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Sample records for primary germ layers

  1. Neural crest: The fourth germ layer

    PubMed Central

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

    2015-01-01

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

  2. Glycolipids of human primary testicular germ cell tumours.

    PubMed Central

    Olie, R. A.; Fenderson, B.; Daley, K.; Oosterhuis, J. W.; Murphy, J.; Looijenga, L. H.

    1996-01-01

    The glycolipid content of human non-seminomatous germ cell tumour cell lines correlates with their differentiation lineage. To analyse whether this reflects the situation in primary tumours, we studied five embryonal carcinomas, five yolk sac tumours and nine (mixed) non-seminomas, using thin-layer chromatography and carbohydrate immunostaining. We also analysed the glycolipid content of 19 seminomas to reveal their relationship with non-seminomas. Lactosylceramide (CDH) was detected in all embryonal carcinomas, but in fewer than half of the seminomas. Seminomas and embryonal carcinomas contained globoseries glycolipids, including globotriosylceramide (Gb3), globoside (Gb4), galactosy globoside (Gb5) and sialy1 galactosyl globoside (GL7). The lacto-series glycolipid Le(x) was found in all embryonal carcinomas, but only in one seminoma. Gangliosides GD3 and GT3 were detected in many seminomas, but rarely in embryonal carcinomas. Yolk sac tumours displayed a heterogeneous glycolipid profile. Compared with seminomas and pure embryonal carcinomas, differentiated non-seminomas had reduced levels of globo-series glycolipids, especially Gb3 and Gb5, whereas CDH, Le(x), GD3 and GT3 were found in the majority of cases. Thus, the glycolipid content of non-seminoma cell lines reflects the situation in primary tumours. Globo-series glycolipids are similarly expressed in seminomas and embryonal carcinomas. The expression of Gb3 and Gb5 is reduced in non-seminomas upon differentiation. Le(x) expression in non-seminomas, including embryonal carcinomas, allows discrimination from seminomas. Expression of gangliosides in seminomas might indicate their maturation from ganglioside-negative precursor cells. Reprogramming of these precursors would result in the formation of Le(x)-expressing embryonal carcinomas. Images Figure 1 Figure 2 PMID:8679447

  3. 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

  4. 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

  5. Germ layer specification and axial patterning in the embryonic development of the freshwater planarian Schmidtea polychroa.

    PubMed

    Martín-Durán, José María; Amaya, Enrique; Romero, Rafael

    2010-04-01

    Although patterning during regeneration in adult planarians has been studied extensively, very little is known about how the initial planarian body plan arises during embryogenesis. Herein, we analyze the process of embryo patterning in the species Schmidtea polychroa by comparing the expression of genes involved in the establishment of the metazoan body plan. Planarians present a derived ectolecithic spiralian development characterized by dispersed cleavage within a yolk syncytium and an early transient embryo capable of feeding on the maternally supplied yolk cells. During this stage of development, we only found evidence of canonical Wnt pathway, mostly associated with the development of its transient pharynx. At these stages, genes involved in gastrulation (snail) and germ layer determination (foxA and twist) are specifically expressed in migrating blastomeres and those giving rise to the temporary gut and pharyngeal muscle. After yolk ingestion, the embryo expresses core components of the canonical Wnt pathway and the BMP pathway, suggesting that the definitive axial identities are established late. These data support the division of planarian development into two separate morphogenetic stages: a highly divergent gastrulation stage, which segregates the three germ layers and establishes the primary organization of the feeding embryo; and subsequent metamorphosis, based on totipotent blastomeres, which establishes the definitive adult body plan using mechanisms that are similar to those used during regeneration and homeostasis in the adult. PMID:20100474

  6. Evolution of Developmental Control Mechanisms Patterns of cell lineage, movement, and migration from germ layer specification to

    E-print Network

    Alwes, Frederike

    from germ layer specification to gastrulation in the amphipod crustacean Parhyale hawaiensis Frederike 20 July 2011 Available online 28 July 2011 Keywords: Cell lineage Regulation Crustacean Gastrulation

  7. 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

  8. DNA methylation profiling of embryonic stem cell differentiation into the three germ layers.

    PubMed

    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. 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

  10. 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

  11. Evolution of Developmental Control Mechanisms Germ layer specification and axial patterning in the embryonic development of the

    E-print Network

    Amaya, Enrique

    in the embryonic development of the freshwater planarian Schmidtea polychroa José María Martín-Durán a, , Enrique Available online 25 January 2010 Keywords: Planarian Embryo Patterning Gastrulation Germ layers Polarity Regeneration Although patterning during regeneration in adult planarians has been studied extensively, very

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

    PubMed Central

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

    2014-01-01

    Mouse embryonic stem cells (mESCs) are clonal populations derived from preimplantation mouse embryos that can be propagated in vitro and, when placed into blastocysts, contribute to all tissues of the embryo and integrate into the normal morphogenetic processes, i.e. they are pluripotent. However, although they can be steered to differentiate in vitro into all cell types of the organism, they cannot organise themselves into structures that resemble embryos. When aggregated into embryoid bodies they develop disorganised masses of different cell types with little spatial coherence. An exception to this rule is the emergence of retinas and anterior cortex-like structures under minimal culture conditions. These structures emerge from the cultures without any axial organisation. Here, we report that small aggregates of mESCs, of about 300 cells, self-organise into polarised structures that exhibit collective behaviours reminiscent of those that cells exhibit in early mouse embryos, including symmetry breaking, axial organisation, germ layer specification and cell behaviour, as well as axis elongation. The responses are signal specific and uncouple processes that in the embryo are tightly associated, such as specification of the anteroposterior axis and anterior neural development, or endoderm specification and axial elongation. We discuss the meaning and implications of these observations and the potential uses of these structures which, because of their behaviour, we suggest to call ‘gastruloids’. PMID:25371360

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

    PubMed Central

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

    2015-01-01

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

  14. 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

  15. 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

  16. 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.

  17. Null Association Between Histology of First and Second Primary Malignancies in Men With Bilateral Testicular Germ Cell Tumors

    PubMed Central

    Thomas, Jennifer Phay Johnson; Davis-Dao, Carol; Lewinger, Juan Pablo; Siegmund, Kimberly D.; Hamilton, Ann S.; Daneshmand, Siamak; Skinner, Eila C.; Thomas, Duncan C.; Cortessis, Victoria K.

    2013-01-01

    Testicular germ cell tumors (TGCTs), the most common neoplasms of young men, are categorized histologically as either seminomas or nonseminomas/mixed germ cell tumors. These subtypes differ by age at diagnosis and clinical course, but little is known about etiological distinctions. To test the hypothesis that histological subtypes have distinct sets of unrecognized etiological factors, we used a recently described approach, estimating the association between histological types of first and second tumors of men with 2 primary TGCTs. The study population of 488 men each with 2 primary TGCTs was ascertained through population-based cancer registries in the United States between 1972 and 2006. Univariate logistic regression analysis revealed that the histology of second primary TGCTs was associated with the histology of first TGCTs (odds ratio = 1.70, 95% confidence interval: 1.14, 2.52); however, the association did not persist in analyses adjusted for age at diagnosis of first TGCT (odds ratio = 1.09, 95% confidence interval: 0.71, 1.70). These results would be expected if the subtypes share etiology but experience different rates of progression to diagnosis or if the histological fate of TGCTs is influenced by age-related processes. Men with 2 primary TGCTs provide novel opportunities to learn whether histological subtypes are likely to share etiology, so results may inform research designed to identify causes. PMID:23928263

  18. [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

  19. 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 ? (PPP2R1A), ring finger protein 43 (RNF43), DNA directed polymerase ? (POLE1), ribonuclease type III (DICER1), CCCTC?binding factor (CTCF), ribosomal protein L22 (RPL22), DNA methyltransferase 3? (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

  20. 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

  1. 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.

  2. 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)

  3. Blastema cells derived from New Zealand white rabbit's pinna carry stemness properties as shown by differentiation into insulin producing, neural, and osteogenic lineages representing three embryonic germ layers.

    PubMed

    Saeinasab, Morvarid; Matin, Maryam M; Rassouli, Fatemeh B; Bahrami, Ahmad Reza

    2014-11-01

    Stem cells (SCs) are known as undifferentiated cells with self-renewal and differentiation capacities. Regeneration is a phenomenon that occurs in a limited number of animals after injury, during which blastema tissue is formed. It has been hypothesized that upon injury, the dedifferentiation of surrounding tissues leads into the appearance of cells with SC characteristics. In present study, stem-like cells (SLCs) were obtained from regenerating tissue of New Zealand white rabbit's pinna and their stemness properties were examined by their capacity to differentiate toward insulin producing cells (IPCs), as well as neural and osteogenic lineages. Differentiation was induced by culture of SLCs in defined medium, and cell fates were monitored by specific staining, RT-PCR and flow cytometry assays. Our results revealed that dithizone positive cells, which represent IPCs, and islet-like structures appeared 1 week after induction of SLCs, and this observation was confirmed by the elevated expression of Ins, Pax6 and Glut4 at mRNA level. Furthermore, SLCs were able to express neural markers as early as 1 week after retinoic acid treatment. Finally, SLCs were able to differentiate into osteogenic lineage, as confirmed by Alizarin Red S staining and RT-PCR studies. In conclusion, SLCs, which could successfully differentiate into cells derived from all three germ layers, can be considered as a valuable model to study developmental biology and regenerative medicine. PMID:25371011

  4. Germs and Staying Healthy

    MedlinePLUS

    ... Clinical Trial Living with CF Germs and Staying Healthy People living with CF are at greater risk ... More Topics Treatments and Therapies Germs and Staying Healthy Navigating Insurance CF and School Advocate CF Clinical ...

  5. General Information about Extragonadal Germ Cell Tumors

    MedlinePLUS

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

  6. Treatment Option Overview (Extragonadal Germ Cell Tumors)

    MedlinePLUS

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

  7. Testicular Germ Cell Cancer

    Cancer.gov

    More than 90 percent of testicular cancer start in the germ cells, which are cells in the testicles and develop into sperm. This type of cancer is known as testicular germ cell cancer. Testicular germ cell cancer can be classified as either seminomas or nonseminomas, whose cells have different appearances under a microscope.1 Another difference is that nonseminomas typically grow and spread more quickly than seminomas.

  8. Dissecting Germ Cell Metabolism through Network Modeling.

    PubMed

    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

  9. Development of Layer-specific Axonal Arborizations in Mouse Primary Somatosensory Cortex

    PubMed Central

    Larsen, DeLaine D.; Callaway, Edward M.

    2015-01-01

    In the developing neocortex, pyramidal neurons use molecular cues to form axonal arbors selectively in the correct layers. Despite the utility of mice for molecular and genetic studies, little work has been done on the development of layer-specific axonal arborizations of pyramidal neurons in mice. We intracellularly labeled and reconstructed the axons of layer 2/3 and layer 5 pyramidal neurons in slices of primary somatosensory cortex from C57Bl6 mice aged postnatal day 7–21. For all neurons studied, the development of the axonal arborizations in mice follows a pattern similar to that seen in other species; laminar specificity of the earliest axonal branches is similar to that of mature animals. At P7, pyramidal neurons are very simple, having only a main descending axon and few primary branches. Between P7 and P10 there is a large increase in the total number of axonal branches and axons continue to increase in complexity and total length from P10 to P21. Unlike observations in ferrets, cats, and monkeys, two types of layer 2/3 pyramidal neurons are present in both mature and developing mice; cells in superficial layer 2/3 lack axonal arbors in layer 4 while cells close to the layer 4 border have substantial axonal arbors within layer 4. We also describe axonal and dendritic arborization patterns of three pyramidal cell types in layer 5. The axons of tall-tufted layer 5 pyramidal neurons arborize almost exclusively within deep layers while tall-simple and short layer 5 pyramidal neurons also project axons to superficial layers. PMID:16320250

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

    E-print Network

    Bortvin, Alex

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

  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. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  14. Genetics of germ cell development

    E-print Network

    Lesch, Bluma J.

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

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. [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

  1. 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

  2. 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. ...

  3. 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

  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. Isometry germs and related structures

    E-print Network

    Ll. Bel

    2004-12-03

    We define an Isometry germ at any given event $x$ of space-time as a vector field $\\xi$ defined in a neighborhood of $x$ such that the Lie derivative of both the metric and the Riemannian connection are zero at this event. Two isometry germs can be said to be equivalent if their values and the values of their first derivatives coincide at $x$. The corresponding quotient space can be endowed with a structure of a bracket algebra which is a deformation of de Sitter's Lie algebra. Each isometry germ defines also a local stationary frame of reference, the consideration of the family of adapted coordinate transformations between any two of them leading to a local novel structure that generalizes the Lorentz group.

  6. Dazl regulates mouse embryonic germ cell development

    E-print Network

    Gill, Mark E

    2010-01-01

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

  7. 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

  8. 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...

  9. Identification of Potential Germ-Cell Mutagens

    EPA Science Inventory

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

  10. 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…

  11. 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

  12. 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

  13. The Geochemical Earth Reference Model (GERM)

    SciTech Connect

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

    1996-12-01

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

  14. 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.

  15. 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.

  16. 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

  17. Light and electron microscopic analyses of Vasa expression in adult germ cells of the fish medaka.

    PubMed

    Yuan, Yongming; Li, Mingyou; Hong, Yunhan

    2014-07-15

    Germ cells of diverse animal species have a unique membrane-less organelle called germ plasm (GP). GP is usually associated with mitochondria and contains RNA binding proteins and mRNAs of germ genes such as vasa. GP has been described as the mitochondrial cloud (MC), intermitochondrial cement (IC) and chromatoid body (CB). The mechanism underlying varying GP structures has remained incompletely understood. Here we report the analysis of GP through light and electron microscopy by using Vasa as a marker in adult male germ cells of the fish medaka (Oryzias latipes). Immunofluorescence light microscopy revealed germ cell-specific Vasa expression. Vasa is the most abundant in mitotic germ cells (oogonia and spermatogonia) and reduced in meiotic germ cells. Vasa in round spermatids exist as a spherical structure reminiscent of CB. Nanogold immunoelectron microscopy revealed subcellular Vasa redistribution in male germ cells. Vasa in spermatogonia concentrates in small areas of the cytoplasm and is surrounded by mitochondria, which is reminiscent of MC. Vasa is intermixed with mitochondria to form IC in primary spermatocytes, appears as the free cement (FC) via separation from mitochondria in secondary spermatocyte and becomes condensed in CB at the caudal pole of round spermatids. During spermatid morphogenesis, Vasa redistributes and forms a second CB that is a ring-like structure surrounding the dense fiber of the flagellum in the midpiece. These structures resemble those described for GP in various species. Thus, Vasa identifies GP and adopts varying structures via dynamic reorganization at different stages of germ cell development. PMID:24814190

  18. 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

  19. 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

  20. 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

  1. Germ cell specification and regeneration in planarians.

    PubMed

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

    2008-01-01

    In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work. PMID:19022767

  2. Introduction Germ cell segregation is an important problem in

    E-print Network

    Extavour, Cassandra

    of disagreement as to how germ cells may be identified, and when in development the germ line is specified lineage throughout the animal kingdom. There are at least two distinct modes of germ line segregation divisions; these cells are called germ line stem cells. The first cells that will give rise exclusively

  3. Layers

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    The temperature-dependent photoresponse characteristics of MnAl2S4 layers have been investigated, for the first time, by use of photocurrent (PC) spectroscopy. Three peaks were observed at all temperatures. The electronic origin of these peaks was associated with band-to-band transitions from the valence-band states ?4( z), ?5( x), and ?5( y) to the conduction-band state ?1( s). On the basis of the relationship between PC-peak energy and temperature, the optical band gap could be well expressed by the expression E g( T) = E g(0) - 2.80 × 10-4 T 2/(287 + T), where E g(0) was estimated to be 3.7920 eV, 3.7955 eV, and 3.8354 eV for the valence-band states ?4( z), ?5( x), and ?5( y), respectively. Results from PC spectroscopy revealed the crystal-field and spin-orbit splitting were 3.5 meV and 39.9 meV. The gradual decrease of PC intensity with decreasing temperature can be explained on the basis of trapping centers associated with native defects in the MnAl2S4 layers. Plots of log J ph, the PC current density, against 1/ T, revealed a dominant trap level in the high-temperature region. By comparing PC and the Hall effect results, we confirmed that this trap level is a shallow donor 18.9 meV below the conduction band.

  4. 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

  5. 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

  6. Poised chromatin in the mammalian germ line.

    PubMed

    Lesch, Bluma J; Page, David C

    2014-10-01

    Poised (bivalent) chromatin is defined by the simultaneous presence of histone modifications associated with both gene activation and repression. This epigenetic feature was first observed at promoters of lineage-specific regulatory genes in embryonic stem cells in culture. More recent work has shown that, in vivo, mammalian germ cells maintain poised chromatin at promoters of many genes that regulate somatic development, and that they retain this state from fetal stages through meiosis and gametogenesis. We hypothesize that the poised chromatin state is essential for germ cell identity and function. We propose three roles for poised chromatin in the mammalian germ line: prevention of DNA methylation, maintenance of germ cell identity and preparation for totipotency. We discuss these roles in the context of recently proposed models for germline potency and epigenetic inheritance. PMID:25249456

  7. 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

  8. Human amniotic epithelial cells differentiate into cells expressing germ cell specific markers when cultured in medium containing serum substitute supplement

    PubMed Central

    2012-01-01

    Background Human amniotic epithelial cells (hAECs) maintain the plasticity of pregastrulation embryonic cells, having the potential to differentiate into all three germ layers. The potential of these cells to differentiate into cells expressing germ cell specific markers has never been described before. Methods In the present study, hAECs were cultured in medium containing serum substitute supplement (SSS). Gene and protein expression of germ cell and oocyte specific markers was assessed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and flow activated cell sorter analysis (FACS) in hAECs at different time points during the differentiation into cells expressing germ cell specific markers. Results When cultured with SSS, already at passage 1, hAECs start to express the germ cell specific genes C-KIT, DAZL, VASA and ZP3 and at passage 5 large round cells, resembling oocytes, appeared. The cells express the germ cell specific marker DAZL, the oocyte specific markers GDF9 and ZP3 and the meiosis specific markers DMC1 and SCP3 at the protein level. Conclusions From our preliminary results we can conclude that hAECs have the potential to differentiate into cells expressing germ cell specific markers. PMID:23241213

  9. Seasonal variability of primary production and phytoplankton biomass in the western Pacific subarctic gyre: Control by light availability within the mixed layer

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kazuhiko; Honda, Makio C.; Sasaoka, Kosei; Wakita, Masahide; Kawakami, Hajime; Watanabe, Shuichi

    2014-09-01

    A distinct seasonal variation of primary production was revealed from shipboard observations conducted from 2005 to 2013 at time series station K2 in the western Pacific subarctic gyre (WSG). The mean depth-integrated primary production was highest (569 ± 162 mg C m-2 d-1) in summer and lowest (101 ± 16 mg C m-2 d-1) in winter. Strong winter mixing enriched the mixed layer (ML) with nutrients that were not fully consumed during the remainder of the year, the result being that the WSG was a high-nutrient, low-chlorophyll (HNLC) region. The deep ML reduced primary production by reducing light availability in winter, whereas primary production was enhanced by strong light availability in the shallower ML as summer progressed. However, primary production was often attenuated by a reduction of light availability attributable to dense sea fog in summer. We found a significant relationship between primary production and light availability in this HNLC region. However, chlorophyll a was less variable seasonally than primary production. The highest depth-integrated chlorophyll a was observed in summer (54.6 ± 13.4 mg m-2), but chlorophyll a remained high in winter (45.3 ± 7.7 mg m-2). Reduced light availability depressed primary production, but a reduction of the chlorophyll a concentration was prevented by a relaxation of grazing in the deep ML during winter. We found that light availability exerted an important control on the seasonal variability of primary production and phytoplankton biomass in the WSG.

  10. 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

  11. 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

  12. 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

  13. 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

  14. "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

  15. 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

  16. Enhanced genetic integrity in mouse germ cells.

    PubMed

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

    2013-01-01

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

  17. 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.

  18. Eight Ways to Guard Against Germs in Everyday Life

    MedlinePLUS

    ... are two disinfecting options: heat and cold methods. Heat Methods: Boil for 5 minutes Microwave for 5 ... these germs if you breathe them in or transfer the germs by touching your eyes, nose or ...

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

    E-print Network

    Angulo,Jesús

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

  20. 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.

  1. Prospects & Overviews Vasa genes: Emerging roles in the germ

    E-print Network

    Wessel, Gary M.

    Prospects & Overviews Vasa genes: Emerging roles in the germ line and in multipotent cells Eric A molecular determinants act in this germ line maintenance and function. The most universal of these genes function in other cell types, distinct from the germ line. Here we evaluate our current understanding

  2. 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...

  3. 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...

  4. Germ cell nuclear factor is not required for the down-regulation of pluripotency markers in fetal ovarian germ cells

    E-print Network

    Okumura, Leah M

    2012-01-01

    In mouse, germ cells retain expression of the pluripotency markers Oct4 and Nanog longer than any other cells in the body. While somatic cells repress these markers during gastrulation, female germ cells continue to express ...

  5. 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

  6. 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.

  7. 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,…

  8. 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…

  9. 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...

  10. Nodal/Cripto signaling in fetal male germ cell development: implications for testicular germ cell tumors.

    PubMed

    Spiller, Cassy M; Bowles, Josephine; Koopman, Peter

    2013-01-01

    Testicular cancer is the most frequent cancer in young men aged 15-40 years and accounts for 1% of all cancer diagnosed in males. Testicular germ cell tumors (TGCT) encompass a broad group of cancers, each displaying different levels of pluripotency and differentiation as well as malignancy potential. The TGCT cell of origin is thought to be a fetal germ cell that failed to correctly differentiate during development: this is known as the ?fetal origins hypothesis?. This theory predicts that developmental pathways that control germ cell pluripotency or differentiation may be involved in the malignant transformation of these cells. Recently the Nodal/Cripto signaling pathway, known to control pluripotency and differentiation in embryonic stem (ES) cells, was implicated in regulating normal male fetal germ cell pluripotency. Although genes of this pathway are not normally expressed in germ cells during adult life, ectopic expression of this pathway was detected in several sub-groups of TGCTs. In this review, we consider the evidence for the fetal origins of TGCT and discuss the implications of Nodal/Cripto signaling in various aspects of germ cell development and cancer progression. PMID:23784832

  11. 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

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

    PubMed Central

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

    2014-01-01

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

  13. 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

  14. 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. Biotechnol. Bioeng. 2015;112: 2571-2582. © 2015 Wiley Periodicals, Inc. PMID:25994312

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

    PubMed

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

    2015-07-01

    Management of germ free animals has changed little since the beginning of the 20th century. The current upswing in their use, however, has led to interest in improved methods of screening and housing. Traditionally, germ free colonies are screened for bacterial colonization by culture and examination of Gram stained fecal samples, but some investigators have reported using PCR-based methods of microbial detection, presumably because of perceived increased sensitivity. The accuracy and detection limit for traditional compared to PCR-based screening assays are not known. The purpose of this study was to determine the limit of detection of bacterial contamination of mouse feces by aerobic and anaerobic culture, Gram stain, and qPCR, and to compare the accuracy of these tests in the context of a working germ free mouse colony. We found that the limit of detection for qPCR (approximately 10(5) cfu/g of feces) was lower than for Gram stain (approximately 10(9) cfu/g), but that all 3 assays were of similar accuracy. Bacterial culture was the most sensitive, but the least specific, and qPCR was the least sensitive and most specific. Gram stain but not qPCR detected heat-killed bacteria, indicating that bacteria in autoclaved diet are unlikely to represent a potential confounding factor for PCR screening. We conclude that as a practical matter, bacterial culture and Gram stain are adequate for screening germ free mouse colonies for bacterial contaminants, but that should low numbers of unculturable bacteria be present, they would not be detected with any of the currently available means. PMID:26018301

  17. 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

  18. 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

  19. Complex Maslov germs in abstract spaces

    NASA Astrophysics Data System (ADS)

    Shvedov, O. Yu

    1999-10-01

    For various evolution equations for an element of a Hilbert space one uses different asymptotic methods to construct approximate solutions of these equations, which are expressed in terms of points (that are time-dependent and satisfy certain equations) in a smooth manifold {\\mathscr Y} and elements of a Hilbert space {\\mathscr F}_y. In the present paper the properties of asymptotic solutions are studied under fairly general assumptions on the map associating a pair y\\in {\\mathscr Y}, f\\in {\\mathscr F}_y with an asymptotic formula. An analogue of the concept of complex Maslov germ is introduced in the abstract case and its properties are studied. An analogue of the theory of Lagrangian manifolds with complex germ is discussed. The connection between the existence of an invariant complex germ and the stability of the solution of the equation for a point in the smooth manifold {\\mathscr Y} is investigated. The results so obtained can be used for the construction and geometric interpretation of new asymptotic solutions of evolution equations in the case when some class of asymptotic solutions is already known.

  20. Complex Maslov germs in abstract spaces

    SciTech Connect

    Shvedov, O Yu

    1999-10-31

    For various evolution equations for an element of a Hilbert space one uses different asymptotic methods to construct approximate solutions of these equations, which are expressed in terms of points (that are time-dependent and satisfy certain equations) in a smooth manifold Y and elements of a Hilbert space F{sub y}. In the present paper the properties of asymptotic solutions are studied under fairly general assumptions on the map associating a pair y element of Y, f element of F{sub y} with an asymptotic formula. An analogue of the concept of complex Maslov germ is introduced in the abstract case and its properties are studied. An analogue of the theory of Lagrangian manifolds with complex germ is discussed. The connection between the existence of an invariant complex germ and the stability of the solution of the equation for a point in the smooth manifold Y is investigated. The results so obtained can be used for the construction and geometric interpretation of new asymptotic solutions of evolution equations in the case when some class of asymptotic solutions is already known.

  1. Synchronous Chaos and Broad Band Gamma Rhythm in a Minimal Multi-Layer Model of Primary Visual Cortex

    PubMed Central

    Battaglia, Demian; Hansel, David

    2011-01-01

    Visually induced neuronal activity in V1 displays a marked gamma-band component which is modulated by stimulus properties. It has been argued that synchronized oscillations contribute to these gamma-band activity. However, analysis of Local Field Potentials (LFPs) across different experiments reveals considerable diversity in the degree of oscillatory behavior of this induced activity. Contrast-dependent power enhancements can indeed occur over a broad band in the gamma frequency range and spectral peaks may not arise at all. Furthermore, even when oscillations are observed, they undergo temporal decorrelation over very few cycles. This is not easily accounted for in previous network modeling of gamma oscillations. We argue here that interactions between cortical layers can be responsible for this fast decorrelation. We study a model of a V1 hypercolumn, embedding a simplified description of the multi-layered structure of the cortex. When the stimulus contrast is low, the induced activity is only weakly synchronous and the network resonates transiently without developing collective oscillations. When the contrast is high, on the other hand, the induced activity undergoes synchronous oscillations with an irregular spatiotemporal structure expressing a synchronous chaotic state. As a consequence the population activity undergoes fast temporal decorrelation, with concomitant rapid damping of the oscillations in LFPs autocorrelograms and peak broadening in LFPs power spectra. We show that the strength of the inter-layer coupling crucially affects this spatiotemporal structure. We predict that layer VI inactivation should induce global changes in the spectral properties of induced LFPs, reflecting their slower temporal decorrelation in the absence of inter-layer feedback. Finally, we argue that the mechanism underlying the emergence of synchronous chaos in our model is in fact very general. It stems from the fact that gamma oscillations induced by local delayed inhibition tend to develop chaos when coupled by sufficiently strong excitation. PMID:21998568

  2. 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

  3. 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 ...

  4. 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

  5. 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

  6. 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.

  7. Fine-tuning evolution: germ-line epigenetics and inheritance.

    PubMed

    Stringer, Jessica M; Barrand, Sanna; Western, Patrick

    2013-07-01

    In mice, epiblast cells found both the germ-line and somatic lineages in the developing embryo. These epiblast cells carry epigenetic information from both parents that is required for development and cell function in the fetus and during post-natal life. However, germ cells must establish an epigenetic program that supports totipotency and the configuration of parent-specific epigenetic states in the gametes. To achieve this, the epigenetic information inherited by the primordial germ cells at specification is erased and new epigenetic states are established during development of the male and female germ-lines. Errors in this process can lead to transmission of epimutations through the germ-line, which have the potential to affect development and disease in the parent's progeny. This review discusses epigenetic reprogramming in the germ-line and the transmission of epigenetic information to the following generation. PMID:23633622

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

    PubMed

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

    2015-04-01

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

  9. 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

  10. 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.

  11. Mixed germ cell tumor of ovary and clitoromegaly in Swyer's syndrome: a case report.

    PubMed

    Aminimoghaddam, S; Mokri, B; Mahmoodzadeh, F

    2012-07-01

    Swyer syndrome is a type of pure gonadal dysgenesis correlating with 46 XY karyotype, primary amenorrhea, and female internal and external genitalia. It reveals a testicular differentiation abnormality.A 16-year old girl admitted to our center with primary amenorrhea and abdominal mass. In spite of the absence of normal testis, clitoromegaly was noticed. Peripheral blood karyotype analysis showed 46 XY. Histopathology of the excised gonads determined mixed germ cell tumor in right ovary and streak left gonad without gonadoblastoma in left side. In patients suffering from Swyer syndrome, high risk of gonadal neoplasia dictates early prophylactic gonadal excision to lengthen survival. PMID:22773216

  12. 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.

  13. 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.

  14. 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

  15. 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.

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

    ClinicalTrials.gov

    2014-12-23

    Cognitive Side Effects of Cancer Therapy; Malignant Ovarian Mixed Epithelial Tumor; Malignant Ovarian Surface Epithelial-Stromal 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

  17. The epigenetic regulator PLZF represses L1 retrotransposition in germ and progenitor cells.

    PubMed

    Puszyk, William; Down, Thomas; Grimwade, David; Chomienne, Christine; Oakey, Rebecca J; Solomon, Ellen; Guidez, Fabien

    2013-07-01

    Germ cells and adult stem cells maintain tissue homeostasis through a finely tuned program of responses to both physiological and stress-related signals. PLZF (Promyelocytic Leukemia Zinc Finger protein), a member of the POK family of transcription factors, acts as an epigenetic regulator of stem cell maintenance in germ cells and haematopoietic stem cells. We identified L1 retrotransposons as the primary targets of PLZF. PLZF-mediated DNA methylation induces silencing of the full-length L1 gene and inhibits L1 retrotransposition. Furthermore, PLZF causes the formation of barrier-type boundaries by acting on inserted truncated L1 sequences in protein coding genes. Cell stress releases PLZF-mediated repression, resulting in L1 activation/retrotransposition and impaired spermatogenesis and myelopoiesis. These results reveal a novel mechanism of action by which, PLZF represses retrotransposons, safeguarding normal progenitor homeostasis. PMID:23727884

  18. 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.

  19. 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

  20. 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.

  1. Prognostic factors in metastatic germ cell tumors.

    PubMed

    Schmoll, H J; Beyer, J

    1998-04-01

    Metastatic germ cell cancer is a very heterogeneous group with respect to prognosis under cisplatinum-based chemotherapy. The main determinants of complete response and survival are not only the extension of the metastases but much more the biology of the underlying tumor which is represented by the location of the metastases (pulmonary versus nonpulmonary visceral metastases (liver, bone, central nervous system) and the level of the marker elevation (AFG, HCG, LDH). Using these parameters patients with seminoma can be in two or three prognostic divided groups, depending on the model used; nonseminomatous germ cell cancer can be divided in three prognostic groups (good, intermediate and poor prognosis) with a 5 year survival of 90%, 70%, and 50%, respectively. The rate of marker decline and AFP- "surge" are not proven to be significant indicators of prognosis after the start of chemotherapy. Also, molecular markers i12p, p53, Rb, DNA-repair-capacity, etc, currently do not contribute to the prognostic models. In conclusion, with the present available prognostic models the patients with seminomatous as well as nonseminomatous cancer can be attributed to different prognostic groups for first-line as well as salvage treatment. This allows to the selection of patients for a risk adapted treatment and for the investigation of less toxic regimen for good prognosis patients and more aggressive protocols for intermediate and in particular poor risk patients. PMID:9562450

  2. Everyday Preventive Actions That Can Help Fight Germs, Like Flu

    E-print Network

    Capecchi, Mario R.

    are not available, use an alcohol-based hand rub. Avoid touching your eyes, nose, and mouth.y Germs spread this way supply ofy tissues, soap, paper towels, alcohol-based hand rubs, and disposable wipes. Train others or nose that could contain germs. Wash your hands often with soap andy water. If soap and water

  3. 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...

  4. Cellular Mechanics of Germ Band Retraction in Drosophila

    PubMed Central

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

    2013-01-01

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

  5. 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

  6. Germ line control of female sex determination in zebrafish.

    PubMed

    Siegfried, Kellee R; Nüsslein-Volhard, Christiane

    2008-12-15

    A major transition during development of the gonad is commitment from an undifferentiated "bi-potential" state to ovary or testis fate. In mammals, the oogonia of the developing ovary are known to be important for folliculogenesis. An additional role in promoting ovary fate or female sex determination has been suggested, however it remains unclear how the germ line might regulate this process. Here we show that the germ line is required for the ovary versus testis fate choice in zebrafish. When the germ line is absent, the gonad adopts testis fate. These germ line deficient testes have normal somatic structures indicating that the germ line influences fate determination of surrounding somatic tissues. In germ line deficient animals the expression of the ovary specific gene cyp19a1a fails to be maintained whereas the testis genes sox9a and amh remain expressed. Furthermore, we observed decreased levels of the ovary specific genes cyp19a1a and foxL2 in germ line deficient animals prior to morphological sex differentiation of the gonad. We propose that the germ line has a common role in female sex determination in fish and mammals. Additionally, we show that testis specification is sufficient for masculinization of the fish pointing to a direct role of hormone signaling from the gonad in directing sex differentiation of non-gonadal tissues. PMID:18930041

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Zebrafish germ cells: motility and guided migration.

    PubMed

    Paksa, Azadeh; Raz, Erez

    2015-10-01

    In the course of embryonic development, the process of cell migration is critical for establishment of the embryonic body plan, for morphogenesis and for organ function. Investigating the molecular mechanisms underlying cell migration is thus crucial for understanding developmental processes and clinical conditions resulting from abnormal cell migration such as cancer metastasis. The long-range migration of primordial germ cells toward the region at which the gonad develops occurs in embryos of various species and thus constitutes a useful in vivo model for single-cell migration. Recent studies employing zebrafish embryos have greatly contributed to the understanding of the mechanisms facilitating the migration of these cells en route to their target. PMID:26232877

  14. 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

  15. 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

  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. Temporal and spatial control of germ-plasm RNAs.

    PubMed

    Rangan, Prashanth; DeGennaro, Matthew; Jaime-Bustamante, Kean; Coux, Rémi-Xavier; Martinho, Rui G; Lehmann, Ruth

    2009-01-13

    In many species, germ cells form in a specialized germ plasm, which contains localized maternal RNAs. In the absence of active transcription in early germ cells, these maternal RNAs encode germ-cell components with critical functions in germ-cell specification, migration, and development. For several RNAs, localization has been correlated with release from translational repression, suggesting an important regulatory function linked to localization. To address the role of RNA localization and translational control more systematically, we assembled a comprehensive set of RNAs that are localized to polar granules, the characteristic germ-plasm organelles. We find that the 3'-untranslated regions (UTRs) of all RNAs tested control RNA localization and instruct distinct temporal patterns of translation of the localized RNAs. We demonstrate necessity for translational timing by swapping the 3'UTR of polar granule component (pgc), which controls translation in germ cells, with that of nanos, which is translated earlier. Translational activation of pgc is concurrent with extension of its poly(A) tail length but appears largely independent of the Drosophila CPEB homolog ORB. Our results demonstrate a role for 3'UTR mediated translational regulation in fine-tuning the temporal expression of localized RNA, and this may provide a paradigm for other RNAs that are found enriched at distinct cellular locations such as the leading edge of fibroblasts or the neuronal synapse. PMID:19110432

  18. 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

  19. 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.

  20. 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

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

    PubMed

    Okamoto, Keisei

    2012-06-01

    Testicular germ cell tumors are neoplasms carrying two unique features. First, testicular germ cell tumors have a pluripotential nature and show protean histology ranging from that of germ cells to embryonal and differentiated somatic cells. Therefore, testicular germ cell tumors are interesting resources positioned at a crossroad in developmental and neoplastic processes. The second unique feature of testicular germ cell tumors is their exquisite sensitivity to cisplatin-based chemotherapy. This review summarizes recent research progress in the epigenetics of testicular germ cell tumors in an attempt to explain the abovementioned biological and clinical characteristics of testicular germ cell tumors. PMID:22375557

  2. Edinburgh Research Explorer Meiosis and retrotransposon silencing during germ cell

    E-print Network

    Millar, Andrew J.

    Edinburgh Research Explorer Meiosis and retrotransposon silencing during germ cell development in mice Citation for published version: Oellinger, R, Reichmann, J & Adams, IR 2010, 'Meiosis immediately and investigate your claim. Download date: 05. Jul. 2015 #12;Meiosis and retrotransposon silencing

  3. Developmental transitions of germ cell lineage of the mouse

    E-print Network

    Baltus, Andrew Edmund

    2006-01-01

    Mammalian germ cells arise during early embryogenesis and migrate to the developing gonad where, under the direction of the somatic environment, they initiate distinct sex-specific developmental programs resulting in the ...

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

    MedlinePLUS

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

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

    MedlinePLUS

    ... this? Submit Button Past Newsletters Preventing the Flu: Good Health Habits Can Help Stop Germs Language: English ... her eyes, nose, or mouth. 6. Practice other good health habits. Clean and disinfect frequently touched surfaces ...

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

    MedlinePLUS

    ... before the cancer is diagnosed and continue for months or years. Childhood CNS germ cell tumors may ... after treatment. Some cancer treatments cause side effects months or years after treatment has ended. Some cancer ...

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

    MedlinePLUS

    ... before the cancer is diagnosed and continue for months or years. Childhood CNS germ cell tumors may ... after treatment. Some cancer treatments cause side effects months or years after treatment has ended. Some cancer ...

  8. On the stability of analytic germs under ultradifferentiable perturbations

    NASA Astrophysics Data System (ADS)

    Thilliez, Vincent

    2007-04-01

    Let f be a real-analytic function germ at the origin in , whose critical locus contains a given real-analytic set X, and let Y be a germ of a closed subset at the origin. We study the stability of f under perturbations u that are flat on Y and that belong to a given Denjoy-Carleman non-quasianalytic class. We obtain a condition ensuring that f+u=f[circle, open][Phi] where [Phi] is a germ of diffeomorphism whose components belong to a (generally larger) Denjoy-Carleman class. Roughly speaking, this condition involves a Lojasiewicz-type separation property between Y and the complex zeros of a certain ideal associated with f and X. The relationship between the Denjoy-Carleman classes of u and [Phi] is controlled precisely by the inequality. This result extends, and simplifies, former work of the author on germs with isolated critical points.

  9. 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

  10. 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.

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

    E-print Network

    Heninger, Noah Leland, III

    2007-04-25

    separately been shown to increase germ cell losses during spermatogenesis [71,92-94]. One 4-yr-old Thoroughbred stallion with normal testes size and semen quality was selected for orchiectomy under general anesthesia during the breeding season (August...). One (left) testis was surgically removed to serve as a control prior to treatment. Post-surgical swelling of the scrotum was expected to induce heat-related testicular germ cell loss. Immediately following recovery from anesthesia, four 2.1 mg...

  12. 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 ?gt10 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

  13. Conversion of midbodies into germ cell intercellular bridges

    PubMed Central

    Greenbaum, Michael P.; Ma, Lang; Matzuk, Martin M.

    2009-01-01

    Whereas somatic cell cytokinesis resolves with abscission of the midbody, resulting in independent daughter cells, germ cell cytokinesis concludes with the formation of a stable intercellular bridge interconnecting daughter cells in a syncytium. While many proteins essential for abscission have been discovered, until recently, no proteins essential for mammalian germ cell intercellular bridge formation have been identified. Using TEX14 as a marker for the germ cell intercellular bridge, we show that TEX14 co-localizes with the centralspindlin complex, mitotic kinesin-like protein 1 (MKLP1) and male germ cell Rac GTPase-activating protein (MgcRacGAP), and converts these midbody matrix proteins into stable intercellular bridge components. In contrast, septins (SEPT) 2, 7, and 9 are transitional proteins in the newly forming bridge. In cultured somatic cells, TEX14 can localize to the midbody in the absence of other germ cell specific factors, suggesting that TEX14 serves to bridge the somatic cytokinesis machinery to other germ cell proteins to form a stable intercellular bridge essential for male reproduction. PMID:17383626

  14. 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-?) 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

  15. Stem cell research points the way to the cell of origin for intracranial germ cell tumours.

    PubMed

    Tan, Chris; Scotting, Paul J

    2013-01-01

    Germ cell tumours found in the brain (intracranial GCTs) are a very unusual class of tumour for two reasons. First, they include a very diverse range of histological subtypes classified together due to their proposed common cell of origin. Second, this proposed cell of origin, the germ cell progenitor, would not normally be found in the tissue where these tumours arise. This is in contrast to all other primary brain tumours, in which the cell of origin is believed to be a brain cell. Indeed, no other class of primary cancer arises from a cell from a distant organ. This theory for the origins of intracranial GCTs has been in place for many decades, but recent data arising from studies of induced pluripotency for regenerative medicine raise serious questions about this dogma. Here we review the cellular origins of intracranial GCTs in the light of these new data and reanalyse the existing data on the biology of this unusual class of tumours. Together, these considerations lead us to conclude that the evidence now falls in favour of a model in which these tumours arise from the transformation of endogenous brain cells. This theory should inform future studies of the aetiology of these tumours and so lead the way to animal models in which to study their development and potential biological therapeutics. PMID:22926997

  16. 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

  17. Hormonal control of germ cell development and spermatogenesis.

    PubMed

    O'Shaughnessy, Peter J

    2014-05-01

    Spermatogenesis is completely dependent on the pituitary hormone follicle-stimulating hormone (FSH) and androgens locally produced in response to luteinising hormone (LH). This dual control has been known since the 1930s and 1940s but more recent work, particularly using transgenic mice, has allowed us to determine which parts of the spermatogenic pathway are regulated by each hormone. During the first spermatogenic cycle after puberty both FSH and androgen act to limit the massive wave of germ cell apoptosis which occurs at this time. The established role of FSH in all cycles is to increase spermatogonial and subsequent spermatocyte numbers with a likely effect also on spermiation. Mice lacking FSH or its receptor are fertile, albeit with reduced germ cell numbers, and so this hormone is not an essential regulator of spermatogenesis but acts to optimise germ cell production Androgens also appear to regulate spermatogonial proliferation but, crucially, they are also required to allow spermatocytes to complete meiosis and form spermatids. Animals lacking androgen receptors fail to generate post-meiotic germ cells, therefore, and are infertile. There is also strong evidence that androgens act to ensure appropriate spermiation of mature spermatids. Androgen regulation of spermatogenesis is dependent upon action on the Sertoli cell but recent studies have shown that androgenic stimulation of the peritubular myoid cells is also essential for normal germ cells development. While FSH or androgen alone will both stimulate germ cell development, together they act synergistically to maximise germ cell number. The other hormones/local factors which can regulate spermatogenesis include activins and estrogens although their role in normal physiological regulation of this process needs to be more clearly established. Regulation of spermatogenesis in primates appears to be similar to that in rodents although the role of FSH may be greater. While our knowledge of hormone function during spermatogenesis is now well developed we still lack understanding of the mechanisms by which these hormones act to regulate this process. PMID:24598767

  18. Hyperthermostable surface layer protein tetrabrachion from the archaebacterium Staphylothermus marinus: evidence for the presence of a right-handed coiled coil derived from the primary structure.

    PubMed

    Peters, J; Baumeister, W; Lupas, A

    1996-04-19

    The scaffold of the surface layer covering the hyperthermophilic archaebacterium Staphylothermus marinus is formed by an extended filiform glycoprotein complex, tetrabrachion, which is anchored in the cell membrane at one end of a 70 nm stalk and branches at the other end into four arms of 24 nm length. The arms from a canopy-like meshwork by end-to-end contacts, enclosing a "quasi-periplasmic space". The primary structure of the complex, obtained by an approach based entirely on the polymerase chain reaction, shows that the light and the heavy chains are encoded in this order in a single gene and are generated by internal proteolytic cleavage. One light chain associates with the N-terminal part of a heavy chain to form one of the four arms of the complex, comprising about 1000 residues. Following a glycine-rich linker of about ten residues, the C-terminal 500 residues of the four heavy chains converge to form a four-stranded parallel coiled coil, which ends in a transmembrane segment. The sequence of the coiled coil is exceptional in that the heptad repeat of hydrophobic residues typical for left-handed coiled coils shifts to an undecad repeat after an internal proline residue, indicating that the C-terminal part of the sequence forms a right-handed coiled coil. Such a periodicity has not been detected in coiled coils to date. The almost flawless pattern of aliphatic residues, mainly leucine and isoleucine, throughout the hydrophobic core of the stalk provide one explanation for its exceptional stability. PMID:8632466

  19. 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

  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. Consensus on the management of intracranial germ-cell tumours.

    PubMed

    Murray, Matthew J; Bartels, Ute; Nishikawa, Ryo; Fangusaro, Jason; Matsutani, Masao; Nicholson, James C

    2015-09-01

    The management of intracranial germ-cell tumours is complex because of varied clinical presentations, tumour sites, treatments and outcomes, and the need for multidisciplinary input. Participants of the 2013 Third International CNS Germ Cell Tumour Symposium (Cambridge, UK) agreed to undertake a multidisciplinary Delphi process to identify consensus in the clinical management of intracranial germ-cell tumours. 77 delegates from the symposium were selected as suitable experts in the field and were invited to participate in the Delphi survey, of which 64 (83%) responded to the invitation. Invited participants represented multiple disciplines from Asia, Australasia, Europe, and the Americas. 38 consensus statements encompassing aspects of intracranial germ-cell tumour work-up, staging, treatment, and follow-up were prepared. To achieve consensus, statements required at least 70% agreement from at least 60% of respondents. Overall, 34 (89%) of 38 statements met consensus criteria. This international Delphi approach has defined key areas of consensus that will help guide and streamline clinical management of patients with intracranial germ-cell tumours. Additionally, the Delphi approach identified areas of different understanding and clinical practice internationally in the management of these tumours, areas which should be the focus of future collaborative studies. Such efforts should translate into improved patient outcomes. PMID:26370356

  2. 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

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

    PubMed Central

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

    2014-01-01

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

  4. Germ Cell Migration across Sertoli Cell Tight Junctions

    PubMed Central

    Smith, Benjamin E.; Braun, Robert E.

    2013-01-01

    The blood-testis barrier includes strands of tight junctions between somatic Sertoli cells that restricts solutes from crossing the paracellular space, creating a microenvironment within seminiferous tubules and providing immune privilege to meiotic and postmeiotic cells. Large cysts of germ cells transit the Sertoli cell tight junctions (SCTJs) without compromising their integrity. We used confocal microscopy to visualize SCTJ components during germ cell cyst migration across the SCTJs. Cysts become enclosed within a network of transient compartments fully bounded by old and new tight junctions. Dissolution of the old tight junctions releases the germ cells into the adluminal compartment, thus completing transit across the blood-testis barrier. Claudin 3, a tight junction protein, is transiently incorporated into new tight junctions and then replaced by claudin 11. PMID:22997133

  5. Homotopy type of disentanglements of multi-germs

    NASA Astrophysics Data System (ADS)

    Houston, Kevin

    2009-05-01

    For a complex analytic map f from n-space to p-space with n

    germs it is known that the disentanglement is a wedge of spheres of possibly varying dimensions. In this paper we give a condition that allows us to deduce that the same is true for a large class of multi-germs.

  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. Course No: GERM 2XXX Title: The Environment in German Culture

    E-print Network

    Alpay, S. Pamir

    Course No: GERM 2XXX Credits: 3 Title: The Environment in German Culture Contact: Friedemann J Weidauer Content Area: CA 1 Catalog Copy: GERM 2xxx The Environment in German Culture, Spring, 3 credits, 3

  8. Fetal germ cell differentiation and the impact of the somatic cells 

    E-print Network

    Cowan, Gillian

    2009-01-01

    Specification of a germ cell lineage and appropriate maturation are essential for the transfer of genetic information from one generation to the next. Germ cells form from pluripotent precursor cells that migrate into ...

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

    E-print Network

    Koubová, Jana C

    2007-01-01

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

  10. 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

  11. HiTrap Affinity columns HiTrap Wheat Germ Lectin, 1 ml INSTRUCTIONS

    E-print Network

    Lebendiker, Mario

    HiTrap Affinity columns HiTrap Wheat Germ Lectin, 1 ml INSTRUCTIONS HiTrapTM Wheat Germ Lectin , GradiFracTM or FPLCTM . Table 1. Content of HiTrap Wheat Germ Lectin Code No. Designation No. supplied 17-5107-01 HiTrap Wheat Germ Lectin 5x1 ml Connectors Luerlock female/M6 male 1 Luerlock female/M6

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. The DEAD Box RNA Helicase VBH-1 Is Required for Germ Cell Function in C. elegans

    E-print Network

    Blackwell, Keith

    ARTICLE The DEAD Box RNA Helicase VBH-1 Is Required for Germ Cell Function in C. elegans L. Silvia 2007 Summary: Vasa and Belle are conserved DEAD box RNA helicases required for germ cell function-Liss, Inc. Key words: germline; DEAD box RNA helicase; sperm/ oocyte switch INTRODUCTION Germ cells from

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

    ERIC Educational Resources Information Center

    Solomon, Gregg E. A.; Cassimatis, Nicholas L.

    1999-01-01

    Five studies investigated preschoolers' understanding of the biological germ theory of illness compared to that of 6- or 10- to 11-year-olds. Found that the younger the child, the less likely he or she was to judge germs as causes of illness. Studies undermined claim that preschoolers understand germs to be uniquely biological causal agents. (JPB)

  15. 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 ...

  16. GROUP CONFIGURATIONS AND GERMS IN SIMPLE THEORIES ITAY BEN-YAACOV

    E-print Network

    Ben Yaacov, Itaï

    GROUP CONFIGURATIONS AND GERMS IN SIMPLE THEORIES ITAY BEN-YAACOV Abstract. We develop the theory of germs of generic functions in simple theories. Starting with an algebraic quadrangle (or other similar to generalise the theory of germs of generic functions to simple theories, let us first take a closer look

  17. 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

  18. 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

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

    E-print Network

    Grim, Patrick

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

  20. Germs, Genes, and Memes: Function and Fitness Dynamics on Information Networks

    E-print Network

    Grim, Patrick

    Germs, Genes, and Memes: Function and Fitness Dynamics on Information Networks Patrick Grim,1 in terms of three different types of transfer mechanism: germs, genes, and memes. With an emphasis networks and a measure of their comparative fitness. Germ and meme transfer exhibit very different dynamics

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

    E-print Network

    Alwes, Frederike

    is an essential event during the embryonic development of sexually reproducing animals, as germ line cells are uniquely capable of giving rise to the next generation. Animal germ cells arise through either inheritance animals that have been examined, germ cells are specified by inheritance of a specialized cyto- plasm

  2. 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

  3. 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

  4. Identification of a retinoic acid-sensitive period during primary axis formation in Xenopus laevis.

    PubMed

    Sive, H L; Draper, B W; Harland, R M; Weintraub, H

    1990-06-01

    Retinoic acid (RA) is able to profoundly alter patterning of the primary body axis in embryos of the frog Xenopus laevis. The response to RA is dose-dependent, and leads to progressive truncation of the anteroposterior axis, with anterior structures most sensitive. Both mesodermal and ectodermal tissues are affected, and in vitro assays demonstrate that induced dorsal ectoderm is one direct target of RA. RA represses expression of anterior-specific genes and concomitantly induces expression of at least one posterior-specific gene. Resistance to RA is acquired gradually, during gastrula and early neurula stages, with posterior structures becoming resistant before anterior structures. These data demarcate in the embryo an anterior "domain," which may define the head rudiment and which transcends germ layers. RA can alter the axial pattern after its initial induction; thus, RA sensitivity defines a labile intermediate that occurs during axial patterning. These data suggest a possible role for RA in normal axis formation. PMID:2384214

  5. Hand WashingHand Washing Germ Fighting 101

    E-print Network

    time. Rub your hands together vigorously. Work into a lather from wrist to fingertip. Scrub under yourHand WashingHand Washing Germ Fighting 101 Hand washing may be a simple task, but it is extremely important in preventing the spread of contagious illnesses. Wash your hands often to remove disease

  6. 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...

  7. Hand WashingHand Washing Germ Fighting 101

    E-print Network

    important in preventing the spread of contagious illnesses in child-care settings. Wash your hands often to remove disease-causing germs. Wash your hands upon arrival to the child-care setting in addition to: Wet of the Texas A&M AgriLife Extension Service are open to all people without regard to race, color, sex, religion

  8. 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…

  9. 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...

  10. Distributed Optimization and Control Using Only a Germ of Intelligence

    E-print Network

    Distributed Optimization and Control Using Only a Germ of Intelligence Kevin M. Passino Dept UNIVERSITY Outline · Foraging theory · Chemotactic behavior (foraging strategy) of E. coli · Bacterial UNIVERSITY Foraging Theory · Animals search for and obtain nutrients to maximize E T where E is energy

  11. 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...

  12. 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

  13. 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

  14. 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...

  15. 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

  16. Prognostic factors in children with extracranial germ cell tumors treated with cisplatin-based chemotherapy

    PubMed Central

    Kim, Jinsup; Lee, Na Hee; Yoo, Keon Hee; Sung, Ki Woong; Koo, Hong Hoe; Seo, Jeong-Meen; Lee, Suk-Koo

    2015-01-01

    Purpose To evaluate the outcomes and prognostic factors in children with extracranial germ cell tumors (GCTs) treated at a single institution. Methods Sixty-six children diagnosed with extracranial GCTs between 1996 and 2012 were included in the study. Primary treatment was surgical excision, followed by six cycles of cisplatin-based chemotherapy. The survival rates were compared according to the International Germ Cell Cancer Cooperative Group classification used for GCTs in adults to validate the classification guidelines for GCTs in children. Results The median patient age was 4.4 years. In 34 patients (51.5%), the primary tumor site was the gonad. Extragonadal GCTs were detected in 32 patients. The 5-year overall survival and event-free survival (EFS) were 92.0%±3.5% and 90.4%±3.7%, respectively. In univariate analysis, tumor histology, metastasis, and elevated alpha-fetoprotein were not prognostic factors in children with extracranial GCTs. However, EFS was poorer in patients with mediastinal disease (n=12, 66.7%±13.6 %) than in those with nonmediastinal disease (n=54, 96.0%±2.8%) (P=0.001). The 5-year EFS was lower in patients older than 10 years, (n=21, 80.0%±8.9%) compared with those younger than 10 years (n=45, 95.2%±3.3%) (P=0.04). Multivariate analysis identified the mediastinal tumor site as the only independent prognostic factor. Conclusion The prognosis of children with extracranial GCTs was favorable. However, nongerminomatous mediastinal tumors were associated with poor survival in children. Further research is needed to improve the prognosis of children with malignant mediastinal GCTs. PMID:26576183

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

    PubMed

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

    2015-08-01

    A 20-year-old male presented with persistent right testicular pain. Following ultrasound detection of testicular nodules and biopsy for intraoperative consultation which yielded germ cell tumour, he underwent radical orchidectomy. A predominantly whitish cyst and a lobulated, variegated nodule were identified. Histology showed a mature cystic teratoma with a focus of infiltrative epithelioid cells containing eosinophilic cytoplasm and pleomorphic nuclei, invading ectatic vessel wall associated with fibrinoid change. These cells were positive for cytokeratin, human placental lactogen and inhibin, while negative for Melan-A, p63 and alpha-fetoprotein, consistent with placental site trophoblastic tumor (PSTT). The variegated nodule was a mixed germ cell tumour composed of embryonal carcinoma and immature teratoma. Aside from choriocarcinoma, primary trophoblastic tumors such as PSTT, which are derived from intermediate trophoblasts, are extremely rare in the testis. Aside from a case of pure testicular PSTT, 2 other cases have been described in association with germ cell tumour, of which one is a mature teratoma with PSTT that demonstrated gain of chromosome 12p. The other presented with PSTT in retroperitoneal recurrence of a testicular mixed germ cell tumour. We discussed the features of this tumour in the testis and important differentials in its diagnosis. PMID:26277672

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

    E-print Network

    distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud NIN mesoscale heterogeneity in radar reflectivity that is observed. 1. Introduction Observations indicateA FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate

  19. The purification, composition and specificity of wheat-germ agglutinin

    PubMed Central

    Allen, A. K.; Neuberger, A.; Sharon, N.

    1973-01-01

    1. The purification of wheat-germ agglutinin from commercial wheat germ is described. By ion-exchange chromatography three active proteins (isolectins) were separated, one of which was examined in detail. 2. The amino acid composition is unusual, as 20% of residues are half-cystine and 21% are glycine. Unlike most lectins and contrary to previous reports, this protein is not a glycoprotein. 3. The efficiency of various saccharides as inhibitors of the agglutination reaction was investigated and from this the specificity of the binding site was inferred. Of monosaccharides, only derivatives of glucose with a 2-acetamido group and a free 3-hydroxyl group are effective inhibitors, and glycosides of either anomeric configuration are bound. Oligosaccharides are much more powerful inhibitors of agglutination than are monosaccharides. 4. It is proposed that the binding site consists of three or four subsites with differing specificities, in a cleft in the molecule resembling that proposed for hen's-egg-white lysozyme. PMID:4737292

  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 Central

    Bale, Tracy L.

    2014-01-01

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

  3. Homotopy Type of Disentanglements of Multi-germs

    E-print Network

    Houston, Kevin

    of Leeds Leeds, LS2 9JT, U.K. e-mail: k.houston@leeds.ac.uk http://www.maths.leeds.ac.uk/khouston/ July 2330 1 Introduction For a complex analytic map-germ f : (Cn , S) (Cp , 0) where S is a finite set of points and where the origin in (Cp , 0) has an isolated instability we can find a nearby stable map which

  4. 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

  5. Sex-lethal, master and slave: a hierarchy of germ-line sex determination in Drosophila.

    PubMed

    Oliver, B; Kim, Y J; Baker, B S

    1993-11-01

    Female sex determination in the germ line of Drosophila melanogaster is regulated by genes functioning in the soma as well as genes that function within the germ line. Genes known or suspected to be involved in germ-line sex determination in Drosophila melanogaster have been examined to determine if they are required upstream or downstream of Sex-lethal+, a known germ-line sex determination gene. Seven genes required for female-specific splicing of germ-line Sex-lethal+ pre-mRNA are identified. These results together with information about the tissues in which these genes function and whether they control sex determination and viability or just sex determination in the germ line have been used to deduce the genetic hierarchy regulating female germ-line sex determination. This hierarchy includes the somatic sex determination genes transformer+, transformer-2+ and doublesex+ (and by inference Sex-lethal+), which control a somatic signal required for female germ-line sex determination, and the germ-line ovarian tumor genes fused+, ovarian tumor+, ovo+, sans fille+, and Sex-lethal+, which are involved in either the reception or interpretation of this somatic sex determination signal. The fused+, ovarian tumor+, ovo+ and sans fille+ genes function upstream of Sex-lethal+ in the germ line. PMID:8187645

  6. 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

  7. 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

  8. 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

  9. PGC-Enriched miRNAs Control Germ Cell Development.

    PubMed

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

    2015-10-31

    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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Systems of germs and theorems of zeros in infinite-dimensional spaces

    E-print Network

    Dorota Mozyrska; Zbigniew Bartosiewicz

    2006-12-13

    Systems of germs of sets in infinite-dimensional spaces are introduced and studied. Such a system corresponds to a local zero-set of an ideal of the ring of analytic functions of infinite number of variables. Conversely, this system of germs defines the ideal of germs of analytic functions vanishing on it. A theorem of zeros is proved, stating that this ideal is the radical (in the complex case) or real radical (in the real case) of the initial ideal.

  16. 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.

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

    PubMed

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

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

  18. The effect of inanition upon the development of the gonads and germ cells of larval frogs

    E-print Network

    Swingle, W W (Wilbur Willis), 1891-1975

    1916-01-01

    OF INANITION UPON THE DEVELOPMENT OF THE GONADS AND GERM CELLS OF LARVAL FROGS. • ' ' I 4 : \\ J W* W. Swingle A.B. Kansas University, 1915. A thesis submitted to the Department of Zoology and the Faculty of the Graduate School in partial fulfillment... , was carried to completion. The problem, stated briefly, was to determine the effect of prolonged starvation upon the development of the germ gland an läge, and germ cells of frog., larvae. The view is now current among biologists, that the germ cells...

  19. Contribution of donor and host mesenchyme to the transplanted tooth germs.

    PubMed

    Nakaki, T; Saito, K; Ida-Yonemochi, H; Nakagawa, E; Kenmotsu, S; Ohshima, H

    2015-01-01

    Autologous tooth germ transplantation of immature teeth is an alternative method of tooth replacement that could be used instead of dental implants in younger patients. However, it is paramount that the dental pulp remain vital and that root formation continue in the transplanted location. The goal of this study is to characterize the healing of allogenic tooth grafts in an animal model using GFP-labeled donor or host postnatal mice. In addition, the putative stem cells were labeled before transplantation with a pulse-chase paradigm. Transplanted molars formed cusps and roots and erupted into occlusion by 2 wk postoperatively. Host label-retaining cells (LRCs) were maintained in the center of pulp tissue associating with blood vessels. Dual labeling showed that a proportion of LRCs were incorporated into the odontoblast layer. Host cells, including putative dendritic cells and the endothelium, also immigrated into the pulp tissue but did not contribute to the odontoblast layer. Therefore, LRCs or putative mesenchymal stem cells are retained in the transplanted pulps. Hertwig's epithelial root sheath remains vital, and epithelial LRCs are present in the donor cervical loops. Thus, the dynamic donor-host interaction occurred in the developing transplant, suggesting that these changes affect the characteristics of the dental pulp. PMID:25376722

  20. 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.

  1. 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

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

    PubMed

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

    2014-12-01

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

  3. Simultaneous linearization of holomorphic germs in presence of resonances

    NASA Astrophysics Data System (ADS)

    Raissy, Jasmin

    Let f_{1}, ..., f_{m} be m? 2 germs of biholomorphisms of C^{n} , fixing the origin, with (df_{1})_{O} diagonalizable and such that f_{1} commutes with f_{h} for any h=2,..., m . We prove that, under certain arithmetic conditions on the eigenvalues of (df_{1})_{O} and some restrictions on their resonances, f_{1}, ..., f_{m} are simultaneously holomorphically linearizable if and only if there exists a particular complex manifold invariant under f_{1}, ..., f_{m} .

  4. Vinblastine, actinomycin D, bleomycin, cyclophosphamide and cis-platinum for advanced germ cell testis tumors: Brazilian experience.

    PubMed

    Srougi, M; Simon, S D; de Góes, G M

    1985-07-01

    Disseminated germ cell testicular cancer proved to be highly sensitive to platinum-containing chemotherapy regimens. We present data concerning the treatment of advanced seminoma and nonseminomatous tumors in a developing country. We treated 30 patients with advanced germ cell testis tumors with 3 or 4 cycles of vinblastine, actinomycin D, bleomycin, cyclophosphamide and cis-platinum. Surgical resection of residual masses was done 30 days after completion of chemotherapy in 18 patients. The histology of the primary tumor was seminoma in 13 patients and nonseminomatous tumors in 17. Toxicity was mild and no treatment-related deaths occurred. All 13 patients (100 per cent) with seminoma and 12 of 17 patients (71 per cent) with nonseminomatous tumors had a complete response to chemotherapy, and 1 of 17 patients was free of disease after a debulking operation and additional chemotherapy. A total of 3 patients with seminoma and 2 with nonseminomatous tumors had recurrences 5 to 8 months after an initial complete response and received additional chemotherapy (VP-16 regimen) with or without radiotherapy. Complete clinical response was achieved in 4 of 5 patients. Median followup was 24 months (range 8 to 38 months) in the 13 patients with seminoma and 28 months (range 9 to 58 months) in those with nonseminomatous tumors, and 13 (100 per cent) and 12 (71 per cent), respectively, are alive without evidence of disease. These data suggest that the protocol of vinblastine, actinomycin D, bleomycin, cyclophosphamide and cis-platinum is highly effective and minimally toxic in the treatment of disseminated germ cell testicular cancer, inducing an 83 per cent long-lasting clinical remission. Seminomas seem to be equally or even more sensitive than nonseminomatous tumors to this platinum-containing chemotherapy regimen. Recurrence after initial complete response can be treated successfully with regimens containing VP-16. PMID:2409300

  5. Development and evolution of the vertebrate primary mouth.

    PubMed

    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

  6. Development and evolution of the vertebrate primary mouth

    PubMed Central

    Soukup, Vladimír; Horácek, Ivan; Cerny, Robert

    2013-01-01

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

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

    PubMed

    Sawada, Takashi

    2015-12-01

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

  8. Reconstructing the ancestral germ line methylation state of young repeats.

    PubMed

    Feuerbach, Lars; Lyngsø, Rune B; Lengauer, Thomas; Hein, Jotun

    2011-06-01

    One of the key objectives of comparative genomics is the characterization of the forces that shape genomes over the course of evolution. In the last decades, evidence has been accumulated that for vertebrate genomes also epigenetic modifications have to be considered in this context. Especially, the elevated mutation frequency of 5-methylcytosine (5mC) is assumed to facilitate the depletion of CpG dinucleotides in species that exhibit global DNA methylation. For instance, the underrepresentation of CpG dinucleotides in many mammalian genomes is attributed to this effect, which is only neutralized in so-called CpG islands (CGIs) that are preferentially unmethylated and thus partially protected from rapid CpG decay. For primate-specific CpG-rich transposable elements from the ALU family, it is unclear whether their elevated CpG frequency is caused by their small age or by the absence of DNA methylation. In consequence, these elements are often misclassified in CGI annotations. We present a method for the estimation of germ line methylation from pairwise ancestral-descendant alignments. The approach is validated in a simulation study and tested on DNA repeats from the AluSx family. We conclude that a predicted unmethylated state in the germ line is highly correlated with epigenetic activity of the respective genomic region. Thus, CpG-rich repeats can be facilitated as in silico probes for the epigenetic potential of their genomic neighborhood. PMID:21212152

  9. 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

  10. Chromatin dynamics during epigenetic reprogramming in the mouse germ line.

    PubMed

    Hajkova, Petra; Ancelin, Katia; Waldmann, Tanja; Lacoste, Nicolas; Lange, Ulrike C; Cesari, Francesca; Lee, Caroline; Almouzni, Genevieve; Schneider, Robert; Surani, M Azim

    2008-04-17

    A unique feature of the germ cell lineage is the generation of totipotency. A critical event in this context is DNA demethylation and the erasure of parental imprints in mouse primordial germ cells (PGCs) on embryonic day 11.5 (E11.5) after they enter into the developing gonads. Little is yet known about the mechanism involved, except that it is apparently an active process. We have examined the associated changes in the chromatin to gain further insights into this reprogramming event. Here we show that the chromatin changes occur in two steps. The first changes in nascent PGCs at E8.5 establish a distinctive chromatin signature that is reminiscent of pluripotency. Next, when PGCs are residing in the gonads, major changes occur in nuclear architecture accompanied by an extensive erasure of several histone modifications and exchange of histone variants. Furthermore, the histone chaperones HIRA and NAP-1 (NAP111), which are implicated in histone exchange, accumulate in PGC nuclei undergoing reprogramming. We therefore suggest that the mechanism of histone replacement is critical for these chromatin rearrangements to occur. The marked chromatin changes are intimately linked with genome-wide DNA demethylation. On the basis of the timing of the observed events, we propose that if DNA demethylation entails a DNA repair-based mechanism, the evident histone replacement would represent a repair-induced response event rather than being a prerequisite. PMID:18354397

  11. 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

  12. 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).

  13. AntiInflammatory Properties of Wheat Germ Oil (WGO) Formulations Developed at Oklahoma State University

    E-print Network

    AntiInflammatory Properties of Wheat Germ Oil (WGO) Formulations Developed at Oklahoma State health benefits is wheat and its by products. Oklahoma is one of the largest wheat growing states in the country. In this project, we will study the antiinflammatory effects of wheat germ oil (WGO) which has

  14. 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...

  15. 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…

  16. Z .Chemical Geology 145 1998 153159 z /Geochemical Earth Reference Model GERM

    E-print Network

    Langmuir, Charles H.

    Z .Chemical Geology 145 1998 153­159 z /Geochemical Earth Reference Model GERM : description on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. The Z .GERM chemical Z . Z .reservoirs of the present-day Earth, from core to atmosphere; 2 present-day fluxes between

  17. ON THE GALOIS REDUCIBILITY OF A GERM OF QUASI-HOMOGENEOUS FOLIATION

    E-print Network

    ON THE GALOIS REDUCIBILITY OF A GERM OF QUASI-HOMOGENEOUS FOLIATION E. PAUL 1. Introduction From recent developments in non linear differential Galois theory, we have now three equivalent definitions for the Galois reducibility of a codimension one foliation defined by a germ of holomorphic one

  18. 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...

  19. 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

  20. 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....

  1. INTRODUCTION The primordial germ cells in Xenopus are thought to be

    E-print Network

    components. Ultrastructurally, germ plasm appears as an electron-dense cytoplasmic aggregation of RNP). Embryological experiments support a role for germ plasm in PGC specification. Removal of vegetal pole egg cytoplasm (Buehr and Blackler, 1970), treatment of eggs with low doses of ultraviolet (u.v.) light (Züst

  2. Origin and Development of the Germ Line in Sea Stars Gary M. Wessel,1

    E-print Network

    Wessel, Gary M.

    that are barbed (e.g., the crown of thorns sea star, of the Acanthaster genus), and arms of a myriad of colors. Key words: sea star; starfish; posterior enterocoel; germ line; primordial germ cell INTRODUCTION Sea://spongebob.nick.com/ The terms sea stars and starfish refer to the same group of organisms. Since starfish are not actual fish

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

    EPA Science Inventory

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

  4. Primary Syphilis

    MedlinePLUS

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

  5. Syphilis - primary

    MedlinePLUS

    Primary syphilis; Secondary syphilis; Late syphilis; Tertiary syphilis ... Syphilis has three stages: Primary syphilis Secondary syphilis Tertiary syphilis (the late phase of the illness) Secondary ...

  6. 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

  7. 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

  8. 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

  9. Influence of wheat germ and ?-glucan on some chemical and sensory properties of Turkish noodle.

    PubMed

    Akta?, Kübra; Bilgiçli, Nermin; Levent, Hacer

    2015-09-01

    Wheat flour used in Turkish noodle (eri?te) production was replaced with wheat germ (0, 10, 20 and 30 %) and ?-glucan (0 and 4 %). Noodle samples were analyzed for their moisture, ash, protein, fat, mineral contents, color values and sensory properties. Cooking properties as volume increase (VI), weight increase (WI) and cooking loss (CL) were also determined. Wheat germ increased the ash, protein, fat and mineral contents of the noodles. ?-glucan had an improving effect especially on Ca, Fe, Mg and P contents of noodle samples. While wheat germ raised VI values of the noodle, ?-glucan had a negative effect on VI. The CL of noodle samples varied between 5.8 % and 7.3 %. Decreasing sensory scores obtained at high level of wheat germ with and without ?-glucan. The present results showed that wheat germ and ?-glucan have a good potential for increasing nutritional quality of noodle. PMID:26345028

  10. Hyperpolarization-activated, cyclic AMP-gated, HCN1-like cation channel: the primary, full-length HCN isoform expressed in a saccular hair-cell layer.

    PubMed

    Cho, W J; Drescher, M J; Hatfield, J S; Bessert, D A; Skoff, R P; Drescher, D G

    2003-01-01

    The expression of transcript for hyperpolarization-activated, cyclic nucleotide-sensitive cation channel (HCN) isoforms underlying hyperpolarization-activated, inward current (I(h)) has been determined for a model hair-cell preparation from the saccule of the rainbow trout, Oncorhynchus mykiss. Based upon identification from homology to known vertebrate HCN cDNA sequence, cloning of PCR products amplified with degenerate primers indicated an expression frequency of 7:2:1 (HCN1:HCN2:HCN4) for the hair-cell sheet compared with 1:1:7 for brain. Full-length sequence has been obtained for the HCN1-like isoform representing the primary HCN transcript expressed in the hair-cell preparation. The channel protein is 938 amino acids in length with 93% amino acid identity for the region extending from the S1-S6 membrane spanning domains through the voltage-pore and cyclic nucleotide-binding domains, compared with HCN1 for rabbit, rat, mouse and human. The N- and C-terminal regions are less homologous, with 39-51% and 43-44% amino acid identities, respectively. Compared with other vertebrate HCN1, the hair-cell HCN1 contains additional consensus phosphorylation sites associated with unique repeats in the carboxy terminus. The HCN1-like transcript has been localized to hair cells of the saccular sensory epithelia by in situ hybridization. Previous electrophysiological studies have identified I(h) as the sole inwardly rectifying ion channel in a specific population of hair cells of the saccule of frogs [J Neurophysiol (1995) 73:1484] and fish [J Physiol (1996) 495:665]. I(h) is an important determinant of the resting membrane potential, and for this population of hair cells, is predicted to maintain the membrane potential within a voltage range allowing the voltage-gated calcium channels to open, permitting "spontaneous" release of transmitter. The molecular properties of the HCN1-like isoform underlying I(h) expressed in the saccular hair cells of the teleost, trout, may consequently impact spontaneous release of transmitter from hair cells of the saccule. PMID:12699787

  11. 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.

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

    PubMed Central

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

    2015-01-01

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

  13. 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 ...

  14. 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...

  15. 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-.

  16. Comprehensive DNA Methylation Analysis of Retrotransposons in Male Germ Cells.

    PubMed

    Nagamori, Ippei; Kobayashi, Hisato; Shiromoto, Yusuke; Nishimura, Toru; Kuramochi-Miyagawa, Satomi; Kono, Tomohiro; Nakano, Toru

    2015-09-01

    De novo DNA methylation of retrotransposons is critical for silencing. Here, we use DNA methylation analysis to examine retrotransposons in mouse male germ cells. DNA methylation of long interspersed nuclear elements (LINEs) is dependent on piRNA, and younger LINEs exhibit greater piRNA dependence. In contrast, most long terminal repeat (LTR) retrotransposons produce lower levels of piRNAs and do not show significant piRNA dependence. The relationship between DNA methylation and corresponding piRNA expression of several LTR retrotransposons was reduced in Mili-null cells, but not Miwi2-null cells. These observations raise the possibility of piRNA-dependent DNA methylation without Miwi2. Therefore, it appears that the molecular mechanisms of the gene silencing of retrotransposons are more complicated than previously thought. PMID:26321633

  17. The story of a largely unknown evolution – Germ theory hoax

    PubMed Central

    Wainwright, Milton; Alharbi, Sulaiman Ali

    2011-01-01

    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

  18. 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

  19. 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

  20. [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

  1. Testicular germ cell tumors. Current concepts and management strategies.

    PubMed

    Cost, N G

    2013-06-01

    Testicular germ cell tumors (T-GCTs) are the most common solid tumor in adolescent and young adult men. Due to the success of multidisciplinary management, the prognosis of all stages of T-GCT is quite good. The development of complimentary therapeutic strategies including modern cytotoxic chemotherapy regimens, appropriate utilization of radiotherapy, and timely surgical resection has made T-GCTs the model of a "curative" malignancy. Herein we review the background, epidemiology, and genetics of the disease, as well as an approach to its diagnosis and staging, including rationale for managing T-GCT in its various stages. In summary, while some areas in T-GCT care are debated, the vast majority of patients should be approached in a standardized manner which ensures optimal oncologic outcomes and minimal therapeutic morbidity. PMID:23703101

  2. [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

  3. 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

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

    PubMed

    Pacchiarini, Tiziana; Sarasquete, Carmen; Cabrita, Elsa

    2014-06-01

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

  5. 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

  6. 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

  7. 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.

  8. NUP50 is necessary for the survival of primordial germ cells in mouse embryos.

    PubMed

    Park, Eunsook; Lee, Bobae; Clurman, Bruce E; Lee, Keesook

    2016-01-01

    Nucleoporin 50?kDa (NUP50), a component of the nuclear pore complex, is highly expressed in male germ cells, but its role in germ cells is largely unknown. In this study, we analyzed the expression and function of NUP50 during the embryonic development of germ cells using NUP50-deficient mice. NUP50 was expressed in germ cells of both sexes at embryonic day 15.5 (E15.5), E13.5, and E12.5. In addition, NUP50 expression was also detected in primordial germ cells (PGCs) migrating into the genital ridges at E9.5. The gonads of Nup50-/- embryos of both sexes contained few PGCs at both E11.5 and E12.5 and no developing germ cells at E15.5. The migratory PGCs in Nup50-/- embryos at E9.5 showed increased apoptosis but a normal rate of proliferation, resulting in the progressive loss of germ cells at later stages. Taken together, these results suggest that NUP50 plays an essential role in the survival of PGCs during embryonic development. PMID:26515778

  9. 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

  10. 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

  11. 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

  12. Chemotherapy for Good-Risk Nonseminomatous Germ Cell Tumors: Current Concepts and Controversies.

    PubMed

    In, Gino; Dorff, Tanya

    2015-08-01

    The rate of diagnosis of germ cell tumors has remained fairly constant. By the International Germ Cell Cancer Consensus Classification, roughly 60% of all metastatic germ cell tumors are classified as good risk. This group of patients has an excellent prognosis, with greater than 90% expectation of cure. Treatment standards have not changed much in recent years. This article focuses on key concepts in the development of the currently accepted first-line regimens and addresses some evolving areas of interest, if not controversy. PMID:26216822

  13. "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

  14. Primary Aldosteronism

    MedlinePLUS

    ... MD, MSc What is primary aldosteronism? Primary aldosteronism (PA) is a type of hyperaldosteronism. This condition occurs ... stroke may be even greater in people with PA than in other people with high blood pressure. ...

  15. 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

  16. Regulation of ovarian function by the germ cell specific DAZL gene 

    E-print Network

    Brown, Yvonne A. R.

    2009-01-01

    The RNA binding protein DAZL (Deleted in Azoospermia) is essential for germ cell survival and subsequent fertility. The transgenic mouse DAZL model has confirmed that knockout (KO) females are infertile as a direct consequence of complete postnatal...

  17. Autophagy is a cell survival program for female germ cells in the murine ovary.

    PubMed

    Gawriluk, Thomas R; Hale, Amber N; Flaws, Jodi A; Dillon, Christopher P; Green, Douglas R; Rucker, Edmund B

    2011-06-01

    It is estimated that infertility affects 15-20% of couples and can arise from female or male reproductive defects. Mouse models have ascribed roles to over 100 genes in the maintenance of female fertility. Although previous models have determined roles for apoptosis in male and female fertility, we find that compromised autophagy within the perinatal ovary, through the loss of Becn1 or Atg7, results in the premature loss of female germ cells. Becn1(+/-) ovaries have a 56% reduction of germ cells compared with control ovaries at post-natal day 1, whereas Atg7(-/-) ovaries lack discernable germ cells at this stage. Thus autophagy appears to be a cell survival mechanism to maintain the endowment of female germ cells prior to establishing primordial follicle pools in the ovary. PMID:21464117

  18. 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

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

    E-print Network

    Clark, Alan B

    1998-01-01

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

  1. Effect of Monascus aged vinegar on isoflavone conversion in soy germ by soaking treatment.

    PubMed

    Chen, Ji-Cheng; Wang, Jie; Wang, Zhi-Jiang; Li, Yan-Jie; Pang, Jie; Lin, He-Tong; Yin, Shou-Wei

    2015-11-01

    Soy germ rich in isoflavones has attracted much attention for health-promoting characteristics. An effective approach via Monascus aged vinegar soaking was adopted to enhance the aglycone amount. The profiles and interconversion of soy germ isoflavones via Monascus aged vinegar soaking were investigated, and the distribution in vinegars were also explored. The aglycones were dramatically increased by 40.76 times. Concomitantly, ?-glycosides and malonylglycosides were significantly decreased. The proportion of aglycones presented a sharp increase with the endogenous ?-glucosidase activity at the initial 4h incubation. There appeared to be correlations between ?-glucosidase activity and the hydrolysis of conjugated isoflavones. The results demonstrated that the reactions of decarboxylation, de-esterification and de-glycosylation were involved in the Monascus aged vinegar soaking, supporting synergistic effects of enzymolysis by endogenous ?-glucosidase from soy germ and acid hydrolysis of vinegars. Soaking by vinegar is a promising pathway for preparing aglycone-rich soy germ. PMID:25976819

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

    E-print Network

    Garcia Lopez, Claudia Monica

    2009-01-01

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

  4. 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

  5. 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.

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

    E-print Network

    Hu, Yueh-Chiang

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate ...

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

    E-print Network

    Alwes, Frederike

    Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect Ben in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing

  8. The effects of growth factors on testicular germ cell apoptosis in the stallion 

    E-print Network

    Donnelly, Casey Leanne

    2002-01-01

    recombinant growth factors, stem cell factor (SCF), leukemia inhibiting factor (LIF), granulocyte macrophage-colony stimulating factor (GM-CSF), and one hormone, estradiol (E?), alone or in combination, to prevent apoptosis of germ cells in short-term equine...

  9. 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

  10. 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.

  11. 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.

  12. RNF17, a component of the mammalian germ cell nuage, is essential for spermiogenesis

    PubMed Central

    Pan, Jieyan; Goodheart, Mary; Chuma, Shinichiro; Nakatsuji, Norio; Page, David C.; Wang, P. Jeremy

    2007-01-01

    Summary Nuages are found in the germ cells of diverse organisms. However, nuages in postnatal male germ cells of mice are poorly studied. Previously, we cloned a germ cell-specific gene named Rnf17, which encodes a protein containing both a RING finger and tudor domains. Here, we report that RNF17 is a component of a novel nuage in male germ cells – the RNF17 granule, which is an electron-dense non-membrane bound spherical organelle with a diameter of 0.5 ?m. RNF17 granules are prominent in late pachytene and diplotene spermatocytes, and in elongating spermatids. RNF17 granules are distinguishable from other known nuages, such as chromatoid bodies. RNF17 is able to form dimers or polymers both in vitro and in vivo, indicating that it may play a role in the assembly of RNF17 granules. Rnf17-deficient male mice were sterile and exhibited a complete arrest in round spermatids, demonstrating that Rnf17 encodes a novel key regulator of spermiogenesis. Rnf17-null round spermatids advanced to step 4 but failed to produce sperm. These results have shown that RNF17 is a component of a novel germ cell nuage and is required for differentiation of male germ cells. PMID:16093322

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

    PubMed

    Nettersheim, Daniel; Biermann, Katharina; Gillis, Ad J M; Steger, Klaus; Looijenga, Leendert H J; Schorle, Hubert

    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 is 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

  14. Presence of third molar germs in orthodontic patients with class II/2 and class III malocclusions.

    PubMed

    Mady Marici?, Barbara; Legovi?, Mario; Slaj, Martina; Lapter Varga, Marina; Zuvi? Butorac, Marta; Kapovi?, Miljenko

    2009-12-01

    The aim of this study was to determine the presence of third molar germs in patients with Class II/2 and Class III malocclusions. The study comprised 146 examinees from Zagreb and Istria. Examinees with Class II/2 malocclusions amounted to 77 and those with Class III 69. With regard to development of dentition the examinees were divided into two groups: Group I subjects with early mixed dentition (23 subjects with Class II/2 and 21 subjects with Class III), and Group II subjects with late mixed dentition (54 subjects with Class II/2 and 48 subjects with Class III). Assessments were made from panoramic radiographs and lateral cephalograms. The Pearson chi2-test and Fisher's exact test was used to determine statistical significance in differences. Assessments showed that third molar germs were present significantly more often in the upper jaw in Class II/2 (58% vs. 44%) and in the lower jaw in Class III (83% vs. 69%). In subjects with Class II/2 all third molar germs were present statistically more often in late mixed dentition, which was also determined for maxillary third molar germs in Class III. The presence of mandibular third molar germs in Class III examinees was almost equal in both periods of mixed dentitions. The study confirmed correlation between the presence of third molar germs and sagital maxillomandibular relationship and encourages investigation of the differences in calcifications of all permanent teeth in such malocclusions. PMID:20102065

  15. 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

  16. 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

  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. 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

  19. Zebrafish vasa is required for germ-cell differentiation and maintenance

    PubMed Central

    Hartung, Odelya; Forbes, Meredyth M.; Marlow, Florence L.

    2014-01-01

    Vasa is a universal marker of the germ line in animals, yet mutations disrupting vasa cause sexually dimorphic infertility, with impaired development of the ovary in some animals and the testis in others. The basis for this sexually dimorphic requirement for Vasa is not clear; in most animals examined, both the male and female gonad express vasa throughout the life of the germ line. Here we characterized a loss-of-function mutation disrupting zebrafish vasa. We show that maternally provided Vasa is stable through the first ten days of development in zebrafish, and thus likely fulfill any early roles for Vasa during germ-line specification, migration, survival, and maintenance. Although zygotic Vasa is not essential for the development of juvenile gonads, vasa mutants develop exclusively as sterile males. Furthermore, phenotypes of vasa;p53 compound mutants are indistinguishable from those of vasa mutants, therefore the failure of vasa mutants to differentiate as females and to support germ-cell development in the testis is not due to p53-mediated apoptosis. Instead, we found that failure to progress beyond the pachytene stage of meiosis causes the loss of germ-line stem cells, leaving empty somatic tubules. Our studies provide insight into the function of zebrafish vasa during female meiosis, differentiation, and maintenance of germ-line stem cells. PMID:25257909

  20. Remarks on the Orbital Analytic Classification of Germs of Vector Fields

    NASA Astrophysics Data System (ADS)

    Elizarov, P. M.; Il'yashenko, Yu S.

    1984-02-01

    Associated to the germ of a holomorphic vector field on \\mathbf{C}^2 whose linear part belongs to a Siegel domain, is the germ of a conformal map (\\mathbf{C},\\,0)\\to(\\mathbf{C},\\,0); the latter is the monodromy transformation induced by a circuit around the singular point on a separatrix.It is proved that the monodromy transformations are moduli for the orbital analytic classification of germs of vector fields at a singular point: two vector field germs with the same linear part of Siegel type are orbitally analytically equivalent if and only if for each of the germs one can choose a local separatrix such that these separatrices are tangent at zero and such that the monodromy maps corresponding to them are analytically equivalent.Moduli for the orbital analytic classification of vector field germs in higher-dimensional spaces are also constructed, and a new proof of the theorem about the topological classification of vector fields with saddle resonant singular points is given.Bibliography: 24 titles.

  1. Responses of embryonic germ cells of the radiation-sensitive Medaka mutant to gamma-irradiation.

    PubMed

    Aizawa, Kouichi; Yori, Kanako; Kaminaga, Chiharu; Yamashita, Toshikazu; Kinoshita, Masato; Oda, Shoji; Mitani, Hiroshi

    2007-03-01

    The radiation-sensitive mutant "ric1" has a defect in the repair mechanism of DNA double strand breaks induced by gamma-rays in early embryogenesis. In this study, the new radiation-sensitive Medaka (Oryzias latipes) strain, ric1olvas-GFP was established to monitor the development of germ cells in vivo. The development of germ cells was normal in ric1olvas-GFP, but embryonic germ cells at Stage 7 (32-cell stage) and Stage 33 (extensive proliferating stage of PGCs) showed higher radiosensitivity. There was no sex difference in germ cell radiosensitivity at Stage 7, but female embryos showed higher radiosensitivity than male at Stage 33. In embryos obtained by crossing ric1 female with olvas-GFP male, germ cells showed similar radiosensitivity to ric1olvas-GFP and increased sensitivity compared to embryos obtained from crossing wild-type female with olvas-GFP male at Stage 7. These results suggest that germ cells have the ric1 dependent DNA repair system during embryogenesis and the maternal ric1gene factor may play a critical role in radiosensitivity at an early developmental stage. PMID:17339749

  2. 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.

  3. Morphometric Approach to Pulp Fibroblast Development in Tooth Germ

    PubMed Central

    C?runtu, Irina-Draga; S?vinescu, Sergiu Daniel; Am?linei, 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 4?A/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

  4. 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

  5. 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

  6. 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.

  7. Germ-line DICER1 mutations do not make a major contribution to the etiology of familial testicular germ cell tumours

    E-print Network

    Sabbaghian, Nelly; Bahubeshi, Amin; Shuen, Andrew Y.; Kanetsky, Peter A.; Tischkowitz, Marc D.; Nathanson, Katherine L.; Foulkes, William D.

    2013-04-01

    Abstract Background The RNase III enzyme DICER1 plays a central role in maturation of microRNAs. Identification of neoplasia-associated germ-line and somatic mutations in DICER1 indicates that mis-expression of miRNAs in cancer may result from...

  8. In vitro differentiation of human tooth germ stem cells into endothelial- and epithelial-like cells.

    PubMed

    Do?an, Ay?egül; Demirci, Selami; ?ahin, Fikrettin

    2015-01-01

    Current clinical techniques in dental practice include stem cell and tissue engineering applications. Dental stem cells are promising primary cell source for mainly tooth tissue engineering. Interaction of mesenchymal stem cell with epithelial and endothelial cells is strictly required for an intact tooth morphogenesis. Therefore, it is important to investigate whether human tooth germ stem cells (hTGSCs) derived from wisdom tooth are suitable for endothelial and epithelial cell transformation in dental tissue regeneration approaches. Differentiation into endothelial and epithelial cell lineages were mimicked under defined conditions, confirmed by real time PCR, western blotting and immunocytochemical analysis by qualitative and quantitative methods. HUVECs and HaCaT cells were used as positive controls for the endothelial and epithelial differentiation assays, respectively. Immunocytochemical and western blotting analysis revealed that terminally differentiated cells expressed cell-lineage markers including CD31, VEGFR2, VE-Cadherin, vWF (endothelial cell markers), and cytokeratin (CK)-17, CK-19, EpCaM, vimentin (epithelial cell markers) in significant levels with respect to undifferentiated control cells. Moreover, high expression levels of VEGFR1, VEGFR2, VEGF, CK-18, and CK-19 genes were detected in differentiated endothelial and epithelial-like cells. Endothelial-like cells derived from hTGSCs were cultured on Matrigel, tube-like structure formations were followed as an indication for functional endothelial differentiation. hTGSCs successfully differentiate into various cell types with a broad range of functional abilities using an in vitro approach. These findings suggest that hTGSCs may serve a potential stem cell source for tissue engineering and cell therapy of epithelial and endothelial tissue. PMID:25077982

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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 ?g/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 ?M Fe2+ treatment, but the accumulation was strongly inhibited by 100 ?g/mL of WGE and F-WGE treatment. These results suggest that changes in bioactive substances during the fermentation of wheat germ can potentiate scavenging activities against transition metal-induced oxidative stress and lipid accumulation in 3T3-L1 adipocytes. Therefore, we propose that F-WGE is a novel food materials and provided scientific evidences for its efficacy in the development of functional foods. PMID:25866747

  15. Endogenous DNA Damage and Risk of Testicular Germ Cell Tumors

    SciTech Connect

    Cook, M B; Sigurdson, A J; Jones, I M; Thomas, C B; Graubard, B I; Korde, L; Greene, M H; McGlynn, K A

    2008-01-18

    Testicular germ cell tumors (TGCT) are comprised of two histologic groups, seminomas and nonseminomas. We postulated that the possible divergent pathogeneses of these histologies may be partially explained by variable endogenous DNA damage. To assess our hypothesis, we conducted a case-case analysis of seminomas and nonseminomas using the alkaline comet assay to quantify single-strand DNA breaks and alkali-labile sites. The Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort provided 112 TGCT cases (51 seminomas & 61 nonseminomas). A lymphoblastoid cell line was cultured for each patient and the alkaline comet assay was used to determine four parameters: tail DNA, tail length, comet distributed moment (CDM) and Olive tail moment (OTM). Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. Values for tail length, tail DNA, CDM and OTM were modeled as categorical variables using the 50th and 75th percentiles of the seminoma group. Tail DNA was significantly associated with nonseminoma compared to seminoma (OR{sub 50th percentile} = 3.31, 95%CI: 1.00, 10.98; OR{sub 75th percentile} = 3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR{sub 50th percentile} = 2.27, 95%CI: 0.75, 6.87; OR{sub 75th percentile} = 2.40, 95%CI: 0.75, 7.71; p for trend=0.12) whereas tail length and CDM showed no association. In conclusion, the results for tail DNA and OTM indicate that endogenous DNA damage levels are higher in patients who develop nonseminoma compared with seminoma. This may partly explain the more aggressive biology and younger age-of-onset of this histologic subgroup compared with the relatively less aggressive, later-onset seminoma.

  16. 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

  17. Wheat germ agglutinin is selectively transported to multivesicular bodies.

    PubMed

    Becich, M J; Mahklouf, S; Baenziger, J U

    1991-06-01

    Colloidal iron dextran particles bearing wheat germ agglutinin (WGA/FeDex) were bound by glycoconjugates expressed at the surface of HepG2 cells. Bound WGA/FeDex was internalized when cells were incubated at 37 degrees C and accumulated in intracellular structures which have the same buoyant density as the plasma membrane when examined on Percoll density gradients. The intracellular structures containing WGA/FeDex were identified as multivesicular bodies (MVB) by transmission electron microscopy. WGA/FeDex was not transported to lysosomes nor did it interfere with uptake and transport of GalBSA to lysosomes by the asialoglycoprotein receptor. WGA/FeDex was seen predominantly in non-coated invaginations at the cell surface, suggesting it may enter cells at a different site than GalBSA/FeDex. Highly enriched plasma membranes and MVBs containing superparamagnetic [125I]WGA/FeDex particles were prepared by high gradient magnetic affinity chromatography (HIMAC). Plasma membranes prepared by HIMAC were enriched 30-fold for [125I]WGA/FeDex, 15-fold for alkaline phosphodiesterase I, and 9-fold for galactosyltransferase relative to the crude post-nuclear homogenate and consisted entirely of plasmalemmal sheets. Intracellular structures containing WGA/FeDex were enriched 35-fold for [125I]WGA/FeDex, 10-fold for alkaline phosphodiesterase I, and 10-fold for galactosyltransferase but did not contain lysosomal beta-galactosidase. WGA/FeDex has a different ultimate destination in HepG2 cells than ligands internalized by the asialoglycoprotein receptor and can be used to obtain highly enriched plasma membranes and MVBs from cultured cells. PMID:1680682

  18. 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

  19. 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

  20. 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

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

    MedlinePLUS

    ... Tweet Share Compartir Salmonella can contaminate more than poultry and eggs. It sneaks its way into many ... of foods, not just from eggs and undercooked poultry. Although poultry and eggs are primary culprits, Salmonella ...

  2. 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.

  3. 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

  4. 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

  5. Essential role of Sox2 for the establishment and maintenance of the germ cell line.

    PubMed

    Campolo, Federica; Gori, Manuele; Favaro, Rebecca; Nicolis, Silvia; Pellegrini, Manuela; Botti, Flavia; Rossi, Pellegrino; Jannini, Emmanuele A; Dolci, Susanna

    2013-07-01

    Sox2 is a pluripotency-conferring gene expressed in primordial germ cells (PGCs) and postnatal oocytes, but the role it plays during germ cell development and early embryogenesis is unknown. Since Sox2 ablation causes early embryonic lethality shortly after blastocyst implantation, we generated mice bearing Sox2-conditional deletion in germ cells at different stages of their development through the Cre/loxP recombination system. Embryos lacking Sox2 in PGCs show a dramatic decrease of germ cell numbers at the time of their specification. At later stages, we found that Sox2 is strictly required for PGC proliferation. On the contrary, Sox2 deletion in meiotic oocytes does not impair postnatal oogenesis and early embryogenesis, indicating that it is not essential for oocyte maturation or for zygotic development. We also show that Sox2 regulates Kit expression in PGCs and binds to discrete transcriptional regulatory sequences of this gene, which is known to be important for PGCs survival and proliferation. Sox2 also stimulates the expression of Zfp148, which is required for normal development of fetal germ cells, and Rif1, a potential regulator of PGC pluripotency. PMID:23553930

  6. 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

  7. The epigenetics of germ-line immortality: lessons from an elegant model system.

    PubMed

    Furuhashi, Hirofumi; Kelly, William G

    2010-08-01

    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

  8. 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

  9. [Primary hyperparathyroidism].

    PubMed

    Maruani, G; Cornière, N; Nicolet, L; Baron, S; Courbebaisse, M; Renaud, S; Houillier, P

    2013-10-01

    For the past 40 years, primary hyperparathyroidism has been recognized as a common endocrine disease which is, most often, "non-symptomatic", without the occurrence of nephrolithiasis or osteitis fibrosa cystica. Our knowledge in the pathophysiology has increased largely and diagnosis of primary hyperparathyroidism is usually easy. The only radical treatment is surgery and the surgical indications have been codified by several consensus conferences. For patients who do not undergo surgery, prolonged medical monitoring is needed. PMID:23195909

  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. 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. 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

  14. Inhibitory Phosphorylation of Separase Is Essential for Genome Stability and Viability of Murine Embryonic Germ Cells

    PubMed Central

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

    2008-01-01

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

  15. 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

  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. 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.

  18. 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.

  19. Genome-wide erasure of DNA methylation in mouse primordial germ cells is affected by AID deficiency

    E-print Network

    Jacobsen, Steve

    in the germ line is a global process, hence limiting the potential for transgenera- tional epigeneticLETTERS Genome-wide erasure of DNA methylation in mouse primordial germ cells is affected by AID Pellegrini2 , Steven E. Jacobsen2,4 & Wolf Reik1 Epigenetic reprogramming including demethylation of DNA

  20. 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

  1. 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...

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

    E-print Network

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

    2005-01-01

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

  3. A set of genes critical to development is epigenetically poised in mouse germ cells from fetal stages through completion of meiosis

    E-print Network

    Lesch, Bluma J.

    In multicellular organisms, germ cells carry the hereditary material from one generation to the next. Developing germ cells are unipotent gamete precursors, and mature gametes are highly differentiated, specialized cells. ...

  4. 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.

  5. 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

  6. Mixed Germ Cell Tumor of Testis with Isolated Scapular Metastasis: A Case Report and Review of the Literature.

    PubMed

    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

  7. 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

  8. Primary Hyperparathyroidism

    MedlinePLUS

    ... in osteoporosis (weak bones that break easily), kidney stones (small clumps of calcium), and a decline in kidney function. DiD YOu knOW? Women are more likely than men to develop primary hyperparathyroidism, and the risk increases with age. FAcT SHeeT Parathyroid Glands thyroid Gland Back View ...

  9. Primary Hyperparathyroidism

    MedlinePLUS

    ... D.C.: American Society of Bone and Mineral Research; 2009: 361–367. Eastell R, Arnold A, Brandi ML, et al. Diagnosis of asymptomatic primary hyperparathyroidism: proceedings of the Third International Workshop. Journal of Clinical Endocrinology and Metabolism. 2009;94(2): ...

  10. 373T. Schedl (ed.), Germ Cell Development in C. elegans, Advances in Experimental Medicine and Biology 757, DOI 10.1007/978-1-4614-4015-4_13,

    E-print Network

    to degeneration of the germ line and/or an inability to produce functional gametes. Keywords Epigenetic · C the development of the C. elegans germ line. Histone modifications are differentially regulated in the mitotic vs meiotic germ line, on X chromosomes vs autosomes and on paired chromosomes vs unpaired chromosomes. Small

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

    E-print Network

    Kirschner, Marc W.

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

  12. 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...

  13. 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...

  14. 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

  15. Primary perisplenic hydatid cyst.

    PubMed

    Sharif, Muhammad Ashraf; Mahmood, Asad; Murtaza, Badar; Malik, Imran Bashir; Khan, Abdullah; Asghar, Zunera; Arif, Adeel

    2009-06-01

    Splenic parasitic cysts due to flat worm Echinococci resulting in hydatid disease are a rare presentation as primary site even in the endemic regions. Primary splenic parasitic cysts have an incidence of 0.5-4%. A 21-year-old male with pet dogs at home, presented with 3 months history of gradually increasing discomfort in the left hypochondrium and tender splenomegaly. He had marked eosinophilia with normal liver function tests and positive serum IgM Echinococcus antibodies. Ultrasonography showed a cyst in the hilar region of spleen having septations with internal echos. An upper midline laparotomy was performed and a perisplenic cyst was removed along with spleen from the sub-diaphragmatic location. Histopathological examination confirmed acellular fibrous wall of hydatid cyst with germinal layer and scolices in the centre. Postoperatively, patient was continued on oral Albendazole for one month. PMID:19486579

  16. In vitro derivation of mammalian germ cells from stem cells and their potential therapeutic application.

    PubMed

    Saito, Shigeo; Lin, Ying-Chu; Murayama, Yoshinobu; Nakamura, Yukio; Eckner, Richard; Niemann, Heiner; Yokoyama, Kazunari K

    2015-12-01

    Pluripotent stem cells (PSCs) are a unique type of cells because they exhibit the characteristics of self-renewal and pluripotency. PSCs may be induced to differentiate into any cell type, even male and female germ cells, suggesting their potential as novel cell-based therapeutic treatment for infertility problems. Spermatogenesis is an intricate biological process that starts from self-renewal of spermatogonial stem cells (SSCs) and leads to differentiated haploid spermatozoa. Errors at any stage in spermatogenesis may result in male infertility. During the past decade, much progress has been made in the derivation of male germ cells from various types of progenitor stem cells. Currently, there are two main approaches for the derivation of functional germ cells from PSCs, either the induction of in vitro differentiation to produce haploid cell products, or combination of in vitro differentiation and in vivo transplantation. The production of mature and fertile spermatozoa from stem cells might provide an unlimited source of autologous gametes for treatment of male infertility. Here, we discuss the current state of the art regarding the differentiation potential of SSCs, embryonic stem cells, and induced pluripotent stem cells to produce functional male germ cells. We also discuss the possible use of livestock-derived PSCs as a novel option for animal reproduction and infertility treatment. PMID:26439925

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

    E-print Network

    Carpenter, Anne E.

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

  18. Premeiotic germ cell defect in seminiferous tubules of Atm-null testis

    SciTech Connect

    Takubo, Keiyo . E-mail: keiyot@gmail.com; Hirao, Atsushi; Ohmura, Masako; Azuma, Masaki; Arai, Fumio; Nagamatsu, Go; Suda, Toshio . E-mail: sudato@sc.itc.keio.ac.jp

    2006-12-29

    Lifelong spermatogenesis is maintained by coordinated sequential processes including self-renewal of stem cells, proliferation of spermatogonial cells, meiotic division, and spermiogenesis. It has been shown that ataxia telangiectasia-mutated (ATM) is required for meiotic division of the seminiferous tubules. Here, we show that, in addition to its role in meiosis, ATM has a pivotal role in premeiotic germ cell maintenance. ATM is activated in premeiotic spermatogonial cells and the Atm-null testis shows progressive degeneration. In Atm-null testicular cells, differing from bone marrow cells of Atm-null mice, reactive oxygen species-mediated p16{sup Ink4a} activation does not occur in Atm-null premeiotic germ cells, which suggests the involvement of different signaling pathways from bone marrow defects. Although Atm-null bone marrow undergoes p16{sup Ink4a}-mediated cellular senescence program, Atm-null premeiotic germ cells exhibited cell cycle arrest and apoptotic elimination of premeiotic germ cells, which is different from p16{sup Ink4a}-mediated senescence.

  19. [Intrathoracic lesions in association with germ cell tumor of the testis].

    PubMed

    Mann, O; Kleinhans, H; Gebauer, F; Kaifi, J; Schurr, P G; Izbicki, J R; Strate, T G

    2008-09-01

    Intrathoracic enlarged lymph nodes in patients with malignant diseases always arouse suspicion of lymphatic metastases. Despite modern diagnostic investigation, surprising findings sometimes emerge. The present case of a young man with intrathoracic lesions in association with a germ-cell tumor of the testis turned out to have sarcoidosis mimicking testicular cancer relapse. PMID:18209992

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

    E-print Network

    Wessel, Gary M.

    The 30 UTR of nanos2 directs enrichment in the germ cell lineage of the sea urchin Nathalie Oulhen the GFP open reading frame followed by Sp nanos2 30 UTR leads to selective reporter enrichment increased the sMic reporter enrichment when present with the 30 UTR. We defined an element conserved between

  1. piggyBac transposition into primordial germ cells is an efficient tool for transgenesis in chickens

    PubMed Central

    Park, Tae Sub; Han, Jae Yong

    2012-01-01

    Transgenic birds embody one of the most potent and exciting research tools in biotechnology for agriculture, medicine, and model animals. To date, retrovirus- or lentivirus-mediated transgenesis has been established in chickens and quail. However, despite having a valid technique for viral transduction to achieve transgenic birds, many obstacles exist for practical applications because of relatively low and variable rates of germ-line transmission and transgenic offspring showing transgene silencing, as well as safety issues related to viral vector use. Thus, the generation of transgenic poultry by nonviral integration is a prerequisite for the introduction of biotechnology to practical applications. Herein, we show that a germ-line–competent chicken primordial germ-cell (PGC) line was established with high efficiency of transmission to offspring and that piggyBac transposition into PGCs improved the efficiency of transgenic chicken production and led to high-level transgene expression. GFP transgene-expressing donor PGC-transferred recipient chickens produced donor-derived progenies, and the germ-line transmission efficiency of donor PGCs was 95.2% on average. Subsequently, half of the donor-derived offspring (52.2%) were transgenic chicks because GFP-expressing donor PGCs, in which a transgene was inserted into one chromosome 20, were heterozygous. In all of the transgenic chickens, GFP expression was constant and strong, regardless of age. Our results demonstrate that piggyBac transposition into the chicken PGC line could be the surest way to generate transgenic chickens safely for practical applications. PMID:22645326

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

    E-print Network

    Pappu, Hanu R.

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

  3. Boule Is Present in Fish and Bisexually Expressed in Adult and Embryonic Germ Cells of Medaka

    PubMed Central

    Xu, Hongyan; Li, Zhendong; Li, Mingyou; Wang, Li; Hong, Yunhan

    2009-01-01

    Background The DAZ family genes boule, daz and dazl encode RNA binding proteins essential for fertility of diverse animals including human. dazl has bisexual expression in both mitotic and meiotic germ cells, whereas daz has male premeiotic expression, and boule is largely a unisexual meiotic regulator. Although boule has been proposed as the ancestor for dazl/daz by gene duplication, it has been identified only in invertebrates and mammals. It has, however, remained unclear when and how the DAZ family has evolved in vertebrates. Methodology and Principal Findings This study was aimed at identifying and characterizing the DAZ family genes in fish as the basal vertebrate. We show that boule and dazl coexist in medaka and stickleback. Similar to the medaka dazl (Odazl), the medaka boule (Obol) is maternally supplied and segregates with primordial germ cells. Surprisingly, Obol is expressed in adult germ cells at pre-meiotic and meiotic stages of spermatogenesis and oogenesis. However, the maximal meiotic Obol expression in spermatocytes contrasts with the predominant pre-meiotic Odazl expression in spermatogonia, and the diffuse cytoplasmic Obol distribution in early oocytes contrasts with the Odazl concentration in the Balbinani's body. Conclusions The identification of fish boule and dazl genes provides direct evidence for the early gene duplication during vertebrate evolution. Our finding that Obol exhibits bisexual expression in both embryonic and adult germ cells considerably extends the diversity of boule expression patterns and offers a new insight into the evolutions of DAZ family members, expression patterns and functions in animal fertility. PMID:19564913

  4. Current knowledge in the renewal capability of germ cells in the adult ovary.

    PubMed

    Oktem, Ozgur; Oktay, Kutluk

    2009-03-01

    It is a central dogma in reproductive biology that oogenesis is completed before or just after birth and that the postnatal ovary is endowed by a fixed and non-renewing number of oocytes in mammals. However, this widely accepted doctrine was recently challenged by studies showing regeneration of oocytes from putative germ cells in bone marrow and peripheral blood. These results not only triggered an enormous amount of interest among reproductive biologists but also a great deal of debate. In this review we will provide an update on the molecular aspects of the formation of primordial germ cells (PGC), the precursors of adult gametocytes, beginning from their specification to their migration to prospective gonads and formation of the ovary and follicular structures. We will also discuss more recent studies that showed in vivo regeneration of germ cells in the postnatal ovary in situ, along with other pioneering works that demonstrated generation of germ cells in vitro from embryonic and somatic stem cells. PMID:19306347

  5. Positive mRNA Translational Control in Germ Cells by Initiation Factor Selectivity

    PubMed Central

    Friday, Andrew J.; Keiper, Brett D.

    2015-01-01

    Ultimately, the production of new proteins in undetermined cells pushes them to new fates. Other proteins hold a stem cell in a mode of self-renewal. In germ cells, these decision-making proteins are produced largely from translational control of preexisting mRNAs. To date, all of the regulation has been attributed to RNA binding proteins (RBPs) that repress mRNAs in many models of germ cell development (Drosophila, mouse, C. elegans, and Xenopus). In this review, we focus on the selective, positive function of translation initiation factors eIF4E and eIF4G, which recruit mRNAs to ribosomes upon derepression. Evidence now shows that the two events are not separate but rather are coordinated through composite complexes of repressors and germ cell isoforms of eIF4 factors. Strikingly, the initiation factor isoforms are themselves mRNA selective. The mRNP complexes of translation factors and RBPs are built on specific populations of mRNAs to prime them for subsequent translation initiation. Simple rearrangement of the partners causes a dormant mRNP to become synthetically active in germ cells when and where they are required to support gametogenesis. PMID:26357652

  6. Angiotensin I Converting enzyme inhibitory peptides from commercial wet- and dry-milled corn germ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioprocesses were developed to enhance the value of proteins from de-oiled corn germ. Proteins were hydrolyzed with trypsin, GC106, Flavourzyme or thermolysin in order to free the bioactive peptide sequences. Protein hydrolysis, at an enzyme to substrate ratio of 1:250, was greater for wet- than d...

  7. CMV-driven expression of green uorescent protein (GFP) in male germ cells of transgenic mice

    E-print Network

    Museo Nacional de Ciencias Naturales

    CMV-driven expression of green ¯uorescent protein (GFP) in male germ cells of transgenic mice if the expression of green ¯uorescent protein (GFP) during sperma- togenesis can compromise the fertility of transgenic animals, we have produced mouse transgenic lines expressing GFP in the testis under the control

  8. 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

  9. Expression, sorting, and segregation of Golgi proteins during germ cell differentiation in the testis.

    PubMed

    Au, Catherine E; Hermo, Louis; Byrne, Elliot; Smirle, Jeffrey; Fazel, Ali; Simon, Paul H G; Kearney, Robert E; Cameron, Pamela H; Smith, Charles E; Vali, Hojatollah; Fernandez-Rodriguez, Julia; Ma, Kewei; Nilsson, Tommy; Bergeron, John J M

    2015-11-01

    The molecular basis of changes in structure, cellular location, and function of the Golgi apparatus during male germ cell differentiation is unknown. To deduce cognate Golgi proteins, we isolated germ cell Golgi fractions, and 1318 proteins were characterized, with 20 localized in situ. The most abundant protein, GL54D of unknown function, is characterized as a germ cell-specific Golgi-localized type II integral membrane glycoprotein. TM9SF3, also of unknown function, was revealed to be a universal Golgi marker for both somatic and germ cells. During acrosome formation, several Golgi proteins (GBF1, GPP34, GRASP55) localize to both the acrosome and Golgi, while GL54D, TM9SF3, and the Golgi trafficking protein TMED7/p27 are segregated from the acrosome. After acrosome formation, GL54D, TM9SF3, TMED4/p25, and TMED7/p27 continue to mark Golgi identity as it migrates away from the acrosome, while the others (GBF1, GPP34, GRASP55) remain in the acrosome and are progressively lost in later steps of differentiation. Cytoplasmic HSP70.2 and the endoplasmic reticulum luminal protein-folding enzyme PDILT are also Golgi recruited but only during acrosome formation. This resource identifies abundant Golgi proteins that are expressed differentially during mitosis, meiosis, and postacrosome Golgi migration, including the last step of differentiation. PMID:25808494

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    SciTech Connect

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

    1987-10-01

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

  12. Introduction Germ cells are a highly specialized lineage that is responsible

    E-print Network

    Blackwell, Keith

    . elegans, this cell death is referred to as physiological because the sacrificed nuclei do not seem et al., 1999). Although this suggests that the dying nuclei function in effect as nurse cells a pathway that culls defective germ cell nuclei in response to genotoxic stress (Gartner et al., 2000

  13. Maternal age effect and severe germ-line bottleneck in the inheritance of human mitochondrial DNA

    E-print Network

    Nielsen, Rasmus

    Maternal age effect and severe germ-line bottleneck in the inheritance of human mitochondrial DNA September 8, 2014 (received for review May 20, 2014) The manifestation of mitochondrial DNA (mtDNA) diseases The centerpiece of cellular metabolic machinery--the mito- chondrion--harbors a 16.5-kb genome, mitochondrial DNA

  14. Maintaining a Sanitary Child Care Environment -- Six Tips for Germ Control.

    ERIC Educational Resources Information Center

    Aronson, Susan S.

    2001-01-01

    Recommends keeping body defenses strong, and keeping all surfaces clean and some surfaces sanitary. Urges using federally mandated precautions for blood spills, avoiding germ-trapping artificial or long fingernails and jewelry, practicing good hand washing, and organizing the environment to avoid contamination. Includes table relating child care…

  15. ANEUPLOIDIES AND MICRONUCLEI IN THE GERM CELLS OF MALE MICE OF ADVANCED AGE

    EPA Science Inventory

    The objective of this research was to determine whether the frequencies of chromosomally defective germ cells increased with age in male laboratory mice. wo types of chromosomal abnormalities were characterized: (1) testicular spermatid aneuploidy (TSA) as measured by a new metho...

  16. A current view of the epigenome in mouse primordial germ cells.

    PubMed

    Matsui, Yasuhisa; Mochizuki, Kentaro

    2014-02-01

    Primordial germ cells (PGCs) are undifferentiated germ line cells in embryos that emerge at early stages of embryonic development, and then differentiate into eggs or sperm in gonads to give rise to individuals of successive generations. During germ cell development, several dynamic changes in epigenetic modifications including DNA methylation and histone modifications occur, and these changes are thought to be reprogramming processes that are required for germ cells to confer totipotency to the zygote. Initially, the epigenetic status of particular gene loci in PGCs was studied, but more recently, genome-wide studies have provided more comprehensive views of the PGC epigenome. Mouse PGCs undergo global DNA demethylation that starts shortly after PGC specification in early embryos. Although the functional importance of global DNA demethylation is not fully understood, demethylation of imprinted genes is crucial for erasure of methylation-based imprinting, and demethylation of PGC-specific genes is crucial for proper transcriptional regulation. PGCs also have unique patterns of histone modification, such as hypomethylation of H3K9 and hypermethylation of H3K27, and experimental evidence suggests that the unique epigenetic modifications of histones are important to the proper development of PGCs. PMID:23868517

  17. Pathogenesis of PCV2a and PCV2b virus in germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic analysis of porcine circovirus type 2 (PCV2) reveals 2 subgroups that will be referred to as PCV2a and PCV2b representing the North American and European prototypes respectfully. This paper summarizes 3 studies comparing the pathogenesis of 2a and 2b viruses in germ-free pigs. In this PCV2...

  18. The current algebra on the circle as a germ of local field theories

    NASA Astrophysics Data System (ADS)

    Buchholz, Detlev; Mack, Gerhard; Todorov, Ivan

    1988-12-01

    Methods of algebraic quantum field theory are used to classify all field- and observable algebras, whose common germ is the U(1)-current algebra. An elementary way is described to compute characters of such algebras. It exploits the Kubo-Martin-Schwinger condition for Gibbs states..

  19. A Livšic type theorem for germs of analytic diffeomorphisms

    NASA Astrophysics Data System (ADS)

    Navas, Andrés; Ponce, Mario

    2013-01-01

    We deal with the problem of the validity of the Livšic theorem for cocycles of diffeomorphisms over a hyperbolic dynamics that satisfy the periodic orbit condition. We give a result in the positive direction for cocycles of germs of analytic diffeomorphisms at the origin.

  20. USE OF MUELLER-HINTON BROTH AND AGAR IN THE GERM TUBE TEST

    PubMed Central

    Mattei, Antonella Souza; Alves, Sydney Hartz; Severo, Cecília Bittencourt; Guazzelli, Luciana da Silva; Oliveira, Flávio de Mattos; Severo, Luiz Carlos

    2014-01-01

    Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT) test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis). The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH) broth and agar. GT was observed in 96% (130/136) of the isolates through the fresh serum technique, 94% (128/136) through previously frozen serum, 92% (125/136) in MH agar, and 90% (122/136) in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test. PMID:25351541

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Wheat germ oil in larval diet influences gene expression in adult oriental fruit fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culture media supplemented with wheat germ oil (WGO) exerts observable physiological reactions, such as increased fecundity and mobility, in some insects. Although the impact of WGO on insect physiology is important, the mechanisms of these actions are poorly understood. The hypothesis that the ad...

  3. SHORT REPORT Open Access No additional copies of HERV-Fc1 in the germ line

    E-print Network

    Schierup, Mikkel Heide

    SHORT REPORT Open Access No additional copies of HERV-Fc1 in the germ line of multiple sclerosis of multiple sclerosis (MS). This suspicion has in part been based on increased expression of viral RNA this provirus and multiples sclerosis. Keywords: HERV-Fc1, Multiple sclerosis, Provirus copy-number Findings

  4. Robust In Vitro Induction of Human Germ Cell Fate from Pluripotent Stem Cells.

    PubMed

    Sasaki, Kotaro; Yokobayashi, Shihori; Nakamura, Tomonori; Okamoto, Ikuhiro; Yabuta, Yukihiro; Kurimoto, Kazuki; Ohta, Hiroshi; Moritoki, Yoshinobu; Iwatani, Chizuru; Tsuchiya, Hideaki; Nakamura, Shinichiro; Sekiguchi, Kiyotoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Mori, Takahide; Woltjen, Knut; Nakagawa, Masato; Yamamoto, Takuya; Takahashi, Kazutoshi; Yamanaka, Shinya; Saitou, Mitinori

    2015-08-01

    Mechanisms underlying human germ cell development are unclear, partly due to difficulties in studying human embryos and lack of suitable experimental systems. Here, we show that human induced pluripotent stem cells (hiPSCs) differentiate into incipient mesoderm-like cells (iMeLCs), which robustly generate human primordial germ cell-like cells (hPGCLCs) that can be purified using the surface markers EpCAM and INTEGRIN?6. The transcriptomes of hPGCLCs and primordial germ cells (PGCs) isolated from non-human primates are similar, and although specification of hPGCLCs and mouse PGCs rely on similar signaling pathways, hPGCLC specification transcriptionally activates germline fate without transiently inducing eminent somatic programs. This includes genes important for naive pluripotency and repression of key epigenetic modifiers, concomitant with epigenetic reprogramming. Accordingly, BLIMP1, which represses somatic programs in mice, activates and stabilizes a germline transcriptional circuit and represses a default neuronal differentiation program. Together, these findings provide a foundation for understanding and reconstituting human germ cell development in vitro. PMID:26189426

  5. Transcriptional Signatures in Response to Wheat Germ Agglutinin and Starvation in Drosophila melanogaster Larval Midgut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One function of plant lectins such as wheat germ agglutinin (WGA) is to serve as defenses against herbivorous insects. The midgut is one critical site affected by dietary lectins. We observed marked cellular, structural, and gene expression changes in the midguts of Drosophila melanogaster third-i...

  6. Biological characteristics of fish germ cells and their application to developmental biotechnology.

    PubMed

    Yoshizaki, G; Okutsu, T; Morita, T; Terasawa, M; Yazawa, R; Takeuchi, Y

    2012-08-01

    We have revealed several unique characteristics of germ cell development using rainbow trout, including the fact that spermatogonia transplanted into the peritoneal cavity of newly hatched embryos migrate toward recipient gonads, that spermatogonia transplanted into female recipients start oogenesis and produce functional eggs and that diploid germ cells transplanted into triploid trout can complete gametogenesis. By combining these unique features of fish germ cells, we established allogeneic and xenogeneic transplantation systems for spermatogonia in several fish species. Spermatogonia isolated from the mature testes of vasa-green fluorescent protein (Gfp) transgenic rainbow trout were transplanted into the peritoneal cavity of triploid masu salmon newly hatched embryos. These spermatogonia migrated toward recipient salmon genital ridges with extending pseudopodia and were subsequently incorporated into them. We further confirmed that the donor-derived spermatogonia resumed gametogenesis and produced sperm and eggs in male and female salmon recipients, respectively. By inseminating the resulting eggs and sperm, we obtained only rainbow trout offspring in the F1 generation, suggesting that the triploid salmon recipients produced functional gametes derived only from donor trout. We further confirmed that this intra-peritoneal transplantation of germ cells is applicable to several marine fishes, which could be of benefit in the production of bluefin tuna that has a large broodstock (>100 kg) and is difficult to maintain in captivity. Gamete production of bluefin tuna could be more easily achieved by generating a surrogate species, such as mackerel, that can produce tuna gametes. PMID:22827369

  7. The problem of the origin of primordial germ cells (PGCs) in vertebrates: historical review and a possible solution.

    PubMed

    Pilato, Giovanni; D'Urso, Vera; Viglianisi, Fabio; Sammartano, Francesca; Sabella, Giorgio; Lisi, Oscar

    2013-01-01

    A concise review of the articles about the origin of primordial germ cells (PGCs) in vertebrates is provided. Differences among various taxa concerning the origin of PGCs, not easily understandable on the base of traditional knowledge, are pointed out. All those differences can be explained taking into consideration the recent ?theory of the endoderm as secondary layer?. That theory allows us to understand that those differences are only apparent, being related to modifications of stages of the consequent embryogeny, overall, to a different amount of yolk in the egg. Eggs very rich in yolk became meroblastic, and the portion of primordial ectomesenchyme destined to give rise to a part of the mesoderm and the PGCs separates early from the part destined to give rise to the rest of the mesoderm and to the digestive endoderm in order to form the vitelline hypoblast lamina. To this lamina, in contrast to the traditional interpretation, a mesodermal, not endodermal, origin must be attributed. With the misunderstanding regarding the origin of this lamina clarified, all the differences about the origin of PGCs disappears. Furthermore, in taxa where PGCs were considered to be of endodermal origin, they too have a mesodermal origin. Considering that a mesodermal origin of PGCs has been demonstrated in all sponges and cnidarians, as well, a unique, mesodermal origin of germinal cells in all pluricellular animals results. PMID:24623072

  8. A small RNA in testis and brain: implications for male germ cell development.

    PubMed

    Muslimov, Ilham A; Lin, Yuan; Heller, Michal; Brosius, Jürgen; Zakeri, Zahra; Tiedge, Henri

    2002-03-15

    BC1 RNA, a small non-coding RNA polymerase III transcript, is selectively targeted to dendritic domains of a subset of neurons in the rodent nervous system. It has been implicated in the regulation of local protein synthesis in postsynaptic microdomains. The gene encoding BC1 RNA has been suggested to be a master gene for repetitive ID elements that are found interspersed throughout rodent genomes. A prerequisite for the generation of repetitive elements through retroposition and subsequent transmission in the germline is expression of the master gene RNA in germ cells. To test this hypothesis, we have investigated expression of BC1 RNA in murine male germ cells. We report that BC1 RNA is expressed at substantial levels in a subset of male germ cells. Results from cell fractionation experiments, developmental analysis, and northern and in situ hybridization showed that the RNA was expressed in pre-meiotic spermatogonia, with particularly high amounts in syncytial ensembles of cells that are primed for synchronous spermatogenic differentiation. BC1 RNA continued to be expressed in spermatocytes, but expression levels decreased during further spermatogenic development, and low or negligible amounts of BC1 RNA were identified in round and elongating spermatids. The combined data indicate that BC1 RNA operates in groups of interconnected germ cells, including spermatogonia, where it may function in the mediation of translational control. At the same time, the identification of BC1 RNA in germ cells provides essential support for the hypothesis that repetitive ID elements in rodent genomes arose from the BC1 RNA gene through retroposition. PMID:11884523

  9. Spondyloepiphseal dysplasia congenita in siblings born to unaffected parents: ? germ line mosaicism

    SciTech Connect

    Mulla, W.; McDonald-McGinn, D.; Zackai, E.

    1994-09-01

    Germ line mosaicism has been used to explain the birth of more than one child affected with a dominantly inherited disorder born to unaffected parents. Furthermore, it has been confirmed clinically in families where recurrence in siblings was originally thought to be autosomal recessive, but were affected individuals have reproduced affected offspring. Firm evidence of germ line mosaicism using mutation analysis by molecular methods exists for some autosomal disorders. We present two siblings with spondyloepipheseal dysplasia congenita (SEDC) born to unaffected parents. This suggests the presence of germ line mosaicism in this entity. Patient 1 was born at 32 weeks gestation to a G1P1 Puerto Rican mother. The pregnancy was complicated by polyhydramnios. The neonate, a short-limbed dwarf, died at 15 hours of age from respiratory distress and a compromised thoracic cavity. Patient 2, the sibling of patient 1 was born at 37 weeks gestation after a pregnancy complicated by polyhydramnios and prenatal ultrasound diagnosis of short-limbed dwarfism. The diagnosis of SEDC was made and, after review of the sibling`s postmortem X-rays, it was felt that she was similarly affected. The family history reveals no history of dwarfism or consanguinity. The SEDC is described as an autosomal dominant form of dwarfism with variable presentation including some cases that have been lethal in the neonatal period. SEDC is now believed to represent a family of collagen II mutations. Sporadic cases that have arisen in families with no history have been ascribed to new heterozygous mutations. Other families in which SEDC and SEMD recurred without a family history most likely represent germ line mosaicism. In these cases molecular studies should be pursued to document a collagen II mutation. We believe that germ line mosaicism is the most plausible explanation for recurrence in our family.

  10. Pituitary blastoma: a pathognomonic feature of germ-line DICER1 mutations

    PubMed Central

    de Kock, Leanne; Sabbaghian, Nelly; Plourde, François; Srivastava, Archana; Weber, Evan; Soglio, Dorothée Bouron-Dal; Hamel, Nancy; Choi, Joon Hyuk; Park, Sung-Hye; Deal, Cheri L.; Kelsey, Megan M.; Dishop, Megan K.; Esbenshade, Adam; Kuttesch, John F.; Jacques, Thomas S.; Perry, Arie; Leichter, Heinz; Maeder, Philippe; Brundler, Marie-Anne; Warner, Justin; Neal, James; Zacharin, Margaret; Korbonits, Márta; Cole, Trevor; Traunecker, Heidi; McLean, Thomas W.; Rotondo, Fabio; Lepage, Pierre; Albrecht, Steffen; Horvath, Eva; Kovacs, Kalman; Priest, John R.; Foulkes, William D.

    2014-01-01

    Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5? arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 “hits” occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis. PMID:24839956

  11. DDX4 (VASA) is conserved in germ cell development in marsupials and monotremes.

    PubMed

    Hickford, Danielle E; Frankenberg, Stephen; Pask, Andrew J; Shaw, Geoff; Renfree, Marilyn B

    2011-10-01

    DDX4 (VASA) is an RNA helicase expressed in the germ cells of all animals. To gain greater insight into the role of this gene in mammalian germ cell development, we characterized DDX4 in both a marsupial (the tammar wallaby) and a monotreme (the platypus). DDX4 is highly conserved between eutherian, marsupial, and monotreme mammals. DDX4 protein is absent from tammar fetal germ cells but is present from Day 1 postpartum in both sexes. The distribution of DDX4 protein during oogenesis and spermatogenesis in the tammar is similar to eutherians. Female tammar germ cells contain DDX4 protein throughout all stages of postnatal oogenesis. In males, DDX4 is in gonocytes, and during spermatogenesis it is present in spermatocytes and round spermatids. A similar distribution of DDX4 occurs in the platypus during spermatogenesis. There are several DDX4 isoforms in the tammar, resulting from both pre- and posttranslational modifications. DDX4 in marsupials and monotremes has multiple splice variants and polyadenylation motifs. Using in silico analyses of genomic databases, we found that these previously unreported splice variants also occur in eutherians. In addition, several elements implicated in the control of Ddx4 expression in the mouse, including RGG (arginine-glycine-glycine) and dimethylation of arginine motifs and CpG islands within the Ddx4 promoter, are also highly conserved. Collectively these data suggest that DDX4 is essential for the regulation of germ cell proliferation and differentiation across all three extant mammalian groups-eutherians, marsupials, and monotremes. PMID:21653890

  12. Serotonin receptors are selectively expressed in the avian germ cells and early embryos.

    PubMed

    St?pi?ska, Urszula; Kuwana, Takashi; Olsza?ska, Bo?enna

    2015-06-01

    The expression of nine serotonin (5-HT) receptor transcripts was studied using reverse transcription polymerase chain reaction (RT-PCR) in germ cells, cleavage and gastrulation stages of Japanese quail, and qPCR for 5-HT3 and 5-HT4 receptors in oocytes and embryos. We show the presence/absence of nine serotonin transcripts known in birds for receptors 5-HT1A, 5-HT1F, 5-HT2B, 5-HT2C, 5-HT3, 5-HT4, 5-HT5A, 5-HT6 and 5-HT7A in avian germ cells and early embryos. The absence of 5-HT3 and 5-HT5A in primordial germ cells and of 5-HT3 and 5-HT7A in sperm is characteristic. All transcripts appeared in oocytes at all stages (except for 5-HT3 and 5-HT5A transcripts) and all were present in cleaving embryos and at gastrulation, except for 5-HT3, which was permanently observed as late as in stage 4. Interestingly, 5-HT3 and 5-HT5A receptors accumulated in 3-mm and F1 oocytes but were degraded at ovulation and started to be re-transcribed in cleavage stage II embryos and beyond. The selective appearance of 5-HT receptors in germ cells and early embryos supports the hypothesis that serotonin may act as a signalling molecule at early stages of germ line and embryo differentiation via individual receptors present during different stages, when specialized communication systems are not yet developed. PMID:24521994

  13. Three-Step Method for Proliferation and Differentiation of Human Embryonic Stem Cell (hESC)-Derived Male Germ Cells

    PubMed Central

    Lim, Jung Jin; Shim, Myung Sun; Lee, Jeoung Eun; Lee, Dong Ryul

    2014-01-01

    The low efficiency of differentiation into male germ cell (GC)-like cells and haploid germ cells from human embryonic stem cells (hESCs) reflects the culture method employed in the two-dimensional (2D)-microenvironment. In this study, we applied a three-step media and calcium alginate-based 3D-culture system for enhancing the differentiation of hESCs into male germ stem cell (GSC)-like cells and haploid germ cells. In the first step, embryoid bodies (EBs) were derived from hESCs cultured in EB medium for 3 days and re-cultured for 4 additional days in EB medium with BMP4 and RA to specify GSC-like cells. In the second step, the resultant cells were cultured in GC-proliferation medium for 7 days. The GSC-like cells were then propagated after selection using GFR-?1 and were further cultured in GC-proliferation medium for 3 weeks. In the final step, a 3D-co-culture system using calcium alginate encapsulation and testicular somatic cells was applied to induce differentiation into haploid germ cells, and a culture containing approximately 3% male haploid germ cells was obtained after 2 weeks of culture. These results demonstrated that this culture system could be used to efficiently induce GSC-like cells in an EB population and to promote the differentiation of ESCs into haploid male germ cells. PMID:24690677

  14. Germ plasm localisation of the HELICc of Vasa in Drosophila: analysis of domain sufficiency and amino acids critical for localisation

    PubMed Central

    Wang, Szu-Chieh; Hsu, Hao-Jen; Lin, Gee-way; Wang, Ting-Fang; Chang, Chun-che; Lin, Ming-Der

    2015-01-01

    Formation of the germ plasm drives germline specification in Drosophila and some other insects such as aphids. Identification of the DEAD-box protein Vasa (Vas) as a conserved germline marker in flies and aphids suggests that they share common components for assembling the germ plasm. However, to which extent the assembly order is conserved and the correlation between functions and sequences of Vas remain unclear. Ectopic expression of the pea aphid Vas (ApVas1) in Drosophila did not drive its localisation to the germ plasm, but ApVas1 with a replaced C-terminal domain (HELICc) of Drosophila Vas (DmVas) became germ-plasm restricted. We found that HELICc itself, through the interaction with Oskar (Osk), was sufficient for germ-plasm localisation. Similarly, HELICc of the grasshopper Vas could be recruited to the germ plasm in Drosophila. Nonetheless, germ-plasm localisation was not seen in the Drosophila oocytes expressing HELICcs of Vas orthologues from aphids, crickets, and mice. We further identified that glutamine (Gln) 527 within HELICc of DmVas was critical for localisation, and its corresponding residue could also be detected in grasshopper Vas yet missing in the other three species. This suggests that Gln527 is a direct target of Osk or critical to the maintenance of HELICc conformation. PMID:26419889

  15. Germ plasm localisation of the HELICc of Vasa in Drosophila: analysis of domain sufficiency and amino acids critical for localisation

    NASA Astrophysics Data System (ADS)

    Wang, Szu-Chieh; Hsu, Hao-Jen; Lin, Gee-Way; Wang, Ting-Fang; Chang, Chun-Che; Lin, Ming-Der

    2015-09-01

    Formation of the germ plasm drives germline specification in Drosophila and some other insects such as aphids. Identification of the DEAD-box protein Vasa (Vas) as a conserved germline marker in flies and aphids suggests that they share common components for assembling the germ plasm. However, to which extent the assembly order is conserved and the correlation between functions and sequences of Vas remain unclear. Ectopic expression of the pea aphid Vas (ApVas1) in Drosophila did not drive its localisation to the germ plasm, but ApVas1 with a replaced C-terminal domain (HELICc) of Drosophila Vas (DmVas) became germ-plasm restricted. We found that HELICc itself, through the interaction with Oskar (Osk), was sufficient for germ-plasm localisation. Similarly, HELICc of the grasshopper Vas could be recruited to the germ plasm in Drosophila. Nonetheless, germ-plasm localisation was not seen in the Drosophila oocytes expressing HELICcs of Vas orthologues from aphids, crickets, and mice. We further identified that glutamine (Gln) 527 within HELICc of DmVas was critical for localisation, and its corresponding residue could also be detected in grasshopper Vas yet missing in the other three species. This suggests that Gln527 is a direct target of Osk or critical to the maintenance of HELICc conformation.

  16. Germ plasm localisation of the HELICc of Vasa in Drosophila: analysis of domain sufficiency and amino acids critical for localisation.

    PubMed

    Wang, Szu-Chieh; Hsu, Hao-Jen; Lin, Gee-way; Wang, Ting-Fang; Chang, Chun-che; Lin, Ming-Der

    2015-01-01

    Formation of the germ plasm drives germline specification in Drosophila and some other insects such as aphids. Identification of the DEAD-box protein Vasa (Vas) as a conserved germline marker in flies and aphids suggests that they share common components for assembling the germ plasm. However, to which extent the assembly order is conserved and the correlation between functions and sequences of Vas remain unclear. Ectopic expression of the pea aphid Vas (ApVas1) in Drosophila did not drive its localisation to the germ plasm, but ApVas1 with a replaced C-terminal domain (HELICc) of Drosophila Vas (DmVas) became germ-plasm restricted. We found that HELICc itself, through the interaction with Oskar (Osk), was sufficient for germ-plasm localisation. Similarly, HELICc of the grasshopper Vas could be recruited to the germ plasm in Drosophila. Nonetheless, germ-plasm localisation was not seen in the Drosophila oocytes expressing HELICcs of Vas orthologues from aphids, crickets, and mice. We further identified that glutamine (Gln) 527 within HELICc of DmVas was critical for localisation, and its corresponding residue could also be detected in grasshopper Vas yet missing in the other three species. This suggests that Gln527 is a direct target of Osk or critical to the maintenance of HELICc conformation. PMID:26419889

  17. Activation of the germ-cell potential of human bone marrow-derived cells by a chemical carcinogen

    PubMed Central

    Liu, Chunfang; Ma, Zhan; Xu, Songtao; Hou, Jun; Hu, Yao; Yu, Yinglu; Liu, Ruilai; Chen, Zhihong; Lu, Yuan

    2014-01-01

    Embryonic/germ cell traits are common in malignant tumors and are thought to be involved in malignant tumor behaviors. The reasons why tumors show strong embryonic/germline traits (displaced germ cells or gametogenic programming reactivation) are controversial. Here, we show that a chemical carcinogen, 3-methyl-cholanthrene (3-MCA), can trigger the germ-cell potential of human bone marrow-derived cells (hBMDCs). 3-MCA promoted the generation of germ cell-like cells from induced hBMDCs that had undergone malignant transformation, whereas similar results were not observed in the parallel hBMDC culture at the same time point. The malignant transformed hBMDCs spontaneously and more efficiently generated into germ cell-like cells even at the single-cell level. The germ cell-like cells from induced hBMDCs were similar to natural germ cells in many aspects, including morphology, gene expression, proliferation, migration, further development, and teratocarcinoma formation. Therefore, our results demonstrate that a chemical carcinogen can reactivate the germline phenotypes of human somatic tissue-derived cells, which might provide a novel idea to tumor biology and therapy. PMID:24998261

  18. Spallanzani Layers

    NASA Technical Reports Server (NTRS)

    2006-01-01

    31 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a layered, light-toned mesa among other layered materials exposed in a mound that covers much of the floor of Spallanzani Crater.

    Location near: 58.3oS, 273.9oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

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

    E-print Network

    Jobling, Matthew S.

    2010-01-01

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

  20. The Ligand Binding Domain of GCNF Is Not Required for Repression of Pluripotency Genes in Mouse Fetal Ovarian Germ Cells

    E-print Network

    Okumura, Leah M.

    In mice, successful development and reproduction require that all cells, including germ cells, transition from a pluripotent to a differentiated state. This transition is associated with silencing of the pluripotency genes ...

  1. The fate of isolated blastomeres with respect to germ cell formation in the amphipod crustacean Parhyale hawaiensis

    E-print Network

    Extavour, Cassandra

    , either autonomously by oocytes or by associated nutritive cells. In Drosophila, each oocyte is connected: undifferentiated cells receive an inductive signal from neighboring tissues and respond by differentiating as germ

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

    E-print Network

    Gill, Mark E.

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

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

    SciTech Connect

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

    1991-09-01

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

  4. STAGE-SPECIFIC DAMAGE TO SYNAPTONEMAL COMPLEXES AND METAPHASE CHROMOSOME INDUCED BY X RAYS IN MALE MOUSE GERM CELLS

    EPA Science Inventory

    Synaptonemal complexes (SCs) reveal mutagen-induced effects in germ cell meiotic chromosomes. his study was aimed at characterizing relationships between SC and metaphase I chromosome damage following radiation exposure at various stages of spermatogenesis. Male mice were irradia...

  5. Posterior localization of ApVas1 positions the preformed germ plasm in the sexual oviparous pea aphid Acyrthosiphon pisum

    PubMed Central

    2014-01-01

    Background Germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid or late development (induction mode). In the Metazoa, the induction mode appears as a more prevalent and ancestral condition; the inheritance mode is therefore derived. However, regarding germline specification in organisms with asexual and sexual reproduction it has not been clear whether both strategies are used, one for each reproductive phase, or if just one strategy is used for both phases. Previously we have demonstrated that specification of germ cells in the asexual viviparous pea aphid depends on a preformed germ plasm. In this study, we extended this work to investigate how germ cells were specified in the sexual oviparous embryos, aiming to understand whether or not developmental plasticity of germline specification exists in the pea aphid. Results We employed Apvas1, a Drosophila vasa ortholog in the pea aphid, as a germline marker to examine whether germ plasm is preformed during oviparous development, as has already been seen in the viviparous embryos. During oogenesis, Apvas1 mRNA and ApVas1 protein were both evenly distributed. After fertilization, uniform expression of Apvas1 remained in the egg but posterior localization of ApVas1 occurred from the fifth nuclear cycle onward. Posterior co-localization of Apvas1/ApVas1 was first identified in the syncytial blastoderm undergoing cellularization, and later we could detect specific expression of Apvas1/ApVas1 in the morphologically identifiable germ cells of mature embryos. This suggests that Apvas1/ApVas1-positive cells are primordial germ cells and posterior localization of ApVas1 prior to cellularization positions the preformed germ plasm. Conclusions We conclude that both asexual and sexual pea aphids rely on the preformed germ plasm to specify germ cells and that developmental plasticity of germline specification, unlike axis patterning, occurs in neither of the two aphid reproductive phases. Consequently, the maternal inheritance mode implicated by a preformed germ plasm in the oviparous pea aphid becomes a non-canonical case in the Hemimetabola, where so far the zygotic induction mode prevails in most other studied insects. PMID:24855557

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

    PubMed

    Brorson, Stig

    2006-01-01

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

  7. Active DNA demethylation is required for complete imprint erasure in primordial germ cells.

    PubMed

    Kawasaki, Yuki; Lee, Jiyoung; Matsuzawa, Ayumi; Kohda, Takashi; Kaneko-Ishino, Tomoko; Ishino, Fumitoshi

    2014-01-01

    In mammalian primordial germ cells (PGCs), DNA demethylation is indispensible for parental imprint erasure, which is a reprogramming process essential for normal developmental potential. Thus, it is important to elucidate how DNA demethylation occurs in each imprinted region in PGCs and to determine which DNA demethylation pathway, passive or active, essentially contributes to the erasure of the imprint. Here, we report that active DNA demethylation via a putative Poly(ADP-ribose) polymerase (PARP) pathway is involved in H19-DMR imprint erasure in PGCs, as shown by an in vivo small molecule inhibitor assay. To the best of our knowledge, this is the first direct demonstration of a DNA replication-independent active DNA demethylation pathway in the erasure process of genomic imprinting in PGCs in vivo. The data also suggest that active DNA demethylation plays a significant role in the complete erasure of paternal imprinting in the female germ line. PMID:24413819

  8. Effects of dppa3 on DNA methylation dynamics during primordial germ cell development in mice.

    PubMed

    Nakashima, Hiroyuki; Kimura, Tohru; Kaga, Yoshiaki; Nakatani, Tsunetoshi; Seki, Yoshiyuki; Nakamura, Toshinobu; Nakano, Toru

    2013-05-01

    DNA methylation is a central epigenetic event that regulates cellular differentiation, reprogramming, and pathogenesis. Genomewide DNA demethylation occurs in preimplantation embryos and in embryonic germ cell precursors called primordial germ cells (PGCs). We previously showed that Dppa3, also known as Stella and PGC7, protects the maternal genome from tet methylcytosine dioxygenase 3 (Tet3)-mediated conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in zygotes. Here, we demonstrated that retrotransposon genes, such as long interspersed nuclear element-1 (Line-1) and intracisternal A particle (IAP), showed higher 5mC levels in Dppa3-null PGCs. In contrast, oxidative bisulfite sequence analysis revealed that the amounts of 5hmC in Line-1 and IAP were slightly reduced in the Dppa3-deficient PGCs. From our findings, we propose that Dppa3 is involved in the Tet-mediated active demethylation process during reprogramming of PGCs. PMID:23595900

  9. Wheat germ lectin affinity electrophoresis of serum alkaline phosphatase with commercially available agarose gels.

    PubMed

    Mattiazzo, M; Ramasamy, I

    1993-07-01

    We have modified a commercially available procedure involving precast agarose gels (Paragon Isopal System) to measure alkaline phosphatase (EC 3.1.3.1) isoenzymes. Including wheat germ lectin in the equilibration buffer improved the resolution of the bone and liver isoenzymes. Unlike previously described wheat germ lectin affinity electrophoresis methods, the procedure measures bone, liver, and biliary isoenzymes in a single step. There was good correlation between the affinity electrophoresis and the neuraminidase preincubation methods for the measurement of bone (r = 0.958) and liver (r = 0.962) alkaline phosphatase isoenzymes. However, the affinity electrophoresis method also quantified minor isoenzyme fractions that were poorly resolved by the neuraminidase method. The method is technically simple, reproducible, and capable of rapid handling of large workloads. PMID:8330397

  10. Genetic modification of the human germ line: The reasons why this project has no future.

    PubMed

    Morange, Michel

    2015-01-01

    Modification of the human germ line has remained a distant but valuable objective for most biologists since the emergence of genetics (and even before). To study the historical transformations of this project, I have selected three periods - the 1930s, at the pinnacle of eugenics, around 1974 when molecular biology triumphed, and today - and have adopted three criteria to estimate the feasibility of this project: the state of scientific knowledge, the existence of suitable tools, and societal demands. Although the long-awaited techniques to modify the germ line are now available, I will show that most of the expectations behind this project have disappeared, or are considered as being reachable by highly different strategies. PMID:26231145

  11. Peroxiredoxin stabilization of DE-Cadherin promotes primordial germ cell adhesion

    PubMed Central

    DeGennaro, Matthew; Hurd, Thomas Ryan; Siekhaus, Daria Elisabeth; Biteau, Benoit; Jasper, Heinrich; Lehmann, Ruth

    2011-01-01

    Summary Regulated adhesion between cells and their environment is critical for normal cell migration. We have identified mutations in a gene encoding the Drosophila hydrogen peroxide (H2O2)-degrading enzyme Jafrac1, which lead to germ cell adhesion defects. During gastrulation, primordial germ cells (PGCs) associate tightly with the invaginating midgut primordium as it enters the embryo; however in embryos from jafrac1 mutant mothers this association is disrupted, leaving some PGCs trailing on the outside of the embryo. We observed similar phenotypes in embryos from DE-Cadherin/shotgun (shg) mutant mothers and were able to rescue the jafrac1 phenotype by increasing DE-Cadherin levels. This and our biochemical evidence strongly suggest that Jafrac1-mediated reduction of H2O2 is required to maintain DE-Cadherin protein levels in the early embryo. Our results present in vivo evidence of a peroxiredoxin regulating DE-Cadherin mediated adhesion. PMID:21316590

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  14. Distinct development patterns of c-mos protooncogene expression in female and male mouse germ cells

    SciTech Connect

    Mutter, G.L.; Wolgemuth, D.J.

    1987-08-01

    The protooncogene c-mos is expressed in murine reproductive tissues, producing transcripts of 1.7 and 1.4 kilobases in testis and ovary, respectively. In situ hybridization analysis of c-mos expression in histological sections of mouse ovaries revealed that oocytes are the predominant if not exclusive source of c-mos transcripts. /sup 35/S- or /sup 32/P-labelled RNA probes were transcribed. c-mos transcripts accumulate in growing oocytes, increasing 40- to 90-fold during oocyte and follicular development. c-mos transcripts were also detected in male germ cells and are most abundant after the cells have entered the haploid stage of spermatogenesis. This developmentally regulated pattern of c-mos expression in oocytes and spermatogenic cells suggest that the c-mos gene product may have a function in normal germ-cell differentiation or early embryogenesis.

  15. Identification of a Heritable Model of Testicular Germ Cell Tumor in the Zebrafish

    PubMed Central

    Neumann, Joanie C.; Dovey, Jennifer Shepard; Chandler, Garvin L.; Carbajal, Liliana

    2009-01-01

    Abstract Germ cell tumors (GCTs) affect infants, children, and adults and are the most common cancer type in young men. Progress in understanding the molecular basis of GCTs has been hampered by a lack of suitable animal models. Here we report the identification of a zebrafish model of highly penetrant, heritable testicular GCT isolated as part of a forward genetic screen for cancer susceptibility genes. The mutant line develops spontaneous testicular tumors at a median age of 7 months, and pedigree analysis indicates dominant inheritance of the GCT susceptibility trait. The zebrafish model exhibits disruption of testicular tissue architecture and the accumulation of primitive, spermatogonial-like cells with loss of spermatocytic differentiation. Radiation treatment leads to apoptosis of the tumor cells and tumor regression. The GCT-susceptible line can serve as a model for understanding the mechanisms regulating germ cells in normal development and disease and as a platform investigating new therapeutic approaches for GCTs. PMID:20047465

  16. Early Depletion of Primordial Germ Cells in Zebrafish Promotes Testis Formation

    PubMed Central

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

    2014-01-01

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

  17. Genome-wide reprogramming in the mouse germ line entails the base excision repair pathway.

    PubMed

    Hajkova, Petra; Jeffries, Sean J; Lee, Caroline; Miller, Nigel; Jackson, Stephen P; Surani, M Azim

    2010-07-01

    Genome-wide active DNA demethylation in primordial germ cells (PGCs), which reprograms the epigenome for totipotency, is linked to changes in nuclear architecture, loss of histone modifications, and widespread histone replacement. Here, we show that DNA demethylation in the mouse PGCs is mechanistically linked to the appearance of single-stranded DNA (ssDNA) breaks and the activation of the base excision repair (BER) pathway, as is the case in the zygote where the paternal pronucleus undergoes active DNA demethylation shortly after fertilization. Whereas BER might be triggered by deamination of a methylcytosine (5mC), cumulative evidence indicates other mechanisms in germ cells. We demonstrate that DNA repair through BER represents a core component of genome-wide DNA demethylation in vivo and provides a mechanistic link to the extensive chromatin remodeling in developing PGCs. PMID:20595612

  18. Molecular targets, DNA breakage, DNA repair: Their roles in mutation induction in mammalian germ cells

    SciTech Connect

    Sega, G.A.

    1989-01-01

    Variability in genetic sensitivity among different germ-cell stages in the mammal to various mutagens could be the result of how much chemical reaches the different stages, what molecular targets may be affected in the different stages and whether or not repair of lesions occurs. Several chemicals have been found to bind very strongly to protamine in late-spermatid and early-spermatozoa stages in the mouse. The chemicals also produce their greatest genetic damage in these same germ-cell stages. While chemical binding to DNA has not been correlated with the level of induced genetic damage, DNA breakage in the sensitive stages has been shown to increase. This DNA breakage is believed to indirectly result from chemical binding to sulfhydryl groups in protamine which prevents normal chromatin condensation within the sperm nucleus. 22 refs., 5 figs.

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

    SciTech Connect

    Fan Jun; Akabane, Hiroto; Zheng Xuehai; Zhou Xuan; Zhang Li; Liu Qiang; Zhang Yonglian; Yang Jing; Zhu Guozhang

    2007-11-23

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

  20. Differential Expression of Conserved Germ Line Markers and Delayed Segregation of Male and Female Primordial Germ Cells in a Hermaphrodite, the Leech Helobdella

    PubMed Central

    Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A.

    2014-01-01

    In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals. PMID:24217283

  1. The ontogeny of cKIT+ human primordial germ cells proves to be a resource for human germ line reprogramming, imprint erasure and in vitro differentiation.

    PubMed

    Gkountela, Sofia; Li, Ziwei; Vincent, John J; Zhang, Kelvin X; Chen, Angela; Pellegrini, Matteo; Clark, Amander T

    2013-01-01

    The generation of research-quality, clinically relevant cell types in vitro from human pluripotent stem cells requires a detailed understanding of the equivalent human cell types. Here we analysed 134 human embryonic and fetal samples from 6 to 20 developmental weeks and identified the stages at which cKIT(+) primordial germ cells (PGCs), the precursors of gametes, undergo whole-genome epigenetic reprogramming with global depletion of 5mC, H3K27me3 and H2A.Z, and the time at which imprint erasure is initiated and 5hmC is present. Using five alternative in vitro differentiation strategies combined with single-cell microfluidic analysis and a bona fide human cKIT(+) PGC signature, we show the stage of cKIT(+) PGC formation in the first 16 days of differentiation. Taken together, our study creates a resource of human germ line ontogeny that is essential for future studies aimed at in vitro differentiation and unveiling the mechanisms necessary to pass human DNA from one generation to the next. PMID:23242216

  2. Histochemical identification of primordial germ cells and differentiation of the gonads in homozygous tetraploid mouse embryos.

    PubMed Central

    Kaufman, M H

    1991-01-01

    This study was undertaken to establish whether primordial germ cells are differentiated by homozygous tetraploid mouse embryos produced by the technique of electrofusion, and to study the morphological features of their gonads. Tetraploid embryos were transferred to the oviducts of pseudopregnant recipients, and these were autopsied either on day 11 or days 15 or 16 of gestation. In the developmentally less advanced group, embryos in which cytogenetic analysis of their extraembryonic membranes confirmed that they had a tetraploid chromosome constitution were analysed histochemically in order to demonstrate the presence of intracellular alkaline phosphatase enzyme activity. This enabled the presence or absence of germ cells to be established. Out of a total of 9 early limb-bud stage embryos studied, all contained primordial germ cells. The latter were mostly located in association with the hindgut, though some germ cells were still present at the base of the allantois. The sex ratio in this group was close to unity. In the 2nd group in which recipients were autopsied on either day 15 or 16 of gestation, a total of 7 healthy tetraploid embryos were recovered. All displayed the characteristic craniofacial features seen in tetraploid embryos. Four of these embryos had a normal postcranial axial morphology, and their crown-rump lengths were only slightly less (81-91%) than those of developmentally matched control diploid embryos. Three of the tetraploid embryos had an abnormal postcranial axis associated with a body wall closure defect involving the anterior abdominal and lower thoracic region. In all 7 of these embryos, gonadal differentiation was consistent with their developmental age. Images Fig. 1 Fig. 2 PMID:1817135

  3. Tracking cross-contamination transfer dynamics at a mock retail deli market using GloGerm.

    PubMed

    Maitland, Jessica; Boyer, Renee; Gallagher, Dan; Duncan, Susan; Bauer, Nate; Kause, Janell; Eifert, Joseph

    2013-02-01

    Ready-to-eat (RTE) deli meats are considered a food at high risk for causing foodborne illness. Deli meats are listed as the highest risk RTE food vehicle for Listeria monocytogenes. Cross-contamination in the retail deli market may contribute to spread of pathogens to deli meats. Understanding potential cross-contamination pathways is essential for reducing the risk of contaminating various products. The objective of this study was to track cross-contamination pathways through a mock retail deli market using an abiotic surrogate, GloGerm, to visually represent how pathogens may spread through the deli environment via direct contact with food surfaces. Six contamination origination sites (slicer blade, meat chub, floor drain, preparation table, employee's glove, and employee's hands) were evaluated separately. Each site was inoculated with 20 ml of GloGerm, and a series of standard deli operations were completed (approximately 10 min of work). Photographs were then taken under UV illumination to visualize spread of GloGerm throughout the deli. A sensory panel evaluated the levels of contamination on the resulting contaminated surfaces. Five of the six contamination origination sites were associated with transfer of GloGerm to the deli case door handle, slicer blade, meat chub, preparation table, and the employee's gloves. Additional locations became contaminated (i.e., deli case shelf, prep table sink, and glove box), but this contamination was not consistent across all trials. Contamination did not spread from the floor drain to any food contact surfaces. The findings of this study reinforce the need for consistent equipment cleaning and food safety practices among deli workers to minimize cross-contamination. PMID:23433375

  4. Germs, governance, and global public health in the wake of SARS

    PubMed Central

    Fidler, David P.

    2004-01-01

    A revolution in the governance of global infectious disease threats is under way, accelerated by events triggered by the outbreak of SARS in 2003. This review article analyzes pre-SARS trends in the governance of infectious diseases, examines the impact of the SARS outbreak on these trends, and posits that germ governance is now a criterion of “good governance” in world affairs. PMID:15067309

  5. Debunking the slippery slope argument against human germ-line gene therapy.

    PubMed

    Resnik, D

    1994-02-01

    This paper attempts to debunk the slippery-slope argument against human germ-line gene therapy by showing that the downside of the slope--genetic enhancement--need not be as unethical or unjust as some people have supposed. It argues that if genetic enhancement is governed by proper regulations and is accompanied by adequate education, then it need not violate recognized principles of morality or social justice. PMID:8201288

  6. Sex Reversal in Zebrafish fancl Mutants Is Caused by Tp53-Mediated Germ Cell Apoptosis

    PubMed Central

    Rodríguez-Marí, Adriana; Cañestro, Cristian; BreMiller, Ruth A.; Nguyen-Johnson, Alexandria; Asakawa, Kazuhide; Kawakami, Koichi; Postlethwait, John H.

    2010-01-01

    The molecular genetic mechanisms of sex determination are not known for most vertebrates, including zebrafish. We identified a mutation in the zebrafish fancl gene that causes homozygous mutants to develop as fertile males due to female-to-male sex reversal. Fancl is a member of the Fanconi Anemia/BRCA DNA repair pathway. Experiments showed that zebrafish fancl was expressed in developing germ cells in bipotential gonads at the critical time of sexual fate determination. Caspase-3 immunoassays revealed increased germ cell apoptosis in fancl mutants that compromised oocyte survival. In the absence of oocytes surviving through meiosis, somatic cells of mutant gonads did not maintain expression of the ovary gene cyp19a1a and did not down-regulate expression of the early testis gene amh; consequently, gonads masculinized and became testes. Remarkably, results showed that the introduction of a tp53 (p53) mutation into fancl mutants rescued the sex-reversal phenotype by reducing germ cell apoptosis and, thus, allowed fancl mutants to become fertile females. Our results show that Fancl function is not essential for spermatogonia and oogonia to become sperm or mature oocytes, but instead suggest that Fancl function is involved in the survival of developing oocytes through meiosis. This work reveals that Tp53-mediated germ cell apoptosis induces sex reversal after the mutation of a DNA–repair pathway gene by compromising the survival of oocytes and suggests the existence of an oocyte-derived signal that biases gonad fate towards the female developmental pathway and thereby controls zebrafish sex determination. PMID:20661450

  7. Sex reversal in zebrafish fancl mutants is caused by Tp53-mediated germ cell apoptosis.

    PubMed

    Rodríguez-Marí, Adriana; Cañestro, Cristian; Bremiller, Ruth A; Nguyen-Johnson, Alexandria; Asakawa, Kazuhide; Kawakami, Koichi; Postlethwait, John H

    2010-07-01

    The molecular genetic mechanisms of sex determination are not known for most vertebrates, including zebrafish. We identified a mutation in the zebrafish fancl gene that causes homozygous mutants to develop as fertile males due to female-to-male sex reversal. Fancl is a member of the Fanconi Anemia/BRCA DNA repair pathway. Experiments showed that zebrafish fancl was expressed in developing germ cells in bipotential gonads at the critical time of sexual fate determination. Caspase-3 immunoassays revealed increased germ cell apoptosis in fancl mutants that compromised oocyte survival. In the absence of oocytes surviving through meiosis, somatic cells of mutant gonads did not maintain expression of the ovary gene cyp19a1a and did not down-regulate expression of the early testis gene amh; consequently, gonads masculinized and became testes. Remarkably, results showed that the introduction of a tp53 (p53) mutation into fancl mutants rescued the sex-reversal phenotype by reducing germ cell apoptosis and, thus, allowed fancl mutants to become fertile females. Our results show that Fancl function is not essential for spermatogonia and oogonia to become sperm or mature oocytes, but instead suggest that Fancl function is involved in the survival of developing oocytes through meiosis. This work reveals that Tp53-mediated germ cell apoptosis induces sex reversal after the mutation of a DNA-repair pathway gene by compromising the survival of oocytes and suggests the existence of an oocyte-derived signal that biases gonad fate towards the female developmental pathway and thereby controls zebrafish sex determination. PMID:20661450

  8. Melatonin ameliorates bisphenol A-induced DNA damage in the germ cells of adult male rats.

    PubMed

    Wu, Hong-Juan; Liu, Chuan; Duan, Wei-Xia; Xu, Shang-Cheng; He, Min-Di; Chen, Chun-Hai; Wang, Yan; Zhou, Zhou; Yu, Zheng-Ping; Zhang, Lei; Chen, Yu

    2013-04-15

    Bisphenol A (BPA) is a well-known endocrine-disrupting chemical (EDC) that has received particular attention because of its widespread distribution in humans. Due to its chemical similarity to diethylstilbestrol, which is carcinogenic to mammals, the possible genotoxicity of BPA has already largely been evaluated. However, the results are still inconclusive and controversial. To investigate the genotoxic effects of BPA in rat germ cells and the potential protective action of melatonin against these effects, adult male Sprague-Dawley rats were orally administered BPA at a dose of 200mg/kg body weight per day for ten consecutive days with or without melatonin pretreatment. The thiobarbituric acid reactive substances (TBARS) level and superoxide dismutase (SOD) activity in the testes were evaluated. Subsequently, their spermatocytes were isolated, and DNA damage was assessed using an alkaline comet assay and the meiotic spread method. BPA administration did not significantly affect the weights of rats and their reproductive organs, and no alteration in sperm count was found. However, we demonstrated that BPA administration induced a significant increase in TBARS levels and a decrease in SOD activity that were concomitant with an increase in DNA migration within male germ cells and ?H2AX foci formation on the autosomes of pachytene spermatocytes. Furthermore, a decrease in the proportion of 4C-cells was observed. These BPA effects were significantly alleviated by melatonin pretreatment. Nevertheless, the genotoxic effects of BPA were not accompanied by apoptosis in germ cells and morphological changes in the testes. These results indicate that BPA exposure may induce DNA damage accumulation in germ cells via oxidative stress. Moreover, melatonin may be a promising pharmacological candidate for preventing the potential genotoxicity of BPA following occupational or environmental exposure. PMID:23402883

  9. Germ-killing bush medicine P3 Emotional intelligence in the classroom P10

    E-print Network

    Liley, David

    venture puts wind beneath industry wings A new r&D centre will give AustrAliA's AircrAft component mAnufActuring the Future of Australian Manufacturing, Engineers Australia, 2009 03 Bush meDicine for A germ-killing, he inDustry Access to improveD mAnufActuring techniques AnD ADvAnceD mAteriAls david horwood mAnufActuring

  10. Glycolytic enzymes localize to ribonucleoprotein granules in Drosophila germ cells, bind Tudor and protect from transposable elements.

    PubMed

    Gao, Ming; Thomson, Travis C; Creed, T Michael; Tu, Shikui; Loganathan, Sudan N; Jackson, Christina A; McCluskey, Patrick; Lin, Yanyan; Collier, Scott E; Weng, Zhiping; Lasko, Paul; Ohi, Melanie D; Arkov, Alexey L

    2015-03-01

    Germ cells give rise to all cell lineages in the next-generation and are responsible for the continuity of life. In a variety of organisms, germ cells and stem cells contain large ribonucleoprotein granules. Although these particles were discovered more than 100 years ago, their assembly and functions are not well understood. Here we report that glycolytic enzymes are components of these granules in Drosophila germ cells and both their mRNAs and the enzymes themselves are enriched in germ cells. We show that these enzymes are specifically required for germ cell development and that they protect their genomes from transposable elements, providing the first link between metabolism and transposon silencing. We further demonstrate that in the granules, glycolytic enzymes associate with the evolutionarily conserved Tudor protein. Our biochemical and single-particle EM structural analyses of purified Tudor show a flexible molecule and suggest a mechanism for the recruitment of glycolytic enzymes to the granules. Our data indicate that germ cells, similarly to stem cells and tumor cells, might prefer to produce energy through the glycolytic pathway, thus linking a particular metabolism to pluripotency. PMID:25600116

  11. Primary production off Southern California relative to surface layer carbon budgets: A component of the California Basins Study, CaBS. Final report, [1 June 1989--14 November 1991

    SciTech Connect

    Trees, C.C.

    1994-04-22

    This study started on 1 June 1989 and ended 14 November 1991. Two moored in situ natural fluorometers were deployed in January 1990 to collect bio-optical data for one year, making ground truth measurements around the mooring during 4 cruises. This one-year time series would investigate how the short-term physical forcing aliases the long-term primary production record such that the apparent, larger interannual variability in the record is in reality ``noise`` due to short-term fluctuations in the rate of nutrient input to the euphotic zone. These continuous measurements from moored bio-optical instruments would also allow better estimates of the mean and variance in primary production in these waters than has previously been available from shipboard measurements, as well as, phytoplankton response to short-term physical events. Ancillary measurements that were made were: (1) characterization of the apparent and inherent optical properties, (2) photosynthetic pigment distributions using both HPLC and standard fluorometric methods, (3) carbon, hydrogen and nitrogen content of suspended particulate matter, (4) primary production using conventional {sup 14}C methods from simulated in situ experiments.

  12. SNP-based prediction of the human germ cell methylation landscape.

    PubMed

    Xie, Hehuang; Wang, Min; Bischof, Jared; Bonaldo, Maria de Fatima; Soares, Marcelo Bento

    2009-05-01

    Base substitution occurs at a high rate at CpG dinucleotides due to the frequent methylation of CpG and the deamination of methylated cytosine to thymine. If these substitutions occur in germ cells, they constitute a heritable mutation that may eventually rise to polymorphic frequencies, hence resulting in a SNP that is methylation associated. In this study, we sought to identify clusters of methylation associated SNPs as a basis for prediction of methylation landscapes of germ cell genomes. Genomic regions enriched with methylation associated SNPs, namely "methylation associated SNP clusters", were identified with an agglomerative hierarchical clustering algorithm. Repetitive elements, segmental duplications, and syntenic tandem DNA repeats were enriched in methylation associated SNP clusters. The frequency of methylation associated SNPs in Alu Y/S elements exhibited a gradient pattern suggestive of linear spreading, being higher in proximity to methylation associated SNP clusters and lower closer to CpG islands. Interestingly, methylation associated SNP clusters were over-represented near the transcriptional initiation sites of immune response genes. We propose a de novo DNA methylation model during germ cell development whereby a pattern is established by long-range chromatic interactions through syntenic repeats combined with regional methylation spreading from methylation associated SNP clusters. PMID:19442638

  13. Carotenoids of aleurone, germ, and endosperm fractions of barley, corn and wheat differentially inhibit oxidative stress.

    PubMed

    Masisi, Kabo; Diehl-Jones, William L; Gordon, Joseph; Chapman, Donald; Moghadasian, Mohammed H; Beta, Trust

    2015-03-18

    The antioxidant potential of carotenoids from aleurone, germ, and endosperm fractions of barley, corn, and wheat has been evaluated. HPLC analysis confirmed the presence of lutein and zeaxanthin carotenoids (nd-15139 ?g/kg) in extracts of cereal grain fractions. The antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl, oxygen radical absorbance capacity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays revealed significantly higher (P<0.001) antioxidant activity in the germ than in the aleurone and endosperm fractions. Using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, 2,2'azobis (2-amidinopropane)dihydrochloride (AAPH)-induced cell loss was effectively reduced by preincubating Caco-2, HT-29, and FHs 74 Int cells with carotenoid extracts. Moreover, carotenoid extracts reduced (P<0.001) AAPH-induced intracellular oxidation in the cell lines, suggesting antioxidant activity. Of the 84 antioxidant pathway genes included in microarray array analysis (HT-29 cells), the expressions of 28 genes were enhanced (P<0.05). Our findings suggest that carotenoids of germ, aleurone, and endosperm fractions improved antioxidant capacity and thus have the potential to mitigate oxidative stress. PMID:25706713

  14. Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish.

    PubMed

    Wildner, Daniel Dantas; Grier, Harry; Quagio-Grassiotto, Irani

    2013-03-01

    The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event. PMID:23317762

  15. The majority of early primordial germ cells acquire pluripotency by AKT activation.

    PubMed

    Matsui, Yasuhisa; Takehara, Asuka; Tokitake, Yuko; Ikeda, Makiko; Obara, Yuka; Morita-Fujimura, Yuiko; Kimura, Tohru; Nakano, Toru

    2014-12-01

    Primordial germ cells (PGCs) are undifferentiated germ cells in embryos, the fate of which is to become gametes; however, mouse PGCs can easily be reprogrammed into pluripotent embryonic germ cells (EGCs) in culture in the presence of particular extracellular factors, such as combinations of Steel factor (KITL), LIF and bFGF (FGF2). Early PGCs form EGCs more readily than do later PGCs, and PGCs lose the ability to form EGCs by embryonic day (E) 15.5. Here, we examined the effects of activation of the serine/threonine kinase AKT in PGCs during EGC formation; notably, AKT activation, in combination with LIF and bFGF, enhanced EGC formation and caused ?60% of E10.5 PGCs to become EGCs. The results indicate that the majority of PGCs at E10.5 could acquire pluripotency with an activated AKT signaling pathway. Importantly, AKT activation did not fully substitute for bFGF and LIF, and AKT activation without both LIF and bFGF did not result in EGC formation. These findings indicate that AKT signal enhances and/or collaborates with signaling pathways of bFGF and of LIF in PGCs for the acquisition of pluripotency. PMID:25359722

  16. Xist imprinting is promoted by the hemizygous (unpaired) state in the male germ line.

    PubMed

    Sun, Sha; Payer, Bernhard; Namekawa, Satoshi; An, Jee Young; Press, William; Catalan-Dibene, Jovani; Sunwoo, Hongjae; Lee, Jeannie T

    2015-11-24

    The long noncoding X-inactivation-specific transcript (Xist gene) is responsible for mammalian X-chromosome dosage compensation between the sexes, the process by which one of the two X chromosomes is inactivated in the female soma. Xist is essential for both the random and imprinted forms of X-chromosome inactivation. In the imprinted form, Xist is paternally marked to be expressed in female embryos. To investigate the mechanism of Xist imprinting, we introduce Xist transgenes (Tg) into the male germ line. Although ectopic high-level Xist expression on autosomes can be compatible with viability, transgenic animals demonstrate reduced fitness, subfertility, defective meiotic pairing, and other germ-cell abnormalities. In the progeny, paternal-specific expression is recapitulated by the 200-kb Xist Tg. However, Xist imprinting occurs efficiently only when it is in an unpaired or unpartnered state during male meiosis. When transmitted from a hemizygous father (+/Tg), the Xist Tg demonstrates paternal-specific expression in the early embryo. When transmitted by a homozygous father (Tg/Tg), the Tg fails to show imprinted expression. Thus, Xist imprinting is directed by sequences within a 200-kb X-linked region, and the hemizygous (unpaired) state of the Xist region promotes its imprinting in the male germ line. PMID:26489649

  17. Epoxides Derived from Dietary Dihomo-Gamma-Linolenic Acid Induce Germ Cell Death in C. elegans.

    PubMed

    Deline, Marshall; Keller, Julia; Rothe, Michael; Schunck, Wolf-Hagen; Menzel, Ralph; Watts, Jennifer L

    2015-01-01

    Dietary fats are not created equally, slight differences in structure lead to crucial differences in function. Muticellular organisms use polyunsaturated fatty acid as substrates to produce potent signaling molecules crucial for many physiological processes, including reproduction. Here we explored the mechanism responsible for germ cell loss induced by dietary supplementation of dihomo-gamma-linolenic acid (DGLA, 20:3n-6) in the roundworm Caenorhabditis elegans. In this study we found that C. elegans CYP-33E2 activity produces a range of epoxy and hydroxy metabolites from dietary DGLA. Knockdown of cyp-33E2 suppressed the DGLA-induced sterility phenotype. Additionally, direct exposure of two specific DGLA-derived epoxy products, 8,9- and 14,15-epoxyeicosadienoic acids, produced germ cell abnormalities in the C. elegans gonad. We propose that sterility is mediated by the production of toxic DGLA-derived epoxides that trigger germ cell destruction. These studies are the first to establish a biological activity for a CYP-produced metabolite of DGLA. PMID:26486965

  18. Production of human CD59-transgenic pigs by embryonic germ cell nuclear transfer

    SciTech Connect

    Ahn, Kwang Sung; Won, Ji Young; Park, Jin-Ki; Sorrell, Alice M.; Heo, Soon Young; Kang, Jee Hyun; Woo, Jae-Seok; Choi, Bong-Hwan; Chang, Won-Kyong; Shim, Hosup; Institute of Tissue Regeneration Engineering, Dankook University, Cheonan

    2010-10-01

    Research highlights: {yields} Human CD59 (hCD59) gene was introduced into porcine embryonic germ (EG) cells. {yields} hCD59-transgenic EG cells were resistant to hyperacute rejection in cytolytic assay. {yields} hCD59-transgenic pigs were produced by EG cell nuclear transfer. -- Abstract: This study was performed to produce transgenic pigs expressing the human complement regulatory protein CD59 (hCD59) using the nuclear transfer (NT) of embryonic germ (EG) cells, which are undifferentiated stem cells derived from primordial germ cells. Because EG cells can be cultured indefinitely in an undifferentiated state, they may provide an inexhaustible source of nuclear donor cells for NT to produce transgenic pigs. A total of 1980 NT embryos derived from hCD59-transgenic EG cells were transferred to ten recipients, resulting in the birth of fifteen piglets from three pregnancies. Among these offspring, ten were alive without overt health problems. Based on PCR analysis, all fifteen piglets were confirmed as hCD59 transgenic. The expression of the hCD59 transgene in the ten living piglets was verified by RT-PCR. Western analysis showed the expression of the hCD59 protein in four of the ten RT-PCR-positive piglets. These results demonstrate that hCD59-transgenic pigs could effectively be produced by EG cell NT and that such transgenic pigs may be used as organ donors in pig-to-human xenotransplantation.

  19. RNA Binding Protein Ptbp2 Is Essential for Male Germ Cell Development.

    PubMed

    Zagore, Leah L; Grabinski, Sarah E; Sweet, Thomas J; Hannigan, Molly M; Sramkoski, R Michael; Li, Qin; Licatalosi, Donny D

    2015-12-01

    RNA binding proteins (RBPs) are increasingly recognized as essential factors in tissue development and homeostasis. The polypyrimidine tract binding (PTB) protein family of RBPs are important posttranscriptional regulators of gene expression. In the nervous system, the function and importance of PTB protein 2 (Ptbp2) as a key alternative splicing regulator is well established. Ptbp2 is also abundantly expressed during spermatogenesis, but its role in this developmental program has not been explored. Additionally, the importance of alternative splicing regulation in spermatogenesis is unclear. Here, we demonstrate that Ptbp2 is essential for spermatogenesis. We also describe an improved dual fluorescence flow cytometry strategy to discriminate, quantify, and collect germ cells in different stages of development. Using this approach, in combination with traditional histological methods, we show that Ptbp2 ablation results in germ cell loss due to increased apoptosis of meiotic spermatocytes and postmeiotic arrest of spermatid differentiation. Furthermore, we show that Ptbp2 is required for alternative splicing regulation in the testis, as in brain. Strikingly, not all of the alternatively spliced RNAs examined were sensitive to Ptbp2 loss in both tissues. Collectively, the data provide evidence for an important role for alternative splicing regulation in germ cell development and a central role for Ptbp2 in this process. PMID:26391954

  20. Genomic analysis of germ line and somatic variants in familial myelodysplasia/acute myeloid leukemia.

    PubMed

    Churpek, Jane E; Pyrtel, Khateriaa; Kanchi, Krishna-Latha; Shao, Jin; Koboldt, Daniel; Miller, Christopher A; Shen, Dong; Fulton, Robert; O'Laughlin, Michelle; Fronick, Catrina; Pusic, Iskra; Uy, Geoffrey L; Braunstein, Evan M; Levis, Mark; Ross, Julie; Elliott, Kevin; Heath, Sharon; Jiang, Allan; Westervelt, Peter; DiPersio, John F; Link, Daniel C; Walter, Matthew J; Welch, John; Wilson, Richard; Ley, Timothy J; Godley, Lucy A; Graubert, Timothy A

    2015-11-26

    Familial clustering of myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) can be caused by inherited factors. We screened 59 individuals from 17 families with 2 or more biological relatives with MDS/AML for variants in 12 genes with established roles in predisposition to MDS/AML, and identified a pathogenic germ line variant in 5 families (29%). Extending the screen with a panel of 264 genes that are recurrently mutated in de novo AML, we identified rare, nonsynonymous germ line variants in 4 genes, each segregating with MDS/AML in 2 families. Somatic mutations are required for progression to MDS/AML in these familial cases. Using a combination of targeted and exome sequencing of tumor and matched normal samples from 26 familial MDS/AML cases and asymptomatic carriers, we identified recurrent frameshift mutations in the cohesin-associated factor PDS5B, co-occurrence of somatic ASXL1 mutations with germ line GATA2 mutations, and recurrent mutations in other known MDS/AML drivers. Mutations in genes that are recurrently mutated in de novo AML were underrepresented in the familial MDS/AML cases, although the total number of somatic mutations per exome was the same. Lastly, clonal skewing of hematopoiesis was detected in 67% of young, asymptomatic RUNX1 carriers, providing a potential biomarker that could be used for surveillance in these high-risk families. PMID:26492932

  1. Isolation of male germ-line stem cells; influence of GDNF

    PubMed Central

    Hofmann, Marie-Claude; Braydich-Stolle, Laura; Dym, Martin

    2010-01-01

    The identification and physical isolation of testis stem cells, a subset of type A spermatogonia, is critical to our understanding of their growth regulation during the first steps of spermatogenesis. These stem cells remain poorly characterized because of the paucity of specific molecular markers that permit us to distinguish them from other germ cells. Thus, the molecular mechanisms driving the first steps of spermatogenesis are still unknown. We show in the present study that GFR?-1, the receptor for GDNF (glial cell line-derived neurotrophic factor), is strongly expressed by a subset of type A spermatogonia in the basal part of the seminiferous epithelium. Using this characteristic, we devised a method to specifically isolate these GFR?-1-positive cells from immature mouse testes. The isolated cells express Ret, a tyrosine kinase transmembrane receptor that mediates the intracellular response to GDNF via GFR?-1. After stimulation with rGDNF, the isolated cells proliferated in culture and underwent the first steps of germ cell differentiation. Microarray analysis revealed that GDNF induces the differential expression of a total of 1124 genes. Among the genes upregulated by GDNF were many genes involved in early mammalian development, differentiation, and the cell cycle. This report describes the first isolation of a pure population of GFR?-1-positive cells in the testis and identifies signaling pathways that may play a crucial role in maintaining germ-line stem cell proliferation and/or renewal. PMID:15708562

  2. Analysis of Medaka sox9 Orthologue Reveals a Conserved Role in Germ Cell Maintenance

    PubMed Central

    Nakamura, Shuhei; Watakabe, Ikuko; Nishimura, Toshiya; Toyoda, Atsushi; Taniguchi, Yoshihito; Tanaka, Minoru

    2012-01-01

    The sex determining gene is divergent among different animal species. However, sox9 is up-regulated in the male gonads in a number of species in which it is the essential regulator of testis determination. It is therefore often discussed that the sex determining gene-sox9 axis functions in several vertebrates. In our current study, we show that sox9b in the medaka (Oryzias latipes) is one of the orthologues of mammalian Sox9 at syntenic and expression levels. Medaka sox9b affects the organization of extracellular matrices, which represents a conserved role of sox9, but does not directly regulate testis determination. We made this determination via gene expression and phenotype analyses of medaka with different copy numbers of sox9b. Sox9b is involved in promoting cellular associations and is indispensible for the proper proliferation and survival of germ cells in both female and male medaka gonads. Medaka mutants that lack sox9b function exhibit a seemingly paradoxical phenotype of sex reversal to male. This is explained by a reduction in the germ cell number associated with aberrant extracellular matrices. Together with its identified roles in other vertebrate gonads, a testis-determining role for Sox9 in mammals is likely to have been neofunctionalized and appended to its conserved role in germ cell maintenance. PMID:22253846

  3. Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

    PubMed Central

    Lee, Sang-Kon; Park, Sungman; Gimm, Yoon-Myoung; Kim, Yoon-Won

    2014-01-01

    The energy generated by an extremely low frequency electromagnetic field (ELF-EMF) is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF) is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010) for limiting exposure to time-varying MF (1?Hz to 100?kHz), overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF. PMID:25025060

  4. Epoxides Derived from Dietary Dihomo-Gamma-Linolenic Acid Induce Germ Cell Death in C. elegans

    PubMed Central

    Deline, Marshall; Keller, Julia; Rothe, Michael; Schunck, Wolf-Hagen; Menzel, Ralph; Watts, Jennifer L.

    2015-01-01

    Dietary fats are not created equally, slight differences in structure lead to crucial differences in function. Muticellular organisms use polyunsaturated fatty acid as substrates to produce potent signaling molecules crucial for many physiological processes, including reproduction. Here we explored the mechanism responsible for germ cell loss induced by dietary supplementation of dihomo-gamma-linolenic acid (DGLA, 20:3n-6) in the roundworm Caenorhabditis elegans. In this study we found that C. elegans CYP-33E2 activity produces a range of epoxy and hydroxy metabolites from dietary DGLA. Knockdown of cyp-33E2 suppressed the DGLA-induced sterility phenotype. Additionally, direct exposure of two specific DGLA-derived epoxy products, 8,9- and 14,15-epoxyeicosadienoic acids, produced germ cell abnormalities in the C. elegans gonad. We propose that sterility is mediated by the production of toxic DGLA-derived epoxides that trigger germ cell destruction. These studies are the first to establish a biological activity for a CYP-produced metabolite of DGLA. PMID:26486965

  5. Primary Hepatocytes in Sandwich Culture.

    PubMed

    Keemink, Janneke; Oorts, Marlies; Annaert, Pieter

    2015-01-01

    Hepatocytes in sandwich configuration constitute of primary hepatocytes cultured between two layers of extracellular matrix. Sandwich-cultured hepatocytes maintain expression of liver-specific proteins and gradually form intact bile canaliculi with functional biliary excretion of endogenous compounds and xenobiotics. Both freshly isolated and cryopreserved hepatocytes can be used to establish sandwich cultures. Therefore, this preclinical model has become an invaluable in vitro tool to evaluate hepatobiliary drug transport, metabolism, hepatotoxicity, and drug interactions. In this chapter, commonly used procedures to cultivate primary hepatocytes from human and rat in sandwich configuration are described. PMID:26272142

  6. Loss of Gata4 in Sertoli cells impairs the spermatogonial stem cell niche and causes germ cell exhaustion by attenuating chemokine signaling.

    PubMed

    Chen, Su-Ren; Tang, Ji-Xin; Cheng, Jin-Mei; Li, Jian; Jin, Cheng; Li, Xiao-Yu; Deng, Shou-Long; Zhang, Yan; Wang, Xiu-Xia; Liu, Yi-Xun

    2015-11-10

    Sertoli cells, the primary somatic cell in the seminiferous epithelium, provide the spermatogonial stem cell (SSC) microenvironment (niche) through physical support and the expression of paracrine factors. However, the regulatory mechanisms within the SSC niche, which is primarily controlled by Sertoli cells, remain largely unknown. GATA4 is a Sertoli cell marker, involved in genital ridge initiation, sex determination and differentiation during the embryonic stage. Here, we showed that neonatal mice with a targeted disruption of Gata4 in Sertoli cells (Gata4flox/flox; Amh-Cre; hereafter termed Gata4 cKO) displayed a loss of the establishment and maintenance of the SSC pool and apoptosis of both gonocyte-derived differentiating spermatogonia and meiotic spermatocytes. Thus, progressive germ cell depletion and a Sertoli-cell-only syndrome were observed as early as the first wave of murine spermatogenesis. Transplantation of germ cells from postnatal day 5 (P5) Gata4 cKO mice into KitW/W-v recipient seminiferous tubules restored spermatogenesis. In addition, microarray analyses of P5 Gata4 cKO mouse testes showed alterations in chemokine signaling factors, including Cxcl12, Ccl3, Cxcr4 (CXCL12 receptor), Ccr1 (CCL3 receptor), Ccl9, Xcl1 and Ccrl2. Deletion of Gata4 in Sertoli cells markedly attenuated Sertoli cell chemotaxis, which guides SSCs or prospermatogonia to the stem cell niche. Finally, we showed that GATA4 transcriptionally regulated Cxcl12 and Ccl9, and the addition of CXCL12 and CCL9 to an in vitro testis tissue culture system increased the number of PLZF+ undifferentiated spermatogonia within Gata4 cKO testes. Together, these results reveal a novel role for GATA4 in controlling the SSC niche via the transcriptional regulation of chemokine signaling shortly after birth. PMID:26473289

  7. Treatment Outcomes, Growth Height, and Neuroendocrine Functions in Patients With Intracranial Germ Cell Tumors Treated With Chemoradiation Therapy

    SciTech Connect

    Odagiri, Kazumasa; Department of Radiology, Kanagawa Children's Medical Center, Yokohama ; Omura, Motoko; Department of Radiology, Kanagawa Children's Medical Center, Yokohama ; Hata, Masaharu; Aida, Noriko; Niwa, Tetsu; Ogino, Ichiro; Kigasawa, Hisato; Adachi, Masataka; Inoue, Tomio

    2012-11-01

    Purpose: We carried out a retrospective review of patients receiving chemoradiation therapy (CRT) for intracranial germ cell tumor (GCT) using a lower dose than those previously reported. To identify an optimal GCT treatment strategy, we evaluated treatment outcomes, growth height, and neuroendocrine functions. Methods and Materials: Twenty-two patients with GCT, including 4 patients with nongerminomatous GCT (NGGCT) were treated with CRT. The median age at initial diagnosis was 11.5 years (range, 6-19 years). Seventeen patients initially received whole brain irradiation (median dose, 19.8 Gy), and 5 patients, including 4 with NGGCT, received craniospinal irradiation (median dose, 30.6 Gy). The median radiation doses delivered to the primary site were 36 Gy for pure germinoma and 45 Gy for NGGCT. Seventeen patients had tumors adjacent to the hypothalamic-pituitary axis (HPA), and 5 had tumors away from the HPA. Results: The median follow-up time was 72 months (range, 18-203 months). The rates of both disease-free survival and overall survival were 100%. The standard deviation scores (SDSs) of final heights recorded at the last assessment tended to be lower than those at initial diagnosis. Even in all 5 patients with tumors located away from the HPA, final height SDSs decreased (p = 0.018). In 16 patients with tumors adjacent to the HPA, 8 showed metabolic changes suggestive of hypothalamic obesity and/or growth hormone deficiency, and 13 had other pituitary hormone deficiencies. In contrast, 4 of 5 patients with tumors away from the HPA did not show any neuroendocrine dysfunctions except for a tendency to short stature. Conclusions: CRT for GCT using limited radiation doses resulted in excellent treatment outcomes. Even after limited radiation doses, insufficient growth height was often observed that was independent of tumor location. Our study suggests that close follow-up of neuroendocrine functions, including growth hormone, is essential for all patients with GCT.

  8. Layered materials

    NASA Astrophysics Data System (ADS)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and an overview of current areas of research interest.

  9. Crosstalk between endoplasmic reticulum stress and mitochondrial pathway mediates cadmium-induced germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Hua; Zhao, Xian-Feng; Wang, Qun; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2011-12-01

    Cadmium (Cd) is associated with male infertility and poor semen quality in humans. Increasing evidence demonstrates that Cd induces testicular germ cell apoptosis in rodent animals. However, the molecular mechanisms of Cd-induced testicular germ cell apoptosis remain poorly understood. In the present study, we investigated the role of endoplasmic reticulum (ER) stress on Cd-evoked germ cell apoptosis in testes. We show that spliced form of XBP-1, the target of the IRE1 pathway, was significantly increased in testes of mice injected with CdCl(2). GRP78, an ER chaperone, and CHOP, a downstream target of the PERK pathway, were upregulated in testes of Cd-treated mice. In addition, acute Cd exposure significantly caused eIF2? and JNK phosphorylation in testes, indicating that the unfolded protein response pathway in testes was activated by Cd. Interestingly, phenylbutyric acid (PBA), an ER chemical chaperone, attenuated Cd-induced ER stress and protected against germ cell apoptosis in testes. In addition, PBA significantly attenuated Cd-evoked release of cytochrome c from mitochondria to cytoplasm in testes. Taken together, these results suggest that crosstalk between ER stress signaling and mitochondrial pathway mediates Cd-induced testicular germ cell apoptosis. PMID:21908765

  10. Co-culture of Mouse Embryonic Stem Cells with Sertoli Cells Promote in vitro Generation of Germ Cells

    PubMed Central

    Miryounesi, Mohammad; Nayernia, Karim; Dianatpour, Mahdi; Mansouri, Fatemeh; Modarressi, Mohammad Hossein

    2013-01-01

    Objective(s): Sertoli cells support in vivo germ cell production; but, its exact mechanism has not been well understood. The present study was designed to analyze the effect of Sertoli cells in differentiation of mouse embryonic stem cells (mESCs) to germ cells. Materials and Methods: A fusion construct composed of a Stra8 gene promoter and the coding region of enhanced green fluorescence protein was produced to select differentiated mESCs. To analyze sertoli cells’ effect in differentiation process, mESCs were separated into two groups: the first group was cultured on gelatin with retinoic acid treatment and the second group was co-cultured with sertoli cell feeder without retinoic acid induction. Expressions of pre-meiotic (Stra8), meiotic (Dazl and Sycp3) and post-meiotic (Prm1) genes were evaluated at different differentiation stages (+7, +12 and +18 days of culture). Results: In the first group, expressions of meiotic and post-meiotic genes started 12 and 18 days after induction with retinoic acid, respectively. In the second group, 7 days after co-culturing with Sertoli cells, expression of meiotic and post-meiotic genes was observed. Conclusion: These results show that differentiation process to germ cells is supported by Sertoli cells. Our findings provide a novel effective approach for generation of germ cell in vitro and studying the interaction of germ cells with their niche. PMID:23997904

  11. On the role of germ cells in mammalian gonad development: quiet passengers or back-seat drivers?

    PubMed

    Rios-Rojas, Clarissa; Bowles, Josephine; Koopman, Peter

    2015-04-01

    In addition to their role as endocrine organs, the gonads nurture and protect germ cells, and regulate the formation of gametes competent to convey the genome to the following generation. After sex determination, gonadal somatic cells use several known signalling pathways to direct germ cell development. However, the extent to which germ cells communicate back to the soma, the molecular signals they use to do so and the significance of any such signalling remain as open questions. Herein, we review findings arising from the study of gonadal development and function in the absence of germ cells in a range of organisms. Most published studies support the view that germ cells are unimportant for foetal gonadal development in mammals, but later become critical for stabilisation of gonadal function and somatic cell phenotype. However, the lack of consistency in the data, and clear differences between mammals and other vertebrates and invertebrates, suggests that the story may not be so simple and would benefit from more careful analysis using contemporary molecular, cell biology and imaging tools. PMID:25628441

  12. A gene family required for human germ cell development evolved from an ancient meiotic gene conserved in metazoans

    PubMed Central

    Xu, Eugene Yujun; Moore, Frederick L.; Pera, Renee A. Reijo

    2001-01-01

    The Deleted in AZoospermia (DAZ) genes encode potential RNA-binding proteins that are expressed exclusively in prenatal and postnatal germ cells and are strong candidates for human fertility factors. Here we report the identification of an additional member of the DAZ gene family, which we have called BOULE. With the identification of this gene, it is clear that the human DAZ gene family contains at least three members: DAZ, a Y-chromosome gene cluster that arose 30–40 million years ago and whose deletion is linked to infertility in men; DAZL, the “father” of DAZ, a gene that maps to human chromosome 3 and has homologs required for both female and male germ cell development in other organisms; and BOULE, a gene that we propose is the “grandfather” of DAZ and maps to human chromosome 2. Human and mouse BOULE resemble the invertebrate meiotic regulator Boule, the proposed ortholog of DAZ, in sequence and expression pattern and hence likely perform a similar meiotic function. In contrast, the previously identified human DAZ and DAZL are expressed much earlier than BOULE in prenatal germ stem cells and spermatogonia; DAZL also is expressed in female germ cells. These data suggest that homologs of the DAZ gene family can be grouped into two subfamilies (BOULE and DAZL) and that members of the DAZ family evolved from an ancestral meiotic regulator, Boule, to assume distinct, yet overlapping, functions in germ cell development. PMID:11390979

  13. Large, male germ cell-specific hypomethylated DNA domains with unique genomic and epigenomic features on the mouse X chromosome.

    PubMed

    Ikeda, Rieko; Shiura, Hirosuke; Numata, Koji; Sugimoto, Michihiko; Kondo, Masayo; Mise, Nathan; Suzuki, Masako; Greally, John M; Abe, Kuniya

    2013-12-01

    To understand the epigenetic regulation required for germ cell-specific gene expression in the mouse, we analysed DNA methylation profiles of developing germ cells using a microarray-based assay adapted for a small number of cells. The analysis revealed differentially methylated sites between cell types tested. Here, we focused on a group of genomic sequences hypomethylated specifically in germline cells as candidate regions involved in the epigenetic regulation of germline gene expression. These hypomethylated sequences tend to be clustered, forming large (10 kb to ~9 Mb) genomic domains, particularly on the X chromosome of male germ cells. Most of these regions, designated here as large hypomethylated domains (LoDs), correspond to segmentally duplicated regions that contain gene families showing germ cell- or testis-specific expression, including cancer testis antigen genes. We found an inverse correlation between DNA methylation level and expression of genes in these domains. Most LoDs appear to be enriched with H3 lysine 9 dimethylation, usually regarded as a repressive histone modification, although some LoD genes can be expressed in male germ cells. It thus appears that such a unique epigenomic state associated with the LoDs may constitute a basis for the specific expression of genes contained in these genomic domains. PMID:23861320

  14. Effect of the solvent type and temperature on phytosterol contents and compositions of wheat straw, bran, and germ extracts.

    PubMed

    Dunford, Nurhan Turgut; Irmak, Sibel; Jonnala, Ramakanth

    2009-11-25

    Wheat fractions, such as bran, germ, and straw, are rich in a number of health beneficial bioactive compounds. However, they have not been exploited to their full capacity for value-added product development. This study examines the potential of recovering phytosterol (PS)-enriched extracts from wheat germ, bran, and straw. The main objective of the study was to evaluate the effect of solvent type and temperature on PS content and composition in straw, bran, and germ extracts. Petroleum ether, chloroform, n-hexane, and ethanol were used as solvents. A pressurized solvent extraction system was used for extraction of wheat fractions. Germ extracts had the highest total PS content followed by straw and bran extracts. Beta-sitosterol, campesterol, and stigmasterol were the main PSs in all of the extracts. Ethanol extraction resulted in the lowest total PS recovery from germ. Solvent type had a significant effect on PS composition in straw extracts. beta-Sitosterol was the most abundant PS in straw hexane extracts (74% of total PS). Petroleum ether, chloroform, and ethanol extracted more stigmasterol than beta-sitosterol from straw. This study demonstrated that the solvent type and temperature had significant effects on both PS content and composition of extracts collected from wheat fractions. Because of the complex nature of the agricultural materials, solvent selection and process optimization need to be based on experimental data. Pressurized solvent extraction is a useful technique to screen complex biological materials for their composition and to determine processing conditions to be optimized. PMID:19848388

  15. Epigenetic Regulation of Oogenesis and Germ Stem Cell Maintenance by the Drosophila Histone Methyltransferase Eggless/dSetDB1

    PubMed Central

    Clough, Emily; Tedeschi, Thomas; Hazelrigg, Tulle

    2015-01-01

    The Drosophila melanogaster histone lysine methyltransferase (HKMT) Eggless (Egg/dSETDB1) catalyzes methylation of Histone H3 lysine 9 (H3K9), a signature of repressive heterochromatin. Our previous studies showed that H3K9 methylation by Egg is required for oogenesis. Here we analyze a set of EMS-induced mutations in the egg gene, identify the molecular lesions of these mutations, and compare the effects on oogenesis of both strong loss-of-function and weak hypomorphic alleles. These studies show that H3K9 methylation by Egg is required for multiple stages of oogenesis. Mosaic expression experiments show that the egg gene is not required intrinsically in the germ cells for their early differentiation, but is required in the germ cells for their survival past stage 5 of oogenesis. egg is also required in germ stem cells for their maintenance, since egg? germ stem cells initially survive but are not maintained as females age. Mosaic analysis also reveals that the early egg chamber budding defects in egg? ovaries are due to an intrinsic requirement for egg in follicle stem cells and their descendents, and that egg plays a non-autonomous role in somatic cells in the germarium to influence the differentiation of early germ cells. PMID:24485852

  16. Proliferation of endogenous retroviruses in the early stages of a host germ line invasion.

    PubMed

    Ishida, Yasuko; Zhao, Kai; Greenwood, Alex D; Roca, Alfred L

    2015-01-01

    Endogenous retroviruses (ERVs) comprise 8% of the human genome and are common in all vertebrate genomes. The only retrovirus known to be currently transitioning from exogenous to endogenous form is the koala retrovirus (KoRV), making koalas (Phascolarctos cinereus) ideal for examining the early stages of retroviral endogenization. To distinguish endogenous from exogenous KoRV proviruses, we isolated koala genomic regions flanking KoRV integration sites. In three wild southern Australian koalas, there were fewer KoRV loci than in three captive Queensland koalas, consistent with reports that southern Australian koalas carry fewer KoRVs. Of 39 distinct KoRV proviral loci examined in a sire-dam-progeny triad, all proved to be vertically transmitted and endogenous; none was exogenous. Of the 39 endogenous KoRVs (enKoRVs), only one was present in the genomes of both the sire and the dam, suggesting that, at this early stage in the retroviral invasion of a host germ line, very large numbers of ERVs have proliferated at very low frequencies in the koala population. Sequence divergence between the 5'- and 3'-long terminal repeats (LTRs) of a provirus can be used as a molecular clock. Within each of ten enKoRVs, the 5'-LTR sequence was identical to the 3'-LTR sequence, suggesting a maximum age for enKoRV invasion of the koala germ line of approximately 22,200-49,900 years ago, although a much younger age is possible. Across the ten proviruses, seven LTR haplotypes were detected, indicating that at least seven different retroviral sequences had entered the koala germ line. PMID:25261407

  17. Delayed Effects of Whole Brain Radiotherapy in Germ Cell Tumor Patients With Central Nervous System Metastases

    SciTech Connect

    Doyle, Danielle M. Einhorn, Lawrence H.

    2008-04-01

    Purpose: Central nervous system (CNS) metastases are uncommon in patients with germ cell tumors, with an incidence of 2-3%. CNS metastases have been managed with whole brain radiotherapy (WBRT) and concomitant cisplatin-based combination chemotherapy. Our previous study did not observe serious CNS toxicity (Int J Radiat Oncol Biol Phys 1991;22:17-22). We now report on 5 patients who developed delayed significant CNS toxicity. Patients and Methods: We observed 5 patients with delayed CNS toxicity. The initial diagnosis was between 1981 and 2003. All patients had poor-risk disease according to the International Germ Cell Consensus Collaborative Group criteria. Of the 5 patients, 3 had CNS metastases at diagnosis and 2 developed relapses with CNS metastases. These 5 patients underwent WBRT to 4,000-5,000 cGy in 18-28 fractions concurrently with cisplatin-based chemotherapy. Results: All 5 patients developed delayed symptoms consistent with progressive multifocal leukoencephalopathy. The symptoms included seizures, hemiparesis, cranial neuropathy, headaches, blindness, dementia, and ataxia. The median time from WBRT to CNS symptoms was 72 months (range, 9-228). Head imaging revealed multiple abnormalities consistent with gliosis and diffuse cerebral atrophy. Of the 5 patients, 3 had progressive and 2 stable symptoms. Treatment with surgery and/or steroids had modest benefit. The progressive multifocal leukoencephalopathy resulted in significant debility in all 5 patients, resulting in death (3 patients), loss of work, steroid-induced morbidity, and recurrent hospitalizations. Conclusion: Whole brain radiotherapy is not innocuous in young patients with germ cell tumors and can cause late CNS toxicity.

  18. Germ-line activation of the luteinizing hormone receptor directly drives spermiogenesis in a nonmammalian vertebrate.

    PubMed

    Chauvigné, François; Zapater, Cinta; Gasol, Josep M; Cerdà, Joan

    2014-01-28

    In both mammals and teleosts, the differentiation of postmeiotic spermatids to spermatozoa (spermiogenesis) is thought to be indirectly controlled by the luteinizing hormone (LH) acting through the LH/choriogonadotropin receptor (LHCGR) to stimulate androgen secretion in the interstitial Leydig cells. However, a more direct, nonsteroidal role of LH mediating the spermiogenic pathway remains unclear. Using a flatfish with semicystic spermatogenesis, in which spermatids are released into the seminiferous lobule lumen (SLL), where they develop into spermatozoa without direct contact with the supporting Sertoli cells, we show that haploid spermatids express the homolog of the tetrapod LHCGR (Lhcgrba). Both native Lh and intramuscularly injected His-tagged recombinant Lh (rLh) are immunodetected bound to the Lhcgrba of free spermatids in the SLL, showing that circulating gonadotropin can reach the intratubular compartment. In vitro incubation of flatfish spermatids isolated from the SLL with rLh specifically promotes their differentiation into spermatozoa, whereas recombinant follicle-stimulating hormone and steroid hormones are ineffective. Using a repertoire of molecular markers and inhibitors, we find that the Lh-Lhcgrba induction of spermiogenesis is mediated through a cAMP/PKA signaling pathway that initiates the transcription of genes potentially involved in the function of spermatozoa. We further show that Lhcgrba expression in germ cells also occurs in distantly related fishes, suggesting this feature is likely conserved in teleosts regardless of the type of germ cell development. These data reveal a role of LH in vertebrate germ cells, whereby a Lhcgrba-activated signaling cascade in haploid spermatids directs gene expression and the progression of spermiogenesis. PMID:24474769

  19. The chromosomal passenger protein birc5b organizes microfilaments and germ plasm in the zebrafish embryo.

    PubMed

    Nair, Sreelaja; Marlow, Florence; Abrams, Elliott; Kapp, Lee; Mullins, Mary C; Pelegri, Francisco

    2013-04-01

    Microtubule-microfilament interactions are important for cytokinesis and subcellular localization of proteins and mRNAs. In the early zebrafish embryo, astral microtubule-microfilament interactions also facilitate a stereotypic segregation pattern of germ plasm ribonucleoparticles (GP RNPs), which is critical for their eventual selective inheritance by germ cells. The precise mechanisms and molecular mediators for both cytoskeletal interactions and GP RNPs segregation are the focus of intense research. Here, we report the molecular identification of a zebrafish maternal-effect mutation motley as Birc5b, a homolog of the mammalian Chromosomal Passenger Complex (CPC) component Survivin. The meiosis and mitosis defects in motley/birc5b mutant embryos are consistent with failed CPC function, and additional defects in astral microtubule remodeling contribute to failures in the initiation of cytokinesis furrow ingression. Unexpectedly, the motley/birc5b mutation also disrupts cortical microfilaments and GP RNP aggregation during early cell divisions. Birc5b localizes to the tips of astral microtubules along with polymerizing cortical F-actin and the GP RNPs. Mutant Birc5b co-localizes with cortical F-actin and GP RNPs, but fails to associate with astral microtubule tips, leading to disorganized microfilaments and GP RNP aggregation defects. Thus, maternal Birc5b localizes to astral microtubule tips and associates with cortical F-actin and GP RNPs, potentially linking the two cytoskeletons to mediate microtubule-microfilament reorganization and GP RNP aggregation during early embryonic cell cycles in zebrafish. In addition to the known mitotic function of CPC components, our analyses reveal a non-canonical role for an evolutionarily conserved CPC protein in microfilament reorganization and germ plasm aggregation. PMID:23637620

  20. Surrogate Production of Eggs and Sperm by Intrapapillary Transplantation of Germ Cells in Cytoablated Adult Fish

    PubMed Central

    Majhi, Sullip Kumar; Hattori, Ricardo Shohei; Rahman, Sheikh Mustafizur; Strüssmann, Carlos Augusto

    2014-01-01

    Germ cell transplantation (GCT) is a promising assisted reproductive technology for the conservation and propagation of endangered and valuable genetic resources. In teleost fish, GCT in adult gonads has been achieved only in male recipients, limiting greatly the usefulness of this technique in situations where both sexes need equal and timely attention for conservation and/or propagation. Here we describe a simplified GCT approach that ultimately leads to production of donor-derived eggs and sperm in considerably short time. Donor germ cells isolated from young pejerrey Odontesthes bonariensis (Atherinopsidae) were transplanted non-surgically through the genital papilla into the sexually mature gonads of Patagonian pejerrey O. hatcheri recipients whose gonads have been depleted of endogenous GCs by heat (26°C) and chemical treatment (four doses of Busulfan at 30 mg/kg and 40 mg/kg for females and males, respectively). Transplanted spermatogonial and oogonial cells were able to recolonize the recipients' gonads and produce functional donor origin eggs and sperm within 7 months from the GCT. We confirmed the presence of donor-derived gametes by PCR in 17% and 5% of the surrogate O. hatcheri fathers and mothers, respectively. The crosses between surrogate fathers and O. bonariensis mothers yielded 12.6–39.7% pure O. bonariensis and that between a surrogate mother and an O. bonariensis father yielded 52.2% pure O. bonariensis offspring. Our findings confirm that transplantation of germ cells into sexually competent adult fish by non-surgical methods allows the production of functional donor-derived eggs and sperm in a considerably short time. The methods described here could play a vital role in conservation and rapid propagation of endangered fish genetic resources. PMID:24748387

  1. The interactions of dietary tomato powder and soy germ on prostate carcinogenesis in the TRAMP model.

    PubMed

    Zuniga, Krystle E; Clinton, Steven K; Erdman, John W

    2013-06-01

    The interactions between bioactive-rich food components within a complex human diet for the inhibition of prostate carcinogenesis are largely unknown and difficult to quantify in humans. Tomato and soy products have each shown anti-prostate cancer (PCa) activity in laboratory studies. The objective of this study was to determine the efficacy of dietary tomato and soy germ, alone and in combination, for the inhibition of PCa in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. At 4 weeks of age, male C57BL/6 × FVB TRAMP mice (n = 119) were randomized to consume: AIN-93G control, 10% whole tomato powder (TP), 2% soy germ powder (SG), or 10% tomato powder with 2% soy germ powder (TP+SG) for 14 weeks. One hundred percent of mice fed the control diet had PCa, whereas PCa incidence was significantly lower in mice consuming TP (61%, P < 0.001), SG (66%, P < 0.001), and TP+SG (45%, P < 0.001). Although the protection offered by the combination of TP and SG was not synergistic, it was the most effective intervention. TP, SG, and TP+SG increased apoptotic index (AI) and modestly reduced the proliferative index (PI) in the prostate epithelium of TRAMP mice exhibiting primarily prostatic intraepithelial neoplasia. The dramatic reduction in the PI/AI ratio by the dietary interventions suggests that the control mice experience a stronger stimulus for malignant progression in the prostate microenvironment. Maximally effective and safe strategies for PCa prevention may result from optimizing combinations of nutrients and bioactives through an orchestration of dietary patterns. PMID:23592738

  2. Fructose-Asparagine Is a Primary Nutrient during Growth of Salmonella in the Inflamed Intestine

    PubMed Central

    Ali, Mohamed M.; Newsom, David L.; González, Juan F.; Sabag-Daigle, Anice; Stahl, Christopher; Steidley, Brandi; Dubena, Judith; Dyszel, Jessica L.; Smith, Jenee N.; Dieye, Yakhya; Arsenescu, Razvan; Boyaka, Prosper N.; Krakowka, Steven; Romeo, Tony; Behrman, Edward J.; White, Peter; Ahmer, Brian M. M.

    2014-01-01

    Salmonella enterica serovar Typhimurium (Salmonella) is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn), which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10?/? mice). The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1? SPI2? or ttrA mutants, respectively). The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies. PMID:24967579

  3. Movements restriction and alterations of the number of spines distributed along the apical shafts of layer V pyramids in motor and primary sensory cortices of the peripubertal and adult rat.

    PubMed

    Sala-Catala, J; Torrero, C; Regalado, M; Salas, M; Ruiz-Marcos, A

    2005-01-01

    The number and distribution of spines along apical shafts of rapid-Golgi-stained layer V pyramidal cells from visual, motor and somatosensory cortical areas were analyzed in control and movement-restricted (beginning at 20 days old) Wistar rats killed at 30, 40, 80 and 120 days of age (experiment A). In other group of rats, spine density was analyzed when restriction initiates on day 40 and the animals were killed at 50, 60 and 80 days postpartum, or after restriction starting on day 80 and killed at 120 days of age (experiment B). It has been found that the restriction of movements significantly reduces the total number of spines on apical shafts in the three cortical areas, when this condition starts at 20, 40 or 80 days without changing the overall distribution of spines. Also present findings indicate that the effects of movements restriction are attenuated when they were concurrent with maturational brain processes (20-40 days) than when they occurred later in life. The question remains open of which part of the measured reduction on the number of spines is due to the immobilization and which to the stress associated with this maneuver. PMID:15893637

  4. Developmental plasticity of bacterial colonies and consortia in germ-free and gnotobiotic settings

    PubMed Central

    2012-01-01

    Background Bacteria grown on semi-solid media can build two types of multicellular structures, depending on the circumstances. Bodies (colonies) arise when a single clone is grown axenically (germ-free), whereas multispecies chimeric consortia contain monoclonal microcolonies of participants. Growth of an axenic colony, mutual interactions of colonies, and negotiation of the morphospace in consortial ecosystems are results of intricate regulatory and metabolic networks. Multicellular structures developed by Serratia sp. are characteristically shaped and colored, forming patterns that reflect their growth conditions (in particular medium composition and the presence of other bacteria). Results Building on our previous work, we developed a model system for studying ontogeny of multicellular bacterial structures formed by five Serratia sp. morphotypes of two species grown in either "germ-free" or "gnotobiotic" settings (i.e. in the presence of bacteria of other conspecific morphotype, other Serratia species, or E. coli). Monoclonal bodies show regular and reproducible macroscopic appearance of the colony, as well as microscopic pattern of its growing margin. Standard development can be modified in a characteristic and reproducible manner in close vicinity of other bacterial structures (or in the presence of their products). Encounters of colonies with neighbors of a different morphotype or species reveal relationships of dominance, cooperation, or submission; multiple interactions can be summarized in "rock – paper – scissors" network of interrelationships. Chimerical (mixed) plantings consisting of two morphotypes usually produced a “consortium” whose structure is consistent with the model derived from interaction patterns observed in colonies. Conclusions Our results suggest that development of a bacterial colony can be considered analogous to embryogenesis in animals, plants, or fungi: to proceed, early stages require thorough insulation from the rest of the biosphere. Only later, the newly developing body gets connected to the ecological interactions in the biosphere. Mixed “anlagen” cannot accomplish the first, germ-free phase of development; hence, they will result in the consortium of small colonies. To map early development and subsequent interactions with the rest of the biospheric web, simplified gnotobiotic systems described here may turn to be of general use, complementing similar studies on developing multicellular eukaryots under germ-free or gnotobiotic conditions. PMID:22894147

  5. The metabolism of some xenobiotics in germ-free and conventional rats.

    PubMed

    Macholz, R; Kujawa, M; Schulze, J; Lewerenz, H J; Schnaak, W

    1985-01-01

    The different participation of the gastrointestinal microflora in the biotransformation of gamma-hexachlorcyclohexane (gamma-HCH), azobenzene and the isolated glucosinolate progoitrin was studied. Marked dehydrochlorination of gamma-HCH to gamma-pentachlorcyclohexene (PCCH) also occurs without participation of the microflora. Azobenzene was reduced in germ-free (g) and conventional (c) rats to hydrazobenzene but was split to aniline only in c-rats. Progoitrin was split with and without the influence of the microflora, but the splitting was more complete in rats with intact gastrointestinal flora. PMID:2420308

  6. Intracranial multiple germ cell tumors: a case report and review of literature

    PubMed Central

    Yang, Ping; Li, Liang; Kuang, Weiping; Li, Bo; Zhou, Bin; Yang, Jingjing; Huang, Huiyong

    2014-01-01

    Intracranial multiple germ cell tumors (GCTs) are rare. In this article, we reported a case of intracranial multiple GCTs in an 18-year-old boy with symptoms of psychosis for 8 months also. Tumors in the pineal, sellar region, corpus callosum, bilateral lateral ventricles and fourth ventricle were confirmed by enhanced magnetic resonance imaging (MRI) and stereotactic biopsy. Immunohistochemical analysis results demonstrated that the tumor cells were positive for CD117 and placental alkaline phosphatase (PLAP). The patient was treated by radiotherapy and the prescribed radiation doses were 18 Gy. After near 24 months of follow-up, no local recurrence and distant metastasis has been found. PMID:25674279

  7. Role of Extraretroperitoneal Surgery in Patients with Metastatic Germ Cell Tumors.

    PubMed

    Hu, Brian; Daneshmand, Siamak

    2015-08-01

    Surgery remains an integral component of treating metastatic testicular germ cell tumors outside the retroperitoneum. Defining the role of surgery in extraretroperitoneal (ERP) disease can be challenging because metastases can vary in terms their volume, pattern, timing, and responsiveness to systemic therapy. Some of the philosophies on treating ERP disease have come from robust data on outcomes following postchemotherapy retroperitoneal lymph node dissection. The remaining knowledge is gained from retrospective series of different ERP sites from institutions with expertise in treating testis cancer. This article describes how ERP surgery should be integrated into a multidisciplinary treatment plan. PMID:26216824

  8. Histogegesis of the Female Germ Cell in Orthoptera with Special Reference to Mermiria Bivitata

    E-print Network

    Schmitt, Edwin C.

    1913-05-15

    ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Histogegesis of the Female Germ Cell in Orthoptera with Special Reference to Mermiria Bivitata May 15, 1913 by Edwin C. Schmitt This work was digitized by the Scholarly.... (1906) Paris, pps. 306-320. PACKARD, A. S.-Textbook of Entomology. (1903) Brown University, pps. 515-586. WIEMAN, H. L.-The Pole Disc of Chrysomelid Eggs. (March,'10) Biological Bulletin* Vol. 18, No.4. WHEELER, W. M.-A Contribution to Insect...

  9. Appearance pattern of tooth germs with developmental process in Mylopharyngodon piceus

    NASA Astrophysics Data System (ADS)

    Yue, Pei-Qi; Nakajima, Tsuneo

    1995-06-01

    The pharyngeal dental formula of Mylopharyngodon piceus is 4 5 as a rule, and the dentition is asymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearance pattern of tooth germ with development process in this fish is described in detail. The formation pattern of the left dentition is contrasted with that of the right one. In the developmental process, the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designated by Nakajima (1984), while the right one is A-type.

  10. Germ cell DNA-repair systems-possible tools in cancer research?

    PubMed

    Helle, F

    2012-04-01

    A major dogma in cancer research is that cancer begins at the cellular level. Because of this single-cell origin, evolutionary principles have often been used to explain how somatic cancer cells are selected at a sub-individual level. The traditional application of Darwinian theory, however, in which the colony of cells constituting an individual is regarded as a whole, has not been applied extensively to the understanding of cancer until recently. Two proponents for this view, Breivik and Gaudernack, have suggested that in certain situations the cost of DNA repair might exceed the cost of errors. This model predicts that genetic stability is configured for an optimal cost-benefit relationship. Natural selection is not expected to have produced the best genetic stability available in the human body, merely the best compromise of DNA repair and costs. Repair and maintenance of the vast human genome is thermodynamically expensive, and an optimal balance between DNA repair and dietary needs is likely to have originated. Furthermore, fast growth conveys significant advantages such as early maturation or cognitive development, but usually at the expense of replication accuracy. Thus, a compromise between growth speed and cancer risk is likely to have taken place. These and other ecological mechanisms have probably prevented genomic stability to reach its full potential in the human body. In contrast, germ lines express near perfect DNA maintenance. Although germ cells are specialized DNA-conserving cells with few other functions, it's not given that their proteins will all be incompatible with the somatic cell. One approach to study this would be to systematically explore which DNA-stability and -repair systems are unique in germ cells, and induce their expression in invertebrate and mammalian model organisms. This could unveil which DNA-repair systems are switched off in the somatic cell lines, as they are incompatible, and which are absent due to evolution. The present review discuss different DNA-repair systems and cell cycle check point control mechanisms shown to be different or unique in the germ cell, and how they may be utilized in cancer therapy. PMID:22322886

  11. Transcriptomic profiling comparison of YAP over-expression and conditional knockout mouse tooth germs.

    PubMed

    Liu, Ming; Wang, Xiu-Ping

    2015-09-01

    To identify the downstream target genes of YAP, we used RNA-Seq technology to compare the transcriptomic profilings of Yap conditional knockout (Yap CKO) and YAP over-expression mouse tooth germs. Our results showed that some Hox, Wnt and Laminin family genes had concurrent changes with YAP transcripts, indicating that the expression of these genes may be regulated by YAP. Here, we provide the detailed experimental procedure for the transcriptomic profiling results (NCBI GEO accession number GSE65524). The associated study on the regulation of Hoxa1 and Hoxc13 genes by YAP was published in Molecular Cellular Biology in 2015 [Liu et al., 2015]. PMID:26484260

  12. The altered gravity effect on proliferative system of two-day pea germs

    NASA Astrophysics Data System (ADS)

    Artemenko, O. A.

    The study of clinorotation effect on proliferative system sensibility of plants is very important for understanding and future investigations of their development characteristics and for examination of cell cycle regulation molecular mechanisms. Determination of two-day pea germ mitotic activity of cells, correlation of mitosis phase and DNA content point to decrease of these parameters under clinorotation during the first 12 hours of the factor influence. Cell cycle stabilization after 12 hours of the experiment show high adaptation capacity of plant proliferative system.

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

    PubMed Central

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

    2008-01-01

    Background Most testicular germ cell tumors arise from intratubular germ cell neoplasia unclassified (IGCNU, also referred to as carcinoma in situ), which is thought to originate from a transformed primordial germ cell (PGC)/gonocyte, the fetal germ cell. Analyses of the molecular profile of IGCNU and seminoma show similarities to the expression profile of fetal germ cells/gonocytes. In murine PGCs, expression and interaction of Blimp1 and Prmt5 results in arginine 3 dimethylation of histone H2A and H4. This imposes epigenetic modifications leading to transcriptional repression in mouse PGCs enabling them to escape the somatic differentiation program during migration, while expressing markers of pluripotency. Results In the present study, we show that BLIMP1 and PRMT5 were expressed and arginine dimethylation of histones H2A and H4 was detected in human male gonocytes at weeks 12–19 of gestation, indicating a role of this mechanism in human fetal germ cell development as well. Moreover, BLIMP1/PRMT5 and histone H2A and H4 arginine 3 dimethylation was present in IGCNU and most seminomas, while downregulated in embryonal carcinoma (EC) and other nonseminomatous tumors. Conclusion These data reveal similarities in marker expression and histone modification between murine and human PGCs. Moreover, we speculate that the histone H2A and H4 arginine 3 dimethylation might be the mechanism by which IGCNU and seminoma maintain the undifferentiated state while loss of these histone modifications leads to somatic differentiation observed in nonseminomatous tumors. PMID:18992153

  14. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (editor); Moorehead, Tauna W. (editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  15. Transport Layer Cornell University

    E-print Network

    Low, Steven H.

    directions for the future evolution of the transport layer and suggest some further reading in sections VITransport Layer Ao Tang Cornell University Ithaca, NY 14853 Lachlan L. H. Andrew California of the physical layer, the link layer, the network layer, the transport layer and the application layer1 . See

  16. Primary Production in Antarctic Sea Ice

    NASA Technical Reports Server (NTRS)

    Arrigo, Kevin R.; Worthen, Denise L.; Lizotte, Michael P.; Dixon, Paul; Dieckmann, Gerhard

    1997-01-01

    A numerical model shows that in Antarctic sea ice, increased flooding in regions with thick snow cover enhances primary production in the infiltration (surface) layer. Productivity in the freeboard (sea level) layer is also determined by sea ice porosity, which varies with temperature. Spatial and temporal variation in snow thickness and the proportion of first-year ice thus determine regional differences in sea ice primary production. Model results show that of the 40 tera-grams of carbon produced annually in the Antarctic ice pack, 75 percent was associated with first-year ice and nearly 50 percent was produced in the Weddell Sea.

  17. Epigenetic patterns maintained in early Caenorhabditis elegans embryos can be established by gene activity in the parental germ cells.

    PubMed

    Arico, Jackelyn K; Katz, David J; van der Vlag, Johan; Kelly, William G

    2011-06-01

    Epigenetic information, such as parental imprints, can be transmitted with genetic information from parent to offspring through the germ line. Recent reports show that histone modifications can be transmitted through sperm as a component of this information transfer. How the information that is transferred is established in the parent and maintained in the offspring is poorly understood. We previously described a form of imprinted X inactivation in Caenorhabditis elegans where dimethylation on histone 3 at lysine 4 (H3K4me2), a mark of active chromatin, is excluded from the paternal X chromosome (Xp) during spermatogenesis and persists through early cell divisions in the embryo. Based on the observation that the Xp (unlike the maternal X or any autosome) is largely transcriptionally inactive in the paternal germ line, we hypothesized that transcriptional activity in the parent germ line may influence epigenetic information inherited by and maintained in the embryo. We report that chromatin modifications and histone variant patterns assembled in the germ line can be retained in mature gametes. Furthermore, despite extensive chromatin remodeling events at fertilization, the modification patterns arriving with the gametes are largely retained in the early embryo. Using transgenes, we observe that expression in the parental germline correlates with differential chromatin assembly that is replicated and maintained in the early embryo. Expression in the adult germ cells also correlates with more robust expression in the somatic lineages of the offspring. These results suggest that differential expression in the parental germ lines may provide a potential mechanism for the establishment of parent-of-origin epigenomic content. This content can be maintained and may heritably affect gene expression in the offspring. PMID:21695223

  18. Germ Wars

    ERIC Educational Resources Information Center

    Alderson, Kris

    2009-01-01

    It's estimated that at least 22 million school days are lost every year because of colds caught by students and faculty, according to the Centers for Disease Control and Prevention (CDC). There's still no cure for the common cold, but there is a time-honored way to prevent it: handwashing, ideally with good old soap and water. It's still the best…

  19. Mouse Tafazzin Is Required for Male Germ Cell Meiosis and Spermatogenesis

    PubMed Central

    Cadalbert, Laurence C.; Ghaffar, Farah Naz; Stevenson, David; Bryson, Sheila; Vaz, Frédéric M.; Gottlieb, Eyal; Strathdee, Douglas

    2015-01-01

    Barth syndrome is an X-linked mitochondrial disease, symptoms of which include neutropenia and cardiac myopathy. These symptoms are the most significant clinical consequences of a disease, which is increasingly recognised to have a variable presentation. Mutation in the Taz gene in Xq28 is thought to be responsible for the condition, by altering mitochondrial lipid content and mitochondrial function. Male chimeras carrying a targeted mutation of Taz on their X-chromosome were infertile. Testes from the Taz knockout chimeras were smaller than their control counterparts and this was associated with a disruption of the progression of spermatocytes through meiosis to spermiogenesis. Taz knockout ES cells also showed a defect when differentiated to germ cells in vitro. Mutant spermatocytes failed to progress past the pachytene stage of meiosis and had higher levels of DNA double strand damage and increased levels of endogenous retrotransposon activity. Altogether these data revealed a novel role for Taz in helping to maintain genome integrity in meiosis and facilitating germ cell differentiation. We have unravelled a novel function for the Taz protein, which should contribute to an understanding of how a disruption of the Taz gene results in the complex symptoms underlying Barth Syndrome. PMID:26114544

  20. Immunoglobulin knockout chickens via efficient homologous recombination in primordial germ cells

    PubMed Central

    Schusser, Benjamin; Collarini, Ellen J.; Yi, Henry; Izquierdo, Shelley Mettler; Fesler, Jeffrey; Pedersen, Darlene; Klasing, Kirk C.; Kaspers, Bernd; Harriman, William D.; van de Lavoir, Marie-Cecile; Etches, Robert J.; Leighton, Philip A.

    2013-01-01

    Gene targeting by homologous recombination or by sequence-specific nucleases allows the precise modification of genomes and genes to elucidate their functions. Although gene targeting has been used extensively to modify the genomes of mammals, fish, and amphibians, a targeting technology has not been available for the avian genome. Many of the principles of humoral immunity were discovered in chickens, yet the lack of gene targeting technologies in birds has limited biomedical research using this species. Here we describe targeting the joining (J) gene segment of the chicken Ig heavy chain gene by homologous recombination in primordial germ cells to establish fully transgenic chickens carrying the knockout. In homozygous knockouts, Ig heavy chain production is eliminated, and no antibody response is elicited on immunization. Migration of B-lineage precursors into the bursa of Fabricius is unaffected, whereas development into mature B cells and migration from the bursa are blocked in the mutants. Other cell types in the immune system appear normal. Chickens lacking the peripheral B-cell population will provide a unique experimental model to study avian immune responses to infectious disease. More generally, gene targeting in avian primordial germ cells will foster advances in diverse fields of biomedical research such as virology, stem cells, and developmental biology, and provide unique approaches in biotechnology, particularly in the field of antibody discovery. PMID:24282302

  1. Modeling the Epithelial Morphogenesis of Germ Band Retraction in Three Dimensions

    NASA Astrophysics Data System (ADS)

    McCleery, W. Tyler; Veldhuis, Jim; Brodland, G. Wayne; Crews, Sarah M.; Hutson, M. Shane

    2015-03-01

    Embryogenesis of higher-order organisms is driven by an intricate coordination of cellular mechanics. Mechanical analysis of certain developmental events, e.g., dorsal closure in the fruit fly D. melanogaster, has been sufficiently described using two-dimensional models. Here, we present a three-dimensional modeling technique to investigate germ band retraction (GBR) - a whole-embryo, irreducibly 3D morphogenetic event. At the start of GBR, the epithelial tissue known as the germ band is initially wrapped around the posterior end of an ellipsoidal fly embryo. This tissue then retracts as an adjacent epithelial tissue, the amnioserosa, simultaneously contracts. We hypothesize that proper GBR requires maintenance of cell-cell connectivity in the amnioserosa, as well as both cell and tissue topology on the embryo's ellipsoidal surface. The exact interfacial tensions are less important. We test the dynamic interactions between these two tissues on a 3D ellipsoidal last. To speed simulation run times and focus on the relevant tissues, epithelial cells are defined as polygons constrained to lie on the surface of the ellipsoidal last. These cells have adjustable parameters such as edge tensions and cell pressures. Tissue movements are simulated by balancing these dynamic cell-level forces with viscous resistance and allowing cells to exchange neighbors. This modeling approach helps elucidate the multicellular stress fields in normal and aberrant development, providing deeper insight into the mechanical interdependence of developing tissues.

  2. Conceptual links between DNA methylation reprogramming in the early embryo and primordial germ cells.

    PubMed

    Seisenberger, Stefanie; Peat, Julian R; Reik, Wolf

    2013-06-01

    DNA methylation is a carrier of important regulatory information that undergoes global reprogramming in the mammalian germ line, including pre-implantation embryos and primordial germ cells (PGCs). A flurry of recent studies have employed technical advances to generate global profiles of methylation and hydroxymethylation in these cells, unravelling the dynamics of methylation erasure at single locus resolution. Active demethylation in the zygote, involving extensive oxidation, is followed by passive loss over early cell divisions. Certain gamete-contributed methylation marks appear to have evolved non-canonical mechanisms for targeted maintenance of methylation in the face of these processes. These protected sequences include the imprinting control regions (ICRs) required for parental imprinting but also a surprising number of other regions. Such targeted maintenance mechanisms may also operate at certain sequences during early PGC migration when global passive demethylation occurs. In later gonadal PGCs, imprints must be reset and this may be achieved through the targeting of active mechanisms including oxidation. Thus, emerging evidence paints a complex picture whereby active and passive demethylation pathways operate synergistically and in parallel to ensure robust erasure in the early embryo and PGCs. PMID:23510682

  3. Production of reproductively sterile fish: A mini-review of germ cell elimination technologies.

    PubMed

    Wong, Ten-Tsao; Zohar, Yonathan

    2015-09-15

    As seafood consumption shifts from fisheries harvests to artificially propagated aquatic species, the increase of aquaculture activities poses a biological threat to our environment. Selectively bred, non-native and (eventually) genetically engineered farmed fish may escape from aquaculture operations, propagate and/or interbreed with wild stocks and subsequently alter the genetic makeup of populations in the environment. Thus, an effective strategy for bio-containment of farmed fish is critically needed. Farming reproductively sterile fish is the most environmentally sustainable approach to ensure complete bio-containment in large-scale aquaculture operations. Chromosome set manipulations to produce sterile fish, including polyploidy and hybridization, are currently the most common practices in the aquaculture industry. However, they do not always result in 100% sterility of the treated fish. Moreover, triploid fish typically do not perform as well as the non-manipulated diploids under commercial culture conditions. In the last half decade, several genetic engineering methods have been developed to produce sterile fish. In this review, we will address the latest technologies that use transgenic approaches to eliminate germ cells, resulting in the production of sterile fish. These latest advances also led us to the development of egg/embryo immersion methodologies to deliver and screen compounds that can be used to eliminate primordial germ cells and produce sterile fish. This emerging non-transgenic strategy for the production of reproductively sterile fish in aquaculture will also be discussed. PMID:25583581

  4. The effect of fluoride on mineralization during tooth germ development in neonatal hamsters

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Lyaruu, D. M.; Vis, R. D.

    1990-04-01

    The effect of fluoride on calcium and phosphorus content (a measure for mineralization) in maxillary first molar tooth germs from neonatal hamsters (4 to 5 days old, 4 to 5 g body weight) was analysed using the proton nuclear microprobe PIXE setup of the Vrije Universiteit. A 3 MeV proton beam of about 500 pA with a spot size of 5 × 20 ?m 2 was used to perform scans of about 400 ?m, each taking about 20 to 30 minutes. The smaller beam dimension was always tuned parallel to the scan direction. Line scans with a lateral resolution of 5 ?m were made across the enamel organ of germs from animals injected with 20 mg NaF/kg body weight 24 h prior to dissection. The control animals were injected with NaCl. Fluoride administration induced the formation of sub-ameloblastic cystic lesions under some (but not all) populations of transitional and secretory ameloblasts, accompanied by hypermineralization (deposition of more mineral than that found in the controls) of the underlying enamel surface. These hypermineralized regions had been shown in earlier studies to contain elevated fluorine content [1,2].

  5. Prp22 and Spliceosome Components Regulate Chromatin Dynamics in Germ-Line Polyploid Cells

    PubMed Central

    Klusza, Stephen; Novak, Amanda; Figueroa, Shirelle; Palmer, William; Deng, Wu-Min

    2013-01-01

    During Drosophila oogenesis, the endopolyploid nuclei of germ-line nurse cells undergo a dramatic shift in morphology as oogenesis progresses; the easily-visible chromosomes are initially polytenic during the early stages of oogenesis before they transiently condense into a distinct ‘5-blob’ configuration, with subsequent dispersal into a diffuse state. Mutations in many genes, with diverse cellular functions, can affect the ability of nurse cells to fully decondense their chromatin, resulting in a ‘5-blob arrest’ phenotype that is maintained throughout the later stages of oogenesis. However, the mechanisms and significance of nurse-cell (NC) chromatin dispersal remain poorly understood. Here, we report that a screen for modifiers of the 5-blob phenotype in the germ line isolated the spliceosomal gene peanuts, the Drosophila Prp22. We demonstrate that reduction of spliceosomal activity through loss of peanuts promotes decondensation defects in NC nuclei during mid-oogenesis. We also show that the Prp38 spliceosomal protein accumulates in the nucleoplasm of nurse cells with impaired peanuts function, suggesting that spliceosomal recycling is impaired. Finally, we reveal that loss of additional spliceosomal proteins impairs the full decondensation of NC chromatin during later stages of oogenesis, suggesting that individual spliceosomal subcomplexes modulate expression of the distinct subset of genes that are required for correct morphology in endopolyploid nurse cells. PMID:24244416

  6. Effects of bread making and wheat germ addition on the natural deoxynivalenol content in bread.

    PubMed

    Giménez, Isabel; Blesa, Jesús; Herrera, Marta; Ariño, Agustín

    2014-01-01

    Deoxynivalenol (DON, vomitoxin) is a type-B trichothecene mycotoxin produced by several field fungi such as Fusarium graminearum and Fusarium culmorum and known to have various toxic effects. This study investigated the effect of the bread making process on the stability of DON in common bread and wheat germ-enriched bread using naturally contaminated ingredients at the level of 560 µg/kg. The concentration of DON and its evolution during bread making were determined by immunoaffinity column cleanup followed by liquid chromatography with diode array detection (HPLC-DAD). During the bread making process, DON was reduced by 2.1% after fermentation and dropped by 7.1% after baking, reaching a maximum reduction of 19.8% in the crust as compared with a decrease of 5.6% in the crumb. The addition of 15% wheat germ to the dough did not affect DON stability during bread making, showing an apparent increase of 3.5% after fermentation and a reduction by 10.2% after baking. PMID:24451845

  7. Germ cell toxicity: significance in genetic and fertility effects of radiation and chemicals

    SciTech Connect

    Oakberg, E.F.

    1983-01-01

    The response of the male and female to radiation and chemicals is different. Any loss of oocytes in the female cannot be replaced, and if severe enough, will result in a shortening of the reproductive span. In the male, a temporary sterile period may be induced owing to destruction of the differentiating spermatogonia, but the stem cells are the most resistant spermatogonial type, are capable of repopulating the seminiferous epithelium, and fertility usually returns. The response of both the male and female changes with development of the embryonic to the adult gonad, and with differentiation and maturation in the adult. The primordial germ cells, early oocytes, and differentiating spermatogonia of the adult male are unusually sensitive to the cytotoxic action of noxious agents, but each agent elicits a specific response owing to the intricate biochemical and physiological changes associated with development and maturation of the gametes. The relationship of germ cell killing to fertility is direct, and long-term fertility effects can be predicted from histological analysis of the gonads. The relationship to genetic effects, on the other hand, is indirect, and acts primarily by limiting the cell stages available for testing, by affecting the distribution of mitotically active stem cells among the different stages of the mitotic cycle, and thereby, changing both the type and frequency of genetic effects observed. 100 references, 38 figures, 7 tables.

  8. A Small RNA-Based Immune System Defends Germ Cells against Mobile Genetic Elements

    PubMed Central

    2016-01-01

    Transposons are mobile genetic elements that threaten the survival of species by destabilizing the germline genomes. Limiting the spread of these selfish elements is imperative. Germ cells employ specialized small regulatory RNA pathways to restrain transposon activity. PIWI proteins and Piwi-interacting RNAs (piRNAs) silence transposons at the transcriptional and posttranscriptional level with loss-of-function mutant animals universally exhibiting sterility often associated with germ cell defects. This short review aims to illustrate basic strategies of piRNA-guided defense against transposons. Mechanisms of piRNA silencing are most readily studied in Drosophila melanogaster, which serves as a model to delineate molecular concepts and as a reference for mammalian piRNA systems. PiRNA pathways utilize two major strategies to handle the challenges of transposon control: (1) the hard-wired molecular memory of prior transpositions enables recognition of mobile genetic elements and discriminates transposons from host genes; (2) a feed-forward adaptation mechanism shapes piRNA populations to selectively combat the immediate threat of transposon transcripts. In flies, maternally contributed PIWI-piRNA complexes bolster both of these lines of defense and ensure transgenerational immunity. While recent studies have provided a conceptual framework of what could be viewed as an ancient immune system, we are just beginning to appreciate its many molecular innovations. PMID:26681955

  9. Endocytosis and membrane turnover in the germ tube of uromyces fabae

    PubMed

    Hoffmann; Mendgen

    1998-06-01

    We have used the fluorescent dye FM4-64 as a tracer to demonstrate bulk membrane internalization (endocytosis) and redistribution of the dye within the cytoplasm of the germ tube of the rust fungus Uromyces fabae. Staining of the hyphal membrane was detected 4 s after application of FM4-64 and reached a maximum after 1 min. The highest fluorescence intensity occurred in the apex. Subsequently, staining of the plasma membrane decreased and a subapical region of the fungal protoplast (5-20 &mgr;m from the tip) displayed increasing fluorescence with a maximum after 5 min. Fluorescence in the subapical region was redistributed to an area in the hyphal tip, which corresponds to the accumulation of apical vesicles, after 10-15 min and subsequently to a cytoplasmic region in front of the two nuclei (35-45 &mgr;m from the tip). We conclude from our measurements of membrane fluorescence that the turnover time from endocytosis to secretion of the dye amounts to 15 min. The uptake of the dye into the cytoplasm, but not membrane loading, could be inhibited completely with 5 mM NaN3 or by a temperature shift to 4 degreesC. This is the first evidence for endocytosis in a fungal germ tube. Copyright 1998 Academic Press. PMID:9742194

  10. Establishment of a germ carrier assay to assess disinfectant efficacy against oocysts of coccidian parasites.

    PubMed

    Dresely, Ira; Daugschies, Arwid; Lendner, Matthias

    2015-01-01

    Parasites are a common threat to human and animal health. One option to combat parasites that produce infective environmental stages is to inactivate them by chemical disinfection. Standardised laboratory assays that enable proper evaluation of products suspected to be efficient are highly desirable to allow prudent selection and use of such potentially hazardous agents. Here, we present a newly developed in vitro germ carrier assay to evaluate inactivation of oocysts of the model organism Cryptosporidium parvum by chemical disinfectants. Stainless steel discs were used as carrier to mimic surface contamination by C. parvum oocysts. The germ carriers were incubated with approved chemical disinfectant for the specified time (2 h) and rinsed thereafter to remove the disinfectant and recover the exposed oocysts. Recovered oocysts were transferred to HCT-8 monolayers, and 48 h later, genomic DNA was extracted and quantified by real-time PCR targeting the hsp70 gene to estimate parasite reproduction. A panel of commercially available and approved disinfectants were examined and data compared with those of suspension assays and historical data obtained from efficacy assays based on infection of chicken with oocysts of Eimeria tenella. Altogether, data achieved by these divergent assays allowed similar conclusions although the sensitivity of the in vitro assay was higher. Consequently, a threshold of 99.5% inactivation is proposed to evaluate disinfectants in vitro using C. parvum as model organism as compared to the E. tenella animal infection assay (95%). PMID:25339515

  11. Relative susceptibilities of male germ cells to genetic defects induced by cancer chemotherapies

    SciTech Connect

    Wyrobek, A J; Schmid, T E; Marchetti, F

    2004-06-15

    Some chemotherapy regimens include agents that are mutagenic or clastogenic in model systems. This raises concerns that cancer survivors, who were treated before or during their reproductive years, may be at increased risks for abnormal reproductive outcomes. However, the available data from offspring of cancer survivors are limited, representing diverse cancers, therapies, time-to-pregnancies, and reproductive outcomes. Rodent breeding data after paternal exposures to individual chemotherapeutic agents illustrate the complexity of factors that influence the risk for transmitted genetic damage including agent, dose, endpoint, and the germ-cell susceptibility profiles that vary across agents. Direct measurements of chromosomal abnormalities in sperm of mice and humans by sperm FISH have corroborated the differences in germ-cell susceptibilities. The available evidence suggests that the risk of producing chromosomally defective sperm is highest during the first few weeks after the end of chemotherapy, and decays with time. Thus, sperm samples provided immediately after the initiation of cancer therapies may contain treatment-induced genetic defects that will jeopardize the genetic health of offspring.

  12. Reduced insulin/IGF-1 signaling restores germ cell immortality to Caenorhabditis elegans Piwi mutants.

    PubMed

    Simon, Matt; Sarkies, Peter; Ikegami, Kohta; Doebley, Anna-Lisa; Goldstein, Leonard D; Mitchell, Jacinth; Sakaguchi, Aisa; Miska, Eric A; Ahmed, Shawn

    2014-05-01

    Defects in the Piwi/piRNA pathway lead to transposon desilencing and immediate sterility in many organisms. We found that the C. elegans Piwi mutant prg-1 became sterile after growth for many generations. This phenotype did not occur for RNAi mutants with strong transposon-silencing defects and was separable from the role of PRG-1 in transgene silencing. Brief periods of starvation extended the transgenerational lifespan of prg-1 mutants by stimulating the DAF-16/FOXO longevity transcription factor. Constitutive activation of DAF-16 via reduced daf-2 insulin/IGF-1 signaling immortalized prg-1 strains via RNAi proteins and histone H3 lysine 4 demethylases. In late-generation prg-1 mutants, desilencing of repetitive segments of the genome occurred, and silencing of repetitive loci was restored in prg-1; daf-2 mutants. This study reveals an unexpected interface between aging and transgenerational maintenance of germ cells, where somatic longevity is coupled to a genome-silencing pathway that promotes germ cell immortality in parallel to the Piwi/piRNA system. PMID:24767993

  13. Thermal Image of Coffee-Seed Germ Obtained by Photoacoustic Microscopy

    NASA Astrophysics Data System (ADS)

    Domínguez-Pacheco, A.; Hernández Aguilar, C.; Cruz-Orea, Alfredo; Isaac Alemán, E.; Martínez Ortiz, E.

    2013-09-01

    Photoacoustic microscopy (PAM) has been shown to be a suitable technique to obtain thermal images of a wide variety of samples from semiconductors to biological material. In PAM, the incidence of a modulated laser beam on a sample within a photoacoustic (PA) cell, hermetically sealed, produces a PA signal which depends on the thermal and optical properties of the studied sample. By making a sweep of the modulated laser beam on the sample surface, it is possible to obtain the PA signal as a function of their x- y coordinates, and from this signal, it is possible to reconstruct thermal images of the sample. In this study, thermal images of a coffee-seed germ were obtained, with a difference of 12 h between them, by using the PAM technique. Thermal differences observed between images give information which reflects degradation due to the fact that germ cells undergo changes as a function of time. The thermal images obtained by the PAM technique could be applied to biological materials that have a complex constitution (not homogeneous) in their structures, and thermal differences can be observed. PAM is a non-destructive technique, which is an important feature for this type of study. Other applications of this technique can be performed in the agricultural and biotechnological areas.

  14. Fermented Wheat Germ Extract (Avemar) in the Treatment of Cardiac Remodeling and Metabolic Symptoms in Rats

    PubMed Central

    Iyer, Abishek; Brown, Lindsay

    2011-01-01

    Avemar, a product of industrial fermentation of wheat germ with a standardized content of benzoquinone and plant flavonoids, has been tested as an anti-cancer and immunomodulatory dietary supplement. Proposed mechanisms include anti-oxidant and anti-inflammatory actions. This study has determined whether these actions of Avemar may also be useful in the treatment of cardiovascular diseases. Two experimental rat models of cardiovascular remodeling were used in this project: the deoxycorticosterone acetate (DOCA)-salt-induced model of chronic hypertension (study I) and a high-carbohydrate/high-fat diet-induced model producing chronic symptoms of the metabolic syndrome and its associated cardiovascular complications (study II). Our results in these rat models of hypertension and diet-induced obesity show that treatment with Avemar improved cardiac function, decreased macrophage infiltration resulting in decreased collagen deposition in the ventricular myocardium, reversed an increased stiffness of the left ventricle in the diseased hearts and attenuated increased plasma malondialdehyde concentrations. In addition to the changes in the heart, Avemar reversed glucose intolerance, normalized systolic blood pressure and decreased visceral fat deposition in rats fed a high-fat/high-carbohydrate diet. In conclusion, the fermented wheat germ extract Avemar has a potential role in attenuating chronic hypertension, diabetes or metabolic syndrome-induced cardiovascular symptoms along with metabolic abnormalities such as glucose tolerance and obesity. PMID:19622599

  15. Oocyte formation by mitotically-active germ cells purified from ovaries of reproductive age women

    PubMed Central

    White, Yvonne A. R.; Woods, Dori C.; Takai, Yasushi; Ishihara, Osamu; Seki, Hiroyuki; Tilly, Jonathan L.

    2012-01-01

    Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a FACS-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically-active cells that exhibit a gene expression profile consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and spontaneously generate 35–50 µm oocytes, as determined by morphology, gene expression and attainment of haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1–2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, like adult mice, possess rare mitotically-active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo. PMID:22366948

  16. A mitotic kinase scaffold depleted in testicular seminomas impacts spindle orientation in germ line stem cells.

    PubMed

    Hehnly, Heidi; Canton, David; Bucko, Paula; Langeberg, Lorene K; Ogier, Leah; Gelman, Irwin; Santana, L Fernando; Wordeman, Linda; Scott, John D

    2015-01-01

    Correct orientation of the mitotic spindle in stem cells underlies organogenesis. Spindle abnormalities correlate with cancer progression in germ line-derived tumors. We discover a macromolecular complex between the scaffolding protein Gravin/AKAP12 and the mitotic kinases, Aurora A and Plk1, that is down regulated in human seminoma. Depletion of Gravin correlates with an increased mitotic index and disorganization of seminiferous tubules. Biochemical, super-resolution imaging, and enzymology approaches establish that this Gravin scaffold accumulates at the mother spindle pole during metaphase. Manipulating elements of the Gravin-Aurora A-Plk1 axis prompts mitotic delay and prevents appropriate assembly of astral microtubules to promote spindle misorientation. These pathological responses are conserved in seminiferous tubules from Gravin(-/-) mice where an overabundance of Oct3/4 positive germ line stem cells displays randomized orientation of mitotic spindles. Thus, we propose that Gravin-mediated recruitment of Aurora A and Plk1 to the mother (oldest) spindle pole contributes to the fidelity of symmetric cell division. PMID:26406118

  17. Telomeric repeat silencing in germ cells is essential for early development in Drosophila

    PubMed Central

    Morgunova, Valeriya; Akulenko, Natalia; Radion, Elizaveta; Olovnikov, Ivan; Abramov, Yuri; Olenina, Ludmila V.; Shpiz, Sergey; Kopytova, Daria V.; Georgieva, Sofia G.; Kalmykova, Alla

    2015-01-01

    The germline-specific role of telomeres consists of chromosome end elongation and proper chromosome segregation during early developmental stages. Despite the crucial role of telomeres in germ cells, little is known about telomere biology in the germline. We analyzed telomere homeostasis in the Drosophila female germline and early embryos. A novel germline-specific function of deadenylase complex Ccr4-Not in the telomeric transcript surveillance mechanism is reported. Depletion of Ccr4-Not complex components causes strong derepression of the telomeric retroelement HeT-A in the germ cells, accompanied by elongation of the HeT-A poly(A) tail. Dysfunction of transcription factors Woc and Trf2, as well as RNA-binding protein Ars2, also results in the accumulation of excessively polyadenylated HeT-A transcripts in ovaries. Germline knockdowns of Ccr4-Not components, Woc, Trf2 and Ars2, lead to abnormal mitosis in early embryos, characterized by chromosome missegregation, centrosome dysfunction and spindle multipolarity. Moreover, the observed phenotype is accompanied by the accumulation of HeT-A transcripts around the centrosomes in early embryos, suggesting the putative relationship between overexpression of telomeric transcripts and mitotic defects. Our data demonstrate that Ccr4-Not, Woc, Trf2 and Ars2, components of different regulatory pathways, are required for telomere protection in the germline in order to guarantee normal development. PMID:26240377

  18. A Small RNA-Based Immune System Defends Germ Cells against Mobile Genetic Elements.

    PubMed

    Haase, Astrid D

    2016-01-01

    Transposons are mobile genetic elements that threaten the survival of species by destabilizing the germline genomes. Limiting the spread of these selfish elements is imperative. Germ cells employ specialized small regulatory RNA pathways to restrain transposon activity. PIWI proteins and Piwi-interacting RNAs (piRNAs) silence transposons at the transcriptional and posttranscriptional level with loss-of-function mutant animals universally exhibiting sterility often associated with germ cell defects. This short review aims to illustrate basic strategies of piRNA-guided defense against transposons. Mechanisms of piRNA silencing are most readily studied in Drosophila melanogaster, which serves as a model to delineate molecular concepts and as a reference for mammalian piRNA systems. PiRNA pathways utilize two major strategies to handle the challenges of transposon control: (1) the hard-wired molecular memory of prior transpositions enables recognition of mobile genetic elements and discriminates transposons from host genes; (2) a feed-forward adaptation mechanism shapes piRNA populations to selectively combat the immediate threat of transposon transcripts. In flies, maternally contributed PIWI-piRNA complexes bolster both of these lines of defense and ensure transgenerational immunity. While recent studies have provided a conceptual framework of what could be viewed as an ancient immune system, we are just beginning to appreciate its many molecular innovations. PMID:26681955

  19. Reversal of informational entropy and the acquisition of germ-like immortality by somatic cells.

    PubMed

    Kyriazis, Marios

    2014-01-01

    We live within an increasingly technological, information-laden environment for the first time in human evolution. This subjects us (and will continue to subject us in an accelerating fashion) to an unremitting exposure to 'meaningful information that requires action'. Directly dependent upon this new environment are novel evolutionary pressures, which can modify existing resource allocation mechanisms and may eventually favour the survival of somatic cells (particularly neurons) at the expense of germ line cells. In this theoretical paper I argue that persistent, structured information-sharing in both virtual and real domains, leads to increased biological complexity and functionality, which reflects upon human survival characteristics. Certain biological immortalisation mechanisms currently employed by germ cells may thus need to be downgraded in order to enable somatic cells to manage these new energy demands placed by our modern environment. Relevant concepts from a variety of disciplines such as the evolution of complex adaptive systems, information theory, digital hyper-connectivity, and cell immortalisation will be reviewed. Using logical, though sometimes speculative arguments, I will attempt to describe a new biology. A biology not driven by sex and reproduction but by information and somatic longevity. PMID:24852017

  20. Delayed fertilization of anuran amphibian (Xenopus) eggs leads to reduced numbers of primordial germ cells

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Several media were tested for the extent to which they promoted high fertilization efficiencies in ovulated, stripped Xenopus eggs. One medium was selected for maintaining eggs in a 'delayed fertilization' (DelF) condition. DelF eggs displayed several unusual characteristics, including shift of the center of gravity, prominent sperm entrance site, and occasional polyspermy. The frequency of normal pattern formation varied according to the length of time eggs were maintained in the DelF condition. Various developmental abnormalities were observed during gastrulation, neurulation, and organogenesis. Most abnormalities appeared, however, to be related to morphogenesis of the endoderm. Primordial germ cell (PGC) development was examined in DelF eggs which displayed normal external morphological features at the swimming tadpole stage. PGC counts were usually normal in short-duration (eg, 5 hr) DelF eggs, but frequently substantially reduced or completely diminished in longer-duration (eg, 25h) tadpoles. Six spawnings were compared and shown to exhibit considerable variability in fertility, morphogenesis, and PGC development. Yolk platelet shifts and developmental parameters were examined in two additional spawnings. The subcortical cytoplasm in which the germ plasm is normally localized appeared to be disrupted in longer duration DelF eggs. That observation may account for low PGC counts in DelF tadpoles.