Sumario:
The International Journal of Developmental Biology
Linking Development, Stem Cells and Cancer Research
Euskal Herriko Unibertsitateko Argitalpen Zerbitzua / Servicio Editorial de la Universidad del País Vasco / University of the Basque Country Press
Volume 57 - Number 9/10 (2013) Editor-in-Chief: Juan Aréchaga
MORE INFORMATION [Abstract - FullText / FullText Open Access]
ISSN: 0214-6282 / ISSN-e: 1696-3547 www.intjdevbiol.com
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CONTENTS + ABSTRACTS
Reviews
Signaling pathways dictating pluripotency in embryonic stem cells
Debasree Dutta
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 667-675
Connecting epithelial polarity, proliferation and cancer in Drosophila: the many faces of lgl loss of function
Daniela Grifoni, Francesca Froldi and Annalisa Pession
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 677-687
Developmental control of cortico-cerebral astrogenesis
Antonello Mallamaci
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 689-706
Unraveling new roles for serotonin receptor 2B in development: key findings from Xenopus
Michela Ori, Stefania De Lucchini, Giulia Marras and Irma Nardi
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 707-714
Original Articles
Long-term serial cultivation of mouse induced pluripotent stem cells in serum-free and feeder-free defined medium
Sachiko Yamasaki, Kou Nabeshima, Yusuke Sotomaru, Yuki Taguchi, Hanae Mukasa, Miho K. Furue, J. Denry Sato and Tetsuji Okamoto
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 715-724
The Pou5f1 distal enhancer is sufficient to drive Pou5f1 promoter-EGFP expression in embryonic stem cells
Ji Liao, Yikun He and Piroska E. Szabó
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 725-729
Ontogenetic consequences of dysgenic crosses in Drosophila virilis
Marina I. Sokolova, Elena S. Zelentsova, Natalia G. Shostak, Nikolay V. Rozhkov and Michael B. Evgen’ev
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 731-739
Pitx3 directly regulates Foxe3 during early lens development
Nafees Ahmad, Muhammad Aslam, Doris Muenster, Marion Horsch, Muhammad A. Khan, Peter Carlsson, Johannes Beckers and Jochen Graw
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 741-751
Short Communication
Clonal analyses in the anterior pre-placodal region: implications for the early lineage bias of placodal progenitors
Sujata Bhattacharyya and Marianne E. Bronner
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 753-757
Developmental Expression Patterns
Eph receptors and ephrin class B ligands are expressed at tissue boundaries in Hydra vulgaris
Susanne Tischer, Mona Reineck, Johannes Söding, Sandra Münder and Angelika Böttger
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 759-765
Identification of promoter elements responsible for gonad-specific expression of zebrafish Deadend and its application to ovarian germ cell derivation
Ten-Tsao Wong, Abraham Tesfamichael and Paul Collodi
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 767-772
Zfyve9a regulates the proliferation of hepatic cells during zebrafish embryogenesis
Nian Liu, Zhuo Li, Duanqing Pei and Xiaodong Shu
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 773-778
Xnr3 affects brain patterning via cell migration in the neural-epidermal tissue boundary during early Xenopus embryogenesis
Mariko Morita, Satoshi Yamashita, Shinya Matsukawa, Yoshikazu Haramoto, Shuji Takahashi, Makoto Asashima and Tatsuo Michiue
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 779-786
Kidins220/ARMS is dynamically expressed during Xenopus laevis development
Silvia Marracci, Marianna Giannini, Marianna Vitiello, Massimiliano Andreazzoli and Luciana Dente
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 787-792
Analysis of Cripto expression during mouse cardiac myocyte differentiation
Jiu-Zhen Jin, Min Tan and Jixiang Ding
EHU/UPV/UBC - The International Journal of Developmental Biology (2013) 57: 793-797
The International Journal of Developmental Biology
ISSN 1696-3547 (online) and 0214-6282 (print)
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ABSTRACTS
Reviews
EHU/UPV/UBC - The International Journal of Developmental Biology 57: 667-675 (2013)
doi: 10.1387/ijdb.130064dd / © UBC Press (www.a360grados.net)
Signaling pathways dictating pluripotency in embryonic stem cells
Debasree Dutta
Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Kerala, India
Abstract: Embryonic Stem Cells (ESCs) are derived from the inner cell mass of blastocysts. They have the unique potency to differentiate into diverse lineages. Hence, they are bestowed with the term pluripotency. Several mechanisms have been implicated in maintaining the pluripotency of ESCs. This review will focus on the role of signaling pathways in regulating ESC pluripotency among diverse mammalian species. A novel phylogenetic approach has been designed to understand the structural basis of divergence in the signaling pathways which modulate pluripotency among different species. Detailed insight into different signaling mechanisms indicates inhibition of Extracellular Related Kinase 1/2 (ERK 1/2) signaling as the key component regulating the pluripotency of ESCs. On the basis of recent advances made in this field, it can be hypothesized that expression of the transcription factor KLF4 and inhibition of ERK signaling may promote the establishment and maintenance of true ESCs from different mammalian species.
Keywords: blastocyst, embryonic stem cell, signaling pathway, ERK, KLF4
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 677-687 (2013)
doi: 10.1387/ijdb.130285dg / © UBC Press (www.a360grados.net)
Connecting epithelial polarity, proliferation and cancer in Drosophila: the many faces of lgl loss of function
Daniela Grifoni, Francesca Froldi and Annalisa Pession
Dipartimento di Farmacia e Biotecnologie, University of Bologna, Italy
Abstract: Loss of cell polarity is a prominent feature of epithelial cancers. Several tumour-suppressor genes are indeed involved in establishing and maintaining a correct apical-basal polarity suggesting that a link exists between disruption of epithelial polarity and the control of cell proliferation. Nevertheless, the molecular basis of this link is only beginning to be unveiled. In Drosophila, the tumour suppressor gene lethal giant larvae (lgl) is widely used as a genetic tool in cancer modelling: its loss of function causes neoplastic growth of the imaginal tissues, larval epithelial organs from which adult structures originate. These mutant epithelia are characterised by loss of cell polarity and tissue architecture as well as hyperproliferation. We observed that in a clonal context, the ability of lgl mutant cells to express their neoplastic potential correlates with the levels of the oncoprotein Myc, a master regulator of cell growth and proliferation. Malignant, polarity-deficient mutant cells upregulate Myc and are able to overcome the tumour-suppressive defences imposed by the surrounding wild-type tissue. How does the loss of lgl function induce an increase in Myc levels? The answer to this question came from the finding that Lgl is an upstream regulator of the Hippo pathway, a highly conserved signalling network that controls proliferation of epithelial cells and organ size. The core of this pathway responds to several upstream regulators and converges on the inhibition of a transcriptional co-factor, Yorkie, which, as we and others have shown, is a direct regulator of the myc promoter. In this review we discuss the key findings that contributed to the identification of this regulatory network that links cell polarity to cell proliferation control.
Keywords: Drosophila, cell competition, Myc, Lgl, cancer
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 689-706 (2013)
doi: 10.1387/ijdb.130148am / © UBC Press (www.a360grados.net)
Developmental control of cortico-cerebral astrogenesis
Antonello Mallamaci
SISSA, Trieste, Italy
Abstract: A remarkable body of research over the last 15 years has been aimed at disentangling the cellular and molecular mechanisms which regulate murine cortico-cerebral astrogenesis. This research effort has allowed the reconstruction of the actual sizing of this process, as well as a better definition of its temporal, spatial and clonal articulation. Moreover, these investigations have shed substantial light on the cardinal molecular mechanisms governing the transition from pallial neuronogenesis to astrogenesis, as well as subsequent progress of the latter. It has turned out that proper temporal articulation of astrogenesis relies on a plethora of tightly interlaced mechanisms, which synergistically dampen astrogenesis prior to birth and promote it during peri- and postnatal life. The aim of this review is to provide a comprehensive and organic synthesis of these mechanisms, as well as a critical evaluation of their specific relevance to proper articulation of cerebral cortex astrogenesis in time and space.
Keywords: cerebral cortex, astrocyte, development, molecular mechanism, chromatin
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 707-714 (2013)
doi: 10.1387/ijdb.130204mo / © UBC Press (www.a360grados.net)
Unraveling new roles for serotonin receptor 2B in development: key findings from Xenopus
Michela Ori 1, Stefania De Lucchini 2, Giulia Marras 1 and Irma Nardi 1
1. Unitŕ di Biologia Cellulare e dello Sviluppo, Dipartimento di Biologia, Universitŕ di Pisa
2. Scuola Normale Superiore di Pisa, Pisa, Italy
Abstract: The serotonin receptor 5-HT2B has been shown to be critically important during embryogenesis as the knockout of this gene in mice causes heart defects and embryonic lethality that impairs further analyses on other embryonic cell and tissue types. In the present review, we highlight how the use of Xenopus laevis, an alternative vertebrate model suitable for gene loss and gain of function analyses, has contributed to our understanding of the role of 5-HT2B signaling during development. In vivo studies showed that 5-HT2B signaling is not only required for heart development, but that it also has a crucial role in ocular and craniofacial morphogenesis, being involved in shaping the first branchial arch and the jaw joint, in retinogenesis and possibly in periocular mesenchyme development. These findings may be relevant for our understanding of congenital defects including human birth malformations. In addition, 5-HT2B appears to be required for the therapeutic actions of selective serotonin reuptake inhibitors commonly prescribed as antidepressant drugs to pregnant and lactating women. We discuss how the understanding of the molecular basis of serotonin signaling in a suitable animal embryogenesis model may open new lines of investigations and therapies in humans.
Keywords: 5-HT2B, neural crest cell, eye, craniofacial morphogenesis, SSRI
Original Articles ---------------------------------------------------------
EHU/UPV/UBC - The International Journal of Developmental Biology 57: 715-724 (2013)
doi: 10.1387/ijdb.130173to / © UBC Press (www.a360grados.net)
Long-term serial cultivation of mouse induced pluripotent stem cells in serum-free and feeder-free defined medium
Sachiko Yamasaki 1, Kou Nabeshima 1, Yusuke Sotomaru 2, Yuki Taguchi 3, Hanae Mukasa 3, Miho K. Furue 4, J. Denry Sato 5 and Tetsuji Okamoto 1
1. Department of Molecular Oral Medicine and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University
2. Natural Science Center for Basic Research and Development, Hiroshima University
3. Department of Molecular Oral Medicine and Maxillofacial Surgery, Division of Frontier Medical Sciences, Graduate School of Biomedical & Health Sciences, Hiroshima University
4. Laboratory of Stem Cell Cultures, Department of Disease Bioresources Research, National Institute of Biomedical Innovation, Manzoni Project, Hiroshima, Japan
5. Manzanar Project Foundation, Wenham, MA, USA
Abstract: Mouse embryonic stem (mES) cells and mouse induced pluripotent stem (miPS) cells are commonly maintained on inactivated mouse embryonic fibroblast feeder cells in medium supplemented with fetal bovine serum or proprietary replacements. An undefined medium containing unknown quantities of reagents has limited the development of applications for pluripotent cells because of the relative lack of knowledge regarding cell responses to differentiating growth factors. Therefore we developed a serum-free medium, designated ESF7, in which mES cells can be maintained in an undifferentiated state without feeder cells. The medium was tested for culturing miPS cells. The miPS cells have been maintained in ESF7 medium for more than 3 years with an undifferentiated phenotype manifested by the expression of pluripotency marker genes and alkaline phosphatase, and these cells exhibited largely normal karyotypes. Furthermore, we found that fibroblast growth factor-2 (FGF-2) with heparin induced miPS cell differentiation into neuronal cells, both in an adherent monolayer and in embryoid body suspension culture. Moreover, we found that FGF-2 with bone morphogenetic protein 2 induced miPS cell differentiation into cardiomyocytes in embryoid body suspension culture. Furthermore, we transplanted subcutaneously miPS cells maintained in ESF7 into the dorsal flanks of SCID mice; all of the transplants produced tumors with tissues derived from all three embryonic germ layers. As this simple serum-free adherent monoculture system supports the long-term propagation of pluripotent iPS cells in vitro, it will allow us to elucidate cell responses to growth factors under defined conditions, and it should provide useful information for differentiation protocols for human iPS cells.
Keywords: iPS cell, serum-free, LIF, neural differentiation, cardiomyocyte
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 725-729 (2013)
doi: 10.1387/ijdb.120186ps / © UBC Press (www.a360grados.net)
The Pou5f1 distal enhancer is sufficient to drive Pou5f1 promoter-EGFP expression in embryonic stem cells
Ji Liao 1,2, Yikun He 1 and Piroska E. Szabó 2
1. College of Life Sciences, Capital Normal University, Beijing, P.R. China
2. Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope, Duarte, CA, USA
Abstract: The POU5F1 transcription factor is the gatekeeper of the pluripotent state in mammals. It is essential for epigenetic reprogramming events and also for germ cell viability. Pou5f1 gene expression is tightly controlled during embryogenesis, but its regulatory regions are not fully deciphered. The GOF18ΔPE-EGFP transgene, harboring the enhanced green fluorescence protein reporter gene inserted into a 17- kilobase long mouse Pou5f1 genomic sequence, has been widely used to visualize pluripotent embryonic cells and primordial germ cells in the mouse and other mammalian species. This construct includes the Pou5f1 promoter under the control of the distal enhancer and also includes the Pou5f1 gene body and flanking sequences. In search of the essential regulatory regions of Pou5f1, we generated four shorter forms of this construct. We found that the shortest form, containing the Pou5f1 promoter and distal enhancer but lacking the gene body and upstream flanking sequences, correctly expressed EGFP in transiently transformed undifferentiated ES cells, correctly switched it off upon ES cell differentiation, and correctly kept it silenced in differentiated Hep3B cells. Similarly to the original GOF18ΔPE-EGFP, this shortest form was expressed in the fetal mouse gonad. Our data suggest that the Pou5f1 distal enhancer and proximal promoter may be sufficient to specify transgene expression in pluripotent cells.
Keywords: Pou5f1, Oct4, EGFP transgene, pluripotency
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 731-739 (2013)
doi: 10.1387/ijdb.120189me / © UBC Press (www.a360grados.net)
Ontogenetic consequences of dysgenic crosses in Drosophila virilis
Marina I. Sokolova 1, Elena S. Zelentsova 1, Natalia G. Shostak 1, Nikolay V. Rozhkov 3 and Michael B. Evgen’ev 1,2
1. Engelhardt Institute of Molecular Biology, Moscow, Russia
2. Institute of Cell Biophysics, RAS, Pushchino, Moscow region, Russia
3. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
Abstract: Hybrid dysgenesis (HD) syndrome in Drosophila virilis presumably results from the mobilization of several unrelated mobile genetic elements in dysgenic hybrids. Morphogenetic events during oogenesis and spermatogenesis were investigated in detail in the progeny of D. virilis dysgenic crosses. Using germ-cell specific anti-Vasa staining, we monitored the fate of germline cells at different ontogenetic stages in strains of D. virilis and their hybrids. Anti-Vasa staining indicated that the major loss of pole cells occurs in dysgenic embryos at stage 11-14 after primordial germ cells (PGC) pass the midgut wall. At later ontogenetic stages, including larvae, pupae and imagoes, we often observed an abnormal development of gonads in dysgenic individuals with a frequent occurrence of unilateral and bilateral gonadal atrophy. Dysgenic females were characterized by the presence of various sterile ovarian phenotypes that predominantly include agametic ovarioles, while other atypical forms such as tumor-like ovarioles and dorsalized ovariolar follicles may also be present. Testis abnormalities were also frequently observed in dysgenic males. The sterility manifestations depended on the strain, the growing temperature and the age of the flies used in crosses. The observed gonadal sterility and other HD manifestations correlated with the absence of maternal piRNAs homologous to Penelope and other transposons in the early dysgenic embryos. We speculate that gonadal abnormalities mimicking several known sterility mutations probably result from the disturbance of developmental gene expression machinery due to the activation of unrelated families of transposons in early dysgenic embryos.
Keywords: Drosophila virilis, anti-Vasa staining, sterility, hybrid dysgenesis, transposon
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 741-751 (2013)
doi: 10.1387/ijdb.130193jg / © UBC Press (www.a360grados.net)
Pitx3 directly regulates Foxe3 during early lens development
Nafees Ahmad 1, Muhammad Aslam 2, Doris Muenster 1, Marion Horsch 3, Muhammad A. Khan 1, Peter Carlsson 4, Johannes Beckers 3,5 and Jochen Graw 1
Helmholtz Center Munich
1. Institute of Developmental Genetics
3. Institute of Experimental Genetics, Neuherberg, Germany
2. German Center for Neurodegenerative Diseases, Bonn, Germany
4. Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
5. Chair of Experimental Genetics, Technical University Munich, Freising-Weihenstephan, Germany.
Abstract: Pitx3 is a bicoid-related homeodomain transcription factor critical for the development of the ocular lens, mesencephalic dopaminergic neurons and skeletal muscle. In humans, mutations in PITX3 are responsible for cataracts and anterior segment abnormalities of varying degree; polymorphisms are associated with Parkinson’s disease. In aphakia (ak) mice, two deletions in the promoter region of Pitx3 cause abnormal lens development. Here, we investigated systematically the role of Pitx3 in lens development including its molecular targets responsible for the ak phenotype. We have shown that ak lenses exhibit reduced proliferation and aberrant fiber cell differentiation. This was associated with loss of Foxe3 expression, complete absence of Prox1 expression, reduced expression of epsilon-tubulin and earlier expression of gamma-crystallin during lens development. Using EMSA and ChIP assays, we demonstrated that Pitx3 binds to an evolutionary conserved bicoid-binding site on the 5’-upstream region of Foxe3. Finally, Pitx3 binding to 5’-upstream region of Foxe3 increased transcriptional activity significantly in a cell-based reporter assay. Identification of Foxe3 as a transcriptional target of Pitx3 explains at least in part some of the phenotypic similarities of the ak and dyl mice (dysgenic lens, a Foxe3 allele). These findings enhance our understanding of the molecular cascades which subserve lens development.
Keywords: Pitx3, aphakia, lens development, Prox1, Foxe3
Short Communication ---------------------------------------------------
EHU/UPV/UBC - The International Journal of Developmental Biology 57: 753-757 (2013)
doi: 10.1387/ijdb.130155mb / © UBC Press (www.a360grados.net)
Clonal analyses in the anterior pre-placodal region: implications for the early lineage bias of placodal progenitors
Sujata Bhattacharyya and Marianne E. Bronner
Division of Biology, California Institute of Technology, Pasadena, CA, USA
Abstract: Cranial ectodermal placodes, a vertebrate innovation, contribute to the adenohypophysis and peripheral nervous system of the head, including the paired sense organs (eyes, nose, ears) and sensory ganglia of the Vth, VIIth, IXth and Xth cranial nerves. Fate-maps of groups of cells in amphibians, teleosts and amniotes have demonstrated that all placodes have a common origin in a horseshoe shaped territory, known as the preplacodal region (PPR), which surrounds the presumptive neural plate of the late gastrula/early neurula stage embryo. Given the extensive regional overlap of progenitors for different placodes in the chick embryo, it has been a matter of debate as to whether individual cells in the PPR are truly multipotent progenitors, with regard to placodal identity, or rather are lineage-biased or restricted to a specific placodal type prior to overt differentiation. Utilizing clonal analyses in vivo, we demonstrate here that the anterior PPR comprises some precursors that contribute either to the olfactory or lens placode well before they are spatially segregated or committed to either of these placodal fates. This suggests that lineage bias towards a specific placodal fate may coincide with induction of the PPR.
Keywords: placode, olfactory, lens, pre-placodal region, lineage
Developmental Expression Patterns -------------------------------------
EHU/UPV/UBC - The International Journal of Developmental Biology 57: 759-765 (2013)
doi: 10.1387/ijdb.130158ab / © UBC Press (www.a360grados.net)
Eph receptors and ephrin class B ligands are expressed at tissue boundaries in Hydra vulgaris
Susanne Tischer 1, Mona Reineck 1, Johannes Söding 2, Sandra Münder 1 and Angelika Böttger 1
1. Department of Biology 2, Ludwig-Maximilians-Universität München
2. Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
Abstract: Eph receptors and ephrins are important players in axon guidance, cell sorting and boundary formation. Both the receptors and the ligands are integrated transmembrane proteins and signalling is bidirectional. The prevalent outcome of signal transduction is repulsion of adjacent cells or cell populations. Eph/ephrins have been identified in all multicellular animals from human to sponge, their functions however appear to have been altered during evolution. Here we have identified four Eph receptors and three class B ligands in the cnidarian Hydra vulgaris, indicating that those are the evolutionary older ones. In situ hybridisation experiments revealed a striking complementarity of expression of receptors and ligands in tentacles and in developing buds. This suggests that the original function of ephrin signalling may have been in epithelial cell adhesion and the formation of tissue boundaries.
Keywords: Eph-receptor, ephrin, hydra, boundaries, phylogeny
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 767-772 (2013)
doi: 10.1387/ijdb.120234tw / © UBC Press (www.a360grados.net)
Identification of promoter elements responsible for gonad-specific expression of zebrafish Deadend and its application to ovarian germ cell derivation
Ten-Tsao Wong, Abraham Tesfamichael and Paul Collodi
Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
Abstract: We discovered that a 150-bp region of zebrafish deadend (dnd) spanning the translation start codon, exon 1 and part of intron 1 is required to direct heterologous neomycin-resistance gene (neo) expression specifically in the gonad, similar to endogenous dnd. Using an 8.3-kb dnd promoter that contains this 150-bp region, we generated Tg(dnd:neo-dnd) transgenic zebrafish in which the expression of Neo was detected specifically in ovarian germ cells. The transgenic fish were used to initiate primary ovarian germ cell cultures with antibiotic G418 to select ovarian germ cells and eliminate ovarian somatic cells. RT-PCR results demonstrated that the drug-selected ovarian germ cells continued to express germ-cell markers nanos3, vasa and dnd. Growth assays demonstrated that recombinant zebrafish Lif had a significant mitogenic effect on the ovarian germ cells. When long-term ovarian germ cell cultures were transplanted into two-week-old infertile larvae, they successfully colonized and directed the formation of a truncated gonad in the recipient adult fish. Histological examination of the recipient adult fish revealed that 9 out of 34 individuals (26%) possessed donor-derived cells in their gonads. The identification of zebrafish dnd promoter and the use of this promoter to generate Tg(dnd:neo-dnd) led to the success of germ cell isolation through drug selection to generate homogenous germ cells that can be used to study zebrafish germ cell biology and may lead to a cell-mediated gene transfer strategy.
Keywords: zebrafish, deadend, ovarian germ cell, transplantation
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 773-778 (2013)
doi: 10.1387/ijdb.130065xs / © UBC Press (www.a360grados.net)
Zfyve9a regulates the proliferation of hepatic cells during zebrafish embryogenesis
Nian Liu, Zhuo Li, Duanqing Pei and Xiaodong Shu
Key Laboratory of Regenerative Biology, Chinese Academy of Sciences, and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Guangzhou, China.
Abstract: Zfyve9 is a FYVE domain protein first identified as a binding partner for SMAD2/3. In vitro studies indicate that it can function either positively or negatively in the TGF-beta signaling pathway depending on the cell lines used. However, the in vivo function of this protein remains to be investigated. We first analyzed the tissue distribution of zebrafish zfyve9a by in situ hybridization. To investigate the in vivo function of this gene, we performed morpholino mediated loss-of-function assays. We analyzed the expression patterns of liver (cp and fabp10a), pancreas (trypsin and insulin) or gut (fabp2) specific markers to determine whether the formation of these organs is affected by zfyve9a knockdown. We determined the specification of hepatoblast in the zfyve9a morphants (prox1a) and investigated the proliferation and survival of hepatic cells in the morphants by P-H3 staining and TUNEL assay respectively. We report here that zfyve9a is enriched in the zebrafish embryonic liver and required for hepatogenesis. Morpholino mediated knockdown of zfyve9a inhibits the formation of liver by day 4 while the other endoderm-derived organs appear unaffected. We demonstrated that the specification of hepatoblasts is normal in the zfyve9a morphants; however, the proliferation rate of these cells is reduced. Thus, our results reveal the liver-specific function of zfyve9a during early embryogenesis and indicate that the zfyve9a mediated signal is essential for the proliferation of hepatic cells during the expansion of liver bud.
Keywords: zfyve9a, liver development, proliferation, zebrafish
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 779-786 (2013)
doi: 10.1387/ijdb.130161tm / © UBC Press (www.a360grados.net)
Xnr3 affects brain patterning via cell migration in the neural-epidermal tissue boundary during early Xenopus embryogenesis
Mariko Morita 1, Satoshi Yamashita 1, Shinya Matsukawa 1, Yoshikazu Haramoto 2, Shuji Takahashi 3, Makoto Asashima 1,2 and Tatsuo Michiue 1
1. Department of Life Sciences, Graduate School of Arts and Sciences, the University of Tokyo, Tokyo, Japan
2. Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
3. Komaba Organization for Educational Excellence, Graduate School of Arts and Sciences, the University of Tokyo, Tokyo, Japan.
Abstract: Neural induction and anteroposterior neural patterning occur simultaneously during Xenopus gastrulation by the inhibition of BMP and Wnt signaling, respectively. However, other processes might be necessary for determining the neural-epidermal boundary. Xenopus nodal-related-3 (Xnr3) is expressed in dorsal blastula and plays a role in neural formation. In this study, we analyzed how Xnr3 affects neural patterning to identify novel mechanisms of neural-epidermal-boundary determination. In situ hybridization revealed that ventro-animal injection with Xnr3 shifted the lateral krox20 expression domain anteriorly and reduced Otx2 expression. The mature region of Xnr3 is necessary for these effects to occur, and the pro-region accelerated them. Phalloidin labeling revealed that cells around the neural-epidermal boundary lost their slender shape following Xnr3 injection. Moreover, we analyzed the cell migration of ectodermal cells and found specific Xnr3-induced effects at the neural-epidermal boundary. These findings together suggested that Xnr3 affects anterior ectoderm migration around the neural-epidermal boundary to induce a specific neural pattern abnormality. Change of the shape of surrounding ectodermal cells and the specific migratory pattern might therefore reflect the novel mechanism of neural-epidermal boundary.
Keywords: Xenopus, Xnr3, neural-epidermal boundary, ectoderm, neural patterning, cell migration
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 787-792 (2013)
doi: 10.1387/ijdb.130080sm / © UBC Press (www.a360grados.net)
Kidins220/ARMS is dynamically expressed during Xenopus laevis development
Silvia Marracci, Marianna Giannini, Marianna Vitiello, Massimiliano Andreazzoli and Luciana Dente
Department of Biology, University of Pisa, Pisa, Italy
Abstract: Kidins220 (Kinase D interacting substrate of 220 kDa)/ARMS (Ankyrin Repeat-rich Membrane Spanning) is a conserved scaffold protein that acts as a downstream substrate for protein kinase D and mediates multiple receptor signalling pathways. Despite the dissecting of the function of this protein in mammals, using both in vitro and in vivo studies, a detailed characterization of its gene expression during early phases of embryogenesis has not been described yet. Here, we have used Xenopus laevis as a vertebrate model system to analyze the gene expression and the protein localization of Kidins220/ARMS. We found its expression was dynamically regulated during development. Kidins220/ARMS mRNA was expressed from neurula to larval stage in different embryonic regions including the nervous system, eye, branchial arches, heart and somites. Similar to the transcript, the protein was present in multiple embryonic domains including the central nervous system, cranial nerves, motor nerves, intersomitic junctions, retinal ganglion cells, lens, otic vesicle, heart and branchial arches. In particular, in some regions such as the retina and somites, the protein displayed a differential localization pattern in stage 42 embryos when compared to the earlier examined stages. Taken together our results suggest that this multidomain protein is involved in distinct spatio-temporal differentiative events.
Keywords: PDZ binding protein, neural system, glial cell, intersomitic region, heart
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EHU/UPV/UBC - The International Journal of Developmental Biology 57: 793-797 (2013)
doi: 10.1387/ijdb.130072jd / © UBC Press (www.a360grados.net)
Analysis of Cripto expression during mouse cardiac myocyte differentiation
Jiu-Zhen Jin, Min Tan and Jixiang Ding
Department of Molecular, Cellular & Craniofacial Biology and Birth Defects Center, University of Louisville, Louisville, KY, USA
Abstract: Vertebrate cardiac progenitor cells are initially allocated in two distinct domains, the first and second heart fields. It has been demonstrated that first heart field cells give rise to the myocardial cells in the left ventricle and part of the atria, whereas second heart field cells move into the developing heart tube and contribute to the myocardium of the outflow tract and right ventricle and the majority of atria. In this study, we have examined the expression of the mouse Cripto gene and the lineage of Cripto-expressing cells, focusing on its relationship with cardiac myocyte differentiation. The mouse Cripto gene is initially expressed at late head fold (LHF) stages in the cardiac crescent region, known as the first heart field; later in the medial region of the early heart tube, and by embryonic day 8.5, it is localized to the outflow tract. Using a Cripto-LacZ allele, we found that Cripto- expressing progeny cells contribute to the myocardium of the entire outflow tract and right ventricle, as well as to a majority of cells within the left ventricle. In contrast, no Cripto- expressing progeny cells were found in the atria or atrio-ventricular canal. Therefore, Cripto is transiently expressed in early differentiating myocardial cells of the left ventricle, right ventricle and outflow tract between LHF stages and E8.5. Cripto expression is subsequently downregulated as cells undergo further differentiation.
Keywords: cripto, heart development, hear fields, myocyte differentiation
The International Journal of Developmental Biology
ISSN 1696-3547 (online) and 0214-6282 (print) |
