Premkumar

    2002-01-01

    Mutations in CDK4 and its key kinase inhibitor p16INK4a have been implicated in the genesis and progression of familial human melanoma. The importance of the CDK4 locus in human cancer first became evident following the identification of a germ line CDK4-Arg24Cys (R24C) mutation, which abolishes the ability of CDK4 to bind to p16INK4a. To determine the role of the Cdk4R24C germ line mutation in the genesis of other cancer types, we introduced the R24C mutation in the Cdk4 locus of mice by using Cre-loxP-mediated “knock-in” technology. Cdk4R24C/R24C mouse embryo fibroblasts (MEFs) displayed increased Cdk4 kinase activity resulting in hyperphosphorylation of all three members of the Rb family, pRb, p107, and p130. MEFs derived from Cdk4R24C/R24C mice displayed decreased doubling times, escape from replicative senescence, and escape sensitivity to contact-induced growth arrest. These MEFs also exhibited a high degree of susceptibility to oncogene-induced transformation, suggesting that the Cdk4R24C mutation can serve as a primary event in the progression towards a fully transformed phenotype. In agreement with the in vitro data, homozygous Cdk4R24C/R24C mice developed tumors of various etiology within 8 to 10 months of their life span. The majority of these tumors were found in the pancreas, pituitary, brain, mammary tissue, and skin. In addition, Cdk4R24C/R24C mice showed extraordinary susceptibility to carcinogens and developed papillomas within the first 8 to 10 weeks following cutaneous application of the carcinogens 9,10-di-methyl-1,2-benz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). This report formally establishes that the activation of Cdk4 is sufficient to promote cancer in many tissues. The observation that a wide variety of tumors develop in mice harboring the Cdk4R24C mutation offers a genetic proof that Cdk4 activation may constitute a central event in the genesis of many types of cancers in addition to melanoma. PMID:11756559

  14. Phenotypic and Molecular Analysis of Mes-3, a Maternal-Effect Gene Required for Proliferation and Viability of the Germ Line in C. Elegans

    PubMed Central

    Paulsen, J. E.; Capowski, E. E.; Strome, S.

    1995-01-01

    mes-3 is one of four maternal-effect sterile genes that encode maternal components required for normal postembryonic development of the germ line in Caenorhabditis elegans. mes-3 mutant mothers produce sterile progeny, which contain few germ cells and no gametes. This terminal phenotype reflects two problems: reduced proliferation of the germ line and germ cell death. Both the appearance of the dying germ cells and the results of genetic tests indicate that germ cells in mes-3 animals undergo a necrotic-like death, not programmed cell death. The few germ cells that appear healthy in mes-3 worms do not differentiate into gametes, even after elimination of the signaling pathway that normally maintains the undifferentiated population of germ cells. Thus, mes-3 encodes a maternally supplied product that is required both for proliferation of the germ line and for maintenance of viable germ cells that are competent to differentiate into gametes. Cloning and molecular characterization of mes-3 revealed that it is the upstream gene in an operon. The genes in the operon display parallel expression patterns; transcripts are present throughout development and are not restricted to germ-line tissue. Both mes-3 and the downstream gene in the operon encode novel proteins. PMID:8601481

  15. Efficacy of wheat germ lectin-precipitated alkaline phosphatase in serum as an estimator of bone mineralization rate: Comparison to serum total alkaline phosphatase and serum bone Gla-protein

    Microsoft Academic Search

    Kim Brixen; Henning K. Nielsen; Erik F. Eriksen; Peder Charles; Leif Mosekilde

    1989-01-01

    Summary  Serum levels of total alkaline phosphatase activity (S-T-AP), wheat germ lectin-precipitated alkaline phosphatase activity\\u000a (S-L-AP), and bone Gla-protein immunoreactivity (S-BGP) were measured in 26 patients (23 females and 3 males) aged 35–73 years\\u000a (mean 59 years) with primary hyperparathyroidism (n=7), hyperthyroidism (n=9), and hypothyroidism (n=10) in whom the bone\\u000a mineralization rate (m) was determined by47Ca-kinetics (continuously expanding calcium pool model).

  16. Oocytes and embryos of Xenopus laevis express two different isoforms of germ cell nuclear factor (GCNF, NR6A1).

    PubMed

    Schohl, Anne; Barreto, Guillermo; Joos, Thomas O; Dreyer, Christine

    2002-10-01

    The germ cell nuclear factor (GCNF) is a nuclear orphan receptor and a putative regulator of the pluripotent state of cells. Although it was first described in mouse germ cells, GCNF is also expressed in mouse and Xenopus embryos. By means of 5'RACE we have identified a novel isoform of Xenopus laevis GCNF that is predominantly expressed in germ cells, whereas both the oocyte and embryonic forms are expressed during Xenopus embryogenesis. EST database search revealed that the homologues of both isoforms are also transcribed in Xenopus tropicalis. PMID:12351198

  17. Fetal germ cell development in the rat testis and the impact of di (n-Butyl) phthalate exposure 

    E-print Network

    Jobling, Matthew S.

    2010-01-01

    During gonad development and fetal life, the germ cells (GC) undergo a range of different developmental processes necessary for correct postnatal gametogenesis and the production of the next generation. If these fetal ...

  18. Circadian Proteins CLOCK and BMAL1 in the Chromatoid Body, a RNA Processing Granule of Male Germ Cells

    E-print Network

    Peruquetti, Rita L; de Mateo, Sara; Sassone-Corsi, Paolo; Tora, Laszlo

    2012-01-01

    cells seem to play important roles during the gametogenesis process [cells, is characterized by a number of unique and remarkable features. This processprocess that involves genetic and epigenetic regulation, sophisticated hormonal control, and extensive structural changes in male germ cells.

  19. Identification of a germ-line mutation in the p53 gene in a patient with an intracranial ependymoma

    SciTech Connect

    Metzger, A.K.; Duyk, G.; Daneshvar, L.; Edwards, M.S.B.; Cogen, P.H. (Univ. of California, San Francisco (United States)); Sheffield, V.C. (Univ. of Iowa, Iowa City (United States))

    1991-09-01

    The authors detected a germ-line mutation of the p53 gene in a patient with a malignant ependymoma of the posterior fossa. This mutation, which was found at codon 242, resulted in an amino acid substitution in a highly conserved site of exon 7 of the p53 gene; the same mutation was found in both the germ-line and tumor tissue. This is the most common region of previously described somatic p53 mutations in tumor specimens and of the germ-line p53 mutations in patients with the Li-Fraumeni cancer syndrome. Evaluation of the patient's family revealed several direct maternal and paternal relatives who had died at a young age from different types of cancer. The association of a germ-line p53 mutation with an intracranial malignancy and a strong family history of cancer suggests that p53 gene mutations predispose a person to malignancy and, like retinoblastoma mutations, may be inherited.

  20. Licensing of gametogenesis, dependent on RNA binding protein DAZL, as a gateway to sexual differentiation of fetal germ cells

    E-print Network

    Gill, Mark E.

    Mammalian oocytes and spermatozoa derive from fetal cells shared by the sexes. These primordial germ cells (PGCs) migrate to the developing somatic gonad, giving rise to oocytes or spermatozoa. These opposing sexual fates ...

  1. Germ-Line Recombination Activity of the Widely Used hGFAP-Cre and Nestin-Cre Transgenes

    PubMed Central

    Zhang, Jiong; Dublin, Pavel; Griemsmann, Stephanie; Klein, Alexandra; Brehm, Ralph; Bedner, Peter; Fleischmann, Bernd K.; Steinhäuser, Christian; Theis, Martin

    2013-01-01

    Herein we demonstrate with PCR, immunodetection and reporter gene approaches that the widely used human Glial Fibrillary Acidic Protein (hGFAP)-Cre transgene exhibits spontaneous germ-line recombination activity in leading to deletion in brain, heart and tail tissue with high frequency. The ectopic activity of hGFAP-Cre requires a rigorous control. We likewise observed that a second widely used nestin-Cre transgene shows germ-line deletion. Here we describe procedures to identify mice with germ-line recombination mediated by the hGFAP-Cre and nestin-Cre transgenes. Such control is essential to avoid pleiotropic effects due to germ-line deletion of loxP-flanked target genes and to maintain the CNS-restricted deletion status in transgenic mouse colonies. PMID:24349371

  2. PRIMARY CARE ASSOCIATE PROGRAM PRIMARY PRECEPTOR MANUAL

    E-print Network

    Puglisi, Joseph

    PRIMARY CARE ASSOCIATE PROGRAM 2011-2013 PRIMARY PRECEPTOR MANUAL http://pcap.stanford.edu 1215 or Supplemental Preceptor PRIMARY PRECEPTOR/PRIMARY CARE ASSOCIATE PROGRAM RELATIONSHIP PRECEPTOR REQUIREMENTS: Thank you for your interest in precepting a student in the Primary Care Associate Program. Your services

  3. Replacement of Germ-Line ? Promoter by Gene Targeting Alters Control of Immunoglobulin Heavy Chain Class Switching

    Microsoft Academic Search

    Lixing Xu; Beverly Gorham; Suzanne C. Li; Andrea Bottaro; Frederick W. Alt; Paul Rothman

    1993-01-01

    Recent work has shown that the ability of cytokines to direct immunoglobulin heavy chain class-switch recombination to particular heavy chain constant (C) region (C_H) genes correlates with the induction of specific germ-line C_H transcripts. To test the role of germ-line transcripts in class switching, we have used homologous recombination to mutate the immunoglobulin heavy chain locus of the 18.81A20 murine

  4. On Facts and Conceptual Systems: Young Children’s Integration of Their Understandings of Germs and Contagion

    Microsoft Academic Search

    Gregg E. A. Solomon; Nicholas L. Cassimatis

    1999-01-01

    Five studies argue against claims that preschoolers understand a biological germ theory of illness. In Studies 1–3, participants were read stories in which characters develop symptoms (e.g., a bellyache) caused by germs, poisons, or events (e.g., eating too much candy) and were asked whether another character could catch the symptoms from the first. Few children made judgments in terms of

  5. Renal Carcinogenesis, Hepatic Hemangiomatosis, and Embryonic Lethality Caused by a Germ-Line Tsc2 Mutation in Mice1

    Microsoft Academic Search

    Toshiyuki Kobayashi; Osamu Minowa; Junko Kuno; Hiroaki Mitani; Okio Hino; Tetsuo Noda

    1999-01-01

    Germ-line mutations of the human TSC2 tumor suppressor gene cause tuberous sclerosis (TSC), a disease characterized by the development of hamartomas in various organs. In the Eker rat, however, a germ-line Tsc2 mutation gives rise to renal cell carcinomas with a complete penetrance. The molecular mechanism for this phenotypic difference between man and rat is currently unknown, and the physiological

  6. Identification of a germ-line mutation in the p53 gene in a patient with an intracranial ependymoma

    Microsoft Academic Search

    A. K. Metzger; G. Duyk; L. Daneshvar; M. S. B. Edwards; P. H. Cogen; V. C. Sheffield

    1991-01-01

    The authors detected a germ-line mutation of the p53 gene in a patient with a malignant ependymoma of the posterior fossa. This mutation, which was found at codon 242, resulted in an amino acid substitution in a highly conserved site of exon 7 of the p53 gene; the same mutation was found in both the germ-line and tumor tissue. This

  7. Germ cell comparative Drosophila mutagenesis: sensitivity and mutation pattern in chemically treated stem cells

    SciTech Connect

    Abrahamson, S.; Houtchens, K.; Li Jia, X.; Foureman, P.

    1983-01-01

    Mutagenesis studies on Drosophila oogonial cells with methylnitrosourea, dimethylnitrosamine, and diethylnitrosamine revealed unexpectedly high rates of sex-linked recessive lethals relative to other male and female germ cell stages. Indeed, the oogonial mutation rates with chemicals are higher than with massive x-ray or neutron exposures of oogonia. Analysis of the distribution of lethals per treated female suggests most of the mutations recovered are of independent origin, with very small levels of clustering of identical mutations. In the male stem cell population (spermatogonia) on the other hand, the distribution of lethals is primarily nonrandom and highly clustered. The nature of the mutational endpoint and the different pattern of germ cell development in the two sexes are the probable causes of this difference. The oogonial sensitivity to chemical mutagens may have important bearing on strategies for assessing human hazard.

  8. Synaptonemal Complex Components Promote Centromere Pairing in Pre-meiotic Germ Cells

    PubMed Central

    Huynh, Jean-René

    2013-01-01

    Mitosis and meiosis are two distinct cell division programs. During mitosis, sister chromatids separate, whereas during the first meiotic division, homologous chromosomes pair and then segregate from each other. In most organisms, germ cells do both programs sequentially, as they first amplify through mitosis, before switching to meiosis to produce haploid gametes. Here, we show that autosomal chromosomes are unpaired at their centromeres in Drosophila germline stem cells, and become paired during the following four mitosis of the differentiating daughter cell. Surprisingly, we further demonstrate that components of the central region of the synaptonemal complex are already expressed in the mitotic region of the ovaries, localize close to centromeres, and promote de novo association of centromeres. Our results thus show that meiotic proteins and meiotic organization of centromeres, which are key features to ensure reductional segregation, are laid out in amplifying germ cells, before meiosis has started. PMID:24367278

  9. The seeds and the worms: Ludwik Fleck and the early history of germ theories.

    PubMed

    Brorson, Stig

    2006-01-01

    The Polish microbiologist and philosopher of science, Ludwik Fleck (1896-1961), was a pioneer in constructivist history and philosophy of science. Based on studies in the history of syphilis, Fleck hypothesized that many established scientific facts are linked, in their development, to pre-scientific "proto-ideas." In 1935, Fleck proposed that the history of germ theories could be approached through his thesis on proto-ideas. His proposal, however, remained little more than a vague suggestion and was never developed in further detail. This paper introduces the concept of proto-ideas and discusses the central epistemological and historiographical implications of Fleck's thesis. The Fleckian approach offers an attractive alternative to positivist reconstructions of the early history of germ theories and provides a useful framework for a deeper understanding of the sociocultural background of the development of modern knowledge of infection. PMID:16489277

  10. Male germ cell-specific expression of a novel Patched-domain containing gene Ptchd3

    SciTech Connect

    Fan Jun; Akabane, Hiroto; Zheng Xuehai [Department of Biological Sciences, Marshall University, Huntington, WV (United States); Zhou Xuan; Zhang Li; Liu Qiang; Zhang Yonglian [Shanghai Key Laboratory for Molecular Andrology, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Yang Jing [Columbus Children's Research Institute, Columbus, OH (United States); Department of Pediatrics, Ohio State University, OH (United States); Zhu Guozhang [Department of Biological Sciences, Marshall University, Huntington, WV (United States)], E-mail: zhu4@marshall.edu

    2007-11-23

    The Hedgehog (Hh) signaling pathway plays an important role in various biological processes, including pattern formation, cell fate determination, proliferation, and differentiation. Hh function is mediated through its membrane receptor Patched. Herein, we have characterized a novel Patched-domain containing gene Ptchd3 in mouse. Messenger RNA of Ptchd3 was exclusively detected in the testis, and existed in two isoforms Ptchd3a and Ptchd3b. The expression of these two mRNA isoforms was shown to be developmentally regulated in testes, and specifically found in male germ cells. Further analysis revealed that the Ptchd3 protein was located on the midpiece of mouse, rat and human sperm. Collectively, these results indicate that Ptchd3 is a novel male germ cell-specific gene and may be involved in the Hh signaling to regulate sperm development and/or sperm function.

  11. [Mediastinal Nonseminomatous Germ Cell Tumor with Sarcoid-like Reaction in the Regional Lymph Nodes].

    PubMed

    Hamada, Akira; Kanauchi, Naoki; Suzuki, Katsuyuki; Watanabe, Hikaru; Watanabe, Isamu

    2015-06-01

    A 26-year-old man was admitted because of an abnormal shadow on a chest roentgenogram. Computed tomography(CT) revealed a very large tumor in the anterior mediastinum and bilateral mediastinal lymphadenopathy. Examination of a CT-guided biopsy specimen revealed a yolk-sac tumor. The patient received 4 courses of bleomycin, etoposide, and cisplatin chemotherapy. After chemotherapy, the tumor was markedly reduced in size, but the lymphadenopathy remained. The patient underwent thoracoscopic biopsy of the mediastinal lymph nodes. Sarcoid nodules were found in all the biopsied nodes, and the lymphadenopathy was thought to be a sarcoid-like reaction associated with the germ cell tumor. Resection of the residual tumor was performed according to the treatment algorithm of the International Germ Cell Cancer Collaborative Group. There were no viable tumor cells in the resected tissue. The patient is free of recurrence and without any sign of generalized sarcoidosis 3 years after the surgery. PMID:26066869

  12. A non-surgical approach for male germ cell mediated gene transmission through transgenesis

    PubMed Central

    Usmani, Abul; Ganguli, Nirmalya; Sarkar, Hironmoy; Dhup, Suveera; Batta, Suryaprakash R.; Vimal, Manoj; Ganguli, Nilanjana; Basu, Sayon; Nagarajan, P.; Majumdar, Subeer S.

    2013-01-01

    Microinjection of foreign DNA in male pronucleus by in-vitro embryo manipulation is difficult but remains the method of choice for generating transgenic animals. Other procedures, including retroviral and embryonic stem cell mediated transgenesis are equally complicated and have limitations. Although our previously reported technique of testicular transgenesis circumvented several limitations, it involved many steps, including surgery and hemicastration, which carried risk of infection and impotency. We improved this technique further, into a two step non-surgical electroporation procedure, for making transgenic mice. In this approach, transgene was delivered inside both testes by injection and modified parameters of electroporation were used for in-vivo gene integration in germ cells. Using variety of constructs, germ cell integration of the gene and its transmission in progeny was confirmed by PCR, slot blot and immunohistochemical analysis. This improved technique is efficient, requires substantially less time and can be easily adopted by various biomedical researchers. PMID:24305437

  13. Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary

    PubMed Central

    Wang, Zhengpin; Niu, Wanbao; Wang, Yijing; Teng, Zhen; Wen, Jia; Xia, Guoliang; Wang, Chao

    2015-01-01

    In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-? (TGF-?) family member activin (ACT) contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST), during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation. PMID:26076381

  14. A genome-wide association study of testicular germ cell tumor.

    PubMed

    Rapley, Elizabeth A; Turnbull, Clare; Al Olama, Ali Amin; Dermitzakis, Emmanouil T; Linger, Rachel; Huddart, Robert A; Renwick, Anthony; Hughes, Deborah; Hines, Sarah; Seal, Sheila; Morrison, Jonathan; Nsengimana, Jeremie; Deloukas, Panagiotis; Rahman, Nazneen; Bishop, D Timothy; Easton, Douglas F; Stratton, Michael R

    2009-07-01

    We conducted a genome-wide association study for testicular germ cell tumor (TGCT), genotyping 307,666 SNPs in 730 cases and 1,435 controls from the UK and replicating associations in a further 571 cases and 1,806 controls. We found strong evidence for susceptibility loci on chromosome 5 (per allele OR = 1.37 (95% CI = 1.19-1.58), P = 3 x 10(-13)), chromosome 6 (OR = 1.50 (95% CI = 1.28-1.75), P = 10(-13)) and chromosome 12 (OR = 2.55 (95% CI = 2.05-3.19), P = 10(-31)). KITLG, encoding the ligand for the receptor tyrosine kinase KIT, which has previously been implicated in the pathogenesis of TGCT and the biology of germ cells, may explain the association on chromosome 12. PMID:19483681

  15. A genome-wide association study of testicular germ cell tumor

    PubMed Central

    Rapley, Elizabeth A; Turnbull, Clare; Olama, Ali Amin Al; Dermitzakis, Emmanouil T; Linger, Rachel; Huddart, Robert A; Renwick, Anthony; Hughes, Deborah; Hines, Sarah; Seal, Sheila; Morrison, Jonathan; Nsengimana, Jeremie; Deloukas, Panagiotis; Rahman, Nazneen; Bishop, D Timothy; Easton, Douglas F; Stratton, Michael R

    2010-01-01

    We conducted a genome-wide association study for testicular germ cell tumor (TGCT), genotyping 307,666 SNPs in 730 cases and 1,435 controls from the UK and replicating associations in a further 571 cases and 1,806 controls. We found strong evidence for susceptibility loci on chromosome 5 (per allele OR = 1.37 (95% CI = 1.19–1.58), P = 3 × 10?13), chromosome 6 (OR = 1.50 (95% = CI = 1.28–1.75), P = 10?13) and chromosome 12 (OR = 2.55 (95% CI = 2.05–3.19), P = 10?31). KITLG, encoding the ligand for the receptor tyrosine kinase KIT, which has previously been implicated in the pathogenesis of TGCT and the biology of germ cells, may explain the association on chromosome 12. PMID:19483681

  16. Caenorhabditis Nematodes as a Model for the Adaptive Evolution of Germ Cells

    PubMed Central

    Haag, Eric S.

    2010-01-01

    A number of major adaptations in animals have been mediated by alteration of germ cells and their immediate derivatives, the gametes. Here, several such cases are discussed, including examples from echinoderms, vertebrates, insects, and nematodes. A feature of germ cells that make their development (and hence evolution) distinct from the soma is the prominent role played by post-transcriptional controls of mRNA translation in the regulation of proliferation and differentiation. This presents a number of special challenges for investigation of the evolution of germline development. Caenorhabditis nematodes represent a particularly favorable system for addressing these challenges, both because of technical advantages and (most importantly) because of natural variation in mating system that is rooted in alterations of germline sex determination. Recent studies that employ comparative genetic methods in this rapidly maturing system are discussed, and likely areas for future progress are identified. PMID:19361689

  17. Efficient germ-line transmission obtained with transgene-free induced pluripotent stem cells

    PubMed Central

    Wu, Sen; Wu, Yuanyuan; Zhang, Xi; Capecchi, Mario R.

    2014-01-01

    Induced pluripotent stem (iPS) cells hold great promise for regenerative medicine. To overcome potential problems associated with transgene insertions, efforts have been directed over the past several years to generate transgene-free iPS cells by using non-viral-vector approaches. To date, however, cells generated through such procedures have had problems producing reproductively competent animals, suggesting that their quality needed further improvement. Here we report the use of optimized assemblies of reprogramming factors and selection markers incorporated into single plasmids as nonintegrating episomes to generate germ-line–competent iPS cells. In particular, the pMaster12 episome can produce transgene-free iPS cells that, when grown in 2i medium, recapitulate good mouse ES cells, in terms of their competency for generating germ-line chimeras. PMID:25002522

  18. The Transcriptome and DNA Methylome Landscapes of Human Primordial Germ Cells.

    PubMed

    Guo, Fan; Yan, Liying; Guo, Hongshan; Li, Lin; Hu, Boqiang; Zhao, Yangyu; Yong, Jun; Hu, Yuqiong; Wang, Xiaoye; Wei, Yuan; Wang, Wei; Li, Rong; Yan, Jie; Zhi, Xu; Zhang, Yan; Jin, Hongyan; Zhang, Wenxin; Hou, Yu; Zhu, Ping; Li, Jingyun; Zhang, Ling; Liu, Sirui; Ren, Yixin; Zhu, Xiaohui; Wen, Lu; Gao, Yi Qin; Tang, Fuchou; Qiao, Jie

    2015-06-01

    Germ cells are vital for transmitting genetic information from one generation to the next and for maintaining the continuation of species. Here, we analyze the transcriptome of human primordial germ cells (PGCs) from the migrating stage to the gonadal stage at single-cell and single-base resolutions. Human PGCs show unique transcription patterns involving the simultaneous expression of both pluripotency genes and germline-specific genes, with a subset of them displaying developmental-stage-specific features. Furthermore, we analyze the DNA methylome of human PGCs and find global demethylation of their genomes. Approximately 10 to 11 weeks after gestation, the PGCs are nearly devoid of any DNA methylation, with only 7.8% and 6.0% of the median methylation levels in male and female PGCs, respectively. Our work paves the way toward deciphering the complex epigenetic reprogramming of the germline with the aim of restoring totipotency in fertilized oocytes. PMID:26046443

  19. Early depletion of primordial germ cells in zebrafish promotes testis formation.

    PubMed

    Tzung, Keh-Weei; Goto, Rie; Saju, Jolly M; Sreenivasan, Rajini; Saito, Taiju; Arai, Katsutoshi; Yamaha, Etsuro; Hossain, Mohammad Sorowar; Calvert, Meredith E K; Orbán, László

    2015-01-13

    As complete absence of germ cells leads to sterile males in zebrafish, we explored the relationship between primordial germ cell (PGC) number and sexual development. Our results revealed dimorphic proliferation of PGCs in the early zebrafish larvae, marking the beginning of sexual differentiation. We applied morpholino-based gene knockdown and cell transplantation strategies to demonstrate that a threshold number of PGCs is required for the stability of ovarian fate. Using histology and transcriptomic analyses, we determined that zebrafish gonads are in a meiotic ovarian stage at 14 days postfertilization and identified signaling pathways supporting meiotic oocyte differentiation and eventual female fate. The development of PGC-depleted gonads appears to be restrained and delayed, suggesting that PGC number may directly regulate the variability and length of gonadal transformation and testicular differentiation in zebrafish. We propose that gonadal transformation may function as a developmental buffering mechanism to ensure the reproductive outcome. PMID:25434820

  20. Primordial germ cell specification: a context-dependent cellular differentiation event [corrected].

    PubMed

    Günesdogan, Ufuk; Magnúsdóttir, Erna; Surani, M Azim

    2014-12-01

    During embryonic development, the foundation of the germline is laid by the specification of primordial germ cells (PGCs) from the postimplantation epiblast via bone morphogenetic protein (BMP) and WNT signalling. While the majority of epiblast cells undergo differentiation towards somatic cell lineages, PGCs initiate a unique cellular programme driven by the cooperation of the transcription factors BLIMP1, PRDM14 and AP2?. These factors synergistically suppress the ongoing somatic differentiation and drive the re-expression of pluripotency and germ cell-specific genes accompanied by global epigenetic changes. However, an unresolved question is how postimplantation epiblast cells acquire the developmental competence for the PGC fate downstream of BMP/WNT signalling. One emerging concept is that transcriptional enhancers might play a central role in the establishment of developmental competence and the execution of cell fate determination. Here, we discuss recent advances on the specification and reprogramming of PGCs thereby highlighting the concept of enhancer function. PMID:25349452

  1. Primoridal germ cell specification: a context-dependent cellular differentiation event

    PubMed Central

    Günesdogan, Ufuk; Magnúsdóttir, Erna; Surani, M. Azim

    2014-01-01

    During embryonic development, the foundation of the germline is laid by the specification of primordial germ cells (PGCs) from the postimplantation epiblast via bone morphogenetic protein (BMP) and WNT signalling. While the majority of epiblast cells undergo differentiation towards somatic cell lineages, PGCs initiate a unique cellular programme driven by the cooperation of the transcription factors BLIMP1, PRDM14 and AP2?. These factors synergistically suppress the ongoing somatic differentiation and drive the re-expression of pluripotency and germ cell-specific genes accompanied by global epigenetic changes. However, an unresolved question is how postimplantation epiblast cells acquire the developmental competence for the PGC fate downstream of BMP/WNT signalling. One emerging concept is that transcriptional enhancers might play a central role in the establishment of developmental competence and the execution of cell fate determination. Here, we discuss recent advances on the specification and reprogramming of PGCs thereby highlighting the concept of enhancer function. PMID:25349452

  2. Spata22, a Novel Vertebrate-Specific Gene, Is Required for Meiotic Progress in Mouse Germ Cells1

    PubMed Central

    La Salle, Sophie; Palmer, Kristina; O'Brien, Marilyn; Schimenti, John C.; Eppig, John; Handel, Mary Ann

    2011-01-01

    ABSTRACT The N-ethyl-N-nitrosourea-induced repro42 mutation, identified by a forward genetics strategy, causes both male and female infertility, with no other apparent phenotypes. Positional cloning led to the discovery of a nonsense mutation in Spata22, a hitherto uncharacterized gene conserved among bony vertebrates. Expression of both transcript and protein is restricted predominantly to germ cells of both sexes. Germ cells of repro42 mutant mice express Spata22 transcript, but not SPATA22 protein. Gametogenesis is profoundly affected by the mutation, and germ cells in repro42 mutant mice do not progress beyond early meiotic prophase, with subsequent germ cell loss in both males and females. The Spata22 gene is essential for one or more key events of early meiotic prophase, as homologous chromosomes of mutant germ cells do not achieve normal synapsis or repair meiotic DNA double-strand breaks. The repro42 mutation thus identifies a novel mammalian germ cell-specific gene required for meiotic progression. PMID:22011390

  3. Differentiation of human umbilical cord mesenchymal stem cells into germ-like cells in mouse seminiferous tubules

    PubMed Central

    CHEN, HUI; TANG, QIU-LING; WU, XIAO-YING; XIE, LI-CHUN; LIN, LI-MIN; HO, GU-YU; MA, LIAN

    2015-01-01

    Our previous study demonstrated that human umbilical cord mesenchymal stem cells (HUMSCs) were capable of differentiation into germ cells in vitro. To assess this potential in vivo, HUMSCs were microinjected into the lumen of seminiferous tubules of immunocompetent mice, which were treated with busulfan to destroy endogenous spermatogenesis. Bromodeoxyuridine labeling studies demonstrated that HUMSCs survived in the tubule for at least 120 days, exhibited a round cell shape typical of proliferating or differentiating germ cells, migrated to the basement of the tubule, where proliferating spermatogonia reside and returned to the luminal compartment, where differentiating spermatids and spermatozoa reside. The migration pattern resembled that of germ cell development in vivo. Immunohistochemical and colocalization studies revealed that transplanted HUMSCs expressed the germ cell markers octamer-binding transcription factor 4, ?6 integrin, C-kit and VASA, confirming the germ cell differentiation. In addition, it was observed that tubules transplanted with HUMSCs exhibited marked improvement in the histological features damaged by the chemotherapeutic busulfan, as judged by morphology and quantitative histology. Taken together, these data demonstrated the capacity of HUMSCs to form germ cells in the testes and to repair testicular tissue. These findings suggest a potential utility of HUMSCs to treat the infertility and testicular insufficiency caused by cancer therapeutics. PMID:25815600

  4. Prostaglandin D2 acts through the Dp2 receptor to influence male germ cell differentiation in the foetal mouse testis.

    PubMed

    Moniot, Brigitte; Ujjan, Safdar; Champagne, Julien; Hirai, Hiroyuki; Aritake, Kosuke; Nagata, Kinya; Dubois, Emeric; Nidelet, Sabine; Nakamura, Masataka; Urade, Yoshihiro; Poulat, Francis; Boizet-Bonhoure, Brigitte

    2014-09-01

    Through intercellular signalling, the somatic compartment of the foetal testis is able to program primordial germ cells to undergo spermatogenesis. Fibroblast growth factor 9 and several members of the transforming growth factor ? superfamily are involved in this process in the foetal testis, counteracting the induction of meiosis by retinoic acid and activating germinal mitotic arrest. Here, using in vitro and in vivo approaches, we show that prostaglandin D2 (PGD2), which is produced through both L-Pgds and H-Pgds enzymatic activities in the somatic and germ cell compartments of the foetal testis, plays a role in mitotic arrest in male germ cells by activating the expression and nuclear localization of the CDK inhibitor p21(Cip1) and by repressing pluripotency markers. We show that PGD2 acts through its Dp2 receptor, at least in part through direct effects in germ cells, and contributes to the proper differentiation of male germ cells through the upregulation of the master gene Nanos2. Our data identify PGD2 signalling as an early pathway that acts in both paracrine and autocrine manners, and contributes to the differentiation of germ cells in the foetal testis. PMID:25142465

  5. Reproductive Toxicity of Endosulfan: Implication From Germ Cell Apoptosis Modulated by Mitochondrial Dysfunction and Genotoxic Response Genes in Caenorhabditis elegans.

    PubMed

    Du, Hua; Wang, Meimei; Wang, Lei; Dai, Hui; Wang, Min; Hong, Wei; Nie, Xinxin; Wu, Lijun; Xu, An

    2015-05-01

    Endosulfan as a new member of persistent organic pollutants has been shown to induce reproductive dysfunction in various animal models. However, the action mechanism of endosulfan-produced reproductive toxicity remains largely unknown. This study was focused on investigating the reproductive toxicity induced by ?-endosulfan and clarifying the role of mitochondria and genotoxic response genes in germ cell apoptosis of Caenorhabditis elegans. Our data showed that endosulfan induced a dose-dependent decrease of life span, fecundity, and hatchability, whereas the germ cell apoptosis was dose-dependently increased. The mitochondria membrane potential was disrupted by endosulfan, leading to a significant increase of germ cell apoptosis in mev-1(kn-1) mutant. However, the apoptotic effects of endosulfan were blocked in mutants of cep-1(w40), egl-1(n487), and hus-1(op241), indicating conserved genotoxic response genes played an essential role in endosulfan-induced germ cell apoptosis. Furthermore, exposure to endosulfan induced the accumulation of HUS-1::GFP foci and the germ cell cycle arrest. These findings provided clear evidence that endosulfan caused significant adverse effects on the reproduction system of C. elegans and increased germ cell apoptosis, which was regulated by mitochondrial dysfunction and DNA damage response genes. This study may help to understand the signal transduction pathways involved in endosulfan-induced reproductive toxicity. PMID:25666835

  6. Computer-generated Three-dimensional Reconstruction of the Male Germ Unit of Rye (Secale cereale)

    NSDL National Science Digital Library

    H. Lloyd Mogensen (Northern Arizona University ADR; POSTAL)

    2004-03-09

    Computer-generated three-dimensional reconstruction of the male germ unit of rye (Secale cereale) based upon serial ultrathin sections. The two elongated sperm cells are connected at one end and each contains some plastids (green), as well as numerous mitochondria (red) and a nucleus (blue). The vegetative nucleus (blue) is closely associated with the sperm cells, but not connected; it contains a single nucleolus (white).

  7. Molecular cloning and expression of dead end homologue in chicken primordial germ cells

    Microsoft Academic Search

    Shinya Aramaki; Fuminori Sato; Takako Kato; Tomoki Soh; Yukio Kato; Masa-aki Hattori

    2007-01-01

    Chicken primordial germ cells (PGCs) dynamically migrate towards the prospective gonadal area through the germinal crescent\\u000a region and bloodstream at early embryonic stages. To date, chicken PGCs have been mainly identified by histochemical and immunohistochemical\\u000a methods or by their morphological characteristics. However, their origin, migration and differentiation are not fully understood\\u000a because of the lack of specific PGC molecular markers.

  8. Detection and characterization of primordial germ cells in pheasant ( Phasianus colchicus) embryos

    Microsoft Academic Search

    Jin Nam Kim; Young Mok Lee; Tae Sub Park; Jin Gyoung Jung; Byeong Wook Cho; Jeong Mook Lim; Jae Yong Han

    2005-01-01

    The developmental similarity between the chicken and pheasant (Phasianus colchicus) allows the novel biotechnologies developed in the chicken to be applied to the production of transgenic pheasants and interspecies germline chimeras. To detect pheasant primordial germ cells (PGCs) efficiently, which is important for inducing germline transmission, the ultrastructure of PGCs and their reactivity to several antibodies (2C9, QB2, anti-SSEA-1, and

  9. Formation of germ-line chimaeras from embryo-derived teratocarcinoma cell lines

    Microsoft Academic Search

    Allan Bradley; Martin Evans; Matthew H. Kaufman; Elizabeth Robertson

    1984-01-01

    The recent availability in culture of embryo-derived pluripotential cells which exhibit both a normal karyotype and a high differentiative ability1-3 has encouraged us to assess the potential of these cells to form functional germ cells following their incorporation into chimaeric mice. We report here the results of blastocyst injection studies using three independently isolated XY embryo-derived cell lines (EK.CP1, EK.CC1.1

  10. Analysis of the gene expression profile of mouse male meiotic germ cells

    Microsoft Academic Search

    Pellegrino Rossi; Susanna Dolci; Claudio Sette; Federica Capolunghi; Manuela Pellegrini; Maria Loiarro; Silvia Di Agostino; Maria Paola Paronetto; Paola Grimaldi; Daniele Merico; Enzo Martegani; Raffaele Geremia

    2004-01-01

    Wide genome analysis of difference in gene expression between spermatogonial populations from 7-day-old mice and pachytene spermatocytes from 18-day-old mice was performed using Affymetrix gene chips representing ?12,500 mouse known genes or EST sequences, spanning approximately 1\\/3rd of the mouse genome. To delineate differences in the profile of gene expression between mitotic and meiotic stages of male germ cell differentiation,

  11. Effects of the steel gene product on mouse primordial germ cells in culture

    Microsoft Academic Search

    I. Godin; R. Deed; J. Cooke; K. Zsebo; M. Dexter; C. C. Wylie

    1991-01-01

    MUTATIONS at the steel (si) and dominant white spotting (W) loci in the mouse affect primordial germ cells (PGC), melanoblasts and haemopoietic stem cells1. The W gene encodes a cell-surface receptor of the tyrosine kinase family2,3, the proto-oncogene c-kit. In situ analysis has shown c-kitmessenger RNA expression in PGC in the early genital ridges4. The SI gene encodes the ligand

  12. Feeding Deterrents and Sensitivity Suppressors for Pieris rapae Larvae in Wheat Germ Diet

    Microsoft Academic Search

    Xin Pei Huang; J. A. A. Renwick

    1997-01-01

    Rejection of wheat germ diet by cabbage-reared Pieris rapae larvae is explained by the fact that the diet contains strong feeding deterrents to the larvae. These deterrents were present mainly in hexane and butanol (BuOH) fractions of diet extracts, but the post-BuOH water fraction also showed some deterrent activity. Although minor diet components such as sorbic acid had a weak

  13. Sex Reversal in Zebrafish fancl Mutants Is Caused by Tp53-Mediated Germ Cell Apoptosis

    PubMed Central

    Rodríguez-Marí, Adriana; Cañestro, Cristian; BreMiller, Ruth A.; Nguyen-Johnson, Alexandria; Asakawa, Kazuhide; Kawakami, Koichi; Postlethwait, John H.

    2010-01-01

    The molecular genetic mechanisms of sex determination are not known for most vertebrates, including zebrafish. We identified a mutation in the zebrafish fancl gene that causes homozygous mutants to develop as fertile males due to female-to-male sex reversal. Fancl is a member of the Fanconi Anemia/BRCA DNA repair pathway. Experiments showed that zebrafish fancl was expressed in developing germ cells in bipotential gonads at the critical time of sexual fate determination. Caspase-3 immunoassays revealed increased germ cell apoptosis in fancl mutants that compromised oocyte survival. In the absence of oocytes surviving through meiosis, somatic cells of mutant gonads did not maintain expression of the ovary gene cyp19a1a and did not down-regulate expression of the early testis gene amh; consequently, gonads masculinized and became testes. Remarkably, results showed that the introduction of a tp53 (p53) mutation into fancl mutants rescued the sex-reversal phenotype by reducing germ cell apoptosis and, thus, allowed fancl mutants to become fertile females. Our results show that Fancl function is not essential for spermatogonia and oogonia to become sperm or mature oocytes, but instead suggest that Fancl function is involved in the survival of developing oocytes through meiosis. This work reveals that Tp53-mediated germ cell apoptosis induces sex reversal after the mutation of a DNA–repair pathway gene by compromising the survival of oocytes and suggests the existence of an oocyte-derived signal that biases gonad fate towards the female developmental pathway and thereby controls zebrafish sex determination. PMID:20661450

  14. Intracranial mixed germ cell tumor with syncytiotrophoblastic giant cells and precocious puberty

    Microsoft Academic Search

    A. Aguzzi; C. E. Hedinger; P. Kleihues; M. G. Ya?argil

    1988-01-01

    A 9-year-old male patient developed a germ cell tumor in the right basal ganglia which secretedß-human chorionic gonadotropin (ß-HCG) and caused precocious puberty. Histology and immunohistochemical staining for placental alkaline phosphatase (PLAP), a-fetoprotein (a-FP), andß-HCG showed a mixed population of neoplastic germinocytes, embryonal carcinoma, and syncytiotrophoblastic giant cells (STGC). Immunohistochemical double-staining for a-FP andß-HCG revealed that these two markers were

  15. Should We Treat The Human Germ-Line as A Global Human Resource?

    Microsoft Academic Search

    Eric T. Juengst

    \\u000a The flashpoint for most current international discussions of policies to govern genetic engineering is the question of whether\\u000a or not to allow scientists to pursue “germ-line gene therapy”: genetic engineering interventions that would effect changes\\u000a in people that would be passed along to their offspring as a natural part of their genetic inheritance. The question of whether\\u000a to proceed with

  16. Differentiation and Neuro-Protective Properties of Immortalized Human Tooth Germ Stem Cells

    Microsoft Academic Search

    Mehmet E. Yalvaç; Aysu Yilmaz; Dilek Mercan; Safa Aydin; Aysegul Dogan; Ahmet Arslan; Zeynel Demir; Ilnur I. Salafutdinov; Aygul K. Shafigullina; Fikrettin Sahin; Albert A. Rizvanov; András Palotás

    Stem cells are considered to be promising therapeutic options in many neuro-degenerative diseases and injuries to the central\\u000a nervous system, including brain ischemia and spinal cord trauma. Apart from the gold standard embryonic and mesenchymal origin,\\u000a human tooth germ stem cells (hTGSCs) have also been shown to enjoy the characteristics of mesenchymal stem cells (MSCs) and\\u000a the ability to differentiate

  17. BMP Signaling in the Human Fetal Ovary is Developmentally Regulated and Promotes Primordial Germ Cell Apoptosis

    PubMed Central

    Childs, Andrew J; Kinnell, Hazel L; Collins, Craig S; Hogg, Kirsten; Bayne, Rosemary AL; Green, Samira J; McNeilly, Alan S; Anderson, Richard A

    2010-01-01

    Primordial germ cells (PGCs) are the embryonic precursors of gametes in the adult organism, and their development, differentiation, and survival are regulated by a combination of growth factors collectively known as the germ cell niche. Although many candidate niche components have been identified through studies on mouse PGCs, the growth factor composition of the human PGC niche has not been studied extensively. Here we report a detailed analysis of the expression of components of the bone morphogenetic protein (BMP) signaling apparatus in the human fetal ovary, from postmigratory PGC proliferation to the onset of primordial follicle formation. We find developmentally regulated and reciprocal patterns of expression of BMP2 and BMP4 and identify germ cells to be the exclusive targets of ovarian BMP signaling. By establishing long-term cultures of human fetal ovaries in which PGCs are retained within their physiological niche, we find that BMP4 negatively regulates postmigratory PGC numbers in the human fetal ovary by promoting PGC apoptosis. Finally, we report expression of both muscle segment homeobox (MSX)1 and MSX2 in the human fetal ovary and reveal a selective upregulation of MSX2 expression in human fetal ovary in response to BMP4, suggesting this gene may act as a downstream effector of BMP-induced apoptosis in the ovary, as in other systems. These data reveal for the first time growth factor regulation of human PGC development in a physiologically relevant context and have significant implications for the development of cultures systems for the in vitro maturation of germ cells, and their derivation from pluripotent stem cells. PMID:20506112

  18. Sensitivity of spore germination and germ tube elongation of Saccharina japonica to metal exposure

    Microsoft Academic Search

    Taejun Han; Jeong-Ae Kong; Hee-Gyu Kang; Seon-Jin Kim; Gyo-Sun Jin; Hoon Choi; Murray T. Brown

    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.\\u000a The two endpoints used were spore germination and germ tube elongation with an exposure time of 24 h. Optimal test conditions\\u000a determined for photon irradiance, pH, salinity and

  19. Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish.

    PubMed

    Wildner, Daniel Dantas; Grier, Harry; Quagio-Grassiotto, Irani

    2013-03-01

    The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event. PMID:23317762

  20. Clinical Significance of Amyloid Precursor Protein in Patients with Testicular Germ Cell Tumor

    PubMed Central

    Yamada, Yuta; Fujimura, Tetsuya; Takahashi, Satoru; Takayama, Kenichi; Urano, Tomohiko; Murata, Taro; Obinata, Daisuke; Ouchi, Yasuyoshi; Homma, Yukio; Inoue, Satoshi

    2013-01-01

    Introduction. The biological role of amyloid precursor protein (APP) is not well understood, especially in testicular germ cell tumors (TGCTs). Therefore, we aimed to investigate the immunoreactivity (IR) and expression of APP in TGCTs and evaluated its clinical relevance. Materials and Methods. We performed an analysis of immunohistochemistry and mRNA expression of APP in 64 testicular specimens and 21 snap-frozen samples obtained from 1985 to 2004. We then evaluated the association between APP expression and clinicopathological status in TGCTs. Results. Positive APP IR was observed in 9.8% (4/41) of seminomatous germ cell tumors (SGCTs) and 39.1% (9/23) of nonseminomatous germ cell tumors (NGCTs). NGCTs showed significantly more cases of positive IR (P = 0.00870) and a higher mRNA expression level compared with those of SGCTs (P = 0.0140). Positive APP IR was also significantly associated with ?-fetoprotein (?FP) elevation (P = 0.00870) and venous invasion (P = 0.0414). Conclusion. We observed an elevated APP expression in TGCTs, especially in NGCTs. APP may be associated with a more aggressive cancer in TGCTs. PMID:23662100

  1. Specific repertoire of olfactory receptor genes in the male germ cells of several mammalian species

    SciTech Connect

    Vanderhaeghen, P.; Schurmans, S.; Vassart, G.; Parmentier, M. [Universite Libre de Bruxelles (Belgium)] [Universite Libre de Bruxelles (Belgium)

    1997-02-01

    Olfactory receptors constitute the largest family among G protein-coupled receptors, with up to 1000 members expected. We have previously shown that genes belonging to this family were expressed in the male germ line from both dog and human. We have subsequently demonstrated the presence of one of the corresponding olfactory receptor proteins during dog spermatogenesis and in mature sperm cells. In this study, we investigated whether the unexpected pattern of expression of olfactory receptors in the male germ line was conserved in other mammalian species. Using reverse transcription-PCR with primers specific for the olfactory receptor gene family, about 20 olfactory receptor cDNA fragments were cloned from the testis of each mammalian species tested. As a whole, they displayed no sequence specificity compared to other olfactory receptors, but highly homologous, possibly orthologous, genes were amplified from different species. Finally, their pattern of expression, as determined by RNase protection assay, revealed that many but not all of these receptors were expressed predominantly in testis. The male germ line from each mammalian species tested is thus characterized by a specific repertoire of olfactory receptors, which display a pattern of expression suggestive of their potential implication in the control of sperm maturation, migration, or fertilization. 34 refs., 4 figs., 1 tab.

  2. Ribosome Synthesis and MAPK Activity Modulate Ionizing Radiation-Induced Germ Cell Apoptosis in Caenorhabditis elegans

    PubMed Central

    Eberhard, Ralf; Stergiou, Lilli; Hofmann, E. Randal; Hofmann, Jen; Haenni, Simon; Teo, Youjin; Furger, André; Hengartner, Michael O.

    2013-01-01

    Synthesis of ribosomal RNA by RNA polymerase I (RNA pol I) is an elemental biological process and is key for cellular homeostasis. In a forward genetic screen in C. elegans designed to identify DNA damage-response factors, we isolated a point mutation of RNA pol I, rpoa-2(op259), that leads to altered rRNA synthesis and a concomitant resistance to ionizing radiation (IR)-induced germ cell apoptosis. This weak apoptotic IR response could be phenocopied when interfering with other factors of ribosome synthesis. Surprisingly, despite their resistance to DNA damage, rpoa-2(op259) mutants present a normal CEP-1/p53 response to IR and increased basal CEP-1 activity under normal growth conditions. In parallel, rpoa-2(op259) leads to reduced Ras/MAPK pathway activity, which is required for germ cell progression and physiological germ cell death. Ras/MAPK gain-of-function conditions could rescue the IR response defect in rpoa-2(op259), pointing to a function for Ras/MAPK in modulating DNA damage-induced apoptosis downstream of CEP-1. Our data demonstrate that a single point mutation in an RNA pol I subunit can interfere with multiple key signalling pathways. Ribosome synthesis and growth-factor signalling are perturbed in many cancer cells; such an interplay between basic cellular processes and signalling might be critical for how tumours evolve or respond to treatment. PMID:24278030

  3. Critical role of germ tube formation in the pathogenesis of candidal vaginitis.

    PubMed Central

    Sobel, J D; Muller, G; Buckley, H R

    1984-01-01

    A variant strain of Candida albicans incapable of hyphal production at 37 degrees C was used to study the role of germ tube formation in the pathogenesis of experimental vaginal candidiasis in rats. No difference was observed in the in vitro adherence at 25 degrees C of blastoconidia of the variant strain to vaginal epithelial cells when compared with the parent wild-type, germ tube-producing strain and multiple clinical isolates of C. albicans. However, after exposure to conditions favoring germ tube production, the adherence of the variant strain to epithelial cells was significantly less than that of germinated strains (P less than 0.01). In vivo animal studies revealed that the variant strain was less likely to result in vaginal colonization and infection than the wild-type strain and the other clinical isolates. Furthermore, infection, when established, was milder, often transient, and with significantly lower titers of cultured vaginal microorganisms obtained by lavage. Electron microscopic studies confirmed the failure of the variant strain to produce hyphae in vivo. The capacity of C. albicans to produce hyphae appears to be an important but nonessential virulence factor in the pathogenesis of candidal vaginitis. Images PMID:6327527

  4. Cytotoxic and genotoxic effects of methotrexate in germ cells of male Swiss mice.

    PubMed

    Padmanabhan, S; Tripathi, D N; Vikram, A; Ramarao, P; Jena, G B

    2008-01-01

    Methotrexate (MTX) is an anti-metabolite drug widely used in the treatment of neoplastic disorders, rheumatoid arthritis and psoriasis. Developed as an analogue of folic acid, it inhibits purine and pyrimidine synthesis that accounts for its therapeutic efficacy as well as for its toxicities. MTX has narrow therapeutic index and its toxicity has been reported in various organ systems including gastrointestinal, haematologic and central nervous system. The objective of the present study is to investigate the germ cell toxicity induced by MTX in male Swiss mice. MTX was administered intraperitoneally (ip) at the doses of 5, 10, 20 and 40 mg/kg to mice (20-25 g) weekly once (wk) for 5 and 10 weeks. The animals were sacrificed 1 week after receiving the last treatment of MTX. The germ cell toxicity was evaluated using testes weight (wt), sperm count, sperm head morphology, sperm comet assay, histology, TUNEL and halo assay in testis. MTX treatment significantly reduced the sperm count and increased the occurrence of sperm head abnormalities in a dose dependent manner. It induced the testicular toxicity as evident from the histology of testis. Sperm comet, TUNEL and halo assay in testis also revealed significant DNA damage after MTX treatment. On the basis of the present study, it can be concluded that MTX induced germ cell toxicity in mice. PMID:18678279

  5. It's All in Your Mind: Determining Germ Cell Fate by Neuronal IRE-1 in C. elegans

    PubMed Central

    Levi-Ferber, Mor; Salzberg, Yehuda; Safra, Modi; Haviv-Chesner, Anat; Bülow, Hannes E.; Henis-Korenblit, Sivan

    2014-01-01

    The C. elegans germline is pluripotent and mitotic, similar to self-renewing mammalian tissues. Apoptosis is triggered as part of the normal oogenesis program, and is increased in response to various stresses. Here, we examined the effect of endoplasmic reticulum (ER) stress on apoptosis in the C. elegans germline. We demonstrate that pharmacological or genetic induction of ER stress enhances germline apoptosis. This process is mediated by the ER stress response sensor IRE-1, but is independent of its canonical downstream target XBP-1. We further demonstrate that ire-1-dependent apoptosis in the germline requires both CEP-1/p53 and the same canonical apoptotic genes as DNA damage-induced germline apoptosis. Strikingly, we find that activation of ire-1, specifically in the ASI neurons, but not in germ cells, is sufficient to induce apoptosis in the germline. This implies that ER stress related germline apoptosis can be determined at the organism level, and is a result of active IRE-1 signaling in neurons. Altogether, our findings uncover ire-1 as a novel cell non-autonomous regulator of germ cell apoptosis, linking ER homeostasis in sensory neurons and germ cell fate. PMID:25340700

  6. Induction of mouse germ-cell fate by transcription factors in vitro.

    PubMed

    Nakaki, Fumio; Hayashi, Katsuhiko; Ohta, Hiroshi; Kurimoto, Kazuki; Yabuta, Yukihiro; Saitou, Mitinori

    2013-09-12

    The germ-cell lineage ensures the continuity of life through the generation of male and female gametes, which unite to form a totipotent zygote. We have previously demonstrated that, by using cytokines, embryonic stem cells and induced pluripotent stem cells can be induced into epiblast-like cells (EpiLCs) and then into primordial germ cell (PGC)-like cells with the capacity for both spermatogenesis and oogenesis, creating an opportunity for understanding and regulating mammalian germ-cell development in both sexes in vitro. Here we show that, without cytokines, simultaneous overexpression of three transcription factors, Blimp1 (also known as Prdm1), Prdm14 and Tfap2c (also known as AP2?), directs EpiLCs, but not embryonic stem cells, swiftly and efficiently into a PGC state. Notably, Prdm14 alone, but not Blimp1 or Tfap2c, suffices for the induction of the PGC state in EpiLCs. The transcription-factor-induced PGC state, irrespective of the transcription factors used, reconstitutes key transcriptome and epigenetic reprogramming in PGCs, but bypasses a mesodermal program that accompanies PGC or PGC-like-cell specification by cytokines including bone morphogenetic protein 4. Notably, the transcription-factor-induced PGC-like cells contribute to spermatogenesis and fertile offspring. Our findings provide a new insight into the transcriptional logic for PGC specification, and create a foundation for the transcription-factor-based reconstitution and regulation of mammalian gametogenesis. PMID:23913270

  7. Production of human CD59-transgenic pigs by embryonic germ cell nuclear transfer

    SciTech Connect

    Ahn, Kwang Sung; Won, Ji Young [Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of)] [Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of); Park, Jin-Ki [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of)] [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of); Sorrell, Alice M. [Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of)] [Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of); Heo, Soon Young; Kang, Jee Hyun [Department of Nanobiomedical Science, Dankook University, Cheonan (Korea, Republic of)] [Department of Nanobiomedical Science, Dankook University, Cheonan (Korea, Republic of); Woo, Jae-Seok [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of)] [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of); Choi, Bong-Hwan [Genomics and Bioinformatics Division, National Institute of Animal Science, Suwon (Korea, Republic of)] [Genomics and Bioinformatics Division, National Institute of Animal Science, Suwon (Korea, Republic of); Chang, Won-Kyong [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of)] [Animal Biotechnology Division, National Institute of Animal Science, Suwon (Korea, Republic of); Shim, Hosup, E-mail: shim@dku.edu [Department of Nanobiomedical Science, Dankook University, Cheonan (Korea, Republic of) [Department of Nanobiomedical Science, Dankook University, Cheonan (Korea, Republic of); Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of)

    2010-10-01

    Research highlights: {yields} Human CD59 (hCD59) gene was introduced into porcine embryonic germ (EG) cells. {yields} hCD59-transgenic EG cells were resistant to hyperacute rejection in cytolytic assay. {yields} hCD59-transgenic pigs were produced by EG cell nuclear transfer. -- Abstract: This study was performed to produce transgenic pigs expressing the human complement regulatory protein CD59 (hCD59) using the nuclear transfer (NT) of embryonic germ (EG) cells, which are undifferentiated stem cells derived from primordial germ cells. Because EG cells can be cultured indefinitely in an undifferentiated state, they may provide an inexhaustible source of nuclear donor cells for NT to produce transgenic pigs. A total of 1980 NT embryos derived from hCD59-transgenic EG cells were transferred to ten recipients, resulting in the birth of fifteen piglets from three pregnancies. Among these offspring, ten were alive without overt health problems. Based on PCR analysis, all fifteen piglets were confirmed as hCD59 transgenic. The expression of the hCD59 transgene in the ten living piglets was verified by RT-PCR. Western analysis showed the expression of the hCD59 protein in four of the ten RT-PCR-positive piglets. These results demonstrate that hCD59-transgenic pigs could effectively be produced by EG cell NT and that such transgenic pigs may be used as organ donors in pig-to-human xenotransplantation.

  8. Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

    PubMed Central

    Lee, Sang-Kon; Park, Sungman; Gimm, Yoon-Myoung; Kim, Yoon-Won

    2014-01-01

    The energy generated by an extremely low frequency electromagnetic field (ELF-EMF) is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF) is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010) for limiting exposure to time-varying MF (1?Hz to 100?kHz), overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF. PMID:25025060

  9. Processing in layer 4 of the neocortical circuit: new insights from visual and somatosensory cortex

    Microsoft Academic Search

    Kenneth D Miller; David J Pinto; Daniel J Simons

    2001-01-01

    Recent experimental and theoretical results in cat primary visual cortex and in the whisker-barrel fields of rodent primary somatosensory cortex suggest common organizing principles for layer 4, the primary recipient of sensory input from the thalamus. Response tuning of layer 4 cells is largely determined by a local interplay of feed-forward excitation (directly from the thalamus) and inhibition (from layer

  10. Genome-wide analysis of germ cell proliferation in C. elegans identifies VRK-1 as a key regulator of CEP-1/p53

    PubMed Central

    Waters, Katherine; Yang, Alison Z.; Reinke, Valerie

    2012-01-01

    Proliferating germ cells in Caenorhabditis elegans provide a useful model system for deciphering fundamental mechanisms underlying the balance between proliferation and differentiation. Using gene expression profiling, we identified approximately 200 genes upregulated in the proliferating germ cells of C. elegans. Functional characterization using RNA-mediated interference demonstrated that over forty of these factors are required for normal germline proliferation and development. Detailed analysis of two of these factors defined an important regulatory relationship controlling germ cell proliferation. We established that the kinase VRK-1 is required for normal germ cell proliferation, and that it acts in part to regulate CEP-1(p53) activity. Loss of cep-1 significantly rescued the proliferation defects of vrk-1 mutants. We suggest that VRK-1 prevents CEP-1 from triggering an inappropriate cell cycle arrest, thereby promoting germ cell proliferation. This finding reveals a previously unsuspected mechanism for negative regulation of p53 activity in germ cells to control proliferation. PMID:20599896

  11. Germ-line origins of mutation in families with hemophilia B: The sex ratio varies with the type of mutation

    SciTech Connect

    Ketterling, R.P.; Vielhaber, E.; Bottema, C.D.K.; Schaid, D.J.; Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States)); Cohen, M.P. (Vanderbilt Univ., Nashville, TN (United States)); Sexauer, C.L. (Children's Hospital, Oklahoma City, OK (United States))

    1993-01-01

    Previous epidemiological and biochemical studies have generated conflicting estimates of the sex ratio of mutation. Direct genomic sequencing in combination with haplotype analysis extends previous analyses by allowing the precise mutation to be determined in a given family. From analysis of the factor IX gene of 260 consecutive families with hemophilia B, the authors report the germ-line origin of mutation in 25 families. When combined with 14 origins of mutation reported by others and with 4 origins previously reported by them, a total of 25 occur in the female germ line, and 18 occur in the male germ line. The excess of germ-line origins in females does not imply an overall excess mutation rate per base pair in the female germ line. Bayesian analysis of the data indicates that the sex ratio varies with the type of mutation. The aggregate of single-base substitutions shows a male predominance of germ-line mutations (P < .002). The maximum-likelihood estimate of the male predominance is 3.5-fold. Of the single-base substitutions, deletions display a sex ratio of unity. Analysis of the parental age at transmission of a new mutation suggests that germ-line mutations are associated with a small increase in parental age in females but little, if any, increase in males. Although direct genomic sequencing offers a general method for defining the origin of mutation in specific families, accurate estimates of the sex ratios of different mutational classes require large sample sizes and careful correction for multiple biases of ascertainment. The biases in the present data result in an underestimate of the enhancement of mutation in males. 62 refs., 1 fig., 5 tabs.

  12. [Primary hyperparathyroidism].

    PubMed

    Carnevale, V; Romagnoli, E; Pipino, M; Scillitani, A; D'Erasmo, E; Minisola, S; Mazzuoli, G

    2005-01-01

    Primary hyperparathyroidism (PHPT) is characterized by excessive PTH secretion in respect to calcium homeostasis needs, due to parathyroid adenoma (80% of cases), hyperplasia (15-20%), or carcinoma (1-2%). In familial forms of PHPT, several mutations have an established role: menin gene for MEN type 1, RET for MEN type 2a, calcium-sensing receptor gene for familial hypocalciuric hypercalcemia, parafibromin gene for PHPT-jaw tumour and carcinoma. Etiology of sporadic adenomas (80% of PHPT cases) is less defined, being most commonly found a mutation of menin gene or activation of PRAD1 oncogene. In recent years, the classical features of the disease became less common. Typically, bone involvement is now represented by a reduced bone mass at skeletal sites more rich in cortical tissue. Prominently trabecular skeletal sites are relatively spared, because of the anabolic effects of a slight PTH excess on trabecular tissue. PHPT patients may have increased fracture risk, though it is not clear why bone damage is more severe in a subgroup of patients. Clinical features of hypercalcemia may be fatigue, anorexia, thirst, and polyuria. Vague neurological and psychiatric symptoms, such as weakness, anxiety, depression, paresthesias, and muscular cramps may ameliorate after parathyroidectomy. Recent reports indicate increased cardiovascular mortality in PHPT patients. Diagnosis is based on the detection of hypercalcemia, together with inappropriately high serum PTH levels. Preoperative localization of the diseased glands is mandatory in persistent or recurrent PHPT, as like as when minimally invasive surgery is planned. High resolution ultrasonography and SPECT double-phase 99m Tc-sestamibi scintigraphy are the most commonly employed techniques. Intraoperatory PTH assay may confirm successful surgery when serum concentrations decrease more than 50%. Surgical therapy is indicated in patients with renal or skeletal complications, such as in those with previous parathyrotoxic crisis. Many surgeons in recent years adopted minimally invasive parathyroidectomy. Medical treatment is an option for patients unwilling or unfitted for surgery because of severe concomitant diseases. Employed therapy includes estrogens, SERMs, bisphosphonates and calcimimetics. PMID:16382970

  13. Mitotic arrest of female germ cells during prenatal oogenesis. A colcemid-like, non-apoptotic cell death.

    PubMed

    Wartenberg, H; Ihmer, A; Schwarz, S; Miething, A; Viebahn, C

    2001-11-01

    The sequence of events and a possible reason for germ cell death during oogenesis in the prenatal ovary were studied in rat and mouse embryos. ED 14-22 rat and ED 14-16 mouse embryos were studied using semithin sections for light microscopy and serial ultrathin sections for electron microscopy. In addition, the rat material was 3H-thymidine labelled for historadioautography and cytospin preparations of freshly obtained gonads were immunohistochemically analysed. During the transition from the proliferating oogonial stage to the meiotic prophase about 16% of the postmitotic oocytes do not pass the initial meiotic checkpoint on ED 18/19 in the rat (ED 15/16 in the mouse). These germ cells first show structural signs of mitosis; the diploid number of 'super-condensed' chromosomes are globally formed and are concentrated in the center of the cell. Although the germ cells show all morphological signs of living cells they never have mitotic spindles; the micro-tubulus-organisation-centres (MTOCs) are found peripherally and become concentrated, forming a single centrosomal body (acentriolar MTOC) as detected by immunohistochemistry for the centrosomal protein MPM2 and gamma-tubulin. EM studies show 25 nm tubule-like profiles within the MTOC bodies. The centrioles frequently lie separate from the MTOC material or are not present at all; the germ cells are apparently arrested in a prophase- or metaphase-like stage when they have reached the postmitotic G2/preleptotenal transition and are unable to enter meiosis. Forty-eight to 72 h after the first mitotically arrested germ cells are found, degeneration is seen in these germ cells. This second event, the germ cell death proper, shows neither criteria of apoptosis (cell shrinkage, marginal condensation of chromatin, DNA fragmentation) nor signs of necrosis (cell swelling, pycnosis, inflammation). Both arrested pro- and metaphase-like stages are found with signs of cell death and phagocytosis. The morphological signs of phagocytosis are found in neighbouring pregranulosa cells. The final heterocytotic bodies contain the remnants of the centrosomal (MTOC) material and DAPI-positive DNA material. The pregranulosa cells are mitotically silent during the phase when mitotic arrest and germ cell degeneration is found. The results suggest the presence of a hypothetical 'anti-spindle' factor, which under normal conditions is necessary for induction of meiotic prophase. The structural events of 'arrested mitosis' is reminiscent of those induced by the antimitotic, tubule-degrading drug colcemid. This type of arrest may inhibit meiosis of more than 33% prenatal germ cells and induce their cell death. PMID:11789990

  14. The P cytotype in Drosophila melanogaster: a maternally transmitted regulatory state of the germ line associated with telomeric P elements.

    PubMed Central

    Simmons, Michael J; Raymond, John D; Niemi, Jarad B; Stuart, Jeremy R; Merriman, Peter J

    2004-01-01

    The incomplete P elements TP5 and TP6 are inserted in the TAS repeats near the left telomere of the Drosophila melanogaster X chromosome. These telomeric P elements repress P-induced gonadal dysgenesis and germ-line hypermutability in both sexes. However, their capacity to repress hypermutability is lost when they are transmitted patroclinously in a cross. TP5 and TP6 do not repress P-element activity in somatic cells, nor do they alter the somatic or germ-line phenotypes of P-insertion alleles. In the germ line, these elements suppress the phenotype of a P-insertion allele of the singed gene that is evoked by other P elements, presumably because these other elements encode repressor polypeptides. This suppression is more effective when the telomeric P elements are inherited maternally. Regulation by telomeric P elements parallels that of the P cytotype, a state that represses P-element activity in some strains of Drosophila. This state exists only in the germ line and is maternally transmitted along with the P elements themselves. Regulation by known repressor P polypeptides is not restricted to the germ line and does not require maternal transmission of the relevant P elements. Regulation by telomeric P elements appears to be epistatic to regulation by repressor P polypeptides. PMID:15020422

  15. Removal of Polycomb Repressive Complex 2 makes C. elegans germ cells susceptible to direct conversion into specific somatic cell types

    PubMed Central

    Patel, Tulsi; Tursun, Baris; Rahe, Dylan P.; Hobert, Oliver

    2012-01-01

    How specific cell types can be directly converted into other distinct cell types is a matter of intense investigation with wide-ranging basic and biomedical implications. We show here that the removal of the histone 3 lysine 27 (H3K27) methyltransferase complex PRC2 (“Polycomb Repressor Complex 2”) permits ectopically expressed, neuron-type-specific transcription factors (“terminal selectors”) to convert C. elegans germ cells directly into specific neuron types. Terminal selector-induced germ cell-to-neuron conversion can not only be observed upon genome-wide loss of H3K27 methylation in PRC2(?) animals, but also upon genome-wide redistribution of H3K27 methylation patterns in animals which lack the H3K36 methyltransferase MES-4. Manipulation of the H3K27 methylation status not only permits conversion of germ cells into neurons, but also permits hlh-1/MyoD-dependent conversion of germ cells into muscle cells, indicating the PRC2 protects the germline from the aberrant execution of multiple distinct somatic differentiation programs. Taken together, our findings demonstrate that the normally multi-step process of development from a germ cell via a zygote to a terminally differentiated somatic cell type can be shortcut by providing an appropriate terminal selector transcription factor and manipulating histone methylation patterns. PMID:23103163

  16. Alleviative effect of quercetin on germ cells intoxicated by 3-methyl-4-nitrophenol from diesel exhaust particles*

    PubMed Central

    Bu, Tong-liang; Jia, Yu-dong; Lin, Jin-xing; Mi, Yu-ling; Zhang, Cai-qiao

    2012-01-01

    As a component of diesel exhaust particles, 3-methyl-4-nitrophenol (4-nitro-m-cresol, PNMC) is also a metabolite of the insecticide fenitrothion and imposes hazardous effects on human health. In the present study, the alleviative effect of a common antioxidant flavonoid quercetin on mouse germ cells intoxicated by PNMC was investigated. Results showed that a single intraperitoneal injection of PNMC at 100 mg/kg induced severe testicular damage after one week. PNMC-treated mice showed a significant loss of germ cells (approximate 40% loss of round germ cells). PNMC caused an increase of hydroxyl radical and hydrogen peroxide production and lipid peroxidation, as well as a decrease in glutathione level, superoxide dismutase and glutathione peroxidase activities. Furthermore, treatment of PNMC increased expression of the pro-apoptotic protein Bax and decreased expression of the anti-apoptotic protein Bcl-XL in germ cells. In addition, testicular caspase-3 activity was significantly up-regulated and germ cell apoptosis was significantly increased in the PNMC-treated mice. In contrast, combined administration of quercetin at 75 mg/kg significantly attenuated PNMC-induced testicular toxicity. These results indicate that the antioxidant quercetin displays a remarkable protective effect on PNMC-induced oxidative damage in mouse testes and may represent an efficient supplement to attenuate reproductive toxicity by environmental toxicants to ensure healthy sperm production. PMID:22467373

  17. Hypersensitivity of Primordial Germ Cells to Compromised Replication-Associated DNA Repair Involves ATM-p53-p21 Signaling

    PubMed Central

    Zeng, Ruizhu; Southard, Teresa L.; Shima, Naoko; Schimenti, John C.

    2014-01-01

    Genome maintenance in germ cells is critical for fertility and the stable propagation of species. While mechanisms of meiotic DNA repair and chromosome behavior are well-characterized, the same is not true for primordial germ cells (PGCs), which arise and propagate during very early stages of mammalian development. Fanconi anemia (FA), a genomic instability syndrome that includes hypogonadism and testicular failure phenotypes, is caused by mutations in genes encoding a complex of proteins involved in repair of DNA lesions associated with DNA replication. The signaling mechanisms underlying hypogonadism and testicular failure in FA patients or mouse models are unknown. We conducted genetic studies to show that hypogonadism of Fancm mutant mice is a result of reduced proliferation, but not apoptosis, of PGCs, resulting in reduced germ cells in neonates of both sexes. Progressive loss of germ cells in adult males also occurs, overlaid with an elevated level of meiotic DNA damage. Genetic studies indicated that ATM-p53-p21 signaling is partially responsible for the germ cell deficiency. PMID:25010009

  18. Surrogate production of eggs and sperm by intrapapillary transplantation of germ cells in cytoablated adult fish.

    PubMed

    Majhi, Sullip Kumar; Hattori, Ricardo Shohei; Rahman, Sheikh Mustafizur; Strüssmann, Carlos Augusto

    2014-01-01

    Germ cell transplantation (GCT) is a promising assisted reproductive technology for the conservation and propagation of endangered and valuable genetic resources. In teleost fish, GCT in adult gonads has been achieved only in male recipients, limiting greatly the usefulness of this technique in situations where both sexes need equal and timely attention for conservation and/or propagation. Here we describe a simplified GCT approach that ultimately leads to production of donor-derived eggs and sperm in considerably short time. Donor germ cells isolated from young pejerrey Odontesthes bonariensis (Atherinopsidae) were transplanted non-surgically through the genital papilla into the sexually mature gonads of Patagonian pejerrey O. hatcheri recipients whose gonads have been depleted of endogenous GCs by heat (26°C) and chemical treatment (four doses of Busulfan at 30 mg/kg and 40 mg/kg for females and males, respectively). Transplanted spermatogonial and oogonial cells were able to recolonize the recipients' gonads and produce functional donor origin eggs and sperm within 7 months from the GCT. We confirmed the presence of donor-derived gametes by PCR in 17% and 5% of the surrogate O. hatcheri fathers and mothers, respectively. The crosses between surrogate fathers and O. bonariensis mothers yielded 12.6-39.7% pure O. bonariensis and that between a surrogate mother and an O. bonariensis father yielded 52.2% pure O. bonariensis offspring. Our findings confirm that transplantation of germ cells into sexually competent adult fish by non-surgical methods allows the production of functional donor-derived eggs and sperm in a considerably short time. The methods described here could play a vital role in conservation and rapid propagation of endangered fish genetic resources. PMID:24748387

  19. Molecular and biological aspects of early germ cell development in interspecies hybrids between chickens and pheasants.

    PubMed

    Kang, Seok Jin; Sohn, Sea Hwan; Kang, Kyung Soo; Lee, Hyung Chul; Lee, Seul Ki; Choi, Jin Won; Han, Jae Yong

    2011-03-01

    Interspecific hybrids provide insights into fundamental genetic principles, and may prove useful for biotechnological applications and as tools for the conservation of endangered species. In the present study, interspecies hybrids were generated between the Korean ring-necked pheasant (Phasianus colchicus) and the White Leghorn chicken (Gallus gallus domesticus). We determined whether these hybrids were good recipients for the production of germline chimeric birds. PCR-based species-specific amplification and karyotype analyses showed that the hybrids inherited genetic material from both parents. Evaluation of biological function indicated that the growth rates of hybrids during the exponential phase (body weight/week) were similar to those of the pheasant but not the chicken, and that the incubation period for hatching was significantly different from that of both parents. Primordial germ cells (PGCs) of hybrids reacted with a pheasant PGC-specific antibody and circulated normally in blood vessels. The peak time of hybrid PGC migration was equivalent to that of the pheasant. In late embryonic stages, germ cells were detected by the QCR1 antibody on 15 d male gonads and were normally localized in the seminiferous cords. We examined the migration ability and developmental localization of exogenous PGCs transferred into the blood vessels of 63 h hybrid embryos. Donor-derived PGCs reacted with a donor-specific antibody were detected on 7 d gonads and the seminiferous tubules of hatchlings. Therefore, germ cell transfer into developing embryos of an interspecies hybrid can be efficiently used for the conservation of threatened animals and endangered species, and many biotechnological applications. PMID:21111472

  20. Analysis of the gene expression profile of mouse male meiotic germ cells.

    PubMed

    Rossi, Pellegrino; Dolci, Susanna; Sette, Claudio; Capolunghi, Federica; Pellegrini, Manuela; Loiarro, Maria; Di Agostino, Silvia; Paronetto, Maria Paola; Grimaldi, Paola; Merico, Daniele; Martegani, Enzo; Geremia, Raffaele

    2004-05-01

    Wide genome analysis of difference in gene expression between spermatogonial populations from 7-day-old mice and pachytene spermatocytes from 18-day-old mice was performed using Affymetrix gene chips representing approximately 12,500 mouse known genes or EST sequences, spanning approximately 1/3rd of the mouse genome. To delineate differences in the profile of gene expression between mitotic and meiotic stages of male germ cell differentiation, expressed genes were grouped in functional clusters. The analysis confirmed the previously described pre-meiotic or meiotic expression for several genes, in particular for those involved in the regulation of the mitotic and meiotic cell cycle, and for those whose transcripts are accumulated during the meiotic stages to be translated later in post-meiotic stages. Differential expression of several additional genes was discovered. In few cases (pro-apoptotic factors Bak, Bad and Bax), data were in conflict with the previously published stage-dependent expression of genes already known to be expressed in male germ cells. Northern blot analysis of selected genes confirmed the results obtained with the microarray chips. Six of these were novel genes specifically expressed in pachytene spermatocytes: a chromatin remodeling factor (chrac1/YCL1), a homeobox gene (hmx1), a novel G-coupled receptor for an unknown ligand (Gpr19), a glycoprotein of the intestinal epithelium (mucin 3), a novel RAS activator (Ranbp9), and the A630056B21Rik gene (predicted to encode a novel zinc finger protein). These studies will help to delineate the global patterns of gene expression characterizing male germ cell differentiation for a better understanding of regulation of spermatogenesis in mammals. PMID:15053975

  1. The ovo gene of Drosophila encodes a zinc finger protein required for female germ line development.

    PubMed Central

    Mével-Ninio, M; Terracol, R; Kafatos, F C

    1991-01-01

    As defined by dominant and recessive ovo mutations, the ovo gene is required for development of the Drosophila female germ line, and does not exert any function in males or in somatic tissues. However, reversion of dominant ovo mutations can result in new phenotypes that are not related to the female germ line: the svb and lzl mutations affect cuticle and eye development, respectively. We have identified a 7.2 kb genomic fragment that rescues ovo mutations in transgenic Drosophila and thus contains all sequences necessary for ovo+ function. This fragment has been sequenced almost in its entirety, defining the ovo locus at the molecular level. Multiple copies of the same fragment also rescue the lzl mutation. They do not rescue svb mutations, in agreement with genetic evidence that the svb function requires additional, more distal sequences. Nevertheless, a number of transposable element insertions that induce a svb phenotype interrupt the coding sequence of ovo. Taken together, the genetic and molecular data indicate the existence of a complex locus, where the ovo and svb functions depend on overlapping coding sequences but distinct regulatory elements. The data also suggest a model for the lzl phenotype. Expression of ovo at the RNA level is detectable at stage 8 of oogenesis in nurse cells and persists through the rest of oogenesis and in early embryogenesis. The ovo transcript encodes a protein of at least 1209 amino acids with four zinc fingers, suggesting that ovo might be a transcription factor required for female germ line maintenance and gametogenesis. Images PMID:1712294

  2. Surrogate Production of Eggs and Sperm by Intrapapillary Transplantation of Germ Cells in Cytoablated Adult Fish

    PubMed Central

    Majhi, Sullip Kumar; Hattori, Ricardo Shohei; Rahman, Sheikh Mustafizur; Strüssmann, Carlos Augusto

    2014-01-01

    Germ cell transplantation (GCT) is a promising assisted reproductive technology for the conservation and propagation of endangered and valuable genetic resources. In teleost fish, GCT in adult gonads has been achieved only in male recipients, limiting greatly the usefulness of this technique in situations where both sexes need equal and timely attention for conservation and/or propagation. Here we describe a simplified GCT approach that ultimately leads to production of donor-derived eggs and sperm in considerably short time. Donor germ cells isolated from young pejerrey Odontesthes bonariensis (Atherinopsidae) were transplanted non-surgically through the genital papilla into the sexually mature gonads of Patagonian pejerrey O. hatcheri recipients whose gonads have been depleted of endogenous GCs by heat (26°C) and chemical treatment (four doses of Busulfan at 30 mg/kg and 40 mg/kg for females and males, respectively). Transplanted spermatogonial and oogonial cells were able to recolonize the recipients' gonads and produce functional donor origin eggs and sperm within 7 months from the GCT. We confirmed the presence of donor-derived gametes by PCR in 17% and 5% of the surrogate O. hatcheri fathers and mothers, respectively. The crosses between surrogate fathers and O. bonariensis mothers yielded 12.6–39.7% pure O. bonariensis and that between a surrogate mother and an O. bonariensis father yielded 52.2% pure O. bonariensis offspring. Our findings confirm that transplantation of germ cells into sexually competent adult fish by non-surgical methods allows the production of functional donor-derived eggs and sperm in a considerably short time. The methods described here could play a vital role in conservation and rapid propagation of endangered fish genetic resources. PMID:24748387

  3. Bifocal intracranial tumors of nongerminomatous germ cell etiology: diagnostic and therapeutic implications

    PubMed Central

    Aizer, Ayal A.; Sethi, Roshan V.; Hedley-Whyte, E. Tessa; Ebb, David; Tarbell, Nancy J.; Yock, Torunn I.; MacDonald, Shannon M.

    2013-01-01

    Background Patients presenting with synchronous bifocal intracranial tumors (masses in the pineal and neurohypophyseal region), detectable human chorionic gonadotropin (hCG) levels (5–100 mIU/mL), and normal alpha feto-protein (AFP) levels (?10 ng/mL) are often diagnosed empirically with pure germinoma. In such scenarios, pathologic confirmation is often deferred, given that bifocal nongerminomatous germ cell tumors (NGGCTs) are considered rare and because available literature and research protocols support such an approach. We sought to characterize the association between bifocal intracranial tumors and NGGCT histology. Methods Seventy-one patients treated for intracranial germ cell tumors at Massachusetts General Hospital in 1998–2012 were identified. Patients presenting with synchronous bifocal disease were selected for further review. Results Of the 71 patients presenting with intracranial germ cell tumors, 14 (19.7%) had synchronous bifocal disease. Of these 14 patients, 7 (50.0%) had germinoma, 3 (21.4%) had NGGCT, and 4 (28.6%) had hCG levels <200 mIU/mL and normal AFP levels and were treated without pathologic confirmation. Of the 3 patients with confirmed bifocal NGGCT, 2 had detectable hCG levels with AFP <10 ng/mL and 1 patient had a detectable hCG level with a modest elevation in AFP. Conclusions NGGCTs should be considered in the differential diagnosis for patients presenting with bifocal intracranial tumors. Given differences in the management of germinomas and NGGCTs, clinicians should strongly consider a biopsy in patients presenting with bifocal masses and normal or modestly elevated biomarkers. Misclassification of such cases as germinomas could result in undertreatment and a possible increased risk for recurrence. PMID:23640532

  4. Maternal syntabulin is required for dorsal axis formation and is a germ plasm component in Xenopus.

    PubMed

    Colozza, Gabriele; De Robertis, Edward M

    2014-07-01

    In amphibians and teleosts, early embryonic axial development is driven by maternally deposited mRNAs and proteins, called dorsal determinants, which migrate to the presumptive dorsal side of the embryo in a microtubule-dependent manner after fertilization. Syntabulin is an adapter protein that binds to kinesin KIF5B and to the transmembrane protein Syntaxin1. In zebrafish, a mutation in Syntabulin causes complete embryo ventralization. It is unknown whether Syntabulin plays an analogous role during early development of other species, a question addressed here in Xenopus laevis. in situ hybridization of syntabulin mRNA was carried out at different stages of Xenopus development. In oocytes, syntabulin transcripts were localized to the vegetal cortex of large oocytes and the mitochondrial cloud of very young oocytes. We extended the zebrafish data by finding that during cleavage Xenopus syntabulin mRNA localized to the germ plasm and was later expressed in primordial germ cells (PGCs). This new finding suggested a role for Syntabulin during germ cell differentiation. The functional role of maternal syntabulin mRNA was investigated by knock-down with phosphorothioate DNA antisense oligos followed by oocyte transfer. The results showed that syntabulin mRNA depletion caused the complete loss of dorso-anterior axis formation in frog embryos. Consistent with the ventralized phenotype, syntabulin-depleted embryos displayed severe reduction of dorsal markers and ubiquitous transcription of the ventral marker sizzled. Syntabulin was required for the maternal Wnt/?-Catenin signal, since ventralization could be completely rescued by injection of ?-catenin (or syntabulin) mRNA. The data suggest an evolutionarily conserved role for Syntabulin, a protein that bridges microtubule motors and membrane vesicles, during dorso-ventral axis formation in the vertebrates. PMID:24798204

  5. High-frequency germ-line transmission of plasmid DNA sequences injected into fertilized zebrafish eggs.

    PubMed Central

    Culp, P; Nüsslein-Volhard, C; Hopkins, N

    1991-01-01

    With the goal of developing techniques for DNA insertional mutagenesis in zebrafish, we established procedures for rapidly obtaining and injecting large numbers of fertilized eggs. Using either of two plasmid constructs, we injected uncut DNA into fertilized eggs at the one- or two-cell stage. Fish hatched from injected eggs were raised to sexual maturity, and the frequency of transgenic founder fish was determined by pair-mating the fish and testing DNA extracted from pools of their 16-hr-old offspring by the polymerase chain reaction (PCR) and then Southern analysis. Eggs injected with one of two different plasmids yielded no transgenic fish, but 7-25% (19 of 115 overall) of the eggs injected with the other plasmid transmitted the injected sequences to their offspring (F1). Of seven lines studied further, all were able to pass the foreign DNA sequences to the next (F2) generation. Inheritance in the F2 generation was Mendelian in the five lines tested. PCR and Southern analysis indicated that the plasmid sequences were present in multiple copies, probably tandemly arranged. Two founder fish carried more than one independent integration of the plasmid sequences. The line studied in more detail was a mosaic carrying two independently segregating copies of the transgene in one germ cell and a third copy in another germ-line precursor cell. The ability to obtain and inject large numbers of zebrafish eggs combined with a high frequency of germ-line integration may be steps toward the goal of being able to perform insertional mutagenesis with this organism. Images PMID:1910170

  6. Delayed Effects of Whole Brain Radiotherapy in Germ Cell Tumor Patients With Central Nervous System Metastases

    SciTech Connect

    Doyle, Danielle M. [Department of Medicine, Division of Hematology and Oncology, Indiana University, Indianapolis, IN (United States); Walther Cancer Institute, Indianapolis, IN (United States)], E-mail: dpeoni@iupui.edu; Einhorn, Lawrence H. [Department of Medicine, Division of Hematology and Oncology, Indiana University, Indianapolis, IN (United States); Walther Cancer Institute, Indianapolis, IN (United States)

    2008-04-01

    Purpose: Central nervous system (CNS) metastases are uncommon in patients with germ cell tumors, with an incidence of 2-3%. CNS metastases have been managed with whole brain radiotherapy (WBRT) and concomitant cisplatin-based combination chemotherapy. Our previous study did not observe serious CNS toxicity (Int J Radiat Oncol Biol Phys 1991;22:17-22). We now report on 5 patients who developed delayed significant CNS toxicity. Patients and Methods: We observed 5 patients with delayed CNS toxicity. The initial diagnosis was between 1981 and 2003. All patients had poor-risk disease according to the International Germ Cell Consensus Collaborative Group criteria. Of the 5 patients, 3 had CNS metastases at diagnosis and 2 developed relapses with CNS metastases. These 5 patients underwent WBRT to 4,000-5,000 cGy in 18-28 fractions concurrently with cisplatin-based chemotherapy. Results: All 5 patients developed delayed symptoms consistent with progressive multifocal leukoencephalopathy. The symptoms included seizures, hemiparesis, cranial neuropathy, headaches, blindness, dementia, and ataxia. The median time from WBRT to CNS symptoms was 72 months (range, 9-228). Head imaging revealed multiple abnormalities consistent with gliosis and diffuse cerebral atrophy. Of the 5 patients, 3 had progressive and 2 stable symptoms. Treatment with surgery and/or steroids had modest benefit. The progressive multifocal leukoencephalopathy resulted in significant debility in all 5 patients, resulting in death (3 patients), loss of work, steroid-induced morbidity, and recurrent hospitalizations. Conclusion: Whole brain radiotherapy is not innocuous in young patients with germ cell tumors and can cause late CNS toxicity.

  7. Comparative Effects of Di(n-Butyl) Phthalate Exposure on Fetal Germ Cell Development in the Rat and in Human Fetal Testis Xenografts

    PubMed Central

    McKinnell, Chris; Calarrão, Ana; Kennedy, Laura; Hutchison, Gary R.; Hrabalkova, Lenka; Jobling, Matthew S.; Macpherson, Sheila; Anderson, Richard A.; Sharpe, Richard M.; Mitchell, Rod T.

    2014-01-01

    Background Phthalate exposure induces germ cell effects in the fetal rat testis. Although experimental models have shown that the human fetal testis is insensitive to the steroidogenic effects of phthalates, the effects on germ cells have been less explored. Objectives We sought to identify the effects of phthalate exposure on human fetal germ cells in a dynamic model and to establish whether the rat is an appropriate model for investigating such effects. Methods We used immunohistochemistry, immunofluorescence, and quantitative real-time polymerase chain reaction to examine Sertoli and germ cell markers on rat testes and human fetal testis xenografts after exposure to vehicle or di(n-butyl) phthalate (DBP). Our study included analysis of germ cell differentiation markers, proliferation markers, and cell adhesion proteins. Results In both rat and human fetal testes, DBP exposure induced similar germ cell effects, namely, germ cell loss (predominantly undifferentiated), induction of multinucleated gonocytes (MNGs), and aggregation of differentiated germ cells, although the latter occurred rarely in the human testes. The mechanism for germ cell aggregation and MNG induction appears to be loss of Sertoli cell–germ cell membrane adhesion, probably due to Sertoli cell microfilament redistribution. Conclusions Our findings provide the first comparison of DBP effects on germ cell number, differentiation, and aggregation in human testis xenografts and in vivo in rats. We observed comparable effects on germ cells in both species, but the effects in the human were muted compared with those in the rat. Nevertheless, phthalate effects on germ cells have potential implications for the next generation, which merits further study. Our results indicate that the rat is a human-relevant model in which to explore the mechanisms for germ cell effects. Citation van den Driesche S, McKinnell C, Calarrão A, Kennedy L, Hutchison GR, Hrabalkova L, Jobling MS, Macpherson S, Anderson RA, Sharpe RM, Mitchell RT. 2015. Comparative effects of di(n-butyl) phthalate exposure on fetal germ cell development in the rat and in human fetal testis xenografts. Environ Health Perspect 123:223–230;?http://dx.doi.org/10.1289/ehp.1408248 PMID:25514601

  8. Layered Liquids

    NSDL National Science Digital Library

    John Eichinger

    2009-05-30

    This activity involves an exploration of density. Why does oil float on water? How does drain cleaner sink down into the clogged pipe right through standing water? These questions will be answered as students make a layered "parfait" of colored liquids ba

  9. Retrograde and transganglionic transport of horseradish peroxidase-conjugated cholera toxin B subunit, wheatgerm agglutinin and isolectin B4 from Griffonia simplicifolia I in primary afferent neurons innervating the rat urinary bladder

    Microsoft Academic Search

    H. F Wang; P Shortland; M. J Park; G Grant

    1998-01-01

    In the present study, we investigated and compared the ability of the cholera toxin B subunit, wheat germ agglutinin and isolectin B4 from Griffonia simplicifolia I conjugated to horseradish peroxidase, to retrogradely and transganglionically label visceral primary afferents after unilateral injections into the rat urinary bladder wall. Horseradish peroxidase histochemical or lectin-immunofluorescence histochemical labelling of bladder afferents was seen in

  10. Cyclic AMP and c-KIT Signaling in Familial Testicular Germ Cell Tumor Predisposition

    PubMed Central

    Azevedo, Monalisa F.; Horvath, Anelia; Bornstein, Ethan R.; Almeida, Madson Q.; Xekouki, Paraskevi; Faucz, Fabio R.; Gourgari, Evgenia; Nadella, Kiran; Remmers, Elaine F.; Quezado, Martha; de Alexandre, Rodrigo Bertollo; Kratz, Christian P.; Nesterova, Maria; Greene, Mark H.

    2013-01-01

    Background: Familial testicular germ cell tumors (FTGCTs) are hypothesized to result from the combined interaction of multiple low-penetrance genes. We reported inactivating germline mutations of the cAMP-binding phosphodiesterase 11A (PDE11A) as modifiers of FTGCT risk. Recent genome-wide association studies have identified single-nucleotide polymorphisms in the KITLG gene, the ligand for the cKIT tyrosine kinase receptor, as strong modifiers of susceptibility to both familial and sporadic testicular germ cell tumors. Design: We studied 94 patients with FTGCTs and 50 at-risk male relatives from 63 unrelated kindreds, in whom the PDE11A gene had been sequenced by investigating the association between KITLG genome-wide association study single-nucleotide polymorphisms rs3782179 and rs4474514 and FTGCT risk in these patients and in 692 controls. We also examined cAMP and c-KIT signaling in testicular tissues and cell lines and extended the studies to 2 sporadic cases, one with a PDE11A defect and one without, as a comparison. Results: We found a higher frequency of the KITLG risk alleles in FTGCT patients who also had a PDE11A sequence variant, compared with those with a wild-type PDE11A sequence. In NTERA-2 and Tcam-2 cells transfected with the mutated forms of PDE11A (R52T, F258Y, Y727C, R804H, V820M, R867G, and M878V), cAMP levels were significantly higher, and the relative phosphodiesterase activity was lower than in the wild-type cells. KITLG expression was consistently increased in the presence of PDE11A-inactivating defects, both at the RNA and protein levels, in familial testicular germ cell tumors. The 2 sporadic cases that were studied, one with a PDE11A defect and another without, agreed with the data in FTGTCT and in the cell lines. Conclusions: Patients with FTGCT and PDE11A defects also carry KITLG risk alleles more frequently. There may be an interaction between cAMP and c-KIT signaling in predisposition to testicular germ cell tumors. PMID:23771924

  11. [Positron emission tomography in the diagnosis and monitoring of patients with nonseminomatous germ cell tumours].

    PubMed

    Büchler, T; Simonová, K; Fencl, P; Abrahámová, J

    2011-01-01

    The role of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis and monitoring of nonseminomatous germ cell tumours is currently unclear. Clinical studies have suggested that FDG-PET has relatively low sensitivity and specificity in the setting of initial staging and viability assessment of post-chemotherapy residual lesions. On the other hand, FDG-PET provides potentially useful information in patients with elevated tumour markers and/or multiple residual lesions with limited resectability. Other possible indications of FDG-PET are the early assessment of tumour chemosensitivity and the diagnosis of inflammatory treatment complications. PMID:22257229

  12. Appearance pattern of tooth germs with developmental process in Mylopharyngodon piceus

    NASA Astrophysics Data System (ADS)

    Yue, Pei-Qi; Nakajima, Tsuneo

    1995-06-01

    The pharyngeal dental formula of Mylopharyngodon piceus is 4 5 as a rule, and the dentition is asymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearance pattern of tooth germ with development process in this fish is described in detail. The formation pattern of the left dentition is contrasted with that of the right one. In the developmental process, the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designated by Nakajima (1984), while the right one is A-type.

  13. The effects of growth factors on testicular germ cell apoptosis in the stallion

    E-print Network

    Donnelly, Casey Leanne

    2002-01-01

    /growth factors such as interleukin-1 alpha (IL-1 cr) and IL- 6, nerve growth factor beta (NGFP), epidermal growth factor (EGF), fibroblast growth factor alpha (FGFct), FGFP, insulin-like growth factor I (IGF-I), IGF-II, and fete calf serum (FCS) on germ cell... in maintaining spermatogenesis, and FGF influences cellular growth and differentiation in spermatogenesis. Insulin-like growth factor and NGF are both highly expressed in the testes. Mouse spermatocytes and early spermatids secrete and express NGF. Insulin...

  14. Germ-line transgenesis of the Tc1/mariner superfamily transposon Minos in Ciona intestinalis

    PubMed Central

    Sasakura, Yasunori; Awazu, Satoko; Chiba, Shota; Satoh, Nori

    2003-01-01

    The tadpole larva of the basal chordate Ciona intestinalis has the most simplified, basic body-plan of chordates. Because it has a compact genome with a complete draft sequence, a large quantity of EST/cDNA information, and a short generation time, Ciona is a suitable model for future genetics. We establish here a transgenic technique in Ciona that uses the Tc1/mariner superfamily transposon Minos. Minos was integrated efficiently into the genome of germ cells and transmitted stably to subsequent generations. In addition, an enhancer-trap line was obtained. This is a demonstration of efficient, Minos-mediated transgenesis in marine invertebrates. PMID:12788975

  15. Phosphorylation of wheat germ initiation factor 2 (eIF-2) by N-ethylmaleimide-treated wheat germ lysates and by purified casein kinase II does not affect the guanine nucleotide exchange on eIF-2.

    PubMed

    Janaki, N; Krishna, V M; Ramaiah, K V

    1995-12-01

    Phosphorylation of the small subunit of eukaryotic initiation factor-2 (eIF-2 alpha) impairs protein synthesis in mammalian systems. It is not known, however, if a similar regulatory mechanism exists in plants. Previous reports indicate that one of the wheat germ eIF-2 subunits, the p40-41 doublet, is phosphorylated by heterologous eIF-2 alpha kinases. Here we report that phosphorylation of the small subunit in wheat germ eIF-2, p36, occurs in translating wheat germ lysates which are pretreated with N-ethylmaleimide (NEM) and dithiothreitol. Also, a purified sea star casein kinase II (CKII) phosphorylates the p41-42 doublet and p36 subunits of wheat germ eIF-2. While heme-regulated eIF-2 alpha kinase from reticulocyte lysates does not inhibit wheat germ protein synthesis, CKII and NEM are found to be inhibitory. To determine whether phosphorylation of the small subunit (p36) is the cause for protein synthesis inhibition, we have further studied the exchange of labeled GDP for unlabeled GDP in the preformed eIF-2. [3H]GDP complex in vitro in the presence of CKII and ATP. The GDP exchange in eIF-2.GDP complex can occur without the addition of any protein factor and the exchange reaction is marginally inhibited by CKII. A 0-70% ammonium sulfate cut fraction, prepared from NEM-treated wheat germ lysate, also does not inhibit the guanine nucleotide exchange reaction. These findings suggest that the protein synthesis inhibition in these cases is not mediated by eIF-2 phosphorylation. PMID:7503542

  16. Expression of BLIMP1/PRMT5 and concurrent histone H2A/H4 arginine 3 dimethylation in fetal germ cells, CIS/IGCNU and germ cell tumors

    PubMed Central

    Eckert, Dawid; Biermann, Katharina; Nettersheim, Daniel; Gillis, Ad JM; Steger, Klaus; Jäck, Hans-Martin; Müller, Annette M; Looijenga, Leendert HJ; Schorle, Hubert

    2008-01-01

    Background Most testicular germ cell tumors arise from intratubular germ cell neoplasia unclassified (IGCNU, also referred to as carcinoma in situ), which is thought to originate from a transformed primordial germ cell (PGC)/gonocyte, the fetal germ cell. Analyses of the molecular profile of IGCNU and seminoma show similarities to the expression profile of fetal germ cells/gonocytes. In murine PGCs, expression and interaction of Blimp1 and Prmt5 results in arginine 3 dimethylation of histone H2A and H4. This imposes epigenetic modifications leading to transcriptional repression in mouse PGCs enabling them to escape the somatic differentiation program during migration, while expressing markers of pluripotency. Results In the present study, we show that BLIMP1 and PRMT5 were expressed and arginine dimethylation of histones H2A and H4 was detected in human male gonocytes at weeks 12–19 of gestation, indicating a role of this mechanism in human fetal germ cell development as well. Moreover, BLIMP1/PRMT5 and histone H2A and H4 arginine 3 dimethylation was present in IGCNU and most seminomas, while downregulated in embryonal carcinoma (EC) and other nonseminomatous tumors. Conclusion These data reveal similarities in marker expression and histone modification between murine and human PGCs. Moreover, we speculate that the histone H2A and H4 arginine 3 dimethylation might be the mechanism by which IGCNU and seminoma maintain the undifferentiated state while loss of these histone modifications leads to somatic differentiation observed in nonseminomatous tumors. PMID:18992153

  17. Stirred suspension bioreactors as a novel method to enrich germ cells from pre-pubertal pig testis.

    PubMed

    Dores, C; Rancourt, D; Dobrinski, I

    2015-05-01

    To study spermatogonial stem cells the heterogeneous testicular cell population first needs to be enriched for undifferentiated spermatogonia, which contain the stem cell population. When working with non-rodent models, this step requires working with large numbers of cells. Available cell separation methods rely on differential properties of testicular cell types such as expression of specific cell surface proteins, size, density, or differential adhesion to substrates to separate germ cells from somatic cells. The objective of this study was to develop an approach that allowed germ cell enrichment while providing efficiency of handling large cell numbers. Here, we report the use of stirred suspension bioreactors (SSB) to exploit the adhesion properties of Sertoli cells to enrich cells obtained from pre-pubertal porcine testes for undifferentiated spermatogonia. We also compared the bioreactor approach with an established differential plating method and the combination of both: SSB followed by differential plating. After 66 h of culture, germ cell enrichment in SSBs provided 7.3 ± 1.0-fold (n = 9), differential plating 9.8 ± 2.4-fold (n = 6) and combination of both methods resulted in 9.1 ± 0.3-fold enrichment of germ cells from the initial germ cell population (n = 3). To document functionality of cells recovered from the bioreactor, we demonstrated that cells retained their functional ability to reassemble seminiferous tubules de novo after grafting to mouse hosts and to support spermatogenesis. These results demonstrate that the SSB allows enrichment of germ cells in a controlled and scalable environment providing an efficient method when handling large cell numbers while reducing variability owing to handling. PMID:25877677

  18. C. elegans pro-1 activity is required for soma\\/germline interactions that influence proliferation and differentiation in the germ line

    Microsoft Academic Search

    Darrell J. Killian; E. Jane; Albert Hubbard

    2004-01-01

    Strict spatial and temporal regulation of proliferation and differentiation is essential for proper germline development and often involves soma\\/germline interactions. In C. elegans, a particularly striking outcome of defective regulation of the proliferation\\/differentiation pattern is the Pro phenotype in which an ectopic mass of proliferating germ cells occupies the proximal adult germ line, a region normally occupied by gametes. We

  19. Germ cell depletion does not alter the morphogenesis of the fetal testis or ovary in the red-eared slider turtle (Trachemys scripta)

    Microsoft Academic Search

    Leo Dinapoli; Blanche Capel

    2007-01-01

    In the red-eared slider turtle, Trachemys scripta, both prospective male and female gonads contain primitive cord structures at the time when the gonad first forms. Primordial germ cells arrive in the gonad and accumulate on the coelomic surface. If testis development is initiated, these cords develop further at the same time that germ cells migrate from the coelomic surface and

  20. Journal of Coastal Research 24 4 10081021 West Palm Beach, Florida July 2008 A Tale of Germs, Storms, and Bombs: Geomorphology and

    E-print Network

    , Storms, and Bombs: Geomorphology and Coral Assemblage Structure at Vieques (Puerto Rico) Compared to St.P.; WALKER, B.K.; KOHLER, K.; GILLIAM, D., and DODGE, R.E., 2008. A tale of germs, storms, and bombs but not quantitatively discernible at our scale of sampling. Germs and storms, rather than bombs (and associated naval

  1. EGO-1 is related to RNA-directed RNA polymerase and functions in germ-line development and RNA interference in C. elegans

    E-print Network

    Maine, Eleanor

    developmental pathways. For example, germ cells in the nematode worm Caenorhabditis elegans choose between to RNA-mediated genetic silencing (also called RNA interference or RNAi) in C. elegans (see [13,14]). Rd indeed insensitive or weakly sensitive to RNAi in the expression of some, but not all, germ

  2. Isolation and characterization of stem cells derived from human third molar tooth germs of young adults: implications in neo-vascularization, osteo-, adipo- and neurogenesis

    Microsoft Academic Search

    M E Yalvac; M Ramazanoglu; A A Rizvanov; F Sahin; O F Bayrak; U Salli; A Palotás; G T Kose

    2010-01-01

    A number of studies have reported in the last decade that human tooth germs contain multipotent cells that give rise to dental and peri-odontal structures. The dental pulp, third molars in particular, have been shown to be a significant stem cell source. In this study, we isolated and characterized human tooth germ stem cells (hTGSCs) from third molars and assessed

  3. hH-Rev107, a class II tumor suppressor gene, is expressed by post-meiotic testicular germ cells and CIS cells

    E-print Network

    Paris-Sud XI, Université de

    1 hH-Rev107, a class II tumor suppressor gene, is expressed by post-meiotic testicular germ cells and CIS cells but not by human testicular germ cell tumors Sylvie Siegrist1 , Chloé Féral1 , Mounia Chami1@im3.inserm.fr Running title: hH-Rev107 in human testicular cancer Keywords: hH-Rev107; tumor

  4. Polar Layers

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02153 Polar Layers

    This image of the south polar region shows layered material. It is not known if the layers are formed yearly or if they form over the period of 10s to 100s of years or more.

    Image information: VIS instrument. Latitude -80.3N, Longitude 296.2E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. N-cadherin expression in malignant germ cell tumours of the testis

    PubMed Central

    2012-01-01

    Background Testicular germ cell tumours (TGCTs) are the most common malignancy in young men aged 18–35 years. They are clinically and histologically subdivided into seminomas and non-seminomas. Cadherins are calcium-dependent transmembrane proteins of the group of adhesion proteins. They play a role in the stabilization of cell-cell contacts, the embryonic morphogenesis, in the maintenance of cell polarity and signal transduction. N-cadherin (CDH2), the neuronal cadherin, stimulates cell-cell contacts during migration and invasion of cells and is able to suppress tumour cell growth. Methods Tumour tissues were acquired from 113 male patients and investigated by immunohistochemistry, as were the three TGCT cell lines NCCIT, NTERA-2 and Tcam2. A monoclonal antibody against N-cadherin was used. Results Tumour-free testis and intratubular germ cell neoplasias (unclassified) (IGCNU) strongly expressed N-cadherin within the cytoplasm. In all seminomas investigated, N-cadherin expression displayed a membrane-bound location. In addition, the teratomas and yolk sac tumours investigated also differentially expressed N-cadherin. In contrast, no N-cadherin could be detected in any of the embryonal carcinomas and chorionic carcinomas examined. This expression pattern was also seen in the investigated mixed tumours consisting of seminomas, teratomas, and embryonal carcinoma. Conclusions N-cadherin expression can be used to differentiate embryonal carcinomas and chorionic carcinomas from other histological subtypes of TGCT. PMID:23066729

  6. Oocyte formation by mitotically-active germ cells purified from ovaries of reproductive age women

    PubMed Central

    White, Yvonne A. R.; Woods, Dori C.; Takai, Yasushi; Ishihara, Osamu; Seki, Hiroyuki; Tilly, Jonathan L.

    2012-01-01

    Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a FACS-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically-active cells that exhibit a gene expression profile consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and spontaneously generate 35–50 µm oocytes, as determined by morphology, gene expression and attainment of haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1–2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, like adult mice, possess rare mitotically-active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo. PMID:22366948

  7. Expression of Syndecan-4 and Correlation with Metastatic Potential in Testicular Germ Cell Tumours

    PubMed Central

    Labropoulou, Vassiliki T.; Skandalis, Spyros S.; Ravazoula, Panagiota; Perimenis, Petros; Karamanos, Nikos K.; Kalofonos, Haralabos P.; Theocharis, Achilleas D.

    2013-01-01

    Although syndecan-4 is implicated in cancer progression, there is no information for its role in testicular germ cell tumours (TGCTs). Thus, we examined the expression of syndecan-4 in patients with TGCTs and its correlation with the clinicopathological findings. Immunohistochemical staining in 71 tissue specimens and mRNA analysis revealed significant overexpression of syndecan-4 in TGCTs. In seminomas, high percentage of tumour cells exhibited membranous and/or cytoplasmic staining for syndecan-4 in all cases. Stromal staining for syndecan-4 was found in seminomas and it was associated with nodal metastasis (P = 0.04), vascular/lymphatic invasion (P = 0.01), and disease stage (P = 0.04). Reduced tumour cell associated staining for syndecan-4 was observed in nonseminomatous germ cell tumours (NSGCTs) compared to seminomas. This loss of syndecan-4 was associated with nodal metastasis (P = 0.01), vascular/lymphatic invasion (P = 0.01), and disease stage (P = 0.01). Stromal staining for syndecan-4 in NSGCTs did not correlate with any of the clinicopathological variables. The stromal expression of syndecan-4 in TGCTs was correlated with microvessel density (P = 0.03). Our results indicate that syndecan-4 is differentially expressed in seminomas and NSGCTs and might be a useful marker. Stromal staining in seminomas and reduced levels of syndecan-4 in tumour cells in NSGCTs are related to metastatic potential, whereas stromal staining in TGCTs is associated with neovascularization. PMID:23844358

  8. Germ cell transplantation in felids: a potential approach to preserving endangered species.

    PubMed

    Silva, Robson C; Costa, Guilherme M J; Lacerda, Samyra M S N; Batlouni, Sérgio R; Soares, Jaqueline M; Avelar, Gleide F; Böttger, Karin B; Silva, Silvério F; Nogueira, Maria S; Andrade, Leonardo M; França, Luiz R

    2012-01-01

    With the exception of the domestic cat, all members of the family Felidae are considered either endangered or threatened. Although not yet used for this purpose, spermatogonial stem cell (SSC) transplantation has a high potential to preserve the genetic stock of endangered species. However, this technique has not previously been established in felids. Therefore, we developed the necessary procedures to perform syngeneic and xenogeneic SSC transplants (eg, germ cell [GC] depletion in the recipient domestic cats, enrichment and labeling of donor cell suspension, and the transplantation method) in order to investigate the feasibility of the domestic cat as a recipient for the preservation and propagation of male germ plasm from wild felids. In comparison with busulfan treatment, local x-ray fractionated radiation was a more effective approach to depleting endogenous spermatogenesis. The results of both syngeneic and xenogeneic transplants revealed that SSCs were able to successfully colonize and differentiate in the recipient testis, generating elongated spermatids several weeks posttransplantation. Specifically, ocelot spermatozoa were observed in the cat epididymis 13 weeks following transplantation. As donor GCs from domestic cats and ocelots were able to develop and form mature GCs in the recipient environment seminiferous tubules, these findings indicate that the domestic cat is a suitable recipient for SSC transplantation. Moreover, as modern cats descended from a medium-size cat that existed approximately 10 to 11 million years ago, these results strongly suggest that the domestic cat could be potentially used as a recipient for generating and propagating the genome of wild felids. PMID:21597091

  9. HELQ promotes RAD51 paralog-dependent repair to avert germ cell attrition and tumourigenesis

    PubMed Central

    Adelman, Carrie A.; Lolo, Rafal L.; Birkbak, Nicolai J.; Murina, Olga; Matsuzaki, Kenichiro; Horejsi, Zuzana; Parmar, Kalindi; Borel, Valérie; Skehel, J. Mark; Stamp, Gordon; D’Andrea, Alan; Sartori, Alessandro A.; Swanton, Charles; Boulton, Simon J.

    2013-01-01

    Repair of interstrand crosslinks (ICLs) requires the coordinate action of the intra-S phase checkpoint and the Fanconi Anemia (FA) pathway, which promote ICL incision, translesion synthesis, and homologous recombination (reviewed in 1,2). Previous studies have implicated the 3?-5? superfamily 2 helicase HELQ/Hel308 in ICL repair in D. melanogaster (known as Mus301 or Spn-C3) and C. elegans (known as Helq-1 or Hel-3084). While in vitro analysis suggests that HELQ preferentially unwinds synthetic replication fork substrates with 3? ssDNA overhangs and also disrupts protein/DNA interactions while translocating along DNA5,6, little is known regarding its functions in mammalian organisms. Here we report that HELQ helicase-deficient mice exhibit subfertility, germ cell attrition, ICL sensitivity and tumour predisposition, with HelQ heterozygous mice exhibiting a similar, albeit less severe, phenotype than the null, indicative of haploinsufficiency. We establish that HELQ interacts directly with the RAD51 paralog complex, BCDX2, and functions in parallel to the FA pathway to promote efficient HR at damaged replication forks. Thus, our results reveal a critical role for HELQ in replication-coupled DNA repair, germ cell maintenance and tumour suppression in mammals. PMID:24005329

  10. Quantitative Dynamics of Chromatin Remodeling during Germ Cell Specification from Mouse Embryonic Stem Cells.

    PubMed

    Kurimoto, Kazuki; Yabuta, Yukihiro; Hayashi, Katsuhiko; Ohta, Hiroshi; Kiyonari, Hiroshi; Mitani, Tadahiro; Moritoki, Yoshinobu; Kohri, Kenjiro; Kimura, Hiroshi; Yamamoto, Takuya; Katou, Yuki; Shirahige, Katsuhiko; Saitou, Mitinori

    2015-05-01

    Germ cell specification is accompanied by epigenetic remodeling, the scale and specificity of which are unclear. Here, we quantitatively delineate chromatin dynamics during induction of mouse embryonic stem cells (ESCs) to epiblast-like cells (EpiLCs) and from there into primordial germ cell-like cells (PGCLCs), revealing large-scale reorganization of chromatin signatures including H3K27me3 and H3K9me2 patterns. EpiLCs contain abundant bivalent gene promoters characterized by low H3K27me3, indicating a state primed for differentiation. PGCLCs initially lose H3K4me3 from many bivalent genes but subsequently regain this mark with concomitant upregulation of H3K27me3, particularly at developmental regulatory genes. PGCLCs progressively lose H3K9me2, including at lamina-associated perinuclear heterochromatin, resulting in changes in nuclear architecture. T recruits H3K27ac to activate BLIMP1 and early mesodermal programs during PGCLC specification, which is followed by BLIMP1-mediated repression of a broad range of targets, possibly through recruitment and spreading of H3K27me3. These findings provide a foundation for reconstructing regulatory networks of the germline epigenome. PMID:25800778

  11. Modeling the Epithelial Morphogenesis of Germ Band Retraction in Three Dimensions

    NASA Astrophysics Data System (ADS)

    McCleery, W. Tyler; Veldhuis, Jim; Brodland, G. Wayne; Crews, Sarah M.; Hutson, M. Shane

    2015-03-01

    Embryogenesis of higher-order organisms is driven by an intricate coordination of cellular mechanics. Mechanical analysis of certain developmental events, e.g., dorsal closure in the fruit fly D. melanogaster, has been sufficiently described using two-dimensional models. Here, we present a three-dimensional modeling technique to investigate germ band retraction (GBR) - a whole-embryo, irreducibly 3D morphogenetic event. At the start of GBR, the epithelial tissue known as the germ band is initially wrapped around the posterior end of an ellipsoidal fly embryo. This tissue then retracts as an adjacent epithelial tissue, the amnioserosa, simultaneously contracts. We hypothesize that proper GBR requires maintenance of cell-cell connectivity in the amnioserosa, as well as both cell and tissue topology on the embryo's ellipsoidal surface. The exact interfacial tensions are less important. We test the dynamic interactions between these two tissues on a 3D ellipsoidal last. To speed simulation run times and focus on the relevant tissues, epithelial cells are defined as polygons constrained to lie on the surface of the ellipsoidal last. These cells have adjustable parameters such as edge tensions and cell pressures. Tissue movements are simulated by balancing these dynamic cell-level forces with viscous resistance and allowing cells to exchange neighbors. This modeling approach helps elucidate the multicellular stress fields in normal and aberrant development, providing deeper insight into the mechanical interdependence of developing tissues.

  12. Dominant lethal effects of nocodazole in germ cells of male mice.

    PubMed

    Attia, S M; Ahmad, S F; Okash, R M; Bakheet, S A

    2015-03-01

    The ability of the anticancer drug, nocodazole, to induce dominant lethal mutations in male germ cells was investigated by the in vivo dominant lethal test. Mice were treated with single doses of 15, 30 and 60?mg/kg nocodazole. These males were mated at weekly intervals to virgin females for 6 weeks. Nocodazole clearly induced dominant lethal mutations in the early spermatid stage with the highest tested dose. Mice treated with 60?mg/kg nocodazole showed an additional peak of dominant lethal induction in mature spermatozoa during the first week matings after treatment. The percentage sperm count and sperm motility were significantly decreased after treatment of males with 30 and 60?mg/kg nocodazole. Moreover, the middle and highest doses of nocodazole significantly increased the percentage of abnormal sperm. Our study provides evidence that nocodazole is a germ cell mutagen. Marked alteration in the spermiogram analysis after nocodazole treatment possibly confirms that nocodazole has a significant effect on sperm maturation and development during storage and transit. The demonstrated mutagenicity profile of nocodazole may support further development of effective chemotherapy with less mutagenicity. Moreover, the cancer patients and medical personnel exposed to this drug chemotherapy may stand a higher risk for abnormal reproductive outcomes. PMID:25595372

  13. Reduced insulin/IGF-1 signaling restores germ cell immortality to Caenorhabditis elegans Piwi mutants.

    PubMed

    Simon, Matt; Sarkies, Peter; Ikegami, Kohta; Doebley, Anna-Lisa; Goldstein, Leonard D; Mitchell, Jacinth; Sakaguchi, Aisa; Miska, Eric A; Ahmed, Shawn

    2014-05-01

    Defects in the Piwi/piRNA pathway lead to transposon desilencing and immediate sterility in many organisms. We found that the C. elegans Piwi mutant prg-1 became sterile after growth for many generations. This phenotype did not occur for RNAi mutants with strong transposon-silencing defects and was separable from the role of PRG-1 in transgene silencing. Brief periods of starvation extended the transgenerational lifespan of prg-1 mutants by stimulating the DAF-16/FOXO longevity transcription factor. Constitutive activation of DAF-16 via reduced daf-2 insulin/IGF-1 signaling immortalized prg-1 strains via RNAi proteins and histone H3 lysine 4 demethylases. In late-generation prg-1 mutants, desilencing of repetitive segments of the genome occurred, and silencing of repetitive loci was restored in prg-1; daf-2 mutants. This study reveals an unexpected interface between aging and transgenerational maintenance of germ cells, where somatic longevity is coupled to a genome-silencing pathway that promotes germ cell immortality in parallel to the Piwi/piRNA system. PMID:24767993

  14. Mouse Tafazzin Is Required for Male Germ Cell Meiosis and Spermatogenesis

    PubMed Central

    Cadalbert, Laurence C.; Ghaffar, Farah Naz; Stevenson, David; Bryson, Sheila; Vaz, Frédéric M.; Gottlieb, Eyal; Strathdee, Douglas

    2015-01-01

    Barth syndrome is an X-linked mitochondrial disease, symptoms of which include neutropenia and cardiac myopathy. These symptoms are the most significant clinical consequences of a disease, which is increasingly recognised to have a variable presentation. Mutation in the Taz gene in Xq28 is thought to be responsible for the condition, by altering mitochondrial lipid content and mitochondrial function. Male chimeras carrying a targeted mutation of Taz on their X-chromosome were infertile. Testes from the Taz knockout chimeras were smaller than their control counterparts and this was associated with a disruption of the progression of spermatocytes through meiosis to spermiogenesis. Taz knockout ES cells also showed a defect when differentiated to germ cells in vitro. Mutant spermatocytes failed to progress past the pachytene stage of meiosis and had higher levels of DNA double strand damage and increased levels of endogenous retrotransposon activity. Altogether these data revealed a novel role for Taz in helping to maintain genome integrity in meiosis and facilitating germ cell differentiation. We have unravelled a novel function for the Taz protein, which should contribute to an understanding of how a disruption of the Taz gene results in the complex symptoms underlying Barth Syndrome. PMID:26114544

  15. Meta-analysis identifies four new loci associated with testicular germ cell tumor.

    PubMed

    Chung, Charles C; Kanetsky, Peter A; Wang, Zhaoming; Hildebrandt, Michelle A T; Koster, Roelof; Skotheim, Rolf I; Kratz, Christian P; Turnbull, Clare; Cortessis, Victoria K; Bakken, Anne C; Bishop, D Timothy; Cook, Michael B; Erickson, R Loren; Fosså, Sophie D; Jacobs, Kevin B; Korde, Larissa A; Kraggerud, Sigrid M; Lothe, Ragnhild A; Loud, Jennifer T; Rahman, Nazneen; Skinner, Eila C; Thomas, Duncan C; Wu, Xifeng; Yeager, Meredith; Schumacher, Fredrick R; Greene, Mark H; Schwartz, Stephen M; McGlynn, Katherine A; Chanock, Stephen J; Nathanson, Katherine L

    2013-06-01

    We conducted a meta-analysis to identify new susceptibility loci for testicular germ cell tumor (TGCT). In the discovery phase, we analyzed 931 affected individuals and 1,975 controls from 3 genome-wide association studies (GWAS). We conducted replication in 6 independent sample sets comprising 3,211 affected individuals and 7,591 controls. In the combined analysis, risk of TGCT was significantly associated with markers at four previously unreported loci: 4q22.2 in HPGDS (per-allele odds ratio (OR) = 1.19, 95% confidence interval (CI) = 1.12-1.26; P = 1.11 × 10(-8)), 7p22.3 in MAD1L1 (OR = 1.21, 95% CI = 1.14-1.29; P = 5.59 × 10(-9)), 16q22.3 in RFWD3 (OR = 1.26, 95% CI = 1.18-1.34; P = 5.15 × 10(-12)) and 17q22 (rs9905704: OR = 1.27, 95% CI = 1.18-1.33; P = 4.32 × 10(-13) and rs7221274: OR = 1.20, 95% CI = 1.12-1.28; P = 4.04 × 10(-9)), a locus that includes TEX14, RAD51C and PPM1E. These new TGCT susceptibility loci contain biologically plausible genes encoding proteins important for male germ cell development, chromosomal segregation and the DNA damage response. PMID:23666239

  16. Meta-analysis identifies four new loci associated with testicular germ cell tumor

    PubMed Central

    Chung, Charles C.; Kanetsky, Peter A.; Wang, Zhaoming; Hildebrandt, Michelle A. T.; Koster, Roelof; Skotheim, Rolf I.; Kratz, Christian P.; Turnbull, Clare; Cortessis, Victoria K.; Bakken, Anne C.; Bishop, D. Timothy; Cook, Michael B.; Erickson, R. Loren; Fosså, Sophie D.; Jacobs, Kevin B.; Korde, Larissa A.; Kraggerud, Sigrid M.; Lothe, Ragnhild A.; Loud, Jennifer T.; Rahman, Nazneen; Skinner, Eila C.; Thomas, Duncan C.; Wu, Xifeng; Yeager, Meredith; Schumacher, Fredrick R.; Greene, Mark H.; Schwartz, Stephen M.; McGlynn, Katherine A.; Chanock, Stephen J.; Nathanson, Katherine L.

    2013-01-01

    We conducted a meta-analysis to identify new loci for testicular germ cell tumor (TGCT) susceptibility. In the discovery phase, 931 affected individuals and 1,975 controls from three genome wide association studies (GWAS) were analyzed. Replication was conducted in six independent sample sets totaling 3,211 affected individuals and 7,591 controls. In the combined analysis, TGCT risk was significantly associated with markers at four novel loci: 4q22.2 in HPGDS (per allele odds ratio (OR) 1.19, 95%CI 1.12–1.26, P = 1.11×10?8); 7p22.3 in MAD1L1 (OR 1.21, 95%CI 1.14–1.29, P = 5.59×10?9); 16q22.3 in RFWD3 (OR 1.26, 95%CI 1.18–1.34, P = 5.15×10?12); and 17q22 (rs9905704; OR 1.27, 95%CI 1.18–1.33; P = 4.32×10?13, and rs7221274; OR 1.20, 95%CI 1.12–1.28 P = 4.04×10?9), a locus which includes TEX14, RAD51C and PPM1E. The new TGCT susceptibility loci contain biologically plausible genes encoding proteins important for male germ cell development, chromosomal segregation and DNA damage response. PMID:23666239

  17. Reversal of informational entropy and the acquisition of germ-like immortality by somatic cells.

    PubMed

    Kyriazis, Marios

    2014-01-01

    We live within an increasingly technological, information-laden environment for the first time in human evolution. This subjects us (and will continue to subject us in an accelerating fashion) to an unremitting exposure to 'meaningful information that requires action'. Directly dependent upon this new environment are novel evolutionary pressures, which can modify existing resource allocation mechanisms and may eventually favour the survival of somatic cells (particularly neurons) at the expense of germ line cells. In this theoretical paper I argue that persistent, structured information-sharing in both virtual and real domains, leads to increased biological complexity and functionality, which reflects upon human survival characteristics. Certain biological immortalisation mechanisms currently employed by germ cells may thus need to be downgraded in order to enable somatic cells to manage these new energy demands placed by our modern environment. Relevant concepts from a variety of disciplines such as the evolution of complex adaptive systems, information theory, digital hyper-connectivity, and cell immortalisation will be reviewed. Using logical, though sometimes speculative arguments, I will attempt to describe a new biology. A biology not driven by sex and reproduction but by information and somatic longevity. PMID:24852017

  18. Isolation of human beta-interferon receptor by wheat germ lectin affinity and immunosorbent column chromatographies

    SciTech Connect

    Zhang, Z.Q.; Fournier, A.; Tan, Y.H.

    1986-06-15

    Radioiodinated human beta-interferon-Ser 17 (Betaseron) was reversibly cross-linked to Daudi cells by dithiobis(succinimidylpropionate). The radioactive ligand was cross-linked to three macromolecules forming labeled complexes of apparent Mr values of 130,000, 220,000, and 320,000. Betaseron, human alpha-interferon, human interleukin 2 but not recombinant human gamma-interferon competed with the labeled ligand for binding to these putative receptor(s). Human leukocyte-produced gamma-interferon competed weakly with /sup 125/I-Betaseron for binding to Daudi cells. The Betaseron-receptor complex(es) was purified by passage through a wheat germ lectin column followed by chromatography on an anti-interferon immunosorbent column and semipreparative gel electrophoresis. The cross-linked ligand-receptor complex was shown to be highly purified by sodium dodecyl sulfate and acetic acid:urea:Triton X-100 polyacrylamide gel electrophoresis. It can be dissociated into the labeled Betaseron (Mr = 17,000) ligand and a receptor moiety which has an apparent molecular weight of 110,000. The chromatographic behavior of the ligand-receptor complex on wheat germ lectin column suggests that the receptor is a glycoprotein. The described procedure yielded about 1 microgram of Betaseron receptor from 10(10) Daudi cells, estimated to contain a maximum of about 15 micrograms of the receptor.

  19. Prediction of relapse after lymph node dissection for germ cell tumours: can salvage chemotherapy be avoided?

    PubMed Central

    Berney, D M; Shamash, J; Hendry, W F; Arora, A; Jordan, S; Oliver, R T

    2001-01-01

    Salvage chemotherapy has been used by some oncology centres for patients with residual malignant or immature elements in retroperitoneal lymph node dissections removed for metastatic non-seminomatous germ cell tumours. However, surveillance of these patients shows that many are cured by surgery alone. 118 retroperitoneal lymph node dissections for metastatic non-seminomatous germ cell tumours were reviewed and the morphology seen within them was quantified. 28 of these had immature or malignant elements and had been treated by surveillance before administration of further chemotherapy. The proliferation rate in these cases was assessed by immunochemistry. The proliferation index and the amount of embryonal carcinoma (EC) were both predictors of recurrence and therefore the need for further chemotherapy. Patients with greater than 25% of EC had an 84% chance of relapse and those with a Ki-67 index of greater than 50% had a 71% chance of relapse. The two tests had a positive predictive value of 83% and 71%, respectively. Patients with such a high risk of recurrence could be considered for post-operative adjuvant therapy at this point whilst others would be suitable for a watchful waiting approach. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11161398

  20. Prp22 and Spliceosome Components Regulate Chromatin Dynamics in Germ-Line Polyploid Cells

    PubMed Central

    Klusza, Stephen; Novak, Amanda; Figueroa, Shirelle; Palmer, William; Deng, Wu-Min

    2013-01-01

    During Drosophila oogenesis, the endopolyploid nuclei of germ-line nurse cells undergo a dramatic shift in morphology as oogenesis progresses; the easily-visible chromosomes are initially polytenic during the early stages of oogenesis before they transiently condense into a distinct ‘5-blob’ configuration, with subsequent dispersal into a diffuse state. Mutations in many genes, with diverse cellular functions, can affect the ability of nurse cells to fully decondense their chromatin, resulting in a ‘5-blob arrest’ phenotype that is maintained throughout the later stages of oogenesis. However, the mechanisms and significance of nurse-cell (NC) chromatin dispersal remain poorly understood. Here, we report that a screen for modifiers of the 5-blob phenotype in the germ line isolated the spliceosomal gene peanuts, the Drosophila Prp22. We demonstrate that reduction of spliceosomal activity through loss of peanuts promotes decondensation defects in NC nuclei during mid-oogenesis. We also show that the Prp38 spliceosomal protein accumulates in the nucleoplasm of nurse cells with impaired peanuts function, suggesting that spliceosomal recycling is impaired. Finally, we reveal that loss of additional spliceosomal proteins impairs the full decondensation of NC chromatin during later stages of oogenesis, suggesting that individual spliceosomal subcomplexes modulate expression of the distinct subset of genes that are required for correct morphology in endopolyploid nurse cells. PMID:24244416

  1. Pluripotent stem cells derived from mouse primordial germ cells by small molecule compounds.

    PubMed

    Kimura, Tohru; Kaga, Yoshiaki; Sekita, Yoichi; Fujikawa, Keita; Nakatani, Tsunetoshi; Odamoto, Mika; Funaki, Soichiro; Ikawa, Masahito; Abe, Kuniya; Nakano, Toru

    2015-01-01

    Primordial germ cells (PGCs) can give rise to pluripotent stem cells known as embryonic germ cells (EGCs) when cultured with basic fibroblast growth factor (bFGF), stem cell factor (SCF), and leukemia inhibitory factor. Somatic cells can give rise to induced pluripotent stem cells (iPSCs) by introduction of the reprogramming transcription factors Oct4, Sox2, and Klf4. The effects of Sox2 and Klf4 on somatic cell reprogramming can be reproduced using the small molecule compounds, transforming growth factor-? receptor (TGF?R) inhibitor and Kempaullone, respectively. Here we examined the effects of TGF?R inhibitor and Kempaullone on EGC derivation from PGCs. Treatment of PGCs with TGF?R inhibitor and/or Kempaullone generated pluripotent stem cells under standard embryonic stem cell (ESC) culture conditions without bFGF and SCF, which we termed induced EGCs (iEGCs). The derivation efficiency of iEGCs was dependent on the differentiation stage and sex. DNA methylation levels of imprinted genes in iEGCs were reduced, with the exception of the H19 gene. The promoters of genes involved in germline development were generally hypomethylated in PGCs, but three germline genes showed comparable DNA methylation levels among iEGs, ESCs, and iPSCs. These results show that PGCs can be reprogrammed into pluripotent state using small molecule compounds, and that DNA methylation of these germline genes is not maintained in iEGCs. PMID:25186651

  2. The spectrum of RB1 germ-line mutations in hereditary retinoblastoma

    SciTech Connect

    Lohmann, D.R.; Brandt, B.; Passarge, E. [Universitaetsklinikum Essen (Germany)] [and others

    1996-05-01

    We have searched for germ-line RB1 mutations in 119 patients with hereditary retinoblastoma. Previous investigations by Southern blot hybridization and PCR fragment-length analysis had revealed mutations in 48 patients. Here we report on the analysis of the remaining 71 patients. By applying heteroduplex analysis, nonisotopic SSCP, and direct sequencing, we detected germ-line mutations resulting in premature termination codons or disruption of splice signals in 51 (72%) of the 71 patients. Four patients also showed rare sequence variants. No region of the RB1 gene was preferentially involved in single base substitutions. Recurrent transitions were observed at most of the 14 CGA codons within the RB1. No mutation was observed in exons 25-27, although this region contains two CGA codons. This suggests that mutations within the 3{prime}-terminal region of the RB1 gene may not be oncogenic. When these data were combined with the results of our previous investigations, mutations were identified in a total of 99 (83%) of 119 patients. The spectrum comprises 15% large deletions, 26% small length alterations, and 42% base substitutions. No correlation between the location of frameshift or nonsense mutations and phenotypic features, including age at diagnosis, the number of tumor foci, and manifestation of monocular tumors was observed. 42 refs., 3 figs., 1 tab.

  3. A mesodermal factor, T, specifies mouse germ cell fate by directly activating germline determinants.

    PubMed

    Aramaki, Shinya; Hayashi, Katsuhiko; Kurimoto, Kazuki; Ohta, Hiroshi; Yabuta, Yukihiro; Iwanari, Hiroko; Mochizuki, Yasuhiro; Hamakubo, Takao; Kato, Yuki; Shirahige, Katsuhiko; Saitou, Mitinori

    2013-12-01

    Germ cells ensure reproduction and heredity. In mice, primordial germ cells (PGCs), the precursors for spermatozoa and oocytes, are induced in pluripotent epiblast by BMP4 and WNT3, yet the underlying mechanism remains unclear. Here, using an in vitro PGC specification system, we show that WNT3 induces many transcription factors associated with mesoderm in epiblast-like cells through ?-CATENIN. Among these, T (BRACHYURY), a classical and conserved mesodermal factor, was essential for robust activation of Blimp1 and Prdm14, two of the germline determinants. T, but not SMAD1 or TCF1, binds distinct regulatory elements of both Blimp1 and Prdm14 and directly upregulates these genes, delineating the downstream PGC program. Without BMP4, a program induced by WNT3 prevents T from activating Blimp1 and Prdm14, demonstrating a permissive role of BMP4 in PGC specification. These findings establish the key signaling mechanism for, and a fundamental role of a mesodermal factor in, mammalian PGC specification. PMID:24331926

  4. The germ cell determinant Blimp1 is not required for derivation of pluripotent stem cells.

    PubMed

    Bao, Siqin; Leitch, Harry G; Gillich, Astrid; Nichols, Jennifer; Tang, Fuchou; Kim, Shinseog; Lee, Caroline; Zwaka, Thomas; Li, Xihe; Surani, M Azim

    2012-07-01

    Blimp1 (Prdm1), the key determinant of primordial germ cells (PGCs), plays a combinatorial role with Prdm14 during PGC specification from postimplantation epiblast cells. They together initiate epigenetic reprogramming in early germ cells toward an underlying pluripotent state, which is equivalent to embryonic stem cells (ESCs). Whereas Prdm14 alone can promote reprogramming and is important for the propagation of the pluripotent state, it is not known whether Blimp1 is similarly involved. By using a genetic approach, we demonstrate that Blimp1 is dispensable for the derivation and maintenance of ESCs and postimplantation epiblast stem cells (epiSCs). Notably, Blimp1 is also dispensable for reprogramming epiSCs to ESCs. Thus, although Blimp1 is obligatory for PGC specification, it is not required for the reversion of epiSCs to ESCs and for their maintenance thereafter. This study suggests that reprogramming, including that of somatic cells to ESCs, may not entail an obligatory route through a Blimp1-positive PGC-like state. PMID:22770244

  5. The effect of fluoride on mineralization during tooth germ development in neonatal hamsters

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Lyaruu, D. M.; Vis, R. D.

    1990-04-01

    The effect of fluoride on calcium and phosphorus content (a measure for mineralization) in maxillary first molar tooth germs from neonatal hamsters (4 to 5 days old, 4 to 5 g body weight) was analysed using the proton nuclear microprobe PIXE setup of the Vrije Universiteit. A 3 MeV proton beam of about 500 pA with a spot size of 5 × 20 ?m 2 was used to perform scans of about 400 ?m, each taking about 20 to 30 minutes. The smaller beam dimension was always tuned parallel to the scan direction. Line scans with a lateral resolution of 5 ?m were made across the enamel organ of germs from animals injected with 20 mg NaF/kg body weight 24 h prior to dissection. The control animals were injected with NaCl. Fluoride administration induced the formation of sub-ameloblastic cystic lesions under some (but not all) populations of transitional and secretory ameloblasts, accompanied by hypermineralization (deposition of more mineral than that found in the controls) of the underlying enamel surface. These hypermineralized regions had been shown in earlier studies to contain elevated fluorine content [1,2].

  6. Germ Wars

    ERIC Educational Resources Information Center

    Alderson, Kris

    2009-01-01

    It's estimated that at least 22 million school days are lost every year because of colds caught by students and faculty, according to the Centers for Disease Control and Prevention (CDC). There's still no cure for the common cold, but there is a time-honored way to prevent it: handwashing, ideally with good old soap and water. It's still the best…

  7. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (editor); Moorehead, Tauna W. (editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  8. An open, prospective, randomized pilot investigation evaluating pain with the use of a soft silicone wound contact layer vs bridal veil and staples on split thickness skin grafts as a primary dressing.

    PubMed

    Patton, Mary Lou; Mullins, Robert Fred; Smith, David; Korentager, Richard

    2013-01-01

    An open, prospective, randomized, pilot investigation was implemented to evaluate the pain, cost-effectiveness, ease of use, tolerance, efficacy, and safety of a soft silicone wound contact layer (Mepitel One) vs Bridal Veil and staples used on split thickness skin grafts in the treatment of deep partial or full-thickness thermal burns. Individuals aged between 18 and 70 years with deep partial or full-thickness thermal burns (1-25% TBSA) were randomized into two groups and treated for 14 days or until greater than 95% graft take was achieved, whichever occurred first. Data were obtained and analyzed on pain experienced before, during, and after dressing removal. Secondary considerations included the overall cost (direct), graft take and healing, the ease of product use, overall experience of the dressing, and adverse events. A total of 43 subjects were recruited. There were no significant differences in burn area profiles within the groups. The pain level during dressing removal was significant between the groups (P = .0118) with the removal of Mepitel One being less painful. The staff costs were lower in the group of patients treated with Mepitel One (P = .0064) as reflected in the shorter time required for dressing removal (P = .0005), with Mepitel One taking on average less than a quarter of the time to remove. There was no significant difference in healing between the two groups, with 99.0% of the Mepitel One group and 93.1% of the Bridal Veil and staples group showing greater than 95% graft take at post-op day 7 (+/-1) (P = .2373). Clinicians reported that the soft silicone dressing was easier to use, more conformable, and demonstrated better ability to stay in place, compared with the Bridal Veil and staples regime. Both treatments were well tolerated, with no serious adverse events in either treatment group. Mepitel One was at least as effective in the treatment of patients as the standard care (Bridal Veil and staples). In addition, the group of patients treated with the soft silicone dressing demonstrated decreased pain and lower costs associated with treatment. PMID:23817002

  9. IP Layer Input Packet Processing The receive functions of the IP layer include

    E-print Network

    Westall, James M.

    IP Layer Input Packet Processing The receive functions of the IP layer include: · IP header validation; · IP header option processing; · Reassembly of fragmented packets; · Routing of the input packet_buff. This the primary concern of the ip_rcv() function which is defined in net/ipv4/ip_input.c. 370 /* 371 * Main IP

  10. Wheat germ agglutinin anchored chitosan microspheres of reduced brominated derivative of noscapine ameliorated acute inflammation in experimental colitis.

    PubMed

    Kaur, Kamalpreet; Sodhi, Rupinder Kaur; Katyal, Anju; Aneja, Ritu; Jain, Upendra Kumar; Katare, Om Prakash; Madan, Jitender

    2015-08-01

    Reduced brominated derivative of noscapine (Red-Br-Nos, EM012), has potent anti-inflammatory property. However, physicochemical limitations of Red-Br-Nos like low aqueous solubility (0.43×10(-3)g/mL), high lipophilicity (logP?2.94) and ionization at acidic pH greatly encumber the scale-up of oral drug delivery systems for the management of colitis. Therefore, in present investigation, chitosan microspheres bearing Red-Br-Nos (CTS-MS-Red-Br-Nos) were prepared by emulsion polymerization method and later coated with wheat germ agglutinin (WGA-CTS-MS-Red-Br-Nos) to boost the bioadhesive property. The mean particle size and zeta-potential of CTS-MS-Red-Br-Nos were measured to be 10.5±5.4?m and 8.1±2.2mV, significantly (P<0.05) lesser than, 30.2±3.2?m and 19.2±2.3mV of WGA-CTS-MS-Red-Br-Nos. Furthermore, various spectral techniques like SEM, FT-IR, DSC and PXRD substantiated that Red-Br-Nos was molecularly dispersed in tailored microspheres in amorphous state. Surface bioadhesive property of WGA-CTS-MS-Red-Br-Nos promoted the affinity toward colon mucin cells in simulated colonic fluid (SCF, pH?7.2). In vitro release studies carried out on WGA-CTS-MS-Red-Br-Nos and CTS-MS-Red-Br-Nos indicated that SCF with colitis milieu (pH?4.7) favored the controlled release of Red-Br-Nos, owing to solubilization at acidic pH. Consistently, in vivo investigation also demonstrated the utility of WGA-CTS-MS-Red-Br-Nos, which remarkably attenuated the DSS encouraged neutrophil infiltration, myeloperoxidase activity, and pro-inflammatory cytokine production in C57BL6J mice, as compared to CTS-MS-Red-Br-Nos and Red-Br-Nos suspension. The noteworthy anti-inflammatory activity of WGA-CTS-MS-Red-Br-Nos against acute colitis may be attributed to enhanced drug delivery, affinity and utmost drug exposure at inflamed mucosal layers of colon. In conclusion, WGA-CTS-MS-Red-Br-Nos warrants further in-depth in vitro and in vivo investigations to scale-up the technology for clinical translation. PMID:26047885

  11. Acquiring Peak Samples from Phytoplankton Thin Layers and Intermediate Nepheloid Layers by an Autonomous Underwater Vehicle with Adaptive Triggering

    Microsoft Academic Search

    Y. Zhang; R. McEwen; J. P. Ryan; J. G. Bellingham; J. Harvey; R. Vrijenhoek

    2010-01-01

    Phytoplankton thin layers (PTLs) affect many fundamental aspects of coastal ocean ecology including primary productivity, development of harmful algal blooms (HABs) and the survival and growth of zooplankton and fish larvae. Intermediate nepheloid layers (INLs) that contain suspended particulate matter transported from the bottom boundary layer of continental shelves and slopes also affect biogeochemistry and ecology of ocean margins. To

  12. Polar Layers

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03083 Polar Layers

    This VIS image illlustrates how distinct polar layers appear with no frost cover. This image was collected during the height of summer at the south pole of Mars.

    Image information: VIS instrument. Latitude 80.7S, Longitude 295.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Polar Layers

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03288 Polar Layers

    Late in the summer season, the numerous polar layers are free of frost and easily visible.

    Image information: VIS instrument. Latitude -84.9N, Longitude 135.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Exploring embryonic germ line development in the water flea, Daphnia magna, by zinc-finger-containing VASA as a marker.

    PubMed

    Sagawa, Kazunori; Yamagata, Hideo; Shiga, Yasuhiro

    2005-06-01

    VASA is an ATP-dependent RNA helicase belonging to the DEAD-box family that, in many organisms, is specifically expressed in germ line cells throughout the life cycle, making it a powerful molecular marker to study germ line development. To obtain further information on germ line development in crustaceans, we cloned VASA cDNAs from three branchiopod species: water fleas Daphnia magna and Moina macrocopa, and brine shrimp Artemia franciscana. RNA helicase domains in branchiopod VASA were highly conserved among arthropod classes. However, N-terminal RNA-binding domains in branchiopod VASA were highly diverged and, unlike other arthropod VASA reported so far, possessed repeats of retroviral-type zinc finger (CCHC) motifs. Raising specific antibodies against Daphnia VASA revealed that the primordial germ cells (PGCs) in this organism segregate at a very early cleavage stage of embryogenesis in parthenogenetic and sexual eggs. Clusters of PGCs then start to migrate inside the embryo and finally settle at both sides of the intestine, the site of future gonad development. RNA analyses suggested that maternally supplied vasa mRNA was responsible for early VASA expression, while zygotic expression started during blastodermal stage of development. PMID:15939379

  15. ATTACHMENT AND ADHESION OF CONIDIA AND GERM TUBES OF1 Stagonospora nodorum TO NATURAL AND ARTIFICIAL SURFACES2

    E-print Network

    ATTACHMENT AND ADHESION OF CONIDIA AND GERM TUBES OF1 Stagonospora nodorum TO NATURAL ________________________________________________________________________10 Abstract11 Attachment and adhesion of conidia of a wheat-isolate of the foliar pathogen12. Irreversible attachment took place almost15 immediately. No difference was found between numbers of washed

  16. A multi-disciplinary Delphi method to identify consensus in the management of intracranial germ cell tumours

    E-print Network

    Murray, Matthew J.; Bartels, Ute; Nishikawa, Ryo; Fangusaro, Jason; Matsutani, Masao; Nicholson, James C.

    2015-01-01

    , Chuba P, et al. A phase II trial of neoadjuvant chemotherapy +/- second-look surgery prior to radiotherapy for non- germinomatous germ cell tumors (NGGCT): Children's Oncology Group ACNS0122. Neuro Oncol. 2010; 12(6): ii29. 6. Fukushima S, Otsuka A...

  17. A Novel Member of the Tob Family of Proteins Controls Sexual Fate in Caenorhabditis elegans Germ Cells

    Microsoft Academic Search

    Pei-Jiun Chen; Amit Singal; Judith Kimble; Ronald E. Ellis

    2000-01-01

    Although many cell fates differ between males and females, probably the most ancient type of sexual dimorphism is the decision of germ cells to develop as sperm or as oocytes. Genetic analyses of Caenorhabditis elegans suggest that fog-3 might directly control this decision. We used transformation rescue to clone the fog-3 gene and show that it produces a single major

  18. Amygdalin (Laetrile) and Prunasin beta -glucosidases: Distribution in Germ-Free Rat and in Human Tumor Tissue

    Microsoft Academic Search

    Jonathan Newmark; Roscoe O. Brady; Philip M. Grimley; Andrew E. Gal; Stephen G. Waller; J. Richard Thistlethwaite

    1981-01-01

    Amygdalin, the gentiobioside derivative of mandelonitrile commonly referred to as Laetrile, is presently under intensive investigation as a potential cancer chemotherapeutic agent. Because of this interest, we investigated the activity of beta -glucosidases that cleave glucose from amygdalin and from prunasin (mandelonitrile monoglucoside) in tissues from germ-free rats and in normal and neoplastic human tissues. Rat and human small intestinal

  19. SPR-5 and MET-2 function cooperatively to reestablish an epigenetic ground state during passage through the germ line.

    PubMed

    Kerr, Shana C; Ruppersburg, Chelsey Chandler; Francis, Joshua W; Katz, David J

    2014-07-01

    The Caenorhabditis elegans LSD1 H3K4me2 demethylase SPR-5 reprograms epigenetic transcriptional memory during passage through the germ line. Here we show that mutants in the H3K9me2 methyltransferase, met-2, result in transgenerational epigenetic effects that parallel spr-5 mutants. In addition, we find that spr-5;met-2 double mutants have a synergistic effect on sterility, H3K4me2, and spermatogenesis expression. These results implicate MET-2 as a second histone-modifying enzyme in germ-line reprogramming and suggest a model in which SPR-5 and MET-2 function cooperatively to reestablish an epigenetic ground state required for the continued immortality of the C. elegans germ line. Without SPR-5 and MET-2, we find that the ability to express spermatogenesis genes is transgenerationally passed on to the somatic cells of the subsequent generation. This indicates that H3K4me2 may act in the maintenance of cell fate. Finally, we demonstrate that reducing H3K4me2 causes a large increase in H3K9me2 added by the SPR-5;MET-2 reprogramming mechanism. This finding suggests a novel histone code interaction in which the input chromatin environment dictates the output chromatin state. Taken together, our results provide evidence for a broader reprogramming mechanism in which multiple enzymes coordinately regulate histone information during passage through the germ line. PMID:24979765

  20. Caenorhabditis elegans RSD-2 and RSD-6 promote germ cell immortality by maintaining small interfering RNA populations.

    PubMed

    Sakaguchi, Aisa; Sarkies, Peter; Simon, Matt; Doebley, Anna-Lisa; Goldstein, Leonard D; Hedges, Ashley; Ikegami, Kohta; Alvares, Stacy M; Yang, Liwei; LaRocque, Jeannine R; Hall, Julie; Miska, Eric A; Ahmed, Shawn

    2014-10-14

    Germ cells are maintained in a pristine non-aging state as they proliferate over generations. Here, we show that a novel function of the Caenorhabditis elegans RNA interference proteins RNAi spreading defective (RSD)-2 and RSD-6 is to promote germ cell immortality at high temperature. rsd mutants cultured at high temperatures became progressively sterile and displayed loss of small interfering RNAs (siRNAs) that target spermatogenesis genes, simple repeats, and transposons. Desilencing of spermatogenesis genes occurred in late-generation rsd mutants, although defective spermatogenesis was insufficient to explain the majority of sterility. Increased expression of repetitive loci occurred in both germ and somatic cells of late-generation rsd mutant adults, suggesting that desilencing of many heterochromatic segments of the genome contributes to sterility. Nuclear RNAi defective (NRDE)-2 promotes nuclear silencing in response to exogenous double-stranded RNA, and our data imply that RSD-2, RSD-6, and NRDE-2 function in a common transgenerational nuclear silencing pathway that responds to endogenous siRNAs. We propose that RSD-2 and RSD-6 promote germ cell immortality at stressful temperatures by maintaining transgenerational epigenetic inheritance of endogenous siRNA populations that promote genome silencing. PMID:25258416