Pantakani, Dasaradha Venkata Krishna

[["dc.bibliographiccitation.artnumber","e22413"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","PLoS ONE"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Xu, X."],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.contributor.author","Luehrig, Sandra"],["dc.contributor.author","Tan, Xiaoying"],["dc.contributor.author","Khromov, Tatjana"],["dc.contributor.author","Nolte, Jessica"],["dc.contributor.author","Dressel, Ralf"],["dc.contributor.author","Zechner, Ulrich"],["dc.contributor.author","Engel, Wolfgang"],["dc.date.accessioned","2018-11-07T08:54:13Z"],["dc.date.available","2018-11-07T08:54:13Z"],["dc.date.issued","2011"],["dc.description.abstract","Embryonic stem cells (ESCs) generated from the in-vitro culture of blastocyst stage embryos are known as equivalent to blastocyst inner cell mass (ICM) in-vivo. Though several reports have shown the expression of germ cell/pre-meiotic (GC/PrM) markers in ESCs, their functional relevance for the pluripotency and germ line commitment are largely unknown. In the present study, we used mouse as a model system and systematically analyzed the RNA and protein expression of GC/PrM markers in ESCs and found them to be comparable to the expression of cultured pluripotent cells originated from the germ line. Further, siRNA knockdown experiments have demonstrated the parallel maintenance and independence of pluripotent and GC/PrM networks in ESCs. Through chromatin immunoprecipitation experiments, we observed that pluripotent cells exhibit active chromatin states at GC marker genes and a bivalent chromatin structure at PrM marker genes. Moreover, gene expression analysis during the time course of iPS cells generation revealed that the expression of GC markers precedes pluripotency markers. Collectively, through our observations we hypothesize that the chromatin state and the expression of GC/PrM markers might indicate molecular parallels between in-vivo germ cell specification and pluripotent stem cell generation."],["dc.identifier.doi","10.1371/journal.pone.0022413"],["dc.identifier.isi","000293172900028"],["dc.identifier.pmid","21799849"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/8198"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22620"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Public Library Science"],["dc.relation.issn","1932-6203"],["dc.rights","CC BY 2.5"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.5"],["dc.title","Stage-Specific Germ-Cell Marker Genes Are Expressed in All Mouse Pluripotent Cell Types and Emerge Early during Induced Pluripotency"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","6008"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Nature Communications"],["dc.bibliographiccitation.lastpage","11"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Xu, Xingbo"],["dc.contributor.author","Smorag, Lukasz"],["dc.contributor.author","Nakamura, Toshinobu"],["dc.contributor.author","Kimura, Tohru"],["dc.contributor.author","Dressel, Ralf"],["dc.contributor.author","Fitzner, Antje"],["dc.contributor.author","Tan, Xiaoying"],["dc.contributor.author","Linke, Matthias"],["dc.contributor.author","Zechner, Ulrich"],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Pantakani, D.V. Krishna"],["dc.date.accessioned","2018-11-07T10:03:46Z"],["dc.date.available","2018-11-07T10:03:46Z"],["dc.date.issued","2015"],["dc.description.abstract","Reprogramming of mouse somatic cells into induced pluripotent stem cells (iPSCs) often generates partially reprogrammed iPSCs (pre-iPSCs), low-grade chimera forming iPSCs (lg-iPSCs) and fully reprogrammed, high-grade chimera production competent iPSCs (hg-iPSCs). Lg-iPSC transcriptome analysis revealed misregulated Dlk1-Dio3 cluster gene expression and subsequently the imprinting defect at the Dlk1-Dio3 locus. Here, we show that germ-cell marker Dppa3 is present only in lg-iPSCs and hg-iPSCs, and that induction with exogenous Dppa3 enhances reprogramming kinetics, generating all hg-iPSCs, similar to vitamin C (Vc). Conversely, Dppa3-null fibroblasts show reprogramming block at pre-iPSCs state and Dlk1-Dio3 imprinting defect. At the molecular level, we show that Dppa3 is associated with Dlk1-Dio3 locus and identify that Dppa3 maintains imprinting by antagonizing Dnmt3a binding. Our results further show molecular parallels between Dppa3 and Vc in Dlk1-Dio3 imprinting maintenance and suggest that early activation of Dppa3 is one of the cascades through which Vc facilitates the generation of fully reprogrammed iPSCs."],["dc.identifier.doi","10.1038/ncomms7008"],["dc.identifier.isi","000348812400009"],["dc.identifier.pmid","25613421"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11863"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38545"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/130"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C05: Bedeutung von zellulären Immunreaktionen für das kardiale Remodeling und die Therapie der Herzinsuffizienz durch Stammzelltransplantation"],["dc.relation.issn","2041-1723"],["dc.relation.workinggroup","RG Dressel"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Dppa3 expression is critical for generation of fully reprogrammed iPS cells and maintenance of Dlk1-Dio3 imprinting"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","677"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Biology of the Cell"],["dc.bibliographiccitation.lastpage","692"],["dc.bibliographiccitation.volume","104"],["dc.contributor.author","Smorag, Lukasz"],["dc.contributor.author","Zheng, Y."],["dc.contributor.author","Nolte, Jessica"],["dc.contributor.author","Zechner, Ulrich"],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.date.accessioned","2018-11-07T09:04:07Z"],["dc.date.available","2018-11-07T09:04:07Z"],["dc.date.issued","2012"],["dc.description.abstract","Background information Recently, it became apparent that microRNAs (miRNAs) can regulate gene expression post-transcriptionally. Despite the advances in identifying the testis-expressed miRNAs and their role in spermatogenesis, only few data are available showing the spatiotemporal expression of miRNAs during this process. Results To understand how different miRNAs can regulate germ cells differentiation, we generated a transgenic mouse model and purified pure populations of premeiotic (PrM) cells and primary spermatocytes (meiotic cells). We also established spermatogonial stem cell (SSC) culture using relatively simple and robust culture conditions. Comparison of global miRNA expression in these germ cell populations revealed 17 SSC-, 11 PrM- and 13 meiotic-specific miRNAs. We identified nine miRNAs as specific for both SSC and PrM cells and another nine miRNAs as specific for PrM and meiotic cells. Additionally, 45 miRNAs were identified as commonly expressed in all three cell types. Several of PrM- and meiotic-specific miRNAs were identified as exclusively/preferentially expressed in testis. We were able to identify the relevant target genes for many of these miRNAs. The luciferase reporter assays with SSC (miR-221)-, PrM (miR-203)- and meiotic (miR-34b-5p)-specific miRNAs and 3'-untranslated region constructs of their targets, c-Kit, Rbm44 and Cdk6, respectively, showed an approximately 30%40% decrease in reporter activity. Moreover, we observed a reduced expression of endogenous proteins, c-Kit and Cdk6, when the testis-derived cell lines, GC-1 and GC-4, were transfected with miRNA mimics for miR-221 and miR-34b-5p, respectively. Conclusions Taken together, we established the miRNA signature of SSC, PrM and meiotic cells and show evidence for their functional relevance during the process of spermatogenesis by target prediction and validation. Through our observations, we propose a working model in which the stage-specific miRNAs such as miR-221, -203 and -34b-5p coordinate the regulation of spermatogenesis."],["dc.identifier.doi","10.1111/boc.201200014"],["dc.identifier.isi","000310391100006"],["dc.identifier.pmid","22909339"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9536"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/25040"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1768-322X"],["dc.relation.issn","0248-4900"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","MicroRNA signature in various cell types of mouse spermatogenesis: Evidence for stage-specifically expressed miRNA-221, -203 and -34b-5p mediated spermatogenesis regulation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]