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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. Molecular specification of germ layers in vertebrate embryos.

    PubMed

    Kiecker, Clemens; Bates, Thomas; Bell, Esther

    2016-03-01

    In order to generate the tissues and organs of a multicellular organism, different cell types have to be generated during embryonic development. The first step in this process of cellular diversification is the formation of the three germ layers: ectoderm, endoderm and mesoderm. The ectoderm gives rise to the nervous system, epidermis and various neural crest-derived tissues, the endoderm goes on to form the gastrointestinal, respiratory and urinary systems as well as many endocrine glands, and the mesoderm will form the notochord, axial skeleton, cartilage, connective tissue, trunk muscles, kidneys and blood. Classic experiments in amphibian embryos revealed the tissue interactions involved in germ layer formation and provided the groundwork for the identification of secreted and intracellular factors involved in this process. We will begin this review by summarising the key findings of those studies. We will then evaluate them in the light of more recent genetic studies that helped clarify which of the previously identified factors are required for germ layer formation in vivo, and to what extent the mechanisms identified in amphibians are conserved across other vertebrate species. Collectively, these studies have started to reveal the gene regulatory network (GRN) underlying vertebrate germ layer specification and we will conclude our review by providing examples how our understanding of this GRN can be employed to differentiate stem cells in a targeted fashion for therapeutic purposes. PMID:26667903

  3. SOX17 links gut endoderm morphogenesis with germ layer segregation

    PubMed Central

    Viotti, Manuel; Nowotschin, Sonja; Hadjantonakis, Anna-Katerina

    2014-01-01

    Gastrulation leads to three germ layers, ectoderm, mesoderm and endoderm that are separated by two basement membranes. In the mouse embryo, the emergent gut endoderm results from the widespread intercalation of cells of two distinct origins: pluripotent epiblast-derived definitive endoderm (DE) and extra-embryonic visceral endoderm (VE). Here we image the trajectory of prospective DE cells prior to intercalating into the VE epithelium. We show that the transcription factor SOX17, which is activated in prospective DE cells prior to intercalation, is necessary for gut endoderm morphogenesis and the assembly of the basement membrane that separates gut endoderm from mesoderm. Our results mechanistically link gut endoderm morphogenesis and germ layer segregation, two central and conserved features of gastrulation. PMID:25419850

  4. Surgery in the management of primary intracranial germ cell tumors.

    PubMed

    Weiner, H L; Finlay, J L

    1999-11-01

    Surgery plays an important part in the overall management of primary central nervous system (CNS) germ cell tumors. While the general surgical objectives in patients with these neoplasms are similar to those with other types of CNS tumors, to obtain an accurate histopathologic diagnosis and to contribute towards improving patient survival the unique features of germ cell tumors have necessitated novel treatment strategies. Pure germinomas are exquisitely radiosensitive, and prior studies have shown no survival benefit from radical resection of such lesions. However, a significant proportion of CNS GCTs contain admixtures of nongerminomatous GCT (NGGCT) elements and are less responsive to aggressive chemotherapy and irradiation. Biopsy of these malignant GCTs carries the risk of histologic sampling error. Nevertheless, a proportion of NGGCTs produce tumor markers detectable in serum or CSF and may be accurately diagnosed without surgical intervention. Although the role of radical surgical resection has not been definitively demonstrated in the literature, recent data from an international cooperative trial suggest a survival benefit from radical resection of localized NGGCTs. Lastly, increasing experience has supported the role of delayed resective ("second-look") surgery for patients with negative tumor markers but residual radiographic abnormalities after initial chemotherapy. Resection of such lesions has typically yielded necrosis or teratoma, which may be cured by surgical resection, and obviated the need for additional chemotherapy or irradiation. PMID:10603021

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

    PubMed Central

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

    2014-01-01

    The germ layer concept has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years1-3. 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 evolve1,4,5. The origin of the ectoderm and endoderm germ layers, however, remains unclear with models supporting the antecedence of each as well as a simultaneous origin4,6-9. 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 to both evolve and develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier, and this is observed also in the expression of endoderm orthologs during the embryology of Xenopus tropicalis, Nematostella vectensis, and the sponge Amphimedon queenslandica. Querying for the phylogenetic ages of specifically expressed genes revealed that the endoderm is comprised of older genes. Taken together, we propose that the endoderm program dates back to the origin of multicellularity, while the ectoderm originated as a secondary germ layer freed from ancestral feeding functions. PMID:25487147

  6. 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

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

    PubMed Central

    Paul, Arun; Parmar, Harshad; Chacko, Rabin

    2015-01-01

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

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

    PubMed Central

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

    2011-01-01

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

  9. Germ cell-specific Atg7 knockout results in primary ovarian insufficiency in female mice

    PubMed Central

    Song, Z-H; Yu, H-Y; Wang, P; Mao, G-K; Liu, W-X; Li, M-N; Wang, H-N; Shang, Y-L; Liu, C; Xu, Z-L; Sun, Q-Y; Li, W

    2015-01-01

    Primary ovarian insufficiency (POI) is a common cause of infertility in around 1–2% of women aged <40 years. However, the mechanisms that cause POI are still poorly understood. Here we showed that germ cell-specific knockout of an essential autophagy induction gene Atg7 led to subfertility in female mice. The subfertility of Atg7 deletion females was caused by severe ovarian follicle loss, which is very similar to human POI patients. Further investigation revealed that germ cell-specific Atg7 knockout resulted in germ cell over-loss at the neonatal transition period. In addition, our in vitro studies also demonstrated that autophagy could protect oocytes from over-loss by apoptosis in neonatal ovaries under the starvation condition. Taken together, our results uncover a new role for autophagy in the regulation of ovarian primordial follicle reservation and hint that autophagy-related genes might be potential pathogenic genes to POI of women. PMID:25590799

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

    PubMed

    Cao, Ying

    2015-04-01

    The African clawed frog, Xenopus laevis, has long been a model animal for the studies in the fields of animal cloning, developmental biology, biochemistry, cell biology, and physiology. With the aid of Xenopus, major molecular mechanisms that are involved in embryonic development have been understood. Germ layer formation is the first event of embryonic cellular differentiation, which is induced by a few key maternal factors and subsequently by zygotic signals. Meanwhile, another type of signals, the pluripotency factors in ES cells, which maintain the undifferentiated state, are also present during early embryonic cells. In this review, the functions of the pluripotency factors during Xenopus germ layer formation and the regulatory relationship between the signals that promote differentiation and pluripotency factors are discussed. PMID:25862657

  11. Primary intracranial germ cell tumours: experience of a single South-East Asian institution.

    PubMed

    Foo, Aaron S C; Lim, Cindy; Chong, Dawn Q Q; Tan, Daniel Y H; Tham, Chee Kian

    2014-10-01

    Primary intracranial germ cell tumours (ICGCT) are a rare group of brain tumours arising predominantly in the paediatric and pre-adult population, accounting for up to 9.5% of paediatric brain tumours in East Asia. The National Cancer Centre Singapore (NCCS) is a tertiary referral centre for patients from all over South-East Asia. Our study aims to describe the characteristics of ICGCT patients in South-East Asia. Data on all patients with ICGCT who were seen at the Therapeutic Radiology Department of NCCS from 2000 to 2013 were collected retrospectively. Patient demographics, disease characteristics and treatment outcomes were analysed. Characteristics and survival of our patients were similar to other centres. Pure germinomas demonstrated 5 year overall survival (OS) and disease-free survival (DFS) rates of 89.2% (95% confidence interval [CI] 60.2-97.5) and 85.2% (95%CI 60.8-95.0) respectively. Secreting germinomas, non-germinomatous germ cell tumours and mixed germ cell tumours were evaluated together and demonstrated 5 year OS of 70.6% (95%CI 41.0-87.3) and DFS of 61.4% (95%CI 31.9-81.3). Patients ? 12 years had marginally better 5 year OS than their older counterparts (81.0% [95%CI 49.5-93.9] versus 77.9% [95%CI 47.3-92.0], respectively). Patients who underwent extended field radiotherapy had longer OS and DFS than those who received local field irradiation. Treatment outcomes of our ICGCT patients are comparable with those in other Asian and Western centres. Extended field radiotherapy is a pivotal component of ICGCT treatment. Adding chemotherapy confers no extra survival benefit in treating germinomas. Treatment of mixed germ cell tumours and non-germinomatous germ cell tumours involves a multidisciplinary approach that varies for each histological subtype. PMID:24954243

  12. 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

  13. 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

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

    PubMed

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

    2004-04-28

    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

  15. Treatment of a primary intracranial germ cell tumor with systemic chemotherapy

    SciTech Connect

    Kirshner, J.J.; Ginsberg, S.J.; Fitzpatrick, A.V.; Comis, R.L.

    1981-01-01

    Primary germ cell neoplasms of the central nervous system (CNS) are rare tumors which generally respond to radiotherapy. Experience is limited in managing the refractory patient. We report a patient whose suprasellar dysgerminoma responded completely to 5,000 rad. Seven years later, disease recurrence was refractory to an additional 4,000 rad. Theorizing that the ''blood-brain barrier'' was no longer intact after extensive radiotherapy and tumor involvement of the ventricular system, the patient was treated with systemic bleomycin, cisplatin, and vinblastine. Pharmacokinetic studies revealed that the bleomycin and cisplatin entered the cerebrospinal fluid. Serial CT scans and CSF levels of beta-HCG confirmed the clinical impression of a partial remission. Subsequent tumor progression was refractory to therapy with intraventricular bleomycin. It is concluded that systemic chemotherapy may be beneficial in certain cases of CNS germ cell neoplasms.

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

    PubMed Central

    Gao, Yuping; Jiang, Jiyao; Liu, Qiang

    2014-01-01

    Primary central nervous system (CNS) germ cell tumors (GCTs) are a rare heterogeneous group of lesions, which the clinicopathological features have a marked degree of heterogeneity comparing with that of gonadal GCTs. Accurately diagnosing CNS GCTs might be extremely difficult and requires immunohistochemical verification. This study was to investigate the biological feature of CNS GCTs and diagnostic value of immunohistochemical markers OCT3/4, C-kit, PLAP, and CD30 in CNS GCTs. A retrospective study was performed on 34 patients with CNS germ cell tumors between 1990 and 2014. 34 CNS GCTs account for 9.2% of all primary CNS neoplasms. The sellar region (35.3%) and pineal gland (17.6%) were the most common sites of intracranial GCTs. Hydrocephalus (82.4%) and diplopia (46.9%) were the two most common clinical presentations. The most common histological subtypes were germinoma (67.6%). PLAP, c-kit, OCT3/4 were highly expressed in gernimomas. CD30 and CK AE1/3 stainings were positive in embryonal carcinoma. Yolk sac tumor component showed positive staining for AFP and CK AE1/3. ?-HCG staining was positive in choriocarcinoma and STGC. Patients with mature teratomas and germinomas had a better prognosis (a 5-year survival rate) than those with embryonal carcinoma and choriocarcinoma (a 5-year survival rates were 0). Our finding suggest that the incidences of primary CNS GCTs are higher in South China than in the West, but mixed GCTs are uncommon in our study. The judicious use of a panel of selected markers is helpful in diagnosing and predicting the prognosis for CNS GCTs. PMID:25400782

  17. Primary extragonadal germ cell tumor: A case report on prostate seminoma

    PubMed Central

    ZHENG, WEI; WANG, LINA; YANG, DEYONG; FANG, KUN; CHEN, XIAOCHI; WANG, XUEJIAN; LI, XIANCHENG; LI, ZIYAO; SONG, XISHUANG; WANG, JIANBO

    2015-01-01

    Primary extragonadal germ cell tumors are rare, and 60% of such cases are seminomas. While the tumors can occur in the mediastinum, thymus, retroperitoneal organs and pineal gland, seminoma originating in the prostate tissue is extremely rare. The present study reports the case of a 54-year-old male with prostate seminoma. The patient was followed up at the First Affiliated Hospital of Dalian Medical University (Dalian, Liaoning, China) from 2001 onwards. The patient received chemotherapy with cyclophosphamide following total resection of the pelvic organs, pelvic lymph node dissection, continent detenial cecum-ascending colic bladder and orchidectomy. The patient experienced considerable post-operative quality of life for >10 years and the disease did not reappear. The study indicated that extragonadal seminoma is sensitive to chemotherapy, and that radical surgery and post-operative adjuvant chemotherapy with cyclophosphamide is a reasonable and feasible treatment method. PMID:26622843

  18. 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

  19. Metachronous gonadal and extragonadal primaries, or late relapse of germ cell tumor?

    PubMed

    Daniel, C; Fizazi, K; Culine, S; Zelek, L; Wibault, P; Theodore, C

    2001-03-01

    We report five distinct cases of apparently metachronous extragonadal and gonadal germ cell tumors (GCT) occurring in the same patient. Two patients had metachronous GCT of the central nervous system and the testis. One of these patients had been successfully treated for a germinoma of the pineal gland and developed a nonseminomatous GCT of the testis 10 years later. The second patient had a primary seminoma of the testis treated by orchiectomy followed by radiotherapy and developed a germinoma of the sphenoidal sinus 17 months later. Three other patients had an apparently metachronous retroperitoneal and testicular GCT with 22, 44, and 66 months elapsing, respectively, between the first and second neoplasms. These cases suggest that the remaining testis is not only at risk for a second primary GCT, but that a second GCT may emerge at an extragonadal site. A genetic predisposition may account for some of these cases and the occurrence of bilateral testicular GCT. In none of these cases, however, could we ascertain whether testicular GCT was truly a second primary or a relapse of a "primary" retroperitoneal GCT in our cases. PMID:11166620

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

    PubMed

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

    2016-01-01

    Endothelial glycocalyx (GCX) is located on the apical surface of vascular endothelial cells and is composed of a negatively-charged network of proteoglycans and glycoproteins. The GCX plays an important role in maintaining the integrity of vascular walls and preventing leakage of plasma. Therefore, degradation of the GCX is believed to lead to pathological leakage of plasma. Because the GCX is a very thin layer, its ultrastructural image has been demonstrated on electron microscope. To explore the function of the GCX, it should be visualized by a microscope in vivo. Thus, we developed in vivo visualization technique of the GCX under fluorescence microscopy using a mouse dorsal skinfold chamber (DSC) model. To label and visualize the GCX, we used fluorescein isothiocyanate (FITC)-labeled lectin, which has a high specificity for sugar moieties. We examined the affinity of the different lectins to epivascular regions under an intravital fluorescent microscope. Among seven different lectins we examined, FITC labeled Triticum vulgaris (wheat germ) agglutinin (WGA) delineated the GCX most clearly. Binding of WGA to the GCX was inhibited by chitin hydrolysate, which contained WGA-binding polysaccharide chains. Furthermore, the septic condition attenuated this structure, suggesting structural degradation of endothelial GCX layer. In conclusion, FITC-labeled WGA lectin enabled visualization of endothelial GCX under in vivo fluorescence microscopy. Microsc. Res. Tech. 79:31-37, 2016. © 2015 Wiley Periodicals, Inc. PMID:26768789

  1. 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

  2. A Pathogenic Mosaic TP53 Mutation in Two Germ Layers Detected by Next Generation Sequencing

    PubMed Central

    Williams, Richard D.; Side, Lucy; Hubank, Mike; West, Rebecca; Pearson, Katie; Sebire, Neil; Tarpey, Patrick; Futreal, Andrew; Brooks, Tony; Stratton, Michael R.; Anderson, John

    2014-01-01

    Background Li-Fraumeni syndrome is caused by germline TP53 mutations and is clinically characterized by a predisposition to a range of cancers, most commonly sarcoma, brain tumours and leukemia. Pathogenic mosaic TP53 mutations have only rarely been described. Methods and Findings We describe a 2 years old child presenting with three separate cancers over a 6 month period; two soft tissue mesenchymal tumors and an aggressive metastatic neuroblastoma. As conventional testing of blood DNA by Sanger sequencing for mutations in TP53, ALK, and SDH was negative, whole exome sequencing of the blood DNA of the patient and both parents was performed to screen more widely for cancer predisposing mutations. In the patient's but not the parents' DNA we found a c.743 G>A, p.Arg248Gln (CCDS11118.1) TP53 mutation in 3–20% of sequencing reads, a level that would not generally be detectable by Sanger sequencing. Homozygosity for this mutation was detected in all tumor samples analyzed, and germline mosaicism was demonstrated by analysis of the child's newborn blood spot DNA. The occurrence of separate tumors derived from different germ layers suggests that this de novo mutation occurred early in embryogenesis, prior to gastrulation. Conclusion The case demonstrates pathogenic mosaicim, detected by next generation deep sequencing, that arose in the early stages of embryogenesis. PMID:24810334

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

    PubMed

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

    2003-11-27

    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. PMID:14647383

  4. 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.

  5. [PRIMARY MEDIASTINAL GERM CELL TUMOR ARISING IN A PATIENT WITH NEUROFIBROMATOSIS TYPE 1].

    PubMed

    Kashima, Soki; Saito, Mitsuru; Tsuchiya, Norihiko; Saito, Hajime; Nanjo, Hiroshi; Numakura, Kazuyuki; Tsuruta, Hiroshi; Akihama, Susumu; Inoue, Takamitsu; Narita, Shintaro; Minamiya, Yoshihiro; Satoh, Shigeru; Habuchi, Tomonori

    2015-07-01

    Neurofibromatosis type 1 (NF1) is a distinct genetic disorder due to the NF1 gene mutation which induces the aberrant activation of the RAS-signaling. Because RAS-related proteins function as oncogenic factors, NF1 patients frequently develop malignant tumors, especially of neural crest origin, such as peripheral nerve sheath. In addition, malignant tumors of the pancreas, colorectum, and lung have been reported to frequently arise in NF1 patients. However, the association between germ cell tumor and NF1 has not been clarified yet. A 29-year-old male with dyspnea was referred to our hospital because of the large mass in the anterior mediastinum and cervical lymph node swelling. The diagnosis was extragonadal germ cell tumor with cervical lymph node metastasis, and complete remission was obtained by multidisciplinary treatment consisted of combination chemotherapy and surgical resection. To our acknowledgement, this is the first case of extragonadal germ cell tumor in NF1 patients. We discuss the relevance between activation of the RAS-signaling and the development of germ cell tumor. PMID:26419075

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

    PubMed

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

    2016-02-01

    A recent exome-sequencing study revealed prevalent mitogen-activated protein kinase 1 (MAPK1) p.E322K mutation in cervical carcinoma. It remains largely unknown whether ovarian carcinomas also harbor MAPK1 mutations. As paralogous gene mutations co‑occur frequently in human malignancies, we analyzed here a total of 263 ovarian carcinomas for the presence of MAPK1 and paralogous MAPK3 mutations by DNA sequencing. A previously unreported MAPK1 p.D321N somatic mutation was identified in 2 out of 18 (11.1%) ovarian mixed germ cell tumors, while no other MAPK1 or MAPK3 mutation was detected in our samples. Of note, OCC‑115, the MAPK1‑mutated sample with bilateral cancerous ovaries affected, harbored MAPK1 mutation in the right ovary while retained the left ovary intact, implicating that the genetic alterations underlying ovarian mixed germ cell tumor may be different, even in patients with similar genetic backgrounds and tumor microenvironments. The results of evolutionary conservation and protein structure modeling analysis implicated that MAPK1 p.D321N mutation may be pathogenic. Additionally, mutations in protein phosphatase 2 regulatory subunit α (PPP2R1A), ring finger protein 43 (RNF43), DNA directed polymerase ε (POLE1), ribonuclease type III (DICER1), CCCTC‑binding factor (CTCF), ribosomal protein L22 (RPL22), DNA methyltransferase 3α (DNMT3A), transformation/transcription domain‑associated protein (TRRAP), isocitrate dehydrogenase (IDH)1 and IDH2 were not detected in ovarian mixed germ cell tumors, implicating these genetic alterations may be not associated with MAPK1 mutation in the development of this malignancy. The present study identified a previously unreported MAPK1 mutation in ovarian mixed germ cell tumors for the first time, and this mutation may be actively involved in the tumorigenesis of this disease. PMID:26548627

  7. Evidence that the cAMP pathway controls emergence of both primary and appressorial germ tubes of barley powdery mildew.

    TOXLINE Toxicology Bibliographic Information

    Kinane J; Dalvin S; Bindslev L; Hall A; Gurr S; Oliver R

    2000-05-01

    Development of conidia of barley powdery mildew involves the formation of a primary germ tube (PGT), an appressorial germ tube (AGT), and an appressorium. Previously, it was found that cyclic AMP (cAMP) was involved in these developmental processes. Comparison of development on the host surface with two types of cellulose membrane revealed that frequency of PGT emergence was surface independent. On one type of cellulose, where the frequencies of both AGT and appressorial differentiation were similar to that on the host surface, cAMP levels and protein kinase A (PKA) activities had a biphasic pattern with peaks at 15 min and 4 h after inoculation (prior to PGT and AGT emergence, respectively). The effect of manipulating cAMP levels was tested on another type of cellulose membrane, which stimulated a lower degree of AGT and appressorial formation than the host surface. Cholera toxin and forskolin, activators of adenylyl cyclase, significantly increased PGT emergence, but cAMP did not. Cholera toxin, forskolin, and cAMP increased the frequency of AGT and appressorial formation, but in a time-dependent manner.

  8. Clinical efficacy of perceived 'CNS friendly' chemoradiotherapy for primary intracranial germ cell tumours.

    PubMed

    Plowman, P N; Kingston, J E; Sebag-Montefiore, D; Doughty, D

    1997-01-01

    The optimal treatment of intracranial germ cell tumours (IGCT) is controversial. The late sequelae of craniospinal radiotherapy and the high response rate to chemotherapy have led to new treatment strategies. The morbidity of combined modality therapy has tempered enthusiasm for aggressive chemoradiotherapy. In 1992, we described new lower morbidity chemotherapy and radiotherapy methods to be used in conjunction for IGCT treatment, employing three drugs (vincristine, carboplatin, etoposide) and a differential daily dose neuraxis radiotherapy technique (to replace a shrinking field technique). The chemoradiotherapy had the potential for a graded intensity reduction when high cure rates were maintained. Of 13 IGCT patients treated on this protocol, 8/8 germinomatous GCT and 3/5 non-germinomatous GCTs are in continuing remission. These observations have implications for other CNS tumour treatments in (young) patients, in whom late CNS toxicity (particularly neuropsychological) is a problem. PMID:9039814

  9. The clinical characteristics and treatment outcome of 57 children and adolescents with primary central nervous system germ cell tumors

    PubMed Central

    Sun, Xiao-Fei; Zhang, Fei; Zhen, Zi-Jun; Yang, Qun-Ying; Xia, Yun-Fei; Wu, Shao-Xiong; Zhu, Jia; Lu, Su-Ying; Wang, Juan; Sun, Fei-Fei; Cai, Rui-Qing; Chen, Yan; Li, Peng-Fei

    2014-01-01

    Primary central nervous system germ cell tumors (CNS-GCTs) in children and adolescents have unique clinical features and methods of treatment compared with those in adults. There is little information about Chinese children and adolescents with CNS-GCTs. Therefore, in this study we retrospectively analyzed the clinical features and treatment outcome of Chinese children and adolescents with primary CNS-GCTs. Between January 2002 and December 2012, 57 untreated patients from a single institution were enrolled. They were diagnosed with CNS-GCTs after pathologic or clinical assessment. Of the 57 patients, 41 were males and 16 were females, with a median age of 12.8 years (range, 2.7 to 18.0 years) at diagnosis; 43 (75.4%) had non-germinomatous germ cell tumors (NGGCTs) and 14 (24.6%) had germinomas; 44 (77.2%) had localized disease and 13 (22.8%) had extensive lesions. Fifty-three patients completed the prescribed treatment, of which 18 underwent monotherapy of surgery, radiotherapy, or chemotherapy, and 35 underwent multimodality therapies that included radiotherapy combined with chemotherapy or surgery combined with chemotherapy and/or radiotherapy. PEB (cisplatin, etoposide, and bleomycin) protocol was the major chemotherapy regimen. The median follow-up time was 32.3 months (range, 1.2 to 139 months). Fourteen patients died of relapse or disease progression. The 3-year event-free survival (EFS) and overall survival rates for all patients were 72.2% and 73.8%, respectively. The 3-year EFS was 92.9% for germinomas and 64.8% for NGGCTs (P = 0.064). The 3-year EFS rates for patients with NGGCTs who underwent monotherapy and multimodality therapies were 50.6% and 73.5%, respectively (P = 0.042). Our results indicate that multimodality therapies including chemotherapy plus radiotherapy were better treatment option for children and adolescents with CNS-GCTs. PMID:25011460

  10. Transcriptional profiling of endogenous germ layer precursor cells identifies dusp4 as an essential gene in zebrafish endoderm specification

    PubMed Central

    Brown, Jamie L.; Snir, Mirit; Noushmehr, Houtan; Kirby, Martha; Hong, Sung-Kook; Elkahloun, Abdel G.; Feldman, Benjamin

    2008-01-01

    A major goal for developmental biologists is to define the behaviors and molecular contents of differentiating cells. We have devised a strategy for isolating cells from diverse embryonic regions and stages in the zebrafish, using computer-guided laser photoconversion of injected Kaede protein and flow cytometry. This strategy enabled us to perform a genome-wide transcriptome comparison of germ layer precursor cells. Mesendoderm and ectoderm precursors cells isolated by this method differentiated appropriately in transplantation assays. Microarray analysis of these cells reidentified known genes at least as efficiently as previously reported strategies that relied on artificial mesendoderm activation or inhibition. We also identified a large set of uncharacterized mesendoderm-enriched genes as well as ectoderm-enriched genes. Loss-of-function studies revealed that one of these genes, the MAP kinase inhibitor dusp4, is essential for early development. Embryos injected with antisense morpholino oligonucleotides that targeted Dusp4 displayed necrosis of head tissues. Marker analysis during late gastrulation revealed a specific loss of sox17, but not of other endoderm markers, and analysis at later stages revealed a loss of foregut and pancreatic endoderm. This specific loss of sox17 establishes a new class of endoderm specification defect. PMID:18719100

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

    PubMed

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

    2012-09-01

    Intracranial germ cell tumors (GCTs) are relatively rare. Their incidence has been considered to be higher in East Asia than in the United States. This study estimates the incidence of CNS GCTs in Japan and the United States, investigates gender discrepancies in each country, and describes treatment outcomes. Data on primary CNS GCTs from 4 databases were utilized: population-based malignant incidence data from (1) the Japan Cancer Surveillance Research Group (2004-2006; 14 registries), malignant and nonmalignant incidence data from (2) the Surveillance, Epidemiology, and End Results Program (2004-2008; 17 registries), and hospital-based observed survival data from (3) the Brain Tumor Registry of Japan (1984-2000) and (4) the US National Cancer Data Base (1990-2003). Incidence rates per 100 000 for malignant GCTs were not statistically significantly different between Japan (males = 0.143, females = 0.046) and the United States (males = 0.118, females = 0.030). The malignant incidence-rate ratio was higher for pineal GCTs versus nonpineal (ie, the rest of the brain) GCTs in Japan (11.5:1 vs 1.9:1, respectively) and the United States (16.0:1 vs 1.7:1, respectively). In general, 5-year survival estimates were high: over 75% for all GCTs, and over 81% for germinomas, regardless of the type of treatment in either Japan or the United States. The incidence of primary GCTs is similar between Japan and the United States and has the same gender-based patterns by location. High rates of survival were observed in both countries. PMID:22869621

  12. The zebrafish tailbud contains two independent populations of midline progenitor cells that maintain long-term germ layer plasticity and differentiate in response to local signaling cues.

    PubMed

    Row, Richard H; Tsotras, Steve R; Goto, Hana; Martin, Benjamin L

    2016-01-15

    Vertebrate body axis formation depends on a population of bipotential neuromesodermal cells along the posterior wall of the tailbud that make a germ layer decision after gastrulation to form spinal cord and mesoderm. Despite exhibiting germ layer plasticity, these cells never give rise to midline tissues of the notochord, floor plate and dorsal endoderm, raising the question of whether midline tissues also arise from basal posterior progenitors after gastrulation. We show in zebrafish that local posterior signals specify germ layer fate in two basal tailbud midline progenitor populations. Wnt signaling induces notochord within a population of notochord/floor plate bipotential cells through negative transcriptional regulation of sox2. Notch signaling, required for hypochord induction during gastrulation, continues to act in the tailbud to specify hypochord from a notochord/hypochord bipotential cell population. Our results lend strong support to a continuous allocation model of midline tissue formation in zebrafish, and provide an embryological basis for zebrafish and mouse bifurcated notochord phenotypes as well as the rare human congenital split notochord syndrome. We demonstrate developmental equivalency between the tailbud progenitor cell populations. Midline progenitors can be transfated from notochord to somite fate after gastrulation by ectopic expression of msgn1, a master regulator of paraxial mesoderm fate, or if transplanted into the bipotential progenitors that normally give rise to somites. Our results indicate that the entire non-epidermal posterior body is derived from discrete, basal tailbud cell populations. These cells remain receptive to extracellular cues after gastrulation and continue to make basic germ layer decisions. PMID:26674311

  13. A shift in germ layer allocation is correlated with large egg size and facultative planktotrophy in the echinoid Clypeaster rosaceus.

    PubMed

    Zigler, Kirk S; Raff, Rudolf A

    2013-08-01

    Egg size is a correlate of larval evolution in marine embryos. Comparing species with different egg sizes that develop via similar larvae reveals the flexibility and the constraints underlying larval forms. Clypeaster rosaceus is an echinoid that develops via a facultatively planktotrophic pluteus larva. Unlike most echinoids that develop via plutei, C. rosaceus (1) has a larger egg, with a correspondingly smaller ratio of surface area to volume, and (2) forms a large left coelom early in development. Given these characteristics, we predicted underlying changes in the allocation of embryonic tissues to germ layers. With a low surface-to-volume ratio, the C. rosaceus pluteus likely requires relatively less ectoderm than a typical pluteus, whereas the early formation of a large left coelom likely requires relatively more mesoderm than a typical pluteus. We tested this hypothesis by examining the cell lineage of C. rosaceus. We found that the boundary between ectoderm and endoderm in C. rosaceus has shifted relative to echinoids with more typical planktotrophic plutei and extends to or above the third cleavage plane at the equator of the embryo. This indicates a smaller proportional allocation to ectoderm and a larger proportional allocation to endomesoderm compared to echinoids with smaller egg sizes. On the basis of this observation, we develop a new model for the transition from obligate planktotrophy to lecithotrophy. We argue that species with larger eggs may allocate proportionally more tissue to structures selected for accelerated development. In the case of C. rosaceus, the larval cell lineage apportions more cells to endomesoderm and less to ectoderm due to the smaller surface-to-volume ratio of its larger eggs and the early formation of a large left coelom. PMID:23995743

  14. Differentiation potential of germ line stem cells derived from the postnatal mouse ovary.

    PubMed

    Pacchiarotti, Jason; Maki, Chad; Ramos, Thomas; Marh, Joel; Howerton, Kyle; Wong, Jadelind; Pham, Jane; Anorve, Sandra; Chow, Yung-Chiong; Izadyar, Fariborz

    2010-03-01

    General belief in reproductive biology is that in most mammals female germ line stem cells are differentiated to primary oocytes during fetal development and oogenesis starts from a pool of primordial follicles after birth. This idea has been challenged previously by using follicle kinetics studies and demonstration of mitotically active germ cells in the postnatal mouse ovary (Johnson et al., 2004; Kerr et al., 2006; Zhang et al., 2008). However, the existence of a population of self-renewing ovarian germ line stem cells in postnatal mammals is still controversial (Eggan et al., 2006; Telfer et al., 2005; Gosden, 2004). Recently, production of offspring from a germ line stem cell line derived from the neonatal mouse ovary was reported (Zou et al., 2009). This report strongly supports the existence of germ line stem cells and their ability to expand in vitro. Recently, using a transgenic mouse model in which GFP is expressed under a germ cell-specific Oct-4 promoter, we isolated and generated multipotent cell lines from male germ line stem cells (Izadyar et al., 2008). Using the same strategy we isolated and derived cell lines from postnatal mouse ovary. Interestingly, ovarian germ line stem cells expanded in the same culture conditions as the male suggesting that they have similar requirements for their self-renewal. After 1 year of culture and many passages, ovarian germ line stem cells maintained their characteristics and telomerase activity, expressed germ cell and stem cell markers and revealed normal karyotype. As standard protocol for differentiation induction, these cells were aggregated and their ability to form embryoid bodies (EBs) was investigated. EBs generated in the presence of growth factors showed classical morphology and expressed specific markers for three germ layers. However, in the absence of growth promoting factors EBs were smaller and large cells with the morphological and molecular characteristics of oocytes were formed. This study shows the existence of a population of germ line stem cell in postnatal mouse ovary with multipotent characteristics. PMID:20138422

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

    PubMed

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

    2014-11-01

    Upon removal of culture conditions that maintain an undifferentiated state, mouse embryonic stem cells (ESCs) differentiate into various cell types. Differentiation can be facilitated by forced expression of certain transcription factors (TFs), each of which can generally specify a particular developmental lineage. We previously established 137 mouse ESC lines, each of which carried a doxycycline-controllable TF. Among them, Sox9 has unique capacity: its forced expression accelerates differentiation of mouse ESCs into cells of all three germ layers. With the additional use of specific culture conditions, overexpression of Sox9 facilitated the generation of endothelial cells, hepatocytes and neurons from ESCs. Furthermore, Sox9 action increases formation of p21 (WAF1/CIP1), which then binds to the SRR2 enhancer of pluripotency marker Sox2 and inhibits its expression. Knockdown of p21 abolishes inhibition of Sox2 and Sox9-accelerated differentiation, and reduction of Sox2 2 days after the beginning of ESC differentiation can comparably accelerate mouse ESC formation of cells of three germ layers. These data implicate the involvement of the p21-Sox2 pathway in the mechanism of accelerated ESC differentiation by Sox9 overexpression. The molecular cascade could be among the first steps to program ESC differentiation. PMID:25371362

  16. Differential requirement for the dual functions of β-catenin in embryonic stem cell self-renewal and germ layer formation

    PubMed Central

    Lyashenko, Natalia; Winter, Markus; Migliorini, Domenico; Biechele, Travis; Moon, Randall T.; Hartmann, Christine

    2011-01-01

    Canonical Wnt-signalling has been implicated in mouse and human embryonic stem cell (ESC) maintenance, however its requirement is controversial. β-catenin is the key component in this highly conserved Wnt pathway, acting as a transcriptional transactivator. Yet, β-catenin has additional roles at the plasma membrane regulating cell-cell adhesion, complicating the analyses of cells/tissues lacking β-catenin. We report here the generation of a β-catenin deficient mouse ESC (mESC) line and show that self-renewal is maintained in absence of β-catenin. Cell-adhesion is partially rescued by plakoglobin up-regulation, but fails to be maintained during differentiation. When differentiated as aggregates, wild-type mESCs form descendents of all three germ layers, while mesendodermal germ layer formation and neuronal differentiation are defective in β-catenin deficient mESCs. A Tcf/Lef-signalling defective β-catenin variant, which re-establishes cadherin-mediated cell-adhesion, rescues definitive endoderm and neuroepithelial formation, suggesting that β-catenin cell-adhesion function is more important than its signalling function for these processes. PMID:21685890

  17. Non-primary layering in some Adirondack orthogneisses

    SciTech Connect

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

    1993-03-01

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

  18. DNA Methylation Is the Primary Silencing Mechanism for a Set of Germ Line- and Tumor-Specific Genes with a CpG-Rich Promoter

    PubMed Central

    De Smet, Charles; Lurquin, Christophe; Lethé, Bernard; Martelange, Valérie; Boon, Thierry

    1999-01-01

    A subset of male germ line-specific genes, the MAGE-type genes, are activated in many human tumors, where they produce tumor-specific antigens recognized by cytolytic T lymphocytes. Previous studies on gene MAGE-A1 indicated that transcription factors regulating its expression are present in all tumor cell lines whether or not they express the gene. The analysis of two CpG sites located in the promoter showed a strong correlation between expression and demethylation. It was also shown that MAGE-A1 transcription was induced in cell cultures treated with demethylating agent 5?-aza-2?-deoxycytidine. We have now analyzed all of the CpG sites within the 5? region of MAGE-A1 and show that for all of them, demethylation correlates with the transcription of the gene. We also show that the induction of MAGE-A1 with 5?-aza-2?-deoxycytidine is stable and that in all the cell clones it correlates with demethylation, indicating that demethylation is necessary and sufficient to produce expression. Conversely, transfection experiments with in vitro-methylated MAGE-A1 sequences indicated that heavy methylation suffices to stably repress the gene in cells containing the transcription factors required for expression. Most MAGE-type genes were found to have promoters with a high CpG content. Remarkably, although CpG-rich promoters are classically unmethylated in all normal tissues, those of MAGE-A1 and LAGE-1 were highly methylated in somatic tissues. In contrast, they were largely unmethylated in male germ cells. We conclude that MAGE-type genes belong to a unique subset of germ line-specific genes that use DNA methylation as a primary silencing mechanism. PMID:10523621

  19. 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)

  20. Germ Cell Differentiation from Pluripotent Cells

    PubMed Central

    Medrano, Jose V.; Pera, Renee A. Reijo; Simón, Carlos

    2014-01-01

    Infertility is a medical condition with an increasing impact in Western societies with causes linked to toxins, genetics, and aging (primarily delay of motherhood). Within the different pathologies that can lead to infertility, poor quality or reduced quantity of gametes plays an important role. Gamete donation and therefore demand on donated sperm and eggs in fertility clinics is increasing. It is hoped that a better understanding of the conditions related to poor gamete quality may allow scientists to design rational treatments. However, to date, relatively little is known about human germ cell development in large part due to the inaccessibility of human development to molecular genetic analysis. It is hoped that pluripotent human embryonic stem cells and induced pluripotent stem cells may provide an accessible in vitro model to study germline development; these cells are able to differentiate to cells of all three primary embryonic germ layers, as well as to germ cells in vitro. We review the state of the art in germline differentiation from pluripotent stem cells. PMID:23329632

  1. A new method for isolating primary mesenchyme cells of the sea urchin embryo. Panning on wheat germ agglutinin-coated dishes.

    PubMed

    Ettensohn, C A; McClay, D R

    1987-02-01

    This paper describes a rapid and efficient way to isolate primary mesenchyme cells (PMCs) of the sea urchin embryo. The procedure involves three simple steps: Dissociation of mesenchyme blastulae in calcium-free artificial seawater. Incubation of the resulting cell suspension on dishes that have been coated with wheat germ agglutinin (WGA), to which the PMCs adhere more firmly than do other cell types. Gentle rinsing of the dishes to remove loosely attached cells, followed by more vigorous rinsing to remove PMCs. This panning procedure has been applied to embryos of three species of sea urchins, Lytechinus variegatus, L. pictus and Arbacia punctulata, and yields populations of PMCs that are 95-99% pure as determined by the proportion of cells that stain with fluorescein isothiocynate (FITC)-WGA and with a monoclonal antibody that binds specifically to PMCs. The yield of PMCs is 4-5 X 10(6) cells/100-mm dish, or 1-2 X 10(7) PMCs/ml of packed embryos. The principal advantages of this procedure are that it can be carried out rapidly and simply, and it yields pure populations of PMCs. PMID:3803448

  2. Role of radiotherapy in treating patients with primary malignant mediastinal non-seminomatous germ cell tumor: A 21-year experience at a single institution

    PubMed Central

    Wang, Jianyang; Bi, Nan; Wang, Xiaozhen; Hui, Zhouguang; Liang, Jun; Lv, Jima; Zhou, Zongmei; Feng, Qin Fu; Xiao, Zefen; Chen, Dongfu; Zhang, Hongxing; Yin, Weibo; Wang, Luhua

    2015-01-01

    Background The aim of this study was to investigate the clinical characteristics and outcomes of patients with primary malignant mediastinal non-seminomatous germ cell tumor (MMNSGCT) by comparing the efficacies of different treatment modalities. Methods The charts of 62 consecutive patients with MMNSGCT between 1990 and 2010 were reviewed. Analyses included Kaplan-Meier survival and Cox multivariate regression. Results There was sufficient data of 61 patients for inclusion in the study. The median age was 25 years. At diagnosis, 35 patients had tumors located in the mediastinum, 26 had lung and/or distant metastases. At a median follow-up of 47.2 months, 32 patients had died and 43 had developed progressive disease. The one, three, and five-year overall survival (OS) and progression-free survival (PFS) rates were 72.1%, 50.8%, 49.2% and 47.5%, 32.8%, 32.8%, respectively. Patients who received radiotherapy in the primary treatment regimen showed improved five-year OS (68.2% vs. 38.5%, P?=?0.043), PFS (45.5% vs. 20.5%, P?=?0.023), and local recurrence-free survival (LRFS) (77.3% vs. 38.5%, P?=?0.003) compared with those who did not receive radiotherapy. Multivariate analysis revealed that radiotherapy was an independent prognostic factor of five-year OS (hazard ratio [HR] 0.39, P?=?0.037), PFS (HR 0.42, P?=?0.017), and LRFS (HR 0.31, P?=?0.019). Conclusion Radiotherapy in a chemotherapy-based treatment regimen could significantly reduce local recurrence and improve survival of MMNGCT patients. PMID:26273393

  3. The shallow oxygen maximum layer and primary production

    NASA Astrophysics Data System (ADS)

    Hayward, Thomas L.

    1994-03-01

    The shallow oxygen maximum (SOM) is a vertical maximum in the dissolved oxygen concentration of the upper ocean. This feature develops largely from photosynthetic oxygen production, and measurement of the rate of oxygen accumulation provides the basis to make an independent estimate of primary production. Net accumulation of dissolved oxygen represents new production, which is generally presumed to require a new nutrient input consisting of some form of preformed nutrients. Here the time scales, vertical distribution or properties and new nutrient sources associated with formation of the SOM in the North Pacific ocean area considered. The SOM forms on two distinct time scales, episodic and gradual, and apparently through different processes on each scale. The episodic SOM develops from physical events in which nutricline water is transported into the mixed layer and then ventilated to the atmosphere. This process results in the local creation of preformed nutrients that stimulate a phytoplankton bloom and a vertical maximum of chlorophyll and dissolved oxygen. However, the time scale of formation of the gradual SOM is inconsistent with this mechanism because repeated mixing and ventilation events cannot result in the gradual accumulation of oxygen. An alternative new nutrient source is required. It is hypothesized that the gradual SOM develops from input of the "new" nutrients contained in organic matter transported from other depths by migrating animals and/or sinking particles. This hypothesis implies that the concept of new production must be carefully defined in context of the vertical structure of the euphotic zone. Whether or not my hypothesis is correct, these observations show that estimating primary production by measuring the increase in dissolved oxygen is very difficult. For both the episodic and gradual SOM, estimating production requires that the gas fluxes due to air-sea exchange and vertical and horizontal mixing be well known, in addition to direct measurements of the temporal change in dissolved oxygen within a water parcel.

  4. [Reconsidering the roles of female germ cells in ovarian development and folliculogenesis].

    PubMed

    Guigon, Céline J; Cohen-Tannoudji, Michel

    2011-01-01

    The production of fertilizable ova is the consequence of multiple events that start as soon as ovarian development and culminate at the time of ovulation. Throughout their development, germ cells are associated with companion somatic cells, which ensure germ cell survival, growth and maturation. Data obtained in vitro and in vivo on several animal models of germ cell depletion have led to uncover the many roles of germ cells on both ovarian development and folliculogenesis. During ovarian development, germ cells become progressively enclosed within epithelial structures called "ovigerous cords" constituted by pregranulosa cells, lined by a basement membrane. At the end of ovarian development, ovigerous cords fragment into primordial follicles, which are epithelial units constituted by an oocyte surrounded by a single layer of granulosa cells. Germ cells are necessary for the fragmentation of ovigerous cords into follicles, since in their absence, no follicle will form. Germ cells also ensure the differentiation of the ovarian somatic lineage, and they may inhibit the testis-differentiating pathway by preventing the conversion of pregranulosa cells into Sertoli cells, their counterpart in the testis. Regularly, primordial follicles are recruited into the growing follicle pool and initiate their growth. They develop through primary, preantral, antral and preovulatory stages before being ovulated. Interestingly, the action of the oocyte on companion somatic cells tightly depends on the follicular stage. In primordial follicles, the oocyte prevents the transdifferentiation of granulosa cells into cells resembling Sertoli cells. By contrast, as soon as the follicle enters growth, the oocyte regulates the functional differentiation of granulosa cells and at the latest stages, it prevents their premature maturation into luteal cells. Overall, these data demonstrate that the female germ cell act on companion somatic cells to regulate ovarian development and folliculogenesis, thereby actively supporting its own maturation. PMID:22251857

  5. 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

  6. Dissecting Germ Cell Metabolism through Network Modeling

    PubMed Central

    Whitmore, Leanne S.; Ye, Ping

    2015-01-01

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

  7. Influence of flow properties on a structure of a mineral wool primary layer

    SciTech Connect

    Bajcar, Tom; Blagojevic, Bogdan; Sirok, Brane; Dular, Matevz

    2007-11-15

    Mineral wool primary layer formation is influenced by the aerodynamic characteristics of the blow-away airflow and the secondary surrounding airflow. The distribution of mineral wool fibres in the primary layer was determined experimentally using a computer-aided visualization method. The flow properties in the region where the primary layer is formed were analysed. Numerical simulations with experiment-based boundary conditions were performed. The numerically obtained profile of mineral wool thickness at the collection chamber outlet agreed with the results of the experiment. Presented numerical model confirms that the forming of the primary layer is significantly dependent on local aerodynamic characteristic of the airflow in the collection chamber. Interaction between the local anomalies on the forming layer and the corresponding aerodynamic effects in the surrounding region was also analysed. (author)

  8. 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

  9. What Are Germs?

    MedlinePLUS

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

  10. Fish germ cells.

    PubMed

    Xu, HongYan; Li, MingYou; Gui, JianFang; Hong, YunHan

    2010-04-01

    Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplantation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology. PMID:20596909

  11. Embryonic germ cell lines and their derivation from mouse primordial germ cells.

    PubMed

    Labosky, P A; Barlow, D P; Hogan, B L

    1994-01-01

    When primordial germ cells of the mouse are cultured on feeder layers with the addition of the polypeptide signalling molecules leukaemia inhibitory factor, Steel factor and basic fibroblast growth factor they give rise to cells that resemble undifferentiated blastocyst-derived embryonic stem cells. These primordial germ cell-derived embryonic germ cells (EG cells) can be induced to differentiate extensively in culture and also form teratocarcinomas when injected into nude mice. Additionally, they contribute to chimeras when injected into host blastocysts. We have derived multiple EG cell lines from 8.5 days post coitum (dpc) embryos of C57BL/6 inbred mice. Four independent EG cell lines with normal male karyotypes have formed chimeras (up to 70% coat colour chimerism) when injected into BALB/c host blastocysts. Chimeric mice from all four cell lines are fertile, but only those from one line have transmitted coat colour markers through the germline. Studies have also been carried out to determine whether gonadal primordial germ cells can give rise to pluripotent EG cells. Germ cells from gonads of 15.5 dpc C57BL/6 embryos and newborn mice failed to produce EG cell lines. EG cell lines capable of forming teratocarcinomas and coat colour chimeras have been established from primordial germ cells of 12.5 dpc genital ridges. We are currently testing the genomic imprinting status of the insulin-like growth factor type 2 receptor gene (Igf2r) in our different EG cell lines. PMID:7835148

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  14. Stages of Childhood Extracranial Germ Cell Tumors

    MedlinePLUS

    ... Extracranial Germ Cell Tumors Treatment Childhood Extracranial Germ Cell Tumors Treatment–Patient Version (PDQ®) General Information About Childhood Extracranial Germ Cell Tumors Key Points Childhood extracranial germ cell tumors ...

  15. Treatment Option Overview (Extragonadal Germ Cell Tumors)

    MedlinePLUS

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

  16. General Information about Extragonadal Germ Cell Tumors

    MedlinePLUS

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

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

    NASA Astrophysics Data System (ADS)

    Brock, John; Sathyendranath, Shubha; Platt, Trevor

    1994-06-01

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

  18. AiGERM: A logic programming front end for GERM

    NASA Technical Reports Server (NTRS)

    Hashim, Safaa H.

    1990-01-01

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

  19. Germs and Hygiene

    MedlinePLUS

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  1. Laminin receptors on Candida albicans germ tubes.

    PubMed Central

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

    1990-01-01

    Recent evidence for the role of laminin in cell adhesion and in the pathogenesis of several bacterial infections has led us to investigate the existence of receptors for this extracellular matrix component in Candida albicans. At first, immunofluorescence demonstrated the presence of laminin-binding sites at the surface of germ tubes. Electron microscopy confirmed this result and permitted precise localization of the binding sites on the outermost fibrillar layer of the germ tube cell wall. By using 125I-radiolabeled laminin, the binding was shown to be saturable and specific, hence demonstrating characteristics of true receptors. Analysis of the data by the Scatchard equation indicated that there were about 8,000 binding sites per cell, with a dissociation constant (Kd) of 1.3 x 10(-9) M. Binding was inhibited by prior heating or trypsinization of cells. Furthermore, of the different proteins and carbohydrates tested in competition experiments, only fibrinogen greatly reduced the laminin binding. Finally, dithiothreitol and iodoacetamide treatment of germ tubes allowed us to identify the laminin receptors through analysis of this extract by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblotting. Two components, of 68 kilodaltons and a doublet of 60 and 62 kilodaltons, were detected. Thus, C. albicans possesses germ tube-specific surface receptors for laminin which could mediate its attachment to basement membranes and so contribute to the establishment of candidiasis. Images PMID:2136734

  2. Energy distribution in white organic light-emitting diodes with three primary color emitting layers

    NASA Astrophysics Data System (ADS)

    Meng, LingChuan; Lou, ZhiDong; Yang, ShengYi; Deng, ZhaoRu

    2011-01-01

    Two types of organic light-emitting diodes with structures of ITO/ N, N'-bis(1-naphthyl)- N, N'-diphenyl,1,1'-biphenyl-4,4'-diamine (NPB)/tris(8-hydroquinolinato)aluminum(Alq3)/2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline(BCP)/Alq3:4-dicyanome-thylene-2-(tert-butyl)-6-methyl-4H-pyran(DCJTB)/Alq3/Al and ITO/NPB/BCP/Alq3/Alq3:DCJTB/Alq3/Al were studied. NPB was chosen as a hole-transporting/blue-emitting layer. Alq3 adjacent to BCP acted as a green emitting layer while that adjacent to the Al cathode acted as an electron-transporting layer. Alq3 doped with 2 wt.% DCJTB was used as a red emitting layer. The operating principles of the devices were explained by the mechanism of Förster energy transfer and the hole and exciton blocking effect of BCP. It was found that the spectral characteristics of the devices strongly depended on the relative location between the green emitting Alq3 layer and the BCP layer, as well as their thickness. Pure white emission with the CIE coordinates of (0.33, 0.33) was achieved by mixing the three primary colors in the device with the structure of ITO/NPB(30 nm)/ BCP(6 nm)/Alq3(30 nm)/Alq3:DCJTB(30 nm)/Alq3(30 nm)/Al. The BCP layer played an important role in distributing the exciton energy among the three emitting layers to achieve a balanced white light. The white emission of this device was largely insensitive to the driving voltage (15-27 V) with the insertion of the green emitting Alq3 layer.

  3. The Photo-Gravitational R3BP when the Primaries are Heterogeneous Spheroid with Three Layers

    NASA Astrophysics Data System (ADS)

    Suraj, Md Sanam; Hassan, M. R.; Asique, Md Chand

    2014-12-01

    The present paper deals with the stationary solution of the planar restricted three body problem when both the primaries are heterogeneous oblate spheroid with three layers of different densities and sources of radiation as well. It derives equations of motion and examines the existence and the linear stability of libration points. It is seen that there are five libration points, two triangular points and three collinear ones. It is further observed that the collinear points are unstable, while the triangular points are stable for the mass parameter 0 ? ? < ? c r i t . Here ? c r i t (the critical mass parameter) depends upon the combined effects of radiation and that due to the three different layers in the primaries. It is further seen that long or short periodic elliptical orbits emanate from the triangular points in the aforementioned range of ?.

  4. Germ Cell Intercellular Bridges

    PubMed Central

    Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

    2011-01-01

    Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

  5. Primary structure and glycosylation of the S-layer protein of Haloferax volcanii.

    PubMed Central

    Sumper, M; Berg, E; Mengele, R; Strobel, I

    1990-01-01

    The outer surface of the archaebacterium Haloferax volcanii (formerly named Halobacterium volcanii) is covered with a hexagonally packed surface (S) layer. The gene coding for the S-layer protein was cloned and sequenced. The mature polypeptide is composed of 794 amino acids and is preceded by a typical signal sequence of 34 amino acid residues. A highly hydrophobic stretch of 20 amino acids at the C-terminal end probably serves as a transmembrane domain. Clusters of threonine residues are located adjacent to this membrane anchor. The S-layer protein is a glycoprotein containing both N- and O-glycosidic bonds. Glucosyl-(1----2)-galactose disaccharides are linked to threonine residues. The primary structure and the glycosylation pattern of the S-layer glycoproteins from Haloferax volcanii and from Halobacterium halobium were compared and found to exhibit distinct differences, despite the fact that three-dimensional reconstructions from electron micrographs revealed no structural differences at least to the 2.5-nm level attained so far (M. Kessel, I. Wildhaber, S. Cohe, and W. Baumeister, EMBO J. 7:1549-1554, 1988). Images PMID:2123862

  6. Spatial organization of excitatory synaptic inputs to layer 4 neurons in mouse primary auditory cortex

    PubMed Central

    Kratz, Megan B.; Manis, Paul B.

    2015-01-01

    Layer 4 (L4) of primary auditory cortex (A1) receives a tonotopically organized projection from the medial geniculate nucleus of the thalamus. However, individual neurons in A1 respond to a wider range of sound frequencies than would be predicted by their thalamic input, which suggests the existence of cross-frequency intracortical networks. We used laser scanning photostimulation and uncaging of glutamate in brain slices of mouse A1 to characterize the spatial organization of intracortical inputs to L4 neurons. Slices were prepared to include the entire tonotopic extent of A1. We find that L4 neurons receive local vertically organized (columnar) excitation from layers 2 through 6 (L6) and horizontally organized excitation primarily from L4 and L6 neurons in regions centered ~300–500 ?m caudal and/or rostral to the cell. Excitatory horizontal synaptic connections from layers 2 and 3 were sparse. The origins of horizontal projections from L4 and L6 correspond to regions in the tonotopic map that are approximately an octave away from the target cell location. Such spatially organized lateral connections may contribute to the detection and processing of auditory objects with specific spectral structures. PMID:25972787

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

    PubMed

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

    2015-11-18

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

  8. 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. ...

  9. 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

  10. Palifosfamide in Treating Patients With Recurrent Germ Cell Tumors

    ClinicalTrials.gov

    2015-06-11

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

  11. Do retroperitoneal extragonadal germ cell tumours exist?

    PubMed Central

    Punjani, Nahid; Winquist, Eric; Power, Nicholas

    2015-01-01

    Introduction: Extragonadal germ cell tumours (GCTs) have been described arising in midline structures. Although primary retroperitoneal extragonadal GCTs (RPGCTs) comprise 30% to 40% of these, their existence as a genuine disease has been questioned. Our study evaluated clinicopathological findings to examine this question in RPGCT patients at our centre. Methods: Data from 414 men between 1980 and 2014 treated at London Health Sciences Centre with chemotherapy for testicular GCTs were reviewed retrospectively. Primary RPGCT was defined as pathologically diagnosed GCT with no evidence of GCT in the testes by physical exam or ultrasound. Patients thought to have primary RPGCT at the time of initial diagnosis were identified from an electronic database and data were extracted. Results: In total, 18 men with a diagnosis of metastatic RPGCT were identified. Four were excluded due to ultrasound reports that were incomplete or suggested malignancy. The remaining 14 patients had negative or non-specific ultrasounds, and all received platinum-based combination chemotherapy. Ten patients (71%) underwent post-chemotherapy RP lymph node dissections; of those 8 (57%) who underwent orchiectomy, none had corresponding pathologically normal testicular tissue. Conclusion: RPGCT patients present with more advanced disease stage. Our study sample size is limited, but the findings are consistent with existing literature suggesting that primary RPGCTs may not exist as a unique disease, but instead may represent metastatic disease from a clinically occult testicular primary. By corollary, viable malignant germ cells may be present in testes of patients with presumed primary RPGCT, and may persist as a site of residual malignant disease after chemotherapy. PMID:26788225

  12. Local Slow Waves in Superficial Layers of Primary Cortical Areas during REM Sleep.

    PubMed

    Funk, Chadd M; Honjoh, Sakiko; Rodriguez, Alexander V; Cirelli, Chiara; Tononi, Giulio

    2016-02-01

    Sleep is traditionally constituted of two global behavioral states, non-rapid eye movement (NREM) and rapid eye movement (REM), characterized by quiescence and reduced responsiveness to sensory stimuli [1]. NREM sleep is distinguished by slow waves and spindles throughout the cerebral cortex and REM sleep by an "activated," low-voltage fast electroencephalogram (EEG) paradoxically similar to that of wake, accompanied by rapid eye movements and muscle atonia. However, recent evidence has shown that cortical activity patterns during wake and NREM sleep are not as global as previously thought. Local slow waves can appear in various cortical regions in both awake humans [2] and rodents [3-5]. Intracranial recordings in humans [6] and rodents [4, 7] have shown that NREM sleep slow waves most often involve only a subset of brain regions that varies from wave to wave rather than occurring near synchronously across all cortical areas. Moreover, some cortical areas can transiently "wake up" [8] in an otherwise sleeping brain. Yet until now, cortical activity during REM sleep was thought to be homogenously wake-like. We show here, using local laminar recordings in freely moving mice, that slow waves occur regularly during REM sleep, but only in primary sensory and motor areas and mostly in layer 4, the main target of relay thalamic inputs, and layer 3. This finding may help explain why, during REM sleep, we remain disconnected from the environment even though the bulk of the cortex shows wake-like, paradoxical activation. PMID:26804554

  13. 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.

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

    PubMed

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

    2016-02-01

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

  15. Layer specific sharpening of frequency tuning by selective attention in primary auditory cortex.

    PubMed

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

    2014-12-01

    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

  16. 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

  17. [Functional state of the cortical and medullary layers of the adrenals in primary arterial hypotension].

    PubMed

    Man'shikov, V V; Rudo?, B D; Bol'shakova, T D; Shekhter, I M; Lukicheva, T I

    1976-11-01

    The functional state of the cortical and medullar layers of the adrenal glands was studied in 127 patients with primary arterial hypotension (109 females and 18 males, aged 17 to 48 years). As shown by daily urine excretion, hypotonic patients had a decreased basal activity of the glucocorticoid and androgenic function of the adrenal cortex in comparison with those in normal individuals. The potential of the adrenal cortex was preserved in these patients within sufficient limits. The adrenocorticotrophic function of the anterior lobe of the pituitary gland was found to decrease. Against the background of a reduction of the total excretion of all fractions a relative delay was noted in the process of glucocorticoids transformation into their precursors, as well as a relative predominance of glucocorticoids over mineralcorticoids, the content of desoxycorticosterone being reduced especially low. The content of adrenalin, noradrenaline and dophamine was below the normal level, the decrease being statistically significant. At the same time the excretion of DOPA was normal, on the average, the whole group of patients. The changes in the daily urine excretion of catecholamines and DOPA, as well as in their ratio indicate that the activity of both links of the sympathodrenal system is reduced in primary arterial hypotension. PMID:189116

  18. 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

  19. Germ line imprinting in Drosophila: Epigenetics in search of function.

    PubMed

    Menon, Debashish U; Meller, Victoria H

    2010-01-01

    Germ line imprinting produces parent-specific differences in the behavior of chromosomes or expression of genes. Epigenetic marks, placed on chromosomes in the parental germ line, govern classical imprinted effects such as chromosomal inactivation, chromosome elimination and mono-allelic expression. Germ line imprinting occurs in insects, plants and mammals. Several Drosophila systems display imprinted effects. In spite of this, many aspects of imprinting in flies, including the normal function of this process, remain mysterious. Transgenerational inheritance of epigenetic marks is a powerful force in genome regulation. Elucidation of the mechanism of imprint establishment and maintenance in a model organism, such as Drosophila, is thus of great interest. In this review we summarize the primary systems that have been used to study imprinting in flies and speculate on the origin and biological function of imprinting in Drosophila. PMID:20081359

  20. Nuclear Reprogramming in Mouse Primordial Germ Cells: Epigenetic Contribution

    PubMed Central

    De Felici, Massimo

    2011-01-01

    The unique capability of germ cells to give rise to a new organism, allowing the transmission of primary genetic information from generation to generation, depends on their epigenetic reprogramming ability and underlying genomic totipotency. Recent studies have shown that genome-wide epigenetic modifications, referred to as “epigenetic reprogramming”, occur during the development of the gamete precursors termed primordial germ cells (PGCs) in the embryo. This reprogramming is likely to be critical for the germ line development itself and necessary to erase the parental imprinting and setting the base for totipotency intrinsic to this cell lineage. The status of genome acquired during reprogramming and the associated expression of key pluripotency genes render PGCs susceptible to transform into pluripotent stem cells. This may occur in vivo under still undefined condition, and it is likely at the origin of the formation of germ cell tumors. The phenomenon appears to be reproduced under partly defined in vitro culture conditions, when PGCs are transformed into embryonic germ (EG) cells. In the present paper, I will try to summarize the contribution that epigenetic modifications give to nuclear reprogramming in mouse PGCs. PMID:21969835

  1. Specification of the germ line.

    PubMed Central

    Strome, Susan

    2005-01-01

    In C. elegans, the germ line is set apart from the soma early in embryogenesis. Several important themes have emerged in specifying and guiding the development of the nascent germ line. At early stages, the germline blastomeres are maintained in a transcriptionally silent state by the transcriptional repressor PIE-1. When this silencing is lifted, it is postulated that correct patterns of germline gene expression are controlled, at least in part, by MES-mediated regulation of chromatin state. Accompanying transcriptional regulation by PIE-1 and the MES proteins, RNA metabolism in germ cells is likely to be regulated by perinuclear RNA-rich cytoplasmic granules, termed P granules. This chapter discusses the molecular nature and possible roles of these various germline regulators, and describes a recently discovered mechanism to protect somatic cells from following a germline fate. PMID:18050414

  2. General Information about Childhood Extracranial Germ Cell Tumors

    MedlinePLUS

    ... Extracranial Germ Cell Tumors Treatment Childhood Extracranial Germ Cell Tumors Treatment–Patient Version (PDQ®) General Information About Childhood Extracranial Germ Cell Tumors Key Points Childhood extracranial germ cell tumors ...

  3. Treatment Options for Childhood Extracranial Germ Cell Tumors

    MedlinePLUS

    ... Extracranial Germ Cell Tumors Treatment Childhood Extracranial Germ Cell Tumors Treatment–Patient Version (PDQ®) General Information About Childhood Extracranial Germ Cell Tumors Key Points Childhood extracranial germ cell tumors ...

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  5. Identification of Potential Germ-Cell Mutagens

    EPA Science Inventory

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

  6. 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...

  7. HISTORY OF GERM CELL MUTAGENESIS

    EPA Science Inventory

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

  8. 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…

  9. 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…

  10. Virus neutralization by germ-line vs. hypermutated antibodies

    PubMed Central

    Kalinke, Ulrich; Oxenius, Annette; López-Macías, Constantino; Zinkernagel, Rolf M.; Hengartner, Hans

    2000-01-01

    Mice infected with vesicular stomatitis virus (VSV), a cytopathic virus closely related to rabies virus, mount a virus-neutralizing antibody response protecting against lethal disease. VSVneutralizing monoclonal IgGs isolated from primary immune responses were devoid of somatic mutations, whereas most secondary and all hyperimmune response IgGs tested were hypermutated. A comparative analysis of recombinant single-chain antibody fragments (scFv-C?) revealed that even the germ-line precursor of one hypermutated antibody bound and neutralized VSV. Four somatic amino acid substitutions in VH increased by 300-fold the binding strength of monovalent scFv-C?. The multivalent binding avidity of germ-line scFv-C? was increased by more than 10-fold compared with the monovalent binding strength. In contrast, hypermutated scFv-C? did not show such avidity effects. Thus the overall binding difference between the germ-line and the hypermutated VSV-neutralizing antibody was only 10- to 15-fold. This may explain why primary germ-line antibodies and secondary hypermutated antibodies directed against pathogens such as viruses and bacteria expressing repetitive antibody determinants show rather similar binding qualities, whereas monovalently binding hapten-specific antibodies can show “affinity maturation” effects of up to 1000-fold. PMID:10963674

  11. 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

  12. The Geochemical Earth Reference Model (GERM)

    SciTech Connect

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

    1996-12-01

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

  13. Primordial Germ Cell Specification and Migration

    PubMed Central

    Marlow, Florence

    2015-01-01

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

  14. Primordial Germ Cells: Current Knowledge and Perspectives

    PubMed Central

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

    2016-01-01

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

  15. Primordial Germ Cells: Current Knowledge and Perspectives.

    PubMed

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

    2016-01-01

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

  16. Aerosol Measurements in the Atmospheric Surface Layer at L'Aquila, Italy: Focus on Biogenic Primary Particles

    NASA Astrophysics Data System (ADS)

    Pitari, Giovanni; Coppari, Eleonora; De Luca, Natalia; Di Carlo, Piero; Pace, Loretta

    2014-09-01

    Two year measurements of aerosol concentration and size distribution (0.25 ?m < d < 30 ?m) in the atmospheric surface layer, collected in L'Aquila (Italy) with an optical particle counter, are reported and analysed for the different modes of the particle size distribution. A different seasonal behaviour is shown for fine mode aerosols (largely produced by anthropogenic combustion), coarse mode and large-sized aerosols, whose abundance is regulated not only by anthropogenic local production, but also by remote natural sources (via large scale atmospheric transport) and by local sources of primary biogenic aerosols. The observed total abundance of large particles with diameter larger than 10 ?m is compared with a statistical counting of primary biogenic particles, made with an independent technique. Results of these two observational approaches are analysed and compared to each other, with the help of a box model driven by observed meteorological parameters and validated with measurements of fine and coarse mode aerosols and of an atmospheric primary pollutant of anthropogenic origin (NOx). Except in winter months, primary biogenic particles in the L'Aquila measurement site are shown to dominate the atmospheric boundary layer population of large aerosol particles with diameter larger than 10 ?m (about 80 % of the total during summer months), with a pronounced seasonal cycle, contrary to fine mode aerosols of anthropogenic origin. In order to explain these findings, the main mechanisms controlling the abundance and variability of particulate matter tracers in the atmospheric surface layer are analysed with the numerical box-model.

  17. Current urologic care for testicular germ cell tumors in pediatric and adolescent patients.

    PubMed

    Grantham, Erin C; Caldwell, Brian T; Cost, Nicholas G

    2016-02-01

    Testicular germ cell tumors make up 0.5% of pediatric malignancies, and 14% of adolescent malignancies. Young boys have primarily pure teratoma and pure yolk sac histologies; however, adolescent histology is mostly mixed nonseminomatous germ cell tumor. Surgical excision of the primary tumor is the crux of treatment. Chemotherapy, retroperitoneal lymph node dissection, and targeted treatment of distant metastases make even widely disseminated disease treatable. Since the discovery of platinum-based chemotherapy, testicular germ cell tumors are a highly curable disease. However, adolescents remain the group with the highest mortality. Focus has expanded beyond survival to emphasize quality of life issues when optimizing treatment algorithms. PMID:26187598

  18. Secondary ion emission from arachidic acid LB-layers under Ar +, Xe +, Ga + and SF 5+ primary ion bombardment

    NASA Astrophysics Data System (ADS)

    Stapel, D.; Brox, O.; Benninghoven, A.

    1999-02-01

    The influence of primary ion energy, mass and composition on sputtering and secondary ion emission of arachidic acid Langmuir-Blodgett mono- and multilayers, deposited on gold substrates, has been investigated. Ga +, Ar +, 129Xe+ and SF 5+ in the energy range 5-25 keV were used as primary ions. Yields Y, damage cross-sections ?, and ion formation efficiencies E have been determined for selected secondary ions, characterizing the molecular overlayer, the overlayer substrate interface and the substrate. We found a strong influence of layer thickness and of primary ion energy, mass and composition on Y, ? and E. Information depth increases with increasing ion energy and decreasing mass of primary ions, being higher for SF 5+ than for Xe +. Y, ? and E increase with increasing primary ion mass. They are considerably higher for a molecular (SF 5+) than for atomic ions of comparable mass ( 129Xe+). The experimental results supply information on the extension of impact cascades, generated in different substrate materials by different primary ion species and different energies. They demonstrate that in analytical SIMS application information depths can be minimized and yields and ion formation efficiencies can be maximized by the use of molecular primary ions.

  19. The dazzle in germ cell differentiation.

    PubMed

    Kerr, Candace L; Cheng, Linzhao

    2010-02-01

    Embryonic stem cells have demonstrated the capacity to differentiate into germ cells in vitro. Until recently, the molecular basis of early post-meiotic germ cell development was largely unknown. Now, two reports including one published here recently, have demonstrated the significant contribution of Dazl in the differentiation of embryonic stem cells into pre- and post-meiotic germ cells. Although factors that Dazl influences during this process have been identified, the underlying mechanisms warrant future studies. PMID:20008336

  20. 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

  1. 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.

  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. Selective Activation of the Deep Layers of the Human Primary Visual Cortex by Top-Down Feedback.

    PubMed

    Kok, Peter; Bains, Lauren J; van Mourik, Tim; Norris, David G; de Lange, Floris P

    2016-02-01

    In addition to bottom-up input, the visual cortex receives large amounts of feedback from other cortical areas [1-3]. One compelling example of feedback activation of early visual neurons in the absence of bottom-up input occurs during the famous Kanizsa illusion, where a triangular shape is perceived, even in regions of the image where there is no bottom-up visual evidence for it. This illusion increases the firing activity of neurons in the primary visual cortex with a receptive field on the illusory contour [4]. Feedback signals are largely segregated from feedforward signals within each cortical area, with feedforward signals arriving in the middle layer, while top-down feedback avoids the middle layers and predominantly targets deep and superficial layers [1, 2, 5, 6]. Therefore, the feedback-mediated activity increase in V1 during the perception of illusory shapes should lead to a specific laminar activity profile that is distinct from the activity elicited by bottom-up stimulation. Here, we used fMRI at high field (7 T) to empirically test this hypothesis, by probing the cortical response to illusory figures in human V1 at different cortical depths [7-14]. We found that, whereas bottom-up stimulation activated all cortical layers, feedback activity induced by illusory figures led to a selective activation of the deep layers of V1. These results demonstrate the potential for non-invasive recordings of neural activity with laminar specificity in humans and elucidate the role of top-down signals during perceptual processing. PMID:26832438

  4. 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

  5. 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

  6. In vitro derivation of germ cells from embryonic stem cells in mammals.

    PubMed

    Zhou, Guang-Bin; Meng, Qing-Gang; Li, Ning

    2010-07-01

    Previous reports have shown that embryonic stem (ES) cells, derived from the inner cell mass of mouse or human blastocysts, could differentiate in vitro into female and male germ cells as well as into the cell types of all three germ layers. While in one case, the ES cell-derived germ cells have been reported to give birth to live offspring in the mouse, these cells differ in fertilization capacity from the sperm and oocytes produced in vivo as they cannot complete meiosis under in vitro conditions. The efficiency of functional germ cell isolation from ES cells is also low. According to published reports, factors such as the proper selection of feeder cells, including ovarian granulosa cells and those which could secrete bone morphogenic protein-4 (BMP4), and the addition of retinoic acid into culture medium, could to some extent establish and improve the microenvironment ES cells rely on for differentiation into germ cells. This review briefly describes the progress of deriving germ cells from ES cells and discusses possible factors that could improve in vitro gamete production. PMID:20575083

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

    PubMed

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

    2013-01-01

    Comparative morphology of the fine structure of fungal hyphal tips often is phylogenetically informative. In particular, morphology of the Spitzenkörper varies among higher taxa. To date no one has thoroughly characterized the hyphal tips of members of the phylum Glomeromycota to compare them with other fungi. This is partly due to difficulty growing and manipulating living hyphae of these obligate symbionts. We observed growing germ tubes of Gigaspora gigantea, G. margarita and G. rosea with a combination of light microscopy (LM) and transmission electron microscopy (TEM). For TEM, we used both traditional chemical fixation and cryo-fixation methods. Germ tubes of all species were extremely sensitive to manipulation. Healthy germ tubes often showed rapid bidirectional cytoplasmic streaming, whereas germ tubes that had been disturbed showed reduced or no cytoplasmic movement. Actively growing germ tubes contain a cluster of 10-20 spherical bodies approximately 3-8 ?m behind the apex. The bodies, which we hypothesize are lipid bodies, move rapidly in healthy germ tubes. These bodies disappear immediately after any cellular perturbation. Cells prepared with cryo-techniques had superior preservation compared to those that had been processed with traditional chemical protocols. For example, cryo-prepared samples displayed two cell-wall layers, at least three vesicle types near the tip and three distinct cytoplasmic zones were noted. We did not detect a Spitzenkörper with either LM or TEM techniques and the tip organization of Gigaspora germ tubes appeared to be similar to hyphae in zygomycetous fungi. This observation was supported by a phylogenetic analysis of microscopic characters of hyphal tips from members of five fungal phyla. Our work emphasizes the sensitive nature of cellular organization, and the need for as little manipulation as possible to observe germ tube structure accurately. PMID:23921242

  8. Cyst and germ tube wall structure in Aphanomyces astaci, Oomycetes.

    PubMed

    Nyhlén, L; Unestam, T

    1978-11-01

    Aphanomyces astaci secondary cyst walls and walls of germinating spores were prepared by alkaline hydrolysis, autolysis, sonication, and enzymic degradation and were examined by shadow-casting and negative-staining techniques. The cyst wall consists of randomly oriented fibrils, about 3 nm in diameter. The fibrils are embedded in, or covered by, amorphous beta-1,3-glucans which can easily be removed by alkaline hydrolysis. The germ tube wall surface has the same structure, but the amorphous layer is less easily removed. PMID:743640

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

    PubMed

    Fulton, Janet E

    2014-02-01

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

  10. Regulation of germ cell function by SUMOylation.

    PubMed

    Rodriguez, Amanda; Pangas, Stephanie A

    2016-01-01

    Oogenesis and spermatogenesis are tightly regulated complex processes that are critical for fertility. Germ cells undergo meiosis to generate haploid cells necessary for reproduction. Errors in meiosis, including the generation of chromosomal abnormalities, can result in reproductive defects and infertility. Meiotic proteins are regulated by post-translational modifications including SUMOylation, the covalent attachment of small ubiquitin-like modifier (SUMO) proteins. Here, we review the role of SUMO proteins in controlling germ cell development and maturation based on recent findings from mouse models. Several studies have characterized the localization of SUMO proteins in male and female germ cells. However, a deeper understanding of how SUMOylation regulates proteins with essential roles in oogenesis and spermatogenesis will provide useful insight into the underlying mechanisms of germ cell development and fertility. PMID:26374733

  11. Why Should I Care about Germs?

    MedlinePLUS

    ... and other fluids under a microscope or do cultures to figure out which germs (if any) are ... nose or coughing, after touching any pets or animals, after gardening, or before and after visiting a ...

  12. Specifying and protecting germ cell fate.

    PubMed

    Strome, Susan; Updike, Dustin

    2015-07-01

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

  13. Imperfect hybrid layers created by an aggressive one-step self-etch adhesive in primary dentin are amendable to biomimetic remineralization in vitro

    PubMed Central

    Kim, Jongryul; Vaughn, Ryan M.; Gu, Lisha; Rockman, Roy A.; Arola, Dwayne D.; Schafer, Tara E.; Choi, Kyungkyu; Pashley, David H.; Tay, Franklin R.

    2009-01-01

    Degradation of hybrid layers created in primary dentin occurs as early as 6 months in vivo. Biomimetic remineralization utilizes “bottom-up” nanotechnology principles for interfibrillar and intrafibrillar remineralization of collagen matrices. This study examined whether imperfect hybrid layers created in primary dentin can be remineralized. Coronal dentin surfaces were prepared from extracted primary molars and bonded using Adper Prompt L-Pop and a composite. One millimeter-thick specimen slabs of the resin-dentin interface were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs to mimic the sequestration and templating functions of dentin noncollagenous proteins. Specimens were retrieved after 1–6 months. Confocal laser scanning microscopy was employed for evaluating the permeability of hybrid layers to Rhodamine B. Transmission electron microscopy was used to examine the status of remineralization within hybrid layers. Remineralization at different locations of the hybrid layers corresponded with quenching of fluorescence within similar locations of those hybrid layers. Remineralization was predominantly intrafibrillar in nature as interfibrillar spaces were filled with adhesive resin. Biomimetic remineralization of imperfect hybrid layers in primary human dentin is a potential means for preserving bond integrity. The success of the current proof-of-concept, laterally-diffusing remineralization protocol warrants development of a clinically-applicable biomimetic remineralization delivery system. PMID:19768792

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

    PubMed Central

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

    2016-01-01

    Abstract This study investigated left ventricular (LV) systolic dysfunction associated with differential strain among myocardial layers in primary hypertension (PH) patients with or without LV hypertrophy (LVH), and normal patients. In 63 PH and 42 healthy patients, two-dimensional speckle tracking echocardiography was used to measure the peak systolic longitudinal and circumferential strain of the myocardial subendocardial, middle and subepicardial layers, and the peak systolic radial strain. To assess LV systolic function, the apical long axis, 4- and 2-chamber views, and parasternal short axis at the basal, middle, and apical levels were acquired by cardiovascular ultrasound (Vivid E9, GE Healthcare, USA). Overall, the pattern in peak systolic longitudinal strain among myocardial layers was subendocardial > middle > subepicardial. In the peak systolic circumferential strain, this was middle > subepicardial > subendocardial. The peak systolic longitudinal strain was normal > NLVH > LVH. Among the groups, the peak systolic circumferential strain at the basal parasternal short-axis level was statistically similar, but at the middle and the apical parasternal short-axis levels were NLVH > normal > LVH. In normal and NLVH patients, the peak radial strain was middle > apical > basal, and in LVH patients was apical > middle > basal. The peak averages of the longitudinal and subendocardial circumferential strains differed significantly when LVH compared with NLVH and normal patients. The systolic function of PH patients was damaged in comparison with normal individuals, which could be detected conveniently and accurately using two-dimensional speckle tracking echocardiography. PMID:26765428

  15. Primary hydatid cyst of the supraspinatus muscle: complete removal of the germinal layer and cytodiagnosis by fine-needle aspiration.

    PubMed

    Das, Dilip K; El-Sharawy, Maha; Ayyash, Emad H; Al-Enezi, Nadia A; Iqbal, Jamshed R; Madda, John P

    2014-03-01

    Primary hydatid disease of the skeletal muscle without systemic involvement is rare. The purpose of this report is to document the novel clinical presentation and the interesting facets of fine-needle aspiration in a case of hydatid disease. It was a case of primary hydatid cyst of the left supraspinatus muscle in an Indian woman living in Kuwait, which was clinically diagnosed as a lipoma. Fine-needle aspiration (FNA) yielded 2 ml of clear fluid with white particulate material. The cytocentrifuged smears prepared from the aspirated fluid showed many scolices, occasional laminated cyst wall fragments and numerous hooklets. The laminated cyst wall and scolices were PAS positive. Trichrome staining imparted a demon-head-like appearance to the scolices. The cytodiagnosis of hydatid cyst was corroborated by histopathological examination of an excised whitish membrane and an irregular cystic fragment, which showed parallel laminations without germinal layer, and skeletal muscle with granulomas and a dense eosinophilic infiltration, respectively. Quantitative serological (indirect hemagglutination) test on blood sample collected 9 days after the excision of the cyst showed insignificant antibody titer to Echinococcus sp. and after 6 weeks the antibodies were completely absent. CT scan of the chest and abdomen performed 7 weeks after removal of cyst showed no evidence of visceral hydatid cyst. PMID:23008130

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

    ClinicalTrials.gov

    2015-03-04

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

  17. 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

  18. Germ-cell sensitivity in mammals

    SciTech Connect

    Adler, I.D.

    1982-01-01

    The differences in mammalian germ-cell sensitivity have been studied with a number of mutagenic agents using both chromosomal aberrations and point mutations as genetic endpoints. I have tried to give a survey on the present knowledge. Several conclusions can be drawn at present: 1. In spermatogenesis the sensitivity to mutation induction differs between various post-spermatogonial stages and spermatogonia. 2. Heritable structural chromosomal changes are primarily recovered from post-spermatogonial germ cells. The sensitivity pattern is similar in dominant lethal and heritable translocation experiments. The effect recovered from spermatogonia is near zero. 3. Structurally related chemicals show a difference in their spermatogenic response. The most obvious example gave the induction of specific locus mutations by ENU and MNU. 4. Since too little information is available it seems prudent to assume that oocytes and spermatogonia may show similar sensitivity so that in risk estimates effects on female germ cells cannot be neglected. The final result from the previous discussion must be that the limitations of knowledge are obvious, they lie in the limited number of chemicals tested in mammalian germ-cell assays. A larger data base of mammalian germ-cell response to chemical mutagens is urgently needed.

  19. Immortalization of Mouse Germ Line Stem Cells

    PubMed Central

    Hofmann, Marie-Claude; Braydich-Stolle, Laura; Dettin, Luis; Johnson, Eric; Dym, Martin

    2011-01-01

    In the mammalian testis, the germ line stem cells are a small subpopulation of type A spermatogonia that proliferate and ultimately differentiate into sperm under the control of both endocrine and paracrine factors. To study the early phases of spermatogenesis at the molecular level, an in vitro system must be devised whereby germ line stem cells can be either cultured for a prolonged period of time or expanded as cell lines. In the study reported here, we chose to immortalize type A spermatogonia using the Simian virus large T-antigen gene (LTAg) under the control of an ecdysone-inducible promoter. While the cells escaped the hormonal control after a finite number of generations and expressed the LTAg constitutively, their growth remained slow and the cells exhibited morphological features typical of spermatogonia at the light microscopic level. Moreover, the cells expressed detectable levels of protein markers specific for germ cells such as Dazl, and specific for germ line stem cells such as Oct-4, a transcription factor, and GFR?-1, the receptor for glial cell line–derived neurotrophic factor (GDNF). Further analysis confirmed the spermatogonial phenotype and also revealed the expression of markers expressed in stem cells such as Piwi12 and Prame11. Since the cells respond to GDNF by a marked increase in their rate of proliferation, this cell line represents a good in vitro model for studying aspects of mouse germ line stem cell biology. PMID:15671143

  20. Sex determination in the germ line.

    PubMed Central

    Ellis, Ronald; Schedl, Tim

    2007-01-01

    Sexual identity is one of a few basic parameters that specify how development should proceed. Although sex determination has profound effects on many tissues, its most ancient and fundamental role is ensuring that some germ cells become sperm, and others become oocytes or eggs. Spermatocytes and oocytes are usually produced in male and female animals, respectively, but C. elegans is uniquely suitable for studying the control of these cell fates because both types of cells are made from a common pool of progenitors in XX hermaphrodites. Extensive genetic and molecular studies have shown that the sexual fate of germ cells in C. elegans is controlled by the same genes that regulate sexual identity in other parts of the animal. However, this regulatory pathway has additional features that are unique to the germ line. First, several genes, like the three fogs, act only in germ cells. Second, the three fem genes act in concert with targets of tra-1 to control germ cell fates, but do not act this way in the soma. Third, translational repression of tra-2 is essential for hermaphrodite spermatogenesis. Fourth, translational repression of fem-3 is needed for oogenesis. In this review, we present genetic and molecular models for how these processes work, and summarize the evidence upon which they are built. PMID:18050498

  1. 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

  2. Acute limb ischemia due to malignant arterial embolism from a metastatic germ cell tumor.

    PubMed

    Stein, M E; Drumea, K; Ben-Itshak, O; Hoffman, A; Eyal, A; Moshkovitz, B; Haim, N

    1995-08-01

    Arterial tumor embolization is a rare but serious complication of neoplastic disease. The majority of these tumors are associated with primary or secondary lung malignancies, originating from pulmonary vein metastasis or from an atrial mass. Malignant germ cell tumors primarily disseminate to the retroperitoneal lymph nodes and lung, and to the brain and liver later in the course of the disease. A germ cell tumor metastasis embolizing to the iliac-femoral arterial system has not yet been reported. We report a metastatic embolism in a patient with disseminated embryonal cell carcinoma causing acute limb ischemia, managed by surgical embolectomy. The sudden development of limb ischemia in a patient with a germ cell tumor should alert the physician to the possibility of tumor embolism. PMID:7603399

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

    PubMed Central

    Kirk, Robert G. W.

    2012-01-01

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

  4. Direct Reprogramming of Human Primordial Germ Cells into Induced Pluripotent Stem Cells: Efficient Generation of Genetically Engineered Germ Cells.

    PubMed

    Bazley, Faith A; Liu, Cyndi F; Yuan, Xuan; Hao, Haiping; All, Angelo H; De Los Angeles, Alejandro; Zambidis, Elias T; Gearhart, John D; Kerr, Candace L

    2015-11-15

    Primordial germ cells (PGCs) share many properties with embryonic stem cells (ESCs) and innately express several key pluripotency-controlling factors, including OCT4, NANOG, and LIN28. Therefore, PGCs may provide a simple and efficient model for studying somatic cell reprogramming to induced pluripotent stem cells (iPSCs), especially in determining the regulatory mechanisms that fundamentally define pluripotency. Here, we report a novel model of PGC reprogramming to generate iPSCs via transfection with SOX2 and OCT4 using integrative lentiviral. We also show the feasibility of using nonintegrative approaches for generating iPSC from PGCs using only these two factors. We show that human PGCs express endogenous levels of KLF4 and C-MYC protein at levels similar to embryonic germ cells (EGCs) but lower levels of SOX2 and OCT4. Transfection with both SOX2 and OCT4 together was required to induce PGCs to a pluripotent state at an efficiency of 1.71%, and the further addition of C-MYC increased the efficiency to 2.33%. Immunohistochemical analyses of the SO-derived PGC-iPSCs revealed that these cells were more similar to ESCs than EGCs regarding both colony morphology and molecular characterization. Although leukemia inhibitory factor (LIF) was not required for the generation of PGC-iPSCs like EGCs, the presence of LIF combined with ectopic exposure to C-MYC yielded higher efficiencies. Additionally, the SO-derived PGC-iPSCs exhibited differentiation into representative cell types from all three germ layers in vitro and successfully formed teratomas in vivo. Several lines were generated that were karyotypically stable for up to 24 subcultures. Their derivation efficiency and survival in culture significantly supersedes that of EGCs, demonstrating their utility as a powerful model for studying factors regulating pluripotency in future studies. PMID:26154167

  5. 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.

  6. Germ cell sex determination: piecing together a complex puzzle.

    PubMed

    Wawersik, Matthew

    2006-07-01

    In many multicellular organisms, proper germ cell development is crucial for production of future generations. One critical step in this process is the decision of germ cells to develop into either sperm or eggs. Defects in germ cell sex determination can lead to infertility and germ cell tumors. However, while much is known about somatic sex determination, regulation of germ cell sex is not well understood. Recent studies with Drosophila reveal that the janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway promotes male germ cell development during early stages of gonad morphogenesis.(1) Here, this and other work suggesting that the JAK/STAT pathway acts alongside a host of other factors to regulate germ cell sex determination is discussed. Furthermore, recent insights into mouse germ cell sex determination are reviewed; revealing a number of correlations that suggest similar mechanisms may regulate aspects of both mouse and Drosophila germline sexual dimorphism. PMID:16855383

  7. 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.

  8. Evaluation of corn germ meal as extender in plywood adhesive

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the potential of corn germ meal as protein extender in plywood adhesive. Partially defatted dried corn germ, containing 2.1% (dry basis, db) crude oil and 24.7% (db) crude protein, was ground to 40-mesh particle size. The corn germ meal was then substituted (on...

  9. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. 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,…

  12. UTILIZING CORN GERM MEAL IN PLYWOOD GLUE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the potential of corn germ meal as protein extender in plywood adhesive. This research is part of our laboratory’s efforts to develop new uses for the proteinaceous co-products from cereal and soybean processing. We were previously successful in formulating a s...

  13. 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,…

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

    ERIC Educational Resources Information Center

    Scheer, Judith K.

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

  15. 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

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

    PubMed Central

    Murphy, Caitlin J; Richburg, John H

    2014-01-01

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

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

    PubMed

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

    2015-10-15

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-03-01

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

  20. 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...

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

    SciTech Connect

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

    1995-03-01

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

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

    PubMed Central

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

    2014-01-01

    The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year resulting in a single spermiation event with sperm stored within the epididymis until the next spring mating season. PMID:26413408

  3. 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

  4. The biology of the germ line in echinoderms.

    PubMed

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

    2014-08-01

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

  5. State of the art in germ cell tumor imaging.

    PubMed

    Secil, Mustafa; Altay, Canan; Basara, Isil

    2016-03-01

    Germ cell tumors (GCTs) are the most common tumors of the testis and arise from germinal epithelium cells in the seminiferous tubules. All GCTs show malignant behavior and frequently metastasize. The diagnosis of GCTs depends on the clinical manifestations, laboratory parameters, preoperative imaging features, and tissue biomarkers. Ultrasonography and Doppler ultrasonography are the primary imaging modalities used to evaluate testicular masses. Sonoelastography is a diagnostic tool that can measure the stiffness of tissue and may differentiate between benign and malignant tumors of testis. Magnetic resonance imaging of the scrotum may be used as an additional tool, which may provide additional information owing to its high soft tissue contrast discrimination capability. Computed tomography of the thorax and abdomen and positron emission tomography/computed tomography are used for staging of the disease and for follow-up after treatment. PMID:26215982

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

    PubMed

    Cwiek-Ludwicka, Kazimiera; Pawlicka, Marzena; Starski, Andrzej; Pó?torak, Hanna; Kar?owski, Kazimierz

    2011-01-01

    The aim of this study was to identify of primary aromatic amines (PAAs) and to determine their migration from plastic food packaging. The magnitude of the migration of these substances from plastic food packaging consists a base for the evaluation of their compliance with the requirements of EU legislation and hazard for human health taking into account their migration into food. The unprinted and printed multi-layer plastic packaging (laminates), domestic and imported, were examined in these studies. PAAs migration tests from the laminates into food simulant (3% acetic acid) was performed according to the appropriate procedures recommended in the EU for testing migration from food contact articles under standard conditions reflecting the real use of laminates (10 days, 40 degrees C) and under ,, worst case scenario" conditions (2 h, 70 degrees C). PAAs present in migration solutions were concentrated on SPE columns and then seven PAAs (aniline, 1,3-phenylenediamine, 2, 6-toluenediamine, 2,4-toluenediamine, 4,4'-oxydianiline, 4,4'-methylenedianiline and 3,3 '-dimethylbenzidyne) were identified and determined by previously validated HPLC-DAD method. Depending on the migration conditions the PAAs content was different. When the "worst case scenario" conditions were applied the migration of 4,4 '-methylenedianiline (4,4 '-MDA) ranged from below detection limit (LOD = 0.51 microg/kg) up to 9.86 microg/kg, and aniline was released in the range from below detection limit (LOD = 0,98 microg/kg) up to 7.04 microg/kg. In two laminate samples of eight examined, the sum of PAAs (aniline and 4,4'-MDA) was 13.32 microg/kg and 14.72 microg/kg showing that the permitted limit (10 microg/kg) was exceeded. In the standard conditions, the migration of aniline and 4,4'-MDA was significantly lower Regarding the carcinogenic potential of PAAs, the laminates causing the amines migration above the permitted limit should not be used as food packaging. PMID:22435290

  7. Compartmentalization and regulation of iron metabolism proteins protect male germ cells from iron overload.

    PubMed

    Leichtmann-Bardoogo, Yael; Cohen, Lyora A; Weiss, Avital; Marohn, Britta; Schubert, Stephanie; Meinhardt, Andreas; Meyron-Holtz, Esther G

    2012-06-15

    The universal importance of iron, its high toxicity, and complex chemistry present a challenge to biological systems in general and to protected compartments in particular. The high mitotic rate and avid mitochondriogenesis of developing male germ cells imply high iron requirements. Yet access to germ cells is tightly regulated by the blood-testis barrier that protects the meiotic and postmeiotic germ cells. To elucidate how iron is supplied to developing male germ cells, we analyzed iron deposition and iron transport proteins in testes of mice with iron overload and with genetic ablation of the iron regulators Hfe and iron regulatory protein 2. Iron accumulated mainly around seminiferous tubules, and only small amounts localized within the seminiferous tubules. The localization and regulation of proteins involved in iron import, storage, and export such as transferrin, transferrin receptor, the divalent metal transporter-1, cytosolic ferritin, and ferroportin strongly support a model of a largely autonomous iron cycle within seminiferous tubules. We show evidence that ferritin secretion from Sertoli cells may play an important role in iron acquisition of primary spermatocytes. During spermatogenic development iron is carried along from primary spermatocytes to spermatids, and from spermatids iron is recycled to the apical compartment of Sertoli cells, which traffic it back to a new generation of spermatocytes. Losses are replenished by the peripheral circulation. Such an internal iron cycle essentially detaches the iron homeostasis within the seminiferous tubule from the periphery and protects developing germ cells from iron fluctuations. This model explains how compartmentalization can optimize cellular and systemic nutrient homeostasis. PMID:22496346

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

    PubMed

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

    2015-07-01

    Germ cell cluster organization and the process of oogenesis in Dactylobiotus parthenogeneticus have been described using transmission electron microscopy and light microscopy. The reproductive system of D. parthenogeneticus is composed of a single, sac-like, meroistic ovary and a single oviduct that opens into the cloaca. Two zones can be distinguished in the ovary: a small germarium that is filled with oogonia and a vitellarium that is filled with germ cell clusters. The germ cell cluster, which has the form of a modified rosette, consists of eight cells that are interconnected by stable cytoplasmic bridges. The cell that has the highest number of stable cytoplasmic bridges (four bridges) finally develops into the oocyte, while the remaining cells become trophocytes. Vitellogenesis of a mixed type occurs in D. parthenogeneticus. One part of the yolk material is produced inside the oocyte (autosynthesis), while the second part is synthesized in the trophocytes and transported to the oocyte through the cytoplasmic bridges. The eggs are covered with two envelopes: a thin vitelline envelope and a three-layered chorion. The surface of the chorion forms small conical processes, the shape of which is characteristic for the species that was examined. In our paper, we present the first report on the rosette type of germ cell clusters in Parachela. PMID:25433446

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

    PubMed

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

    2005-03-15

    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 the sex differentiation in zebrafish. To this end, we ablated the germ cells using two independent methods and followed the development of the experimental fish. First, PGCs were ablated by knocking down the function of dead end, a gene important for the survival of this lineage. Second, a method to eliminate the PGCs using the toxin-antitoxin components of the parD bacterial genetic system was used. Specifically, we expressed a bacterial toxin Kid preferentially in the PGCs and at the same time protected somatic cells by uniformly expressing the specific antidote Kis. Our results demonstrate an unexpected role for the germ line in promoting female development because PGC-ablated fish invariably developed as males. PMID:15728735

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    ClinicalTrials.gov

    2015-04-08

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

  13. On the development of extragonadal and gonadal human germ cells.

    PubMed

    Heeren, A Marijne; He, Nannan; de Souza, Aline F; Goercharn-Ramlal, Angelique; van Iperen, Liesbeth; Roost, Matthias S; Gomes Fernandes, Maria M; van der Westerlaken, Lucette A J; Chuva de Sousa Lopes, Susana M

    2016-01-01

    Human germ cells originate in an extragonadal location and have to migrate to colonize the gonadal primordia at around seven weeks of gestation (W7, or five weeks post conception). Many germ cells are lost along the way and should enter apoptosis, but some escape and can give rise to extragonadal germ cell tumors. Due to the common somatic origin of gonads and adrenal cortex, we investigated whether ectopic germ cells were present in the human adrenals. Germ cells expressing DDX4 and/or POU5F1 were present in male and female human adrenals in the first and second trimester. However, in contrast to what has been described in mice, where 'adrenal' and 'ovarian' germ cells seem to enter meiosis in synchrony, we were unable to observe meiotic entry in human 'adrenal' germ cells until W22. By contrast, 'ovarian' germ cells at W22 showed a pronounced asynchronous meiotic entry. Interestingly, we observed that immature POU5F1+ germ cells in both first and second trimester ovaries still expressed the neural crest marker TUBB3, reminiscent of their migratory phase. Our findings highlight species-specific differences in early gametogenesis between mice and humans. We report the presence of a population of ectopic germ cells in the human adrenals during development. PMID:26834021

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

    PubMed Central

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

    2015-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. 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. PMID:26064916

  17. A process for the aqueous enzymatic extraction of corn oil from dry-milled corn germ and enzymatic wet milled corn germ (E-Germ)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we reported an aqueous enzymatic oil extraction process that achieved oil yields of 80-90% using corn germ from a commercial corn wet mill. Three commercial cellulases were reported to result in similar oil yields when wet milles corn germ was used as a feedstock in this process. When ...

  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

    2015-12-08

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    ClinicalTrials.gov

    2015-05-01

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

  2. Germ tube-specific antigens of Candida albicans cell walls

    SciTech Connect

    Sundstrom, P.R.

    1986-01-01

    Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specific antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with /sup 125/I, or metabolically with (/sup 35/S) methionine or (/sup 3/H) mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen.

  3. Liver sinusoid on a chip: Long-term layered co-culture of primary rat hepatocytes and endothelial cells in microfluidic platforms.

    PubMed

    Kang, Young Bok Abraham; Sodunke, Temitope R; Lamontagne, Jason; Cirillo, Joseph; Rajiv, Caroline; Bouchard, Michael J; Noh, Moses

    2015-12-01

    We describe the generation of microfluidic platforms for the co-culture of primary hepatocytes and endothelial cells; these platforms mimic the architecture of a liver sinusoid. This paper describes a progressional study of creating such a liver sinusoid on a chip system. Primary rat hepatocytes (PRHs) were co-cultured with primary or established endothelial cells in layers in single and dual microchannel configurations with or without continuous perfusion. Cell viability and maintenance of hepatocyte functions were monitored and compared for diverse experimental conditions. When primary rat hepatocytes were co-cultured with immortalized bovine aortic endothelial cells (BAECs) in a dual microchannel with continuous perfusion, hepatocytes maintained their normal morphology and continued to produce urea for at least 30 days. In order to demonstrate the utility of our microfluidic liver sinusoid platform, we also performed an analysis of viral replication for the hepatotropic hepatitis B virus (HBV). HBV replication, as measured by the presence of cell-secreted HBV DNA, was successfully detected. We believe that our liver model closely mimics the in vivo liver sinusoid and supports long-term primary liver cell culture. This liver model could be extended to diverse liver biology studies and liver-related disease research such as drug induced liver toxicology, cancer research, and analysis of pathological effects and replication strategies of various hepatotropic infectious agents. . PMID:25994312

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

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee; Cucinotta, Francis A.

    2010-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  6. The fascinating germ theories on cancer pathogenesis.

    PubMed

    Tsoucalas, G; Laios, K; Karamanou, M; Gennimata, V; Androutsos, G

    2014-01-01

    For more than 100 years, the germ theory of cancer, proposing that microorganisms were at the origin of the disease, dominated medicine. Several eminent scientists like Etienne Burnet, Mikhail Stepanovich Voronin, Charles-Louis Malassez, and Francis-Peyton Rous argued on the pathogenesis presenting their theories that implicated cocci, fungi and parasites. The impact of these theories was culminated by the Nobel Prize in 1926 that was attributed to the Danish scientist Johannes Fibiger for his work on the nematode Spiroptera as a causative agent in cancer. Even if those theories were the result of fantasy and misinterpretation, they paved the way for the scientific research in oncology. PMID:24659685

  7. Gene manipulation: churches against germ changes.

    PubMed

    Budiansky, S

    An immediate ban on human genetic engineering that alters germ cells is called for in a resolution, written by activist Jeremy Rifkin, that was released last week over the signatures of 21 Catholic bishops, a broad spectrum of Protestant and Jewish religious leaders, and three scientists. The resolution takes a much harder line than was espoused by religious leaders in a letter to the now-defunct President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. Several of the signers indicated that they did not fully agree with the resolution, but saw it as a good vehicle to encourage public discussion. PMID:6574323

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

    SciTech Connect

    Teng, Yincheng; Chen, Bin; Tao, Minfang

    2009-12-18

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

  9. Mechanisms controlling primary and new production in a global ecosystem model Part I: The role of the large-scale upper mixed layer variability

    NASA Astrophysics Data System (ADS)

    Popova, E. E.; Coward, A. C.; Nurser, G. A.; de Cuevas, B.; Fasham, M. J. R.; Anderson, T. R.

    2006-07-01

    A global general circulation model coupled to a simple six-compartment ecosystem model is used to study the extent to which global variability in primary and export production can be realistically predicted on the basis of advanced parameterizations of upper mixed layer physics, without recourse to introducing extra complexity in model biology. The ''K profile parameterization'' (KPP) scheme employed, combined with 6-hourly external forcing, is able to capture short-term periodic and episodic events such as diurnal cycling and storm-induced deepening. The model realistically reproduces various features of global ecosystem dynamics that have been problematic in previous global modelling studies, using a single generic parameter set. The realistic simulation of deep convection in the North Atlantic, and lack of it in the North Pacific and Southern Oceans, leads to good predictions of chlorophyll and primary production in these contrasting areas. Realistic levels of primary production are predicted in the oligotrophic gyres due to high frequency external forcing of the upper mixed layer (accompanying paper Popova et al., 2006) and novel parameterizations of zooplankton excretion. Good agreement is shown between model and observations at various JFOFS time series sites: BATS, KERFIX, Papa and station India. One exception is that the high zooplankton grazing rates required to maintain low chlorophyll in high-nutrient low-chlorophyll and oligotrophic systems lessened agreement between model and data in the northern North Atlantic, where mesozooplankton with lower grazing rates may be dominant. The model is therefore not globally robust in the sense that additional parameterizations were needed to realistically simulate ecosystem dynamics in the North Atlantic. Nevertheless, the work emphasises the need to pay particular attention to the parameterization of mixed layer physics in global ocean ecosystem modelling as a prerequisite to increasing the complexity of ecosystem models.

  10. Fluxes of carbon and nutrients to the Iceland Sea surface layer and inferred primary productivity and stoichiometry

    NASA Astrophysics Data System (ADS)

    Jeansson, E.; Bellerby, R. G. J.; Skjelvan, I.; Frigstad, H.; Ólafsdóttir, S. R.; Olafsson, J.

    2015-02-01

    This study evaluates long-term mean fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea. The study utilises hydro-chemical data from the Iceland Sea time series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), and a sub-surface layer (100-200 m), we calculate monthly deficits in the surface, and use these to deduce the long-term mean surface layer fluxes that affect the deficits: vertical mixing, horizontal advection, air-sea exchange, and biological activity. The deficits show a clear seasonality with a minimum in winter, when the mixed layer is at the deepest, and a maximum in early autumn, when biological uptake has removed much of the nutrients. The annual vertical fluxes of DIC and nitrate amounts to 2.9 ± 0.5 and 0.45 ± 0.09 mol m-2 yr-1, respectively, and the annual air-sea uptake of atmospheric CO2 is 4.4 ± 1.1 mol C m-2 yr-1. The biologically driven changes in DIC during the year relates to net community production (NCP), and the net annual NCP corresponds to export production, and is here calculated as 7.3 ± 1.0 mol C m-2 yr-1. The typical, median C : N ratio during the period of net community uptake is 9.0, and clearly higher than the Redfield ratio, but is varying during the season.

  11. Molecular genetics of testicular germ cell tumors

    PubMed Central

    Sheikine, Yuri; Genega, Elizabeth; Melamed, Jonathan; Lee, Peng; Reuter, Victor E.; Ye, Huihui

    2012-01-01

    Testicular germ cell tumors (TGCT) are the most common malignancy in young men. While most TGCT are potentially curable, approximately 5% of patients with TGCT may develop chemoresistance and die from the disease. This review article summarizes current knowledge in genetics underlying the development, progression and chemoresistance of TGCT. Most post-pubertal TGCT originate from intratubular germ cell neoplasia unclassified (IGCNU), which are transformed fetal gonocytes. Development of IGCNU may involve aberrantly activated KITLG/KIT pathway and overexpression of embryonic transcription factors such as NANOG and POU5F1, which leads to suppression of apoptosis, increased proliferation, and accumulation of mutations in gonocytes. Invasive TGCT consistently show gain of chromosome 12p, typically isochromosome 12p. Single gene mutations are uncommon in TGCT. KIT, TP53, KRAS/NRAS, and BRAF are genes most commonly mutated in TGCT and implicated in their pathogenesis. Different histologic subtypes of TGCT possess different gene expression profiles that reflect different directions of differentiation. Their distinct gene expression profiles are likely caused by epigenetic regulation, in particular DNA methylation, but not by gene copy number alterations. Resistance of TGCT to chemotherapy has been linked to karyotypic aberrations, single-gene mutations, and epigenetic regulation of gene expression in small-scale studies. The study of TGCT genetics could ultimately translate into development of new molecular diagnostic and therapeutic modalities for these tumors and improve the care of patients with these malignancies. PMID:22432056

  12. August Weismann on germ-plasm variation.

    PubMed

    Winther, R G

    2001-01-01

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

  13. Pediatric germ cell tumors presenting beyond childhood?

    PubMed

    Oosterhuis, J W; Stoop, J A; Rijlaarsdam, M A; Biermann, K; Smit, V T H B M; Hersmus, R; Looijenga, L H J

    2015-01-01

    Four cases are reported meeting the criteria of a pediatric (i.e., Type I) testicular germ cell tumor (TGCT), apart from the age of presentation, which is beyond childhood. The tumors encompass the full spectrum of histologies of pediatric TGCT: teratoma, yolk sac tumor, and various combinations of the two, and lack intratubular germ cell neoplasia/carcinoma in situ in the adjacent parenchyma. The neoplasms are (near)diploid, and lack gain of 12p, typical for seminomas and non-seminomas of the testis of adolescents and adults (i.e., Type II). It is proposed that these neoplasms are therefore late appearing pediatric (Type I) TGCT. The present report broadens the concept of earlier reported benign teratomas of the post-pubertal testis to the full spectrum of pediatric TGCT. The possible wide age range of pediatric TGCT, demonstrated in this study, lends credence to the concept that TGCT should according to their pathogenesis be classified into the previously proposed types. This classification is clinically relevant, because Type I mature teratomas are benign tumors, which are candidates for testis conserving surgery, as opposed to Type II mature teratomas, which have to be treated as Type II (malignant) non-seminomas. PMID:25427839

  14. Intracranial germ cell tumours: I. Experience with platinum based chemotherapy and implications for curative chemoradiotherapy.

    PubMed

    Sebag-Montefiore, D J; Douek, E; Kingston, J E; Plowman, P N

    1992-11-01

    The results of treatment with platinum based combination chemotherapy in ten patients with intracranial germ cell tumours (GCT) are presented. Two patients, treated for relapse within the central nervous system (CNS), attained partial responses of short duration. One patient with systemic relapse was successfully salvaged with chemotherapy. Seven patients received primary chemotherapy, six of whom received a 'CNS friendly' regimen consisting of vincristine, etoposide, carboplatin (VEJ) prior to craniospinal axis (CSA) irradiation. Three complete and three partial responses, and one patient with stable disease, were seen prior to irradiation. All seven patients are alive and remain disease-free at a median time of 12 months after treatment. Current treatment policy for germinomas attaining complete response to two courses of VEJ is a lowered CSA dose prescription, while non-germinomatous germ cell tumours (NGGCT) receive standard total dose CSA irradiation. PMID:1281421

  15. Quantitative activity-induced manganese-dependent MRI for characterizing cortical layers in the primary somatosensory cortex of the rat.

    PubMed

    Auffret, Matthieu; Samim, Idrees; Lepore, Mario; Gruetter, Rolf; Just, Nathalie

    2016-03-01

    The ability of Mn(2+) to follow Ca(2+) pathways upon stimulation transform them into remarkable surrogate markers of neuronal activity using activity-induced manganese-dependent MRI (AIM-MRI). In the present study, a precise follow-up of physiological parameters during MnCl2 and mannitol infusions improved the reproducibility of AIM-MRI allowing in-depth evaluation of the technique. Pixel-by-pixel T1 data were investigated using histogram distributions in the barrel cortex (BC) and the thalamus before and after Mn(2+) infusion, after blood brain barrier opening and after BC activation. Mean BC T1 values dropped significantly upon trigeminal nerve (TGN) stimulation (-38 %, P = 0.02) in accordance with previous literature findings. T1 histogram distributions showed that 34 % of T1s in the range 600-1500 ms after Mn(2+ )+ mannitol infusions shifted to 50-350 ms after TGN stimulation corresponding to a twofold increase of the percentage of pixels with the lowest T1s in BC. Moreover, T1 changes in response to stimulation increased significantly from superficial cortical layers (I-III) to deeper layers (V-VI). Cortical cytoarchitecture detection during a functional paradigm was performed extending the potential of AIM-MRI. Quantitative AIM-MRI could thus offer a means to interpret local neural activity across cortical layers while identification of the role of calcium dynamics in vivo during brain activation could play a key role in resolving neurovascular coupling mechanisms. PMID:25366973

  16. Evolution of a Two-Layer Oxide Coating on the Steel Surface of the Primary Coolant Circuit in the Course of Nuclear Power Plant Operation

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Orlova, E. A.; Kozlov, F. A.; Varseev, E. V.

    2016-01-01

    An analysis of the laws governing mass transfer in a uniform oxide coating on the surface of a circuit is presented. As a result of calculations, the distribution of the fluxes of magnetite and of the particles of corrosion product suspensions depositing on the surface of the throughput section, as well as the distribution of the fluxes of dissolved iron, emerging from steel, along the length of the hydraulic system of the primary coolant circuit of the BREST-type plant, have been refined. The laws governing the process of mass transfer in the BREST-type primary coolant circuit with account for the oxide coating thickness variable in time have been obtained. The distribution of the thicknesses of the magnetite and spinel layers on the steel surface along the length of the BREST-type circulation loop after 365 days from the start of operation in a nominal regime is shown.

  17. GERM CELL DEVELOPMENT IN MEISHAN AND WHITE COMPOSITE GILTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Maxim...

  18. 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

  19. Genes associated with the development of the male germ line.

    PubMed

    Readhead, Carol; Müller-Tidow, Carsten

    2002-01-01

    The development of the mammalian germ line has been well studied, from the designation of primordial germ cells and their migration in the embryo to their progression through gametogenesis. The pattern of germ cell development, as established through classical studies, is now being overlaid with molecular, genetic and epigenetic data. Eventually, proteonomics will lead to a deeper understanding of the function of these genes. Through knowledge of germ cell gene expression patterns, it is now possible to develop transgenic molecular tools for the isolation of germ cells at different stages of development. By linking stage-specific germ cell promoter regions to the green fluorescent protein (GFP) reporter gene it is possible to tag these cells genetically for histological identification and cell sorting. Our long-term goal is to develop male germ cells as stem cells for therapeutic purposes. It is hoped that this goal will be achieved by purifying germ cells at different stages in development and gaining a deeper understanding of them by studying their gene expression patterns, potency and plasticity, both in vivo and in vitro. PMID:12470336

  20. Germ cell transplantation in an azoospermic Klinefelter bull.

    PubMed

    Joerg, Hannes; Janett, Fredi; Schlatt, Stefan; Mueller, Simone; Graphodatskaya, Daria; Suwattana, Duangsmorn; Asai, Mika; Stranzinger, Gerald

    2003-12-01

    Germ cell transplantation is a technique that transfers donor testicular cells into recipient testes. A population of germ cells can colonize the recipient testis, initiate spermatogenesis, and produce sperm capable of fertilization. In the present study, a nonmosaic Klinefelter bull was used as a germ cell recipient. The donor cell suspension was introduced into the rete testis using ultrasound-guided puncture. A pulsatile administration of GnRH was performed to stimulate spermatogenesis. The molecular approach to detect donor cells was done by a quantitative polymerase chain reaction with allele discrimination based on a genetic mutation between donor and recipient. Therefore, a known genetic mutation, associated with coat-color phenotype, was used to calculate the ratio of donor to recipient cells in the biopsy specimens and ejaculates for 10 mo. After slaughtering, meiotic preparations were performed. The injected germ cells did not undergo spermatogenesis. Six months after germ cell transplantation, the donor cells were rejected, which indicates that the donor cells could not incorporate in the testis. The hormone stimulation showed that the testosterone-producing Leydig cells were functionally intact. Despite subfertility therapy, neither the recipient nor the donor cells underwent spermatogenesis. Therefore, nonmosaic Klinefelter bulls are not suitable as germ cell recipients. Future germ cell recipients in cattle could be mosaic Klinefelters, interspecies hybrids, bulls with Sertoli cell-only syndrome, or bulls with disrupted germ cell migration caused by RNA interference. PMID:12930718

  1. 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...

  2. 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

  3. Progress in gene transfer by germ cells in mammals.

    PubMed

    Niu, Yidong; Liang, Shulong

    2008-12-01

    Use of germ cells as vectors for transgenesis in mammals has been well developed and offers exciting prospects for experimental and applied biology, agricultural and medical sciences. Such approach is referred to as either male germ cell mediated gene transfer (MGCMGT) or female germ cell mediated gene transfer (FGCMGT) technique. Sperm-mediated gene transfer (SMGT), including its alternative method, testis-mediated gene transfer (TMGT), becomes an established and reliable method for transgenesis. They have been extensively used for producing transgenic animals. The newly developed approach of FGCMGT, ovary-mediated gene transfer (OMGT) is also a novel and useful tool for efficient transgenesis. This review highlights an overview of the recent progress in germ cell mediated gene transfer techniques, methods developed and mechanisms of nucleic acid uptake by germ cells. PMID:19103425

  4. Spike firing and IPSPs in layer V pyramidal neurons during beta oscillations in rat primary motor cortex (M1) in vitro.

    PubMed

    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

  5. 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

  6. 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

  7. 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

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

    ClinicalTrials.gov

    2015-05-11

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

  9. Intracranial germ cell tumours: II. The application of a partial transmission block technique to reduce late morbidity.

    PubMed

    Sebag-Montefiore, D J; Doughty, D; Plowman, P N

    1992-11-01

    Craniospinal axis (CSA) irradiation may be associated with significant late sequelae. The recognition of the influence of dose per fraction on late sequelae and the radiosensitivity of germ cell tumours (GCT) led to the adoption of a partial transmission block (PTB) technique for patients with intracranial GCTs. The PTB allows a dose differential between the whole cranium (prophylactic area) and the primary site (high-dose area) throughout the CSA prescription. The PTB technique has been used in four patients, two with germinoma and two with non-germinomatous germ cell tumours (NGGCT). All patients received two courses of primary chemotherapy with at least a partial response prior to CSA irradiation with the PTB and a three-field boost to the primary site. There was no prolongation in the overall treatment time. The use of this 'CNS friendly' radiotherapy technique was straightforward and the potential benefit in reducing late sequelae is discussed using two isoeffect methods. PMID:1334425

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

    PubMed Central

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

    2015-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  12. Genetic modification of chicken germ cells

    PubMed Central

    Park, Tae Sub; Han, Jae Yong

    2012-01-01

    Over the past two decades numerous reports have demonstrated that the genetic modification of poultry genomes has great potential for improving poultry production; moreover, it may be used as a powerful tool for the production of industrial proteins. To date, transgenic techniques have been established for generating transgenic birds that express recombinant human proteins in hen eggs, as well as tissue-specific genes as an animal model. The production of transgenic birds is a promising approach that could have practical applications in agriculture and biopharmacology, in addition to advancing our understanding of avian biology. Finally, germ cell–mediated transgenesis could provide a more efficient strategy for creating gene-targeted insertions and deletions in avian species. PMID:23050971

  13. nanos is required for formation of the spectrosome, a germ cell-specific organelle.

    PubMed

    Wawersik, Matthew; Van Doren, Mark

    2005-09-01

    Germ cell identity and development are controlled by autonomous cues in the germ plasm as well as by interactions between germ cells and somatic cells. Here, we investigate the formation of a germ cell-specific organelle, the spectrosome. We find that spectrosome formation is independent of germ cell-soma interactions and is autonomous to the germ cells. Furthermore, the germ plasm component nanos (nos) is essential for spectrosome formation. The role of nos in spectrosome formation is independent of its role in germ cell survival; nos mutant germ cells that are prevented from undergoing programmed cell death still fail to form spectrosomes. Thus, nos is required to regulate the formation of this germ cell-specific organelle, further supporting a role for nos in promoting germ cell identity. PMID:16028275

  14. Methylation changes in porcine primordial germ cells.

    PubMed

    Petkov, Stoyan G; Reh, Wade A; Anderson, Gary B

    2009-01-01

    Epigenetic re-programming is an important event in the development of primordial germ cells (PGC) into functional gametes, characterized by genome-wide erasure of DNA methylation and re-establishment of epigenetic marks, a process essential for restoration of the potential for totipotency. In this study changes in the methylation status of centromeric repeats and two IGF2-H19 differentially methylated domain (DMD) sequences were examined in porcine PGC between Days 24 and 31 of pregnancy. The methylation levels of centromeric repeats and IGF2-H19 DMD sequences decreased rapidly from Days 24 to 28 in both male and female PGC. At Days 30 and 31 of pregnancy centromeric repeats and IGF2-H19 DMD sequences acquired new methylation in male PGC, while in female PGC these sequences were completely demethylated by Day 30 and remained hypomethylated at Day 31. To characterize methylation changes that PGC undergo in culture, the methylation status of embryonic germ cells (EGCs) derived from PGC at Day 26 of pregnancy was examined. Centromeric repeats and IGF2-H19 DMD sequences were similarly methylated in both male and female EGC and hypermethylated in female EGC compared with female PGC at the same embryonic age. Our results show that, similar to murine PGC, porcine PGC undergo genome-wide DNA demethylation shortly after arrival in the genital ridges. When placed in culture porcine PGC terminate their demethylation program and may acquire new DNA methylation marks. To our knowledge, this is the first report regarding epigenetic re-programming of genital ridge PGC in the pig. PMID:18425774

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

    ClinicalTrials.gov

    2016-02-09

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

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

    PubMed Central

    Tomes, N

    2000-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  18. A primary analysis of microwave brightness temperature of lunar surface from Chang-E 1 multi-channel radiometer observation and inversion of regolith layer thickness

    NASA Astrophysics Data System (ADS)

    Fa, Wenzhe; Jin, Ya-Qiu

    2010-06-01

    In China's first lunar exploration project, Chang-E 1 (CE-1), a multi-channel microwave radiometer was aboard the satellite, with the purpose of measuring microwave brightness temperature (Tb) from lunar surface and surveying the global distribution of lunar regolith layer thickness. In this paper, the primary 621 tracks of swath data measured by CE-1 microwave radiometer from November 2007 to February 2008 are collected and analyzed. Using the nearest neighbor interpolation to collect the Tb data under the same Sun illumination, global distributions of microwave brightness temperature from lunar surface at lunar daytime and nighttime are constructed. Based on the three-layer media modeling (the top dust-soil, regolith and underlying rock media) for microwave thermal emission of lunar surface, the CE-1 measured Tb and its dependence upon latitude, frequency and FeO + TiO 2 content, etc. are discussed. The CE-1 Tb data at Apollo landing sites are especially chosen for validation and calibration on the basis of available ground measurements. Using the empirical dependence of physical temperature upon the latitude verified by the CE-1 multi-channel Tb data at Apollo landing sites, the global distribution of regolith layer thickness is further inverted from the CE-1 brightness temperature data at 3 GHz channel. Those inversions at Apollo landing sites and the characteristics of regolith layer thickness for lunar maria are well compared with the Apollo in situ measurements and the regolith thickness derived from the Earth-based radar data. Finally, the statistical distribution of regolith thickness is analyzed and discussed.

  19. Establishment and in vitro culture of porcine spermatogonial germ cells in low temperature culture conditions.

    PubMed

    Lee, Won-Young; Park, Hyun-Jung; Lee, Ran; Lee, Kyung-Hoon; Kim, Yong-Hee; Ryu, Buom-Yong; Kim, Nam-Hyung; Kim, Jin-Hoi; Kim, Jae-Hwan; Moon, Sung-Hwan; Park, Jin-Ki; Chung, Hak-Jae; Kim, Dong-Hoon; Song, Hyuk

    2013-11-01

    The objective of this study was to establish a porcine spermatogonial germ cell (pSGC) line and develop an in vitro culture system. Isolated total testicular cells (TTCs) from 5-day-old porcine testes were primary cultured at 31, 34, and 37°C. Although the time of colony appearance was delayed at 31°C, strong alkaline phosphatase staining, expressions of pluripotency marker genes such as OCT4, NANOG, and THY1, and the gene expressions of the undifferentiated germ cell markers PLZF and protein gene product 9.5 (PGP9.5) were identified compared to 34 and 37°C. Cell cycle analysis for both pSGC and feeder cells at the three temperatures revealed that more pSGCs were in the G2/M phase at 31°C than 37°C at the subculture stage. In vitro, pSGCs could stably maintain undifferentiated germ cell and stem cell characteristics for over 60days during culture at 31°C. Xenotransplantation of pSGCs to immune deficient mice demonstrated a successful colonization and localization on the seminiferous tubule basement membrane in the recipient testes. In conclusion, pSGCs from neonatal porcine were successfully established and cultured for long periods under a low temperature culture environment in vitro. PMID:24041805

  20. Testicular structure and germ cells morphology in salamanders

    PubMed Central

    Uribe, Mari Carmen; Mejía-Roa, Víctor

    2014-01-01

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

  1. 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

  2. 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

  3. 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.

  4. Mitochondrial morphology in human fetal and adult female germ cells.

    PubMed

    Motta, P M; Nottola, S A; Makabe, S; Heyn, R

    2000-07-01

    The aim of this study has been to observe, by electron microscopy, the morphological changes affecting mitochondria and associated organelles in the human female germ cell during oogenesis, maturation and fertilization. In the primordial germ cell (PGC), rounded mitochondria with a pale matrix and small vesicular cristae are disposed near the nucleus and significantly increase in number during PGC migration and settlement in the gonadal ridge, where they differentiate into oogonia. In these early stages of mammalian oogenesis, aggregates of mitochondria are typically clustered around or in close relationship with the nuage. In oocytes at early prophase stage, mitochondria proliferate while aligned along the outer surface of the nuclear membrane, contain a more dense matrix than before, and have lamellar cristae. Oocytes of primordial and primary follicles mostly contain round or irregular mitochondria whose matrix has become very light. These mitochondria show typical parallel, arched cristae, and are clustered near the nucleus with other organelles forming the Balbiani's vitelline body. When follicles grow, the mitochondria of the oocytes become even more numerous and are dispersed in the ooplasm. Both paranuclear accumulation and subsequent dispersion of mitochondria in the cytoplasm are likely to be regulated by microtubules. By ovulation, mitochondria are the most prominent organelles in the ooplasm. They form voluminous aggregates with smooth endoplasmic reticulum (SER) tubules and vesicles. These mitochondrial-SER aggregates (M-SER) and the mitochondrial-vesicle complexes (MV) could be involved in the production of a reservoir of substances or membranes anticipating subsequent fertilization and early embryogenesis. Just after fertilization, the mitochondria of the oocyte undergo a further substantial change in size, shape, and microtopography. In the pronuclear zygote, mitochondria concentrate around the pronuclei. During the first embryonic cleavage divisions, round or oval mitochondria with a dense matrix and few arched cristae are gradually replaced by elongated ones with a less dense matrix and numerous transverse cristae. A progressive reduction in size and number of M-SER aggregates and MV complexes also occurs. In summary, oocyte mitochondria show dynamic morphological changes as they increase in number and populate different cell domains within the oocyte. They form complex relationships with other cell organelles, according to the different energetic -metabolic needs of the cell during differentiation, maturation, and fertilization, and are ultimately inherited by the developing embryo, where they eventually assume a more typical somatic cell form. PMID:11041520

  5. SALL4 expression in germ cell and non-germ cell tumors: a systematic immunohistochemical study of 3215 cases.

    PubMed

    Miettinen, Markku; Wang, Zengfeng; McCue, Peter A; Sarlomo-Rikala, Maarit; Rys, Janusz; Biernat, Wojciech; Lasota, Jerzy; Lee, Yi-Shan

    2014-03-01

    The SALL4 transcription factor is associated with embryonic cell pluripotency and has been shown as a useful immunohistochemical marker for germ cell tumors. However, information of SALL4 distribution in normal human tissues and non-germ cell tumors is limited. In this study we examined normal human tissues and 3215 tumors for SALL4 expression using a monoclonal antibody 6E3 and automated immunohistochemistry. In a 10-week embryo, SALL4 was expressed in ovocytes, intestine, kidney, and some hepatocytes. In adult tissues, it was only detected in germ cells. SALL4 was consistently expressed in all germ cell tumors except some trophoblastic tumors and mature components of teratomas, in which it was selectively expressed in intestinal-like and some squamous epithelia. In non-germ cell carcinomas, SALL4 was detected in 20% of cases or more of serous carcinoma of the ovary, urothelial high-grade carcinoma, and gastric adenocarcinoma (especially the intestinal type). SALL4 was only rarely (? 5%) expressed in mammary, colorectal, prostatic, and squamous cell carcinomas. Many SALL4-positive carcinomas showed poorly differentiated patterns, and some showed positivity in most tumor cells mimicking the expression in germ cell tumors. SALL4 was commonly expressed in rhabdoid tumors of the kidney and extrarenal sites and in the Wilms tumor. Expression of SALL4 was rare in other mesenchymal and neuroendocrine tumors but was occasionally detected in melanoma, desmoplastic small round cell tumor, epithelioid sarcoma, and rhabdomyosarcoma. All hematopoietic tumors were negative. SALL4 is an excellent marker of nonteratomatous germ cell tumors, but it is also expressed in other tumors, sometimes extensively. Such expression may reflect stem cell-like differentiation and must be considered when using SALL4 as a marker for germ cell tumors. Observed lack of other pluripotency factors, OCT4 and NANOG, in SALL4-positive non-germ cell tumors can also be diagnostically helpful. PMID:24525512

  6. Sinonasal teratocarcinosarcoma with yolk sac elements: a neoplasm of somatic or germ cell origin?

    PubMed

    Thomas, Jaiyeola; Adegboyega, Patrick; Iloabachie, Kenny; Mooring, John Wesley; Lian, Timothy

    2011-04-01

    Sinonasal teratocarcinosarcoma is an uncommon, aggressive, morphologically heterogenous tumor composed of cells derived from the 3 somatic layers. A histogenetic origin from a multipotential adult somatic stem cell with divergent differentiation has been favored over a germ cell origin. This assumption has been based on the lack of germ cell elements and, until recently, the absence of demonstrable amplification of 12p. We report a case that exhibited foci of yolk sac elements with papillary structures and intracytoplasmic periodic acid-Schiff-positive, diastase-resistant, ?-fetoprotein-positive, hyaline globules. An expanded area of undifferentiated cells, likely precursor cells, in the basal layer of the overlying mucosal epithelium transitions into and merges with the immature epithelial, neuroepithelial, and mesenchymal components. These previously unreported histomorphological features support the hypothesis that this tumor is a teratomatous tumor arising from pluripotent embryonic stem cells in the basal layer of the sinonasal epithelium. That notion is further supported by fluorescence in situ hybridization cytogenetic analysis, which showed a distinct subpopulation of the tumor cells with an extra copy of chromosome 12p13. PMID:20952296

  7. 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.

  8. Expression of axolotl DAZL RNA, a marker of germ plasm: widespread maternal RNA and onset of expression in germ cells approaching the gonad.

    PubMed

    Johnson, A D; Bachvarova, R F; Drum, M; Masi, T

    2001-06-15

    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 cloned a DAZ-like sequence from axolotls, Axdazl. Axdazl is homologous to Xdazl, a component of Xenopus germ plasm found in the vegetal pole of oocytes and eggs. Axdazl RNA is not localized in axolotl oocytes, and, furthermore, these oocytes do not contain the mitochondrial cloud that localizes Xdazl and other germ plasm components in Xenopus. Maternal Axdazl RNA is inherited in the animal cap and equatorial region of early embryos. At gastrula, neurula, and tailbud stages, Axdazl RNA is widely distributed. Axdazl first shows cell-specific expression in primordial germ cells (PGCs) approaching the gonad at stage 40, when nuage (germ plasm) appears in PGCs. These results suggest that, in axolotls, germ plasm components are insufficient to specify germ cells. PMID:11397009

  9. Female germ cell loss from radiation and chemical exposures

    SciTech Connect

    Dobson, R.L.; Felton, J.S.

    1983-01-01

    Female germ cells in some mammals are extremely sensitive to killing by ionizing radiation, especially during development. Primordial oocytes in juvenile mice have an LD50 of only 6-7 rad, and the germ cell pool in squirrel monkeys is destroyed by prenatal exposure of 0.7 rad/day. Sensitivity varies greatly with species and germ cell stage. Unusually high sensitivity has not been found in macaques and may not occur in man, but this has not been established for all developmental stages. The exquisite oocyte radiosensitivity in mice apparently reflects vulnerability of the plasma membrane, not DNA, which may have implications for estimating human genetic risks. Germ cells can be killed also by chemicals. Such oocyte loss, with similarities to radiation effects, is under increasing study, including chemotherapy observations in women. More than 75 compounds have been tested in mice, with in vivo toxicity quantified by oocyte loss; certain chemicals apparently act on the membrane.

  10. Aging and the germ line: where mortality and immortality meet.

    PubMed

    Jones, D Leanne

    2007-01-01

    Germ cells are highly specialized cells that form gametes, and they are the only cells within an organism that contribute genes to offspring. Germline stem cells (GSCs) sustain gamete production, both oogenesis (egg production) and spermatogenesis (sperm production), in many organisms. Since the genetic information contained within germ cells is passed from generation to generation, the germ line is often referred to as immortal. Therefore, it is possible that germ cells possess unique strategies to protect and transmit the genetic information contained within them indefinitely. However, aging often leads to a dramatic decrease in gamete production and fecundity. In addition, single gene mutations affecting longevity often have a converse effect on reproduction. Recent studies examining age-related changes in GSC number and activity, as well as changes to the stem cell microenvironment, provide insights into the mechanisms underlying the observed reduction in gametogenesis over the lifetime of an organism. PMID:17917132

  11. Could Germ from Cat Poop Trigger Rage Disorder in People?

    MedlinePLUS

    ... medlineplus/news/fullstory_157922.html Could Germ From Cat Poop Trigger Rage Disorder in People? Those with ... 2016 WEDNESDAY, March 23, 2016 (HealthDay News) -- Your cat's litter box could be a source of explosive ...

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

    MedlinePLUS

    ... around you from getting sick. 4. Clean your hands. Washing your hands often will help protect you from germs. If ... water are not available, use an alcohol-based hand rub. 5. Avoid touching your eyes, nose or ...

  13. Germ Cell Transplantation and Testis Tissue Xenografting in Mice

    PubMed Central

    Dobrinski, Ina

    2012-01-01

    Germ cell transplantation was developed by Dr. Ralph Brinster and colleagues at the University of Pennsylvania in 19941,2. These ground-breaking studies showed that microinjection of germ cells from fertile donor mice into the seminiferous tubules of infertile recipient mice results in donor-derived spermatogenesis and sperm production by the recipient animal2. The use of donor males carrying the bacterial ?-galactosidase gene allowed identification of donor-derived spermatogenesis and transmission of the donor haplotype to the offspring by recipient animals1. Surprisingly, after transplantation into the lumen of the seminiferous tubules, transplanted germ cells were able to move from the luminal compartment to the basement membrane where spermatogonia are located3. It is generally accepted that only SSCs are able to colonize the niche and re-establish spermatogenesis in the recipient testis. Therefore, germ cell transplantation provides a functional approach to study the stem cell niche in the testis and to characterize putative spermatogonial stem cells. To date, germ cell transplantation is used to elucidate basic stem cell biology, to produce transgenic animals through genetic manipulation of germ cells prior to transplantation4,5, to study Sertoli cell-germ cell interaction6,7, SSC homing and colonization3,8, as well as SSC self-renewal and differentiation9,10. Germ cell transplantation is also feasible in large species11. In these, the main applications are preservation of fertility, dissemination of elite genetics in animal populations, and generation of transgenic animals as the study of spermatogenesis and SSC biology with this technique is logistically more difficult and expensive than in rodents. Transplantation of germ cells from large species into the seminiferous tubules of mice results in colonization of donor cells and spermatogonial expansion, but not in their full differentiation presumably due to incompatibility of the recipient somatic cell compartment with the germ cells from phylogenetically distant species12. An alternative approach is transplantation of germ cells from large species together with their surrounding somatic compartment. We first reported in 2002, that small fragments of testis tissue from immature males transplanted under the dorsal skin of immunodeficient mice are able to survive and undergo full development with the production of fertilization competent sperm13. Since then testis tissue xenografting has been shown to be successful in many species and emerged as a valuable alternative to study testis development and spermatogenesis of large animals in mice14. PMID:22330955

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

    ClinicalTrials.gov

    2015-11-16

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

  15. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  17. Translational control in the C. elegans hermaphrodite germ line.

    PubMed

    Racher, Hilary; Hansen, Dave

    2010-02-01

    The formation of a fully developed gamete from an undifferentiated germ cell requires progression through numerous developmental stages and cell fate decisions. The precise timing and level of gene expression guides cells through these stages. Translational regulation is highly utilized in the germ line of many species, including Caenorhabditis elegans, to regulate gene expression and ensure the proper formation of gametes. In this review, we discuss some of the developmental stages and cell fate decisions involved in the formation of functional gametes in the C. elegans germ line in which translational control has been implicated. These stages include the mitosis versus meiosis decision, the sperm/oocyte decision, and gamete maturation. We also discuss some of the techniques used to identify mRNA targets; the identification of these targets is necessary to clearly understand the role each RNA-binding protein plays in these decisions. Relatively few mRNA targets have been identified, thus providing a major focus for future research. Finally, we propose some reasons why translational control may be utilized so heavily in the germ line. Given that many species have this substantial reliance on translational regulation for the control of gene expression in the germ line, an understanding of translational regulation in the C. elegans germ line is likely to increase our understanding of gamete formation in general. PMID:20140027

  18. Sexual plasticity of ovarian germ cells in rainbow trout.

    PubMed

    Yoshizaki, Goro; Ichikawa, Masaki; Hayashi, Makoto; Iwasaki, Yoshiko; Miwa, Misako; Shikina, Shinya; Okutsu, Tomoyuki

    2010-04-01

    The sexual plasticity of fish gonads declines after the sex differentiation period; however, information about the plasticity of the germ cells themselves after sex differentiation is limited. Using rainbow trout (Oncorhynchus mykiss), we recently established a novel germ cell transplantation system that provides a unique platform with which to dissect the developmental and cellular mechanisms underlying gametogenesis. Using this technique, we show here that transplanted ovarian germ cells isolated from 6- to 9-month-old donors can colonize sexually undifferentiated embryonic gonads and resume gametogenesis. Ovarian germ cells containing oogonia and early oocytes isolated from female rainbow trout were transplanted into the peritoneal cavities of hatching-stage fry of both sexes and the behavior of the donor cells was observed. The transplanted ovarian germ cells migrated towards the recipient gonads, interacted with embryonic gonadal somatic cells, proliferated rapidly, and eventually differentiated into eggs in female recipients and sperm in male recipients. Furthermore, the donor-derived eggs and sperm obtained from the recipient fish were functional and were able to produce normal offspring. These findings indicate that mitotic germ cells, the oogonia, possess a high level of sexual plasticity. PMID:20223765

  19. Derivation of germ cells from mouse embryonic stem cells.

    PubMed

    Wu, Ming-Yih; Chow, Song-Nan

    2005-10-01

    Deriving oocytes from mouse embryonic stem (ES) cells in the laboratory would be a major advance in therapeutic cloning from today's insufficient process. The first step in this attempt is to study the precursors - primordial germ cells (PGCs), including their emergence, presentation, migration and differentiation. By comparing various reported antigens of germ cells, we found stage-specific embryonic antigen-1 (SSEA-1) and Octamer-4 (Oct-4) are the most useful markers to verify the growth and maturation of germ cell culture from mice. Transgenic mice with specific antigens such as SSEA-1 or Oct-4 are helpful to pick up colonies and follow PGC differentiation. We also delineate the physiological structure for germ cell development by reviewing important studies which employed re-aggregation methods to make germ cells more mature and ready for clinical use. Although some mysteries about reprogramming and intragonadal signal interactions still remain unsolved, each step in uncovering these mechanisms will bring us closer to establishing an unlimited source of germ cells from ES cells. PMID:16385371

  20. Perspectives of germ cell development in vitro in mammals

    PubMed Central

    Hayashi, Katsuhiko; Saitou, Mitinori

    2014-01-01

    Pluripotent stem cells, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are able to differentiate into all cell lineages of the embryo proper, including germ cells. This pluripotent property has a huge impact on the fields of regenerative medicine, developmental biology and reproductive engineering. Establishing the germ cell lineage from ESCs/iPSCs is the key biological subject, since it would contribute not only to dissection of the biological processes of germ cell development but also to production of unlimited numbers of functional gametes in vitro. Toward this goal, we recently established a culture system that induces functional mouse primordial germ cells (PGCs), precursors of all germ cells, from mouse ESCs/iPSCs. The successful in vitro production of PGCs arose from the study of pluripotent cell state, the signals inducing PGCs and the technology of transplantation. However, there are many obstacles to be overcome for the robust generation of mature gametes or for application of the culture system to other species, including humans and livestock. In this review, we discuss the requirements for a culture system to generate the germ cell lineage from ESCs/iPSCs. PMID:24725251

  1. Transgenic Rodent Assay for Quantifying Male Germ Cell Mutant Frequency

    PubMed Central

    O'Brien, Jason M.; Beal, Marc A.; Gingerich, John D.; Soper, Lynda; Douglas, George R.; Yauk, Carole L.; Marchetti, Francesco

    2014-01-01

    De novo mutations arise mostly in the male germline and may contribute to adverse health outcomes in subsequent generations. Traditional methods for assessing the induction of germ cell mutations require the use of large numbers of animals, making them impractical. As such, germ cell mutagenicity is rarely assessed during chemical testing and risk assessment. Herein, we describe an in vivo male germ cell mutation assay using a transgenic rodent model that is based on a recently approved Organisation for Economic Co-operation and Development (OECD) test guideline. This method uses an in vitro positive selection assay to measure in vivo mutations induced in a transgenic λgt10 vector bearing a reporter gene directly in the germ cells of exposed males. We further describe how the detection of mutations in the transgene recovered from germ cells can be used to characterize the stage-specific sensitivity of the various spermatogenic cell types to mutagen exposure by controlling three experimental parameters: the duration of exposure (administration time), the time between exposure and sample collection (sampling time), and the cell population collected for analysis. Because a large number of germ cells can be assayed from a single male, this method has superior sensitivity compared with traditional methods, requires fewer animals and therefore much less time and resources. PMID:25145276

  2. Decreased expression of cold-inducible RNA-binding protein (CIRP) in male germ cells at elevated temperature.

    PubMed Central

    Nishiyama, H.; Danno, S.; Kaneko, Y.; Itoh, K.; Yokoi, H.; Fukumoto, M.; Okuno, H.; Millán, J. L.; Matsuda, T.; Yoshida, O.; Fujita, J.

    1998-01-01

    Physiological scrotal hypothermia is necessary for normal spermatogenesis and fertility in mammals. Cirp is a recently identified cold-inducible RNA-binding protein that is inducible at 32 degrees C in mouse somatic cells in vitro. Cirp is constitutively expressed in the testis of mouse and structurally highly similar to RBM1, a candidate for the human azoospermia factor. To elucidate the role played by Cirp in spermatogenesis, we investigated its expression levels during spermatogenesis and after heat stress. In the mouse testis, cirp mRNA was detected in the germ cells, and the level varied depending on the stage of differentiation. Also, a high level of Cirp protein was detected immunohistochemically in the nucleus of primary spermatocytes. Expression of Cirp was decreased in the GC-2spd(ts) mouse germ cell line when culture temperature was raised from 32 degrees C to 37 degrees C. When mouse testis was exposed to heat stress by experimental cryptorchidism or immersion of the lower abdomen in warm (42 degrees C) water, the expression of Cirp was decreased in the testis within 6 hours after either treatment. In human testis with varicocele analyzed immunohistochemically, germ cells expressed less Cirp protein than those in the testis without varicocele. These results demonstrated that CIRP expression is down-regulated at elevated temperature in male germ cells of mice and humans. Analysis of Cirp expression in the testes will help elucidate the molecular mechanisms leading to male infertility. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9422546

  3. Retinoic acid metabolism links the periodical differentiation of germ cells with the cycle of Sertoli cells in mouse seminiferous epithelium.

    PubMed

    Sugimoto, Ryo; Nabeshima, Yo-ichi; Yoshida, Shosei

    2012-01-01

    Homeostasis of tissues relies on the regulated differentiation of stem cells. In the epithelium of mouse seminiferous tubules, the differentiation process from undifferentiated spermatogonia (A(undiff)), which harbor the stem cell functions, to sperm occurs in a periodical manner, known as the "seminiferous epithelial cycle". To identify the mechanism underlying this periodic differentiation, we investigated the roles of Sertoli cells (the somatic supporting cells) and retinoic acid (RA) in the seminiferous epithelial cycle. Sertoli cells cyclically change their functions in a coordinated manner with germ cell differentiation and support the entire process of spermatogenesis. RA is known to play essential roles in this periodic differentiation, but its precise mode of action and its regulation remains largely obscure. We showed that an experimental increase in RA signaling was capable of both inducing A(undiff) differentiation and resetting the Sertoli cell cycle to the appropriate stage. However, these actions of exogenous RA signaling on A(undiff) and Sertoli cells were strongly interfered by the differentiating germ cells of intimate location. Based on the expression of RA metabolism-related genes among multiple cell types - including germ and Sertoli cells - and their regulation by RA signaling, we propose here that differentiating germ cells play a primary role in modulating the local RA metabolism, which results in the timed differentiation of A(undiff) and the appropriate cycling of Sertoli cells. Similar regulation by differentiating progeny through the modulation of local environment could also be involved in other stem cell systems. PMID:22200512

  4. Germs are Germs, and Why Not Take a Risk?: Patients’ Expectations for Prescribing Antibiotics in an Inner City Emergency Department

    PubMed Central

    Broniatowski, David A.; Klein, Eili Y.; Reyna, Valerie F.

    2014-01-01

    Background Extensive use of unnecessary antibiotics has driven the emergence of resistant bacterial strains, posing a threat to public health. Physicians are more likely to prescribe antibiotics when they believe that patients expect them. Current attempts to change these expectations highlight the distinction between viruses and bacteria (“Germs are Germs”). Fuzzy Trace Theory further predicts that patients expect antibiotics because they make decisions based on categorical gist, producing strategies that encourage risk taking when the status quo is bad (i.e., “Why Not Take a Risk?”). We investigate both hypotheses. Methods We surveyed patients visiting the emergency department of a large urban hospital (72, 64%, were African-American) using 17 Likert-scale questions and two free-response questions regarding patient expectations for antibiotics. Results After the clinical encounter, 113 patients completed the survey. 54 (48%) patients agreed with items that assess the “Germs are Germs” hypothesis, whereas 86 (76%) agreed with items that assess the “Why Not Take a Risk?” hypothesis. “Why Not Take a Risk?” captures significant unique variance in a factor analysis, and is neither explained by “Germs are Germs,” nor by patients’ lack of knowledge regarding side effects. Of the 81 patients who rejected the “Germs are Germs” hypothesis, 61 (75%) still indicated agreement with the “Why Not Take a Risk?” hypothesis. Several other misconceptions were also investigated. Conclusions Our findings suggest that recent public health campaigns that have focused on educating patients about the differences between viruses and bacteria omit a key motivation for why patients expect antibiotics, supporting Fuzzy Trace Theory’s predictions about categorical gist. The implications for public health and emergency medicine are discussed. PMID:25331913

  5. Restricted distribution of mrg-1 mRNA in C. elegans primordial germ cells through germ granule-independent regulation.

    PubMed

    Miwa, Takashi; Takasaki, Teruaki; Inoue, Kunio; Sakamoto, Hiroshi

    2015-11-01

    The chromodomain protein MRG-1 is an essential maternal factor for proper germline development that protects germ cells from cell death in C. elegans. Unlike germ granules, which are exclusively segregated to the germline blastomeres at each cell division from the first cleavage of the embryo, MRG-1 is abundant in all cells in early embryos and is then gradually restricted to the primordial germ cells (PGCs) by the morphogenesis stage. Here, we show that this characteristic spatiotemporal expression pattern is dictated by the mrg-1 3'UTR and is differentially regulated at the RNA level between germline and somatic cells. Asymmetric segregation of germ granules is not necessary to localize MRG-1 to the PGCs. We found that MES-4, an essential chromatin regulator in germ cells, also accumulates in the PGCs in a germ granule-independent manner. We propose that C.elegans PGCs have a novel mechanism to accumulate at least some chromatin-associated proteins that are essential for germline immortality. PMID:26537333

  6. 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

  7. Activity of nintedanib in germ cell tumors.

    PubMed

    Steinemann, Gustav; Jacobsen, Christine; Gerwing, Mirjam; Hauschild, Jessica; von Amsberg, Gunhild; Höpfner, Michael; Nitzsche, Bianca; Honecker, Friedemann

    2016-02-01

    Germ cell tumors (GCTs) are the most frequent malignancy in male patients between 15 and 45 years of age. Cisplatin-based chemotherapy shows excellent cure rates, but patients with cisplatin-resistant GCTs have a poor prognosis. Nintedanib (BIBF 1120, Vargatef) inhibits the receptor classes vascular endothelial growth factor receptor, platelet derived growth factor receptor, and fibroblast growth factor receptor, and has shown activity against many tumors, as well as in idiopathic lung fibrosis and bleomycin-induced lung injury. Here, we investigated the antineoplastic and antiangiogenic properties of nintedanib in cisplatin-resistant and cisplatin-sensitive GCT cells, both alone and in combination with classical cytotoxic agents such as cisplatin, etoposide, and bleomycin. The half-maximal inhibitory concentration (IC50) of nintedanib was 4.5±0.43??mol/l, 3.1±0.45??mol/l, and 3.6±0.33??mol/l in cisplatin-sensitive NTERA2, 2102Ep, and NCCIT cells, whereas the IC50 doses of the cisplatin-resistant counterparts were 6.6±0.37??mol/l (NTERA2-R), 4.5±0.83??mol/l (2102Ep-R), and 6.1±0.41??mol/l (NCCIT-R), respectively. Single treatment with nintedanib induced apoptosis and resulted in a sustained reduction in the capacity of colony formation in both cisplatin-sensitive and cisplatin-resistant GCT cells. Cell cycle analysis showed that nintedanib induced a strong G0/G1-phase arrest in all investigated cell lines. Combination treatment with cisplatin did not result in additive, synergistic, or antagonistic effects. The in-vivo activity was studied using the chorioallantoic membrane assay and indicated the antiangiogenic potency of nintedanib with markedly reduced microvessel density. Topical treatment of inoculated tumor plaques resulted in a significant reduction of the tumor size. This indicates that nintedanib might be a promising substance in the treatment of GCT. PMID:26479145

  8. The chemosensitivity of testicular germ cell tumors.

    PubMed

    Voutsadakis, Ioannis A

    2014-04-01

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

  9. Specification of primordial germ cells in medaka (Oryzias latipes)

    PubMed Central

    Herpin, Amaury; Rohr, Stefan; Riedel, Dietmar; Kluever, Nils; Raz, Erez; Schartl, Manfred

    2007-01-01

    Background Primordial germ cells (PGCs) give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes). Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of maternally provided asymmetrically-localized cytoplasmic determinants directs cells to assume the germ line fate similar to zebrafish PGCs. PMID:17217535

  10. Apparent diffusion coefficient of intracranial germ cell tumors.

    PubMed

    Ogiwara, Hideki; Tsutsumi, Yoshiyuki; Matsuoka, Kentarou; Kiyotani, Chikako; Terashima, Keita; Morota, Nobuhito

    2015-02-01

    The role of diffusion weighted imaging and apparent diffusion coefficient in intracranial germ cell tumors has not been fully elucidated. The aim of this study was to evaluate whether the ADC correlates with the histologic subtypes of germ cell tumors. We also aimed to investigate whether the ADC values can predict treatment response. The authors retrospectively analyzed the ADC values of the enhancing and solid regions of germ cell tumors. The absolute ADC values and the normalized ADC values were compared among different histologic diagnoses. The ADC values before and after the first course of chemotherapy were also compared between the different prognostic groups. Ten patients were included in the study. The median age at diagnosis was 9.3 years (range 5.3-13.8 years). There were four patients with germinoma and six patients with nongerminomatous germ cell tumor (NGGCT) including five mixed germ cell tumors and one immature teratoma. The mean absolute and normalized ADC values (×10(-3) mm(2)/s) were significantly lower in germinomas [0.835 ± 0.065 (standard deviation) and 1.11 ± 0.096, respectively] than in NGGCTs (1.271 ± 0.145 and 1.703 ± 0.223, respectively) (p = 0.01). The ADC values before and after the first course of chemotherapy were available in four patients. The ADC value after the first chemotherapy had a tendency to increase more in patients who eventually demonstrated complete response with chemotherapy than in patients who required second-look surgery. Assessment of the ADC values of germ cell tumors is considered to facilitate differentiation of histological subtypes of germ cell tumors. Evaluation of the ADC may also be useful for predicting treatment response. PMID:25413617

  11. Follistatin regulates germ cell nest breakdown and primordial follicle formation.

    PubMed

    Kimura, Fuminori; Bonomi, Lara M; Schneyer, Alan L

    2011-02-01

    Follistatin (FST) is an antagonist of activin and related TGF? superfamily members that has important reproductive actions as well as critical regulatory functions in other tissues and systems. FST is produced as three protein isoforms that differ in their biochemical properties and in their localization within the body. We created FST288-only mice that only express the short FST288 isoform and previously reported that females are subfertile, but have an excess of primordial follicles on postnatal day (PND) 8.5 that undergo accelerated demise in adults. We have now examined germ cell nest breakdown and primordial follicle formation in the critical PND 0.5-8.5 period to test the hypothesis that the excess primordial follicles derive from increased proliferation and decreased apoptosis during germ cell nest breakdown. Using double immunofluorescence microscopy we found that there is virtually no germ cell proliferation after birth in wild-type or FST288-only females. However, the entire process of germ cell nest breakdown was extended in time (through at least PND 8.5) and apoptosis was significantly reduced in FST288-only females. In addition, FST288-only females are born with more germ cells within the nests. Thus, the excess primordial follicles in FST288-only mice derive from a greater number of germ cells at birth as well as a reduced rate of apoptosis during nest breakdown. These results also demonstrate that FST is critical for normal regulation of germ cell nest breakdown and that loss of the FST303 and/or FST315 isoforms leads to excess primordial follicles with accelerated demise, resulting in premature cessation of ovarian function. PMID:21106872

  12. Follistatin Regulates Germ Cell Nest Breakdown and Primordial Follicle Formation

    PubMed Central

    Kimura, Fuminori; Bonomi, Lara M.

    2011-01-01

    Follistatin (FST) is an antagonist of activin and related TGF? superfamily members that has important reproductive actions as well as critical regulatory functions in other tissues and systems. FST is produced as three protein isoforms that differ in their biochemical properties and in their localization within the body. We created FST288-only mice that only express the short FST288 isoform and previously reported that females are subfertile, but have an excess of primordial follicles on postnatal day (PND) 8.5 that undergo accelerated demise in adults. We have now examined germ cell nest breakdown and primordial follicle formation in the critical PND 0.5–8.5 period to test the hypothesis that the excess primordial follicles derive from increased proliferation and decreased apoptosis during germ cell nest breakdown. Using double immunofluorescence microscopy we found that there is virtually no germ cell proliferation after birth in wild-type or FST288-only females. However, the entire process of germ cell nest breakdown was extended in time (through at least PND 8.5) and apoptosis was significantly reduced in FST288-only females. In addition, FST288-only females are born with more germ cells within the nests. Thus, the excess primordial follicles in FST288-only mice derive from a greater number of germ cells at birth as well as a reduced rate of apoptosis during nest breakdown. These results also demonstrate that FST is critical for normal regulation of germ cell nest breakdown and that loss of the FST303 and/or FST315 isoforms leads to excess primordial follicles with accelerated demise, resulting in premature cessation of ovarian function. PMID:21106872

  13. Intratubular germ cell neoplasia of the testis: a brief review.

    PubMed

    Al-Hussain, Turki; Bakshi, Nasir; Akhtar, Mohammed

    2015-05-01

    Germ cell tumors of the testis may be divided into 3 broad categories according to age at presentation. The tumors in the pediatric age group include teratoma and yolk sac tumor. These tumors are generally not associated with convincing intratubular neoplasia. The second group consists of tumors presenting in third and fourth decade of life and include seminoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, and teratoma as well as mixed germ cell tumors. The precursor cell for these tumors is an abnormal gonocyte that fails to differentiate completely into spermatogonia. These abnormal cells stay dormant in the gonad during intrauterine life as well as infancy and childhood, but undergo proliferation during puberty and can be identified as intratubular germ cell neoplasia unclassified (IGCNU). These tumor cells continue to manifest protein expression pattern that resembles primitive germ cells (PLAP, c-KIT, OCT3/4). After a variable interval following puberty, IGCNU cells may acquire ability to penetrate the seminiferous tubules and present as an overt germ cell tumor. Acquisition of isochrome 12 and other genetic abnormalities are usually associated with this transition. The level of DNA methylation generally determines the phenotype of the germ cell tumor. The third type of germ cell tumors is spermatocytic seminoma, which is a rare tumor encountered later in life usually in fifth and sixth decade. The cell of origin of this tumor is probably postpubertal mature spermatogonia which acquire abnormal proliferative capability probably due to gain of chromosome 9 resulting in activation and amplification of genes such as DMRT1. The tumor cells manifest many of the proteins normally expressed by mature sperms such as VASA, SSX2, and occasionally OCT2. Although spermatocytic seminoma may also have an intratubular growth phase, it completely lacks features of IGCNU. PMID:25844678

  14. Identification of Novel Fusion Genes in Testicular Germ Cell Tumors.

    PubMed

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

    2016-01-01

    Testicular germ cell tumors (TGCT) are the most frequently diagnosed solid tumors in young men ages 15 to 44 years. Embryonal carcinomas (EC) comprise a subset of TGCTs that exhibit pluripotent characteristics similar to embryonic stem (ES) cells, but the genetic drivers underlying malignant transformation of ECs are unknown. To elucidate the abnormal genetic events potentially contributing to TGCT malignancy, such as the existence of fusion genes or aberrant fusion transcript expression, we performed RNA sequencing of EC cell lines and their nonmalignant ES cell line counterparts. We identified eight novel fusion transcripts and one gene with alternative promoter usage, ETV6. Four out of nine transcripts were found recurrently expressed in an extended panel of primary TGCTs and additional EC cell lines, but not in normal parenchyma of the testis, implying tumor-specific expression. Two of the recurrent transcripts involved an intrachromosomal fusion between RCC1 and HENMT1 located 80 Mbp apart and an interchromosomal fusion between RCC1 and ABHD12B. RCC1-ABHD12B and the ETV6 transcript variant were found to be preferentially expressed in the more undifferentiated TGCT subtypes. In vitro differentiation of the NTERA2 EC cell line resulted in significantly reduced expression of both fusion transcripts involving RCC1 and the ETV6 transcript variant, indicating that they are markers of pluripotency in a malignant setting. In conclusion, we identified eight novel fusion transcripts that, to our knowledge, are the first fusion genes described in TGCT and may therefore potentially serve as genomic biomarkers of malignant progression. Cancer Res; 76(1); 108-16. ©2015 AACR. PMID:26659575

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

    PubMed Central

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

    2009-01-01

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

  16. 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.

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

    PubMed Central

    Moreno, Ricardo D.

    2014-01-01

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

  18. Germ cell nuclear factor regulates gametogenesis in developing gonads.

    PubMed

    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

  19. 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

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

    SciTech Connect

    Mailhes, J B; Marchetti, F

    2004-10-15

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

  1. Immunolocalization of albumin and transferrin in germ cells and Sertoli cells during rat gonadal morphogenesis and postnatal development of the testis.

    PubMed

    Gelly, J L; Richoux, J P; Grignon, G

    1994-05-01

    The localization of albumin and transferrin was examined immunohistochemically in germ cells and Sertoli cells during rat gonadal morphogenesis and postnatal development of the testis. These proteins appeared as early as the 13th day of gestation in migrating primordial germ cells before Sertoli cell differentiation. In the fetal testis, strong immunoreactivity was only detected in the gonocytes. In the prepubertal testis, spermatogonia, primary spermatocytes, and some Sertoli cells accumulate albumin and transferrin. At puberty, different patterns of immunostaining of the germ cells were observed at the various stages of the cycle of the seminiferous epithelium. Diplotene spermatocytes at stage XIII, spermatocytes in division at stage XIV, and round spermatids at stages IV-VIII showed maximal staining. Labeling was evident in the cytoplasm of adult Sertoli cells. Albumin and transferrin staining patterns paralleled each other during ontogenesis. PMID:8020066

  2. The Galactic Ecosystems Research and Mentorship (GERM) Initiative

    NASA Astrophysics Data System (ADS)

    Waller, William H.

    2009-01-01

    The Galactic Ecosystems Research and Mentorship (GERM) Initiative was established as a means of catalyzing engagement of Tufts University students in research and education relating to the inner workings of star-forming galaxies such as our own Milky Way galaxy. To date, the GERM Initiative has led to the creation of a seminar course on Galactic Ecosystems at Tufts, multiple papers and presentations by experts and students which are archived at http://go.tufts.edu/galacticecosystems, research collaborations at the Harvard-Smithsonian Center for Astrophysics, and an emerging relationship with the Clay Center Observatory to carry out narrowband imaging of galactic star-forming regions. We are grateful for funding support from the Massachusetts Space Grant Consortium and the AAS Small Research Grant Program. Pending further support, the GERM Initiative could be expanded to involve a significantly larger cohort of students and researchers in the Boston area.

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

    PubMed Central

    2013-01-01

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

  4. Functional analysis of the Drosophila embryonic germ cell transcriptome by RNA interference.

    PubMed

    Jankovics, Ferenc; Henn, László; 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

  5. The nuts and bolts of germ-cell migration.

    PubMed

    Tarbashevich, Katsiaryna; Raz, Erez

    2010-12-01

    In many species, primordial germ cells (PGCs) migrate from the position where they are specified to the site where the gonad develops, where they differentiate into sperm and egg. Germ cells thus serve as an excellent model for studying cell migration in the context of the live organism. In recent years, a number of cues directing the migration of the cells towards their target were identified and some of the relevant molecules and biochemical pathways were revealed. In this review we present those results, focusing on 'cell mechanics' of the process including cell adhesion, traction generation and cell polarization. PMID:20947321

  6. Results of Pulmonary Resection: Sarcoma and Germ Cell Tumors.

    PubMed

    Ceppa, DuyKhanh P

    2016-02-01

    Pulmonary metastasis occurs in as many as 88% and 80% of stage IV patients with sarcoma and germ cell tumors, respectively. Pulmonary metastatectomy may be the only means of rendering a patient disease free. Sublobar resection (wedge or segmentectomy), lobectomy, and pneumonectomy achieve complete resection. Bilateral disease can be resected via staged thoracoscopy/thoracotomy, median sternotomy, or clamshell thoracotomy. Multiple resections and re-resections have resulted in improved survival. Five-year survival rates as high as 35% to 52% for sarcoma and 80% for germ cell tumor can be realized. PMID:26611510

  7. A caprine chimera produced by injection of embryonic germ cells into a blastocyst.

    PubMed

    Jia, W; Yang, W; Lei, A; Gao, Z; Yang, C; Hua, J; Huang, W; Ma, X; Wang, H; Dou, Z

    2008-02-01

    This report details a chimeric goat derived by injecting caprine embryonic germ (EG) cells into a host blastocyst. The EG cells, isolated from the primordial genital ridge of white Guanzhong goat fetuses (28-42 days of pregnancy), had alkaline phosphatase activity and several stem cell markers, including SSEA-1, c-kit, and Nanog. Ten to 20EG cells were microinjected into the blastocoelic cavity of a host blastocyst collected from a black goat following natural service. Twenty-nine injected blastocysts were transferred into nine white surrogate goats. One of the recipients maintained pregnancy to term and gave birth to three kids: one male, one female, and a dead, malformed fetus of undetermined gender; all three fetuses were black, but the female and the malformed fetus each had a large white spot on their head. Based on PCR and microsatellite DNA assay, the female and the malformed fetus were monozygotic twins and chimeras. Microsatellite assay on various tissues from the dead fetus (including skin, blood, liver, placenta, lung, heart, spleen, muscle, and brain), revealed that these tissues and organs were chimeric and contained cells derived from EG cells. In conclusion, caprine EG cells differentiated into all three germ layers in vivo. PMID:18001826

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Soy germ protein concentrate diet decreased body fat weight and increased hindlimb muscle weight in rats.

    PubMed

    Kataoka, Hisashi; Saito, Sanshiro; Itoh, Atsushi; Matsuo, Tatsuhiro

    2012-01-01

    The purpose of this study was to investigate the effects of soy germ protein intake on body composition. Wistar rats were fed experimental diets for 16 weeks. These consisted of soy germ protein, soy protein, or casein. Abdominal adipose tissue weights significantly lower and hindlimb muscle weights were significantly higher in the soy germ protein group than in the casein group. PMID:22785474

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

    PubMed

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

    2003-08-29

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

  11. Effect of oil extraction method on the enzymatic digestibility of corn germ arabinoxylan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole corn germ and germs extracted by three different processes were all excellent substrates for arabinoxylan digestion by crude enzymes from Aureobasidium strain NRRL Y-2311-1. Thus, oil extraction does not serve as a pretreatment to enhance digestibility. Fully expelled germ was slightly more ...

  12. Protein in wet-milled corn germ recovered by ultrafiltration-diafiltration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate ultrafiltration-diafiltration (UF-DF) as a means to improve the extractability of wet-milled corn germ protein and determine its effects on the functional properties of the recovered protein product. Wet germ and finished (dried) germ proteins were extracted by u...

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

    ClinicalTrials.gov

    2015-11-16

    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

  14. 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

  15. 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

  16. Effect of KnockOut serum replacement on germ cell development of immature testis tissue culture.

    PubMed

    Liu, Feng; Cai, Chunhong; Wu, Xin; Cheng, Yanxia; Lin, Tao; Wei, Guanghui; He, Dawei

    2016-01-15

    To compare KnockOut serum replacement (KSR) and fetal bovine serum (FBS) for the development of germ cells. Testicular tissues from Sprague-Dawley rats were cultured for 4 weeks in culture media supplemented with FBS or KSR. Tissue area was measured at the beginning and end of the culturing period. Testicular histology, development of the germ cells, and the diameter of seminiferous tubules were analyzed by hematoxylin and eosin staining. After 4 weeks in culture, apoptosis and expression of the stage-specific spermatogenesis marker genes Kit, Sycp3, and Crisp1 were assayed. Tissues cultured in KSR-supplemented media were able to sustain growth and gradually increase seminiferous tubule diameter during the culture period. In addition, spermatogonia, primary spermatocytes, secondary spermatocytes, and round spermatids were observed after 4 weeks in culture, and reverse transcription-PCR confirmed expression of the marker genes. In comparison, tissues cultured in FBS-supplemented media showed dwindling testicular organization, necrotic seminiferous tubules, and expression of Kit, but inconsistent expression of Sycp3 and Crisp1 KnockOut serum replacement outperforms FBS as a growth media supplements for culturing immature spermatogonial tissue culture. PMID:26474686

  17. Seniors Often Bring Drug-Resistant Germs to Rehab Centers

    MedlinePLUS

    ... germs among more than 350 seniors, with an average age of 76. The study participants were being temporarily ... of Medicine, NYU Langone Medical Center, New York City; March 14, 2016, JAMA Internal Medicine , online HealthDay Copyright (c) 2016 HealthDay . All rights ... to RSS Follow us ...

  18. Preschoolers' Understanding of Germs as Causes of Illness.

    ERIC Educational Resources Information Center

    Kalish, Charles

    Two studies examined preschoolers' understanding of germs as causes of illness. Previous research suggests that preschoolers know that certain behaviors lead to illness without understanding why or how. In the first study, 22 children between 4 and 5 years old were presented with 12 brief stories describing characters engaged in either dangerous…

  19. 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...

  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. Fetal age estimation using MSCT scans of deciduous tooth germs.

    PubMed

    Minier, Marie; Maret, Delphine; Dedouit, Fabrice; Vergnault, Marion; Mokrane, Fathima-Zohra; Rousseau, Hervé; Adalian, Pascal; Telmon, Norbert; Rougé, Daniel

    2014-01-01

    Evaluation of fetal age is an essential element in many fields such as anthropology, odontology, paleopathology, and forensic sciences. This study examines the correlation between fetal age, femoral diaphyseal length (considered as the gold standard), and deciduous tooth germs of fetuses aged 22 to 40 weeks amenorrhea (WA) based on computed tomography (MSCT) reconstructions. Qualitative and quantitative studies of femoral and deciduous tooth germ lengths were performed on 81 fetuses (39 females and 42 males). R software was used for statistical analyses. Intra-observer and inter-observer variabilities and the interclass correlation coefficient (ICC) were calculated. Correlation coefficients (R (2)) and linear regression equations were calculated. Intra- and inter-observer variabilities were very satisfactory (intra-observer ICC ≥ 0.96, inter-observer ICC ≥ 0.95). Femoral length was significantly correlated with age (R (2) = 0.9). The correlation coefficient between age and height, width, and dental volume was R (2) ≥ 0.73. Tooth germs were good indicators of fetal age. Our method appears to be reliable and reproducible, and the results of this study agreed with those of the literature. The dental formula provided a precise estimation of fetal age between 25 and 32 WA. Tooth germs were reliable indicators of fetal age, and multislice computed tomography was shown to be an innovative and reliable technology for this purpose. PMID:23828625

  3. 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...

  4. An oncofetal and developmental perspective on testicular germ cell cancer.

    PubMed

    Rijlaarsdam, Martin A; Looijenga, Leendert H J

    2014-12-01

    Germ cell tumors (GCTs) represent a diverse group of tumors presumably originating from (early fetal) developing germ cells. Most frequent are the testicular germ cell cancers (TGCC). Overall, TGCC is the most frequent malignancy in Caucasian males (20-40 years) and remains an important cause of (treatment related) mortality in these young men. The strong association between the phenotype of TGCC stem cell components and their totipotent ancestor (fetal primordial germ cell or gonocyte) makes these tumors highly relevant from an onco-fetal point of view. This review subsequently discusses the evidence for the early embryonic origin of TGCCs, followed by an overview of the crucial association between TGCC pathogenesis, genetics, environmental exposure and the (fetal) testicular micro-environment (genvironment). This culminates in an evaluation of three genvironmentally modulated hallmarks of TGCC directly related to the oncofetal pathogenesis of TGCC: (1) maintenance of pluripotency, (2) cell cycle control/cisplatin sensitivity and (3) regulation of proliferation/migration/apoptosis by KIT-KITL mediated receptor tyrosine kinase signaling. Briefly, TGCC exhibit identifiable stem cell components (seminoma and embryonal carcinoma) and progenitors that show large and consistent similarities to primordial/embryonic germ cells, their presumed totipotent cells of origin. TGCC pathogenesis depends crucially on a complex interaction of genetic and (micro-)environmental, i.e. genvironmental risk factors that have only been partly elucidated despite significant effort. TGCC stem cell components also show a high degree of similarity with embryonic stem/germ cells (ES) in the regulation of pluripotency and cell cycle control, directly related to their exquisite sensitivity to DNA damaging agents (e.g. cisplatin). Of note, (ES specific) micro-RNAs play a pivotal role in the crossover between cell cycle control, pluripotency and chemosensitivity. Moreover, multiple consistent observations reported TGCC to be associated with KIT-KITL mediated receptor tyrosine kinase signaling, a pathway crucially implicated in proliferation, migration and survival during embryogenesis including germ cell development. In conclusion, TGCCs are a fascinating model for onco-fetal developmental processes especially with regard to studying cell cycle control, pluripotency maintenance and KIT-KITL signaling. The knowledge presented here contributes to better understanding of the molecular characteristics of TGCC pathogenesis, translating to identification of at risk individuals and enhanced quality of care for TGCC patients (diagnosis, treatment and follow-up). PMID:25066859

  5. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. 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

  8. 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

  9. 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

  10. Cross-Sectional Study of the Retinal Nerve Fiber Layer Thickness at 7 Years After an Acute Episode of Unilateral Primary Acute Angle Closure

    PubMed Central

    Lee, Jacky W.Y.; Woo, Tiffany T.Y.; Yau, Gordon S.K.; Yip, Stan; Yick, Doris W.F.; Wong, Jasper; Wong, Raymond L.M.; Wong, Ian Y.H.

    2015-01-01

    Abstract The purpose of this article is to investigate the long-term retinal nerve fiber layer (RNFL) status and determinants of RNFL thinning after an episode of unilateral primary acute angle closure (AAC). This cross-sectional study analyzed the medical records of consecutive patients with a single episode of unilateral AAC from 1999 to 2009 in Hong Kong. The peripapillary RNFL thickness was correlated with age, gender, presenting intraocular pressure (IOP), time to laser iridotomy, time to cataract extraction, follow-up duration, as well as the last IOP, vertical cup-to-disc ratio (CDR), and vision. The fellow uninvolved eye was used as a proxy comparison of RNFL loss in the attack eye. In 40 eligible patients, the mean age was 68.3?±?8.7 years with a male-to-female ratio of 1:7. The mean presenting IOP was 49.2?±?14.0 mm Hg and the time from presentation to laser iridotomy was 6.7?±?6.9 days. Forty percent of subjects received a cataract extraction at 3.2?±?2.9 years after the attack. The last IOP, CDR, and LogMAR vision were 16.0?±?3.8 mm Hg, 0.6?±?0.2, and 0.6?±?0.6 LogMAR units, respectively, at 7.9?±?2.4 years. The RNFL thickness in the attack eye (69.2?±?19.1??m) was 25.2?±?17.9% thinner than the fellow eye (93.0?±?17.8??m) at 7.5?±?2.9 years post-AAC. Using univariate analysis, the last vertical CDR (odds ratio [OR]?=?17.2, P?=?0.049) and LogMAR visual acuity (VA) (OR?=?6.6, P?=?0.03) were the only significant predictors for RNFL thinning whereas none of the other covariates showed significant associations (P?>?0.1). At 7.5 years following unilateral AAC, the RNFL thickness was 25% thinner than the fellow eye. CDR enlargement and poor VA were the only significant predictors for RNFL loss. PMID:25590844

  11. The protective effects of quercetin on the cytotoxicity of atrazine on rat Sertoli-germ cell co-culture.

    PubMed

    Abarikwu, S O; Pant, A B; Farombi, E O

    2012-08-01

    To evaluate the direct effect of atrazine (ATZ) and the protective effect of quercetin (QT) on testicular cells, we used primary cultures of rat Sertoli-germ cells (SGCs). ATZ (232 ?m) up-regulated the mRNA expression of GATA-4, androgen receptor (AR), androgen-binding protein (ABP), steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme (CYP11A1), cyclooxygenase-2 (COX-2) and NF-?appaB (NF-?B) and down-regulated the expression of stem cell factor (SCF) mRNA. There was no change on the mRNA expression of oestrogen receptor-alpha (ER-?). Simultaneous supplementation of QT in the culture normalizes the expression of these genes. The stimulatory action of follicle stimulating hormone (10 ng/mL) on ATZ-induced StAR and CYP11A1 mRNA levels were also prevented by QT. Furthermore, ATZ-stimulatory action on AR mRNA was opposed in a dose-dependent manner in the presence of increasing concentrations of QT (10-50 ?m).The dislodgement of germ cells from the Sertoli cells monolayer and decrease in SGCs viability was prevented by QT. To show whether or not the disrupted interactions of Sertoli and germ cells impaired spermatogenesis, adult male rats exposed in vivo to ATZ (50 mg/kg b.wt) for 1 week had their daily spermatozoa production (DSP) per gram testis lowered by 30%. DSP was significantly increased in the QT(10 mg/kg) + ATZ-treated rats as compared with the ATZ-treated rats. Taken together, ATZ can alter SGCs expression of spermatogenesis- and steroiodogenesis-related genes resulting in a decrease in sperm production in the testis as well as cell viability. QT might block these molecular events-induced by ATZ thereby protecting testicular Sertoli-germ cells from ATZ-induced toxicity. PMID:22372587

  12. Models of germ cell development and their application for toxicity studies.

    PubMed

    Ferreira, Daniel W; Allard, Patrick

    2015-10-01

    Germ cells are unique in their ability to transfer genetic information and traits from generation to generation. As such, the proper development of germ cells and the integrity of their genome are paramount to the health of organisms and the survival of species. Germ cells are also exquisitely sensitive to environmental influences although the testing of germ cell toxicity, especially in females, has proven particularly challenging. In this review, we first describe the remarkable odyssey of germ cells in mammals, with an emphasis on the female germline, from their initial specification early during embryogenesis to the generation of mature gametes in adults. We also describe the current methods used in germ cell toxicity testing and their limitations in examining the complex features of mammalian germ cell development. To bypass these challenges, we propose the use of alternative model systems such as Saccharomyces cerevisiae, Drosophila melanogaster, Caenorhabditis elegans, and in vitro germ cell methods that have distinct advantages over traditional toxicity models. We discuss the benefits and limitations of each approach, their application to germ cell toxicity studies, and the need for computational approaches to maximize the usefulness of these models. Together, the inclusion of these alternative germ cell toxicity models will be invaluable for the examination of stages not easily accessible in mammals as well as the large scale, high-throughput investigation of germ cell toxicity. PMID:25821157

  13. 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

  14. Gradual recruitment and selective clearing generate germ plasm aggregates in the zebrafish embryo.

    PubMed

    Eno, Celeste; Pelegri, Francisco

    2013-01-01

    Determination of primordial germ cells (PGCs) is one of the earliest decisions in animal embryogenesis. In many species, PGCs are determined through maternally-inherited germ plasm ribonucleoparticles (RNPs). In zebrafish, these are transmitted during oogenesis as dispersed RNPs, which after fertilization multimerize and become recruited as large aggregates at furrows for the first and second cell cycles. Here, we show that the number of recruited germ plasm RNPs is halved every cell cycle. We also show that germ plasm RNPs are recruited during the third cell cycle, but only transiently. Our data support a mechanism in which systematic local gathering of germ plasm RNPs during cytokinesis and threshold-dependent clearing contribute to forming germ plasm aggregates with the highest RNP number and germ cell-inducing potential. PMID:24721731

  15. Gradual recruitment and selective clearing generate germ plasm aggregates in the zebrafish embryo

    PubMed Central

    Eno, Celeste; Pelegri, Francisco

    2013-01-01

    Determination of primordial germ cells (PGCs) is one of the earliest decisions in animal embryogenesis. In many species, PGCs are determined through maternally-inherited germ plasm ribonucleoparticles (RNPs). In zebrafish, these are transmitted during oogenesis as dispersed RNPs, which after fertilization multimerize and become recruited as large aggregates at furrows for the first and second cell cycles. Here, we show that the number of recruited germ plasm RNPs is halved every cell cycle. We also show that germ plasm RNPs are recruited during the third cell cycle, but only transiently. Our data support a mechanism in which systematic local gathering of germ plasm RNPs during cytokinesis and threshold-dependent clearing contribute to forming germ plasm aggregates with the highest RNP number and germ cell-inducing potential. PMID:24721731

  16. Successful Treatment of Intracranial Germ Cell Tumor: Report of Two Unusual Cases and Literature Review

    PubMed Central

    Lee, Ju Hyun; Woo, In Sook; Cho, Young Yun; Lee, Won Jik; Han, Deok Jae; Han, Chi Wha; Jung, Yun Hwa

    2015-01-01

    Primary intracranial germ cell tumor (GCT) is a rare tumor that generally occurs due to developmental anomaly. Although intracranial GCT is sensitive to treatment, a high recurrence rate, treatment-related long-term complications and the heterogeneity of this tumor group make treatment complicated. Moreover, because of its location, hydrocephalus and visual field defect, functional disturbance of the pituitary gland can occur and require attention. Treatment primarily relies on chemotherapy and radiation therapy but the management of intracranial GCT remains unsettled, especially in the case of unusual circumstances such as multifocal tumor or nongerminomatous GCT. Here, we present two unusual cases of intracranial GCT: one case with a bifocal intracranial germinoma, and the other with an intracranial choriocarcinoma. Both cases were treated with neoadjuvant chemotherapy followed by reduced-field radiation therapy without significant treatment-related complication. Further, we performed a PubMed search to investigate the appropriate treatment strategy for this unusual subtype of intracranial GCT. PMID:26668575

  17. Mixed Germ Cell Tumour in a Case of Pure Gonadal Dysgenesis (Swyer Syndrome) - A Case Report

    PubMed Central

    M, Venugopal; Mathews, Anitha; James, Francis V

    2016-01-01

    Swyer syndrome or pure gonadal dysgenesis 46, XY is a medical condition associated with 46 XY karyotype and primary amenorrhea in a phenotypic female. In this syndrome, there is an abnormality in testicular differentiation. Patients with disorders in sexual differentiation have an increased risk for development of genital malignancies. A 14-year-old female admitted with abdominal pain was diagnosed to have Swyer syndrome and a pelvic tumor after clinical and laboratory investigations. She underwent surgery, and the histology report revealed a mixed germ cell tumor in a dysgenetic gonad. She recurred three months later and was successfully treated with chemotherapy and a second surgery to remove the differentiated teratoma. The early diagnosis of patients with Swyer syndrome is important because of the increased risk for the development of malignancy. Early surgical treatment is required. Recurrent and metastatic disease respond well to chemotherapy.

  18. Effects of kernel breakage and fermentation on corn germ integrity and oil quality.

    PubMed

    Wang, Hui; Wang, Tong; Johnson, Lawrence A

    2010-09-22

    To investigate the ability of corn germ to withstand the fuel ethanol fermentation process without major damage to germ integrity and germ oil quality, five treatments were designed to explore degerming before fermentation (front-end) and after fermentation (tail-end), and the feasibility of breaking the kernel with minimum shear forces (wet-split). Germ from low-shear (wet-split) tail-end degerming maintained its integrity during the process. The wet-grind pretreatment caused 22% germ damage, and the subsequent fermentation caused 18% additional germ damage. The germ recovered after fermentation showed physical strength similar to that of those isolated by wet means before fermentation. The oils extracted from the tail-end germ fractions had the same low free fatty acid (FFA) content (2%) and similar low peroxide value (2 meq/kg) as those extracted at the front end. The good oil quality of the tail-end germ fraction was attributed to excellent germ integrity. The oil recovered after traditional dry-grind ethanol production was highly deteriorated, with 22% FFAs and 9 meq/kg peroxide value because the germ was broken into small pieces during dry grinding. So long as kernel-breakage or size-reduction pretreatments are conducted to retain intact germs or keep them in large pieces before fermentation, the germ can survive the cooking, starch hydrolysis, and yeast metabolism during the ethanol fermentation process. These findings lay a foundation for developing new degerming strategies where the germ can be isolated during or after fermentation, which could be easily integrated into the conventional dry-grind corn ethanol process. PMID:20804123

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

    PubMed Central

    2012-01-01

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

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

    PubMed

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

    2015-12-01

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

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

    PubMed

    Drevelegas, A; Palladas, P; Scordalaki, A

    2001-01-01

    Germ cell tumors of the mediastinum are histologically identical to those found in the testes and ovaries. Early diagnosis and treatment improve the survival rate. Imaging studies of teratoma demonstrate a rounded, often lobulated heterogeneous mass containing soft tissue elements with fluid and fat attenuation. Calcification is present in 20-43% of cases. Seminomas are large masses of homogeneous soft tissue attenuation. Malignant nonseminomatous germ cell tumors are heterogeneous tumors with irregular borders due to invasion of adjacent structures. CT shows the location and extent of the tumors as well as intrinsic elements including soft tissue, fat, fluid, and calcification. CT is the modality of choice for the diagnostic evaluation of these tumors. MRI reveals masses of heterogeneous signal intensity, is more sensitive in depicting infiltration of the adjacent structures by fat plane obliteration, and is performed as an ancillary study. PMID:11702124

  2. 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

  3. Telomerase activity and telomere length in male germ cells.

    PubMed

    Ozturk, Saffet

    2015-02-01

    Telomeres are located at the outermost ends of all eukaryotic chromosomes and provide for the maintenance of genomic stability and integrity during the life span of organisms. The length of telomeres shortens due to each round of DNA replication, genotoxic insults, and/or reactive oxygen species. To counteract this shortening, certain types of cells, including stem cells, male/female germline cells, granulosa cells, early embryos, and most cancerous cells, express an enzyme known as telomerase, which has the potential of restoring the shortened telomeres. Presence of telomerase activity in the male germ cells ensures maintenance of telomere length at maximum levels during spermatogenesis despite telomere attrition due to DNA replication or other genotoxic factors. In this review, telomerase activity and telomere length in mammalian male germ cells during spermatogenesis are evaluated in detail based on the studies in this field. Also, the relationship between telomerase activity/telomere length and development of male infertility is comprehensively discussed. PMID:25568305

  4. Growing Teratoma Syndrome After Treatment of a Nonseminomatous Germ Cell Tumor: A Case Report and a Review of Literature*

    PubMed Central

    Boukettaya, W.; Hochlaf, M.; Boudagga, Z.; Ezzairi, F.; Chabchoub, I.; Gharbi, O.; Fatma, L. Ben; Sriha, B.; Mokni, M.; Kraim, C.H.; Ahmed, S. Ben

    2013-01-01

    Growing teratoma syndrome is a rare condition among patients with nonseminomatous germ cell tumors who present with enlarging metastatic masses during appropriate systemic chemotherapy and normalized serum markers. Retroperitoneal residual masses are a common finding after chemotherapy for the nonseminomatous tumors of the testis. These might contain mature teratoma, fibrotic tissue, or tumor. Mature teratoma, which is unresponsive to chemotherapy, might result from evolution of a malignant lesion during treatment or it might represent a metastasis from a focus of mature teratoma in the primary testicular tumor. This article reviews a case of a growing teratoma syndrome.

  5. Intraperitoneal germ cell transplantation in the Nile tilapia Oreochromis niloticus.

    PubMed

    Farlora, Rodolfo; Hattori-Ihara, Shoko; Takeuchi, Yukata; Hayashi, Makoto; Octavera, Anna; Alimuddin; Yoshizaki, Goro

    2014-06-01

    Germ cell transplantation offers promising applications in finfish aquaculture and the preservation of endangered species. Here, we describe an intraperitoneal spermatogonia transplantation procedure in the Nile tilapia Oreochromis niloticus. Through histological analysis of early gonad development, we first determined the best suitable stage at which exogenous germ cells should be transplanted into the recipients. For the transplantation procedure, donor testes from a transgenic Nile tilapia strain carrying the medaka ?-actin/enhanced green fluorescent protein (EGFP) gene were subjected to enzymatic dissociation. These testicular cells were then stained with PKH26 and microinjected into the peritoneal cavity of the recipient fish. To confirm colonization of the donor-derived germ cells, the recipient gonads were examined by fluorescent and confocal microscopy. PKH26-labeled cells exhibiting typical spermatogonial morphology were incorporated into the recipient gonads and were not rejected within 22 days posttransplantation. Long-term survival of transgenic donor-derived germ cells was then verified in the gonads of 5-month-old recipients and in the milt and vitelogenic oocytes of 1-year-old recipients, by means of PCR using EGFP-specific primers. EGFP-positive milt from adult male recipients was used to fertilize non-transgenic oocytes and produced transgenic offspring expressing the donor-derived phenotype. These results imply that long-term survival, proliferation, and differentiation of the donor-derived spermatogonia into vitelogenic oocytes and functional spermatozoa are all possible. Upon further improvements in the transplantation efficiency, this intraperitoneal transplantation system could become a valuable tool in the conservation of genetic resources for cichlid species. PMID:24096828

  6. Germ Cell Transport Across the Seminiferous Epithelium During Spermatogenesis

    PubMed Central

    Xiao, Xiang; Mruk, Dolores D.; Wong, Chris K. C.

    2014-01-01

    Transport of germ cells across the seminiferous epithelium is crucial to spermatogenesis. Its disruption causes infertility. Signaling molecules, such as focal adhesion kinase, c-Yes, c-Src, and intercellular adhesion molecules 1 and 2, are involved in these events by regulating actin-based cytoskeleton via their action on actin-regulating proteins, endocytic vesicle-mediated protein trafficking, and adhesion protein complexes. We critically evaluate these findings and provide a hypothetical framework that regulates these events. PMID:24985332

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

    PubMed Central

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

    2013-01-01

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

  8. Oskar predates the evolution of germ plasm in insects.

    PubMed

    Ewen-Campen, Ben; Srouji, John R; Schwager, Evelyn E; Extavour, Cassandra G

    2012-12-01

    oskar is the only gene in the animal kingdom necessary and sufficient for specifying functional germ cells. However, oskar has only been identified in holometabolous ("higher") insects that specify their germline using specialized cytoplasm called germ plasm. Here we show that oskar evolved before the divergence of higher insects and provide evidence that its germline role is a recent evolutionary innovation. We identify an oskar ortholog in a basally branching insect, the cricket Gryllus bimaculatus. In contrast to Drosophila oskar, Gb-oskar is not required for germ cell formation or axial patterning. Instead, Gb-oskar is expressed in neuroblasts of the brain and CNS and is required for neural development. Taken together with reports of a neural role for Drosophila oskar, our data demonstrate that oskar arose nearly 50 million years earlier in insect evolution than previously thought, where it may have played an ancestral neural role, and was co-opted to its well-known essential germline role in holometabolous insects. PMID:23122849

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-05-01

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

  11. Pristane-induced autoimmunity in germ-free mice.

    PubMed

    Mizutani, Akiei; Shaheen, Victoria M; Yoshida, Hideo; Akaogi, Jun; Kuroda, Yoshiki; Nacionales, Dina C; Yamasaki, Yoshioki; Hirakata, Michito; Ono, Nobutaka; Reeves, Westley H; Satoh, Minoru

    2005-02-01

    Hypergammaglobulinemia and autoantibodies are reduced in pristane-treated specific pathogen-free mice vs. conventionally housed controls, consistent with the role of microbial stimulation in this model. To determine whether microbial stimulation is required, BALB/c mice housed under germ-free conditions were treated i.p. with sterile PBS or pristane and examined 6 months later. As in conventional mice, pristane-treated germ-free mice developed peritoneal granulomas and hypergammaglobulinemia with increased IgG2a/IgG1 ratios. LPS stimulation induced more IL-6, IL-12, and TNF-alpha, and anti-CD3 induced more IFN-gamma and IL-4 by peritoneal cells from pristane-treated mice vs. control. Anti-nRNP/Sm and -Su autoantibodies were found in 40% and 43%, respectively, of pristane-treated germ-free mice by immunoprecipitation. Thus, bacterial stimulation was not required for lupus autoantibodies, peritoneal granuloma formation, hypergammaglobulinemia, or cytokine overproduction. Although microbial stimulation acts synergistically with pristane, these results clearly indicate that pristane does not act merely by increasing exposure to microbial products such as LPS. PMID:15639644

  12. PGC-Enriched miRNAs Control Germ Cell Development

    PubMed Central

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

    2015-01-01

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

  13. Germ cell development in the Honeybee (Apis mellifera); Vasa and Nanos expression

    PubMed Central

    Dearden, Peter K

    2006-01-01

    Background Studies of specification of germ-cells in insect embryos has indicated that in many taxa the germ cells form early in development, and their formation is associated with pole plasm, germ plasm or an organelle called the oosome. None of these morphological features associated with germ cell formation have been identified in the Honeybee Apis mellifera. In this study I report the cloning and expression analysis of Honeybee homologues of vasa and nanos, germ cell markers in insects and other animals. Results Apis vasa and nanos RNAs are present in early honeybee embryos, but the RNAs clear rapidly, without any cells expressing these germ cell markers past stage 2. These genes are then only expressed in a line of cells in the abdomen from stage 9 onwards. These cells are the developing germ cells that are moved dorsally by dorsal closure and are placed in the genital ridge. Conclusion This study of the expression of germ cell markers in the honeybee implies that in this species either germ cells are formed by an inductive event, late in embryogenesis, or they are formed early in development in the absence of vasa and nanos expression. This contrasts with germ cell development in other members of the Hymenoptera, Diptera and Lepidoptera. PMID:16503992

  14. Recent advances in the derivation of germ cells from the embryonic stem cells.

    PubMed

    Hua, Jinlian; Sidhu, Kuldip

    2008-06-01

    In recent years, considerable progress has been made in the establishment and differentiation of human embryonic stem (ES) cell lines. The primordial germ cells (PGCs) and embryonic germ (EG) cells derived from them share many of their properties with ES cells. ES cell lines have now been derived from different stages of germ cell development and they have differentiated into gametes and shown embryonic development in mice, including the production of live pups. Conversely, germ cells can also be derived from ES cells. It has been demonstrated that murine (m) ES cells can differentiate into PGCs and subsequently into early gametes (oocytes and sperms) and blastocysts. Recently, immature sperm cells derived from mES cells in culture have produced live offspring. Preliminary research has indicated that human (h) ES cells probably have the potential to differentiate into germ cells. Adult stem cells have been reported to differentiate into mature germ cells in vitro. Therefore, stem cells may offer a valuable in vitro model for the investigation of germ cell development and the early stages of human gametogenesis, including epigenetic modifications of the germ line. This review discusses recent developments in the derivation and specification of mammalian germ cells from ES cells and describes some of the mechanisms of germ cell development. PMID:18576912

  15. BMP signaling is required for the generation of primordial germ cells in an insect.

    PubMed

    Donoughe, Seth; Nakamura, Taro; Ewen-Campen, Ben; Green, Delbert A; Henderson, Lory; Extavour, Cassandra G

    2014-03-18

    Two modes of germ cell formation are known in animals. Specification through maternally inherited germ plasm occurs in many well-characterized model organisms, but most animals lack germ plasm by morphological and functional criteria. The only known alternative mechanism is induction, experimentally described only in mice, which specify germ cells through bone morphogenetic protein (BMP) signal-mediated induction of a subpopulation of mesodermal cells. Until this report, no experimental evidence of an inductive germ cell signal for specification has been available outside of vertebrates. Here we provide functional genetic experimental evidence consistent with a role for BMP signaling in germ cell formation in a basally branching insect. We show that primordial germ cells of the cricket Gryllus bimaculatus transduce BMP signals and require BMP pathway activity for their formation. Moreover, increased BMP activity leads to ectopic and supernumerary germ cells. Given the commonality of BMP signaling in mouse and cricket germ cell induction, we suggest that BMP-based germ cell formation may be a shared ancestral mechanism in animals. PMID:24591634

  16. BMP signaling is required for the generation of primordial germ cells in an insect

    PubMed Central

    Donoughe, Seth; Nakamura, Taro; Ewen-Campen, Ben; Green, Delbert A.; Henderson, Lory; Extavour, Cassandra G.

    2014-01-01

    Two modes of germ cell formation are known in animals. Specification through maternally inherited germ plasm occurs in many well-characterized model organisms, but most animals lack germ plasm by morphological and functional criteria. The only known alternative mechanism is induction, experimentally described only in mice, which specify germ cells through bone morphogenetic protein (BMP) signal-mediated induction of a subpopulation of mesodermal cells. Until this report, no experimental evidence of an inductive germ cell signal for specification has been available outside of vertebrates. Here we provide functional genetic experimental evidence consistent with a role for BMP signaling in germ cell formation in a basally branching insect. We show that primordial germ cells of the cricket Gryllus bimaculatus transduce BMP signals and require BMP pathway activity for their formation. Moreover, increased BMP activity leads to ectopic and supernumerary germ cells. Given the commonality of BMP signaling in mouse and cricket germ cell induction, we suggest that BMP-based germ cell formation may be a shared ancestral mechanism in animals. PMID:24591634

  17. Chemical analysis of melanin pigments in feather germs of Japanese quail Bh (black at hatch) mutants.

    PubMed

    Shiojiri, N; Niwa, T; Wakamatsu, K; Ito, S; Nakamura, A

    1999-08-01

    Bh (black at hatch) is a mutation of Japanese quails which causes darkening or lightening of the plumage in heterozygotes or homozygotes, respectively. We chemically analyzed melanin pigments in feather germs of Bh mutant embryos and in feathers of adult animals. Dark brown dorsal feathers of wild-type adult animals had white barrings, but heterozygous ones lacked clear barrings. The feathers of wild-type and heterozygote animals contained both eumelanins and pheomelanins, the latter being more pheomelanic. On the dorsal skin of 10-day old wild-type embryos, longitudinal stripes from black and yellow rows of feather germs developed; two or three longitudinal rows of black feather germs and then two or three rows of yellow feather germs next to the short central feather germs. Heterozygous embryos appeared black in plumage pigmentation, due to the presence of 'gray' feather germs in rows of dorsal feather germs that corresponded to yellow rows in wild-type embryos. Homozygous dorsal feather germs did not develop the black and yellow longitudinal stripes, but were brown. Chemical analysis showed that embryos of each genotype contained both eumelanins and pheomelanins in the feather germs; however, the eumelanin content in homozygous feather germs was very low. These results suggest that the Bh mutation causes pheomelanic changes in feathers of quails. PMID:10454294

  18. Everolimus and Letrozole in Treating Patients With Recurrent Hormone Receptor Positive Ovarian, Fallopian Tube, or Primary Peritoneal Cavity Cancer

    ClinicalTrials.gov

    2015-10-13

    Malignant Ovarian Mixed Epithelial Tumor; Ovarian Endometrioid Adenocarcinoma; Ovarian Serous Cystadenocarcinoma; Ovarian Serous Surface Papillary Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Ovarian Germ Cell Tumor; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Ovarian Carcinoma

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  1. Environmental Susceptibility of the Sperm Epigenome During Windows of Male Germ Cell Development.

    PubMed

    Wu, Haotian; Hauser, Russ; Krawetz, Stephen A; Pilsner, J Richard

    2015-12-01

    Male germ cells require multiple epigenetic reprogramming events during their lifespan to achieve reproductive capacity. An emerging body of compelling data demonstrates that environmental exposures can be embodied within the developing male germ cell as epigenetic marks. In turn, these epigenetic marks can impart information at fertilization to affect the trajectory of offspring health and development. While it is recognized that in utero epigenetic reprogramming of male germ cells is a particularly susceptible window to environmental exposures, other such windows exist during germ cell development. The objective of this review is to discuss epigenetic reprogramming events during male germ cell development and to provide supporting evidence from animal and human studies that during specific periods of development, germ cells are susceptible to environmentally induced epigenetic errors. Moving forward, the nascent field of sperm epigenetics research is likely to advance our understanding of paternal environmental determinants of offspring health and development. PMID:26362467

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

    PubMed Central

    Johnson, Andrew D.; Alberio, Ramiro

    2015-01-01

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

  3. Secondary ion emission from polymethacrylate LB-layers under 0.5 11 keV atomic and molecular primary ion bombardment

    NASA Astrophysics Data System (ADS)

    Stapel, D.; Thiemann, M.; Benninghoven, A.

    2000-02-01

    Secondary ion yields Y(X iq) increase considerably when changing from atomic to molecular primary ions, whereas the parallel increase in the corresponding damage cross sections ?(X iq) is much smaller. This results in a net increase of ion formation efficiencies E(X iq)= Y/ ?. For a more detailed understanding of the complex sputtering and ion formation processes, in particular for molecular primary ion bombardment, the secondary ion emission of well-defined polymethacrylate LB mono- and multilayers on Ag was investigated. For characteristic secondary ions X iq emitted from these overlayers Y(X iq) and ?(X iq) for 11 keV Ne +, Ar +, Xe +, O 2+, SF 5+, C 7H 7+, C 10H 8+, C 6F 6+ and C 10F 8+ bombardment were determined and compared. The influence of primary ion energy was investigated in the energy range between 0.5 and 10 keV for Xe + and SF 5+ bombardment. For multilayers we found yield increases up to nearly a factor of 1000, when changing from Ne + to SF 5+ bombardment. We found a more pronounced yield and efficiency enhancement for multi than for monolayer coverages, a saturation of Y, ? and E enhancement for primary ions made of more than 6 heavy constituents at constant primary ion energy, no chemical effect on the secondary ion yields under static SIMS conditions (SF 5+ / C 7H 7+ e.g.), and a pronounced decrease in secondary ion yields and secondary ion formation efficiencies for SF 5+ primary ions with impact energies below 2 keV.

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

    NASA Astrophysics Data System (ADS)

    Ergazaki, Marida; Saltapida, Konstantina; Zogza, Vassiliki

    2010-11-01

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

  5. Seasonal spermatogenic cycle and morphology of germ cells in the viviparous lizard Mabuya brachypoda (Squamata, Scincidae).

    PubMed

    Hernández-Franyutti, Arlette; Uribe, Mari Carmen

    2012-11-01

    We describe seasonal variations of the histology of the seminiferous tubules and efferent ducts of the tropical, viviparous skink, Mabuya brachypoda, throughout the year. The specimens were collected monthly, in Nacajuca, Tabasco state, Mexico. The results revealed strong annual variations in testicular volume, stages of the germ cells, and diameter and height of the epithelia of seminiferous tubules and efferent ducts. Recrudescence was detected from November to December, when initial mitotic activity of spermatogonia in the seminiferous tubules were observed, coinciding with the decrease of temperature, photoperiod and rainy season. From January to February, early spermatogenesis continued and early primary and secondary spermatocytes were developing within the seminiferous epithelium. From March through April, numerous spermatids in metamorphosis were observed. Spermiogenesis was completed from May through July, which coincided with an increase in temperature, photoperiod, and rainfall. Regression occurred from August through September when testicular volume and spermatogenic activity decreased. During this time, the seminiferous epithelium decreased in thickness, and germ cell recruitment ceased, only Sertoli cells and spermatogonia were present in the epithelium. Throughout testicular regression spermatocytes and spermatids disappeared and the presence of cellular debris, and scattered spermatozoa were observed in the lumen. The regressed testes presented the total suspension of spermatogenesis. During October, the seminiferous tubules contained only spermatogonia and Sertoli cells, and the size of the lumen was reduced, giving the appearance that it was occluded. In concert with testis development, the efferent ducts were packed with spermatozoa from May through August. The epididymis was devoid of spermatozoa by September. M. brachypoda exhibited a prenuptial pattern, in which spermatogenesis preceded the mating season. The seasonal cycle variations of spermatogenesis in M. brachypoda are the result of a single extended spermiation event, which is characteristic of reptilian species. PMID:22806886

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

    PubMed

    Kim, Joo-Young; Park, Jeonghoon

    2015-05-01

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

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

    PubMed Central

    Park, Jeonghoon

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2003-01-01

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

  9. 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

  10. Sirt1 deficiency attenuates spermatogenesis and germ cell function.

    PubMed

    Coussens, Matthew; Maresh, John G; Yanagimachi, Ryuzo; Maeda, Gregg; Allsopp, Richard

    2008-01-01

    In mammals, Sirt1, a member of the sirtuin family of proteins, functions as a nicotinamide adenine dinucleotide-dependent protein deactylase, and has important physiological roles, including the regulation of glucose metabolism, cell survival, and mitochondrial respiration. The initial investigations of Sirt1 deficient mice have revealed a phenotype that includes a reduced lifespan, small size, and an increased frequency of abnormal sperm. We have now performed a detailed analysis of the molecular and functional effects of Sirt1 deficiency in the germ line of Sirt1 knock-out (-/-) mice. We find that Sirt1 deficiency markedly attenuates spermatogenesis, but not oogenesis. Numbers of mature sperm and spermatogenic precursors, as early as d15.5 of development, are significantly reduced ( approximately 2-10-fold less; Pgerm cells, we compared the efficiency of generating embryos and viable offspring in in vitro fertilization (IVF) experiments using gametes from Sirt1-/- and sibling Sirt1+/- mice. While viable animals were derived in both Sirt1-/- X wild type and Sirt1-/- X Sirt1-/- crosses, the efficiency of producing both 2-cell zygotes and viable offspring was diminished when IVF was performed with Sirt1-/- sperm and/or oocytes. Together, these data support an important role for Sirt1 in spermatogenesis, including spermatogenic stem cells, as well as germ cell function. PMID:18270565

  11. TLR signalling can modify the mineralization of tooth germ.

    PubMed

    Papp, Tamas; Hollo, Krisztina; Meszar-Katona, Eva; Nagy, Zoltan; Polyak, Angela; Miko, Edit; Bai, Peter; Felszeghy, Szabolcs

    2016-05-01

    Objective The aim of this work is to investigate the possible role of Toll-like receptor 4 (TLR4) during the development of mouse tooth germ. TLR4 is well known to inhibit mineralization and cause inflammation in mature odontoblasts and dental pulp cells. However, unlike these pathological functions of TLR4, little is known about the developmental function(s) of TLR4 during tooth development. Materials and methods TLR4 expression was studied via Western blot in developing lower mouse incisors from E13.5 to E18.5. To generate functional data about the effects of TLR4, a specific agonist (LPS) was applied to the medium of in vitro tooth germ cultures, followed by Western blot, histochemical staining, ELISA assay, in situ hybridization and RT-qPCR. Results Increased accumulation of biotin-labelled LPS was detected in the enamel organ and in preodontoblasts. LPS treatment induced degradation of the inhibitor molecule (IκB) of the NF-κB signalling pathway. However, no morphological alterations were detected in cultured tissue after LPS addition at the applied dosage. Activation of TLR4 inhibited the mineralization of enamel and dentin, as demonstrated by alizarin red staining and as decreased levels of collagen type X. mRNA expression of ameloblastin was elevated after LPS administration. Conclusion These results demonstrate that TLR4 may decrease the mineralization of hard tissues of the tooth germ and may trigger the maturation of ameloblasts; it can give valuable information to understand better congenital tooth abnormalities. PMID:26763602

  12. Germ cell tumors masquerading as central nervous system sarcoidosis.

    PubMed

    Peeples, D M; Stern, B J; Jiji, V; Sahni, K S

    1991-05-01

    The diagnosis of central nervous system sarcoidosis is uncertain without typical multisystem involvement. We describe two patients with isolated central nervous system mass lesions whose biopsy results were consistent with sarcoidosis. After a progressive clinical course, they were found to have diencephalic germinomas. Germ cell tumors, in particular, should be considered in the differential diagnosis of central nervous system sarcoidosis as they are potentially treatable, occur in intracranial locations favored by sarcoidosis mass lesions, and may be surrounded by granulomatous inflammation that can be mistaken for the noncaseating granulomas of sarcoidosis. PMID:1850595

  13. LINEing germ and embryonic stem cells’ silencing of retrotransposons

    PubMed Central

    Ishiuchi, Takashi; Torres-Padilla, Maria-Elena

    2014-01-01

    Almost half of our genome is occupied by transposable elements. Although most of them are inactive, one type of non-long terminal repeat (LTR) retrotransposon, long interspersed nuclear element 1 (LINE1), is capable of retrotransposition. Two studies in this issue, Pezic and colleagues (pp. 1410–1428) and Castro-Diaz and colleagues (pp. 1397–1409), provide novel insight into the regulation of LINE1s in human embryonic stem cells and mouse germ cells and shed new light on the conservation of complex mechanisms to ensure silencing of transposable elements in mammals. PMID:24990961

  14. Transgene-mediated cosuppression in the C. elegans germ line

    PubMed Central

    Dernburg, Abby F.; Zalevsky, Jonathan; Colaiácovo, Mónica P.; Villeneuve, Anne M.

    2000-01-01

    Functional silencing of chromosomal loci can be induced by transgenes (cosuppression) or by introduction of double-stranded RNA (RNAi). Here, we demonstrate the generality of and define rules for a transgene-mediated cosuppression phenomenon in the Caenorhabditis elegans germ line. Functional repression is not a consequence of persistent physical association between transgenes and endogenous genes or of mutations in affected genes. The cosuppression mechanism likely involves an RNA mediator that defines its target specificity, reminiscent of RNAi. Cosuppression is strongly abrogated in rde-2 and mut-7 mutants, but is not blocked in an rde-1 mutant, indicating that cosuppression and RNAi have overlapping but distinct genetic requirements. PMID:10887151

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

    PubMed

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

    2015-05-01

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

  16. Outcomes following retroperitoneal lymph node dissection in postchemotherapy residual masses in advanced testicular germ cell tumors

    PubMed Central

    Singh, Prabhjot; Yadav, Siddharth; Mahapatra, Sanjay; Seth, Amlesh

    2016-01-01

    Introduction: We aimed to study the outcomes of retroperitoneal lymph node dissection (RPLND) in postchemotherapy residual masses in advanced testicular germ cell tumor (GCT) in the Indian population. Patients and Methods: We retrospectively analyzed 35 patients who underwent postchemotherapy RPLND at our institute after primary (29 patients) or salvage (6 patients) chemotherapy over a period of 9 years (June 2003 to July 2012). Results: The mean age of our patients was 26.8 years. 18 (51.42%) presented with primary tumor in the right testis and 3 (8.51%) had bilateral tumors. Mixed GCT was the most common histology among 19 (54.3%) patients. 14 (40%) patients had the residual mass in para-aortic location, which was the most common site. 14 (40%) patients required an adjunctive procedure, most commonly nephrectomy which was required in 9 out of 14 (25.7%). We recorded 25 complications, mostly Clavien-Dindo grade II. Histopathology of residual mass was necrosis in 17 (48.57%), teratoma in 12 (34.28%), and viable tumor in 6 (17.14%) patients. Conclusion: Nearly half of the patients had either teratoma or viable tumor, thus justifying the surgical resection of postchemotherapy residual mass. Although nearly half of the patients had complications, they were adequately managed and there was no mortality. Thus, postchemotherapy RPLND can be a useful procedure in multimodality approach to GCT in carefully selected patients. PMID:26941493

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

    PubMed

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

    2015-09-20

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

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

    PubMed

    Živković, Daniel; Tellier, Aurélien

    2012-11-01

    Continuous progress in empirical population genetics based on the whole-genome polymorphism data requires the theoretical analysis of refined models in order to interpret the evolutionary history of populations with adequate accuracy. Recent studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life-history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. Within this study, we investigate the combined effect of germ banking and time-varying population size on the neutral coalescent and particularly derive the allele frequency spectrum under some simplifying assumptions. We then perform an ABC analysis using two simple demographic scenarios-a population expansion and an instantaneous decline. We demonstrate the appreciable influence of seed banks on the estimation of demographic parameters depending on the germination rate with biases scaled by the square of the germination rate. In the more complex case of a population bottleneck, which comprises an instantaneous decline and an expansion phase, ignoring information on the germination rate denies reliable estimates of the bottleneck parameters via the allelic spectrum. In particular, when seeds remain in the bank over several generations, recent expansions may remain invisible in the frequency spectrum, whereas ancient declines leave signatures much longer than in the absence of seed bank. PMID:23050602

  19. Chlorambucil effectively induces deletion mutations in mouse germ cells

    SciTech Connect

    Russell, L.B.; Hunsicker, P.R.; Cacheiro, N.L.A.; Bangham, J.W.; Russell, W.L.; Shelby, M.D. )

    1989-05-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to data in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with {approx} 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germline mutations at highest frequencies, chlorambucil may be the mutagen of choice.

  20. Genetic Control of Male Germ Unit Organization in Arabidopsis1

    PubMed Central

    Lalanne, Eric; Twell, David

    2002-01-01

    In flowering plants, the vegetative nucleus and the two sperm cells are proposed to form a functional assemblage, the male germ unit (MGU). Here, we describe the developmental pathway of MGU assembly in Arabidopsis and report two classes of mutations that affect the integrity and/or the positioning of the MGU in the mature pollen grain. In germ unit malformed (gum) mutants, the vegetative nucleus is positioned adjacent to the pollen grain wall, separate from the two sperm cells, whereas in MGU displaced (mud) mutants, the intact MGU is displaced to the pollen grain wall. mud and gum mutants correspond to male-specific gametophytic mutations that also reduce pollen fitness. Genetic mapping showed that the gum1 and gum2 mutations are genetically linked, possibly allelic, whereas the mud1 and mud2 mutations correspond to two unlinked loci mapping on different chromosomes. The hierarchical relationship between mud and gum mutations was investigated by phenotypic analysis of double mutants. gum1 appeared to act earlier than mud1 and mud2, affecting initial MGU assembly and its stability during pollen maturation. In contrast, mud1 and mud2 mutations appear to act only on MGU positioning during final maturation. From in planta analyses of pollen germination in mud and gum mutants, we conclude that the initial proximity and positioning of MGU components is not required for their entrance into the pollen tube, but the efficiency of MGU translocation is reduced. PMID:12068125

  1. 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

  2. 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…

  3. Next generation organelles: structure and role of germ granules in the germline.

    PubMed

    Gao, Ming; Arkov, Alexey L

    2013-08-01

    Germ cells belong to a unique class of stem cells that gives rise to eggs and sperm, and ultimately to an entire organism after gamete fusion. In many organisms, germ cells contain electron-dense structures that are also known as nuage or germ granules. Although germ granules were discovered more than 100 years ago, their composition, structure, assembly, and function are not fully understood. Germ granules contain non-coding RNAs, mRNAs, and proteins required for germline development. Here we review recent studies that highlight the importance of several protein families in germ granule assembly and function, including germ granule inducers, which initiate the granule formation, and downstream components, such as RNA helicases and Tudor domain-Piwi protein-piRNA complexes. Assembly of these components into one granule is likely to result in a highly efficient molecular machine that ensures translational control and protects germline DNA from mutations caused by mobile genetic elements. Furthermore, recent studies have shown that different somatic cells, including stem cells and neurons, produce germ granule components that play a crucial role in stem cell maintenance and memory formation, indicating a much more diverse functional repertoire for these organelles than previously thought. PMID:23011946

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

    EPA Science Inventory

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

  5. SYNAPTONEMAL COMPLEX DAMAGE AS A MEASURE OF CHEMICAL MUTAGEN EFFECTS ON MAMMALIAN GERM CELLS

    EPA Science Inventory

    As heritable chromosome anomalies are implicated in a variety of human disabilities, their induction in germ cells by environmental chemicals is viewed as a threat to health. Synaptonemal complex (SC) analysis is a novel approach for the detection of germ-line chromosomal damage....

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

    ERIC Educational Resources Information Center

    Ergazaki, Marida; Saltapida, Konstantina; Zogza, Vassiliki

    2010-01-01

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

  7. 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...

  8. GENETIC ANOMALIES IN MAMMALIAN GERM CELLS AND THEIR SIGNIFICANCE FOR HUMAN REPRODUCTIVE AND DEVELOPMENTAL RISK

    EPA Science Inventory

    The induction of heritable mutations in germ cells represents a potential health concern. his paper will highlight several themes in the area of germ-cell mutagenesis and their implications in reproductive and developmental risk. dditionally, factors that influence the yield of g...

  9. 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).

  10. Oil separation from foam fractions of enzymatically treated wet milled corn germ dispersions

    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, if an economical method of separating it can be developed. Oil was separated from corn germ by aqueous enzymatic extraction (AEE). Batches of wet- milled corn germ in water were...

  11. Are germ cell tumors part of the Li-Fraumeni cancer family syndrome?

    PubMed

    Hartley, A L; Birch, J M; Kelsey, A M; Marsden, H B; Harris, M; Teare, M D

    1989-10-15

    The occurrence of six cases of germ cell tumors, five testicular and one ovarian, in relatives of children with bone or soft tissue sarcomas is described. It is proposed that germ cell tumors may be an uncommon manifestation of the genetic predisposition to cancer that exists in the Li-Fraumeni cancer family syndrome. PMID:2790757

  12. In vitro germ cell differentiation from cynomolgus monkey embryonic stem cells.

    TOXLINE Toxicology Bibliographic Information

    Yamauchi K; Hasegawa K; Chuma S; Nakatsuji N; Suemori H

    2009-01-01

    BACKGROUND: Mouse embryonic stem (ES) cells can differentiate into female and male germ cells in vitro. Primate ES cells can also differentiate into immature germ cells in vitro. However, little is known about the differentiation markers and culture conditions for in vitro germ cell differentiation from ES cells in primates. Monkey ES cells are thus considered to be a useful model to study primate gametogenesis in vitro. Therefore, in order to obtain further information on germ cell differentiation from primate ES cells, this study examined the ability of cynomolgus monkey ES cells to differentiate into germ cells in vitro.METHODS AND FINDINGS: To explore the differentiation markers for detecting germ cells differentiated from ES cells, the expression of various germ cell marker genes was examined in tissues and ES cells of the cynomolgus monkey (Macaca fascicularis). VASA is a valuable gene for the detection of germ cells differentiated from ES cells. An increase of VASA expression was observed when differentiation was induced in ES cells via embryoid body (EB) formation. In addition, the expression of other germ cell markers, such as NANOS and PIWIL1 genes, was also up-regulated as the EB differentiation progressed. Immunocytochemistry identified the cells expressing stage-specific embryonic antigen (SSEA) 1, OCT-4, and VASA proteins in the EBs. These cells were detected in the peripheral region of the EBs as specific cell populations, such as SSEA1-positive, OCT-4-positive cells, OCT-4-positive, VASA-positive cells, and OCT-4-negative, VASA-positive cells. Thereafter, the effect of mouse gonadal cell-conditioned medium and growth factors on germ cell differentiation from monkey ES cells was examined, and this revealed that the addition of BMP4 to differentiating ES cells increased the expression of SCP1, a meiotic marker gene.CONCLUSION: VASA is a valuable gene for the detection of germ cells differentiated from ES cells in monkeys, and the identification and characterization of germ cells derived from ES cells are possible by using reported germ cell markers in vivo, including SSEA1, OCT-4, and VASA, in vitro as well as in vivo. These findings are thus considered to help elucidate the germ cell developmental process in primates.

  13. 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

  14. Bisphenol A exposure inhibits germ cell nest breakdown by reducing apoptosis in cultured neonatal mouse ovaries.

    PubMed

    Zhou, Changqing; Wang, Wei; Peretz, Jackye; Flaws, Jodi A

    2015-11-01

    Bisphenol A is a known endocrine disrupting chemical and reproductive toxicant. Previous studies indicate that in utero BPA exposure increases the percentage of germ cells in nests and decreases the percentage of primordial follicles. However, the mechanism by which BPA affects germ cell nest breakdown is unknown. Thus, we hypothesized that BPA inhibits germ cell nest breakdown by interfering with oxidative stress and apoptosis pathways. To test our hypothesis, ovaries from newborn mice were collected and cultured with vehicle (dimethyl sulfoxide, DMSO) or different doses of BPA (0.1, 1, 5, and 10?g/mL). Ovaries then were subjected to histological evaluation of germ cell nests and primordial follicles or to measurements of factors that regulate oxidative stress and apoptosis. Our results indicate that in vitro BPA exposure significantly inhibits germ cell nest breakdown by altering the expression of key ovarian apoptotic genes, but not by interfering with the oxidative stress pathway. PMID:26049153

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

    PubMed

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

    2016-01-01

    The timing and biological events associated with germ cell specification in chickens have not been determined yet. In this study, we report the origin of primordial germ cells (PGCs) and germ plasm dynamics through investigation of the expression of the chicken homolog of deleted in azoospermia-like (cDAZL) gene during germ cell specification. Asymmetric localization of germ plasm in the center of oocytes from preovulatory follicle stages leads to PGCs being formed in the center. During cleavage stages, DAZL expression pattern changes from a subcellular localization to a diffuse form before and after zygotic genome activation. Meanwhile, PGCs exhibit transcriptional active status during their specification. In addition, knockdown studies of cDAZL, which result in reduced proliferation, aberrant gene expression profiles, and PGC apoptosis in vitro, suggest its possible roles for PGC formation in chicken. In conclusion, DAZL expression reveals formation and initial positioning of PGCs in chickens. PMID:26414995

  16. Precious cargo: regulation of sex-specific germ cell development in mice.

    PubMed

    Bowles, J; Koopman, P

    2013-01-01

    Although mammalian sex determination is normally specified genetically by an XX or XY chromosome complement, germ cells develop as sperm or oocytes in response to molecular cues provided by the gonadal somatic cells. In an ovary, germ cells enter meiosis during fetal life, thereby committing to oogenesis. In a testis, germ cells do not enter meiosis until after birth, at puberty. Recent findings indicate that, in mice, the sex-specific timing of entry into meiosis is governed by the balance between 2 secreted signalling molecules, retinoic acid (RA), which promotes entry into meiosis, and fibroblast growth factor 9 (FGF9), which counteracts RA. The combined action of these 2 molecular regulators provides a safety mechanism to guard against germ cell dysregulation that can lead to infertility or germ cell cancers. PMID:22947624

  17. 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.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  19. PUMA regulates germ cell loss and primordial follicle endowment in mice.

    PubMed

    Myers, Michelle; Morgan, F Hamish; Liew, Seng H; Zerafa, Nadeen; Gamage, Thilini Upeksha; Sarraj, Mai; Cook, Michele; Kapic, Ileana; Sutherland, Antony; Scott, Clare L; Strasser, Andreas; Findlay, Jock K; Kerr, Jeffrey B; Hutt, Karla J

    2014-08-01

    The number of primordial follicles initially established within the ovary is influenced by the extent of germ cell death during foetal ovarian development, but the mechanisms that mediate this death have not been fully uncovered. In this study, we identified BBC3 (PUMA) (p53 upregulated modulator of apoptosis, also known as BCL2-binding component 3), a pro-apoptotic BH3-only protein belonging to the BCL2 family, as a critical determinant of the number of germ cells during ovarian development. Targeted disruption of the Bbc3 gene revealed a significant increase in the number of germ cells as early as embryonic day 13.5. The number of germ cells remained elevated in Bbc3(-/-) female mice compared with WT female mice throughout the remainder of embryonic and early postnatal life, resulting in a 1.9-fold increase in the number of primordial follicles in the ovary on postnatal day 10. The increase in the number of germ cells observed in the ovaries of Bbc3(-/-) mice could not be attributed to the altered proliferative activity of germ cells within the ovaries. Furthermore, BBC3 was found to be not required for the massive germ cell loss that occurs during germ cell nest breakdown. Our data indicate that BBC3 is a critical regulator of germ cell death that acts during the migratory phase of oogenesis or very soon after the arrival of germ cells in the gonad and that BBC3-mediated cell death limits the number of primordial follicles established in the initial ovarian reserve. PMID:24859845

  20. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Addition of Wheat Germ Oil to a Liquid Larval Diet for Rearing Improved Quality Oriental Fruit Flies (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat germ oil was added into a low waste larval liquid diet for rearing Bactrocera dorsalis (Hendel) to optimize the fruit fly performance. Various concentrations of 0.04, 0.07, 0.15, 0.30, and 0.66 % of wheat germ oil were evaluated. Results showed that the addition of wheat germ oil did not affec...

  3. Overexpression of peroxisomal testis-specific 1 protein induces germ cell apoptosis and leads to infertility in male mice

    PubMed Central

    Kaczmarek, Karina; Studencka, Maja; Meinhardt, Andreas; Wieczerzak, Krzysztof; Thoms, Sven; Engel, Wolfgang; Grzmil, Pawel

    2011-01-01

    ?Peroxisomal testis-specific 1 gene (Pxt1) is the only male germ cell–specific gene that encodes a peroxisomal protein known to date. To elucidate the role of Pxt1 in spermatogenesis, we generated transgenic mice expressing a c-MYC-PXT1 fusion protein under the control of the PGK2 promoter. Overexpression of Pxt1 resulted in induction of male germ cells’ apoptosis mainly in primary spermatocytes, finally leading to male infertility. This prompted us to analyze the proapoptotic character of mouse PXT1, which harbors a BH3-like domain in the N-terminal part. In different cell lines, the overexpression of PXT1 also resulted in a dramatic increase of apoptosis, whereas the deletion of the BH3-like domain significantly reduced cell death events, thereby confirming that the domain is functional and essential for the proapoptotic activity of PXT1. Moreover, we demonstrated that PXT1 interacts with apoptosis regulator BAT3, which, if overexpressed, can protect cells from the PXT1-induced apoptosis. The PXT1-BAT3 association leads to PXT1 relocation from the cytoplasm to the nucleus. In summary, we demonstrated that PXT1 induces apoptosis via the BH3-like domain and that this process is inhibited by BAT3. PMID:21460186

  4. Oct4 is required for primordial germ cell survival

    PubMed Central

    Kehler, James; Tolkunova, Elena; Koschorz, Birgit; Pesce, Maurizio; Gentile, Luca; Boiani, Michele; Lomelí, Hilda; Nagy, Andras; McLaughlin, K John; Schöler, Hans R; Tomilin, Alexey

    2004-01-01

    Previous studies have shown that Oct4 has an essential role in maintaining pluripotency of cells of the inner cell mass (ICM) and embryonic stem cells. However, Oct4 null homozygous embryos die around the time of implantation, thus precluding further analysis of gene function during development. We have used the conditional Cre/loxP gene targeting strategy to assess Oct4 function in primordial germ cells (PGCs). Loss of Oct4 function leads to apoptosis of PGCs rather than to differentiation into a trophectodermal lineage, as has been described for Oct4-deficient ICM cells. These new results suggest a previously unknown function of Oct4 in maintaining viability of mammalian germline. PMID:15486564

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

    PubMed

    Wainwright, Milton; Alharbi, Sulaiman Ali

    2011-10-01

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

  6. [Demonstration of a protocol for obtaining germ-free chickens].

    PubMed

    Le Bars, J

    1976-01-01

    A simple and reliable technique for obtaining germ-free chickens was investigated. Various disinfection tests of the material and the eggs have been performed with chemical agents. The weak frequency of internal contamination of the eggs (0.4 p. 100), if collected in good hygienic conditions and dipped the same day in a I per 100 solution of mercuric chloride, allows sterile hatchings in 100 fertilized eggs batches to be obtained. The sterilization of the isolator-hatching box was performed by pulverization of a I per 100 solution of quaternary ammonium, followed by a formaldehyde fumigation. The material passed through an antiseptic bath (liquid-lock) of I per 100 quaternary ammonium in water. This technique yielded 250 chickens, in 12 successive lots, that were bred until 15 days to 6 weeks, without bacteriological contamination. PMID:1028382

  7. Emerging Therapeutic Targets for Male Germ Cell Tumors.

    PubMed

    Fankhauser, Christian Daniel; Honecker, Friedemann; Beyer, Jörg; Bode, Peter Karl

    2015-12-01

    Male germ cell tumors (GCTs) are curable cancers, yet 10-15 % of patients with metastatic disease fail cisplatin-based first-line treatments. While therapeutic options have increased for various other cancers, little progress has been made in the management of GCT in the last decades. A better understanding of the molecular alterations underlying the disease and identification of new therapeutic targets are needed. Several phase I/II studies with promising new agents are ongoing or have been completed, but most of those trials have been small and have not included translational research. Therefore, molecular profiles predictive for response or new agents have not been identified in male GCT so far. The purpose of this review is to highlight emerging targets and therapies with the potential to improve systemic treatment of metastatic male GCT and to develop strategies for future clinical trials. PMID:26449842

  8. Germ Cell Sex Determination: A Collaboration between Soma and Germline

    PubMed Central

    Murray, Sheryl M.; Yang, Shu Yuan; Van Doren, Mark

    2010-01-01

    Sex determination is regulated very differently in the soma vs. the germline, yet both processes are critical for the creation of the male and female gametes. In general, the soma plays an essential role in regulating sexual identity of the germline. However, in some species, such as Drosophila and mouse, the sex chromosome constitution of the germ cells makes an autonomous contribution to germline sexual development. Here we review how the soma and germline cooperate to determine germline sexual identity for some important model systems, the fly, the worm and the mouse, and discuss some of the implications of “dual control” (soma plus germline) as compared to species where germline sex is dictated only by the surrounding soma. PMID:21030233

  9. Possibilities in Germ Cell Research: An Engineering Insight.

    PubMed

    Esfandiari, Fereshteh; Mashinchian, Omid; Ashtiani, Mohammad Kazemi; Ghanian, Mohammad Hossein; Hayashi, Katsuhiko; Saei, Amir Ata; Mahmoudi, Morteza; Baharvand, Hossein

    2015-12-01

    Germ cells (GCs) are responsible for fertility and disruptions in their development or function cause infertility. However, current knowledge about the diverse mechanisms involved in GC development and function is still in its infancy. This is mainly because there are low numbers of GCs, especially during embryonic development. A deeper understanding of GCs would enhance our ability to produce them from stem cells. In addition, such information would enable the production of healthy gametes for infertile couples. In this regard, pluripotent stem cells (PSCs) demonstrated a promising ability to produce GCs in vitro. In this review, we highlight recent advances in the field of tissue engineering that suggest novel strategies to enhance GC research. PMID:26497427

  10. Defining the optimal treatment for clinical stage I nonseminomatous germ cell testicular cancer using decision analysis.

    PubMed

    Nguyen, Carvell T; Fu, Alex Z; Gilligan, Timothy D; Wells, Brian J; Klein, Eric A; Kattan, Michael W; Stephenson, Andrew J

    2010-01-01

    PURPOSE There is equipoise regarding the optimal treatment of clinical stage (CS) I nonseminomatous germ cell testicular cancer (NSGCT). Formal mechanisms that enable patients to consider cancer outcomes, treatment-related morbidity, and personal preferences are needed to facilitate decision making between retroperitoneal lymph node dissection (RPLND), primary chemotherapy, and surveillance. METHODS Decision analysis was performed using a Markov model that incorporated likelihoods of survival, treatment-related morbidity, and utilities for seven undesired post-treatment health states to estimate the quality-adjusted survival (QAS) for each treatment option. Utilities were obtained from 24 hypothetical NSGCT patients using a visual analog (rating) scale and standard gamble. Results Overall, QAS associated with each treatment was high and differences in QAS were small. Surveillance was the preferred intervention for patients with a risk of relapse less than 33% and 37% using the rating scale and standard-gamble method of utility assessment, respectively. Active treatment was favored over surveillance for patients with relapse risk on surveillance greater than 33% and 37% by the rating scale (RPLND preferred) and standard-gamble methods (primary chemotherapy preferred), respectively. Substantial differences in average utilities were seen depending on the method used. By the rating scale, patients substantially devalued life in six of seven undesired health states but they were surprisingly tolerant of treatment-related morbidity using standard gamble. CONCLUSION A decision model has been developed for CS I NSGCT that estimates QAS for RPLND, primary chemotherapy, and surveillance by considering cancer outcomes, morbidity, and patient preferences. Surveillance was the preferred intervention for all except those patients at high risk for relapse. PMID:19917846

  11. 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, β1- and α6-integrins (ITΒ1, 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, α6 integrin; 1.26±0.53, β1 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

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

    PubMed

    Pacchiarini, Tiziana; Sarasquete, Carmen; Cabrita, Elsa

    2014-06-01

    Interspecific testicular germ cell (TGC) transplantation was investigated in two commercial flatfish species. Testes from donor species (Senegalese sole) were evaluated using classical histological techniques (haematoxylin-eosin staining and haematoxylin-light green-orange G-acid fuchsine staining), in situ hybridisation and immunohistochemical analysis. Both Ssvasa1-2 mRNAs and SsVasa protein allowed the characterisation of TGCs, confirming the usefulness of the vasa gene in the detection of Senegalese sole TGCs. Xenogenic transplants were carried out using TGCs from one-year-old Senegalese sole into turbot larvae. Propidium iodide-SYBR-14 and 4',6'-diamidino-2-phenylindole (DAPI) staining showed that 87.98% of the extracted testicular cells were viable for microinjection and that 15.63% of the total recovered cells were spermatogonia. The vasa gene was characterised in turbot recipients using cDNA cloning. Smvasa mRNA was confirmed as a germ cell-specific molecular marker in this species. Smvasa expression analysis during turbot ontogeny was carried out before Senegalese sole TGC transplants into turbot larvae. Turbot larvae at 18 days after hatching (DAH) proved to be susceptible to manipulation procedures. High survival rates (83.75±15.90-100%) were obtained for turbot larvae at 27, 34 and 42 DAH. These data highlight the huge potential of this species for transplantation studies. Quantitative PCR was employed to detect Senegalese sole vasa mRNAs (Ssvasa1-2) in the recipient turbot larvae. The Ssvasa mRNAs showed a significant increase in relative expression in 42-DAH microinjected larvae three weeks after treatment, showing the proliferation of Senegalese sole spermatogonia in transplanted turbot larvae. PMID:23735683

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

    PubMed

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

    2011-08-01

    A novel and scalable method has been developed to enable control of the ice nucleation step for the freezing process during lyophilization. This method manipulates the chamber pressure of the freeze dryer to simultaneously induce nucleation in all product vials at a desired temperature. The effects of controlled nucleation on the drying rate of various formulations including 5% (w/w) mannitol, 5% (w/w) sucrose, and a mixture of 3% (w/w) mannitol and 2% (w/w) sucrose were studied. For a 5% (w/w) mannitol, uncontrolled ice nucleation occurred randomly at product temperatures between -8.0°C and -15.9°C as the vials were cooled to -40°C. Controlled ice nucleation was achieved at product temperatures between -2.3°C and -3.7°C. The effect of nucleation control on the effective pore radius (r(e) ) of the cake was determined from the product temperature profiles using a pore diffusion model in combination with a nonlinear parameter estimation approach reported earlier. Results show that the value of r(e) for 5% (w/w) mannitol was enlarged from 13 to 27 μm by uniformly inducing nucleation at higher temperatures. Applying the resistance parameters obtained from the pore diffusion model for 5% (w/w) mannitol, optimized cycles were theoretically generated and experimentally tested, resulting in a 41% reduction in primary drying time. PMID:21465488

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

    PubMed

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

    2015-12-15

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

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

    PubMed

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

    2015-01-01

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

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

    SciTech Connect

    Ellis, R.; Kimble, J.

    1995-02-01

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

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

    PubMed Central

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

    2008-01-01

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

  18. Gene expression in the axolotl germ line: Axdazl, Axvh, Axoct-4, and Axkit.

    PubMed

    Bachvarova, Rosemary F; Masi, Thomas; Drum, Matthew; Parker, Nathan; Mason, Ken; Patient, Roger; Johnson, Andrew D

    2004-12-01

    Primordial germ cells (PGCs) in embryos of mammals and urodele amphibians are formed by induction in the absence of germ plasm. We describe expression of four germ cell-related genes through the germ cell cycle of the axolotl. The orthologs of vasa and daz-like are up-regulated in PGCs of tail bud embryos before the gonad forms and are expressed throughout the female germ cell cycle. Mammalian Oct-4 is a marker of pluripotency in embryonic cells. Axolotl Oct-4 has higher homology to Oct-4 than that found in other vertebrates. It is expressed in the equivalent of the mouse epiblast, in the posterior mesoderm of late gastrulae that gives rise to PGCs, and in diplotene growing oocytes, but not in presumptive PGCs after gastrulation. Finally, a c-kit homolog is expressed in gonadal oogonia and growing oocytes as in mice but is also not found in PGCs. The expression pattern in urodele gonadal germ cells is similar to that of other vertebrates, although the pattern in pregonadal PGCs is distinctly different from that of mice. We conclude that PGCs are restricted to the germ line later in urodeles than in mice or lack migration and proliferation programs. PMID:15517581

  19. Generation of male differentiated germ cells from various types of stem cells.

    PubMed

    Hou, Jingmei; Yang, Shi; Yang, Hao; Liu, Yang; Liu, Yun; Hai, Yanan; Chen, Zheng; Guo, Ying; Gong, Yuehua; Gao, Wei-Qiang; Li, Zheng; He, Zuping

    2014-06-01

    Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10-15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells 'especially functional spermatids' is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients. PMID:24534952

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-01

    We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. PMID:25794557

  3. 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

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

    PubMed

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

    2015-11-15

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

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

    SciTech Connect

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

    1989-09-01

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

  6. [A multi-disciplinary approach to the treatment of germ cell tumors].

    PubMed

    Honecker, F; Souchon, R; Krege, S; Bokemeyer, C

    2010-11-01

    The management of patients with germ cell tumors must be based upon complete staging and should be risk-adapted. Seminoma stage I can be managed by either active surveillance, adjuvant carboplatin therapy, or radiotherapy. Seminoma stage IIA should receive radiotherapy, stage IIB can be managed with either radiotherapy or chemotherapy. Seminoma stage IIC and III are treated with three (to four) cycles of PEB (cisplatin, etoposide, bleomycin). Nonseminoma stage I should be managed by either active surveillance or adjuvant chemotherapy with one (to two) cycles of PEB, based upon the risk factor vascular invasion. Treatment of advanced nonseminoma consists of either 3 or 4 cycles of PEB and must be guided by the IGCCCG prognostic subgroup. Prognosis is particularly poor in patients with either primary mediastinal nonseminoma, and/or metastases to liver, brain or bone, or inadequate tumor marker decline. In these cases, intensification of therapy with high dose chemotherapy can be justified. Complex cases with poor prognosis and all patients with relapsed disease should exclusively be treated by experts in a tertiary care setting to achieve highest possible cure rates in these young patients. PMID:20938625

  7. Mediastinal Germ Cell Tumor Exhibiting a Discrepancy between Tumor Markers and Imaging: A Case Study

    PubMed Central

    Takenaka, Kei; Mukohara, Toru; Hirai, Chihoko; Funakoshi, Yohei; Nakamura, Yukiko; Chayahara, Naoko; Toyoda, Masanori; Kiyota, Naomi; Itoh, Tomoo; Yokozaki, Hiroshi; Minami, Hironobu

    2015-01-01

    We report a mediastinal germ cell tumor (GCT) that exhibited a discrepancy between the time course of serum human chorionic gonadotropin (hCG) levels and clinical consequences. An otherwise healthy man, aged 34 years, was diagnosed with a nonseminomatous GCT, most likely embryonal carcinoma (EC), based on a mediastinal tumor biopsy. Standard chemotherapy resulted in an optimal decrease in serum hCG levels. However, multiple lesions in the liver continued to enlarge, which led to his death. Autopsy revealed few viable tumor cells in the liver, with the great majority of the tumor cells appearing to have undergone necrosis, suggesting that they responded to the chemotherapy. The residual tumor cells in the mediastinum and the liver were similar to syncytiotrophoblast cells, suggesting a cho-riocarcinoma (CC). On immunohistochemical analysis, the mediastinal tumor cells in the diagnostic biopsy specimen expressed both CD30 and hCG, whereas residual mediastinal and hepatic tumor cells in the autopsy specimen after chemotherapy also expressed hCG, but not CD30. These findings suggested that the patient suffered from a primary mixed GCT consisting of an EC and a CC. Both pre- and postchemotherapy tumors strongly expressed matrix metalloproteinase-2, supporting the aggressive and invasive features of the tumor phenotype. We speculate that the extremely invasive tumor destroyed normal liver structure, whereas chemotherapy and central necrosis reduced the number of viable cells themselves, causing a discordant decrease in serum hCG levels. PMID:26351441

  8. DDX3X, the X homologue of AZFa gene DDX3Y, expresses a complex pattern of transcript variants only in the male germ line.

    PubMed

    Rauschendorf, Marc-Alexander; Zimmer, Jutta; Ohnmacht, Caroline; Vogt, Peter H

    2014-12-01

    DDX3X, the functional X homologue of the major AZFa gene, DDX3Y, belongs to the highly conserved PL10-subfamily of DEAD-box RNA helicase genes which are functionally conserved from yeast to man. They are mainly involved in cell cycle control and translation initiation control of gene transcripts with long 5'UTR extensions containing complex secondary structures. Interestingly, in humans both gene copies were found to be expressed at different phases of human spermatogenesis. Whereas DDX3Y transcripts are translated only in premeiotic male germ cells, the DDX3X protein is expressed only in postmeiotic spermatids. In this study, we found that the major class of DDX3X transcripts in human testis become activated first after meiosis and at a specific core promoter not active in somatic tissues and not present upstream of the DDX3Y homologue. Two alternative 5'UTR transcript lengths are subsequently produced by an additional testis-specific 5'UTR splicing event. Both transcripts are mainly processed for polyadenylation in their proximal 3'UTR. A minor transcript class starting at the same male germ line-specific core promoter produces primary transcripts with an extremely long 3'UTR (? 17 kb), which is subsequently spliced at distinct sites resulting in six short 3'UTR splice variants (I-VI). Comparative analyses of the DDX3X transcripts in mouse and primates revealed that this complex pattern of male germ line-specific transcript variants first evolved in primates. Our data thus suggest complex translational control mechanism(s) for the human DDX3X gene locus functioning only in the male germ line and resulting in expression of its protein only in the postmeiotic spermatids. PMID:25208899

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

    PubMed

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

    2012-01-01

    Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines.We focussed on the early stages of infection by Bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. Skin explants of Alytes muletensis, Litoria caerulea and Xenopus leavis were exposed to Bd in an Ussing chamber for 3 to 5 days. Early interactions of Bd with amphibian skin were observed using light microscopy and transmission electron microscopy. To validate the observations in vitro, comparison was made with skin from experimentally infected frogs. Additional in vitro experiments were performed to elucidate the process of intracellular colonization in L. caerulea. Early interactions of Bd with amphibian skin are: attachment of zoospores to host skin, zoospore germination, germ tube development, penetration into skin cells, invasive growth in the host skin, resulting in the loss of host cell cytoplasm. Inoculation of A. muletensis and L. caerulea skin was followed within 24 h by endobiotic development, with sporangia located intracellularly in the skin. Evidence is provided of how intracellular colonization is established and how colonization by Bd proceeds to deeper skin layers. Older thalli develop rhizoid-like structures that spread to deeper skin layers, form a swelling inside the host cell to finally give rise to a new thallus. In X. laevis, interaction of Bd with skin was limited to an epibiotic state, with sporangia developing upon the skin. Only the superficial epidermis was affected. Epidermal cells seemed to be used as a nutrient source without development of intracellular thalli. The in vitro data agreed with the results obtained after experimental infection of the studied frog species. These data suggest that the colonization strategy of B. dendrobatidis is host dependent, with the extent of colonization most likely determined by inherent characteristics of the host epidermis. PMID:22911798

  10. 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

  11. Sequence-dependent but not sequence-specific piRNA adhesion traps mRNAs to the germ plasm.

    PubMed

    Vourekas, Anastassios; Alexiou, Panagiotis; Vrettos, Nicholas; Maragkakis, Manolis; Mourelatos, Zissimos

    2016-03-17

    The conserved Piwi family of proteins and piwi-interacting RNAs (piRNAs) have a central role in genomic stability, which is inextricably linked to germ-cell formation, by forming Piwi ribonucleoproteins (piRNPs) that silence transposable elements. In Drosophila melanogaster and other animals, primordial germ-cell specification in the developing embryo is driven by maternal messenger RNAs and proteins that assemble into specialized messenger ribonucleoproteins (mRNPs) localized in the germ (pole) plasm at the posterior of the oocyte. Maternal piRNPs, especially those loaded on the Piwi protein Aubergine (Aub), are transmitted to the germ plasm to initiate transposon silencing in the offspring germ line. The transport of mRNAs to the oocyte by midoogenesis is an active, microtubule-dependent process; mRNAs necessary for primordial germ-cell formation are enriched in the germ plasm at late oogenesis via a diffusion and entrapment mechanism, the molecular identity of which remains unknown. Aub is a central component of germ granule RNPs, which house mRNAs in the germ plasm, and interactions between Aub and Tudor are essential for the formation of germ granules. Here we show that Aub-loaded piRNAs use partial base-pairing characteristics of Argonaute RNPs to bind mRNAs randomly in Drosophila, acting as an adhesive trap that captures mRNAs in the germ plasm, in a Tudor-dependent manner. Notably, germ plasm mRNAs in drosophilids are generally longer and more abundant than other mRNAs, suggesting that they provide more target sites for piRNAs to promote their preferential tethering in germ granules. Thus, complexes containing Tudor, Aub piRNPs and mRNAs couple piRNA inheritance with germline specification. Our findings reveal an unexpected function for piRNP complexes in mRNA trapping that may be generally relevant to the function of animal germ granules. PMID:26950602

  12. Metastatic Treated Malignant Germ Cell Tumors: Is SALL4 a Better Marker Than Placental Alkaline Phosphatase?

    PubMed

    Andeen, Nicole K; Tretiakova, Maria S

    2016-03-01

    Studies have shown that in the metastatic setting and after treatment, expression of immunohistochemical markers may be diminished or lost. Transcription factor SALL4 (sal-like protein 4) has been recognized as a sensitive marker for both primary and metastatic malignant germ cell tumors (MGCTs), but has not been tested in the posttreatment setting. We sought to determine the level of SALL4 expression in treatment-resistant metastatic MGCT in comparison with pan-GCT marker placental alkaline phosphatase (PLAP). Thirty-six previously treated MGCTs, 16 untreated primary testicular MGCTs, and 4 cytology specimens were immunostained for SALL4 and PLAP, and staining characteristics were evaluated. In the treated MGCT group, there was diffuse SALL4 nuclear immunoreactivity in the majority of cases (27/36, 75%), labeling seminoma, yolk-sac tumor, embryonal carcinoma, and primitive neuroectodermal components. No treated metastatic MGCT lacked SALL4 immunoreactivity. In contrast, PLAP was diffusely expressed in only 14/36 (39%) cases of treated MGCTs, showed scattered focal weak to moderate positivity in 13/36 (36%), and was virtually absent in 9/36 (25%) cases. Both markers had scattered expression limited to the epithelial components of teratomatous regions. SALL4 also outperformed PLAP on a small sample of cytology blocks. Although SALL4 is not entirely specific, it is a highly sensitive marker with strong diffuse nuclear reactivity in the majority of MGCTs in the posttreatment setting, at significantly higher levels than PLAP (P<0.001). Persistent expression of SALL4 in metastatic MGCTs resistant to chemoradiation also raises the possibility for targeted systemic therapy as the anti-SALL4 peptide continues to be developed. PMID:25906119

  13. Avoiding bad genes: oxidatively damaged DNA in germ line and mate choice.

    PubMed

    Velando, Alberto; Torres, Roxana; Alonso-Alvarez, Carlos

    2008-11-01

    August Weismann proposed that genetic changes in somatic cells cannot pass to germ cells and hence to next generations. Nevertheless, evidence is accumulating that some environmental effects can promote heritable changes in the DNA of germ cells, which implies that some somatic influence on germ line is possible. This influence is mostly detrimental and related to the presence of oxidative stress, which induces mutations and epigenetic changes. This effect should be stronger in males due to the particular characteristics of sperm. Here, we propose the hypothesis that females are able to avoid males with oxidatively damaged DNA in the germ line by using oxidative-dependent (pre- and post-mating) signals. This new hypothesis may shed light on unsolved questions in evolutionary biology, such as the benefits of polyandry, the lek paradox, or the role of sexual selection on the evolution of aging. PMID:18937375

  14. Identification of Novel Long Noncoding RNA Transcripts in Male Germ Cells

    PubMed Central

    Lee, Tin-Lap; Xiao, Amy; Rennert, Owen M.

    2013-01-01

    Emerging evidence from these studies suggested that the male germ cell transcriptome is more complex than previously envisioned. In addition to protein-coding genes, the transcriptome also encodes a significant number of nonprotein-coding transcripts. These noncoding (nc) RNAs appear to be involved in a variety of cellular activities, ranging from simple housekeeping to complex regulatory functions. A class of ncR-NAs known as long ncRNAs (lncRNAs) were recently shown to be expressed in a developmentally regulated manner during brain and embryonic stem cell development. This protocol aims to predict and identify potential lncRNA candidates using Serial Analysis of Gene Expression (SAGE) data. We also illustrate how to validate the potential lncRNAs by expression analyses using real-time PCR and Northern Blot. Potential lncRNA candidates in male germ cells are identified using our previously established male germ cell SAGE database (GermSAGE). PMID:22144240

  15. Involvement of epigenetic modifiers in the pathogenesis of testicular dysgenesis and germ cell cancer.

    PubMed

    Lawaetz, Andreas C; Almstrup, Kristian

    2015-06-01

    Testicular germ cell cancer manifests mainly in young adults as a seminoma or non-seminoma. The solid tumors are preceded by the presence of a non-invasive precursor cell, the carcinoma in situ cell (CIS), which shows great similarity to fetal germ cells. It is therefore hypothesized that the CIS cell is a fetal germ cell that has been arrested during development due to testicular dysgenesis. CIS cells retain a fetal and open chromatin structure, and recently several epigenetic modifiers have been suggested to be involved in testicular dysgenesis in mice. We here review the possible involvement of epigenetic modifiers with a focus on jumonji C enzymes in the development of testicular dysgenesis and germ cell cancer in men. PMID:26103631

  16. Offspring from oocytes derived from in vitro primordial germ cell-like cells in mice.

    PubMed

    Hayashi, Katsuhiko; Ogushi, Sugako; Kurimoto, Kazuki; Shimamoto, So; Ohta, Hiroshi; Saitou, Mitinori

    2012-11-16

    Reconstitution of female germ cell development in vitro is a key challenge in reproductive biology and medicine. We show here that female (XX) embryonic stem cells and induced pluripotent stem cells in mice are induced into primordial germ cell-like cells (PGCLCs), which, when aggregated with female gonadal somatic cells as reconstituted ovaries, undergo X-reactivation, imprint erasure, and cyst formation, and exhibit meiotic potential. Upon transplantation under mouse ovarian bursa, PGCLCs in the reconstituted ovaries mature into germinal vesicle-stage oocytes, which then contribute to fertile offspring after in vitro maturation and fertilization. Our culture system serves as a robust foundation for the investigation of key properties of female germ cells, including the acquisition of totipotency, and for the reconstitution of whole female germ cell development in vitro. PMID:23042295

  17. 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.

  18. CDC Vital Signs: Making Health Care Safer -- Stop Infections from Lethal CRE Germs Now

    MedlinePLUS

    ... 62 MB] Read the MMWR Science Clips Making Health Care Safer Stop Infections from Lethal CRE Germs Now ... to otherwise healthy people outside of medical facilities. Health Care Providers can Know if patients in your facility ...

  19. 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.

  20. Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field.

    PubMed

    Yamamoto, Naomi; Oshima, Masamitsu; Tanaka, Chie; Ogawa, Miho; Nakajima, Kei; Ishida, Kentaro; Moriyama, Keiji; Tsuji, Takashi

    2015-01-01

    The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force. PMID:26673152

  1. Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field

    PubMed Central

    Yamamoto, Naomi; Oshima, Masamitsu; Tanaka, Chie; Ogawa, Miho; Nakajima, Kei; Ishida, Kentaro; Moriyama, Keiji; Tsuji, Takashi

    2015-01-01

    The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force. PMID:26673152

  2. Conservation of migration and differentiation circuits in primordial germ cells between avian species.

    PubMed

    Park, Tae Sub; Han, Jae Yong

    2013-01-01

    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

  3. 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

  4. 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

  5. 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.

  6. Multidimensional representations: The knowledge domain of germs held by students, teachers and medical professionals

    NASA Astrophysics Data System (ADS)

    Rua, Melissa Jo

    The present study examined the understandings held by 5th, 8th, and 11th-grade students, their teachers and medical professionals about germs. Specifically, this study describes the content and structure of students' and adults' conceptions in the areas of germ contraction, transmission, and treatment of infectious and non-infectious diseases caused by microorganisms. Naturalistic and empirical research methods were used to investigate participants' conceptions. Between and within group similarities were found using data from concept maps on the topic "flu," drawings of germs, a 20 word card sort related to germs and illness, and a semi-structured interview. Concept maps were coded according to techniques by Novak and Gowan (1984). Drawings of germs were coded into four main categories (bacteria, viruses, animal cell, other) and five subcategories (disease, caricature, insect, protozoa, unclassified). Cluster patterns for the card sorts of each group were found using multidimensional scaling techniques. Six coding categories emerged from the interview transcripts: (a) transmission, (b) treatment, (c) effect of weather on illness, (d) immune response, (e) location of germs, and (f) similarities and differences between bacteria and viruses. The findings showed students, teachers and medical professionals have different understandings about bacteria and viruses and the structures of those understandings vary. Gaps or holes in the participants knowledge were found in areas such as: (a) how germs are transmitted, (b) where germs are found, (c) how the body transports and uses medicine, (d) how the immune system functions, (e) the difference between vaccines and non-prescription medicines, (f) differences that exist between bacteria and viruses, and (g) bacterial resistance to medication. The youngest students relied heavily upon personal experiences with germs rather than formal instruction when explaining their conceptions. As a result, the influence of media was evident in the students' understandings and images of microbes. Students also viewed germs as a human problem rather than seeing microorganisms as an independent member of the ecosystem. Teachers' explanations about germs varied in explicitness based on the grade level they taught while medical professionals based their understandings on formal knowledge and tended to use explicit technical language in their explanations of the phenomena.

  7. Localisation of RNAs into the Germ Plasm of Vitellogenic Xenopus Oocytes

    PubMed Central

    Nijjar, Sarbjit; Woodland, Hugh R.

    2013-01-01

    We have studied the localisation of mRNAs in full-grown Xenopus laevis oocytes by injecting fluorescent RNAs, followed by confocal microscopy of the oocyte cortex. Concentrating on RNA encoding the Xenopus Nanos homologue, nanos1 (formerly Xcat2), we find that it consistently localised into aggregated germ plasm ribonucleoprotein (RNP) particles, independently of cytoskeletal integrity. This implies that a diffusion/entrapment-mediated mechanism is active, as previously reported for previtellogenic oocytes. Sometimes this was accompanied by localisation into scattered particles of the “late”, Vg1/VegT pathway; occasionally only late pathway localisation was seen. The Xpat RNA behaved in an identical fashion and for neither RNA was the localisation changed by any culture conditions tested. The identity of the labelled RNP aggregates as definitive germ plasm was confirmed by their inclusion of abundant mitochondria and co-localisation with the germ plasm protein Hermes. Further, the nanos1/Hermes RNP particles are interspersed with those containing the germ plasm protein Xpat. These aggregates may be followed into the germ plasm of unfertilized eggs, but with a notable reduction in its quantity, both in terms of injected molecules and endogenous structures. Our results conflict with previous reports that there is no RNA localisation in large oocytes, and that during mid-oogenesis even germ plasm RNAs localise exclusively by the late pathway. We find that in mid oogenesis nanos1 RNA also localises to germ plasm but also by the late pathway. Late pathway RNAs, Vg1 and VegT, also may localise into germ plasm. Our results support the view that mechanistically the two modes of localisation are extremely similar, and that in an injection experiment RNAs might utilise either pathway, the distinction in fates being very subtle and subject to variation. We discuss these results in relation to their biological significance and the results of others. PMID:23626739

  8. Germ Line Versus Soma in the Transition from Egg to Embryo.

    PubMed

    Swartz, S Zachary; Wessel, Gary M

    2015-01-01

    With few exceptions, all animals acquire the ability to produce eggs or sperm at some point in their life cycle. Despite this near-universal requirement for sexual reproduction, there exists an incredible diversity in germ line development. For example, animals exhibit a vast range of differences in the timing at which the germ line, which retains reproductive potential, separates from the soma, or terminally differentiated, nonreproductive cells. This separation may occur during embryonic development, after gastrulation, or even in adults, depending on the organism. The molecular mechanisms of germ line segregation are also highly diverse, and intimately intertwined with the overall transition from a fertilized egg to an embryo. The earliest embryonic stages of many species are largely controlled by maternally supplied factors. Later in development, patterning control shifts to the embryonic genome and, concomitantly with this transition, the maternally supplied factors are broadly degraded. This chapter attempts to integrate these processes--germ line segregation, and how the divergence of germ line and soma may utilize the egg to embryo transitions differently. In some embryos, this difference is subtle or maybe lacking altogether, whereas in other embryos, this difference in utilization may be a key step in the divergence of the two lineages. Here, we will focus our discussion on the echinoderms, and in particular the sea urchins, in which recent studies have provided mechanistic understanding in germ line determination. We propose that the germ line in sea urchins requires an acquisition of maternal factors from the egg and, when compared to other members of the taxon, this appears to be a derived mechanism. The acquisition is early--at the 32-cell stage--and involves active protection of maternal mRNAs, which are instead degraded in somatic cells with the maternal-to-embryonic transition. We collectively refer to this model as the Time Capsule method for germ line determination. PMID:26358873

  9. PHYSICAL ACTIVITY IN ADOLESCENCE AND TESTICULAR GERM CELL CANCER RISK

    PubMed Central

    Littman, Alyson J; Doody, David R; Biggs, Mary L; Weiss, Noel S; Starr, Jacqueline R; Schwartz, Stephen M

    2010-01-01

    Objective Several, but not all, studies have observed increased risks of testicular germ cell cancer (TGCC) associated with bicycling and other recreational activities. To further examine whether physical activity (PA) in adolescence is associated with TGCC risk, the authors conducted a case-control study in western Washington State. Methods Cases (n=391) were men diagnosed with TGCC who were identified through a population-based cancer registry. Controls (n=1023) were men identified from the general population in western Washington State by using random digit telephone dialing. Participants were queried about various specific PA in grades 7–12 including bicycling, horseback riding, competitive sports, physical education class, as well as moderate, vigorous, and sedentary activities in general. Results In multivariate analyses, bicycling, vigorous-intensity activities, and sedentary activities were not associated with TGCC risk, while horseback riding and wrestling were associated with decreased risks, and moderate-intensity activities, soccer, basketball and intermediate duration of competitive activities were associated with increased risks. Conclusions The lack of internal consistency of the findings within the current study and of findings among prior studies, suggests that PA contributes little, if any, to the risk of TGCC. PMID:19399630

  10. Morphometric Approach to Pulp Fibroblast Development in Tooth Germ

    PubMed Central

    Căruntu, Irina-Draga; Săvinescu, Sergiu Daniel; Amălinei, Cornelia

    2014-01-01

    This paper builds a morphometric framework for the analysis of dental pulp fibroblast evolution during tooth development. We investigated 15 tooth germs (cases) organized, by histological criteria, in three groups corresponding to cap, early bell, and late bell stages, respectively. Each group comprised five cases. The morphometric description used the following parameters: area (A), perimeter (P)—automatically extracted by a color segmentation technique, and form factor (FF)—calculated as 4πA/P2. The designed framework operated at inter- and intragroup levels. The intergroup analysis quantified the differences between groups, in the sense of a relative distance (RD) adequately defined by mean-value scaling. We showed that the stage of early bell is approximately 5 times closer to late bell than to cap. The quantification procedure required concomitant information about A, P parameters (as P versus A dependences, or FF values), whereas the procedure failed for A or P separately used. The intragroup analysis quantified the similarity of the cases belonging to the same stage. We proved that, unlike the intergroup tests, the individual exploitation of all three descriptors A, P, and FF is effective, yielding highly compatible results. Within any group, most cases presented RDs less than 10% from the group mean value, regardless of the descriptor type. PMID:25057501

  11. NANOG priming before full reprogramming may generate germ cell tumours.

    PubMed

    Grad, I; Hibaoui, Y; Jaconi, M; Chicha, L; Bergström-Tengzelius, R; Sailani, M R; Pelte, M F; Dahoun, S; Mitsiadis, T A; Töhönen, V; Bouillaguet, S; Antonarakis, S E; Kere, J; Zucchelli, M; Hovatta, O; Feki, A

    2011-01-01

    Reprogramming somatic cells into a pluripotent state brings patient-tailored, ethical controversy-free cellular therapy closer to reality. However, stem cells and cancer cells share many common characteristics; therefore, it is crucial to be able to discriminate between them. We generated two induced pluripotent stem cell (iPSC) lines, with NANOG pre-transduction followed by OCT3/4, SOX2, and LIN28 overexpression. One of the cell lines, CHiPS W, showed normal pluripotent stem cell characteristics, while the other, CHiPS A, though expressing pluripotency markers, failed to differentiate and gave rise to germ cell-like tumours in vivo. Comparative genomic hybridisation analysis of the generated iPS lines revealed that they were genetically more stable than human embryonic stem cell counterparts. This analysis proved to be predictive for the differentiation potential of analysed cells. Moreover, the CHiPS A line expressed a lower ratio of p53/p21 when compared to CHiPS W. NANOG pre-induction followed by OCT3/4, SOX2, MYC, and KLF4 induction resulted in the same tumour-inducing phenotype. These results underline the importance of a re-examination of the role of NANOG during reprogramming. Moreover, this reprogramming method may provide insights into primordial cell tumour formation and cancer stem cell transformation. PMID:22071697

  12. Polychlorinated biphenyls and risk of testicular germ cell tumors

    PubMed Central

    McGlynn, Katherine A.; Quraishi, Sabah M.; Graubard, Barry I.; Weber, Jean-Philippe; Rubertone, Mark V.; Erickson, Ralph L.

    2009-01-01

    Exposure to endocrine disrupting chemicals, such as polychlorinated biphenyls (PCBs), may alter hormonal balance and thereby, increase risk of testicular germ cell tumors (TGCT). To study the relationship of PCBs to TGCT, pre-diagnostic serum samples from 736 cases and 913 controls in the Servicemen’s Testicular Tumor Environmental and Endocrine Determinants study were analyzed. Adjusted odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. PCB levels were examined in association with all TGCT and, separately, with each histologic type (seminoma, nonseminoma). Risks associated with seven functional groupings of PCBs, as well as sum of PCBs, were also examined. There were significantly decreased risks of TGCT in association with eight PCBs (PCB-118, PCB-138, PCB-153, PCB-156, PCB-163, PCB-170, PCB-180, PCB-187) and no association with the remaining three (PCB-99, PCB-101, PCB-183). The same eight congeners were significantly associated with decreased risk of nonseminoma, while five (PCB-138, PCB-153, PCB-156, PCB-163, PCB-170) were associated with decreased risk of seminoma. All functional groupings of PCBs were also associated with decreased risk of TGCT and of nonseminoma, while 3 of the 7 functional groups were associated with decreased risk of seminoma. Sum of PCBs was significantly associated with decreased risk of TGCT (ptrend=0.0008), nonseminoma (ptrend=0.001) and seminoma (ptrend=0.03). Overall, these data do not support the hypothesis that PCB exposure increases the risk of TGCT. PMID:19223531

  13. The Origin And Migration Of Primordial Germ Cells In Sturgeons

    PubMed Central

    Saito, Taiju; Pšeni?ka, Martin; Goto, Rie; Adachi, Shinji; Inoue, Kunio; Arai, Katsutoshi; Yamaha, Etsuro

    2014-01-01

    Primordial germ cells (PGCs) arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser) have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT) assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts. PMID:24505272

  14. 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

  15. [A mixed germ cell tumor that underwent dramatic size changes].

    PubMed

    Kuwayama, Kazuyuki; Takai, Hiroki; Nishiyama, Akira; Hirai, Satoshi; Yokosuka, Kimihiko; Toi, Hiroyuki; Hirano, Kazuhiro; Matsubara, Shunji; Uno, Masaaki; Nishimura, Hirotake

    2014-09-01

    This report describes a mixed germ cell tumor that underwent dramatic size changes. A 12-year-old boy presented to our hospital with a headache that had persisted for two months. Initial magnetic resonance imaging (MRI) revealed a pineal tumor and hydrocephalus. The patient required external ventricular drainage and underwent two endoscopic biopsies. His evaluation involved a total of nine computed tomography (CT) scans prior to the second biopsy;the tumor size had decreased before the second endoscopic biopsy. The tumor consisted of both a germinoma and a teratoma component. The patient was treated with three courses of carboplatin-etoposide (CBDCA-VP) chemotherapy and whole-ventricle radiotherapy (32.1 Gy). However, during the adjuvant therapy, the tumor size increased, necessitating total tumor resection. We speculate that the tumor's initial size reduction was caused by leakage of the cyst component and exposure to the brain CT irradiation. The tumor's subsequent increase in size was due to the recollection of the cystic components and intracranial growing teratoma syndrome (iGTS). Therefore, frequent brain CTs and angiography should be avoided before definitive pathological diagnosis is achieved. Further, the tumor size should be considered, with surgical resection being performed at the optimal time. PMID:25179200

  16. 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.

  17. Tooth germ invagination from cell-cell interaction: Working hypothesis on mechanical instability.

    PubMed

    Takigawa-Imamura, Hisako; Morita, Ritsuko; Iwaki, Takafumi; Tsuji, Takashi; Yoshikawa, Kenichi

    2015-10-01

    In the early stage of tooth germ development, the bud of the dental epithelium is invaginated by the underlying mesenchyme, resulting in the formation of a cap-like folded shape. This bud-to-cap transition plays a critical role in determining the steric design of the tooth. The epithelial-mesenchymal interaction within a tooth germ is essential for mediating the bud-to-cap transition. Here, we present a theoretical model to describe the autonomous process of the morphological transition, in which we introduce mechanical interactions among cells. Based on our observations, we assumed that peripheral cells of the dental epithelium bound tightly to each other to form an elastic sheet, and mesenchymal cells that covered the tooth germ would restrict its growth. By considering the time-dependent growth of cells, we were able to numerically show that the epithelium within the tooth germ buckled spontaneously, which is reminiscent of the cap-stage form. The difference in growth rates between the peripheral and interior parts of the dental epithelium, together with the steric size of the tooth germ, were determining factors for the number of invaginations. Our theoretical results provide a new hypothesis to explain the histological features of the tooth germ. PMID:26188369

  18. Human germ cell differentiation from fetal- and adult-derived induced pluripotent stem cells

    PubMed Central

    Panula, Sarita; Medrano, Jose V.; Kee, Kehkooi; Bergström, Rosita; Nguyen, Ha Nam; Byers, Blake; Wilson, Kitchener D.; Wu, Joseph C.; Simon, Carlos; Hovatta, Outi; Reijo Pera, Renee A.

    2011-01-01

    Historically, our understanding of molecular genetic aspects of human germ cell development has been limited, at least in part due to inaccessibility of early stages of human development to experimentation. However, the derivation of pluripotent stem cells may provide the necessary human genetic system to study germ cell development. In this study, we compared the potential of human induced pluripotent stem cells (iPSCs), derived from adult and fetal somatic cells to form primordial and meiotic germ cells, relative to human embryonic stem cells. We found that ?5% of human iPSCs differentiated to primordial germ cells (PGCs) following induction with bone morphogenetic proteins. Furthermore, we observed that PGCs expressed green fluorescent protein from a germ cell-specific reporter and were enriched for the expression of endogenous germ cell-specific proteins and mRNAs. In response to the overexpression of intrinsic regulators, we also observed that iPSCs formed meiotic cells with extensive synaptonemal complexes and post-meiotic haploid cells with a similar pattern of ACROSIN staining as observed in human spermatids. These results indicate that human iPSCs derived from reprogramming of adult somatic cells can form germline cells. This system may provide a useful model for molecular genetic studies of human germline formation and pathology and a novel platform for clinical studies and potential therapeutical applications. PMID:21131292

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

    PubMed

    González, Raquel; Dobrinski, Ina

    2015-01-01

    Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis and essential to maintain the continuous production of spermatozoa after the onset of puberty in the male. The study of the male germ line is important for understanding the process of spermatogenesis, unravelling mechanisms of stemness maintenance, cell differentiation, and cell-to-cell interactions. The transplantation of SSCs can contribute to the preservation of the genome of valuable individuals in assisted reproduction programs. In addition to the importance of SSCs for male fertility, their study has recently stimulated interest in the generation of genetically modified animals because manipulations of the male germ line at the SSC stage will be maintained in the long term and transmitted to the offspring. Studies performed mainly in the mouse model have laid the groundwork for facilitating advancements in the field of male germ line biology, but more progress is needed in nonrodent species in order to translate the technology to the agricultural and biomedical fields. The lack of reliable markers for isolating germ cells from testicular somatic cells and the lack of knowledge of the requirements for germ cell maintenance have precluded their long-term maintenance in domestic animals. Nevertheless, some progress has been made. In this review, we will focus on the state of the art in the isolation, characterization, culture, and manipulation of SSCs and the use of germ cell transplantation in domestic animals. PMID:25991701

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

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    We provide the first systematic description of germ cell development with molecular markers in a myriapod, the centipede Strigamia maritima. By examining the expression of Strigamia vasa and nanos orthologues, we find that the primordial germ cells are specified from at least the blastoderm stage. This is a much earlier embryonic stage than previously described for centipedes, or any other member of the Myriapoda. Using these genes as markers, and taking advantage of the developmental synchrony of Strigamia embryos within single clutches, we are able to track the development of the germ cells throughout embryogenesis. We find that the germ cells accumulate at the blastopore; that the cells do not internalize through the hindgut, but rather through the closing blastopore; and that the cells undergo a long-range migration to the embryonic gonad. This is the first evidence for primordial germ cells displaying these behaviours in any myriapod. The myriapods are a phylogenetically important group in the arthropod radiation for which relatively little developmental data is currently available. Our study provides valuable comparative data that complements the growing number of studies in insects, crustaceans and chelicerates, and is important for the correct reconstruction of ancestral states and a fuller understanding of how germ cell development has evolved in different arthropod lineages. PMID:24930702

  1. 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

  2. NANOG promoter methylation and expression correlation during normal and malignant human germ cell development

    PubMed Central

    Nettersheim, Daniel; Bierman, Katharina; Gillis, Ad JM; Steger, Klaus; Looijenga, Leendert HJ

    2011-01-01

    Testicular germ cell tumors are the most frequent malignant tumors in young Caucasian males, with increasing incidence. The actual model of tumorigenesis is based on the theory that a block in maturation of fetal germ cells lead to formation of the intratubular germ cell neoplasia unclassified. Early fetal germ cells and undifferentiated germ cell tumors express pluripotency markers such as the transcription factor NANOG. It has been demonstrated that epigenetic modifications, such as promoter DNA methylation, are able to silence gene expression in normal and cancer cells. Here we show that OCT3/4-SOX2 mediated expression of NANOG can be silenced by methylation of promoter CpG-sites. We found that global methylation of DNA decreased from fetal spermatogonia to mature sperm. In contrast, CpGs in the NANOG promoter were found hypomethylated in spermatogonia and hypermethylated in sperm. This selective repression might reflect the cells need to suppress pluripotency in order to prevent malignant transformation. Finally, methylation of CpGs in the NANOG promoter in germ cell tumors and derived cell lines correlated to differentiation state. PMID:20930529

  3. Fenvalerate induces germ cell apoptosis in mouse testes through the Fas/FasL signaling pathway.

    PubMed

    Zhao, Xian-Feng; Wang, Qun; Ji, Yan-Li; Wang, Hua; Liu, Ping; Zhang, Cheng; Zhang, Ying; Xu, De-Xiang

    2011-09-01

    Fenvalerate has a potentially adverse effect on male reproduction and spermatogenesis, whereas the precise mechanism remains obscure. The present study investigated the effects of fenvalerate on germ cell apoptosis in testes. Adult male mice were administered with fenvalerate (15 or 60 mg/kg) by gavage for 28 days. Germ cell apoptosis was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). The number of TUNEL+ germ cells per tubule and the percentage of tubules with TUNEL+ germ cells were significantly increased in testes of mice treated with fenvalerate in a dose-dependent manner. TUNEL+ germ cells were observed mainly in stages VII-VIII and also stages IX-XII seminiferous tubules in testes. Additional experiments showed that fenvalerate increased the level of active caspase-8 and caspase-3 in testes. In addition, fenvalerate upregulated the expression of Fas and FasL in testes. No significant difference on the expression of Bcl-2 and Bax in testes was observed between fenvalerate-treated mice and controls. Fenvalerate did not affect the leakage of cytochrome c from mitochondria into cytoplasm. In addition, fenvalerate did not cause the activation of caspase-9 in testes. Taken together, these results suggest that fenvalerate induces germ cell apoptosis in testes through the Fas/FasL signaling pathway. PMID:21279716

  4. METT-10, A Putative Methyltransferase, Inhibits Germ Cell Proliferative Fate in Caenorhabditis elegans

    PubMed Central

    Dorsett, Maia; Westlund, Bethany; Schedl, Tim

    2009-01-01

    Germ-line stem cells are unique because they either self-renew through mitosis or, at a certain frequency, switch to meiosis and produce gametes. The switch from proliferation to meiosis is tightly regulated, and aberrations in switching result in either too little or too much proliferation. To understand the genetic basis of this regulation, we characterized loss-of-function mutations and a novel tumorous allele of Caenorhabditis elegans mett-10, which encodes a conserved putative methyltransferase. We show that METT-10 is a nuclear protein that acts in the germ line to inhibit the specification of germ-cell proliferative fate. METT-10 also promotes vulva, somatic gonad, and embryo development and ensures meiotic development of those germ cells that do differentiate. In addition, phenotypic analysis of a mett-10 null allele reveals that METT-10 enables mitotic cell cycle progression. The finding that METT-10 functions to inhibit germ-cell proliferative fate, despite promoting mitotic cell cycle progression of those germ cells that do proliferate, separates the specification of proliferative fate from its execution. PMID:19596901

  5. The transcriptional repressor Blimp-1 acts downstream of BMP signaling to generate primordial germ cells in the cricket Gryllus bimaculatus.

    PubMed

    Nakamura, Taro; Extavour, Cassandra G

    2016-01-15

    Segregation of the germ line from the soma is an essential event for transmission of genetic information across generations in all sexually reproducing animals. Although some well-studied systems such as Drosophila and Xenopus use maternally inherited germ determinants to specify germ cells, most animals, including mice, appear to utilize zygotic inductive cell signals to specify germ cells during later embryogenesis. Such inductive germ cell specification is thought to be an ancestral trait of Bilateria, but major questions remain as to the nature of an ancestral mechanism to induce germ cells, and how that mechanism evolved. We previously reported that BMP signaling-based germ cell induction is conserved in both the mouse Mus musculus and the cricket Gryllus bimaculatus, which is an emerging model organism for functional studies of induction-based germ cell formation. In order to gain further insight into the functional evolution of germ cell specification, here we examined the Gryllus ortholog of the transcription factor Blimp-1 (also known as Prdm1), which is a widely conserved bilaterian gene known to play a crucial role in the specification of germ cells in mice. Our functional analyses of the Gryllus Blimp-1 ortholog revealed that it is essential for Gryllus primordial germ cell development, and is regulated by upstream input from the BMP signaling pathway. This functional conservation of the epistatic relationship between BMP signaling and Blimp-1 in inductive germ cell specification between mouse and cricket supports the hypothesis that this molecular mechanism regulated primordial germ cell specification in a last common bilaterian ancestor. PMID:26786211

  6. Primary Hyperparathyroidism

    MedlinePLUS

    Fact Sheet Primary Hyperparathyroidism What is PRIMARY HYPERPARATH YROIDIS M? The body’s parathyroid glands—four pea-sized glands in the neck—produce parathyroid hormone (PTH). Primary hyperparathyroidism (PHPT) is ...

  7. Primary Syphilis

    MedlinePLUS

    ... and rashes clinical tools newsletter | contact Share | Primary Syphilis Information for adults A A A This image ... ulcer with a red base, typical of primary syphilis. Overview Primary syphilis is a disease caused by ...

  8. Fat absorption in germ-free and conventional rats artificially deprived of bile secretion.

    PubMed

    Demarne, Y; Corring, T; Pihet, A; Sacquet, E

    1982-01-01

    Bile duct ligation was performed in germ-free and conventional rats in order to study the effects of bile deprivation on the absorption of dietary lipids and the excretion of faecal lipids in the presence or the absence of gastrointestinal flora. The main consequence of bile duct ligation in conventional rats was decrease of about 50% in the apparent absorption of dietary lipids (peanut oil). In germ-free rats, absorption decreased by only about 25%. In conventional as well as in germ-free controls, faecal lipids were mainly excreted as compounds directly soluble in organic solvents that is, free fatty acids, triglycerides, partial glycerides, cholesterol, cholesterol esters. Deprivation of bile secretion significantly increased the faecal excretion of 'insoluble' compounds-that is, calcium soaps-both in germ-free and conventional rats. Free fatty acids and sterol esters were the two main class of soluble faecal lipids both in germ-free and conventional rats deprived of bile secretion. Faecal excretion of triglycerides remained low in germ-free as well as in conventional animals. No significant difference of fatty acid absorption was observed between germ-free and conventional controls. Deprivation of bile secretion resulted in a significant decrease in the absorption of all fatty acids in germ-free as well as in conventional animals. However, the decrease was larger for saturated fatty acids-that is, 16:0 or 18:0- than for unsaturated fatty acids-that is, 18:1 or 18:2. The absorption of all fatty acids, except linoleic acid (18:2), was significantly lower in conventional rats artificially deprived of bile secretion than in their germ-free counterparts. Evidence was given for a negative digestive balance of stearic acid (18:0) in bile deprived conventional animals. This observation was correlated with a very efficient biohydrogenation of dietary unsaturated fatty acids as revealed by radio gas chromatography of faecal acids in bile deprived conventional rats fed a diet containing 1-14C oleic acid (18:1) as homogeneous triglycerides. Nevertheless, biohydrogenation of unsaturated dietary fatty acids by the gastrointestinal flora was not considered to be the only factor involved in the origin of the difference of fat absorption between bile deprived germ-free and conventional animals. PMID:7056496

  9. Fat absorption in germ-free and conventional rats artificially deprived of bile secretion.

    PubMed Central

    Demarne, Y; Corring, T; Pihet, A; Sacquet, E

    1982-01-01

    Bile duct ligation was performed in germ-free and conventional rats in order to study the effects of bile deprivation on the absorption of dietary lipids and the excretion of faecal lipids in the presence or the absence of gastrointestinal flora. The main consequence of bile duct ligation in conventional rats was decrease of about 50% in the apparent absorption of dietary lipids (peanut oil). In germ-free rats, absorption decreased by only about 25%.In conventional as well as in germ-free controls, faecal lipids were mainly excreted as compounds directly soluble in organic solvents that is, free fatty acids, triglycerides, partial glycerides, cholesterol, cholesterol esters. Deprivation of bile secretion significantly increased the faecal excretion of 'insoluble' compounds-that is, calcium soaps-both in germ-free and conventional rats. Free fatty acids and sterol esters were the two main class of soluble faecal lipids both in germ-free and conventional rats deprived of bile secretion. Faecal excretion of triglycerides remained low in germ-free as well as in conventional animals. No significant difference of fatty acid absorption was observed between germ-free and conventional controls. Deprivation of bile secretion resulted in a significant decrease in the absorption of all fatty acids in germ-free as well as in conventional animals. However, the decrease was larger for saturated fatty acids-that is, 16:0 or 18:0- than for unsaturated fatty acids-that is, 18:1 or 18:2. The absorption of all fatty acids, except linoleic acid (18:2), was significantly lower in conventional rats artificially deprived of bile secretion than in their germ-free counterparts. Evidence was given for a negative digestive balance of stearic acid (18:0) in bile deprived conventional animals. This observation was correlated with a very efficient biohydrogenation of dietary unsaturated fatty acids as revealed by radio gas chromatography of faecal acids in bile deprived conventional rats fed a diet containing 1-14C oleic acid (18:1) as homogeneous triglycerides. Nevertheless, biohydrogenation of unsaturated dietary fatty acids by the gastrointestinal flora was not considered to be the only factor involved in the origin of the difference of fat absorption between bile deprived germ-free and conventional animals. PMID:7056496

  10. Time series analysis supporting the hypothesis that enhanced cosmic radiation during germ cell formation can increase breast cancer mortality in germ cell cohorts

    NASA Astrophysics Data System (ADS)

    Juckett, D. A.; Rosenberg, Barnett

    Techniques from cancer epidemiology and time series analysis were used to explore the hypothesis that cosmic radiation can induce germ cell changes leading to increases in future breast cancer mortality. A birth cohort time series for female breast cancer mortality was obtained using a model-independent, age-period-cohort analysis on age-specific mortality data for 1940-1990. The birth cohort series contained several oscillatory components, which were isolated and compared to the corresponding frequency components of a cosmic ray surrogate time series - Greenland ice-core 10Be concentrations. A technique, referred to as component wave-train alignment, was used to show that the breast cancer and cosmic ray oscillations were phase-locked approx. 25 years before the time of birth. This is consistent with the time of germ cell formation, which occurs during the fetal development stage of the preceding generation. Evidence is presented that the observable oscillations in the birth cohort series were residues of oscillations of much larger amplitude in the germ cell cohort, which were attenuated by the effect of the broad maternal age distribution. It is predicted that a minimum of 50% of breast cancer risk is associated with germ cell damage by cosmic radiation (priming event), which leads to the development of individuals with a higher risk of breast cancer. It is proposed that the priming event, by preceding other steps of carcinogenesis, works in concert with risk factor exposure during life. The priming event is consistent with epigenetic changes such as imprinting.

  11. In vitro production of haploid sperm cells from male germ cells of foetal cattle.

    PubMed

    Dong, Wu-Zi; Hua, Jin-Lian; Shen, Wen-Zheng; Dou, Zhong-Ying

    2010-04-01

    The purpose of this study was to isolate the foetal cattle male germ cells (mGCs) and then induce them into sperm cells. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the vasa and the c-kit positive cells were 95.34+/-2.25% and 53.3+/-1.03% by using flow cytometry analysis (FCA), respectively. In feeder-free culture system, the half-suspending cells appeared and formed a 16-cell rosary in medium after the mGCs were cultured for 6-8 days. On immunocytochemical staining during the second passage, some single cells adhering to the plate appeared to be both Oct-4 and alpha6-integrin positive. During the third passage, the mGCs were induced for 48 h by retinol acid (RA) on Sertoli cell-feeder layer, followed by 5-7 days culture in an RA-free medium. Some elongated sperm-like cells appeared in the medium at this stage. We found that the most effective concentration of RA for the inducement was 10(-7)moll(-1) (P<0.01). The haploid cells in suspension were identified by FCA. The elongated sperm-like cells showed proacrosome-like structure and the flagellum with fibre construct under electron microscopy. The mRNA of outer dense fibre-3 (ODF-3) and transcription protein-1 (TP-1) could be detected in the suspended cells by using reverse transcription polymerase chain reaction (RT-PCR). About 23.1% bovine oocytes could be activated to perform cleavage by intracytoplasmic injection with the sperm-like cells, but embryos did not further develop. Our investigation further demonstrated that foetal cattle mGCs could be induced in vitro into haploid sperm in the short term. PMID:19632794

  12. Global deletion of Trp53 reverts ovarian tumor phenotype of the germ cell-deficient white spotting variant (Wv) mice.

    PubMed

    Cai, Kathy Qi; Wang, Ying; Smith, Elizabeth R; Smedberg, Jennifer L; Yang, Dong-Hua; Yang, Wan-Lin; Xu, Xiang-Xi

    2015-01-01

    White spotting variant (Wv) mice are spontaneous mutants attributed to a point mutation in the c-Kit gene, which reduces the tyrosine kinase activity to around 1% and affects the development of melanocytes, mast cells, and germ cells. Homozygous mutant mice are sterile but can live nearly a normal life span. The female Wv mice have a greatly reduced ovarian germ cell and follicle reserve at birth, and the remaining follicles are largely depleted soon after the females reach reproductive stage at around 7 weeks of age. Consequently, ovarian epithelial tumors develop in 100% of Wv females by 3 to 4 months of age. These tumors, called tubular adenomas, are benign but can become invasive in older Wv mice. We tested if additional genetic mutation(s) could convert the benign ovarian epithelial tumors to malignant tumors by crossing the Wv mutant into the Trp53 knockout background. Surprisingly, we found that global deletion of Trp53 suppressed the development of ovarian tubular adenomas in Wv mice. The ovaries of Wv/Wv; Trp53 (-/-) mice were covered by a single layer of surface epithelium and lacked excessive epithelial proliferation. Rather, the ovaries contained a small number of follicles. The presence of ovarian follicles and granulosa cells, as indicated by Pgc7 and inhibin-alpha expression, correlated with the absence of epithelial lesions. A reduction of Pten gene dosage, as in Wv/Wv; Pten (+/-) mice, produced a similar, though less dramatic, phenotype. We conclude that deletion of Trp53 prolongs the survival of ovarian follicles in Wv mice and consequently prevents the proliferation of ovarian epithelial cells and development of ovarian tubular adenomas. The results suggest that various cell types within the ovary communicate and mutually modulate, and an intact tissue environment is required to ensure homeostasis of ovarian surface epithelial cells. Especially, the current finding emphasizes the importance of ovarian follicles in suppressing the hyperplastic growth of ovarian epithelial cells, dominating over the loss of p53. PMID:25622902

  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. Novel somatic and germline mutations in intracranial germ cell tumors

    PubMed Central

    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.

    2015-01-01

    Intracranial germ cell tumors (IGCTs) are a group of rare heterogeneous brain tumors which are clinically and histologically similar to the more common gonadal GCTs. IGCTs show great variation in their geographic and gender distribution, histological composition and treatment outcomes. The incidence of IGCTs is historically 5–8 fold greater in Japan and other East Asian countries than in Western countries1 with peak incidence near the time of puberty2. About half of the tumors are located in the pineal region. The male-to-female incidence ratio is approximately 3–4:1 overall but even higher for tumors located in the pineal region3. Due to the scarcity of tumor specimens available for research, little is currently known about this rare disease. Here we report the analysis of 62 cases by next generation sequencing, SNP array and expression array. We find the KIT/RAS signaling pathway frequently mutated in over 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 gain 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 corepressor and tumor suppressor. We report significant enrichment of novel and rare germline variants in JMJD1C, a histone demethylase and 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

  15. 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

  16. Understanding germ-line mutations in BRCA1.

    PubMed

    Szabo, Csilla I; Worley, Terri; Monteiro, Alvaro N A

    2004-06-01

    Germ-line mutations in BRCA1 account for the majority of familial breast and ovarian cancer cases and development of cancer in individuals who carry such mutations requires somatic inactivation of the normal allele. BRCA1 is highly polymorphic with more than 1,200 distinct documented variants. Approximately 70% of reported variants lead to absence of full-length BRCA1 protein, through loss of expression or protein truncation, and are suspected to predispose to cancer. These include regulatory mutations, splice site alterations, large rearrangements, large and small deletions or insertions, and nonsense mutations. However, characterizing the remaining missense alterations as either deleterious (cancer-associated mutations) or neutral variants is more complex, as the functional significance of the respective amino acid substitution is not straightforward to evaluate. In addition, many missense variants have been identified only once in defined ethnic groups and represent alleles with very low frequency. Most often, little information is available about segregation of the variant with disease in families, and assessment of disease risk for low frequency alleles through association studies is problematic, requiring a large number of samples stratified and matched by ethnicity. The fact that a significant proportion of BRCA1 variants remain unclassified represents a gap in risk assessment, such that individuals undergoing genetic testing will receive noninformative test results. An approach for assessing the potential clinical significance of missense variants is to combine available genetic data with functional and structural studies. Here we review the available information on BRCA1 variants and explore ways in which we can analyze unclassified variants. PMID:15254424

  17. Pathogenesis of germ cell neoplasia in testicular dysgenesis and disorders of sex development.

    PubMed

    Jørgensen, Anne; Lindhardt Johansen, Marie; Juul, Anders; Skakkebaek, Niels E; Main, Katharina M; Rajpert-De Meyts, Ewa

    2015-09-01

    Development of human gonads is a sex-dimorphic process which evolved to produce sex-specific types of germ cells. The process of gonadal sex differentiation is directed by the action of the somatic cells and ultimately results in germ cells differentiating to become functional gametes through spermatogenesis or oogenesis. This tightly controlled process depends on the proper sequential expression of many genes and signalling pathways. Disturbances of this process can be manifested as a large spectrum of disorders, ranging from severe disorders of sex development (DSD) to - in the genetic male - mild reproductive problems within the testicular dysgenesis syndrome (TDS), with large overlap between the syndromes. These disorders carry an increased but variable risk of germ cell neoplasia. In this review, we discuss the pathogenesis of germ cell neoplasia associated with gonadal dysgenesis, especially in individuals with 46,XY DSD. We summarise knowledge concerning development and sex differentiation of human gonads, with focus on sex-dimorphic steps of germ cell maturation, including meiosis. We also briefly outline the histopathology of germ cell neoplasia in situ (GCNIS) and gonadoblastoma (GDB), which are essentially the same precursor lesion but with different morphological structure dependent upon the masculinisation of the somatic niche. To assess the risk of germ cell neoplasia in different types of DSD, we have performed a PubMed search and provide here a synthesis of the evidence from studies published since 2006. We present a model for pathogenesis of GCNIS/GDB in TDS/DSD, with the risk of malignancy determined by the presence of the testis-inducing Y chromosome and the degree of masculinisation. The associations between phenotype and the risk of neoplasia are likely further modulated in each individual by the constellation of the gene polymorphisms and environmental factors. PMID:26410164

  18. Male Differentiation of Germ Cells Induced by Embryonic Age-Specific Sertoli Cells in Mice1

    PubMed Central

    Ohta, Kohei; Yamamoto, Miyuki; Lin, Yanling; Hogg, Nathanael; Akiyama, Haruhiko; Behringer, Richard R.; Yamazaki, Yukiko

    2012-01-01

    ABSTRACT Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells. PMID:22262692

  19. Male differentiation of germ cells induced by embryonic age-specific Sertoli cells in mice.

    PubMed

    Ohta, Kohei; Yamamoto, Miyuki; Lin, Yanling; Hogg, Nathanael; Akiyama, Haruhiko; Behringer, Richard R; Yamazaki, Yukiko

    2012-04-01

    Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells. PMID:22262692

  20. Model of the biotic cycle "plants germs - microorganisms" by affect heavy metal salts

    NASA Astrophysics Data System (ADS)

    Pisman, Tamara

    The growth of wheat germ roots exposed to heavy metal salts (ZnSO4) was studied experimentally and theoretically. During the experiment the plant seeds were preliminarily treated with an experimental microbial association. As a result, data were obtained about the decrease of the inhibiting effect of zinc on the growth of wheat germ roots where the seeds had been treated with the microbial association. To understand such effect, calculations were made to reveal the specific growth rate of a germ root depending on the inhibitor concentration with and without microorganism association treatment. It was shown that in case with the wheat germ roots the seeds of which had been treated with the microorganisms the inhibition constant (kI = 45 MPC (Maximum Permissible Concentration) was higher than in the case with the roots growing out of the seeds that hadn't been treated with the microorganisms (kI = 32 MPC). One of possible reasons for the decrease of growth inhibition of wheat germ roots by zinc salt is the protective function of microorganism's treatment of the seeds. To verify and confirm the experimental results, a mathematical model was created imitating the interaction between wheat germ roots and microbial association exposed to an inhibitor. Investigation of the model proved that the microbial association has a positive effect on the growth of wheat germ roots exposed to an inhibitor. The experimental and theoretical results agreed quantitatively. It was found out that the increase of the inhibitor concentration led to the effect of maximum relief of zinc inhibiting impact. The work is supported by grants Yenissei 07-04-96806.

  1. 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

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

    PubMed Central

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

    2015-01-01

    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 Cu2+-chelating activity compared to WGE. WGE and F-WGE treatment at doses between 10 and 400 μg/mL did not affect the viability of HepG2 and 3T3-L1 cells. Intracellular ROS levels from Cu2+-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 μM Fe2+ treatment, but the accumulation was strongly inhibited by 100 μg/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

  3. 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 μg/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 μM Fe(2+) treatment, but the accumulation was strongly inhibited by 100 μg/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

  4. Size of the Optic Nerve Head and Its Relationship with the Thickness of the Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Patients with Primary Open Angle Glaucoma

    PubMed Central

    Enomoto, Nobuko; Anraku, Ayako; Ishida, Kyoko; Takeyama, Asuka; Yagi, Fumihiko; Tomita, Goji

    2015-01-01

    Purpose. To evaluate the relationships among the optic nerve head (ONH) area, macular ganglion cell complex (mGCC) thickness, circumpapillary retinal nerve fiber layer (cpRNFL) thickness, and visual field defects in patients with primary open angle glaucoma (POAG). Methods. This retrospective study included 90 eyes of 90 patients with POAG. The ONH area, rim area, mGCC thickness, and cpRNFL thickness were measured using optical coherence tomography. Mean deviation (MD) was measured using standard automated perimetry. The relationships among clinical factors including age, refraction, the ONH area, the rim area, the mGCC thickness, the cpRNFL thickness, and MD were evaluated using correlation coefficients and multiple regression analyses. Results. The significant correlation of the ONH area with refraction (r = 0.362, P < 0.001), the mGCC thickness (r = 0.225, P = 0.033), and the cpRNFL thickness (r = 0.253, P = 0.016) was found. Multiple regression analysis showed that the ONH area, rim area, and MD were selected as significant contributing factors to explain the mGCC thickness and cpRNFL thickness. No factor was selected to explain MD. Conclusions. The ONH area, in other words, the disc size itself may affect the mGCC thickness and cpRNFL thickness in POAG patients. PMID:26339503

  5. Descriptive epidemiology of central nervous system germ cell tumors: nonpineal analysis†

    PubMed Central

    Villano, J. Lee; Virk, Irim Y.; Ramirez, Vanessa; Propp, Jennifer M.; Engelhard, Herbert H.; McCarthy, Bridget J.

    2010-01-01

    Central nervous system (CNS) germ cell tumors (GCT) have not been epidemiologically well described. Our study describes 2 population-based series of nonpineal CNS GCT. Data on all primary (malignant and nonmalignant) CNS (ICD-O-3 sites: C70.0–C72.9, C75.1–C75.3) GCT diagnosed between 2000 and 2004 from the Central Brain Tumor Registry of the United States (CBTRUS) and on all malignant GCT diagnosed between 1992 and 2005 from the Surveillance, Epidemiology, and End Results (SEER) were analyzed. Of 234 nonpineal GCT in CBTRUS, the most common site was brain, NOS (31.6%). Males had a greater frequency (59.7%) than females (40.3%). However, by age group, the male-to-female incidence rate ratio (IRR) differed: children (0–14 years) had an IRR of 1.1, young adults (15–29 years) an IRR of 2.3, and adults (aged 30+) an IRR of 1.0. For children and young adults, most tumors were malignant (86.8% and 89.0%, respectively), whereas for adults, more than half were nonmalignant (56.8%). Germinoma was the most frequent diagnosis (61.5%). In SEER, the frequency of malignant GCT in the CNS (2.5%) was greater than that in the mediastinum (2.1%). Of 408 malignant CNS GCT, 216 (52.9%) were nonpineal. The male-to-female IRR was 1.5. Overall relative survival for nonpineal CNS malignant GCT was 85.3% at 2 years, 77.3% at 5 years, and 67.6% at 10 years. Previous studies of GCT that have not stratified by site have suggested greater gender disparity. Nonpineal CNS GCT show no significant gender preference, yet have outcomes similar to pineal GCT. PMID:20167813

  6. Familial testicular germ cell tumors (FTGCT) - overview of a multidisciplinary etiologic study.

    PubMed

    Greene, M H; Mai, P L; Loud, J T; Pathak, A; Peters, J A; Mirabello, L; McMaster, M L; Rosenberg, P; Stewart, D R

    2015-01-01

    This Review summarizes the cumulative results of the National Cancer Institute Clinical Genetics Branch Multidisciplinary Etiologic Study of Familial Testicular Germ Cell Tumors (FTGCT). Initiated 12 years ago, this protocol enrolled 724 subjects from 147 unrelated families with either ?2 affected men (n = 90) with TGCT or a proband with bilateral TGCT and a negative family history for this cancer (n = 57). Data were collected directly from 162 subjects evaluated at the NIH Clinical Center, and 562 subjects provided information from their home communities (Field Cohort). The primary study aims included (i) ascertaining, enrolling eligible FTGCT kindred, (ii) characterizing the clinical phenotype of multiple-case families, (iii) identifying the underlying genetic mechanism for TGCT susceptibility in families, (iv) evaluating counseling, psychosocial, and behavioral issues resulting from membership in an FTGCT family, and (v) creating an annotated biospecimen repository to permit subsequent translational research studies. Noteworthy findings include (i) documenting the epidemiologic similarities between familial and sporadic TGCT, (ii) demonstrating significantly younger age-at-diagnosis for familial vs. sporadic TGCT, (iii) absence of a dysmorphic phenotype in affected family members, (iv) shifting the focus of gene discovery from a search for rare, highly penetrant susceptibility variants to the hypothesis that multiple, more common, lower penetrance genes underlie TGCT genetic risk, (v) implicating testicular microlithiasis in FTGCT risk, and (vi) observing that aberrant methylation may contribute to FTGCT risk. A clinically based, biospecimen-intensive, multidisciplinary research strategy has provided novel, valuable insights into the etiology of FTGCT, and created a research resource which will support FTGCT clinical and laboratory studies for years to come. PMID:25303766

  7. Production of chicken progeny (Gallus gallus domesticus) from interspecies germline chimeric duck (Anas domesticus) by primordial germ cell transfer.

    PubMed

    Liu, Chunhai; Khazanehdari, Kamal A; Baskar, Vijaya; Saleem, Shazia; Kinne, Joerg; Wernery, Ulrich; Chang, Il-Kuk

    2012-04-01

    The present study aimed to investigate the differentiation of chicken (Gallus gallus domesticus) primordial germ cells (PGCs) in duck (Anas domesticus) gonads. Chimeric ducks were produced by transferring chicken PGCs into duck embryos. Transfer of 200 and 400 PGCs resulted in the detection of a total number of 63.0 ± 54.3 and 116.8 ± 47.1 chicken PGCs in the gonads of 7-day-old duck embryos, respectively. The chimeric rate of ducks prior to hatching was 52.9% and 90.9%, respectively. Chicken germ cells were assessed in the gonad of chimeric ducks with chicken-specific DNA probes. Chicken spermatogonia were detected in the seminiferous tubules of duck testis. Chicken oogonia, primitive and primary follicles, and chicken-derived oocytes were also found in the ovaries of chimeric ducks, indicating that chicken PGCs are able to migrate, proliferate, and differentiate in duck ovaries and participate in the progression of duck ovarian folliculogenesis. Chicken DNA was detected using PCR from the semen of chimeric ducks. A total number of 1057 chicken eggs were laid by Barred Rock hens after they were inseminated with chimeric duck semen, of which four chicken offspring hatched and one chicken embryo did not hatch. Female chimeric ducks were inseminated with chicken semen; however, no fertile eggs were obtained. In conclusion, these results demonstrated that chicken PGCs could interact with duck germinal epithelium and complete spermatogenesis and eventually give rise to functional sperm. The PGC-mediated germline chimera technology may provide a novel system for conserving endangered avian species. PMID:22190706

  8. Germ cell differentiation in the marmoset (Callithrix jacchus) during fetal and neonatal life closely parallels that in the human

    PubMed Central

    Mitchell, R.T.; Cowan, G.; Morris, K.D.; Anderson, R.A.; Fraser, H.M.; Mckenzie, K.J.; Wallace, W.H.B.; Kelnar, C.J.H.; Saunders, P.T.K.; Sharpe, R.M.

    2008-01-01

    BACKGROUND Testicular germ cell tumours (TGCT) are thought to originate from fetal germ cells that fail to differentiate normally, but no animal model for these events has been described. We evaluated the marmoset (Callithrix jacchus) as a model by comparing perinatal germ cell differentiation with that in humans. METHODS Immunohistochemical profiling was used to investigate germ cell differentiation (OCT4, NANOG, AP-2?, MAGE-A4, VASA, NANOS-1) and proliferation (Ki67) in fetal and neonatal marmoset testes in comparison with the human and, to a lesser extent, the rat. RESULTS In marmosets and humans, differentiation of gonocytes into spermatogonia is associated with the gradual loss of pluripotency markers such as OCT4 and NANOG, and the expression of germ cell-specific proteins such as VASA. This differentiation occurs asynchronously within individual cords during fetal and early postnatal life. This contrasts with rapid and synchronous germ cell differentiation within and between cords in the rat. Similarly, germ cell proliferation in the marmoset and human occurs throughout perinatal life, in contrast to rats in which proliferation ceases during this period. CONCLUSIONS The marmoset provides a good model for normal human germ cell differentiation and proliferation. The perinatal marmoset may be a useful model in which to establish factors that lead to failure of normal germ cell differentiation and the origins of TGCT. PMID:18694875

  9. AIP1-mediated actin disassembly is required for postnatal germ cell migration and spermatogonial stem cell niche establishment.

    PubMed

    Xu, J; Wan, P; Wang, M; Zhang, J; Gao, X; Hu, B; Han, J; Chen, L; Sun, K; Wu, J; Wu, X; Huang, X; Chen, J

    2015-01-01

    In mammals, spermatogonial stem cells (SSCs) arise from early germ cells called gonocytes, which are derived from primordial germ cells during embryogenesis and remain quiescent until birth. After birth, these germ cells migrate from the center of testicular cord, through Sertoli cells, and toward the basement membrane to form the SSC pool and establish the SSC niche architecture. However, molecular mechanisms underlying germ cell migration and niche establishment are largely unknown. Here, we show that the actin disassembly factor actin interacting protein 1 (AIP1) is required in both germ cells and Sertoli cells to regulate this process. Germ cell-specific or Sertoli cell-specific deletion of Aip1 gene each led to significant defects in germ cell migration after postnatal day 4 or 5, accompanied by elevated levels of actin filaments (F-actin) in the affected cells. Furthermore, our data demonstrated that interaction between germ cells and Sertoli cells, likely through E-cadherin-mediated cell adhesion, is critical for germ cells' migration toward the basement membrane. At last, Aip1 deletion in Sertoli cells decreased SSC self-renewal, increased spermatogonial differentiation, but did not affect the expression and secretion levels of growth factors, suggesting that the disruption of SSC function results from architectural changes in the postnatal niche. PMID:26181199

  10. AIP1-mediated actin disassembly is required for postnatal germ cell migration and spermatogonial stem cell niche establishment

    PubMed Central

    Xu, J; Wan, P; Wang, M; Zhang, J; Gao, X; Hu, B; Han, J; Chen, L; Sun, K; Wu, J; Wu, X; Huang, X; Chen, J

    2015-01-01

    In mammals, spermatogonial stem cells (SSCs) arise from early germ cells called gonocytes, which are derived from primordial germ cells during embryogenesis and remain quiescent until birth. After birth, these germ cells migrate from the center of testicular cord, through Sertoli cells, and toward the basement membrane to form the SSC pool and establish the SSC niche architecture. However, molecular mechanisms underlying germ cell migration and niche establishment are largely unknown. Here, we show that the actin disassembly factor actin interacting protein 1 (AIP1) is required in both germ cells and Sertoli cells to regulate this process. Germ cell-specific or Sertoli cell-specific deletion of Aip1 gene each led to significant defects in germ cell migration after postnatal day 4 or 5, accompanied by elevated levels of actin filaments (F-actin) in the affected cells. Furthermore, our data demonstrated that interaction between germ cells and Sertoli cells, likely through E-cadherin-mediated cell adhesion, is critical for germ cells' migration toward the basement membrane. At last, Aip1 deletion in Sertoli cells decreased SSC self-renewal, increased spermatogonial differentiation, but did not affect the expression and secretion levels of growth factors, suggesting that the disruption of SSC function results from architectural changes in the postnatal niche. PMID:26181199

  11. Interaction between DMRT1 function and genetic background modulates signaling and pluripotency to control tumor susceptibility in the fetal germ line

    PubMed Central

    Krentz, Anthony D.; Murphy, Mark W.; Zhang, Teng; Sarver, Aaron L.; Jain, Sanjay; Griswold, Michael D.; Bardwell, Vivian J.; Zarkower, David

    2013-01-01

    Dmrt1(doublesex and mab-3 related transcription factor 1) is a regulator of testis development in vertebrates that has been implicated in testicular germ cell tumors of mouse and human. In the fetal mouse testis Dmrt1 regulates germ cell pluripotency in a strain-dependent manner. Loss of Dmrt1 in 129Sv strain mice results in a >90% incidence of testicular teratomas, tumors consisting cells of multiple germ layers; by contrast, these tumors have never been observed in Dmrt1 mutants of C57BL/6J (B6) or mixed genetic backgrounds. To further investigate the interaction between Dmrt1 and genetic background we compared mRNA expression in wild type and Dmrt1 mutant fetal testes of 129Sv and B6 mice at embryonic day 15.5 (E15.5), prior to overt tumorigenesis. Loss of Dmrt1 caused misexpression of overlapping but distinct sets of mRNAs in the two strains. The mRNAs that were selectively affected included some that changed expression only in one strain or the other and some that changed in both strains but to a greater degree in one versus the other. In particular, loss of Dmrt1 in 129Sv testes caused a more severe failure to silence regulators of pluripotency than in B6 testes. A number of genes misregulated in 129Sv mutant testes also are misregulated in human testicular germ cell tumors (TGCTs), suggesting similar etiology between germ cell tumors in mouse and man. Expression profiling showed that DMRT1 also regulates pluripotency genes in the fetal ovary, although Dmrt1 mutant females do not develop teratomas. Pathway analysis indicated disruption of several signaling pathways in Dmrt1 mutant fetal testes, including Nodal, Notch, and GDNF. We used a Nanos3-cre knock-in allele to perform conditional gene targeting, testing the GDNF coreceptors Gfra1 and Ret for effects on teratoma susceptibility. Conditional deletion of Gfra1 but not Ret in fetal germ cells of animals outcrossed to 129Sv caused a modest but significant elevation in tumor incidence. Despite some variability in genetic background in these crosses, this result is consistent with previous genetic mapping of teratoma susceptibility loci to the region containing Gfra1. Using Nanos3-cre we also uncovered a strong genetic interaction between Dmrt1 and Nanos3, suggesting parallel functions for these two genes in fetal germ cells. Finally, we used chromatin immunoprecipitation (ChIP-seq) analysis to identify a number of potentially direct DMRT1 targets. This analysis suggested that DMRT1 controls pluripotency via transcriptional repression of Esrrb, Nr5a2/Lrh1, and Sox2. Given the strong evidence for involvement of DMRT1 in human TGCT, the downstream genes and pathways identified in this study provide potentially useful candidates for roles in the human disease. PMID:23473982

  12. "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

  13. Mechanism of neutrophil chemiluminescence induced by wheat germ agglutinin: partial characterization of the antigens recognized by wheat germ agglutinin

    SciTech Connect

    Ozaki, Y.; Iwata, J.; Ohashi, T.

    1984-11-01

    Wheat germ agglutinin (WGA) stimulated neutrophils to produce significant levels of luminol-dependent chemiluminescence (CL). Since WGA is known to bind N-acetylglucosamine (GlcNAc) oligomers and N-acetylneuraminic acid (NANA), we attempted to determine which binding property of WGA is essential for induction of CL. The succinylated form of WGA (SuWGA), which is no longer able to bind NANA, was still able to induce CL. N-Acetylglucosamine at a concentration of 20 mmol/L almost completely inhibited WGA-induced CL production by neutrophils, whereas bovine submaxillary gland mucin, a potent blocker of NANA binding of WGA, failed to inhibit CL production. Lectins with the GlcNAc-binding property were examined for their ability to induce CL. Those that have higher valences and have a tendency to bind GlcNAc oligomers in the internal portion of glycoconjugates were able to induce CL, whereas those that have low valences and bind terminal GlcNAc of glycoconjugates failed to induce CL even at high concentrations. Attempts were made to characterize the neutrophil membrane proteins recognized by WGA. Glycoproteins with a molecular weight of 25,000 daltons were identified by a 50 mmol/L GlcNAc elution of WGA gels loaded with /sup 125/I-labeled neutrophil membrane proteins. Elution with 500 mumol/L GlcNAc trimer produced several glycoproteins of different molecular weights in addition to the glycoproteins of 25,000 daltons. /sup 125/I-labeled WGA and SuWGA were used for autoradiographic analysis of cell extracts of the neutrophils separated on sodium dodecyl sulfate polyacrylamide gels. WGA recognized multiple glycoproteins of different molecular weights, whereas SuWGA bound only a few of them. Glycoproteins of 25,000 daltons, probably corresponding to those identified by 50 mmol/L GlcNAc elution, were also recognized.

  14. Gender differences in the induction of chromosomal aberrations and gene mutations in rodent germ cells

    SciTech Connect

    Adler, Ilse-Dore; Carere, Angelo; Eichenlaub-Ritter, Ursula

    2007-05-15

    Germ cell mutagenicity testing provides experimental data to quantify genetic risk for exposed human populations. The majority of tests are performed with exposure of males, and female data are relatively rare. The reason for this paucity lies in the differences between male and female germ cell biology. Male germ cells are produced throughout reproductive life and all developmental stages can be ascertained by appropriate breeding schemes. In contrast, the female germ cell pool is limited, meiosis begins during embryogenesis and oocytes are arrested over long periods of time until maturation processes start for small numbers of oocytes during the oestrus cycle in mature females. The literature data are reviewed to point out possible gender differences of germ cells to exogenous agents such as chemicals or ionizing radiation. From the limited information, it can be concluded that male germ cells are more sensitive than female germ cells to the induction of chromosomal aberrations and gene mutations. However, exceptions are described which shed doubt on the extrapolation of experimental data from male rodents to the genetic risk of the human population. Furthermore, the female genome may be more sensitive to mutation induction during peri-conceptional stages compared to the male genome of the zygote. With few exceptions, germ cell experiments have been carried out under high acute exposure to optimize the effects and to compensate for the limited sample size in animal experiments. Human exposure to environmental agents, on the other hand, is usually chronic and involves low doses. Under these conditions, gender differences may become apparent that have not been studied so far. Additionally, data are reviewed that suggest a false impression of safety when responses are negative under high acute exposure of male rodents while a mutational response is induced by low chronic exposure. The classical (morphological) germ cell mutation tests are not performed anymore because they are animal and time consuming. Nevertheless, information is needed to place genetic risk extrapolations on more solid grounds and thereby to prevent an increased genetic burden to future generations. It is pointed out that modern molecular methodologies are available now to experimentally address the open questions.

  15. Fermentation and costs of fuel ethanol from corn with Quick-Germ process.

    PubMed

    Taylor, F; Mcaloon, A J; Craig, J C; Yang, P; Wahjudi, J; Eckhoff, S R

    2001-04-01

    The Quick-Germ process developed at the University of Illinois at Urbana-Champaign is a way to obtain corn oil, but with lower capital costs than the traditional wet-milling process. Quick-Germ has the potential to increase the coproduct credits and profitability of the existing dry-grind fuel ethanol process, but the fermentability of the corn remaining after oil recovery has not been tested. Therefore, a series of pilot scale (50 L) fermentations was carefully controlled and monitored with unique methods for standard inoculation and automatic sampling. It was found that the concentration of suspended solids was significantly reduced in the Quick-Germ fermentations. When compared at the same concentration of fermentable sugars, the fermentation rate and yield were not statistically different from controls. When Quick-Germ was integrated into a state-of-the-art dry-grind fuel ethanol process, computer simulation and cost models indicated savings of approx $0.01/L of ethanol ($0.04/gal) with the Quick-Germ process. Additional savings associated with the lower suspended solids could not be quantified and were not included. However, the savings are sensitive to the price of corn oil. PMID:11393355

  16. The Epigenetics of Germ-line Immortality: Lessons from an Elegant Model System

    PubMed Central

    Furuhashi, Hirofumi; Kelly, William G.

    2014-01-01

    Epigenetic mechanisms are thought to help regulate the unique transcription program that is established in germ cell development. During the germline cycle of many organisms, the epigenome undergoes waves of extensive resetting events, while a part of epigenetic modification remains faithful to specific loci. Little is known about the mechanisms underlying these events, how loci are selected for, or avoid, reprogramming, or even why these events are required. In particular, although the significance of genomic imprinting phenomena involving DNA methylation in mammals is now well accepted, the role of histone modification as a transgenerational epigenetic mechanism has been the subject of debate. Such epigenetic mechanisms may help regulate transcription programs and / or the pluripotent status conferred on germ cells, and contribute to germ line continuity across generations. Recent studies provide new evidence for heritability of histone modifications through germ line cells and its potential effects on transcription regulation both in the soma and germ line of subsequent generations. Unraveling transgenerational epigenetic mechanisms involving highly conserved histone modifications in elegant model systems will accelerate the generation of new paradigms and inspire research in a wide variety of fields, including basic developmental studies and clinical stem cell research. PMID:20646025

  17. Molecular events and signalling pathways of male germ cell differentiation in mouse.

    PubMed

    Rossitto, Moïra; Philibert, Pascal; Poulat, Francis; Boizet-Bonhoure, Brigitte

    2015-09-01

    Germ cells, the precursors of gametes, represent a unique cell lineage that is able to differentiate into spermatozoa or oocytes depending on the chromosomal sex of the organism. In the mammalian embryonic gonad, commitment to oogenesis involves pre-meiotic DNA replication and entry into the first meiotic division; whereas, commitment to spermatogenesis involves inhibition of meiotic initiation, suppression of pluripotency, mitotic arrest and expression of specific markers that will control the development of the male germ cells. The crucial decision made by the germ line to commit to either a male or a female fate has been partially explained by genetic and ex vivo studies in mice which have implicated a complex network of regulatory genes, numerous factors and pathways. Besides the reproductive failure that may follow a deregulation of this complex network, the germ cells may, in view of their proliferative and pluripotent nature, act as precursors of potential malignant transformation and as putative targets for exogenous environmental compounds. Our review summarizes and discusses recent developments that have improved our understanding on how germ cell precursors are committed to a male or a female cell fate in the mouse gonad. PMID:26454096

  18. MCM9 deficiency delays primordial germ cell proliferation independent of the ATM pathway.

    PubMed

    Luo, Yunhai; Schimenti, John C

    2015-11-01

    Maintenance of genome integrity is crucial for the germline, and this is reflected by lower mutation rates in gametes than somatic cells. Germ cells at different stages employ different DNA damage response (DDR) mechanisms. In response to certain DNA repair defects, primordial germ cells (PGCs) either undergo apoptosis or delayed proliferation, although little is known about the underlying mechanisms that govern these outcomes. Here, we report genetic studies of DDR pathways that underlie germ cell depletion in mice mutant for minichromosome maintenance 9 (Mcm9), a gene that plays a role in homologous recombination repair (HRR). Germ cell depletion in these mice is a result of reduced PGC numbers both before and after they arrive in the primitive gonads. This reduction was attributable to reduced proliferation, not apoptosis, and this response was independent of ATM-CHK2-TRP53-P21 signaling. This mechanism of PGC depletion differs from that in Fancm mutants, which also display reduced PGC depletion that is partially orchestrated by the ATM-TRP53-P21 pathway. Germ cell depletion in mice doubly deficient for FANCM and MCM9 was additive, indicating that the damage caused by each mutation triggers different DDR pathways to slow the cell cycle as a means to preserve genomic integrity. genesis 53:678-684, 2015. © 2015 Wiley Periodicals, Inc. PMID:26388201

  19. Defective autophagy through epg5 mutation results in failure to reduce germ plasm and mitochondria.

    PubMed

    Herpin, Amaury; Englberger, Eva; Zehner, Mario; Wacker, Robin; Gessler, Manfred; Schartl, Manfred

    2015-10-01

    Autophagy is an evolutionarily conserved catabolic process that transports cytoplasmic components to lysosomes for degradation. In addition to the canonical view of strict stress-response-induced autophagy, selectively programmed autophagy was recently reported in the context of gonad development of flies and worms, where autophagy seems to be necessary for clearance of germ plasm components. Similar functions have not been described in vertebrates. We used the medaka fish to study the role of autophagy in gonad formation and gametogenesis for the first time in a vertebrate organism for which the germ line is specified by germ plasm. Using a transgenic line deficient in the Ol-epg5 gene—a new critical component of the autophagy pathway—we show that such deficiency leads to an impaired autophagic flux, possibly attributed to compromised maturation or processing of the autophagosomes. Ol-epg5 deficiency correlates with selectively impaired spermatogenesis and low allele transmission rates of the mutant allele caused by failure of germ plasm and mitochondria clearance during the process of germ cell specification and in the adult gonads. The mouse epg-5 homolog is similarly expressed in the maturating and adult testes, suggesting an at least partially conserved function of this process during spermatogenesis in vertebrates. PMID:26183773

  20. 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

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

    SciTech Connect

    Fan Jun; Graham, Matthew; Akabane, Hiroto; Richardson, Laura L.; Zhu Guozhang . 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.

  2. 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

    γ-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

  3. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies

    PubMed Central

    Dominguez, Antonia A.; Chiang, H. Rosaria; Sukhwani, Meena; Orwig, Kyle E.; Reijo Pera, Renee A.

    2014-01-01

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood. PMID:25242416

  4. TOPAZ1, a Novel Germ Cell-Specific Expressed Gene Conserved during Evolution across Vertebrates

    PubMed Central

    Baillet, Adrienne; Le Bouffant, Ronan; Volff, Jean Nicolas; Luangpraseuth, Alix; Poumerol, Elodie; Thépot, Dominique; Pailhoux, Eric; Livera, Gabriel; Cotinot, Corinne; Mandon-Pépin, Béatrice

    2011-01-01

    Background We had previously reported that the Suppression Subtractive Hybridization (SSH) approach was relevant for the isolation of new mammalian genes involved in oogenesis and early follicle development. Some of these transcripts might be potential new oocyte and granulosa cell markers. We have now characterized one of them, named TOPAZ1 for the Testis and Ovary-specific PAZ domain gene. Principal Findings Sheep and mouse TOPAZ1 mRNA have 4,803 bp and 4,962 bp open reading frames (20 exons), respectively, and encode putative TOPAZ1 proteins containing 1,600 and 1653 amino acids. They possess PAZ and CCCH domains. In sheep, TOPAZ1 mRNA is preferentially expressed in females during fetal life with a peak during prophase I of meiosis, and in males during adulthood. In the mouse, Topaz1 is a germ cell-specific gene. TOPAZ1 protein is highly conserved in vertebrates and specifically expressed in mouse and sheep gonads. It is localized in the cytoplasm of germ cells from the sheep fetal ovary and mouse adult testis. Conclusions We have identified a novel PAZ-domain protein that is abundantly expressed in the gonads during germ cell meiosis. The expression pattern of TOPAZ1, and its high degree of conservation, suggests that it may play an important role in germ cell development. Further characterization of TOPAZ1 may elucidate the mechanisms involved in gametogenesis, and particularly in the RNA silencing process in the germ line. PMID:22069478

  5. Human iPS Cell-Derived Germ Cells: Current Status and Clinical Potential.

    PubMed

    Ishii, Tetsuya

    2014-01-01

    Recently, fertile spermatozoa and oocytes were generated from mouse induced pluripotent (iPS) cells using a combined in vitro and in vivo induction system. With regard to germ cell induction from human iPS cells, progress has been made particularly in the male germline, demonstrating in vitro generation of haploid, round spermatids. Although iPS-derived germ cells are expected to be developed to yield a form of assisted reproductive technology (ART) that can address unmet reproductive needs, genetic and/or epigenetic instabilities abound in iPS cell generation and germ cell induction. In addition, there is still room to improve the induction protocol in the female germline. However, rapid advances in stem cell research are likely to make such obstacles surmountable, potentially translating induced germ cells into the clinical setting in the immediate future. This review examines the current status of the induction of germ cells from human iPS cells and discusses the clinical potential, as well as future directions. PMID:26237592

  6. Human iPS Cell-Derived Germ Cells: Current Status and Clinical Potential

    PubMed Central

    Ishii, Tetsuya

    2014-01-01

    Recently, fertile spermatozoa and oocytes were generated from mouse induced pluripotent (iPS) cells using a combined in vitro and in vivo induction system. With regard to germ cell induction from human iPS cells, progress has been made particularly in the male germline, demonstrating in vitro generation of haploid, round spermatids. Although iPS-derived germ cells are expected to be developed to yield a form of assisted reproductive technology (ART) that can address unmet reproductive needs, genetic and/or epigenetic instabilities abound in iPS cell generation and germ cell induction. In addition, there is still room to improve the induction protocol in the female germline. However, rapid advances in stem cell research are likely to make such obstacles surmountable, potentially translating induced germ cells into the clinical setting in the immediate future. This review examines the current status of the induction of germ cells from human iPS cells and discusses the clinical potential, as well as future directions. PMID:26237592

  7. Independent and coordinate trafficking of single Drosophila germ plasm mRNAs

    PubMed Central

    Little, Shawn C.; Sinsimer, Kristina S.; Lee, Jack J.; Wieschaus, Eric F.; Gavis, Elizabeth R.

    2015-01-01

    mRNA localization is a conserved mechanism for spatial control of protein synthesis, with key roles in generating cellular and developmental asymmetry. While different transcripts may be targeted to the same subcellular domain, the extent to which their localization is coordinated is unclear. Using quantitative single molecule imaging, we analyzed the assembly of Drosophila germ plasm mRNA granules inherited by nascent germ cells. We find that the germ cell-destined transcripts nanos, cyclin B, and polar granule component travel within the oocyte as ribonucleoprotein particles containing single mRNA molecules but co-assemble into multi-copy heterogeneous granules selectively at the posterior of the oocyte. The stoichiometry and dynamics of assembly indicate a defined stepwise sequence. Our data suggest that co-packaging of these transcripts ensures their effective segregation to germ cells. In contrast, compartmentalization of the germline determinant oskar mRNA into different granules limits its entry into germ cells. This exclusion is required for proper germline development. PMID:25848747

  8. Cisplatin resistance in germ cell tumours: models and mechanisms.

    PubMed

    Jacobsen, C; Honecker, F

    2015-01-01

    Recent years have led to a better understanding of the mechanisms underlying cisplatin response and resistance in germ cell tumours (GCT), and several promising targets have been identified. Two main mechanisms of the responsiveness to DNA damaging agents have been postulated. Firstly, GCT readily activate a DNA damage response, but show deficits in several damage repair pathways. In particular, they have been found to have defects in interstrand crosslink repair and in homologous recombination (HR). Secondly, GCT, especially embryonal carcinoma (EC) cells, show a hypersensitive apoptotic response to DNA damage, which activates p53, and leads to up-regulation of the pro-apoptotic factors Noxa, Puma and Fas in non-resistant EC. These cells fail to activate p21 which induces a G1/S arrest, but accumulate in G2/M phase. In the absence of functional p53, family members like p73 and GTAp63 might be important in initiating this response. Mechanisms involved in cisplatin resistance are as follows: down-regulation of Oct4 (e.g. as a result of hypoxia, treatment with retinoic acid or exposure to cisplatin) and failure to induce Puma and Noxa; changes in the expression levels of micro-RNAs such as miR-17/-106b, miR-302a, or miR-371 to -373; elevated levels of MDM2 and cytoplasmic translocation of p21 by phosphorylation; and activation of the PDGFR?/PI3K/pAKT pathway. Several approaches to overcome resistance have been successfully examined in vitro and in vivo, including PARP inhibitors, especially in cells showing deficient HR-repair; stabilization of p53 using nutlin-3; inhibition of several components of the PI3K/pAKT pathway using small molecules; and DNA demethylation by 5-azacytidine or 5-aza-deoxy-cytidine, among others. Many of these substances deserve further exploration, alone or in combination with DNA damaging agents, and the most promising approaches should be taken forward to clinical testing. Targeted therapy based on mechanistic insights holds the promise to turn cisplatin-resistant GCT into a curable disease. PMID:25546083

  9. Primary thrombocythemia

    MedlinePLUS

    Primary thrombocythemia is a condition in which the bone marrow produces too many platelets. Platelets are a ... Primary thrombocythemia is caused by the overproduction of platelets. If untreated, this condition gets worse over time. ...

  10. Primordial germ cell biology at the beginning of the XXI century.

    PubMed

    De Felici, Massimo

    2009-01-01

    At the XIV Workshop on the Development and Function of the Reproductive Organs held at the Congress Centre of the University of Rome Tor Vergata, Monteporzio Catone, Rome, Italy, the introduction to the first session entitled Mammalian primordial germ cells dedicated to the memory of Anne McLaren, was the occasion for a concise review of the state of art of research on the biology of primordial germ cells (PGCs). This great, unforgettable scientist, who died in a car accident in July 2007, dedicated most of her studies to this field over the last 25 years. Topics briefly reviewed in this Meeting Report are: 1) how the germ line is determined; 2) what are the mechanisms underlying PGC migration; 3) to what extent PGC survival, proliferation and differentiation are cell autonomous or environmentally controlled processes and 4) how the potential for totipotency is retained in PGCs. PMID:19598110

  11. 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. PMID:26180800

  12. An ABC transporter controls export of a Drosophila germ cell attractant.

    PubMed

    Ricardo, Sara; Lehmann, Ruth

    2009-02-13

    Directed cell migration, which is critical for embryonic development, leukocyte trafficking, and cell metastasis, depends on chemoattraction. 3-hydroxy-3-methylglutaryl coenzyme A reductase regulates the production of an attractant for Drosophila germ cells that may itself be geranylated. Chemoattractants are commonly secreted through a classical, signal peptide-dependent pathway, but a geranyl-modified attractant would require an alternative pathway. In budding yeast, pheromones produced by a-cells are farnesylated and secreted in a signal peptide-independent manner, requiring the adenosine triphosphate-binding cassette (ABC) transporter Ste6p. Here we show that Drosophila germ cell migration uses a similar pathway, demonstrating that invertebrate germ cells, like yeast cells, are attracted to lipid-modified peptides. Components of this unconventional export pathway are highly conserved, suggesting that this pathway may control the production of similarly modified chemoattractants in organisms ranging from yeast to humans. PMID:19213920

  13. Retention of ingested latex particles in Peyer's patches of germ-free and conventional mice

    SciTech Connect

    Lefevre, M.E.; Joel, D.D.; Schidlovsky, G.

    1985-09-01

    Conventional and germ-free mice ingested a suspension of 2-..mu..m latex particles in drinking water for a 15-day period. Number and distribution of intestinal Peyer's patches did not differ significantly in the two types of mice. Cleared Peyer's patches were compared with regard to size and particle content. The location of particles within Peyer's patch follicles of germ-free mice was similar to that of conventional mice, but the latter had significantly larger follicles and greater accumulations of latex particles. Latex concentration varied with patch location. Proximal patches contained the majority of particles in germ-free mice, whereas particles were most abundant in distal patches of conventional mice. The results show that particle uptake into Peyer's patches takes place even in the complete absence of bacteria in the gut.

  14. Germ plasm anchoring is a dynamic state that requires persistent trafficking.

    PubMed

    Sinsimer, Kristina S; Lee, Jack J; Thiberge, Stephan Y; Gavis, Elizabeth R

    2013-12-12

    Localized cytoplasmic determinants packaged as ribonucleoprotein (RNP) particles direct embryonic patterning and cell fate specification in a wide range of organisms. Once established, the asymmetric distributions of such RNP particles must be maintained, often over considerable developmental time. A striking example is the Drosophila germ plasm, which contains RNP particles whose localization to the posterior of the egg during oogenesis results in their asymmetric inheritance and segregation of germline from somatic fates in the embryo. Although actin-based anchoring mechanisms have been implicated, high-resolution live imaging revealed persistent trafficking of germ plasm RNP particles at the posterior cortex of the Drosophila oocyte. This motility relies on cortical microtubules, is mediated by kinesin and dynein motors, and requires coordination between the microtubule and actin cytoskeletons. Finally, we show that RNP particle motility is required for long-term germ plasm retention. We propose that anchoring is a dynamic state that renders asymmetries robust to developmental time and environmental perturbations. PMID:24290763

  15. 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

  16. 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.

  17. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish.

    PubMed

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-03-01

    Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. PMID:26852942

  18. Is the Blood-Brain Barrier Relevant in Metastatic Germ Cell Tumor?

    SciTech Connect

    Azar, Jose M. Schneider, Bryan P.; Einhorn, Lawrence H.

    2007-09-01

    Purpose: Germ cell tumors are uniquely chemosensitive and curable, even with advanced metastatic disease. Central nervous system recurrence can terminate a complete remission in other chemosensitive tumors, such as small cell lung cancer, because of the blood-brain barrier (BBB). We propose to document that the BBB is also relevant in germ cell tumors despite their dramatic chemosensitivity. Methods and Materials: We present five cases illustrating the concept of the BBB in patients with metastatic testicular cancer treated with chemotherapy. Results: In our large series of patients with metastatic testicular cancer treated with chemotherapy, we identified 5 unique patients. These patients were rendered free of disease only to experience relapse in the brain alone. This included 1 patient who initially had good-risk metastatic disease by means of the International Germ Cell Collaborative Group staging system at the onset of chemotherapy. Conclusions: The BBB is relevant in patients with metastatic testicular cancer.

  19. Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

    SciTech Connect

    Yamano, Noriko; Kimura, Tohru; Watanabe-Kushima, Shoko; Shinohara, Takashi; Nakano, Toru; Department of Pathology, Medical School, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871

    2010-02-12

    Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were cultured on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.

  20. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish

    PubMed Central

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-01-01

    Summary Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. PMID:26852942

  1. Germ cell development in the postnatal testis: the key to prevent malignancy in cryptorchidism?

    PubMed Central

    Hutson, John M.; Li, Ruili; Southwell, Bridget R.; Petersen, Bodil L.; Thorup, Jorgen; Cortes, Dina

    2013-01-01

    To permit normal postnatal germ cell development, the mammalian testis undergoes a complex, multi-staged process of descent to the scrotum. Failure of any part of this process leads to congenital cryptorchidism, wherein the malpositioned testis finds itself at the wrong temperature after birth, which leads to secondary germ cell loss and later infertility and risk of cancer. Recent studies suggest that neonatal gonocytes transform into the putative spermatogenic stem cells between 3 and 9 months, and this initial postnatal step is deranged in cryptorchid testes. In addition, it is thought the abnormality high temperature may also impair apoptosis of remaining gonocytes, allowing some to persist to become the possible source of carcinoma in situ and malignancy after puberty. The biology of postnatal germ cell development is of intense interest, as it is likely to be the key to the optimal timing for orchidopexy. PMID:23316184

  2. Germ cell development in the postnatal testis: the key to prevent malignancy in cryptorchidism?

    PubMed

    Hutson, John M; Li, Ruili; Southwell, Bridget R; Petersen, Bodil L; Thorup, Jorgen; Cortes, Dina

    2012-01-01

    To permit normal postnatal germ cell development, the mammalian testis undergoes a complex, multi-staged process of descent to the scrotum. Failure of any part of this process leads to congenital cryptorchidism, wherein the malpositioned testis finds itself at the wrong temperature after birth, which leads to secondary germ cell loss and later infertility and risk of cancer. Recent studies suggest that neonatal gonocytes transform into the putative spermatogenic stem cells between 3 and 9 months, and this initial postnatal step is deranged in cryptorchid testes. In addition, it is thought the abnormality high temperature may also impair apoptosis of remaining gonocytes, allowing some to persist to become the possible source of carcinoma in situ and malignancy after puberty. The biology of postnatal germ cell development is of intense interest, as it is likely to be the key to the optimal timing for orchidopexy. PMID:23316184

  3. 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

  4. Interphase chromosome painting of paraffin embedded tissue in the differential diagnosis of possible male germ cell tumors

    SciTech Connect

    Blough, R.I.; Heerema, N.A.; Smolarek, T.A.

    1994-09-01

    Germ cell tumors (GCTs) are a leading cause of cancer in young men ages 15-34, and in many cases have metastasized prior to clinical presentation. In some instances, metastatic GCTs have manifested as distinct, non-GCT malignancies, including rhabdomyosarcoma, peripheral neuroepithelioma, and neuroblastoma. In cases where the primary tumor is unknown, or of poorly differentiated pathology, the presence of non-GCT elements may obscure the diagnosis and choice of treatment regimen. Traditional cytogenetic analysis to screen for chromosome 12p rearrangements, especially i(12), is frequently desirable in such cases, but is often overlooked until other avenues of diagnosis are exhausted, at which point no fresh tissue remains. We have developed a reliable technique for fluorescence in situ hybridization (FISH) whole chromosome painting on interphase nuclei released from formalin fixed, paraffin embedded tissues (PET), using painting probes for chromosome 12p and 12q produced by chromosomal microdissection. Using bicolor FISH with these probes, the relative nuclear distribution of 12p and 12q regions can be observed. We successfully applied this technique to four tumors with poorly defined pathology or unknown primary tumors and with a differential diagnosis of GCT. In each case, 12p and 12q could be distinguished, and 12p regions appeared to be rearranged and overrepresented relative to 12q regions. In 3 of 4 cases, a putative i(12p) was identified. These results support a diagnosis of GCT or GCT origin in these three cases.

  5. Sufficient Numbers of Early Germ Cells Are Essential for Female Sex Development in Zebrafish

    PubMed Central

    Dai, Xiangyan; Jin, Xia; Chen, Xiaowen; He, Jiangyan; Yin, Zhan

    2015-01-01

    The sex determination for zebrafish is controlled by a combination of genetic and environmental factors. The determination of sex in zebrafish has been suggested to rely on a mechanism that is affected by germ cell-derived signals. To begin our current study, a simplified and efficient germ cell-specific promoter of the dead end (dnd) gene was identified. Utilizing the metrodinazole (MTZ)/ bacterial nitroreductase (NTR) system for inducible germ cell ablation, several stable Tg (dnd:NTR-EGFP-3'UTR) and Tg (dnd:NTR-EGFP+3'UTR) zebrafish lines were then generated with the identified promoter. A thorough comparison of the expression patterns and tissue distributions of endogenous dnd and ntr-egfp transcripts in vivo revealed that the identified 2032-bp zebrafish dnd promoter can recapitulate dnd expression faithfully in stable transgenic zebrafish. The correlation between the levels of the germ cell-derived signals and requirement for maintaining the female fate has been also explored with different durations of the MTZ treatments. Our results revealed the decreasing ratios of female presented in the treated transgenic group are fairly associated with the reducing levels of the early germ cell-derived signals. After the juvenile transgenic fish treated with 5 mM MTZ for 20 days, all MTZ-treated transgenic fish exclusively developed into males with subfertilities. Taken together, our results identified here a simplified and efficient dnd promoter, and provide clear evidence indicating that it was not the presence but the sufficiency of signals derived from germ cells that is essential for female sex development in zebrafish. Our model also provides a unique system for sex control in zebrafish studies. PMID:25679390

  6. Sufficient numbers of early germ cells are essential for female sex development in zebrafish.

    PubMed

    Dai, Xiangyan; Jin, Xia; Chen, Xiaowen; He, Jiangyan; Yin, Zhan

    2015-01-01

    The sex determination for zebrafish is controlled by a combination of genetic and environmental factors. The determination of sex in zebrafish has been suggested to rely on a mechanism that is affected by germ cell-derived signals. To begin our current study, a simplified and efficient germ cell-specific promoter of the dead end (dnd) gene was identified. Utilizing the metrodinazole (MTZ)/ bacterial nitroreductase (NTR) system for inducible germ cell ablation, several stable Tg (dnd:NTR-EGFP(-3'UTR)) and Tg (dnd:NTR-EGFP(+3'UTR)) zebrafish lines were then generated with the identified promoter. A thorough comparison of the expression patterns and tissue distributions of endogenous dnd and ntr-egfp transcripts in vivo revealed that the identified 2032-bp zebrafish dnd promoter can recapitulate dnd expression faithfully in stable transgenic zebrafish. The correlation between the levels of the germ cell-derived signals and requirement for maintaining the female fate has been also explored with different durations of the MTZ treatments. Our results revealed the decreasing ratios of female presented in the treated transgenic group are fairly associated with the reducing levels of the early germ cell-derived signals. After the juvenile transgenic fish treated with 5 mM MTZ for 20 days, all MTZ-treated transgenic fish exclusively developed into males with subfertilities. Taken together, our results identified here a simplified and efficient dnd promoter, and provide clear evidence indicating that it was not the presence but the sufficiency of signals derived from germ cells that is essential for female sex development in zebrafish. Our model also provides a unique system for sex control in zebrafish studies. PMID:25679390

  7. Sertoli-germ cell junctions in the testis: a review of recent data.

    PubMed

    Kopera, Ilona A; Bilinska, Barbara; Cheng, C Yan; Mruk, Dolores D

    2010-05-27

    Spermatogenesis is a process that involves an array of cellular and biochemical events, collectively culminating in the formation of haploid spermatids from diploid precursor cells known as spermatogonia. As germ cells differentiate from spermatogonia into elongated spermatids, they also progressively migrate across the entire length of the seminiferous epithelium until they reach the luminal edge in anticipation of spermiation at late stage VIII of spermatogenesis. At the same time, these germ cells must maintain stable attachment with Sertoli cells via testis-unique intermediate filament- (i.e. desmosome-like junctions) and actin- (i.e. ectoplasmic specializations, ESs) based cell junctions to prevent sloughing of immature germ cells from the seminiferous epithelium, which may result in infertility. In essence, both desmosome-like junctions and basal ESs are known to coexist between Sertoli cells at the level of the blood-testis barrier where they cofunction with the well-studied tight junction in maintaining the immunological barrier. However, the type of anchoring device that is present between Sertoli and germ cells depends on the developmental stage of the germ cell, i.e. desmosome-like junctions are present between Sertoli and germ cells up to, but not including, step 8 spermatids after which this junction type is replaced by the apical ES. While little is known about the biology of the desmosome-like junction in the testis, we have a relatively good understanding of the molecular architecture and the regulation of the ES. Here, we discuss recent findings relating to these two junction types in the testis, highlighting prospective areas that should be investigated in future studies. PMID:20403872

  8. Spermatogenesis and germ cell transgene expression in xenografted bovine testicular tissue.

    PubMed

    Oatley, Jon M; de Avila, David M; Reeves, Jerry J; McLean, Derek J

    2004-08-01

    The present study was conducted to evaluate the development of spermatogenesis and utility of using electroporation to stably transfect germ cells with the beta-galactosidase gene in neonatal bovine testicular tissue ectopically xenografted onto the backs of recipient nude mice. Bull testicular tissue from 4-wk donor calves, which contains a germ cell population consisting solely of gonocytes or undifferentiated spermatogonia, was grafted onto the backs of castrated adult recipient nude mice. Testicular grafts significantly increased in weight throughout the grafting period and the timing of germ cell differentiation in grafted tissue was consistent with postnatal testis development in vivo relative to the bull. Seminiferous tubule diameter also significantly increased with advancing time after grafting. At 1 wk after grafting, gonocytes in the seminiferous cords completed migration to the basement membrane and differentiated germ cell types could be observed 24 wk after grafting. The presence of elongating spermatids at 24 wk confirmed that germ cell differentiation occurred in the bovine tissue. Leydig cells in the grafted bovine tissue were also capable of producing testosterone in the castrated recipient mice from 4 wk to 24 wk after grafting at concentrations that were similar to levels in intact, nongrafted control mice. The testicular tissue that had been electroporated with a beta-galactosidase expression vector showed tubule-specific transgene expression 24 wk after grafting. Histological analysis showed that transgene expression was present in both Sertoli and differentiated germ cells but not in interstitial cells. The system reported here has the potential to be used for generation of transgenic bovine spermatozoa. PMID:15070832

  9. Developmental expression of the translocator protein 18 kDa (TSPO) in testicular germ cells.

    PubMed

    Manku, G; Wang, Y; Thuillier, R; Rhodes, C; Culty, M

    2012-05-01

    Translocator protein (TSPO) is a high affinity 18 kDa drug- and cholesterol-binding protein strongly expressed in steroidogenic tissues where it mediates cholesterol transport into mitochondria and steroid formation. Testosterone formation by Leydig cells in the testis is critical for the regulation of spermatogenesis and male fertility. Male germ cell development comprises two main phases, the pre-spermatogenesis phase occurring from fetal life to infancy and leading to spermatogonial stem cell (SSC) formation, and spermatogenesis, which consists of repetitive cycles of germ cell mitosis, meiosis and differentiation, starting with SSC differentiation and ending with spermiogenesis and spermatozoa formation. Little is known about the molecular mechanisms controlling the progression from one germ cell phenotype to the next. Here, we report that testicular germ cells express TSPO from neonatal to adult phases, although at lower levels than Leydig cells. TSPO mRNA and protein were found at specific steps of germ cell development. In fetal and neonatal gonocytes, the precursors of SSCs, TSPO appears to be mainly nuclear. In the prepubertal testis, TSPO is present in pachytene spermatocytes and dividing spermatogonia. In adult testes, it is found in a stage-dependent manner in pachytene spermatocyte and round spermatid nuclei, and in mitotic spermatogonia. In search of TSPO function, the TSPO drug ligand PK 11195 was added to isolated gonocytes with or without the proliferative factors PDGF and 17?-estradiol, and was found to have no effect on gonocyte proliferation. However, TSPO strong expression in dividing spermatogonia suggests that it might play a role in spermatogonial mitosis. Taken together, these results suggest that TSPO plays a role in specific phases of germ cell development. PMID:22348614

  10. Proteasome regulation of the chromodomain protein MRG-1 controls the balance between proliferative fate and differentiation in the C. elegans germ line.

    PubMed

    Gupta, Pratyush; Leahul, Lindsay; Wang, Xin; Wang, Chris; Bakos, Brendan; Jasper, Katie; Hansen, Dave

    2015-01-15

    The level of stem cell proliferation must be tightly controlled for proper development and tissue homeostasis. Multiple levels of gene regulation are often employed to regulate stem cell proliferation to ensure that the amount of proliferation is aligned with the needs of the tissue. Here we focus on proteasome-mediated protein degradation as a means of regulating the activities of proteins involved in controlling the stem cell proliferative fate in the C. elegans germ line. We identify five potential E3 ubiquitin ligases, including the RFP-1 RING finger protein, as being involved in regulating proliferative fate. RFP-1 binds to MRG-1, a homologue of the mammalian chromodomain-containing protein MRG15 (MORF4L1), which has been implicated in promoting the proliferation of neural precursor cells. We find that C. elegans with reduced proteasome activity, or that lack RFP-1 expression, have increased levels of MRG-1 and a shift towards increased proliferation in sensitized genetic backgrounds. Likewise, reduction of MRG-1 partially suppresses stem cell overproliferation. MRG-1 levels are controlled independently of the spatially regulated GLP-1/Notch signalling pathway, which is the primary signal controlling the extent of stem cell proliferation in the C. elegans germ line. We propose a model in which MRG-1 levels are controlled, at least in part, by the proteasome, and that the levels of MRG-1 set a threshold upon which other spatially regulated factors act in order to control the balance between the proliferative fate and differentiation in the C. elegans germ line. PMID:25564623

  11. Genome Analysis of Elysia chlorotica Egg DNA Provides No Evidence for Horizontal Gene Transfer into the Germ Line of This Kleptoplastic Mollusc

    PubMed Central

    Bhattacharya, Debashish; Pelletreau, Karen N.; Price, Dana C.; Sarver, Kara E.; Rumpho, Mary E.

    2013-01-01

    The sea slug Elysia chlorotica offers a unique opportunity to study the evolution of a novel function (photosynthesis) in a complex multicellular host. Elysia chlorotica harvests plastids (absent of nuclei) from its heterokont algal prey, Vaucheria litorea. The “stolen” plastids are maintained for several months in cells of the digestive tract and are essential for animal development. The basis of long-term maintenance of photosynthesis in this sea slug was thought to be explained by extensive horizontal gene transfer (HGT) from the nucleus of the alga to the animal nucleus, followed by expression of algal genes in the gut to provide essential plastid-destined proteins. Early studies of target genes and proteins supported the HGT hypothesis, but more recent genome-wide data provide conflicting results. Here, we generated significant genome data from the E. chlorotica germ line (egg DNA) and from V. litorea to test the HGT hypothesis. Our comprehensive analyses fail to provide evidence for alga-derived HGT into the germ line of the sea slug. Polymerase chain reaction analyses of genomic DNA and cDNA from different individual E. chlorotica suggest, however, that algal nuclear genes (or gene fragments) are present in the adult slug. We suggest that these nucleic acids may derive from and/or reside in extrachromosomal DNAs that are made available to the animal through contact with the alga. These data resolve a long-standing issue and suggest that HGT is not the primary reason underlying long-term maintenance of photosynthesis in E. chlorotica. Therefore, sea slug photosynthesis is sustained in as yet unexplained ways that do not appear to endanger the animal germ line through the introduction of dozens of foreign genes. PMID:23645554

  12. Genome analysis of Elysia chlorotica Egg DNA provides no evidence for horizontal gene transfer into the germ line of this Kleptoplastic Mollusc.

    PubMed

    Bhattacharya, Debashish; Pelletreau, Karen N; Price, Dana C; Sarver, Kara E; Rumpho, Mary E

    2013-08-01

    The sea slug Elysia chlorotica offers a unique opportunity to study the evolution of a novel function (photosynthesis) in a complex multicellular host. Elysia chlorotica harvests plastids (absent of nuclei) from its heterokont algal prey, Vaucheria litorea. The "stolen" plastids are maintained for several months in cells of the digestive tract and are essential for animal development. The basis of long-term maintenance of photosynthesis in this sea slug was thought to be explained by extensive horizontal gene transfer (HGT) from the nucleus of the alga to the animal nucleus, followed by expression of algal genes in the gut to provide essential plastid-destined proteins. Early studies of target genes and proteins supported the HGT hypothesis, but more recent genome-wide data provide conflicting results. Here, we generated significant genome data from the E. chlorotica germ line (egg DNA) and from V. litorea to test the HGT hypothesis. Our comprehensive analyses fail to provide evidence for alga-derived HGT into the germ line of the sea slug. Polymerase chain reaction analyses of genomic DNA and cDNA from different individual E. chlorotica suggest, however, that algal nuclear genes (or gene fragments) are present in the adult slug. We suggest that these nucleic acids may derive from and/or reside in extrachromosomal DNAs that are made available to the animal through contact with the alga. These data resolve a long-standing issue and suggest that HGT is not the primary reason underlying long-term maintenance of photosynthesis in E. chlorotica. Therefore, sea slug photosynthesis is sustained in as yet unexplained ways that do not appear to endanger the animal germ line through the introduction of dozens of foreign genes. PMID:23645554

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

    SciTech Connect

    Kheradmand, Arash; Dezfoulian, Omid; Alirezaei, Masoud; Rasoulian, Bahram

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact, 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.

  14. Enhanced Toxicity of Nervous System Drugs for Germ-Free Mice

    PubMed Central

    Lamanna, Carl; Ward, Thomas G.

    1970-01-01

    Germ-free mice were found to be more sensitive than conventional mice to poisoning by hemicholinium-3, hexamethonium chloride, strychnine sulfate, sodium pentobarbital, sodium barbital, and histamine diphosphate. On the other hand, conventional mice were more sensitive to atropine. No difference between germ-free and conventional mice was found in sensitivity to d-tubocurarine, metrazol, and picrotoxin. These findings raise a question as to the influence of exposure to microorganisms in the development of sensitivity to drugs acting on the nervous system. PMID:16557703

  15. GermlncRNA: a unique catalogue of long non-coding RNAs and associated regulations in male germ cell development.

    PubMed

    Luk, Alfred Chun-Shui; Gao, Huayan; Xiao, Sizhe; Liao, Jinyue; Wang, Daxi; Tu, Jiajie; Rennert, Owen M; Chan, Wai-Yee; Lee, Tin-Lap

    2015-01-01

    Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/ PMID:25982314

  16. 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

  17. 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

  18. Xenopus Xpat protein is a major component of germ plasm and may function in its organisation and positioning.

    PubMed

    Machado, Rachel J; Moore, Wendy; Hames, Richard; Houliston, Evelyn; Chang, Patrick; King, Mary Lou; Woodland, Hugh R

    2005-11-15

    In many animals, including Drosophila, C. elegans, zebrafish and Xenopus, the germ line is specified by maternal determinants localised in a distinct cytoplasmic structure called the germ plasm. This is consists of dense granules, mitochondria, and specific localised RNAs. We have characterised the expression and properties of the protein encoded by Xpat, an RNA localised to the germ plasm of Xenopus. Immunofluorescence and immunoblotting showed that this novel protein is itself a major constituent of germ plasm throughout oogenesis and early development, although it is also present in other regions of oocytes and embryos, including their nuclei. We found that an Xpat-GFP fusion protein can localise correctly in cultured oocytes, in early oocytes to the 'mitochondrial cloud', from which germ plasm originates, and in later oocytes to the vegetal cortex. The localisation process was microtubule-dependent, while cortical anchoring required microfilaments. Xpat-GFP expressed in late stage oocytes assembled into circular fields of multi-particulate structures resembling endogenous fields of germ plasm islands. Furthermore these structures could be induced to form at ectopic sites by manipulation of culture conditions. Ectopic Xpat-GFP islands were able to recruit mitochondria, a major germ plasm component. These data suggest that Xpat protein has an important role in Xenopus germ plasm formation, positioning and maintenance. PMID:16216237

  19. 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...

  20. Layer 6 Corticothalamic Neurons Activate a Cortical Output Layer, Layer 5a

    PubMed Central

    Kim, Juhyun; Matney, Chanel J.; Blankenship, Aaron; Hestrin, Shaul

    2014-01-01

    Layer 6 corticothalamic neurons are thought to modulate incoming sensory information via their intracortical axons targeting the major thalamorecipient layer of the neocortex, layer 4, and via their long-range feedback projections to primary sensory thalamic nuclei. However, anatomical reconstructions of individual layer 6 corticothalamic (L6 CT) neurons include examples with axonal processes ramifying within layer 5, and the relative input of the overall population of L6 CT neurons to layers 4 and 5 is not well understood. We compared the synaptic impact of L6 CT cells on neurons in layers 4 and 5. We found that the axons of L6 CT neurons densely ramified within layer 5a in both visual and somatosensory cortices of the mouse. Optogenetic activation of corticothalamic neurons generated large EPSPs in pyramidal neurons in layer 5a. In contrast, excitatory neurons in layer 4 exhibited weak excitation or disynaptic inhibition. Fast-spiking parvalbumin-positive cells in both layer 5a and layer 4 were also strongly activated by L6 CT neurons. The overall effect of L6 CT activation was to suppress layer 4 while eliciting action potentials in layer 5a pyramidal neurons. Together, our data indicate that L6 CT neurons strongly activate an output layer of the cortex. PMID:25031405

  1. Sex determination. foxl3 is a germ cell-intrinsic factor involved in sperm-egg fate decision in medaka.

    PubMed

    Nishimura, Toshiya; Sato, Tetsuya; Yamamoto, Yasuhiro; Watakabe, Ikuko; Ohkawa, Yasuyuki; Suyama, Mikita; Kobayashi, Satoru; Tanaka, Minoru

    2015-07-17

    Sex determination is an essential step in the commitment of a germ cell to a sperm or egg. However, the intrinsic factors that determine the sexual fate of vertebrate germ cells are unknown. Here, we show that foxl3, which is expressed in germ cells but not somatic cells in the gonad, is involved in sperm-egg fate decision in medaka fish. Adult XX medaka with disrupted foxl3 developed functional sperm in the expanded germinal epithelium of a histologically functional ovary. In chimeric medaka, mutant germ cells initiated spermatogenesis in female wild-type gonad. These results indicate that a germ cell-intrinsic cue for the sperm-egg fate decision is present in medaka and that spermatogenesis can proceed in a female gonadal environment. PMID:26067255

  2. Mixed Germ Cell Tumor of Testis with Isolated Scapular Metastasis: A Case Report and Review of the Literature

    PubMed Central

    Samanta, Dipti Rani; Bose, Chaitali; Krishnappa, Roopesh; Mishra, Saumyaranjan; Mohanty, Sulagna; Upadhyay, Ashish; Senapati, Surendra Nath

    2015-01-01

    Bone metastasis is a rare entity in germ cell tumor of testis and is a poor prognostic site. It is usually associated with synchronous metastasis at other sites. Till now very few cases of isolated bone metastasis of germ cell tumor of testis have been reported but none have reported scapular metastasis. We are reporting a case of nonseminomatous germ cell tumor of right testis that was operated eight months ago and now presented with isolated scapular metastasis. Histopathology of the scapular tissue revealed rhabdomyosarcoma or poorly differentiated synovial sarcoma. Immunohistochemistry with serum markers concluded it to be metastatic germ cell tumor. To the best of our knowledge this is the first reported case of scapular metastasis of testicular germ cell tumor. This case is being reported here due to dilemmatic way of presentation and also to emphasize that histopathology may sometimes misguide and immunohistochemistry is necessary in such cases. PMID:26351612

  3. [Geldanamycin administration reduces the number of HSP86-positive germ cells in the mouse embryo: preliminary results].

    TOXLINE Toxicology Bibliographic Information

    Vanmuylder N; Larbi H; Choa-Duterre M; Salvia P; Rooze M; Louryan S

    2009-01-01

    5 mg of Geldanamycin, an inhibitor of stress protein HSP86 which express on mammalian germ cells, were administered to E8 pregnant mice. E17 embryos were removed, and a quantitative analysis of HSP90-immunoreactive cells in the gonad was performed, in comparison to control embryos. First, we observed that the number of germ cells is lower in male than in female embryos, as well in control and experimental embryos. External features of experimental and control embryos did not display any difference. Embryos exposed to geldanamycin exhibit a significant decrease of immunoreactive germ cells. In two embryos, we observed a group of ectopic immunoreactive cells in the pelvic area. We conclude that geldanamycin inhibits germ cells migration, and suggest that this inhibition can lead to ectopic germ cell populations, similar to teratomas.

  4. Histological analysis of spermatogenesis and the germ cell development strategy within the testis of the male Western Cottonmouth Snake, Agkistrodon piscivorus leucostoma.

    PubMed

    Gribbins, Kevin M; Rheubert, Justin L; Collier, Matthew H; Siegel, Dustin S; Sever, David M

    2008-11-20

    Cottonmouth (Agkistrodon piscivorus leucostoma) testes were examined histologically to determine the germ cell development strategy employed during spermatogenesis. Testicular tissues from Cottonmouths were collected monthly from swamps around Hammond, Louisiana. Pieces of testis were fixed in Trump's fixative, dehydrated in ethanol, embedded in Spurr's plastic, sectioned with an ultramicrotome, and stained with toluidine blue and basic fuchsin. Spermatogenesis within Cottonmouths occurs in two independent events within a single calendar year. The testes are active during the months of March-June and August-October with spermiation most heavily observed during April-May and October. To our knowledge, this is the first study that describes bimodal spermatogenesis occurring in the same year within the subfamily Crotalinae. During spermatogenesis, no consistent spatial relationships are observed between germ cell generations. Typically, either certain cell types were missing (spermatocytes) or the layering of 3-5 spermatids and/or spermatocytes within the same cross-section of seminiferous tubule prevented consistent spatial stages from occurring. This temporal pattern of sperm development is different from the spatial development found within birds and mammals, being more reminiscent of that seen in amphibians, and has now been documented within every major clade of reptile (Chelonia, Serpentes, Sauria, Crocodylia). This primitive-like sperm development, within a testis structurally similar to mammals and birds, may represent an intermediate testicular model within the basally positioned (phylogenetically) reptiles that may be evolutionarily significant. PMID:18926676

  5. LIN28 Is Selectively Expressed by Primordial and Pre-Meiotic Germ Cells in the Human Fetal Ovary

    PubMed Central

    Kinnell, Hazel L.; He, Jing; Anderson, Richard A.

    2012-01-01

    Germ cell development requires timely transition from primordial germ cell (PGC) self-renewal to meiotic differentiation. This is associated with widespread changes in gene expression, including downregulation of stem cell–associated genes, such as OCT4 and KIT, and upregulation of markers of germ cell differentiation and meiosis, such as VASA, STRA8, and SYCP3. The stem cell–expressed RNA-binding protein Lin28 has recently been demonstrated to be essential for PGC specification in mice, and LIN28 is expressed in human germ cell tumors with phenotypic similarities to human fetal germ cells. We have therefore examined the expression of LIN28 during normal germ cell development in the human fetal ovary, from the PGC stage, through meiosis to the initiation of follicle formation. LIN28 transcript levels were highest when the gonad contained only PGCs, and decreased significantly with increasing gestation, coincident with the onset of germ cell differentiation. Immunohistochemistry revealed LIN28 protein expression to be germ cell–specific at all stages examined. All PGCs expressed LIN28, but at later gestations expression was restricted to a subpopulation of germ cells, which we demonstrate to be primordial and premeiotic germ cells based on immunofluorescent colocalization of LIN28 and OCT4, and absence of overlap with the meiosis marker SYCP3. We also demonstrate the expression of the LIN28 target precursor pri-microRNA transcripts pri-LET7a/f/d and pri-LET-7g in the human fetal ovary, and that expression of these is highest at the PGC stage, mirroring that of LIN28. The spatial and temporal restriction of LIN28 expression and coincident peaks of expression of LIN28 and target pri-microRNAs suggest important roles for this protein in the maintenance of the germline stem cell state and the regulation of microRNA activity in the developing human ovary. PMID:22296229

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

    SciTech Connect

    Pellegrina, Chiara Dalla; Perbellini, Omar; Scupoli, Maria Teresa; Tomelleri, Carlo; Zanetti, Chiara; Zoccatelli, Gianni; Fusi, Marina; Peruffo, Angelo; Rizzi, Corrado; Chignola, Roberto

    2009-06-01

    Wheat germ agglutinin (WGA) is a plant protein that binds specifically to sugars expressed, among many others, by human gastrointestinal epithelial and immune cells. WGA is a toxic compound and an anti-nutritional factor, but recent works have shown that it may have potential as an anti-tumor drug and as a carrier for oral drugs. To quantitate the toxicity threshold for WGA on normal epithelial cells we previously investigated the effects of the lectin on differentiated Caco2 cells, and showed that in the micromolar range of concentrations WGA could alter the integrity of the epithelium layer and increase its permeability to both mannitol and dextran. WGA was shown to be uptaken by Caco2 cells and only {approx} 0.1% molecules were observed to cross the epithelium layer by transcytosis. Here we show that at nanomolar concentrations WGA is unexpectedly bioactive on immune cells. The supernatants of WGA-stimulated peripheral blood mononuclear cells (PBMC) can alter the integrity of the epithelium layer when administered to the basolateral side of differentiated Caco2 cells and the effects can be partially inhibited by monoclonal antibodies against IL1, IL6 and IL8. At nanomolar concentrations WGA stimulates the synthesis of pro-inflammatory cytokines and thus the biological activity of WGA should be reconsidered by taking into account the effects of WGA on the immune system at the gastrointestinal interface. These results shed new light onto the molecular mechanisms underlying the onset of gastrointestinal disorders observed in vivo upon dietary intake of wheat-based foods.

  7. GLD-4-mediated translational activation regulates the size of the proliferative germ cell pool in the adult C. elegans germ line.

    PubMed

    Millonigg, Sophia; Minasaki, Ryuji; Nousch, Marco; Eckmann, Christian R

    2014-09-01

    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

  8. 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

  9. 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...

  10. WHEAT GERM OIL AND A LOW WASTE LIQUID LARVAL DIET FOR REARING ORIENTAL FRUIT FLIES, BACTROCERA DORSALIS(HENDEL) (DIPTERA: TEPHRITIDAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat germ oil was added into a low waste larval liquid diet for rearing Bactrocera dorsalis (Hendel) to optimize the fruit fly performance. Various concentrations of 0.04, 0.07, 0.15, 0.30, and 0.66 % of wheat germ oil were evaluated. Results showed that the addition of wheat germ oil did not affec...

  11. Bilateral germ-cell tumours: 22-year experience at the Institut Gustave Roussy.

    PubMed

    Theodore, Ch; Terrier-Lacombe, M J; Laplanche, A; Benoit, G; Fizazi, K; Stamerra, O; Wibault, P

    2004-01-12

    The aim of this study was to describe the incidence, clinical and histological characteristics, treatment and long-term follow-up of bilateral germ-cell tumours (BGCT) of the testis in order to determine in what respects they differ significantly from unilateral germ-cell tumours. In all, 31 patients with BGCT had metachronous tumours and 14 had synchronous tumours. Among the metachronous tumours, 61% occurred more than 5 years after the first tumour. The overall incidence of BGCT in patients with testicular germ-cell tumours (TGCT) was 1.9%. The incidence was 3.2% in patients presenting with a seminoma and 1.4 % in patients presenting with a nonseminomatous germ-cell tumour (NSGCT). Patients under 30 years of age at the time of the initial diagnosis had a higher incidence of bilateral tumours compared with older men. The outcome of BGCT was excellent. A high association was found between BGCT, sterility and suspected genetic risk factors for TGCT. These results argue against a systematic contralateral biopsy at diagnosis of first TGCT in all patients, but emphasise the importance of patient education and of the need to better identify patients at risk for a second TGCT. Therapeutic indications for synchronous BGCT, including conservative treatment, need to be better defined. PMID:14710206

  12. Differentiation of early germ cells from human skin-derived stem cells without exogenous gene integration

    PubMed Central

    Ge, Wei; Ma, Hua-Gang; Cheng, Shun-Feng; Sun, Yuan-Chao; Sun, Li-Lan; Sun, Xiao-Feng; Li, Lan; Dyce, Paul; Li, Julang; Shi, Qing-Hua; Shen, Wei

    2015-01-01

    Infertility has long been a difficult issue for many couples. The successful differentiation of germ cells and live progeny from pluripotent stem cells brings new hope to the couples suffering with infertility. Here we successfully isolated human fetus skin-derived stem cells (hfSDSCs) from fetus skin tissue and demonstrated that hfSDSCs can be differentiated into early human germ cell-like cells (hGCLCs). These cells express human germ cell markers DAZL and VASA. Moreover, these pluripotent stem cell-derived hGCLCs are free of exogenous gene integration. When hfSDSCs were differentiated in porcine follicle fluid (PFF) conditioned media, which has been shown to promote the differentiation of mouse and porcine SDSCs into oocyte-like cells (OLCs), we observed some vesicular structures formed from hfSDSCs. Moreover, when hfSDSCs were cultured with specific conditioned media, we observed punctate and elongated SCP3 staining foci, indicating the initiation of meiosis. Ploidy analysis and fluorescent in situ hybridization (FISH) analysis indicated that a small percentage of putative 1N populations formed from hfSDSCs when compared with positive controls. In conclusion, our data here, for the first time, demonstrated that hfSDSCs possess the differentiation potential into germ lines, and they may differentiate both male and female hGCLCs in vitro under appropriate conditions. PMID:26347377

  13. Human Hemochromatosis Protein (HFE) Immunoperoxidase Stain Highlights Choriocarcinoma within Mixed Germ Cell Tumors

    PubMed Central

    Talmon, Geoffrey A.; Koepsell, Scott A.

    2016-01-01

    Identification of choriocarcinoma within a germ cell tumor can have major implications for the subsequent staging and treatment of testicular neoplasms. Immunoperoxidase staining greatly enhances the speed and sensitivity of identifying occult, though clinically significant, tumor components. In mixed germ cell tumors, staining for beta-human chorionic gonadotropin (β-hCG) has been historically used to assess for the presence and burden of choriocarcinoma. However, current β-hCG stains produce variable, intense staining of trophoblastic elements and surrounding tissues, clouding the assessment of true-positive staining. Human hemochromatosis protein (HFE) is a membrane bound mediator of iron transport expressed at high levels within placenta. Additionally, previous reports have demonstrated that choriocarcinoma cell lines express HFE, although in vivo expression had not been examined. To address whether HFE can stain trophoblastic elements, HFE immunohistochemistry was conducted in choriocarcinoma (n = 4), mixed germ cell tumors (n = 11), seminoma (n = 4), and placenta (n = 11). HFE consistently demonstrated cytoplasmic and membranous staining, highlighting both syncytiotrophoblasts and cytotrophoblasts within choriocarcinoma and placenta. Staining of intratumoral white blood cells was observed within seminomas and mixed germ cell tumors, corroborating prior reports stating that HFE highlights monocytes and macrophages. Taken together, HFE may serve as an alternative target from β-hCG for immunoperoxidase studies when highlighting choriocarcinoma.

  14. 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

  15. Neurl4 contributes to germ cell formation and integrity in Drosophila

    PubMed Central

    Jones, Jennifer; Macdonald, Paul M.

    2015-01-01

    ABSTRACT Primordial germ