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Sample records for arabidopsis embryo requires

  1. Key divisions in the early Arabidopsis embryo require POL and PLL1 phosphatases to establish the root stem organizer and vascular axis

    OpenAIRE

    Song, Sang-Kee; Hofhuis, Hugo; Lee, Myeong Min; Clark, Steven E

    2008-01-01

    Arabidopsis development proceeds from three stem cell populations located at the shoot, flower and root meristems. The relationship between the highly related shoot and flower stem cells with the very divergent root stem cells has been unclear. We show that the related phosphatases POL and PLL1 are required for all three stem cell populations. pol pll1 mutant embryos lack key asymmetric divisions that give rise to the root stem cell organizer and the central vascular axis. Instead, these cell...

  2. YODA signalling in the early Arabidopsis embryo.

    Science.gov (United States)

    Musielak, Thomas J; Bayer, Martin

    2014-04-01

    During early embryogenesis, flowering plants establish their principal body plan starting with an apical-basal axis. An asymmetric division of the zygote gives rise to apical and basal cells with different developmental fates. Besides WOX (WUSCHEL-RELATED HOMEOBOX) transcription factors and the plant hormone auxin, the YDA (YODA)/MAPK (mitogen-activated protein kinase) pathway plays a major role in establishing different cell fates after the first zygotic division. In the present review, we summarize the available data on YDA signalling during embryogenesis. The role of YDA in other developmental processes was taken into account to highlight possible implications for this pathway in the embryo. PMID:24646252

  3. ABORTED GAMETOPHYTE 1 is required for gametogenesis in Arabidopsis.

    Science.gov (United States)

    Cui, Hong-Hui; Liao, Hong-Ze; Tang, Yu; Du, Xin-Yu; Chen, Li-Qun; Ye, De; Zhang, Xue-Qin

    2015-12-01

    In flowering plants, the male and female gametogenesis is a crucial step of sexual reproduction. Although many genes have been identified as being involved in the gametogenesis process, the genetic mechanisms underlying gametogenesis remains poorly understood. We reported here characterization of the gene, ABORTED GAMETOPHYTE 1 (AOG1) that is newly identified as essential for gametogenesis in Arabidopsis thaliana. AOG1 is expressed predominantly in reproductive tissues including the developing pollen grains and ovules. The AOG1 protein shares no significant amino acid sequence similarity with other documented proteins and is located mainly in nuclei of the cells. Mutation in AOG1 caused degeneration of pollen at the uninucleate microspore stage and severe defect in embryo sacs, leading to a significant reduction in male and female fertility. Furthermore, the molecular analyses showed that the aog1 mutant significantly affected the expression of several genes, which are required for gametogenesis. Our results suggest that AOG1 plays important roles in gametogenesis at the stage prior to pollen mitosis I (PMI) in Arabidopsis, possibly through collaboration with other genes. PMID:25693728

  4. Xyloglucan Metabolism Differentially Impacts the Cell Wall Characteristics of the Endosperm and Embryo during Arabidopsis Seed Germination.

    Science.gov (United States)

    Sechet, Julien; Frey, Anne; Effroy-Cuzzi, Delphine; Berger, Adeline; Perreau, François; Cueff, Gwendal; Charif, Delphine; Rajjou, Loïc; Mouille, Grégory; North, Helen M; Marion-Poll, Annie

    2016-03-01

    Cell wall remodeling is an essential mechanism for the regulation of plant growth and architecture, and xyloglucans (XyGs), the major hemicellulose, are often considered as spacers of cellulose microfibrils during growth. In the seed, the activity of cell wall enzymes plays a critical role in germination by enabling embryo cell expansion leading to radicle protrusion, as well as endosperm weakening prior to its rupture. A screen for Arabidopsis (Arabidopsis thaliana) mutants affected in the hormonal control of germination identified a mutant, xyl1, able to germinate on paclobutrazol, an inhibitor of gibberellin biosynthesis. This mutant also exhibited reduced dormancy and increased resistance to high temperature. The XYL1 locus encodes an α-xylosidase required for XyG maturation through the trimming of Xyl. The xyl1 mutant phenotypes were associated with modifications to endosperm cell wall composition that likely impact on its resistance, as further demonstrated by the restoration of normal germination characteristics by endosperm-specific XYL1 expression. The absence of phenotypes in mutants defective for other glycosidases, which trim Gal or Fuc, suggests that XYL1 plays the major role in this process. Finally, the decreased XyG abundance in hypocotyl longitudinal cell walls of germinating embryos indicates a potential role in cell wall loosening and anisotropic growth together with pectin de-methylesterification. PMID:26826221

  5. Physiological and morphological responses induced by α-particle radiation on Arabidopsis thaliana embryos.

    Science.gov (United States)

    Ren, J; Liu, L; Jin, X L; Fu, S L; Ding, Z C

    2014-01-01

    Alpha (α)-particle radiation has been thoroughly studied in the occupational and residential environments, but biological mechanisms induced by α-particle radiation on plants are not clearly understood. In this study, radiation effects were examined using different total doses (1, 10, 100 Gy, respectively) of 241Am, α-particle on Arabidopsis embryos. No significant difference in the germination percentage was observed between the 3 levels of doses and the control. Germination speed and root length were increased by treatment with the 1-Gy dose of a-particles, and decreased by treatment with 10- and 100-Gy doses. Moreover, the bending degree of roots increased with radiation dose, and the roots showed an "S" shape when treated with the 100-Gy dose. Root bending under the 100-Gy dose was inhibited by scavengers of reactive oxygen species (ROS). Root gravitropism and root length may respond to the consistency of ROS induced by irradiation. Further analysis of the physiological effects revealed that an increase in a-particle radiation intensity enhanced the activity of catalase and the content of malondialdehyde, but superoxide dismutase activity was reduced by treatment with 100-Gy radiation of a-particles, suggesting that the high linear energy transfer of a-particles may cause a relatively high level of membrane lipid preoxidation and high accumulation of ROS. ROS showed both physiological and morphological responses following exposure to α-particle radiation in Arabidopsis embryos. PMID:25501166

  6. Arabidopsis HD-Zip II transcription factors control apical embryo development and meristem function.

    Science.gov (United States)

    Turchi, Luana; Carabelli, Monica; Ruzza, Valentino; Possenti, Marco; Sassi, Massimiliano; Peñalosa, Andrés; Sessa, Giovanna; Salvi, Sergio; Forte, Valentina; Morelli, Giorgio; Ruberti, Ida

    2013-05-01

    The Arabidopsis genome encodes ten Homeodomain-Leucine zipper (HD-Zip) II proteins. ARABIDOPSIS THALIANA HOMEOBOX 2 (ATHB2), HOMEOBOX ARABIDOPSIS THALIANA 1 (HAT1), HAT2, HAT3 and ATHB4 are regulated by changes in the red/far red light ratio that induce shade avoidance in most of the angiosperms. Here, we show that progressive loss of HAT3, ATHB4 and ATHB2 activity causes developmental defects from embryogenesis onwards in white light. Cotyledon development and number are altered in hat3 athb4 embryos, and these defects correlate with changes in auxin distribution and response. athb2 gain-of-function mutation and ATHB2 expression driven by its promoter in hat3 athb4 result in significant attenuation of phenotypes, thus demonstrating that ATHB2 is functionally redundant to HAT3 and ATHB4. In analogy to loss-of-function mutations in HD-Zip III genes, loss of HAT3 and ATHB4 results in organ polarity defects, whereas triple hat3 athb4 athb2 mutants develop one or two radialized cotyledons and lack an active shoot apical meristem (SAM). Consistent with overlapping expression pattern of HD-Zip II and HD-Zip III gene family members, bilateral symmetry and SAM defects are enhanced when hat3 athb4 is combined with mutations in PHABULOSA (PHB), PHAVOLUTA (PHV) or REVOLUTA (REV). Finally, we show that ATHB2 is part of a complex regulatory circuit directly involving both HD-Zip II and HD-Zip III proteins. Taken together, our study provides evidence that a genetic system consisting of HD-Zip II and HD-Zip III genes cooperates in establishing bilateral symmetry and patterning along the adaxial-abaxial axis in the embryo as well as in controlling SAM activity. PMID:23578926

  7. Biological response of arabidopsis seed to MeV proton irradiation at different region of its embryo

    International Nuclear Information System (INIS)

    The water saturated Arabidopsis seeds were irradiated with protons in air. The ion energy is from 1.1 MeV to 6.5 MeV. According to TRIM simulation, the damaged region of the seed induced by the incident ions is near the surface region of the embryo, half of the embryo and the whole embryo, respectively. The protons with high energy can damage the shoot apical meristem (SAM) in the embryo while the protons with low energy cannot. The ion fluence used in this experiment was in the range of 4 x 109 to 1 x 1014 ions/cm2. The experimental results showed that both the germination and survival rates decrease while increasing ion fluence, and the fluence-response curve for different damaged region of the embryo has different characters. Besides SAM, which is generally considered as the main radiobiological target, the existence of a secondary target besides SAM is proposed in this paper. (authors)

  8. Dissection of Arabidopsis NCED9 promoter regulatory regions reveals a role for ABA synthesized in embryos in the regulation of GA-dependent seed germination.

    Science.gov (United States)

    Seo, Mitsunori; Kanno, Yuri; Frey, Anne; North, Helen M; Marion-Poll, Annie

    2016-05-01

    Nine-cis-epoxycarotenoid dioxygenase (NCED) catalyzes the key step of abscisic acid (ABA) biosynthesis. There are five genes encoding NCED in Arabidopsis, which differentially regulate ABA biosynthesis in a spatiotemporal manner in response to endogenous and environmental stimuli. Previous studies have shown that NCED9 is expressed in testa and embryos during seed development. In the present study, we have identified promoter regions required for the expression of NCED9 in testa and embryos, respectively. Electrophoretic mobility shift assays (EMSA) and yeast one-hybrid (Y1H) assays showed that several homeodomain-leucine zipper (HD-Zip) proteins, namely ATHBs, bound to the sequence required for expression of NCED9 in testa, suggesting that they redundantly regulate NCED9 expression. By expressing the NCED9 gene under the control of a deleted NCED9 promoter in an nced9 mutant expression was limited to embryos. Transformants were complemented for the paclobutrazol resistant germination phenotype of the mutant, suggesting that the ABA synthesis mediated by NCED9 in embryos plays an important role in the regulation of gibberellin (GA)-dependent seed germination. PMID:26993239

  9. Proline is required for male gametophyte development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Mattioli Roberto

    2012-12-01

    Full Text Available Abstract Background In crosses between the proline-deficient mutant homozygous for p5cs1 and heterozygous for p5cs2 (p5cs1 p5cs2/P5CS2, used as male, and different Arabidopsis mutants, used as females, the p5cs2 mutant allele was rarely transmitted to the outcrossed progeny, suggesting that the fertility of the male gametophyte carrying mutations in both P5CS1 and P5CS2 is severely compromised. Results To confirm the fertility defects of pollen from p5cs1 p5cs2/P5CS2 mutants, transmission of mutant alleles through pollen was tested in two ways. First, the number of progeny inheriting a dominant sulfadiazine resistance marker linked to p5cs2 was determined. Second, the number of p5cs2/p5cs2 embryos was determined. A ratio of resistant to susceptible plantlets close to 50%, and the absence of aborted embryos were consistent with the hypothesis that the male gametophyte carrying both p5cs1 and p5cs2 alleles is rarely transmitted to the offspring. In addition, in reciprocal crosses with wild type, about 50% of the p5cs2 mutant alleles were transmitted to the sporophytic generation when p5cs1 p5cs2/P5CS2 was used as a female, while less than 1% of the p5cs2 alleles could be transmitted to the outcrossed progeny when p5cs1 p5cs2/P5CS2 was used as a male. Morphological and functional analysis of mutant pollen revealed a population of small, degenerated, and unviable pollen grains, indicating that the mutant homozygous for p5cs1 and heterozygous for p5cs2 is impaired in pollen development, and suggesting a role for proline in male gametophyte development. Consistent with these findings, we found that pollen from p5cs1 homozygous mutants, display defects similar to, but less pronounced than pollen from p5cs1 p5cs2/P5CS2 mutants. Finally, we show that pollen from p5cs1 p5cs2/P5CS2 plants contains less proline than wild type and that exogenous proline supplied from the beginning of another development can partially complement both morphological and

  10. Requirement of proline synthesis during Arabidopsis reproductive development

    Directory of Open Access Journals (Sweden)

    Funck Dietmar

    2012-10-01

    Full Text Available Abstract Background Gamete and embryo development are crucial for successful reproduction and seed set in plants, which is often the determining factor for crop yield. Proline accumulation was largely viewed as a specific reaction to overcome stress conditions, while recent studies suggested important functions of proline metabolism also in reproductive development. Both the level of free proline and proline metabolism were proposed to influence the transition to flowering, as well as pollen and embryo development. Results In this study, we performed a detailed analysis of the contribution of individual proline biosynthetic enzymes to vegetative development and reproductive success in Arabidopsis. In contrast to previous reports, we found that pyrroline-5-carboxylate (P5C synthetase 2 (P5CS2 is not essential for sexual reproduction although p5cs2 mutant plants were retarded in vegetative development and displayed reduced fertility under long-day conditions. Single mutant plants devoid of P5CS1 did not show any developmental defects. Simultaneous absence of both P5CS isoforms resulted in pollen sterility, while fertile egg cells could still be produced. Expression of P5C reductase (P5CR was indispensable for embryo development but surprisingly not needed for pollen or egg cell fertility. The latter observation could be explained by an extreme stability of P5CR activity, which had a half-life time of greater than 3 weeks in vitro. Expression of P5CR-GFP under the control of the endogenous P5CR promoter was able to restore growth of homozygous p5cr mutant embryos. The analysis of P5CR-GFP-fluorescence in planta supported an exclusively cytoplasmatic localisation of P5CR. Conclusions Our results demonstrate that potential alternative pathways for proline synthesis or inter-generation transfer of proline are not sufficient to overcome a defect in proline biosynthesis from glutamate during pollen development. Proline biosynthesis through P5CS2 and P5

  11. The CA domain of the respiratory complex I is required for normal embryogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Córdoba, Juan Pablo; Marchetti, Fernanda; Soto, Débora; Martin, María Victoria; Pagnussat, Gabriela Carolina; Zabaleta, Eduardo

    2016-03-01

    The NADH-ubiquinone oxidoreductase [complex I (CI), EC 1.6.5.3] of the mitochondrial respiratory chain is the principal entry point of electrons, and vital in maintaining metabolism and the redox balance. In a variety of eukaryotic organisms, except animal and fungi (Opisthokonta), it contains an extra domain composed of putative gamma carbonic anhydrases subunits, named the CA domain, which was proposed to be essential for complex I assembly. There are two kinds of carbonic anhydrase subunits: CAs (of which there are three) and carbonic anhydrase-like proteins (CALs) (of which there are two). In plants, the CA domain has been linked to photorespiration. In this work, we report that Arabidopsis mutant plants affected in two specific CA subunits show a lethal phenotype. Double homozygous knockouts ca1ca2 embryos show a significant developmental delay compared to the non-homozygous embryos, which show a wild-type (WT) phenotype in the same silique. Mutant embryos show impaired mitochondrial membrane potential and mitochondrial reactive oxygen species (ROS) accumulation. The characteristic embryo greening does not take place and fewer but larger oil bodies are present. Although seeds look dark brown and wrinkled, they are able to germinate 12 d later than WT seeds. However, they die immediately, most likely due to oxidative stress.Since the CA domain is required for complex I biogenesis, it is predicted that in ca1ca2 mutants no complex I could be formed, triggering the lethal phenotype. The in vivo composition of a functional CA domain is proposed. PMID:26721503

  12. SPT6L Encoding a Putative WG/GW-Repeat Protein Regulates Apical-Basal Polarity of Embryo in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Lu Gu; Hua Wang; Hai Huang; Xiao-Feng Cui

    2012-01-01

    In eukaryotes,a protein motif consisting of WG/GW repeats,also called the Argonaute (AGO) hook,is thought to be essential for binding AGO proteins to fulfill their functions in RNA-mediated gene silencing.Although a number of WG/GW-containing proteins have been computationally identified in Arabidopsis,their roles in plant growth and development are unknown.Here,we show that the Arabidopsis Suppressor of Ty insertion 6-like (SPT6L) gene,which encodes a protein with C-terminal WG/GW repeats,plays critical roles in embryonic development.SPT6L is evolutionarily conserved only in vascular plants,with varying numbers of C-terminal WG/GW repeats,which are plant-species specific.spt61 mutants formed embryos with an aberrant apical-basal axis,showing insufficient development of the basal domain and embryonic lethality.Expression domains of the class-Ⅲ homeodomain-leucine zipper (HD-ZIP Ⅲ) genes PHABULOSA (PHB) and PHAVOLUTA (PHV) were expanded in the spt61 embryo.In contrast,the PLETHORA1 (PLT1) gene,which acts antagonistically to the HD-ZIP Ⅲ genes in specification of basal fate,was severely down-regulated in the spt61 mutant.Furthermore,the phb phv double mutations partially rescued aberrant basal development in the spt61 background and restored PLT1 expression.Collectively,our results indicate that SPT6L is essential for specification of the apical-basal axis,partly by controlling the HD-ZIP Ⅲ genes in embryos.

  13. Transcriptional activation of Arabidopsis axis patterning genes WOX8/9 links zygote polarity to embryo development.

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    Ueda, Minako; Zhang, Zhongjuan; Laux, Thomas

    2011-02-15

    In most flowering plants, the apical-basal body axis is established by an asymmetric division of the polarized zygote. In Arabidopsis, early embryo patterning is regulated by WOX homeobox genes, which are coexpressed in the zygote but become restricted to apical (WOX2) and basal (WOX8/9) cells. How the asymmetry of zygote division is regulated and connected to the daughter cell fates is largely unknown. Here, we show that expression of WOX8 is independent of the axis patterning signal auxin, but, together with the redundant gene WOX9, is activated in the zygote, its basal daughter cell, and the hypophysis by the zinc-finger transcription factor WRKY2. In wrky2 mutants, egg cells polarize normally but zygotes fail to reestablish polar organelle positioning from a transient symmetric state, resulting in equal cell division and distorted embryo development. Both defects are rescued by overexpressing WOX8, indicating that WRKY2-dependent WOX8 transcription links zygote polarization with embryo patterning. PMID:21316593

  14. The Arabidopsis MutS homolog AtMSH5 is required for normal meiosis

    Institute of Scientific and Technical Information of China (English)

    Xiaoduo Lu; Xiaolin Liu; Lizhe An; Wei Zhang; Jian Sun; Huijuan Pei; Hongyan Meng; Yunliu Fan; Chunyi Zhang

    2008-01-01

    MSH5,a member of the MutS homolog DNA mismatch repair protein family,has been shown to be required for proper homologous chromosome recombination in diverse organisms such as mouse,budding yeast and Caenorhabditis elegans.In this paper,we show that a mutant Arabidopsis plant carrying the putative disrupted AtMSH5 gene exhibits defects during meiotic division,producing a proportion of nonviable pollen grains and abnormal embryo sacs,and thereby leading to a decrease in fertility.AtMSH5 expression is confined to meiotic floral buds,which is consistent with a possible role during meiosis.Cytological analysis of male meiosis revealed the presence of numerous univalents from diplotene to metaphase I,which were associated with a great reduction in chiasma frequencies.The average number of residual chiasmata in the mutant is reduced to 2.54 per meiocyte,which accounts for~25% of the amount in the wild type.Here,quantitative cytogenetical analysis reveals that the residual chiasmata in Atmsh5 mutants are randomly distributed among meiocytes,suggesting that AtMSH5 has an essential role during interferencesensitive chiasma formation.Taken together,the evidence indicates that AtMSH5 promotes homologous recombination through facilitating chiasma formation during prophase I in Arabidopsis.

  15. Temporal and spatial requirement of EMF1 activity for Arabidopsis vegetative and reproductive development.

    Science.gov (United States)

    Sánchez, Rosario; Kim, Minjung Y; Calonje, Myriam; Moon, Yong-Hwan; Sung, Z Renee

    2009-07-01

    EMBRYONIC FLOWER (EMF) genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis. Removal of EMF gene function caused plants to flower upon germination, producing abnormal and sterile flowers. The pleiotropic effect of emf1 mutation suggests its requirement for gene programs involved in diverse developmental processes. Transgenic plants harboring EMF1 promoter::glucuronidase (GUS) reporter gene were generated to investigate the temporal and spatial expression pattern of EMF1. These plants displayed differential GUS activity in vegetative and flower tissues, consistent with the role of EMF1 in regulating multiple gene programs. EMF1::GUS expression pattern in emf mutants suggests organ-specific auto-regulation. Sense- and antisense (as) EMF1 cDNA were expressed under the control of stage- and tissue-specific promoters in transgenic plants. Characterization of these transgenic plants showed that EMF1 activity is required in meristematic as well as differentiating tissues to rescue emf mutant phenotype. Temporal removal or reduction of EMF1 activity in the embryo or shoot apex of wild-type seedlings was sufficient to cause early flowering and terminal flower formation in adult plants. Such reproductive cell memory is reflected in the flower MADS-box gene activity expressed prior to flowering in these early flowering plants. However, temporal removal of EMF1 activity in flower meristem did not affect flower development. Our results are consistent with EMF1's primary role in repressing flowering in order to allow for vegetative growth. PMID:19825645

  16. MOL1 is required for cambium homeostasis in Arabidopsis.

    Science.gov (United States)

    Gursanscky, Nial Rau; Jouannet, Virginie; Grünwald, Karin; Sanchez, Pablo; Laaber-Schwarz, Martina; Greb, Thomas

    2016-05-01

    Plants maintain pools of pluripotent stem cells which allow them to constantly produce new tissues and organs. Stem cell homeostasis in shoot and root tips depends on negative regulation by ligand-receptor pairs of the CLE peptide and leucine-rich repeat receptor-like kinase (LRR-RLK) families. However, regulation of the cambium, the stem cell niche required for lateral growth of shoots and roots, is poorly characterized. Here we show that the LRR-RLK MOL1 is necessary for cambium homeostasis in Arabidopsis thaliana. By employing promoter reporter lines, we reveal that MOL1 is active in a domain that is distinct from the domain of the positively acting CLE41/PXY signaling module. In particular, we show that MOL1 acts in an opposing manner to the CLE41/PXY module and that changing the domain or level of MOL1 expression both result in disturbed cambium organization. Underlining discrete roles of MOL1 and PXY, both LRR-RLKs are not able to replace each other when their expression domains are interchanged. Furthermore, MOL1 but not PXY is able to rescue CLV1 deficiency in the shoot apical meristem. By identifying genes mis-expressed in mol1 mutants, we demonstrate that MOL1 represses genes associated with stress-related ethylene and jasmonic acid hormone signaling pathways which have known roles in coordinating lateral growth of the Arabidopsis stem. Our findings provide evidence that common regulatory mechanisms in different plant stem cell niches are adapted to specific niche anatomies and emphasize the importance of a complex spatial organization of intercellular signaling cascades for a strictly bidirectional tissue production. PMID:26991973

  17. Wrinkled1, a ubiquitous regulator in oil accumulating tissues from Arabidopsis embryos to oil palm mesocarp.

    Directory of Open Access Journals (Sweden)

    Wei Ma

    Full Text Available Wrinkled1 (AtWRI1 is a key transcription factor in the regulation of plant oil synthesis in seed and non-seed tissues. The structural features of WRI1 important for its function are not well understood. Comparison of WRI1 orthologs across many diverse plant species revealed a conserved 9 bp exon encoding the amino acids "VYL". Site-directed mutagenesis of amino acids within the 'VYL' exon of AtWRI1 failed to restore the full oil content of wri1-1 seeds, providing direct evidence for an essential role of this small exon in AtWRI1 function. Arabidopsis WRI1 is predicted to have three alternative splice forms. To understand expression of these splice forms we performed RNASeq of Arabidopsis developing seeds and queried other EST and RNASeq databases from several tissues and plant species. In all cases, only one splice form was detected and VYL was observed in transcripts of all WRI1 orthologs investigated. We also characterized a phylogenetically distant WRI1 ortholog (EgWRI1 as an example of a non-seed isoform that is highly expressed in the mesocarp tissue of oil palm. The C-terminal region of EgWRI1 is over 90 amino acids shorter than AtWRI1 and has surprisingly low sequence conservation. Nevertheless, the EgWRI1 protein can restore multiple phenotypes of the Arabidopsis wri1-1 loss-of-function mutant, including reduced seed oil, the "wrinkled" seed coat, reduced seed germination, and impaired seedling establishment. Taken together, this study provides an example of combining phylogenetic analysis with mutagenesis, deep-sequencing technology and computational analysis to examine key elements of the structure and function of the WRI1 plant transcription factor.

  18. Wrinkled1, a ubiquitous regulator in oil accumulating tissues from Arabidopsis embryos to oil palm mesocarp.

    Science.gov (United States)

    Ma, Wei; Kong, Que; Arondel, Vincent; Kilaru, Aruna; Bates, Philip D; Thrower, Nicholas A; Benning, Christoph; Ohlrogge, John B

    2013-01-01

    Wrinkled1 (AtWRI1) is a key transcription factor in the regulation of plant oil synthesis in seed and non-seed tissues. The structural features of WRI1 important for its function are not well understood. Comparison of WRI1 orthologs across many diverse plant species revealed a conserved 9 bp exon encoding the amino acids "VYL". Site-directed mutagenesis of amino acids within the 'VYL' exon of AtWRI1 failed to restore the full oil content of wri1-1 seeds, providing direct evidence for an essential role of this small exon in AtWRI1 function. Arabidopsis WRI1 is predicted to have three alternative splice forms. To understand expression of these splice forms we performed RNASeq of Arabidopsis developing seeds and queried other EST and RNASeq databases from several tissues and plant species. In all cases, only one splice form was detected and VYL was observed in transcripts of all WRI1 orthologs investigated. We also characterized a phylogenetically distant WRI1 ortholog (EgWRI1) as an example of a non-seed isoform that is highly expressed in the mesocarp tissue of oil palm. The C-terminal region of EgWRI1 is over 90 amino acids shorter than AtWRI1 and has surprisingly low sequence conservation. Nevertheless, the EgWRI1 protein can restore multiple phenotypes of the Arabidopsis wri1-1 loss-of-function mutant, including reduced seed oil, the "wrinkled" seed coat, reduced seed germination, and impaired seedling establishment. Taken together, this study provides an example of combining phylogenetic analysis with mutagenesis, deep-sequencing technology and computational analysis to examine key elements of the structure and function of the WRI1 plant transcription factor. PMID:23922666

  19. Temporal and Spatial Requirement of EMF1 Activity for Arabidopsis Vegetative and Reproductive Development

    Institute of Scientific and Technical Information of China (English)

    Rosario Sánchez; Minjung Y.Kim; Myriam Calonje; Yong-Hwan Moon; Z.Renee Sung

    2009-01-01

    EMBRYONIC FLOWER (EMF) genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis.Removal of EMF gene function caused plants to flower upon germination,producing abnormal and sterile flowers.The pleiotropic effect of emf1 mutation suggests its requirement for gene programs involved in diverse developmental processes.Transgenic plants harboring EMF1 promoter::glucuronidase (GUS) reporter gene were generated to investigate the temporal and spatial expression pattern of EMF1.These plants displayed differential GUS activity in vegetative and flower tissues,consistent with the role of EMF1 in regulating multiple gene programs.EMF1::GUS expression pattern in emf mutants suggests organ-specific auto-regulation.Sense- and antisense (as) EMF1 cDNA were expressed under the control of stage- and tissue-specific promoters in transgenic plants.Characterization of these transgenic plants showed that EMF1 activity is required in meristematic as well as differentiating tissues to rescue emf mutant phenotype.Temporal removal or reduction of EMF1 activity in the embryo or shoot apex of wild-type seedlings was sufficient to cause early flowering and terminal flower formation in adult plants.Such reproductive cell memory is reflected in the flower MADS-box gene activity expressed prior to flowering in these early flowering plants.However,temporal removal of EMF1 activity in flower meristem did not affect flower development.Our results are consistent with EMF1's primary role in repressing flowering in order to allow for vegetative growth.

  20. Stress-related function of bHLH109 in somatic embryo induction in Arabidopsis.

    Science.gov (United States)

    Nowak, Katarzyna; Gaj, Małgorzata D

    2016-04-01

    The bHLH109 gene of the bHLH family was identified among the transcription factor encoding genes that were differentially expressed in an embryogenic culture of Arabidopsis. A strong activation of bHLH109 expression was found to be associated with somatic embryogenesis (SE) induction. Several pieces of evidence suggested the involvement of bHLH109 in SE, including the high stimulation of the gene expression in SE-induced explants, which contrasts to the drastically lower level of the gene transcripts in the non-embryogenic callus and in tissue that is induced towards shoot regeneration via organogenesis. Moreover, in contrast to the overexpression of bHLH109, which has been indicated to enhance SE induction in a culture, the bhlh109 knock-out mutation was found to impair the embryogenic potential of explants. In order to identify the genes interacting with the bHLH109, the candidate co-expressed genes were identified in a yeast one hybrid assay. The in vitro regulatory interactions that were identified were verified through mutant and expression analysis. The results suggest that in SE bHLH109 acts as an activator of ECP63, a member of the LEA (LATE EMBRYOGENESIS ABUNDANT) family. Among the potential regulators of bHLH109, three candidates (At5g61620, bZIP4 and bZIP43) were indicated to possibly control bHLH109. The functions of all of the genes that are assumed to interact with bHLH109 are annotated to stress responses. Collectively, the results of the study provide new evidence that cell responses to stress that is imposed under in vitro conditions underlies the promotion of SE. bHLH109 may play a central role in the stress-related mechanism of SE induction via an increased accumulation of the LEA protein (ECP63), which results in the enhanced tolerance of the cells to stress. PMID:26973252

  1. Localization of Iron in Arabidopsis Seed Requires the Vacuolar Membrane Transporter VIT1

    International Nuclear Information System (INIS)

    Iron deficiency is a major human nutritional problem wherever plant-based diets are common. Using synchrotron x-ray fluorescence microtomography to directly visualize iron in Arabidopsis seeds, we show that iron is localized primarily to the provascular strands of the embryo. This localization is completely abolished when the vacuolar iron uptake transporter VIT1 is disrupted. Vacuolar iron storage is also critical for seedling development because vit1-1 seedlings grow poorly when iron is limiting. We have uncovered a fundamental aspect of seed biology that will ultimately aid the development of nutrient-rich seed, benefiting both human health and agricultural productivity

  2. Maternal Mga is required for Wnt signaling and organizer formation in the early Xenopus embryo

    Institute of Scientific and Technical Information of China (English)

    Fei Gu; Huijuan Shi; Li Gao; Haiyan Zhang; Qinghua Tao

    2012-01-01

    Maternal Wnt11 is both necessary and sufficient for the formation of Spemann organizer in Xenopus embryo.Xnr3 and Siamois have been identified as the direct target genes of maternal Wnt11/β-catenin during organizer induction.The depletion of maternal XTcf3 resulted in the ectopic expression of Xnr3 and Siamois,suggesting the activity of β-catenin/XTcf3 is strictly regulated in the early Xenopus embryos.Here,we show that Xenopus mga (Xmga) is a maternal gene required for dorsal axis formation.Overexpression experiments indicate that mouse Mga potentiates the activity of β-catenin in the induction of organizer-specific genes.Depletion of maternal Xmga results in the dramatic decrease of the expression of organizer genes and ventralization phenotype,indicating that Xmga is required for β-catenin function and organizer formation.Depletion of XTcf3 cannot rescue organizer gene expression and axis formation in Xmga-depleted embryos,suggesting Xmga is downstream of XTcf3 during organizer induction.We conclude that maternal Xmga is critical for the function of β-catenin during organizer formation and dorsal development of Xenopus embryo.To our knowledge,this is a report for the first time to implicate Mga in regulating Wnt signaling.

  3. Maternal Mga is required for Wnt signaling and organizer formation in the early Xenopus embryo.

    Science.gov (United States)

    Gu, Fei; Shi, Huijuan; Gao, Li; Zhang, Haiyan; Tao, Qinghua

    2012-11-01

    Maternal Wnt11 is both necessary and sufficient for the formation of Spemann organizer in Xenopus embryo. Xnr3 and Siamois have been identified as the direct target genes of maternal Wnt11/β-catenin during organizer induction. The depletion of maternal XTcf3 resulted in the ectopic expression of Xnr3 and Siamois, suggesting the activity of β-catenin/XTcf3 is strictly regulated in the early Xenopus embryos. Here, we show that Xenopus mga (Xmga) is a maternal gene required for dorsal axis formation. Overexpression experiments indicate that mouse Mga potentiates the activity of β-catenin in the induction of organizer-specific genes. Depletion of maternal Xmga results in the dramatic decrease of the expression of organizer genes and ventralization phenotype, indicating that Xmga is required for β-catenin function and organizer formation. Depletion of XTcf3 cannot rescue organizer gene expression and axis formation in Xmga-depleted embryos, suggesting Xmga is downstream of XTcf3 during organizer induction. We conclude that maternal Xmga is critical for the function of β-catenin during organizer formation and dorsal development of Xenopus embryo. To our knowledge, this is a report for the first time to implicate Mga in regulating Wnt signaling. PMID:23070227

  4. BODYGUARD is required for the biosynthesis of cutin in Arabidopsis.

    Science.gov (United States)

    Jakobson, Liina; Lindgren, Leif Ove; Verdier, Gaëtan; Laanemets, Kristiina; Brosché, Mikael; Beisson, Fred; Kollist, Hannes

    2016-07-01

    The cuticle plays a critical role in plant survival during extreme drought conditions. There are, however, surprisingly, many gaps in our understanding of cuticle biosynthesis. An Arabidopsis thaliana T-DNA mutant library was screened for mutants with enhanced transpiration using a simple condensation spot method. Five mutants, named cool breath (cb), were isolated. The cb5 mutant was found to be allelic to bodyguard (bdg), which is affected in an α/β-hydrolase fold protein important for cuticle structure. The analysis of cuticle components in cb5 (renamed as bdg-6) and another T-DNA mutant allele (bdg-7) revealed no impairment in wax synthesis, but a strong decrease in total cutin monomer load in young leaves and flowers. Root suberin content was also reduced. Overexpression of BDG increased total leaf cutin monomer content nearly four times by affecting preferentially C18 polyunsaturated ω-OH fatty acids and dicarboxylic acids. Whole-plant gas exchange analysis showed that bdg-6 had higher cuticular conductance and rate of transpiration; however, plant lines overexpressing BDG resembled the wild-type with regard to these characteristics. This study identifies BDG as an important component of the cutin biosynthesis machinery in Arabidopsis. We also show that, using BDG, cutin can be greatly modified without altering the cuticular water barrier properties and transpiration. PMID:26990896

  5. The ASH1 HOMOLOG 2 (ASHH2 histone H3 methyltransferase is required for ovule and anther development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Paul E Grini

    Full Text Available BACKGROUND: SET-domain proteins are histone lysine (K methyltransferases (HMTase implicated in defining transcriptionally permissive or repressive chromatin. The Arabidopsis ASH1 HOMOLOG 2 (ASHH2 protein (also called SDG8, EFS and CCR1 has been suggested to methylate H3K4 and/or H3K36 and is similar to Drosophila ASH1, a positive maintainer of gene expression, and yeast Set2, a H3K36 HMTase. Mutation of the ASHH2 gene has pleiotropic developmental effects. Here we focus on the role of ASHH2 in plant reproduction. METHODOLOGY/PRINCIPAL FINDINGS: A slightly reduced transmission of the ashh2 allele in reciprocal crosses implied involvement in gametogenesis or gamete function. However, the main requirement of ASHH2 is sporophytic. On the female side, close to 80% of mature ovules lack embryo sac. On the male side, anthers frequently develop without pollen sacs or with specific defects in the tapetum layer, resulting in reduction in the number of functional pollen per anther by up to approximately 90%. In consistence with the phenotypic findings, an ASHH2 promoter-reporter gene was expressed at the site of megaspore mother cell formation as well as tapetum layers and pollen. ashh2 mutations also result in homeotic changes in floral organ identity. Transcriptional profiling identified more than 300 up-regulated and 600 down-regulated genes in ashh2 mutant inflorescences, whereof the latter included genes involved in determination of floral organ identity, embryo sac and anther/pollen development. This was confirmed by real-time PCR. In the chromatin of such genes (AP1, AtDMC1 and MYB99 we observed a reduction of H3K36 trimethylation (me3, but not H3K4me3 or H3K36me2. CONCLUSIONS/SIGNIFICANCE: The severe distortion of reproductive organ development in ashh2 mutants, argues that ASHH2 is required for the correct expression of genes essential to reproductive development. The reduction in the ashh2 mutant of H3K36me3 on down-regulated genes relevant to

  6. Nucleolar development and allocation of key nucleolar proteins require de novo transcription in bovine embryos

    DEFF Research Database (Denmark)

    Svarcova, Olga; Laurincik, Jozef; Avery, Birthe;

    2007-01-01

    The goal of the present study was to investigate whether key nucleolar proteins involved in ribosomal RNA (rRNA) transcription and processing are transcribed de novo or from maternally inherited messenger RNAs (mRNA) in bovine embryos, and to which extent de novo transcription of these proteins m......RNA is required for the development of functional nucleoli during the major activation of the embryonic genome. Immunofluorescence for localization of key nucleolar proteins, autoradiography for detection of transcriptional activity, and transmission electron microscopy were applied to in vitro produc ed...... bovine embryos cultured from the 2-cell stage with or without (control groups) a-amanitin, which blocks the RNA plymerases II and III transcription and, thus the synthesis of mRNA. In the control groups, weak autoradiographic labelling was initially observed in the periphery of few nuclei at the 4-cell...

  7. ASK1 physically interacts with COI1 and is required for male fertility in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    戴良英; 徐领会; 黄大昉; 李栒; 罗宽; 官春云

    2002-01-01

    Jasmonates are a new class of plant hormones that play important roles in plant development and plant defense. The COI1 gene was previously shown to be required for jasmonate- regulated plant fertility and defense. We demonstrated for the first time that COI1 interacts with the Arabidopsis SKP1-LIKE1 (ASK1) to form a complex that is required for jasmonate action in planta. Functional analysis by antisense strategy showed that ASK1 is involved in male fertility.

  8. Hormonally regulated overexpression of Arabidopsis WUS and conifer LEC1 (CHAP3A) in transgenic white spruce: implications for somatic embryo development and somatic seedling growth.

    Science.gov (United States)

    Klimaszewska, Krystyna; Pelletier, Gervais; Overton, Catherine; Stewart, Don; Rutledge, Robert G

    2010-07-01

    Adult conifers are still recalcitrant in clonal propagation despite significant advances in forest tree biotechnology. Plant regeneration through somatic embryogenesis from explants older than mature zygotic embryos is either difficult or impossible to achieve. To investigate if ectopic expression of transcription factors involved in the induction of the embryogenic process would induce somatic embryogenesis in Picea glauca (white spruce) somatic plants, we used the LEAFY-COTYLEDON1 homolog cloned from Picea mariana, CHAP3A, and Arabidopsis thaliana WUS to transform embryonal mass of P. glauca. Ectopic gene expression was induced by 17-beta-estradiol during stages of somatic embryogenesis (early embryogenesis and late embryogenesis) and somatic seedling growth in the transgenics. Of the two transcription factors, only WUS produced severe phenotypes by disrupting the development of somatic embryos on the maturation medium and inhibiting germination. However, none of the transgenes induced ectopic somatic embryogenesis even in the presence of plant growth regulators. Absolute quantitative PCR confirmed the expression of both CHAP3A and WUS in transgenic embryonal mass and in all parts of somatic seedlings. A high expression of the transgenes did not influence expression profiles of any of the ten other transcription factors tested, some of which have been known to be involved in the process of embryogenesis. Implications of these results for further work are discussed. PMID:20424847

  9. The glutaredoxin ATGRXS13 is required to facilitate Botrytis cinerea infection of Arabidopsis thaliana plants

    OpenAIRE

    Camera, Sylvain La; L’Haridon, Floriane; Astier, Jérémy; Zander, Mark; Abou-Mansour, Eliane; Page, Gonzague; Thurow, Corinna; Wendehenne, David; Gatz, Christiane; Métraux, Jean-Pierre; Lamotte, Olivier

    2011-01-01

    Botrytis cinerea is a major pre- and post-harvest necrotrophic pathogen with a broad host range that causes substantial crop losses. The plant hormone jasmonic acid (JA) is involved in the basal resistance against this fungus. Despite basal resistance, virulent strains of B. cinerea can cause disease on Arabidopsis thaliana and virulent pathogens can interfere with the metabolism of the host in a way to facilitate infection of the plant. However, plant genes that are required by the pathogen ...

  10. Seed germination of GA-insensitive sleepy1 mutants does not require RGL2 protein disappearance in Arabidopsis

    Science.gov (United States)

    Seed germination is a complex developmental process regulated by phytohormones. The phytohormone abscisic acid (ABA) inhibits seed germination, whereas gibberellin (GA) stimulates seed germination. In tomato and Arabidopsis, GA is clearly required for seed germination. Recent evidence suggests tha...

  11. CESA5 Is Required for the Synthesis of Cellulose with a Role in Structuring the Adherent Mucilage of Arabidopsis Seeds

    OpenAIRE

    Sullivan, Stuart; Ralet, Marie-Christine; Berger, Adeline; Diatloff, Eugene; Bischoff, Volker; Gonneau, Martine; Marion-Poll, Annie

    2011-01-01

    Imbibed Arabidopsis (Arabidopsis thaliana) seeds are encapsulated by mucilage that is formed of hydrated polysaccharides released from seed coat epidermal cells. The mucilage is structured with water-soluble and adherent layers, with cellulose present uniquely in an inner domain of the latter. Using a reverse-genetic approach to identify the cellulose synthases (CESAs) that produce mucilage cellulose, cesa5 mutants were shown to be required for the correct formation of these layers. Expressio...

  12. The gametophytic expression of the gene for sensor histidine kinase CKI1 is essential for embryo sac formation in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Hejátko, Jan; Pernisová, M.; Eneva, T.; Palme, K.; Brzobohatý, Břetislav

    Brno : Masarykova univerzita v Brně, 2003 - (Dubová, J.). s. 67 ISBN 80-210-3194-8. [International Conference on Plant Embryology /9./. 01.09.2003-03.09.2003, Brno] R&D Projects: GA MŠk VS96096; GA MŠk LN00A081 Grant ostatní: QLRT(XE) 2000-0020; QLRT-CT(XE) 2001-01871 Institutional research plan: CEZ:AV0Z5004920 Keywords : embryo sac formation * CKI1 * histidine kinase Subject RIV: BO - Biophysics

  13. A novel chloroplast-localized protein EMB1303 is required for chloroplast development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiaozhen Huang; Xiaoyan Zhang; Shuhua Yang

    2009-01-01

    To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly im-paired. The plastids of emb1303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Mieroarray and RT-PCR analyses revealed that a number of nuclear-and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accu-mulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMBI303 is essential for chloroplast development.

  14. Neural crest induction by paraxial mesoderm in Xenopus embryos requires FGF signals.

    Science.gov (United States)

    Monsoro-Burq, Anne-Hélène; Fletcher, Russell B; Harland, Richard M

    2003-07-01

    At the border of the neural plate, the induction of the neural crest can be achieved by interactions with the epidermis, or with the underlying mesoderm. Wnt signals are required for the inducing activity of the epidermis in chick and amphibian embryos. Here, we analyze the molecular mechanisms of neural crest induction by the mesoderm in Xenopus embryos. Using a recombination assay, we show that prospective paraxial mesoderm induces a panel of neural crest markers (Slug, FoxD3, Zic5 and Sox9), whereas the future axial mesoderm only induces a subset of these genes. This induction is blocked by a dominant negative (dn) form of FGFR1. However, neither dnFGFR4a nor inhibition of Wnt signaling prevents neural crest induction in this system. Among the FGFs, FGF8 is strongly expressed by the paraxial mesoderm. FGF8 is sufficient to induce the neural crest markers FoxD3, Sox9 and Zic5 transiently in the animal cap assay. In vivo, FGF8 injections also expand the Slug expression domain. This suggests that FGF8 can initiate neural crest formation and cooperates with other DLMZ-derived factors to maintain and complete neural crest induction. In contrast to Wnts, eFGF or bFGF, FGF8 elicits neural crest induction in the absence of mesoderm induction and without a requirement for BMP antagonists. In vivo, it is difficult to dissociate the roles of FGF and WNT factors in mesoderm induction and neural patterning. We show that, in most cases, effects on neural crest formation were parallel to altered mesoderm or neural development. However, neural and neural crest patterning can be dissociated experimentally using different dominant-negative manipulations: while Nfz8 blocks both posterior neural plate formation and neural crest formation, dnFGFR4a blocks neural patterning without blocking neural crest formation. These results suggest that different signal transduction mechanisms may be used in neural crest induction, and anteroposterior neural patterning. PMID:12783784

  15. Utilisation des mutations induites pour l'étude de l'embryogenèse chez le haricot Phaseolus vulgaris L. et deux plantes modèles Arabidopsis thaliana (L. Heynh. et Zea mays L.

    Directory of Open Access Journals (Sweden)

    Silué, S.

    2011-01-01

    Full Text Available Use of induced mutations in embryogenesis study in bean Phaseolus vulgaris L. and two model plants, Arabidopsis thaliana (L. Heynh. and Zea mays L.. Breeding of common bean, Phaseolus vulgaris L., through interspecific hybridizations with the species Phaseolus coccineus L. and Phaseolus polyanthus Greenm. as female parents leads to the abortion of immature embryos. Identification of genes required for embryo development could partly explain the abortion of hybrid embryos; induced mutations could thus be an alternative to identify key genes involved in Phaseolus embryogenesis. This paper is a review which shows a few examples of the use of induced mutations in the identification of essential genes for embryogenesis in two model plants, Arabidopsis thaliana (L. Heyhn. for dicots and Zea mays L. for monocots. In these two species, embryo development mutants have been isolated using insertional mutagenesis and chemical mutagenesis with Ethyl Methane Sulfonate (EMS. Arabidopsis embryo mutants are affected in apical-basal axis polarity, radial pattern and in post-embryonic stages. Some Arabidopsis embryo mutants are defected in auxin signalisation. In maize, defective kernel (dek mutants are affected in the embryo and the endosperm, while in embryo specific (emb mutants, only the embryo is affected. In common bean, plants deficient in seed development were isolated using EMS mutagenesis. Embryos inside the seeds fail to growth at different stages of development and show abnormalities mainly in the suspensor and the cotyledons.

  16. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu

    2014-11-21

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  17. Promoter analysis in living zebrafish embryos identifies a cis-acting motif required for neuronal expression of GATA-2

    OpenAIRE

    Meng, Anming; Tang, Hong; Ong, Bruce A.; Farrell, Michael J.; Lin, Shuo

    1997-01-01

    We have used zebrafish embryos to dissect the promoter activity of a gene with a complex expression pattern during embryogenesis. GATA-2 is a transcription factor required for hematopoiesis and is dynamically expressed in hematopoietic tissues and in the central nervous system. Using constructs containing zebrafish GATA-2 genomic flanking sequences and the green fluorescent protein (GFP) reporter gene, we demonstrate that distinct regulatory domains are required for hematopoietic, enveloping ...

  18. Left-right patterning in Xenopus conjoined twin embryos requires serotonin signaling and gap junctions.

    Science.gov (United States)

    Vandenberg, Laura N; Blackiston, Douglas J; Rea, Adam C; Dore, Timothy M; Levin, Michael

    2014-01-01

    A number of processes operating during the first cell cleavages enable the left-right (LR) axis to be consistently oriented during Xenopus laevis development. Prior work showed that secondary organizers induced in frog embryos after cleavage stages (i.e. conjoined twins arising from ectopic induced primary axes) correctly pattern their own LR axis only when a primary (early) organizer is also present. This instructive effect confirms the unique LR patterning functions that occur during early embryogenesis, but leaves open the question: which mechanisms that operate during early stages are also involved in the orientation of later-induced organizers? We sought to distinguish the two phases of LR patterning in secondary organizers (LR patterning of the primary twin and the later transfer of this information to the secondary twin) by perturbing only the latter process. Here, we used reagents that do not affect primary LR patterning at the time secondary organizers form to inhibit each of 4 mechanisms in the induced twin. Using pharmacological, molecular-genetic, and photo-chemical tools, we show that serotonergic and gap-junctional signaling, but not proton or potassium flows, are required for the secondary organizer to appropriately pattern its LR axis in a multicellular context. We also show that consistently-asymmetric gene expression begins prior to ciliary flow. Together, our data highlight the importance of physiological signaling in the propagation of cleavage-derived LR orientation to multicellular cell fields. PMID:25896280

  19. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development.

    Science.gov (United States)

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; Stonebloom, Solomon; Smith-Moritz, Andreia M; Pauly, Markus; Orellana, Ariel; Scheller, Henrik Vibe; Heazlewood, Joshua L

    2016-01-01

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development. PMID:27381418

  20. DRB2 is required for microRNA biogenesis in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Andrew L Eamens

    Full Text Available BACKGROUND: The Arabidopsis thaliana (Arabidopsis DOUBLE-STRANDED RNA BINDING (DRB protein family consists of five members, DRB1 to DRB5. The biogenesis of two developmentally important small RNA (sRNA species, the microRNAs (miRNAs and trans-acting small interfering RNAs (tasiRNAs by DICER-LIKE (DCL endonucleases requires the assistance of DRB1 and DRB4 respectively. The importance of miRNA-directed target gene expression in plant development is exemplified by the phenotypic consequence of loss of DRB1 activity (drb1 plants. PRINCIPAL FINDINGS: Here we report that the developmental phenotype of the drb235 triple mutant plant is the result of deregulated miRNA biogenesis in the shoot apical meristem (SAM region. The expression of DRB2, DRB3 and DRB5 in wild-type seedlings is restricted to the SAM region. Small RNA sequencing of the corresponding tissue of drb235 plants revealed altered miRNA accumulation. Approximately half of the miRNAs detected remained at levels equivalent to those of wild-type plants. However, the accumulation of the remaining miRNAs was either elevated or reduced in the triple mutant. Examination of different single and multiple drb mutants revealed a clear association between the loss of DRB2 activity and altered accumulation for both the elevated and reduced miRNA classes. Furthermore, we show that the constitutive over-expression of DRB2 outside of its wild-type expression domain can compensate for the loss of DRB1 activity in drb1 plants. CONCLUSIONS/SIGNIFICANCE: Our results suggest that in the SAM region, DRB2 is both antagonistic and synergistic to the role of DRB1 in miRNA biogenesis, adding an additional layer of gene regulatory complexity in this developmentally important tissue.

  1. An Endosperm-Associated Cuticle Is Required for Arabidopsis Seed Viability, Dormancy and Early Control of Germination.

    Directory of Open Access Journals (Sweden)

    Julien De Giorgi

    2015-12-01

    Full Text Available Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA and abscisic acid (ABA signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeability to outer compounds. However, the role of cutin in mature seed physiology and germination remains poorly understood. Here we identify in mature seeds a thick cuticular film covering the entire outer surface of the endosperm. This seed cuticle is defective in cutin-deficient bodyguard1 seeds, which is associated with alterations in endospermic permeability. Furthermore, mutants affected in cutin biosynthesis display low seed dormancy and viability levels, which correlates with higher levels of seed lipid oxidative stress. Upon seed imbibition cutin biosynthesis genes are essential to prevent endosperm cellular expansion and testa rupture in response to low GA synthesis. Taken together, our findings suggest that in the course of land plant evolution cuticular structures were co-opted to achieve key physiological seed properties.

  2. A "Whirly" transcription factor is required for salicylic acid-dependent disease resistance in Arabidopsis.

    Science.gov (United States)

    Desveaux, Darrell; Subramaniam, Rajagopal; Després, Charles; Mess, Jean-Nicholas; Lévesque, Caroline; Fobert, Pierre R; Dangl, Jeffery L; Brisson, Normand

    2004-02-01

    Transcriptional reprogramming is critical for plant disease resistance responses; its global control is not well understood. Salicylic acid (SA) can induce plant defense gene expression and a long-lasting disease resistance state called systemic acquired resistance (SAR). Plant-specific "Whirly" DNA binding proteins were previously implicated in defense gene regulation. We demonstrate that the potato StWhy1 protein is a transcriptional activator of genes containing the PBF2 binding PB promoter element. DNA binding activity of AtWhy1, the Arabidopsis StWhy1 ortholog, is induced by SA and is required for both SA-dependent disease resistance and SA-induced expression of an SAR response gene. AtWhy1 is required for both full basal and specific disease resistance responses. The transcription factor-associated protein NPR1 is also required for SAR. Surprisingly, AtWhy1 activation by SA is NPR1 independent, suggesting that AtWhy1 works in conjunction with NPR1 to transduce the SA signal. Our analysis of AtWhy1 adds a critical component to the SA-dependent plant disease resistance response. PMID:14960277

  3. β-catenin-mediated adhesion is required for successful preimplantation mouse embryo development.

    Science.gov (United States)

    Messerschmidt, Daniel; de Vries, Wilhelmine N; Lorthongpanich, Chanchao; Balu, Sathish; Solter, Davor; Knowles, Barbara B

    2016-06-01

    β-catenin (CTNNB1) is integral to cell adhesion and to the canonical Wnt signaling pathway. The effects of maternal and zygotic CTNNB1 on embryogenesis have each been separately assessed, whereas the effect of its total absence has not. As the 'traditional' conditional Ctnnb1 knockout alleles give rise to truncated CTNNB1 fragments, we designed a new knockout allele incapable of CTNNB1 production. Mouse embryos lacking intact maternal/zygotic CTNNB1 from two knockout strains were examined in detail. Preimplantation embryos are formed, yet abnormalities in their size and shape were found throughout pre- and early postimplantation development. In the absence of the zona pellucida, embryos lacking CTNNB1 undergo fission and these separated blastomeres can become small trophoblastic vesicles, which in turn induce decidual reactions. Comparing the severity of this defective adhesion phenotype in embryos bearing the null allele with those carrying the 'traditional' knockout allele suggests a hypomorphic effect of the truncated CTNNB1 protein fragment, an important observation with possible impact on previous and future studies. PMID:27246714

  4. POPCORN Functions in the Auxin Pathway to Regulate Embryonic Body Plan and Meristem Organization in Arabidopsis

    NARCIS (Netherlands)

    Xiang, D.Q.; Yang, H.; Venglat, P.; Cao, Y.G.; Wen, R.; Ren, M.Z.; Stone, S.; Wang, E.; Wang, H.; Xiao, W.; Weijers, D.; Berleth, T.; Laux, T.; Selvaraj, G.; Datla, R.

    2011-01-01

    The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN (PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN

  5. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua

    2010-04-16

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

  6. TNL-mediated immunity in Arabidopsis requires complex regulation of the redundant ADR1 gene family.

    Science.gov (United States)

    Dong, Oliver Xiaoou; Tong, Meixuezi; Bonardi, Vera; El Kasmi, Farid; Woloshen, Virginia; Wünsch, Lisa K; Dangl, Jeffery L; Li, Xin

    2016-05-01

    Nucleotide-binding leucine-rich repeat proteins (NLRs) serve as intracellular immune receptors in animals and plants. Sensor NLRs perceive pathogen-derived effector molecules and trigger robust host defense. Recent studies revealed the role of three coiled-coil-type NLRs (CNLs) of the ADR1 family - ADR1, ADR1-L1 and ADR1-L2 - as redundant helper NLRs, whose function is required for defense mediated by multiple sensor NLRs. From a mutant snc1-enhancing (MUSE) forward genetic screen in Arabidopsis targeted to identify negative regulators of snc1 that encodes a TIR-type NLR (TNL), we isolated two alleles of muse15, both carrying mutations in ADR1-L1. Interestingly, loss of ADR1-L1 also enhances immunity-related phenotypes in other autoimmune mutants including cpr1, bal and lsd1. This immunity-enhancing effect is not mediated by increased SNC1 protein stability, nor is it fully dependent on the accumulation of the defense hormone salicylic acid (SA). Transcriptional analysis revealed an upregulation of ADR1 and ADR1-L2 in the adr1-L1 background, which may overcompensate the loss of ADR1-L1, resulting in enhanced immunity. Interestingly, autoimmunity of snc1 and chs2, which encode typical TNLs, is fully suppressed by the adr1 triple mutant, suggesting that the ADRs are required for TNL downstream signaling. This study extends our knowledge on the interplay among ADRs and reveals their complexity in defense regulation. PMID:27074399

  7. A Protein Complex Required for Polymerase V Transcripts and RNA- Directed DNA Methylation in Arabidopsis

    KAUST Repository

    Law, Julie A.

    2010-05-01

    DNA methylation is an epigenetic modification associated with gene silencing. In Arabidopsis, DNA methylation is established by DOMAINS REARRANGED METHYLTRANSFERASE 2 (DRM2), which is targeted by small interfering RNAs through a pathway termed RNA-directed DNA methylation (RdDM) [1, 2]. Recently, RdDM was shown to require intergenic noncoding (IGN) transcripts that are dependent on the Pol V polymerase. These transcripts are proposed to function as scaffolds for the recruitment of downstream RdDM proteins, including DRM2, to loci that produce both siRNAs and IGN transcripts [3]. However, the mechanism(s) through which Pol V is targeted to specific genomic loci remains largely unknown. Through affinity purification of two known RdDM components, DEFECTIVE IN RNA-DIRECTED DNA METHYLATION 1 (DRD1) [4] and DEFECTIVE IN MERISTEM SILENCING 3 (DMS3) [5, 6], we found that they copurify with each other and with a novel protein, RNA-DIRECTED DNA METHYLATION 1 (RDM1), forming a complex we term DDR. We also found that DRD1 copurified with Pol V subunits and that RDM1, like DRD1 [3] and DMS3 [7], is required for the production of Pol V-dependent transcripts. These results suggest that the DDR complex acts in RdDM at a step upstream of the recruitment or activation of Pol V. © 2010 Elsevier Ltd. All rights reserved.

  8. Arabidopsis thaliana glyoxalase 2-1 is required during abiotic stress but is not essential under normal plant growth.

    Directory of Open Access Journals (Sweden)

    Sriram Devanathan

    Full Text Available The glyoxalase pathway, which consists of the two enzymes, GLYOXALASE 1 (GLX 1 (E.C.: 4.4.1.5 and 2 (E.C.3.1.2.6, has a vital role in chemical detoxification. In Arabidopsis thaliana there are at least four different isoforms of glyoxalase 2, two of which, GLX2-1 and GLX2-4 have not been characterized in detail. Here, the functional role of Arabidopsis thaliana GLX2-1 is investigated. Glx2-1 loss-of-function mutants and plants that constitutively over-express GLX2-1 resemble wild-type plants under normal growth conditions. Insilico analysis of publicly available microarray datasets with ATTEDII, Mapman and Genevestigator indicate potential role(s in stress response and acclimation. Results presented here demonstrate that GLX2-1 gene expression is up-regulated in wild type Arabidopsis thaliana by salt and anoxia stress, and by excess L-Threonine. Additionally, a mutation in GLX2-1 inhibits growth and survival during abiotic stresses. Metabolic profiling studies show alterations in the levels of sugars and amino acids during threonine stress in the plants. Elevated levels of polyamines, which are known stress markers, are also observed. Overall our results suggest that Arabidopsis thaliana GLX2-1 is not essential during normal plant life, but is required during specific stress conditions.

  9. UFO in the Arabidopsis inflorescence apex is required for floral-meristem identity and bract suppression.

    Science.gov (United States)

    Hepworth, Shelley R; Klenz, Jennifer E; Haughn, George W

    2006-03-01

    The UNUSUAL FLORAL ORGANS (UFO) gene of Arabidopsis encodes an F-box protein required for the determination of floral-organ and floral-meristem identity. Mutation of UFO leads to dramatic changes in floral-organ type which are well-characterized whereas inflorescence defects are more subtle and less understood. These defects include an increase in the number of secondary inflorescences, nodes that alternate between forming flowers and secondary inflorescences, and nodes in which a single flower is subtended by a bract. Here, we show how inflorescence defects correlate with the abnormal development of floral primordia and establish a temporal requirement for UFO in this process. At the inflorescence apex of ufo mutants, newly formed primordia are initially bract-like. Expression of the floral-meristem identity genes LFY and AP1 are confined to a relatively small adaxial region of these primordia with expression of the bract-identity marker FIL observed in cells that comprise the balance of the primordia. Proliferation of cells in the adaxial region of these early primordia is delayed by several nodes such that primordia appear "chimeric" at several nodes, having visible floral and bract components. However, by late stage 2 of floral development, growth of the bract generally ceases and is overtaken by development of the floral primordium. This abnormal pattern of floral meristem development is not rescued by expression of UFO from the AP1 promoter, indicating that UFO is required prior to AP1 activation for normal development of floral primordia. We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract. PMID:16244866

  10. Vitamin D receptor signaling is required for heart development in zebrafish embryo.

    Science.gov (United States)

    Kwon, Hye-Joo

    2016-02-12

    Vitamin D has been found to be associated with cardiovascular diseases. However, the role of vitamin D in heart development during embryonic period is largely unknown. Vitamin D induces its genomic effects through its nuclear receptor, the vitamin D receptor (VDR). The present study investigated the role of VDR on heart development by antisense-mediated knockdown approaches in zebrafish model system. In zebrafish embryos, two distinct VDR genes (vdra and vdrb) have been identified. Knockdown of vdra has little effect on heart development, whereas disrupting vdrb gene causes various cardiac phenotypes, characterized by pericardial edema, slower heart rate and laterality defects. Depletion of both vdra and vdrb (vdra/b) produce additive, but not synergistic effects. To determine whether atrioventricular (AV) cardiomyocytes are properly organized in these embryos, the expression of bmp4, which marks the developing AV boundary at 48 h post-fertilization, was examined. Notably, vdra/b-deficient embryos display ectopic expression of bmp4 towards the ventricle or throughout atrial and ventricular chambers. Taken together, these results suggest that VDR signaling plays an essential role in heart development. PMID:26797277

  11. Mitogen-activated protein kinase phosphatase is required for genotoxic stress relief in Arabidopsis

    OpenAIRE

    Ulm, Roman; Revenkova, Ekaterina; Di Sansebastiano, Gian-Pietro; Bechtold, Nicole; Paszkowski, Jerzy

    2001-01-01

    Genotoxic stress activates complex cellular responses allowing for the repair of DNA damage and proper cell recovery. Although plants are exposed constantly to increasing solar UV irradiation, the signaling cascades activated by genotoxic environments are largely unknown. We have identified an Arabidopsis mutant (mkp1) hypersensitive to genotoxic stress treatments (UV-C and methyl methanesulphonate) due to disruption of a gene that encodes an Arabidopsis homolog of mitogen-activated protein k...

  12. Early development of Drosophila embryos requires Smc5/6 function during oogenesis

    Directory of Open Access Journals (Sweden)

    Martin Tran

    2016-07-01

    Full Text Available Mutations in structural maintenance of chromosomes (Smc proteins are frequently associated with chromosomal abnormalities commonly observed in developmental disorders. However, the role of Smc proteins in development still remains elusive. To investigate Smc5/6 function during early embryogenesis we examined smc5 and smc6 mutants of the fruit fly Drosophila melanogaster using a combination of reverse genetics and microscopy approaches. Smc5/6 exhibited a maternally contributed function in maintaining chromosome stability during early embryo development, which manifested as female subfertility in its absence. Loss of Smc5/6 caused an arrest and a considerable delay in embryo development accompanied by fragmented nuclei and increased anaphase-bridge formation, respectively. Surprisingly, early embryonic arrest was attributable to the absence of Smc5/6 during oogenesis, which resulted in insufficient repair of pre-meiotic and meiotic DNA double-strand breaks. Thus, our findings contribute to the understanding of Smc proteins in higher eukaryotic development by highlighting a maternal function in chromosome maintenance and a link between oogenesis and early embryogenesis.

  13. Early development of Drosophila embryos requires Smc5/6 function during oogenesis.

    Science.gov (United States)

    Tran, Martin; Tsarouhas, Vasilios; Kegel, Andreas

    2016-01-01

    Mutations in structural maintenance of chromosomes (Smc) proteins are frequently associated with chromosomal abnormalities commonly observed in developmental disorders. However, the role of Smc proteins in development still remains elusive. To investigate Smc5/6 function during early embryogenesis we examined smc5 and smc6 mutants of the fruit fly Drosophila melanogaster using a combination of reverse genetics and microscopy approaches. Smc5/6 exhibited a maternally contributed function in maintaining chromosome stability during early embryo development, which manifested as female subfertility in its absence. Loss of Smc5/6 caused an arrest and a considerable delay in embryo development accompanied by fragmented nuclei and increased anaphase-bridge formation, respectively. Surprisingly, early embryonic arrest was attributable to the absence of Smc5/6 during oogenesis, which resulted in insufficient repair of pre-meiotic and meiotic DNA double-strand breaks. Thus, our findings contribute to the understanding of Smc proteins in higher eukaryotic development by highlighting a maternal function in chromosome maintenance and a link between oogenesis and early embryogenesis. PMID:27288507

  14. DELAYED FLOWERING, an Arabidopsis Gene That Acts in the Autonomous Flowering Promotion Pathway and Is Required for Normal Development

    Institute of Scientific and Technical Information of China (English)

    Ming-Jie Chen; Zheng Yuan; Hai Huang

    2006-01-01

    The control of flowering time in higher plants is one of the most important physiological processes and is critical for their reproductive success. To investigate the mechanisms controlling flowering time, we screened for Arabidopsis mutants with late-flowering phenotypes. One mutant, designated delayed flowering (dfr) in the Landsberg erecta (Ler) ecotype, was identified with delayed flowering time. Genetic analysis revealed that dfr is a single gene recessive nuclear mutant and the mutation was mapped to a locus tightly linked to UFO on chromosome 1. To our knowledge, no gene regulating flowering time has been reported yet in this region. The dfr mutant plant showed a delayed flowering time under the different growth conditions examined,including long- and short-day photoperiods and gibberellic acid GA3 treatments, suggesting that DFR is a gene involved in the autonomous flowering promotion pathway. The Arabidopsis gene FLOWERING LOCUS C (FLC) plays a central role in repressing flowering and its transcripts are undetectable in wild-type Ler.However, FLCexpression was upregulated in the dfrmutant, suggesting that DFR is a negative regulator of FLC. In addition, the dfr mutant plant displayed altered valve shapes of the silique and the number of trichomes and branches of each trichome were both reduced, indicating that the DRFgene is also required for normal plant development. Moreover, dfr leafy-5 (Ify-5) double mutant plants showed a much later flowering time than either dfr or Ify-5 single mutants, indicating that DFR and LFYact synergistically to promote flowering in Arabidopsis.

  15. Mitochondrial type-I prohibitins of Arabidopsis thaliana are required for supporting proficient meristem development

    Czech Academy of Sciences Publication Activity Database

    Van Aken, O.; Pečenková, Tamara; van de Cotte, B.; De Rycke, R.; Eeckhout, D.; Fromm, H.; De Jaeger, G.; Witters, E.; Beemster, G.T.S.; Inzé, D.; Van Breusegem, F.

    2007-01-01

    Roč. 52, č. 5 (2007), s. 850-864. ISSN 0960-7412 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arabidopsis * prohibitins * mitochondria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.751, year: 2007

  16. Peroxidase-dependent apoplastic oxidative burst in Arabidopsis required for pathogen resistance.

    Science.gov (United States)

    Bindschedler, Laurence V; Dewdney, Julia; Blee, Kris A; Stone, Julie M; Asai, Tsuneaki; Plotnikov, Julia; Denoux, Carine; Hayes, Tezni; Gerrish, Chris; Davies, Dewi R; Ausubel, Frederick M; Bolwell, G Paul

    2006-09-01

    The oxidative burst is an early response to pathogen attack leading to the production of reactive oxygen species (ROS) including hydrogen peroxide. Two major mechanisms involving either NADPH oxidases or peroxidases that may exist singly or in combination in different plant species have been proposed for the generation of ROS. We identified an Arabidopsis thaliana azide-sensitive but diphenylene iodonium-insensitive apoplastic oxidative burst that generates H(2)O(2) in response to a Fusarium oxysporum cell-wall preparation. Transgenic Arabidopsis plants expressing an anti-sense cDNA encoding a type III peroxidase, French bean peroxidase type 1 (FBP1) exhibited an impaired oxidative burst and were more susceptible than wild-type plants to both fungal and bacterial pathogens. Transcriptional profiling and RT-PCR analysis showed that the anti-sense (FBP1) transgenic plants had reduced levels of specific peroxidase-encoding mRNAs, including mRNAs corresponding to Arabidopsis genes At3g49120 (AtPCb) and At3g49110 (AtPCa) that encode two class III peroxidases with a high degree of homology to FBP1. These data indicate that peroxidases play a significant role in generating H(2)O(2) during the Arabidopsis defense response and in conferring resistance to a wide range of pathogens. PMID:16889645

  17. The Nanos3-3'UTR is required for germ cell specific NANOS3 expression in mouse embryos.

    Directory of Open Access Journals (Sweden)

    Hitomi Suzuki

    Full Text Available BACKGROUND: The regulation of gene expression via a 3' untranslated region (UTR plays essential roles in the discrimination of the germ cell lineage from somatic cells during embryogenesis. This is fundamental to the continuation of a species. Mouse NANOS3 is an essential protein required for the germ cell maintenance and is specifically expressed in these cells. However, the regulatory mechanisms that restrict the expression of this gene in the germ cells is largely unknown at present. METHODOLOGY/PRINCIPAL FINDINGS: In our current study, we show that differences in the stability of Nanos3 mRNA between germ cells and somatic cells is brought about in a 3'UTR-dependent manner in mouse embryos. Although Nanos3 is transcribed in both cell lineages, it is efficiently translated only in the germ lineage. We also find that the translational suppression of NANOS3 in somatic cells is caused by a 3'UTR-mediated mRNA destabilizing mechanism. Surprisingly, even when under the control of the CAG promoter which induces strong ubiquitous transcription in both germ cells and somatic cells, the addition of the Nanos3-3'UTR sequence to the coding region of exogenous gene was effective in restricting protein expression in germ cells. CONCLUSIONS/SIGNIFICANCE: Our current study thus suggests that Nanos3-3'UTR has an essential role in translational control in the mouse embryo.

  18. GRP78 is required for cell proliferation and protection from apoptosis in chicken embryo fibroblast cells.

    Science.gov (United States)

    Jeon, M; Choi, H; Lee, S I; Kim, J S; Park, M; Kim, K; Lee, S; Byun, S J

    2016-05-01

    Chicken serum has been suggested as a supplement to promote chicken cell proliferation and development. However, the molecular mechanisms by which chicken serum stimulates chicken cell proliferation remain unknown. Here, we evaluated the effects of chicken serum supplementation on chicken embryo fibroblast (CEF) and DF-1 cell proliferation. We also sought to elucidate the molecular pathways involved in mediating the effects of chicken serum on fibroblasts and DF-1 cells by overexpression of chicken 78 kDa glucose-regulated protein (chGRP78), which is important for cell growth and the prevention of apoptosis. Our data demonstrated that the addition of 5% chicken serum significantly enhanced fibroblast proliferation. Moreover, knockdown of chGRP78 using siRNA decreased fibroblast proliferation and increased apoptosis. Based on these results, we suggest that the chGRP78-mediated signaling pathway plays a critical role in chicken serum-stimulated fibroblast survival and anti-apoptosis. Therefore, our findings have important implications for the maintenance of chicken fibroblast cells through the inhibition of apoptosis and may lead to the development of new treatments for avian disease. PMID:26944959

  19. Cleavage of Model Substrates by Arabidopsis thaliana PRORP1 Reveals New Insights into Its Substrate Requirements.

    Science.gov (United States)

    Mao, Guanzhong; Chen, Tien-Hao; Srivastava, Abhishek S; Kosek, David; Biswas, Pradip K; Gopalan, Venkat; Kirsebom, Leif A

    2016-01-01

    Two broad classes of RNase P trim the 5' leader of precursor tRNAs (pre-tRNAs): ribonucleoprotein (RNP)- and proteinaceous (PRORP)-variants. These two RNase P types, which use different scaffolds for catalysis, reflect independent evolutionary paths. While the catalytic RNA-based RNP form is present in all three domains of life, the PRORP family is restricted to eukaryotes. To obtain insights on substrate recognition by PRORPs, we examined the 5' processing ability of recombinant Arabidopsis thaliana PRORP1 (AtPRORP1) using a panel of pre-tRNASer variants and model hairpin-loop derivatives (pATSer type) that consist of the acceptor-T-stem stack and the T-/D-loop. Our data indicate the importance of the identity of N-1 (the residue immediately 5' to the cleavage site) and the N-1:N+73 base pair for cleavage rate and site selection of pre-tRNASer and pATSer. The nucleobase preferences that we observed mirror the frequency of occurrence in the complete suite of organellar pre-tRNAs in eight algae/plants that we analyzed. The importance of the T-/D-loop in pre-tRNASer for tight binding to AtPRORP1 is indicated by the 200-fold weaker binding of pATSer compared to pre-tRNASer, while the essentiality of the T-loop for cleavage is reflected by the near-complete loss of activity when a GAAA-tetraloop replaced the T-loop in pATSer. Substituting the 2'-OH at N-1 with 2'-H also resulted in no detectable cleavage, hinting at the possible role of this 2'-OH in coordinating Mg2+ ions critical for catalysis. Collectively, our results indicate similarities but also key differences in substrate recognition by the bacterial RNase P RNP and AtPRORP1: while both forms exploit the acceptor-T-stem stack and the elbow region in the pre-tRNA, the RNP form appears to require more recognition determinants for cleavage-site selection. PMID:27494328

  20. Cleavage of Model Substrates by Arabidopsis thaliana PRORP1 Reveals New Insights into Its Substrate Requirements

    Science.gov (United States)

    Srivastava, Abhishek S.; Kosek, David; Biswas, Pradip K.; Gopalan, Venkat; Kirsebom, Leif A.

    2016-01-01

    Two broad classes of RNase P trim the 5' leader of precursor tRNAs (pre-tRNAs): ribonucleoprotein (RNP)- and proteinaceous (PRORP)-variants. These two RNase P types, which use different scaffolds for catalysis, reflect independent evolutionary paths. While the catalytic RNA-based RNP form is present in all three domains of life, the PRORP family is restricted to eukaryotes. To obtain insights on substrate recognition by PRORPs, we examined the 5' processing ability of recombinant Arabidopsis thaliana PRORP1 (AtPRORP1) using a panel of pre-tRNASer variants and model hairpin-loop derivatives (pATSer type) that consist of the acceptor-T-stem stack and the T-/D-loop. Our data indicate the importance of the identity of N-1 (the residue immediately 5' to the cleavage site) and the N-1:N+73 base pair for cleavage rate and site selection of pre-tRNASer and pATSer. The nucleobase preferences that we observed mirror the frequency of occurrence in the complete suite of organellar pre-tRNAs in eight algae/plants that we analyzed. The importance of the T-/D-loop in pre-tRNASer for tight binding to AtPRORP1 is indicated by the 200-fold weaker binding of pATSer compared to pre-tRNASer, while the essentiality of the T-loop for cleavage is reflected by the near-complete loss of activity when a GAAA-tetraloop replaced the T-loop in pATSer. Substituting the 2'-OH at N-1 with 2'-H also resulted in no detectable cleavage, hinting at the possible role of this 2'-OH in coordinating Mg2+ ions critical for catalysis. Collectively, our results indicate similarities but also key differences in substrate recognition by the bacterial RNase P RNP and AtPRORP1: while both forms exploit the acceptor-T-stem stack and the elbow region in the pre-tRNA, the RNP form appears to require more recognition determinants for cleavage-site selection. PMID:27494328

  1. An Arabidopsis flavonoid transporter is required for anther dehiscence and pollen development

    OpenAIRE

    Thompson, Elinor P.; Wilkins, Christopher; Demidchik, Vadim; Davies, Julia M; Glover, Beverley J.

    2010-01-01

    FLOWER FLAVONOID TRANSPORTER (FFT) encodes a multidrug and toxin efflux family transporter in Arabidopsis thaliana. FFT (AtDTX35) is highly transcribed in floral tissues, the transcript being localized to epidermal guard cells, including those of the anthers, stigma, siliques and nectaries. Mutant analysis demonstrates that the absence of FFT transcript affects flavonoid levels in the plant and that the altered flavonoid metabolism has wide-ranging consequences. Root growth, seed development ...

  2. The Arabidopsis Golgi-localized GDP-L-fucose transporter is required for plant development

    OpenAIRE

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng; Stonebloom, Solomon; Smith-Moritz, Andreia M.; Pauly, Markus; Orellana, Ariel; Scheller, Henrik Vibe; Heazlewood, Joshua L.

    2016-01-01

    Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rh...

  3. The Recovery of Plastid Function Is Required for Optimal Response to Low Temperatures in Arabidopsis

    OpenAIRE

    Kindgren, Peter; Dubreuil, Carole; Strand, Åsa

    2015-01-01

    Cold acclimation is an essential response in higher plants to survive freezing temperatures. Here, we report that two independent mutant alleles of the H-subunit of Mg-chelatase, CHLH, gun5-1 and cch in Arabidopsis are sensitive to low temperatures. Plants were grown in photoperiodic conditions and exposed to low temperatures for short-and long-term periods. Tetrapyrrole biosynthesis was initially significantly inhibited in response to low temperature but recovered in wild type (Col-0), altho...

  4. Requirement of KNAT1/BP for the Development of Abscission Zones in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qun Wang; Wei-Hui Xu; Li-Geng Ma; Zhi-Ming Fu; Xing-Wang Deng; Jia-Yang Li; Yong-Hong Wang

    2006-01-01

    The KNAT1 gene is a member of the Class Ⅰ KNOXhomeobox gene family and is thought to play an important role in meristem development and leaf morphogenesis. Recent studies have demonstrated that KNAT1/BP regulates the architecture of the inflorescence by affecting pedicle development in Arabidopsis thaliana.Herein, we report the characterization of an Arabidopsis T-DNA insertion mutant that shares considerable phenotypic similarity to the previously identified mutant brevipedicle (bp). Molecular and genetic analyses showed that the mutant is allelic to bp and that the T-DNA is located within the first helix of the KNAT1homeodomain (HD). Although the mutation causes a typical abnormality of short pedicles, propendent siliques,and semidwarfism, no obvious defects are observed in the vegetative stage. A study on cell morphology showed that asymmetrical division and inhibition of cell elongation contribute to the downward-pointing and shorter pedicle phenotype. Loss of KNAT/BPfunction results in the abnormal development of abscission zones. Microarray analysis of gene expression profiling suggests that KNAT1/BP may regulate abscission zone development through hormone signaling and hormone metabolism in Arabidopsis.

  5. Evolutionarily distant pathogens require the Arabidopsis phytosulfokine signalling pathway to establish disease.

    Science.gov (United States)

    Rodiuc, Natalia; Barlet, Xavier; Hok, Sophie; Perfus-Barbeoch, Laetitia; Allasia, Valérie; Engler, Gilbert; Séassau, Aurélie; Marteu, Nathalie; de Almeida-Engler, Janice; Panabières, Franck; Abad, Pierre; Kemmerling, Birgit; Marco, Yves; Favery, Bruno; Keller, Harald

    2016-07-01

    Secreted peptides and their specific receptors frequently orchestrate cell-to-cell communication in plants. Phytosulfokines (PSKs) are secreted tyrosine-sulphated peptide hormones, which trigger cellular dedifferentiation and redifferentiation upon binding to their membrane receptor. Biotrophic plant pathogens frequently trigger the differentiation of host cells into specialized feeding structures, which are essential for successful infection. We found that oomycete and nematode infections were characterized by the tissue-specific transcriptional regulation of genes encoding Arabidopsis PSKs and the PSK receptor 1 (PSKR1). Subcellular analysis of PSKR1 distribution showed that the plasma membrane-bound receptor internalizes after binding of PSK-α. Arabidopsis pskr1 knockout mutants were impaired in their susceptibility to downy mildew infection. Impaired disease susceptibility depends on functional salicylic acid (SA) signalling, but not on the massive up-regulation of SA-associated defence-related genes. Knockout pskr1 mutants also displayed a major impairment of root-knot nematode reproduction. In the absence of functional PSKR1, giant cells arrested their development and failed to fully differentiate. Our findings indicate that the observed restriction of PSK signalling to cells surrounding giant cells contributes to the isotropic growth and maturation of nematode feeding sites. Taken together, our data suggest that PSK signalling in Arabidopsis promotes the differentiation of host cells into specialized feeding cells. PMID:26290138

  6. Cloning and characterization of a gene (UVR3) required for photorepair of 6-4 photoproducts in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    UV radiation induces two major classes of pyrimidine dimers: the pyrimidine [6-4] pyrimidone photoproduct (6-4 product) and the cyclobutane pyrimidine dimer (CPD). Many organisms produce enzymes, termed photolyases, that specifically bind to these damage products and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. A gene that expresses a protein with 6-4 photolyase activity in vitro was recently cloned from Drosophila melanogaster and Xenopus laevis. We report here the isolation of a homolog of this gene, cloned on the basis of sequence similarity, from the higher plant Arabidopsis thaliana. This cloned gene produces a protein with 6-4 photolyase activity when expressed in Escherichia coli. We also find that a previously described mutant of Arabidopsis (uvr3) that is defective in photoreactivation of 6-4 products carries a nonsense mutation in this 6-4 photolyase homolog. We have therefore termed this gene UVR3. Although homologs of this gene have previously been shown to produce a functional 6-4 photolyase when expressed in heterologous systems, this is the first demonstration of a requirement for this gene for photoreactivation of 6-4 products in vivo

  7. Arabidopsis MSI1 Is Required for Negative Regulation of the Response to Drought Stress

    Institute of Scientific and Technical Information of China (English)

    Cristina Alexandre; Yvonne M(o)ller-Steinbach; Nicole Sch(o)nrock; Wilhelm Gruissem; Lars Hennig

    2009-01-01

    Arabidopsis MSI1 has fundamental functions in plant development.MSI1 is a subunit of Polycomb group protein complexes and Chromatin assembly factor 1,and it interacts with the Retinoblastoma-related protein 1.Altered levels of MSI1 result in pleiotropic phenotypes,reflecting the complexity of MSI1 protein functions.In order to uncover additional functions of MSI1,we performed transcriptional profiling of wild-type and plants with highly reduced MSI1 levels (msil-cs).Surprisingly,the known functions of MSI1 could only account for a minor part of the transcriptional changes in msi1-cs plants.One of the most striking unexpected observations was the up-regulation of a subset of ABA-responsive genes eliciting the response to drought and salt stress.We report that MSI1 can bind to the chromatin of the drought-inducible downstream target RD20 and suggest a new role for MSI1 in the negative regulation of the Arabidopsis drought-stress response.

  8. Arabidopsis VARIEGATED 3 encodes a chloroplasttargeted, zinc-finger protein required for chloroplast and palisade cell development

    DEFF Research Database (Denmark)

    Næsted, Henrik; Holm, A.; Jenkins, T.; Nielsen, H.B.; Harris, C.A.; Beale, M.H.; Andersen, M.; Mant, A.; Scheller, H.; Camara, B.; Mattsson, O.; Mundy, J.

    2004-01-01

    The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 pro...... pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development....... protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that...

  9. Repression of AS2 by WOX family transcription factors is required for leaf development in Medicago and Arabidopsis.

    Science.gov (United States)

    Zhang, Fei; Tadege, Million

    2015-01-01

    WOX transcription factors are key regulators of meristematic activity in plants. The Medicago WOX gene, STF, functions in maintenance of leaf marginal meristem, analogous to the function of WUS in the shoot apical meristem. Both STF and WUS directly repress AS2 expression in their respective domains. Ectopic expression of AS2 with WUS promoter leads to a narrow leaf phenotype and other phenotypes similar to the wus mutant. We also found that a wox1 prs wus triple mutant produces much narrower leaf blades than the wox1 prs double mutant, indicating that WUS genetically interacts with WOX1 and PRS in Arabidopsis leaf blade development. Our data points to a general requirement for AS2 repression in meristematic regions to allow cell proliferation. PMID:25807065

  10. Rhizobacteria-mediated induced systemic resistance (ISR) in Arabidopsis requires sensitivity to jasmonate and ethylene but is not accompanied by an increase in their production

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Pelt, J.A. van; Ton, J.; Parchmann, S.; Mueller, M.J.; Buchala, A.J.; Métraux, J.P.; Loon, L.C. van

    2000-01-01

    Plants develop an enhanced defensive capacity against a broad spectrum of plant pathogens after colonization of the roots by selected strains of nonpathogenic biocontrol bacteria. In Arabidopsis thaliana, this induced systemic resistance (ISR) functions independently of salicylic acid but requires a

  11. PROTEIN TARGETING TO STARCH is required for localising GRANULE-BOUND STARCH SYNTHASE to starch granules and for normal amylose synthesis in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    David Seung

    2015-02-01

    Full Text Available The domestication of starch crops underpinned the development of human civilisation, yet we still do not fully understand how plants make starch. Starch is composed of glucose polymers that are branched (amylopectin or linear (amylose. The amount of amylose strongly influences the physico-chemical behaviour of starchy foods during cooking and of starch mixtures in non-food manufacturing processes. The GRANULE-BOUND STARCH SYNTHASE (GBSS is the glucosyltransferase specifically responsible for elongating amylose polymers and was the only protein known to be required for its biosynthesis. Here, we demonstrate that PROTEIN TARGETING TO STARCH (PTST is also specifically required for amylose synthesis in Arabidopsis. PTST is a plastidial protein possessing an N-terminal coiled coil domain and a C-terminal carbohydrate binding module (CBM. We discovered that Arabidopsis ptst mutants synthesise amylose-free starch and are phenotypically similar to mutants lacking GBSS. Analysis of granule-bound proteins showed a dramatic reduction of GBSS protein in ptst mutant starch granules. Pull-down assays with recombinant proteins in vitro, as well as immunoprecipitation assays in planta, revealed that GBSS physically interacts with PTST via a coiled coil. Furthermore, we show that the CBM domain of PTST, which mediates its interaction with starch granules, is also required for correct GBSS localisation. Fluorescently tagged Arabidopsis GBSS, expressed either in tobacco or Arabidopsis leaves, required the presence of Arabidopsis PTST to localise to starch granules. Mutation of the CBM of PTST caused GBSS to remain in the plastid stroma. PTST fulfils a previously unknown function in targeting GBSS to starch. This sheds new light on the importance of targeting biosynthetic enzymes to sub-cellular sites where their action is required. Importantly, PTST represents a promising new gene target for the biotechnological modification of starch composition, as it is

  12. Male Sterile2 Encodes a Plastid-Localized Fatty Acyl Carrier Protein Reductase Required for Pollen Exine Development in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.; Shanklin, J.; Yu, X.-H.; Zhang, K.; Shi, J.; De Oliveira, S.; Schreiber, L.; Zhang, D.

    2011-10-01

    Male Sterile2 (MS2) is predicted to encode a fatty acid reductase required for pollen wall development in Arabidopsis (Arabidopsis thaliana). Transient expression of MS2 in tobacco (Nicotiana benthamiana) leaves resulted in the accumulation of significant levels of C16 and C18 fatty alcohols. Expression of MS2 fused with green fluorescent protein revealed that an amino-terminal transit peptide targets the MS2 to plastids. The plastidial localization of MS2 is biologically important because genetic complementation of MS2 in ms2 homozygous plants was dependent on the presence of its amino-terminal transit peptide or that of the Rubisco small subunit protein amino-terminal transit peptide. In addition, two domains, NAD(P)H-binding domain and sterile domain, conserved in MS2 and its homologs were also shown to be essential for MS2 function in pollen exine development by genetic complementation testing. Direct biochemical analysis revealed that purified recombinant MS2 enzyme is able to convert palmitoyl-Acyl Carrier Protein to the corresponding C16:0 alcohol with NAD(P)H as the preferred electron donor. Using optimized reaction conditions (i.e. at pH 6.0 and 30 C), MS2 exhibits a K{sub m} for 16:0-Acyl Carrier Protein of 23.3 {+-} 4.0 {mu}m, a V{sub max} of 38.3 {+-} 4.5 nmol mg{sup -1} min{sup -1}, and a catalytic efficiency/K{sub m} of 1,873 m{sup -1} s{sup -1}. Based on the high homology of MS2 to other characterized fatty acid reductases, it was surprising that MS2 showed no activity against palmitoyl- or other acyl-coenzyme A; however, this is consistent with its plastidial localization. In summary, genetic and biochemical evidence demonstrate an MS2-mediated conserved plastidial pathway for the production of fatty alcohols that are essential for pollen wall biosynthesis in Arabidopsis.

  13. Arabidopsis R-SNARE proteins VAMP721 and VAMP722 are required for cell plate formation.

    Directory of Open Access Journals (Sweden)

    Liang Zhang

    Full Text Available BACKGROUND: Cell plate formation during plant cytokinesis is facilitated by SNARE complex-mediated vesicle fusion at the cell-division plane. However, our knowledge regarding R-SNARE components of membrane fusion machinery for cell plate formation remains quite limited. METHODOLOGY/PRINCIPAL FINDINGS: We report the in vivo function of Arabidopsis VAMP721 and VAMP722, two closely sequence-related R-SNAREs, in cell plate formation. Double homozygous vamp721vamp722 mutant seedlings showed lethal dwarf phenotypes and were characterized by rudimentary roots, cotyledons and hypocotyls. Furthermore, cell wall stubs and incomplete cytokinesis were frequently observed in vamp721vamp722 seedlings. Confocal images revealed that green fluorescent protein-tagged VAMP721 and VAMP722 were preferentially localized to the expanding cell plates in dividing cells. Drug treatments and co-localization analyses demonstrated that punctuate organelles labeled with VAMP721 and VAMP722 represented early endosomes overlapped with VHA-a1-labeled TGN, which were distinct from Golgi stacks and prevacuolar compartments. In addition, protein traffic to the plasma membrane, but not to the vacuole, was severely disrupted in vamp721vamp722 seedlings by subcellular localization of marker proteins. CONCLUSION/SIGNIFICANCE: These observations suggest that VAMP721 and VAMP722 are involved in secretory trafficking to the plasma membrane via TGN/early endosomal compartment, which contributes substantially to cell plate formation during plant cytokinesis.

  14. MYB103 is required for FERULATE-5-HYDROXYLASE expression and syringyl lignin biosynthesis in Arabidopsis stems.

    Science.gov (United States)

    Öhman, David; Demedts, Brecht; Kumar, Manoj; Gerber, Lorenz; Gorzsás, András; Goeminne, Geert; Hedenström, Mattias; Ellis, Brian; Boerjan, Wout; Sundberg, Björn

    2013-01-01

    The transcription factor MYB103 was previously identified as a member of the transcriptional network regulating secondary wall biosynthesis in xylem tissues of Arabidopsis, and was proposed to act on cellulose biosynthesis. It is a direct transcriptional target of the transcription factor SECONDARY WALL ASSOCIATED NAC DOMAIN PROTEIN 1 (SND1), and 35S-driven dominant repression or over-expression of MYB103 modifies secondary wall thickness. We identified two myb103 T-DNA insertion mutants and chemically characterized their lignocellulose by pyrolysis/GC/MS, 2D NMR, FT-IR microspectroscopy and wet chemistry. The mutants developed normally but exhibited a 70-75% decrease in syringyl (S) lignin. The level of guaiacyl (G) lignin was co-ordinately increased, so that total Klason lignin was not affected. The transcript abundance of FERULATE-5-HYDROXYLASE (F5H), the key gene in biosynthesis of S lignin, was strongly decreased in the myb103 mutants, and the metabolomes of the myb103 mutant and an F5H null mutant were very similar. Other than modification of the lignin S to G ratio, there were only very minor changes in the composition of secondary cell-wall polymers in the inflorescence stem. In conclusion, we demonstrate that F5H expression and hence biosynthesis of S lignin are dependent on MYB103. PMID:22967312

  15. Gibberellic acid signaling is required for ambient temperature-mediated induction of flowering in Arabidopsis thaliana.

    Science.gov (United States)

    Galvão, Vinicius Costa; Collani, Silvio; Horrer, Daniel; Schmid, Markus

    2015-12-01

    Distinct molecular mechanisms integrate changes in ambient temperature into the genetic pathways that govern flowering time in Arabidopsis thaliana. Temperature-dependent eviction of the histone variant H2A.Z from nucleosomes has been suggested to facilitate the expression of FT by PIF4 at elevated ambient temperatures. Here we show that, in addition to PIF4, PIF3 and PIF5, but not PIF1 and PIF6, can promote flowering when expressed specifically in phloem companion cells (PCC), where they can induce FT and its close paralog, TSF. However, despite their strong potential to promote flowering, genetic analyses suggest that the PIF genes seem to have only a minor role in adjusting flowering in response to photoperiod or high ambient temperature. In addition, loss of PIF function only partially suppressed the early flowering phenotype and FT expression of the arp6 mutant, which is defective in H2A.Z deposition. In contrast, the chemical inhibition of gibberellic acid (GA) biosynthesis resulted in a strong attenuation of early flowering and FT expression in arp6. Furthermore, GA was able to induce flowering at low temperature (15°C) independently of FT, TSF, and the PIF genes, probably directly at the shoot apical meristem. Together, our results suggest that the timing of the floral transition in response to ambient temperature is more complex than previously thought and that GA signaling might play a crucial role in this process. PMID:26466761

  16. Endogenous salicylic acid is required for promoting cadmium tolerance of Arabidopsis by modulating glutathione metabolisms.

    Science.gov (United States)

    Guo, Bin; Liu, Chen; Li, Hua; Yi, Keke; Ding, Nengfei; Li, Ningyu; Lin, Yicheng; Fu, Qinglin

    2016-10-01

    A few studies with NahG transgenic lines of Arabidopsis show that depletion of SA enhances cadmium (Cd) tolerance. However, it remains some uncertainties that the defence signaling may be a result of catechol accumulation in NahG transgenic lines but not SA deficiency. Here, we conducted a set of hydroponic assays with another SA-deficient mutant sid2 to examine the endogenous roles of SA in Cd tolerance, especially focusing on the glutathione (GSH) cycling. Our results showed that reduced SA resulted in negative effects on Cd tolerance, including decreased Fe uptake and chlorophyll concentration, aggravation of oxidative damage and growth inhibition. Cd exposure significantly increased SA concentration in wild-type leaves, but did not affect it in sid2 mutants. Depletion of SA did not disturb the Cd uptake in either roots or shoots. The reduced Cd tolerance in sid2 mutants is due to the lowered GSH status, which is associated with the decreased expression of serine acetyltransferase along with a decline in contents of non-protein thiols, phytochelatins, and the lowered transcription and activities of glutathione reductase1 (GR1) which reduced GSH regeneration. Finally, the possible mode of SA signaling through the GR/GSH pathway during Cd exposure is discussed. PMID:27209521

  17. HYL1 is required for establishment of stamen architecture with four microsporangia in Arabidopsis.

    Science.gov (United States)

    Lian, Heng; Li, Xiaorong; Liu, Zhongyuan; He, Yuke

    2013-08-01

    The stamen produces pollen grains for pollination in higher plants. Coordinated development of four microsporangia in the stamen is essential for normal fertility. The roles of miR165/166-directed pathways in the establishment of adaxial-abaxial polarity have been well defined in leaves. However, the molecular mechanism underlying the adaxial-abaxial polarity of the stamen is elusive. Here it is reported that HYPONASTIC LEAVES1 (HYL1), a general regulator of microRNA (miRNA) biogenesis, plays an essential role in establishing the stamen architecture of the four microsporangia in Arabidopsis thaliana. In stamens, HYL1 and miR165/6 expression are progressively restricted to the lateral region, microsporangia, microspore mother cells, and microspores, whereas HD-ZIP III genes are preferentially expressed in the middle region, vascular bundle, and stomium. Loss of HYL1 leads to the formation of two rather than four microsporangia in each stamen. In the stamen of the hyl1 mutant, miR165/6 accumulation is reduced, whereas miR165/6-targeted HD-ZIP III genes are up-regulated and FILAMENTOUS FLOWER (FIL) is down-regulated; and, specifically, REVOLUTA (REV) is overexpressed in the adaxial region and FIL is underexpressed in the abaxial regions, concomitant with the aberrance of the two inner microsporangia and partial adaxialization of the connectives. Genetic analysis reveals that FIL works downstream of HYL1, and the defects in hyl1 stamens are partially rescued by rev-9 or phv-5 phb-6 alleles. These results suggest that HYL1 modulates inner microsporangia and stamen architecture by repression of HD-ZIP III genes and promotion of the FIL gene through miR165/6. Thus, the role of HYL1 in establishment of stamen architecture provides insight into the molecular mechanism of male fertility. PMID:23918970

  18. Arabidopsis GERANYLGERANYL DIPHOSPHATE SYNTHASE 11 is a hub isozyme required for the production of most photosynthesis-related isoprenoids.

    Science.gov (United States)

    Ruiz-Sola, M Águila; Coman, Diana; Beck, Gilles; Barja, M Victoria; Colinas, Maite; Graf, Alexander; Welsch, Ralf; Rütimann, Philipp; Bühlmann, Peter; Bigler, Laurent; Gruissem, Wilhelm; Rodríguez-Concepción, Manuel; Vranová, Eva

    2016-01-01

    Most plastid isoprenoids, including photosynthesis-related metabolites such as carotenoids and the side chain of chlorophylls, tocopherols (vitamin E), phylloquinones (vitamin K), and plastoquinones, derive from geranylgeranyl diphosphate (GGPP) synthesized by GGPP synthase (GGPPS) enzymes. Seven out of 10 functional GGPPS isozymes in Arabidopsis thaliana reside in plastids. We aimed to address the function of different GGPPS paralogues for plastid isoprenoid biosynthesis. We constructed a gene co-expression network (GCN) using GGPPS paralogues as guide genes and genes from the upstream and downstream pathways as query genes. Furthermore, knock-out and/or knock-down ggpps mutants were generated and their growth and metabolic phenotypes were analyzed. Also, interacting protein partners of GGPPS11 were searched for. Our data showed that GGPPS11, encoding the only plastid isozyme essential for plant development, functions as a hub gene among GGPPS paralogues and is required for the production of all major groups of plastid isoprenoids. Furthermore, we showed that the GGPPS11 protein physically interacts with enzymes that use GGPP for the production of carotenoids, chlorophylls, tocopherols, phylloquinone, and plastoquinone. GGPPS11 is a hub isozyme required for the production of most photosynthesis-related isoprenoids. Both gene co-expression and protein-protein interaction likely contribute to the channeling of GGPP by GGPPS11. PMID:26224411

  19. The role of auxin signaling in early embryo pattern formation

    NARCIS (Netherlands)

    Smit, Margot E.; Weijers, Dolf

    2015-01-01

    Pattern formation of the early Arabidopsis embryo generates precursors to all major cell types, and is profoundly controlled by the signaling molecule auxin. Here we discuss recent milestones in our understanding of auxin-dependent embryo patterning. Auxin biosynthesis, transport and response mec

  20. Rat embryo fibroblasts require both the cell-binding and the heparin-binding domains of fibronectin for survival

    DEFF Research Database (Denmark)

    Jeong, J; Han, I; Lim, Y;

    2001-01-01

    of the cell-binding domain of FN with integrin is sufficient to rescue rat embryo fibroblasts (REFs) from detachment-induced apoptosis. REFs attached and spread normally after plating on substrates coated with either intact FN or a FN fragment, FN120, that contains the cell-binding domain but lacks the C-terminal...

  1. The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Kee Hoon Sohn

    2014-10-01

    Full Text Available Plant nucleotide-binding leucine-rich repeat (NB-LRR disease resistance (R proteins recognize specific "avirulent" pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs. How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4 and RRS1 (resistance to Ralstonia solanacearum 1, function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NB-LRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1 mutant encodes an RRS1 allele (RRS1SLH1 with a single amino acid (leucine insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed

  2. The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana.

    Science.gov (United States)

    Sohn, Kee Hoon; Segonzac, Cécile; Rallapalli, Ghanasyam; Sarris, Panagiotis F; Woo, Joo Yong; Williams, Simon J; Newman, Toby E; Paek, Kyung Hee; Kobe, Bostjan; Jones, Jonathan D G

    2014-10-01

    Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific "avirulent" pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NB-LRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light

  3. The Evolutionarily Conserved Protein PHOTOSYNTHESIS AFFECTED MUTANT71 Is Required for Efficient Manganese Uptake at the Thylakoid Membrane in Arabidopsis.

    Science.gov (United States)

    Schneider, Anja; Steinberger, Iris; Herdean, Andrei; Gandini, Chiara; Eisenhut, Marion; Kurz, Samantha; Morper, Anna; Hoecker, Natalie; Rühle, Thilo; Labs, Mathias; Flügge, Ulf-Ingo; Geimer, Stefan; Schmidt, Sidsel Birkelund; Husted, Søren; Weber, Andreas P M; Spetea, Cornelia; Leister, Dario

    2016-04-01

    In plants, algae, and cyanobacteria, photosystem II (PSII) catalyzes the light-driven oxidation of water. The oxygen-evolving complex of PSII is a Mn4CaO5 cluster embedded in a well-defined protein environment in the thylakoid membrane. However, transport of manganese and calcium into the thylakoid lumen remains poorly understood. Here, we show that Arabidopsis thaliana PHOTOSYNTHESIS AFFECTED MUTANT71 (PAM71) is an integral thylakoid membrane protein involved in Mn(2+) and Ca(2+) homeostasis in chloroplasts. This protein is required for normal operation of the oxygen-evolving complex (as evidenced by oxygen evolution rates) and for manganese incorporation. Manganese binding to PSII was severely reduced in pam71 thylakoids, particularly in PSII supercomplexes. In cation partitioning assays with intact chloroplasts, Mn(2+) and Ca(2+) ions were differently sequestered in pam71, with Ca(2+) enriched in pam71 thylakoids relative to the wild type. The changes in Ca(2+) homeostasis were accompanied by an increased contribution of the transmembrane electrical potential to the proton motive force across the thylakoid membrane. PSII activity in pam71 plants and the corresponding Chlamydomonas reinhardtii mutant cgld1 was restored by supplementation with Mn(2+), but not Ca(2+) Furthermore, PAM71 suppressed the Mn(2+)-sensitive phenotype of the yeast mutant Δpmr1 Therefore, PAM71 presumably functions in Mn(2+) uptake into thylakoids to ensure optimal PSII performance. PMID:27020959

  4. Integration of hormonal signaling networks and mobile microRNAs is required for vascular patterning in Arabidopsis roots

    KAUST Repository

    Muraro, D.

    2013-12-31

    As multicellular organisms grow, positional information is continually needed to regulate the pattern in which cells are arranged. In the Arabidopsis root, most cell types are organized in a radially symmetric pattern; however, a symmetry-breaking event generates bisymmetric auxin and cytokinin signaling domains in the stele. Bidirectional cross-talk between the stele and the surrounding tissues involving a mobile transcription factor, SHORT ROOT (SHR), and mobile microRNA species also determines vascular pattern, but it is currently unclear how these signals integrate. We use a multicellular model to determine a minimal set of components necessary for maintaining a stable vascular pattern. Simulations perturbing the signaling network show that, in addition to the mutually inhibitory interaction between auxin and cytokinin, signaling through SHR, microRNA165/6, and PHABULOSA is required to maintain a stable bisymmetric pattern. We have verified this prediction by observing loss of bisymmetry in shr mutants. The model reveals the importance of several features of the network, namely the mutual degradation of microRNA165/6 and PHABULOSA and the existence of an additional negative regulator of cytokinin signaling. These components form a plausible mechanism capable of patterning vascular tissues in the absence of positional inputs provided by the transport of hormones from the shoot.

  5. Induction of defence gene expression by oligogalacturonic acid requires increases in both cytosolic calcium and hydrogen peroxide in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Xiang Yang HU; Steven J NEILL; Wei Ming CAI; Zhang Cheng TANG

    2004-01-01

    Responses to oligogalacturonic acid (OGA) were determined in transgenic Arabidopsis thaliana seedlings expressing the calcium reporter protein aequorin. OGA stimulated a rapid, substantial and transient increase in the concentration of cytosolic calcium ([Ca2+]cyt) that peaked after ca. 15 s. This increase was dose-dependent, saturating at ca. 50 μg Gal equiv/ml of OGA. OGA also stimulated a rapid generation of H2O2. A small, rapid increase in H2O2 content was followed by a much larger oxidative burst, with H2O2 content peaking after ca. 60 min and declining thereafter. Induction of the oxidative burst by OGA was also dose-dependent, with a maximum response again being achieved at ca. 50 μg Gal equiv/mL. Inhibitors of calcium fluxes inhibited both increases in [Ca2+]cyt and [H2O2], whereas inhibitors of NADPH oxidase blocked only the oxidative burst. OGA increased strongly the expression of the defence-related genes CHS,GST, PAL and PR-1. This induction was suppressed by inhibitors of calcium flux or NADPH oxidase, indicating that increases in both cytosolic calcium and H2O2 are required for OGA-induced gene expression.

  6. Regulation of the New Arabidopsis Imprinted Gene AtBMI1C Requires the Interplay of Different Epigenetic Mechanisms

    Institute of Scientific and Technical Information of China (English)

    Fabian Bratzel; ChaoYang; Alexandra Ancelova; Gema López-Torrejón; Marcus Koch; Juan Carlos del Pozo; Myriam Calonje

    2012-01-01

    Recently,it has been shown that plants contain homologs to the animal Polycomb repressive complex 1 (PRC1)components BMI1 and RING1A/B.In Arabidopsis,there are three BMI1-like genes,two of which,AtBMI1A and B,are required during post-embryonic plant growth to repress embryonic traits and allow cell differentiation.However,little is known about the third BMI1-like gene,AtBMI1C.In this work,we show that AtBMI1C is only expressed during endosperm and stamen development.AtBMI1C is an imprinted gene expressed from the maternal allele in the endosperm but biallelically expressed in stamen.We found that the characteristic expression pattern of AtBMI1C is the result of a complex epigenetic regulation that involves CG DNA methylation,RNA-directed non-CG DNA methylation (RdDM),and PcG activity.Our results show the orchestrated interplay of different epigenetic mechanisms in regulating gene expression throughout development,shedding light on the current hypotheses for the origin and mechanism of imprinting in plant endosperm.

  7. Ku is required for telomeric C-rich strand maintenance but not for end-to-end chromosome fusions in Arabidopsis

    OpenAIRE

    Riha, Karel; Dorothy E Shippen

    2003-01-01

    Telomere dysfunction arising from mutations in telomerase or in telomere capping proteins leads to end-to-end chromosome fusions. Paradoxically, the Ku70/80 heterodimer, essential for nonhomologous end-joining double-strand break repair, is also found at telomeres, and in mammals it is required to prevent telomere fusion. Previously, we showed that inactivation of Ku70 in Arabidopsis results in telomere lengthening. Here, we have demonstrated that this telomere elongation is telomerase depend...

  8. A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

    OpenAIRE

    Levin, J Z; Fletcher, J C; Chen, X.; Meyerowitz, E M

    1998-01-01

    In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting b...

  9. Mutational definition of binding requirements of an hnRNP-like protein in Arabidopsis using fluorescence correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Leder, Verena [Molecular Cell Physiology, Faculty of Biology, Bielefeld University (Germany); Biomolecular Photonics, Faculty of Physics, Bielefeld University (Germany); Lummer, Martina [Molecular Cell Physiology, Faculty of Biology, Bielefeld University (Germany); Tegeler, Kathrin [Molecular Cell Physiology, Faculty of Biology, Bielefeld University (Germany); Biomolecular Photonics, Faculty of Physics, Bielefeld University (Germany); Humpert, Fabian [Biomolecular Photonics, Faculty of Physics, Bielefeld University (Germany); Lewinski, Martin [Molecular Cell Physiology, Faculty of Biology, Bielefeld University (Germany); Schüttpelz, Mark [Biomolecular Photonics, Faculty of Physics, Bielefeld University (Germany); Staiger, Dorothee, E-mail: dorothee.staiger@uni-bielefeld.de [Molecular Cell Physiology, Faculty of Biology, Bielefeld University (Germany)

    2014-10-10

    Highlights: • We use FCS to investigate binding site requirements for the hnRNP-like protein AtGRP7. • We identify three nucleotides critical for AtGRP7 binding to its own intron. • Mutation of the conserved R{sup 49} abolishes binding altogether. • The paralogue AtGRP8 binds to an overlapping motif with different sequence requirement. • The glycine-rich stretch of a plant hnRNP-like protein contributes to binding. - Abstract: Arabidopsis thaliana glycine-rich RNA binding protein 7 (AtGRP7) is part of a negative feedback loop through which it regulates alternative splicing and steady-state abundance of its pre-mRNA. Here we use fluorescence correlation spectroscopy to investigate the requirements for AtGRP7 binding to its intron using fluorescently-labelled synthetic oligonucleotides. By systematically introducing point mutations we identify three nucleotides that lead to an increased K{sub d} value when mutated and thus are critical for AtGRP7 binding. Simultaneous mutation of all three residues abrogates binding. The paralogue AtGRP8 binds to an overlapping motif but with a different sequence preference, in line with overlapping but not identical functions of this protein pair. Truncation of the glycine-rich domain reduces the binding affinity of AtGRP7, showing for the first time that the glycine-rich stretch of a plant hnRNP-like protein contributes to binding. Mutation of the conserved R{sup 49} that is crucial for AtGRP7 function in pathogen defence and splicing abolishes binding.

  10. Mutational definition of binding requirements of an hnRNP-like protein in Arabidopsis using fluorescence correlation spectroscopy

    International Nuclear Information System (INIS)

    Highlights: • We use FCS to investigate binding site requirements for the hnRNP-like protein AtGRP7. • We identify three nucleotides critical for AtGRP7 binding to its own intron. • Mutation of the conserved R49 abolishes binding altogether. • The paralogue AtGRP8 binds to an overlapping motif with different sequence requirement. • The glycine-rich stretch of a plant hnRNP-like protein contributes to binding. - Abstract: Arabidopsis thaliana glycine-rich RNA binding protein 7 (AtGRP7) is part of a negative feedback loop through which it regulates alternative splicing and steady-state abundance of its pre-mRNA. Here we use fluorescence correlation spectroscopy to investigate the requirements for AtGRP7 binding to its intron using fluorescently-labelled synthetic oligonucleotides. By systematically introducing point mutations we identify three nucleotides that lead to an increased Kd value when mutated and thus are critical for AtGRP7 binding. Simultaneous mutation of all three residues abrogates binding. The paralogue AtGRP8 binds to an overlapping motif but with a different sequence preference, in line with overlapping but not identical functions of this protein pair. Truncation of the glycine-rich domain reduces the binding affinity of AtGRP7, showing for the first time that the glycine-rich stretch of a plant hnRNP-like protein contributes to binding. Mutation of the conserved R49 that is crucial for AtGRP7 function in pathogen defence and splicing abolishes binding

  11. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    NARCIS (Netherlands)

    Zwiewka, M.; Feraru, E.; Moller, B.K.; Hwang, I.; Feraru, M.I.; Kleine-Vehn, J.; Weijers, D.; Friml, J.

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells. It involves regulation of cargo sorting, vesicle formation, trafficking and fusion processes at multiple levels. Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals

  12. The WIGGUM gene is required for proper regulation of floral meristem size in Arabidopsis

    OpenAIRE

    Running, Mark P; Fletcher, Jennifer C; Meyerowitz, Elliot M.

    1998-01-01

    The study of cell division control within developing tissues is central to understanding the processes of pattern formation. The floral meristem of angiosperms gives rise to floral organs in a particular number and pattern. Despite its critical role, little is known about how cell division is controlled in the floral meristem, and few genes involved have been identified. We describe the phenotypic effects of mutations in WIGGUM, a gene required for control of cell proliferation in the floral ...

  13. Plastid chaperonin proteins Cpn60α and Cpn60β are required for plastid division in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Osteryoung Katherine W

    2009-04-01

    Full Text Available Abstract Background Plastids arose from a free-living cyanobacterial endosymbiont and multiply by binary division as do cyanobacteria. Plastid division involves nucleus-encoded homologs of cyanobacterial division proteins such as FtsZ, MinD, MinE, and ARC6. However, homologs of many other cyanobacterial division genes are missing in plant genomes and proteins of host eukaryotic origin, such as a dynamin-related protein, PDV1 and PDV2 are involved in the division process. Recent identification of plastid division proteins has started to elucidate the similarities and differences between plastid division and cyanobacterial cell division. To further identify new proteins that are required for plastid division, we characterized previously and newly isolated plastid division mutants of Arabidopsis thaliana. Results Leaf cells of two mutants, br04 and arc2, contain fewer, larger chloroplasts than those of wild type. We found that ARC2 and BR04 are identical to nuclear genes encoding the plastid chaperonin 60α (ptCpn60α and chaperonin 60β (ptCpn60β proteins, respectively. In both mutants, plastid division FtsZ ring formation was partially perturbed though the level of FtsZ2-1 protein in plastids of ptcpn60β mutants was similar to that in wild type. Phylogenetic analyses showed that both ptCpn60 proteins are derived from ancestral cyanobacterial proteins. The A. thaliana genome encodes two members of ptCpn60α family and four members of ptCpn60β family respectively. We found that a null mutation in ptCpn60α abolished greening of plastids and resulted in an albino phenotype while a weaker mutation impairs plastid division and reduced chlorophyll levels. The functions of at least two ptCpn60β proteins are redundant and the appearance of chloroplast division defects is dependent on the number of mutant alleles. Conclusion Our results suggest that both ptCpn60α and ptCpn60β are required for the formation of a normal plastid division apparatus, as

  14. Shade avoidance 6 encodes an Arabidopsis flap endonuclease required for maintenance of genome integrity and development.

    Science.gov (United States)

    Zhang, Yijuan; Wen, Chunhong; Liu, Songbai; Zheng, Li; Shen, Binghui; Tao, Yi

    2016-02-18

    Flap endonuclease-1 (FEN1) belongs to the Rad2 family of structure-specific nucleases. It is required for several DNA metabolic pathways, including DNA replication and DNA damage repair. Here, we have identified a shade avoidance mutant, sav6, which reduces the mRNA splicing efficiency of SAV6. We have demonstrated that SAV6 is an FEN1 homologue that shows double-flap endonuclease and gap-dependent endonuclease activity, but lacks exonuclease activity. sav6 mutants are hypersensitive to DNA damage induced by ultraviolet (UV)-C radiation and reagents that induce double-stranded DNA breaks, but exhibit normal responses to chemicals that block DNA replication. Signalling components that respond to DNA damage are constitutively activated in sav6 mutants. These data indicate that SAV6 is required for DNA damage repair and the maintenance of genome integrity. Mutant sav6 plants also show reduced root apical meristem (RAM) size and defective quiescent centre (QC) development. The expression of SMR7, a cell cycle regulatory gene, and ERF115 and PSK5, regulators of QC division, is increased in sav6 mutants. Their constitutive induction is likely due to the elevated DNA damage responses in sav6 and may lead to defects in the development of the RAM and QC. Therefore, SAV6 assures proper root development through maintenance of genome integrity. PMID:26721386

  15. SPATULA and ALCATRAZ, are partially redundant, functionally diverging bHLH genes required for Arabidopsis gynoecium and fruit development.

    Science.gov (United States)

    Groszmann, Michael; Paicu, Teodora; Alvarez, John P; Swain, Steve M; Smyth, David R

    2011-12-01

    The Arabidopsis gynoecium is a complex organ that facilitates fertilization, later developing into a dehiscent silique that protects seeds until their dispersal. Identifying genes important for development is often hampered by functional redundancy. We report unequal redundancy between two closely related genes, SPATULA (SPT) and ALCATRAZ (ALC), revealing previously unknown developmental roles for each. SPT is known to support septum, style and stigma development in the flower, whereas ALC is involved in dehiscence zone development in the fruit. ALC diverged from a SPT-like ancestor following gene duplication coinciding with the At-β polyploidy event. Here we show that ALC is also involved in early gynoecium development, and SPT in later valve margin generation in the silique. Evidence includes the increased severity of early gynoecium disruption, and of later valve margin defects, in spt-alc double mutants. In addition, a repressive version of SPT (35S:SPT-SRDX) disrupts both structures. Consistent with redundancy, ALC and SPT expression patterns overlap in these tissues, and the ALC promoter carries two atypical E-box elements identical to one in SPT required for valve margin expression. Further, SPT can heterodimerize with ALC, and 35S:SPT can fully complement dehiscence defects in alc mutants, although 35S:ALC can only partly complement spt gynoecium disruptions, perhaps associated with its sequence simplification. Interactions with FRUITFULL and SHATTERPROOF genes differ somewhat between SPT and ALC, reflecting their different specializations. These two genes are apparently undergoing subfunctionalization, with SPT essential for earlier carpel margin tissues, and ALC specializing in later dehiscence zone development. PMID:21801252

  16. Of the Nine Cytidine Deaminase-Like Genes in Arabidopsis, Eight Are Pseudogenes and Only One Is Required to Maintain Pyrimidine Homeostasis in Vivo.

    Science.gov (United States)

    Chen, Mingjia; Herde, Marco; Witte, Claus-Peter

    2016-06-01

    CYTIDINE DEAMINASE (CDA) catalyzes the deamination of cytidine to uridine and ammonia in the catabolic route of C nucleotides. The Arabidopsis (Arabidopsis thaliana) CDA gene family comprises nine members, one of which (AtCDA) was shown previously in vitro to encode an active CDA. A possible role in C-to-U RNA editing or in antiviral defense has been discussed for other members. A comprehensive bioinformatic analysis of plant CDA sequences, combined with biochemical functionality tests, strongly suggests that all Arabidopsis CDA family members except AtCDA are pseudogenes and that most plants only require a single CDA gene. Soybean (Glycine max) possesses three CDA genes, but only two encode functional enzymes and just one has very high catalytic efficiency. AtCDA and soybean CDAs are located in the cytosol. The functionality of AtCDA in vivo was demonstrated with loss-of-function mutants accumulating high amounts of cytidine but also CMP, cytosine, and some uridine in seeds. Cytidine hydrolysis in cda mutants is likely caused by NUCLEOSIDE HYDROLASE1 (NSH1) because cytosine accumulation is strongly reduced in a cda nsh1 double mutant. Altered responses of the cda mutants to fluorocytidine and fluorouridine indicate that a dual specific nucleoside kinase is involved in cytidine as well as uridine salvage. CDA mutants display a reduction in rosette size and have fewer leaves compared with the wild type, which is probably not caused by defective pyrimidine catabolism but by the accumulation of pyrimidine catabolism intermediates reaching toxic concentrations. PMID:27208239

  17. A new role for an old enzyme: Nitrate reductase-mediated nitric oxide generation is required for abscisic acid-induced stomatal closure in Arabidopsis thaliana

    Science.gov (United States)

    Desikan, Radhika; Griffiths, Rachael; Hancock, John; Neill, Steven

    2002-01-01

    The plant hormone abscisic acid (ABA), synthesized in response to water-deficit stress, induces stomatal closure via activation of complex signaling cascades. Recent work has established that nitric oxide (NO) is a key signaling molecule mediating ABA-induced stomatal closure. However, the biosynthetic origin of NO in guard cells has not yet been resolved. Here, we provide pharmacological, physiological, and genetic evidence that NO synthesis in Arabidopsis guard cells is mediated by the enzyme nitrate reductase (NR). Guard cells of wild-type Arabidopsis generate NO in response to treatment with ABA and nitrite, a substrate for NR. Moreover, NR-mediated NO synthesis is required for ABA-induced stomatal closure. However, in the NR double mutant, nia1, nia2 that has diminished NR activity, guard cells do not synthesize NO nor do the stomata close in response to ABA or nitrite, although stomatal opening is still inhibited by ABA. Furthermore, by using the ABA-insensitive (ABI) abi1–1 and abi2–1 mutants, we show that the ABI1 and ABI2 protein phosphatases are downstream of NO in the ABA signal-transduction cascade. These data demonstrate a previously uncharacterized signaling role for NR, that of mediating ABA-induced NO synthesis in Arabidopsis guard cells. PMID:12446847

  18. Requirement of the C3HC4 zinc RING finger of the Arabidopsis PEX10 for photorespiration and leaf peroxisome contact with chloroplasts

    OpenAIRE

    Schumann, Uwe; Prestele, Jakob; O'Geen, Henriette; Brueggeman, Robert; Wanner, Gerhard; Gietl, Christine

    2007-01-01

    Plant peroxisomes perform multiple vital metabolic processes including lipid mobilization in oil-storing seeds, photorespiration, and hormone biosynthesis. Peroxisome biogenesis requires the function of peroxin (PEX) proteins, including PEX10, a C3HC4 Zn RING finger peroxisomal membrane protein. Loss of function of PEX10 causes embryo lethality at the heart stage. We investigated the function of PEX10 with conditional sublethal mutants. Four T-DNA insertion lines expressing pex10 with a dysfu...

  19. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Maria Zwiewka; Elena Feraru; Barbara M(o)ller; Inhwan Hwang; Mugurel I Feraru; Jürgen Kleine-Vehn; Dolf Weijers; Ji(n) Friml

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells.It involves regulation of cargo sorting,vesicle formation,trafficking and fusion processes at multiple levels.Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals but their existence and function in plants have not been demonstrated.Here we report the identification of the protein-affected trafficking 4 (pat4) mutant defective in the putative δ subunit of the AP-3 complex.pat4 and pat2,a mutant isolated from the same GFP imaging-based forward genetic screen that lacks a functional putative AP-3 β,as well as dominant negative AP-3 μ transgenic lines display undistinguishable phenotypes characterized by largely normal morphology and development,but strong intracellular accumulation of membrane proteins in aberrant vacuolar structures.All mutants are defective in morphology and function of lytic and protein storage vacuoles (PSVs) but show normal sorting of reserve proteins to PSVs.Immunoprecipitation experiments and genetic studies revealed tight functional and physical associations of putative AP-3 β and AP-3 δ subunits.Furthermore,both proteins are closely linked with putative AP-3 μ and σ subunits and several components of the clathrin and dynamin machineries.Taken together,these results demonstrate that AP complexes,similar to those in other eukaryotes,exist in plants,and that AP-3 plays a specific role in the regulation of biogenesis and function of vacuoles in plant cells.

  20. The Arabidopsis ISR1 locus is required for rhizobacteria-mediated induced systemic resistance against different pathogens

    NARCIS (Netherlands)

    Ton, J.; Pelt, J.A. van; Loon, L.C. van; Pieterse, C.M.J.

    2002-01-01

    In Arabidopsis thaliana, non-pathogenic, root-colonizing Pseudomonas fluorescens WCS417r bacteria trigger an induced systemic resistance (ISR) that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). In contrast to SAR, WCS417r-mediated ISR is controlled by a salicylic

  1. Stem cell organization in Arabidopsis

    OpenAIRE

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or meristems stay active throughout plant-life. Specification of stem cells occurs very early during development of the emrbyo and they are maintained during later stages. The Arabidopsis embryo is a hig...

  2. A Specialized Histone H1 Variant Is Required for Adaptive Responses to Complex Abiotic Stress and Related DNA Methylation in Arabidopsis.

    Science.gov (United States)

    Rutowicz, Kinga; Puzio, Marcin; Halibart-Puzio, Joanna; Lirski, Maciej; Kotliński, Maciej; Kroteń, Magdalena A; Knizewski, Lukasz; Lange, Bartosz; Muszewska, Anna; Śniegowska-Świerk, Katarzyna; Kościelniak, Janusz; Iwanicka-Nowicka, Roksana; Buza, Krisztián; Janowiak, Franciszek; Żmuda, Katarzyna; Jõesaar, Indrek; Laskowska-Kaszub, Katarzyna; Fogtman, Anna; Kollist, Hannes; Zielenkiewicz, Piotr; Tiuryn, Jerzy; Siedlecki, Paweł; Swiezewski, Szymon; Ginalski, Krzysztof; Koblowska, Marta; Archacki, Rafał; Wilczynski, Bartek; Rapacz, Marcin; Jerzmanowski, Andrzej

    2015-11-01

    Linker (H1) histones play critical roles in chromatin compaction in higher eukaryotes. They are also the most variable of the histones, with numerous nonallelic variants cooccurring in the same cell. Plants contain a distinct subclass of minor H1 variants that are induced by drought and abscisic acid and have been implicated in mediating adaptive responses to stress. However, how these variants facilitate adaptation remains poorly understood. Here, we show that the single Arabidopsis (Arabidopsis thaliana) stress-inducible variant H1.3 occurs in plants in two separate and most likely autonomous pools: a constitutive guard cell-specific pool and a facultative environmentally controlled pool localized in other tissues. Physiological and transcriptomic analyses of h1.3 null mutants demonstrate that H1.3 is required for both proper stomatal functioning under normal growth conditions and adaptive developmental responses to combined light and water deficiency. Using fluorescence recovery after photobleaching analysis, we show that H1.3 has superfast chromatin dynamics, and in contrast to the main Arabidopsis H1 variants H1.1 and H1.2, it has no stable bound fraction. The results of global occupancy studies demonstrate that, while H1.3 has the same overall binding properties as the main H1 variants, including predominant heterochromatin localization, it differs from them in its preferences for chromatin regions with epigenetic signatures of active and repressed transcription. We also show that H1.3 is required for a substantial part of DNA methylation associated with environmental stress, suggesting that the likely mechanism underlying H1.3 function may be the facilitation of chromatin accessibility by direct competition with the main H1 variants. PMID:26351307

  3. A Specialized Histone H1 Variant Is Required for Adaptive Responses to Complex Abiotic Stress and Related DNA Methylation in Arabidopsis1[OPEN

    Science.gov (United States)

    Rutowicz, Kinga; Puzio, Marcin; Halibart-Puzio, Joanna; Lirski, Maciej; Kotliński, Maciej; Kroteń, Magdalena A.; Knizewski, Lukasz; Lange, Bartosz; Muszewska, Anna; Śniegowska-Świerk, Katarzyna; Kościelniak, Janusz; Iwanicka-Nowicka, Roksana; Buza, Krisztián; Janowiak, Franciszek; Żmuda, Katarzyna; Jõesaar, Indrek; Laskowska-Kaszub, Katarzyna; Fogtman, Anna; Kollist, Hannes; Zielenkiewicz, Piotr; Tiuryn, Jerzy; Siedlecki, Paweł; Swiezewski, Szymon; Ginalski, Krzysztof; Koblowska, Marta; Archacki, Rafał; Wilczynski, Bartek; Rapacz, Marcin; Jerzmanowski, Andrzej

    2015-01-01

    Linker (H1) histones play critical roles in chromatin compaction in higher eukaryotes. They are also the most variable of the histones, with numerous nonallelic variants cooccurring in the same cell. Plants contain a distinct subclass of minor H1 variants that are induced by drought and abscisic acid and have been implicated in mediating adaptive responses to stress. However, how these variants facilitate adaptation remains poorly understood. Here, we show that the single Arabidopsis (Arabidopsis thaliana) stress-inducible variant H1.3 occurs in plants in two separate and most likely autonomous pools: a constitutive guard cell-specific pool and a facultative environmentally controlled pool localized in other tissues. Physiological and transcriptomic analyses of h1.3 null mutants demonstrate that H1.3 is required for both proper stomatal functioning under normal growth conditions and adaptive developmental responses to combined light and water deficiency. Using fluorescence recovery after photobleaching analysis, we show that H1.3 has superfast chromatin dynamics, and in contrast to the main Arabidopsis H1 variants H1.1 and H1.2, it has no stable bound fraction. The results of global occupancy studies demonstrate that, while H1.3 has the same overall binding properties as the main H1 variants, including predominant heterochromatin localization, it differs from them in its preferences for chromatin regions with epigenetic signatures of active and repressed transcription. We also show that H1.3 is required for a substantial part of DNA methylation associated with environmental stress, suggesting that the likely mechanism underlying H1.3 function may be the facilitation of chromatin accessibility by direct competition with the main H1 variants. PMID:26351307

  4. Transgenerational adaptation of Arabidopsis to stress requires DNA methylation and the function of Dicer-like proteins.

    Directory of Open Access Journals (Sweden)

    Alex Boyko

    Full Text Available Epigenetic states and certain environmental responses in mammals and seed plants can persist in the next sexual generation. These transgenerational effects have potential adaptative significance as well as medical and agronomic ramifications. Recent evidence suggests that some abiotic and biotic stress responses of plants are transgenerational. For example, viral infection of tobacco plants and exposure of Arabidopsis thaliana plants to UVC and flagellin can induce transgenerational increases in homologous recombination frequency (HRF. Here we show that exposure of Arabidopsis plants to stresses, including salt, UVC, cold, heat and flood, resulted in a higher HRF, increased global genome methylation, and higher tolerance to stress in the untreated progeny. This transgenerational effect did not, however, persist in successive generations. Treatment of the progeny of stressed plants with 5-azacytidine was shown to decrease global genomic methylation and enhance stress tolerance. Dicer-like (DCL 2 and DCL3 encode Dicer activities important for small RNA-dependent gene silencing. Stress-induced HRF and DNA methylation were impaired in dcl2 and dcl3 deficiency mutants, while in dcl2 mutants, only stress-induced stress tolerance was impaired. Our results are consistent with the hypothesis that stress-induced transgenerational responses in Arabidopsis depend on altered DNA methylation and smRNA silencing pathways.

  5. Who abandons embryos after IVF?

    LENUS (Irish Health Repository)

    Walsh, A P H

    2010-04-01

    This investigation describes features of in vitro fertilisation (IVF) patients who never returned to claim their embryos following cryopreservation. Frozen embryo data were reviewed to establish communication patterns between patient and clinic; embryos were considered abandoned when 1) an IVF patient with frozen embryo\\/s stored at our facility failed to make contact with our clinic for > 2 yrs and 2) the patient could not be located after a multi-modal outreach effort was undertaken. For these patients, telephone numbers had been disconnected and no forwarding address was available. Patient, spouse and emergency family contact\\/s all escaped detection efforts despite an exhaustive public database search including death records and Internet directory portals. From 3244 IVF cycles completed from 2000 to 2008, > or = 1 embryo was frozen in 1159 cases (35.7%). Those without correspondence for > 2 yrs accounted for 292 (25.2%) patients with frozen embryos; 281 were contacted by methods including registered (signature involving abandoned embryos did not differ substantially from other patients. The goal of having a baby was achieved by 10\\/11 patients either by spontaneous conception, adoption or IVF. One patient moved away with conception status unconfirmed. The overall rate of embryo abandonment was 11\\/1159 (< 1%) in this IVF population. Pre-IVF counselling minimises, but does not totally eliminate, the problem of abandoned embryos. As the number of abandoned embryos from IVF accumulates, their fate urgently requires clarification. We propose that clinicians develop a policy consistent with relevant Irish Constitutional provisions to address this medical dilemma.

  6. MCM8 is required for a pathway of meiotic double-strand break repair independent of DMC1 in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Wayne Crismani

    Full Text Available Mini-chromosome maintenance (MCM 2-9 proteins are related helicases. The first six, MCM2-7, are essential for DNA replication in all eukaryotes. In contrast, MCM8 is not always conserved in eukaryotes but is present in Arabidopsis thaliana. MCM8 is required for 95% of meiotic crossovers (COs in Drosophila and is essential for meiosis completion in mouse, prompting us to study this gene in Arabidopsis meiosis. Three allelic Atmcm8 mutants showed a limited level of chromosome fragmentation at meiosis. This defect was dependent on programmed meiotic double-strand break (DSB formation, revealing a role for AtMCM8 in meiotic DSB repair. In contrast, CO formation was not affected, as shown both genetically and cytologically. The Atmcm8 DSB repair defect was greatly amplified in the absence of the DMC1 recombinase or in mutants affected in DMC1 dynamics (sds, asy1. The Atmcm8 fragmentation defect was also amplified in plants heterozygous for a mutation in either recombinase, DMC1 or RAD51. Finally, in the context of absence of homologous chromosomes (i.e. haploid, mutation of AtMCM8 also provoked a low level of chromosome fragmentation. This fragmentation was amplified by the absence of DMC1 showing that both MCM8 and DMC1 can promote repair on the sister chromatid in Arabidopsis haploids. Altogether, this establishes a role for AtMCM8 in meiotic DSB repair, in parallel to DMC1. We propose that MCM8 is involved with RAD51 in a backup pathway that repairs meiotic DSB without giving CO when the major pathway, which relies on DMC1, fails.

  7. SDG2-Mediated H3K4 Methylation Is Required for Proper Arabidopsis Root Growth and Development

    OpenAIRE

    Xiaozhen Yao; Haiyang Feng; Yu Yu; Aiwu Dong; Wen-Hui Shen

    2013-01-01

    Trithorax group (TrxG) proteins are evolutionarily conserved in eukaryotes and play critical roles in transcriptional activation via deposition of histone H3 lysine 4 trimethylation (H3K4me3) in chromatin. Several Arabidopsis TrxG members have been characterized, and among them SET DOMAIN GROUP 2 (SDG2) has been shown to be necessary for global genome-wide H3K4me3 deposition. Although pleiotropic phenotypes have been uncovered in the sdg2 mutants, SDG2 function in the regulation of stem cell ...

  8. The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Liu, Dong; Li, Weichun; Cheng, Jianfeng

    2016-01-01

    Chloroplast biogenesis is one of the most important subjects in plant biology. In this study, an Arabidopsis early chloroplast biogenesis mutant with a delayed pale-greening phenotype (dpg1) was isolated from a T-DNA insertion mutant collection. Both cotyledons and true leaves of dpg1 mutants were initially albino but gradually became pale green as the plant matured. Transmission electron microscopic observations revealed that the mutant displayed a delayed proplastid-to-chloroplast transition. Sequence and transcription analyses showed that AtDPG1 encodes a putatively chloroplast-localized protein containing three predicted transmembrane helices and that its expression depends on both light and developmental status. GUS staining for AtDPG1::GUS transgenic lines showed that this gene was widely expressed throughout the plant and that higher expression levels were predominantly found in green tissues during the early stages of Arabidopsis seedling development. Furthermore, quantitative real-time RT-PCR analyses revealed that a number of chloroplast- and nuclear-encoded genes involved in chlorophyll biosynthesis, photosynthesis and chloroplast development were substantially down-regulated in the dpg1 mutant. These data indicate that AtDPG1 plays an essential role in early chloroplast biogenesis, and its absence triggers chloroplast-to-nucleus retrograde signalling, which ultimately down-regulates the expression of nuclear genes encoding chloroplast-localized proteins. PMID:27160321

  9. Nucleolin is required for DNA methylation state and the expression of rRNA gene variants in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Frédéric Pontvianne

    2010-11-01

    Full Text Available In eukaryotes, 45S rRNA genes are arranged in tandem arrays in copy numbers ranging from several hundred to several thousand in plants. Although it is clear that not all copies are transcribed under normal growth conditions, the molecular basis controlling the expression of specific sets of rRNA genes remains unclear. Here, we report four major rRNA gene variants in Arabidopsis thaliana. Interestingly, while transcription of one of these rRNA variants is induced, the others are either repressed or remain unaltered in A. thaliana plants with a disrupted nucleolin-like protein gene (Atnuc-L1. Remarkably, the most highly represented rRNA gene variant, which is inactive in WT plants, is reactivated in Atnuc-L1 mutants. We show that accumulated pre-rRNAs originate from RNA Pol I transcription and are processed accurately. Moreover, we show that disruption of the AtNUC-L1 gene induces loss of symmetrical DNA methylation without affecting histone epigenetic marks at rRNA genes. Collectively, these data reveal a novel mechanism for rRNA gene transcriptional regulation in which the nucleolin protein plays a major role in controlling active and repressed rRNA gene variants in Arabidopsis.

  10. Expectant Fathers, Abortion, and Embryos.

    Science.gov (United States)

    Purvis, Dara E

    2015-01-01

    One thread of abortion criticism, arguing that gender equality requires that men be allowed to terminate legal parental status and obligations, has reinforced the stereotype of men as uninterested in fatherhood. As courts facing disputes over stored pre-embryos weigh the equities of allowing implantation of the pre-embryos, this same gender stereotype has been increasingly incorporated into a legal balancing test, leading to troubling implications for ART and family law. PMID:26242955

  11. Radioactive labeling of proteins in cultured postimplantation mouse embryos. I. Influence of the embryo preparation method

    International Nuclear Information System (INIS)

    Conditions for optimum incorporation of radioactive amino acids into proteins of cultured postimplantation mouse embryos were investigated under the aspect of using these proteins for two-dimensional electrophoretic separations followed by fluorography. The aim was to obtain highly radioactive proteins under conditions as physiological as possible. Embryos at Days 10, 11, and 12 of gestation were prepared in different ways and incubated for 4 h in Tyrode's solution containing [3H]amino acids (mixture) at a concentration of 27 microCi/ml medium. The preparations were: (a) yolk sac opened, placenta and blood circulation intact; (b) yolk sac and amnion opened, placenta and blood circulation intact (Day 10 embryos only); (c) placenta, yolk sac, and amnion removed (embryo naked); (d) naked embryos cut randomly into pieces (Day 10 embryos only). After incubation whole embryos or certain parts (tail, liver, rest body) were investigated by determining the radioactivity taken up by the protein. The results are given in dpm per mg protein per embryo. Radioactivity of proteins was about 3 times higher in naked embryos than in embryos left in their yolk sacs. This was true for all three stages investigated. However, the degree of radioactivity in the various parts of naked embryos differed by a factor of 15, whereas radioactivity was evenly distributed in embryos incubated in their yolk sacs. Therefore, embryos prepared according to the first method (see above) fulfilled the conditions required at the best

  12. The role of the GA signaling SLY1 in Arabidopsis seed germination

    Science.gov (United States)

    Seed dormancy, afterripening, and germination are complex developmental process regulated by phytohormones. The phytohormone abscisic acid (ABA) is needed to set up seed dormancy during embryo maturation whereas gibberellin (GA) stimulates seed germination. In tomato and Arabidopsis, GA is clearly ...

  13. TOM1, an Arabidopsis gene required for efficient multiplication of a tobamovirus, encodes a putative transmembrane protein.

    Science.gov (United States)

    Yamanaka, T; Ohta, T; Takahashi, M; Meshi, T; Schmidt, R; Dean, C; Naito, S; Ishikawa, M

    2000-08-29

    Host-encoded factors play an important role in virus multiplication, acting in concert with virus-encoded factors. However, information regarding the host factors involved in this process is limited. Here we report the map-based cloning of an Arabidopsis thaliana gene, TOM1, which is necessary for the efficient multiplication of tobamoviruses, positive-strand RNA viruses infecting a wide variety of plants. The TOM1 mRNA is suggested to encode a 291-aa polypeptide that is predicted to be a multipass transmembrane protein. The Sos recruitment assay supported the hypothesis that TOM1 is associated with membranes, and in addition, that TOM1 interacts with the helicase domain of tobamovirus-encoded replication proteins. Taken into account that the tobamovirus replication complex is associated with membranes, we propose that TOM1 participates in the in vivo formation of the replication complex by serving as a membrane anchor. PMID:10944200

  14. Arabidopsis VARIEGATED 3 encodes a chloroplast-targeted, zinc-finger protein required for chloroplast and palisade cell development

    DEFF Research Database (Denmark)

    Næsted, Henrik; Holm, Agnethe; Jenkins, Tom; Nielsen, Henrik Bjørn; Harris, Cassandra A.; Beale, Michael H.; Andersen, Mathias; Mant, Alexandra; Scheller, Henrik Vibe; Camara, Bilal; Mattsson, Ole; Mundy, John

    2004-01-01

    The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 pro...... pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development....... protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that...

  15. The HopQ1 effector's nucleoside hydrolase-like domain is required for bacterial virulence in arabidopsis and tomato, but not host recognition in tobacco.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Bacterial pathogens deliver multiple effector proteins into host cells to facilitate bacterial growth. HopQ1 is an effector from Pseudomonas syringae pv. tomato DC3000 that is conserved across multiple bacterial pathogens which infect plants. HopQ1's central region possesses some homology to nucleoside hydrolases, but possesses an alternative aspartate motif not found in characterized enzymes. A structural model was generated for HopQ1 based on the E. coli RihB nucleoside hydrolase and the role of HopQ1's potential catalytic residues for promoting bacterial virulence and recognition in Nicotiana tabacum was investigated. Transgenic Arabidopsis plants expressing HopQ1 exhibit enhanced disease susceptibility to DC3000. HopQ1 can also promote bacterial virulence on tomato when naturally delivered from DC3000. HopQ1's nucleoside hydrolase-like domain alone is sufficient to promote bacterial virulence, and putative catalytic residues are required for virulence promotion during bacterial infection of tomato and in transgenic Arabidopsis lines. HopQ1 is recognized and elicits cell death when transiently expressed in N. tabacum. Residues required to promote bacterial virulence were dispensable for HopQ1's cell death promoting activities in N. tabacum. Although HopQ1 has some homology to nucleoside hydrolases, we were unable to detect HopQ1 enzymatic activity or nucleoside binding capability using standard substrates. Thus, it is likely that HopQ1 promotes pathogen virulence by hydrolyzing alternative ribose-containing substrates in planta.

  16. The eggshell is required for meiotic fidelity, polar-body extrusion and polarization of the C. elegans embryo

    Directory of Open Access Journals (Sweden)

    Dennis James W

    2006-10-01

    Full Text Available Abstract Background Fertilization restores the diploid state and begins the process by which the single-cell oocyte is converted into a polarized, multicellular organism. In the nematode, Caenorhabditis elegans, two of the earliest events following fertilization are secretion of the chitinous eggshell and completion of meiosis, and in this report we demonstrate that the eggshell is essential for multiple developmental events at the one-cell stage. Results We show that the GLD (Germline differentiation abnormal-1-regulated hexosamine pathway enzyme, glucosamine-6-phosphate N-acetyltransferase (GNA-2, is required for synthesis of uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc, the substrate for eggshell chitin synthesis by chitin synthase-1 (CHS-1. Furthermore, while chs-1(RNAi or combined RNAi with the chitin-binding proteins, CEJ-1 and B0280.5, does not interfere with normal meiotic timing, lagging chromosomes are observed at meiosis, and polar-body extrusion fails. We also demonstrate that chitin, and either CEJ-1 or B0280.5, are essential for the osmotic/permeability barrier and for movement of the sperm pronucleus/centrosome complex to the cortex, which is associated with the initiation of polarization. Conclusion Our results indicate that the eggshell is required in single-cell C. elegans development, playing an essential role in multiple actin-dependent early events. Furthermore, the earliest meiotic roles precede osmotic barrier formation, indicating that the role of the eggshell is not limited to generation of the osmotic barrier.

  17. The protease degrading sperm histones post-fertilization in sea urchin eggs is a nuclear cathepsin L that is further required for embryo development.

    Directory of Open Access Journals (Sweden)

    Violeta Morin

    Full Text Available Proteolysis of sperm histones in the sea urchin male pronucleus is the consequence of the activation at fertilization of a maternal cysteine protease. We previously showed that this protein is required for male chromatin remodelling and for cell-cycle progression in the newly formed embryos. This enzyme is present in the nucleus of unfertilized eggs and is rapidly recruited to the male pronucleus after insemination. Interestingly, this cysteine-protease remains co-localized with chromatin during S phase of the first cell cycle, migrates to the mitotic spindle in M-phase and is re-located to the nuclei of daughter cells after cytokinesis. Here we identified the protease encoding cDNA and found a high sequence identity to cathepsin proteases of various organisms. A phylogenetical analysis clearly demonstrates that this sperm histone protease (SpHp belongs to the cathepsin L sub-type. After an initial phase of ubiquitous expression throughout cleavage stages, SpHp gene transcripts become restricted to endomesodermic territories during the blastula stage. The transcripts are localized in the invaginating endoderm during gastrulation and a gut specific pattern continues through the prism and early pluteus stages. In addition, a concomitant expression of SpHp transcripts is detected in cells of the skeletogenic lineage and in accordance a pharmacological disruption of SpHp activity prevents growth of skeletal rods. These results further document the role of this nuclear cathepsin L during development.

  18. The extracellular matrix protein artichoke is required for integrity of ciliated mechanosensory and chemosensory organs in Drosophila embryos.

    Science.gov (United States)

    Andrés, Marta; Turiégano, Enrique; Göpfert, Martin C; Canal, Inmaculada; Torroja, Laura

    2014-04-01

    Sensory cilia are often encapsulated by an extracellular matrix (ECM). In Caenorhabditis elegans, Drosophila melanogaster, and vertebrates, this ECM is thought to be directly involved in ciliary mechanosensing by coupling external forces to the ciliary membrane. Drosophila mechano- and chemosensory cilia are both associated with an ECM, indicating that the ECM may have additional roles that go beyond mechanosensory cilium function. Here, we identify Artichoke (ATK), an evolutionarily conserved leucine-rich repeat ECM protein that is required for normal morphogenesis and function of ciliated sensilla in Drosophila. atk is transiently expressed in accessory cells in all ciliated sensory organs during their late embryonic development. Antibody stainings show ATK protein in the ECM that surrounds sensory cilia. Loss of ATK protein in atk null mutants leads to cilium deformation and disorientation in chordotonal organs, apparently without uncoupling the cilia from the ECM, and consequently to locomotion defects. Moreover, impaired chemotaxis in atk mutant larvae suggests that, based on ATK protein localization, the ECM is also crucial for the correct assembly of chemosensory receptors. In addition to defining a novel ECM component, our findings show the importance of ECM integrity for the proper morphogenesis of ciliated organs in different sensory modalities. PMID:24496014

  19. Rapid endocytosis is triggered upon imbibition in Arabidopsis seeds

    OpenAIRE

    Pagnussat, Luciana; Burbach, Christian; Baluška, František; de la Canal, Laura

    2012-01-01

    During seed imbibition and embryo activation, rapid change from a metabolically resting state to the activation of diverse extracellular and/or membrane bound molecules is essential and, hence, endocytosis could be activated too. In fact, we have documented endocytic internalization of the membrane impermeable endocytic tracer FM4–64 already upon 30 min of imbibition of Arabidopsis seeds. This finding suggest that endocytosis is activated early during seed imbibition in Arabidopsis. Immunoloc...

  20. The MTL1 Pentatricopeptide Repeat Protein Is Required for Both Translation and Splicing of the Mitochondrial NADH DEHYDROGENASE SUBUNIT7 mRNA in Arabidopsis.

    Science.gov (United States)

    Haïli, Nawel; Planchard, Noelya; Arnal, Nadège; Quadrado, Martine; Vrielynck, Nathalie; Dahan, Jennifer; des Francs-Small, Catherine Colas; Mireau, Hakim

    2016-01-01

    Mitochondrial translation involves a complex interplay of ancient bacteria-like features and host-derived functionalities. Although the basic components of the mitochondrial translation apparatus have been recognized, very few protein factors aiding in recruiting ribosomes on mitochondria-encoded messenger RNA (mRNAs) have been identified in higher plants. In this study, we describe the identification of the Arabidopsis (Arabidopsis thaliana) MITOCHONDRIAL TRANSLATION FACTOR1 (MTL1) protein, a new member of the Pentatricopeptide Repeat family, and show that it is essential for the translation of the mitochondrial NADH dehydrogenase subunit7 (nad7) mRNA. We demonstrate that mtl1 mutant plants fail to accumulate the Nad7 protein, even though the nad7 mature mRNA is produced and bears the same 5' and 3' extremities as in wild-type plants. We next observed that polysome association of nad7 mature mRNA is specifically disrupted in mtl1 mutants, indicating that the absence of Nad7 results from a lack of translation of nad7 mRNA. These findings illustrate that mitochondrial translation requires the intervention of gene-specific nucleus-encoded PPR trans-factors and that their action does not necessarily involve the 5' processing of their target mRNA, as observed previously. Interestingly, a partial decrease in nad7 intron 2 splicing was also detected in mtl1 mutants, suggesting that MTL1 is also involved in group II intron splicing. However, this second function appears to be less essential for nad7 expression than its role in translation. MTL1 will be instrumental to understand the multifunctionality of PPR proteins and the mechanisms governing mRNA translation and intron splicing in plant mitochondria. PMID:26537562

  1. Arabidopsis Raf-Like Mitogen-Activated Protein Kinase Kinase Kinase Gene Raf43 Is Required for Tolerance to Multiple Abiotic Stresses.

    Directory of Open Access Journals (Sweden)

    Nasar Virk

    Full Text Available Mitogen-activated protein kinase (MAPK cascades are critical signaling modules that mediate the transduction of extracellular stimuli into intracellular response. A relatively large number of MAPKKKs have been identified in a variety of plant genomes but only a few of them have been studied for their biological function. In the present study, we identified an Arabidopsis Raf-like MAPKKK gene Raf43 and studied its function in biotic and abiotic stress response using a T-DNA insertion mutant raf43-1 and two Raf43-overexpressing lines Raf43-OE#1 and Raf43-OE#13. Expression of Raf43 was induced by multiple abiotic and biotic stresses including treatments with drought, mannitol and oxidative stress or defense signaling molecule salicylic acid and infection with necrotrophic fungal pathogen Botrytis cinerea. Seed germination and seedling root growth of raf43-1 were significantly inhibited on MS medium containing mannitol, NaCl, H2O2 or methyl viologen (MV while seed germination and seedling root growth of the Raf43-OE#1 and Raf43-OE#13 lines was similar to wild type Col-0 under the above stress conditions. Soil-grown raf43-1 plants exhibited reduced tolerance to MV, drought and salt stress. Abscisic acid inhibited significantly seed germination and seedling root growth of the raf43-1 line but had no effect on the two Raf43-overexpressing lines. Expression of stress-responsive RD17 and DREB2A genes was significantly down-regulated in raf43-1 plants. However, the raf43-1 and Raf43-overexpressing plants showed similar disease phenotype to the wild type plants after infection with B. cinerea or Pseudomonas syringae pv. tomato DC3000. Our results demonstrate that Raf43, encoding for a Raf-like MAPKKK, is required for tolerance to multiple abiotic stresses in Arabidopsis.

  2. Ethylene signaling is required for the acceleration of cell death induced by the activation of At ME K5 in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hongxia Liu; Ying Wang; Juan Xu; Tongbing Su; Guoqin Liu; Dongtao Ren

    2008-01-01

    Mitogen-activated protein kinases (MAPKs) are involved in the regulation of plant growth, development and responses to a wide variety of stimuli. In a conditional gain-of-function transgenic system, the activation of AtM£K5, a MAPK kinase, can in turn activate endogenous AtMAPK3 and AtMAPK6, and can lead to a striking increase in ethylene production and induce hypersensitive response (HR)-like cell death in Arabidopsis. However, the role of the increased ethylene production in regulating this HR-like cell death remains unknown. Using Arabidopsis transgenic plants that express AtMEK5DD , an active mutant of AtMEK5 that is under the control of a steroid-inducible promoter, we tested the contribution of ethylene to cell death. We found that ethylene biosynthesis occurs before cell death. Cell death was delayed by inhibiting AtMEK5-induced ethylene production using inhibitors of ACC-synthases, ACC-oxidases or ethylene receptors. In the mutants AtMEK5DDletrl-1 and AtMEK5DDlein2-l, both of which showed insen-sitivity to ethylene, the expression of AtMEKSDD protein, activity of AtMAPK3 and AtMAPK6, and ethylene production were the same as those seen in AtMEK.5 transgenic plants, but cell death was also delayed. These data suggest that ethylene signaling perception is required to accelerate cell death that is induced by AtMEK5 activation.

  3. Riboflavin-Induced Disease Resistance Requires the Mitogen-Activated Protein Kinases 3 and 6 in Arabidopsis thaliana

    Science.gov (United States)

    Nie, Shengjun; Xu, Huilian

    2016-01-01

    As a resistance elicitor, riboflavin (vitamin B2) protects plants against a wide range of pathogens. At molecular biological levels, it is important to elucidate the signaling pathways underlying the disease resistance induced by riboflavin. Here, riboflavin was tested to induce resistance against virulent Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000) in Arabidopsis. Results showed that riboflavin induced disease resistance based on MAPK-dependent priming for the expression of PR1 gene. Riboflavin induced transient expression of PR1 gene. However, following Pst DC3000 inoculation, riboflavin potentiated stronger PR1 gene transcription. Further was suggested that the transcript levels of mitogen-activated protein kinases, MPK3 and MPK6, were primed under riboflavin. Upon infection by Pst DC3000, these two enzymes were more strongly activated. The elevated activation of both MPK3 and MPK6 was responsible for enhanced defense gene expression and resistance after riboflavin treatment. Moreover, riboflavin significantly reduced the transcript levels of MPK3 and MPK6 by application of AsA and BAPTA, an H2O2 scavenger and a calcium (Ca2+) scavenger, respectively. In conclusion, MPK3 and MPK6 were responsible for riboflavin-induced resistance, and played an important role in H2O2- and Ca2+-related signaling pathways, and this study could provide a new insight into the mechanistic study of riboflavin-induced defense responses. PMID:27054585

  4. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu

    2011-05-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

  5. BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana.

    Science.gov (United States)

    Hoedemaekers, Karin; Derksen, Jan; Hoogstrate, Suzanne W; Wolters-Arts, Mieke; Oh, Sung-Aeong; Twell, David; Mariani, Celestina; Rieu, Ivo

    2015-04-01

    Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery. PMID:25442716

  6. Arabidopsis inositol 1,3,4-trisphosphate 5/6 kinase 2 is required for seed coat development

    Institute of Scientific and Technical Information of China (English)

    Yong Tang; Shutang Tan; Hongwei Xue

    2013-01-01

    Inositol 1,3,4-trisphosphate 5/6 kinase (ITPK) phosphorylates inositol 1,3,4-trisphosphate to form inositol 1,3,4,5-tetrakisphosphate and inositol 1,3,4,6-tetrakisphosphate which can be finally transferred to inositoi hexaphosphate (IP6) and play important roles during plant growth and development.There are 4 putative ITPK members in Arabidopsis.Expression pattern analysis showed that ITPK2 is constitutively expressed in various tissues.A TDNA knockout mutant of ITPK2 was identified and scanning electron microscopy (SEM) analysis showed that the epidermis structure of seed coat was irregularly formed in seeds of itpk2-1 mutant,resulting in the increased permeability of seed coat to tetrazolium salts.Further analysis by gas chromatography coupled with mass spectrometry of lipid polyester monomers in cell wall confirmed a dramatic decrease in composition of suberin and cutin,which relate to the permeability of seed coat and the formation of which is accompanied with seed coat development.These results indicate that ITPK2 plays an essential role in seed coat development and lipid polyester barrier formation.

  7. YUCCA-mediated auxin biogenesis is required for cell fate transition occurring during de novo root organogenesis in Arabidopsis.

    Science.gov (United States)

    Chen, Lyuqin; Tong, Jianhua; Xiao, Langtao; Ruan, Ying; Liu, Jingchun; Zeng, Minhuan; Huang, Hai; Wang, Jia-Wei; Xu, Lin

    2016-07-01

    Many plant organs have the ability to regenerate a new plant after detachment or wounding via de novo organogenesis. During de novo root organogenesis from Arabidopsis thaliana leaf explants, endogenic auxin is essential for the fate transition of regeneration-competent cells to become root founder cells via activation of WUSCHEL-RELATED HOMEOBOX 11 (WOX11). However, the molecular events from leaf explant detachment to auxin-mediated cell fate transition are poorly understood. In this study, we used an assay to determine the concentration of indole-3-acetic acid (IAA) to provide direct evidence that auxin is produced after leaf explant detachment, a process that involves YUCCA (YUC)-mediated auxin biogenesis. Inhibition of YUC prevents expression of WOX11 and fate transition of competent cells, resulting in the blocking of rooting. Further analysis showed that YUC1 and YUC4 act quickly (within 4 hours) in response to wounding after detachment in both light and dark conditions and promote auxin biogenesis in both mesophyll and competent cells, whereas YUC5, YUC8, and YUC9 primarily respond in dark conditions. In addition, YUC2 and YUC6 contribute to rooting by providing a basal auxin level in the leaf. Overall, our study indicates that YUC genes exhibit a division of labour during de novo root organogenesis from leaf explants in response to multiple signals. PMID:27255928

  8. Arabidopsis PROTEASOME REGULATOR1 is required for auxin-mediated suppression of proteasome activity and regulates auxin signalling.

    Science.gov (United States)

    Yang, Bao-Jun; Han, Xin-Xin; Yin, Lin-Lin; Xing, Mei-Qing; Xu, Zhi-Hong; Xue, Hong-Wei

    2016-01-01

    The plant hormone auxin is perceived by the nuclear F-box protein TIR1 receptor family and regulates gene expression through degradation of Aux/IAA transcriptional repressors. Several studies have revealed the importance of the proteasome in auxin signalling, but details on how the proteolytic machinery is regulated and how this relates to degradation of Aux/IAA proteins remains unclear. Here we show that an Arabidopsis homologue of the proteasome inhibitor PI31, which we name PROTEASOME REGULATOR1 (PTRE1), is a positive regulator of the 26S proteasome. Loss-of-function ptre1 mutants are insensitive to auxin-mediated suppression of proteasome activity, show diminished auxin-induced degradation of Aux/IAA proteins and display auxin-related phenotypes. We found that auxin alters the subcellular localization of PTRE1, suggesting this may be part of the mechanism by which it reduces proteasome activity. Based on these results, we propose that auxin regulates proteasome activity via PTRE1 to fine-tune the homoeostasis of Aux/IAA repressor proteins thus modifying auxin activity. PMID:27109828

  9. Nuclear activity of ROXY1, a glutaredoxin interacting with TGA factors, is required for petal development in Arabidopsis thaliana.

    Science.gov (United States)

    Li, Shutian; Lauri, Andrea; Ziemann, Mark; Busch, Andrea; Bhave, Mrinal; Zachgo, Sabine

    2009-02-01

    Glutaredoxins (GRXs) have thus far been associated mainly with redox-regulated processes participating in stress responses. However, ROXY1, encoding a GRX, has recently been shown to regulate petal primorida initiation and further petal morphogenesis in Arabidopsis thaliana. ROXY1 belongs to a land plant-specific class of GRXs that has a CC-type active site motif, which deviates from ubiquitously occurring CPYC and CGFS GRXs. Expression studies of yellow fluorescent protein-ROXY1 fusion genes driven by the cauliflower mosaic virus 35S promoter reveal a nucleocytoplasmic distribution of ROXY1. We demonstrate that nuclear localization of ROXY1 is indispensable and thus crucial for its activity in flower development. Yeast two-hybrid screens identified TGA transcription factors as interacting proteins, which was confirmed by bimolecular fluorescence complementation experiments showing their nuclear interaction in planta. Overlapping expression patterns of ROXY1 and TGA genes during flower development demonstrate that ROXY1/TGA protein interactions can occur in vivo and support their biological relevance in petal development. Deletion analysis of ROXY1 demonstrates the importance of the C terminus for its functionality and for mediating ROXY1/TGA protein interactions. Phenotypic analysis of the roxy1-2 pan double mutant and an engineered chimeric repressor mutant from PERIANTHIA (PAN), a floral TGA gene, supports a dual role of ROXY1 in petal development. Together, our results show that the ROXY1 protein functions in the nucleus, likely by modifying PAN posttranslationally and thereby regulating its activity in petal primordia initiation. Additionally, ROXY1 affects later petal morphogenesis, probably by modulating other TGA factors that might act redundantly during differentiation of second whorl organs. PMID:19218396

  10. Double Fertilization in Arabidopsis thaliana Involves a Polyspermy Block on the Egg but Not the Central Cell

    Institute of Scientific and Technical Information of China (English)

    Rod J.Scott; Susan J.Armstrong; James Doughty; Melissa Spielman

    2008-01-01

    In animal reproduction,thousands of sperm may compete to fertilize a single egg,but polyspermy blocks prevent multiple fertilization that would otherwise lead to death of the embryo.In flowering plants,successfuI seed development requires that only two sperm are delivered to the embryo sac,where each must fertilize a female gamete(egg or central cell)to produce the embryo and endosperm.Therefore,polyspermy must be avoided,not only to prevent abnormalities in offspring,but to ensure double fertilization.It is not understood how each sperm fertilizes only one female gamete,nor has the existence of polyspermy barriers been directly tested in vivo.Here,we sought evidence for poly-spermy blocks in angiosperms using the polyspermic tetraspore(tes)mutant of Arabidopsis,which allows in-vivo challenge of egg and central cell with multiple male gametes.We show that tes mutant pollen tubes can transmit more than one sperm pair to an embryo sac,and that sperm from more than one pair can participate in fertilization.We detected endosperms but not embryos with ploidies that could only result from multiple fertilization.Our results therefore dem-onstrate an in-vivo polyspermy block on the egg,but not the central cell of a flowering plant.

  11. The Unstructured N-terminal Region of Arabidopsis Group 4 Late Embryogenesis Abundant (LEA) Proteins Is Required for Folding and for Chaperone-like Activity under Water Deficit.

    Science.gov (United States)

    Cuevas-Velazquez, Cesar L; Saab-Rincón, Gloria; Reyes, José Luis; Covarrubias, Alejandra A

    2016-05-13

    Late embryogenesis abundant (LEA) proteins are a conserved group of proteins widely distributed in the plant kingdom that participate in the tolerance to water deficit of different plant species. In silico analyses indicate that most LEA proteins are structurally disordered. The structural plasticity of these proteins opens the question of whether water deficit modulates their conformation and whether these possible changes are related to their function. In this work, we characterized the secondary structure of Arabidopsis group 4 LEA proteins. We found that they are disordered in aqueous solution, with high intrinsic potential to fold into α-helix. We demonstrate that complete dehydration is not required for these proteins to sample ordered structures because milder water deficit and macromolecular crowding induce high α-helix levels in vitro, suggesting that prevalent conditions under water deficit modulate their conformation. We also show that the N-terminal region, conserved across all group 4 LEA proteins, is necessary and sufficient for conformational transitions and that their protective function is confined to this region, suggesting that folding into α-helix is required for chaperone-like activity under water limitation. We propose that these proteins can exist as different conformers, favoring functional diversity, a moonlighting property arising from their structural dynamics. PMID:27006402

  12. Transcriptome Analysis of Arabidopsis Wild-Type and g13-sst sim Trichomes Identifies Four Additional Genes Required for Trichome Development

    Institute of Scientific and Technical Information of China (English)

    M.David Marks; Jonathan R Wenger; Edward Gilding; Ross Jilk; Richard A.Dixon

    2009-01-01

    Transcriptome analyses have been performed on mature trichomes isolated from wild-type Arabidopsis leaves and on leaf trichomes isolated from the g13-sst sire double mutant,which exhibit many attributes of immature trichomes.The mature trichome profile contained many highly expressed genes involved in cell wall synthesis,protein turnover,and abiotic stress response.The most highly expressed genes in the g13-sst sim profile encoded ribosomal proteins and other proteins involved in translation.Comparative analyses showed that all but one of the genes encoding transcription factors previously found to be important for trichome formation,and many other trichome-important genes,were preferentially expressed in g13-sstsim trichomes.The analysis of genes preferentially expressed in g13-sstsim led to the identification of four additional genes required for normal trichome development.One of these was the HDG2 gene,which is a member of the HD-ZIP IV transcription factor gene family.Mutations in this gene did not alter trichome expansion,but did alter mature trichome cell walls.Mutations in BLT resulted in a loss of trichome branch formation.The relationship between bit and the phenotypically identical mutant,sti,was explored.Mutations in PEL3,which was previously shown to be required for development of the leaf cuticle,resulted in the occasional tangling of expanding trichomes.Mutations in another gene encoding a protein with an unknown function altered trichome branch formation.

  13. Expression of univin, a TGF-beta growth factor, requires ectoderm-ECM interaction and promotes skeletal growth in the sea urchin embryo.

    Science.gov (United States)

    Zito, Francesca; Costa, Caterina; Sciarrino, Serafina; Poma, Veronica; Russo, Roberta; Angerer, Lynne M; Matranga, Valeria

    2003-12-01

    Pl-nectin is an ECM protein located on the apical surface of ectoderm cells of Paracentrotus lividus sea urchin embryo. Inhibition of ECM-ectoderm cell interaction by the addition of McAb to Pl-nectin to the culture causes a dramatic impairment of skeletogenesis, offering a good model for the study of factor(s) involved in skeleton elongation and patterning. We showed that skeleton deficiency was not due to a reduction in the number of PMCs ingressing the blastocoel, but it was correlated with a reduction in the number of Pl-SM30-expressing PMCs. Here, we provide evidence on the involvement of growth factor(s) in skeleton morphogenesis. Skeleton-defective embryos showed a strong reduction in the levels of expression of Pl-univin, a growth factor of the TGF-beta superfamily, which was correlated with an equivalent strong reduction in the levels of Pl-SM30. In contrast, expression levels of Pl-BMP5-7 remained low and constant in both skeleton-defective and normal embryos. Microinjection of horse serum in the blastocoelic cavity of embryos cultured in the presence of the antibody rescued skeleton development. Finally, we found that misexpression of univin is also sufficient to rescue defects in skeleton elongation and SM30 expression caused by McAb to Pl-nectin, suggesting a key role for univin or closely related factor in sea urchin skeleton morphogenesis. PMID:14623243

  14. Loading of Arabidopsis centromeric histone CENH3 occurs mainly during G2 and requires the presence of the histone fold domain

    Czech Academy of Sciences Publication Activity Database

    Lermontova, L.; Schubert, V.; Fuchs, J.; Klatte, J.; Macas, Jiří; Schubert, I.

    2006-01-01

    Roč. 18, - (2006), s. 2443-2451. ISSN 1040-4651 Institutional research plan: CEZ:AV0Z50510513 Keywords : histone CENH3 * Arabidopsis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.868, year: 2006

  15. Embryos, microscopes, and society.

    Science.gov (United States)

    Maienschein, Jane

    2016-06-01

    Embryos have different meanings for different people and in different contexts. Seen under the microscope, the biological embryo starts out as one cell and then becomes a bunch of cells. Gradually these divide and differentiate to make up the embryo, which in humans becomes a fetus at eight weeks, and then eventually a baby. At least, that happens in those cases that carry through normally and successfully. Yet a popular public perception imagines the embryo as already a little person in the very earliest stages of development, as if it were predictably to become an adult. In actuality, cells can combine, pull apart, and recombine in a variety of ways and still produce embryos, whereas most embryos never develop into adults at all. Biological embryos and popular imaginations of embryos diverge. This paper looks at some of the historical reasons for and social implications of that divergence. PMID:26996410

  16. DNA repair in mammalian embryos.

    Science.gov (United States)

    Jaroudi, Souraya; SenGupta, Sioban

    2007-01-01

    Mammalian cells have developed complex mechanisms to identify DNA damage and activate the required response to maintain genome integrity. Those mechanisms include DNA damage detection, DNA repair, cell cycle arrest and apoptosis which operate together to protect the conceptus from DNA damage originating either in parental gametes or in the embryo's somatic cells. DNA repair in the newly fertilized preimplantation embryo is believed to rely entirely on the oocyte's machinery (mRNAs and proteins deposited and stored prior to ovulation). DNA repair genes have been shown to be expressed in the early stages of mammalian development. The survival of the embryo necessitates that the oocyte be sufficiently equipped with maternal stored products and that embryonic gene expression commences at the correct time. A Medline based literature search was performed using the keywords 'DNA repair' and 'embryo development' or 'gametogenesis' (publication dates between 1995 and 2006). Mammalian studies which investigated gene expression were selected. Further articles were acquired from the citations in the articles obtained from the preliminary Medline search. This paper reviews mammalian DNA repair from gametogenesis to preimplantation embryos to late gestational stages. PMID:17141556

  17. DETECTION OF CARCINOGENICITY BASED ON MUTAGENICITY IN ARABIDOPSIS

    Science.gov (United States)

    Thirty-seven synthetic chemicals plus two mycotoxins were tested for mutagenicity in an Arabidopsis embryo system. The results of this test, prokaryotic repair tests, bacterial mutation assays, eukaryotic cell systems, and in vivo tests were compared to the carcinogenicity classi...

  18. The bacterial effector DspA/E is toxic in Arabidopsis thaliana and is required for multiplication and survival of fire blight pathogen.

    Science.gov (United States)

    Degrave, Alexandre; Moreau, Manon; Launay, Alban; Barny, Marie-Anne; Brisset, Marie-Noëlle; Patrit, Oriane; Taconnat, Ludivine; Vedel, Regine; Fagard, Mathilde

    2013-06-01

    The type III effector DspA/E is an essential pathogenicity factor of the phytopathogenic bacterium Erwinia amylovora. We showed that DspA/E was required for transient bacterial growth in nonhost Arabidopsis thaliana leaves, as an E. amylovora dspA/E mutant was unable to grow. We expressed DspA/E in A. thaliana transgenic plants under the control of an oestradiol-inducible promoter, and found that DspA/E expressed in planta restored the growth of a dspA/E mutant. DspA/E expression in these transgenic plants led to the modulation by at least two-fold of the expression of 384 genes, mostly induced (324 genes). Both induced and repressed genes contained high proportions of defence genes. DspA/E expression ultimately resulted in plant cell death without requiring a functional salicylic acid signalling pathway. Analysis of A. thaliana transgenic seedlings expressing a green fluorescent protein (GFP):DspA/E fusion indicated that the fusion protein could only be detected in a few cells per seedling, suggesting the degradation or absence of accumulation of DspA/E in plant cells. Consistently, we found that DspA/E repressed plant protein synthesis when injected by E. amylovora or when expressed in transgenic plants. Thus, we conclude that DspA/E is toxic to A. thaliana: it promotes modifications, among which the repression of protein synthesis could be determinant in the facilitation of necrosis and bacterial growth. PMID:23634775

  19. Pollen-Specific Aquaporins NIP4;1 and NIP4;2 Are Required for Pollen Development and Pollination in Arabidopsis thaliana.

    Science.gov (United States)

    Di Giorgio, Juliana Andrea Pérez; Bienert, Gerd Patrick; Ayub, Nicolás Daniel; Yaneff, Agustín; Barberini, María Laura; Mecchia, Martín Alejandro; Amodeo, Gabriela; Soto, Gabriela Cynthia; Muschietti, Jorge Prometeo

    2016-05-01

    In flowers with dry stigmas, pollen development, pollination, and pollen tube growth require spatial and temporal regulation of water and nutrient transport. To better understand the molecular mechanisms involved in reproductive processes, we characterized NIP4;1 and NIP4;2, two pollen-specific aquaporins of Arabidopsis thaliana. NIP4;1 and NIP4;2 are paralogs found exclusively in the angiosperm lineage. Although they have 84% amino acid identity, they displayed different expression patterns. NIP4;1 has low expression levels in mature pollen, while NIP4;2 expression peaks during pollen tube growth. Additionally, NIP4;1pro:GUS flowers showed GUS activity in mature pollen and pollen tubes, whereas NIP4;2pro:GUS flowers only in pollen tubes. Single T-DNA mutants and double artificial microRNA knockdowns had fewer seeds per silique and reduced pollen germination and pollen tube length. Transport assays in oocytes showed NIP4;1 and NIP4;2 function as water and nonionic channels. We also found that NIP4;1 and NIP4;2 C termini are phosphorylated by a pollen-specific CPK that modifies their water permeability. Survival assays in yeast indicated that NIP4;1 also transports ammonia, urea, boric acid, and H2O2 Thus, we propose that aquaporins NIP4;1 and NIP4;2 are exclusive components of the reproductive apparatus of angiosperms with partially redundant roles in pollen development and pollination. PMID:27095837

  20. The Membrane-Associated Sec1/Munc18 KEULE is Required for Phragmoplast Microtubule Reorganization During Cytokinesis in Arabidopsis.

    Science.gov (United States)

    Steiner, Alexander; Müller, Lin; Rybak, Katarzyna; Vodermaier, Vera; Facher, Eva; Thellmann, Martha; Ravikumar, Raksha; Wanner, Gerhard; Hauser, Marie-Theres; Assaad, Farhah F

    2016-04-01

    Cytokinesis, the partitioning of the cytoplasm following nuclear division, requires extensive coordination between membrane trafficking and cytoskeletal dynamics. In plants, the onset of cytokinesis is characterized by the assembly of a bipolar microtubule array, the phragmoplast, and of a transient membrane compartment, the cell plate. Little is known about the coordination between membrane deposition at the cell plate and the dynamics of phragmoplast microtubules. In this study, we monitor the localization dynamics of microtubule and membrane markers throughout cytokinesis. Our spatiotemporal resolution is consistent with the general view that microtubule dynamics drive membrane movements. Nonetheless, we provide evidence for active sorting at the cell plate and show that this is, at least in part, mediated by the TRAPPII tethering complex. We also characterize phragmoplast microtubule organization and cell plate formation in a suite of cytokinesis-defective mutants. Of four mutant lines with defects in phragmoplast microtubule organization, only mor1 microtubule-associated mutants exhibited aberrant cell plates. Conversely, the mutants with the strongest impairment in phragmoplast microtubule reorganization are keule alleles, which have a primary defect in membrane fusion. Our findings identify the SEC1/Munc18 protein KEULE as a central regulatory node in the coordination of membrane and microtubule dynamics during plant cytokinesis. PMID:26700031

  1. SETH1 and SETH2, Two Components of the Glycosylphosphatidylinositol Anchor Biosynthetic Pathway, Are Required for Pollen Germination and Tube Growth in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Lalanne, E.; Honys, David; Johnson, A.; Borner, G. H. H.; Lilley, K. S.; Dupree, P.; Grossniklaus, U.; Twell, D.

    2003-01-01

    Roč. 16, - (2003), s. 229-240. ISSN 1040-4651 R&D Projects: GA AV ČR IAA5038207 Institutional research plan: CEZ:AV0Z5038910 Keywords : Glycosylphosphatidylinositol * Pollen Germination * Arabidopsis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.679, year: 2003

  2. Metabolomic Assessment of Embryo Viability

    OpenAIRE

    Uyar, Asli; Seli, Emre

    2014-01-01

    Preimplantation embryo metabolism demonstrates distinctive characteristics associated with the developmental potential of embryos. On this basis, metabolite content of culture media was hypothesized to reflect the implantation potential of individual embryos. This hypothesis was tested in consecutive studies reporting a significant association between culture media metabolites and embryo development or clinical pregnancy. The need for a noninvasive, reliable, and rapid embryo assessment strat...

  3. HEXOKINASE 1 is required for glucose-induced repression of bZIP63, At5g22920 and BT2 in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sabine eKunz

    2015-07-01

    Full Text Available Simple sugars, like glucose and sucrose, act as signals to modulate the expression of hundreds of genes in plants. Frequently, however, it remains unclear whether this regulation is induced by the sugars themselves or by their derivatives generated in the course of carbohydrate (CH metabolism. In the present study, we tested the relevance of different CH metabolism and allocation pathways affecting expression patterns of five selected sugar-responsive genes (bZIP63, At5g22920, BT2, MGD2 and TPS9 in Arabidopsis thaliana. In general, the expression followed diurnal changes in the overall sugar availability. However, under steady growth conditions, this response was hardly impaired in the mutants for CH metabolizing/ transporting proteins (adg1, sex1, sus1-4, sus5/6 and tpt2, including also hexokinase1 (HXK1 loss- and gain-of-function plants - gin2.1 and oe3.2, respectively. In addition, transgenic plants carrying pbZIP63::GUS showed no changes in reporter-gene-expression when grown on sugar under steady-state conditions. In contrast, short-term treatments of agar-grown seedlings with 1% glucose or sucrose induced pbZIP63::GUS repression, which became even more apparent in seedlings grown in liquid media. Subsequent analyses of liquid-grown gin2.1 and oe3.2 seedlings revealed that glucose-dependent regulation of the five selected genes was not affected in gin2.1, whereas it was enhanced in oe3.2 plants for bZIP63, At5g22920 and BT2. The sugar treatments had no effect on ATP/ADP ratio, suggesting that changes in gene expression were not linked to cellular energy status. Overall, the data suggest that HXK1 does not act as glucose sensor controlling bZIP63, At5g22920 and BT2 expression, but it is nevertheless required for production of a downstream metabolic signal regulating their expression.

  4. Ectopic expression of the Brassica SHOOTMERISTEMLESS attenuates the deleterious effects of the auxin transport inhibitor TIBA on somatic embryo number and morphology.

    Science.gov (United States)

    Elhiti, Mohamed; Stasolla, Claudio

    2011-02-01

    The auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) is a useful compound for investigating the role of auxin flow during plant growth and development. In Arabidopsis lines, applications of TIBA during the induction phase of somatic embryogenesis inhibit embryo development and induce the differentiation of the meristematic cells of the shoot apical meristem (SAM), leading to the fusion of the cotyledons. These abnormalities were associated to changes in the expression levels of auxin transporter genes (PINs) and endogenous distribution of IAA. Treatments of TIBA caused a rapid accumulation of IAA within the epidermal and cortical root cells of the explants (bent-cotyledon zygotic embryos), as well as in the apical and sub-apical cells of the callus generated by the surface of the cotyledons of the explants. Within the callus only a few cells acquired meristematic characteristics, and this was associated to low expression levels of genes involved in embryogenic cell fate acquisition, such as WUSCHEL (WUS), LEAFY COTYLEDON 1 and 2. All these deleterious effects were attenuated when TIBA was administered to lines over-expressing SHOOT MERISTEMLESS (STM) isolated from Brassica oleracea (Bo), B. napus (Bn), and B. rapa (Br). Of interest, TIBA-treated explants of Arabidopsis lines over-expressing the Brassica STM were able to produce a large number of embryogenic cells and somatic embryos which exhibited a normal morphology and two distinct cotyledons. A proposed reason for this behaviour was ascribed to the ability of the transformed tissue to retain a normal distribution of auxin in the presence of TIBA. Proper localization of auxin might be required for the normal expression of several genes needed for the acquisition of embryogenic competence and formation of somatic embryos. PMID:21421384

  5. Embryo Form Project: An original technique for the three-dimensional reconstruction of human embryo morphology.

    Science.gov (United States)

    Labrousse, M; Micard, E; Tonnelet, R; Cendre, R; Delmas, V; Naidich, T; Braun, M

    2015-12-01

    Our current knowledge on the developmental stages of human embryogenesis has derived from limited numbers of classical studies. Computer technology now permits accurate 3D reconstruction of embryo morphology from serial histological sections. We present a successful technique that uses either fresh or preserved serial histological sections to generate highly detailed 3D image reconstructions of very small human embryos. We present the data we obtained from the reconstruction in virtual space of previously sectioned 15 and 22.5mm embryos. Their morphologies were studied using a DICOM viewer which permitted the analysis of any specific structure in any required orientation. To our knowledge, this is the first time human embryos have been reconstructed in this way. We believe that this reconstruction technique could improve our knowledge on embryo morphogenesis, especially if coupled to the study of genes involved in embryonic development. It may also prove to be a useful pedagogical tool. PMID:26219247

  6. Vitrification-based cryopreservation of Drosophila embryos

    Energy Technology Data Exchange (ETDEWEB)

    Schreuders, P.D.; Mazur, P. [Oak Ridge National Lab., TN (United States)

    1994-12-31

    Currently, over 30,000 strains of Drosophila melanogaster are maintained by geneticists through regular transfer of breeding stocks. A more cost effective solution is to cryopreserve their embryos. Cooling and warming rates >10,000{degrees}C/min. are required to prevent chilling injury. To avoid the lethal intracellular ice normally produced at such high cooling rates, it is necessary to use {ge}50% (w/w) concentrations of glass-inducing solutes to vitrify the embryos. Differential scanning calorimetry (DSC) is used to develop and evaluate ethylene glycol and polyvinyl pyrrolidone based vitrification solutions. The resulting solution consists of 8.5M ethylene glycol + 10% polyvinylpyrrolidone in D-20 Drosophila culture medium. A two stage method is used for the introduction and concentration of these solutes within the embryo. The method reduces the exposure time to the solution and, consequently, reduces toxicity. Both DSC and freezing experiments suggest that, while twelve-hour embryos will vitrify using cooling rates >200{degrees}C/min., they will devitrify and be killed with even moderately rapid warming rates of {approximately}1,900{degrees}C/min. Very rapid warming ({approximately}100,000{degrees}C/min.) results in variable numbers of successfully cryopreserved embryos. This sensitivity to warming rite is typical of devitrification. The variability in survival is reduced using embryos of a precisely determined embryonic stage. The vitrification of the older, fifteen-hour, embryos yields an optimized hatching rate of 68%, with 35 - 40% of the resulting larvae developing to normal adults. This Success rite in embryos of this age may reflect a reduced sensitivity to limited devitrification or a more even distribution of the ethylene glycol within the embryo.

  7. WOX2 and polar auxin transport during spruce embryo pattern formation

    OpenAIRE

    Palovaara, Joakim; Hakman, Inger

    2009-01-01

    The WOX family of transcription factors and polar auxin transport (PAT) are both essential for embryonic patterning and thus normal embryo development in angiosperms. Recent analysis by us of WOX-related genes in Picea and Pinus suggests that they play fundamental roles during embryo development also in conifers.1 It has been proposed that there is a connection between the spatial separation of WOX2 and WOX8, and PAT in the formation of the apical-basal axis in Arabidopsis embryos and that bo...

  8. A plasma membrane H+-ATPase is required for the formation of proanthocyanidins in the seed coat endothelium of Arabidopsis thaliana

    OpenAIRE

    Ivan R Baxter; Young, Jeffery C.; Armstrong, Gordon; Foster, Nathan; Bogenschutz, Naomi; Cordova, Tatiana; Peer, Wendy Ann; Hazen, Samuel P.; Murphy, Angus S.; Harper, Jeffrey F.

    2005-01-01

    The plasma membrane in plant cells is energized with an electrical potential and proton gradient generated through the action of H+ pumps belonging to the P-type ATPase superfamily. The Arabidopsis genome encodes 11 plasma membrane H+ pumps. Auto-inhibited H+-ATPase isoform 10 (AHA10) is expressed primarily in developing seeds. Here we show that four independent gene disruptions of AHA10 result in seed coats with a transparent testa (tt) phenotype (light-colored seeds). A quantitative analysi...

  9. Arabidopsis VILLIN2 and VILLIN3 Are Required for the Generation of Thick Actin Filament Bundles and for Directional Organ Growth[C][W

    Science.gov (United States)

    van der Honing, Hannie S.; Kieft, Henk; Emons, Anne Mie C.; Ketelaar, Tijs

    2012-01-01

    In plant cells, actin filament bundles serve as tracks for myosin-dependent organelle movement and play a role in the organization of the cytoplasm. Although virtually all plant cells contain actin filament bundles, the role of the different actin-bundling proteins remains largely unknown. In this study, we investigated the role of the actin-bundling protein villin in Arabidopsis (Arabidopsis thaliana). We used Arabidopsis T-DNA insertion lines to generate a double mutant in which VILLIN2 (VLN2) and VLN3 transcripts are truncated. Leaves, stems, siliques, and roots of vln2 vln3 double mutant plants are twisted, which is caused by local differences in cell length. Microscopy analysis of the actin cytoskeleton showed that in these double mutant plants, thin actin filament bundles are more abundant while thick actin filament bundles are virtually absent. In contrast to full-length VLN3, truncated VLN3 lacking the headpiece region does not rescue the phenotype of the vln2 vln3 double mutant. Our results show that villin is involved in the generation of thick actin filament bundles in several cell types and suggest that these bundles are involved in the regulation of coordinated cell expansion. PMID:22209875

  10. Arabidopsis VILLIN2 and VILLIN3 are required for the generation of thick actin filament bundles and for directional organ growth.

    Science.gov (United States)

    van der Honing, Hannie S; Kieft, Henk; Emons, Anne Mie C; Ketelaar, Tijs

    2012-03-01

    In plant cells, actin filament bundles serve as tracks for myosin-dependent organelle movement and play a role in the organization of the cytoplasm. Although virtually all plant cells contain actin filament bundles, the role of the different actin-bundling proteins remains largely unknown. In this study, we investigated the role of the actin-bundling protein villin in Arabidopsis (Arabidopsis thaliana). We used Arabidopsis T-DNA insertion lines to generate a double mutant in which VILLIN2 (VLN2) and VLN3 transcripts are truncated. Leaves, stems, siliques, and roots of vln2 vln3 double mutant plants are twisted, which is caused by local differences in cell length. Microscopy analysis of the actin cytoskeleton showed that in these double mutant plants, thin actin filament bundles are more abundant while thick actin filament bundles are virtually absent. In contrast to full-length VLN3, truncated VLN3 lacking the headpiece region does not rescue the phenotype of the vln2 vln3 double mutant. Our results show that villin is involved in the generation of thick actin filament bundles in several cell types and suggest that these bundles are involved in the regulation of coordinated cell expansion. PMID:22209875

  11. Evaluation of Sheep Embryo Quality by Morphologic Methods – Advantages and Disadvantages

    Directory of Open Access Journals (Sweden)

    S. Angela

    2006-01-01

    Full Text Available The present study is focused on one of the most important steps in embryo technology evaluating embryo quality. During three years, we have conducted embryo transfer experiments on sheep. The evaluation of embryo quality was made using morphologic methods. We have evaluated embryos immediately after recovery (surgical methods recovery or after throwing of frozen embryo under a optical microscope were used for evaluation. International Embryo Transfer Society standards for embryo quality classification. There are four grades of quality: excellent, good, medium and poor. The morphological method’s advantages are: it is very fast, not so expensive and does not require excessive embryo manipulation. Disadvantages of this method are: grading is subjective, depending on the experience of the evaluator, metabolic, genetic or epigenetic disorders of embryos are not detectable.

  12. Requirement of nuclear localization and transcriptional activity of p53 for its targeting to the yolk syncytial layer (YSL) nuclei in zebrafish embryo and its use for apoptosis assay

    International Nuclear Information System (INIS)

    We expressed zebrafish p53 protein fused to GFP by a neuron-specific HuC promoter in zebrafish embryos. Instead of displaying neuronal expression patterns, p53-GFP was targeted to zebrafish YSL nuclei. This YSL targeting is p53 sequence-specific because GFP fusion proteins of p63 and p73 displayed neuronal-specific patterns. To dissect the underlying mechanisms, various constructs encoding a series of p53 mutant proteins under the control of different promoters were generated. Our results showed that expression of p53, in early zebrafish embryo, is preferentially targeted to the nuclei of YSL, which is mediated by importin. Similarly, this targeting is abrogated when p53 nuclear localization signal is disrupted. In addition, the transcriptional activity of p53 is required for this targeting. We further showed that fusion of pro-apoptotic BAD protein to p53-GFP led to apoptosis of YSL cells, and subsequent imperfect microtubule formation and abnormal blastomere movements

  13. Tissue morphodynamics shaping the early mouse embryo.

    Science.gov (United States)

    Sutherland, Ann E

    2016-07-01

    Generation of the elongated vertebrate body plan from the initially radially symmetrical embryo requires comprehensive changes to tissue form. These shape changes are generated by specific underlying cell behaviors, coordinated in time and space. Major principles and also specifics are emerging, from studies in many model systems, of the cell and physical biology of how region-specific cell behaviors produce regional tissue morphogenesis, and how these, in turn, are integrated at the level of the embryo. New technical approaches have made it possible more recently, to examine the morphogenesis of the mouse embryo in depth, and to elucidate the underlying cellular mechanisms. This review focuses on recent advances in understanding the cellular basis for the early fundamental events that establish the basic form of the embryo. PMID:26820524

  14. Risks of spontaneously and IVF-conceived singleton and twin pregnancies differ, requiring reassessment of statistical premises favoring elective single embryo transfer (eSET).

    Science.gov (United States)

    Gleicher, Norbert; Kushnir, Vitally A; Barad, David H

    2016-01-01

    A published review of the literature by Dutch investigators in 2004 suggested significant outcome differences between spontaneously - and in vitro fertilization (IVF) - conceived singleton and twin pregnancies. Here we review whether later studies between 2004-2015 confirmed these findings. Though methodologies of here reviewed studies varied, and all were retrospective, they overall confirmed results of the 2004 review, and supported significant outcome variances between spontaneously- and IVF-conceived pregnancies: IVF singletons demonstrate significantly poorer and IVF twins significantly better perinatal outcomes than spontaneously conceived singletons and twins, with differences stable over time, and with overall obstetrical outcomes significantly improved. Exaggerations of severe IVF twin risks are likely in the 50 % range, while exaggerations of milder perinatal risks are approximately in 25 % range. Though elective single embryo transfers (eSET) have been confirmed to reduce pregnancy chances, they are, nevertheless, increasingly utilized. eSET, equally unquestionably, however, reduces twin pregnancies. Because twin pregnancies have been alleged to increase outcome risks in comparison to singleton pregnancies, here reported findings should affect the ongoing discussion whether increased twin risks are factual. With no risk excess, eSET significantly reduces IVF pregnancy chances without compensatory benefits and, therefore, is not advisable in IVF, unless patients do not wish to conceive twins or have medical contraindications to conceiving twins. PMID:27142226

  15. GAMETOPHYTIC FACTOR 1, Involved in Pre-mRNA Splicing, Is Essential for Megagametogenesis and Embryogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Man Liu; Li Yuan; Nai-You Liu; Dong-Qiao Shi; Jie Liu; Wei-Cai Yang

    2009-01-01

    RNA biogenesis is essential and vital for accurate expression of genes. It is obvious that cells cannot continue normal metabolism when RNA splicing is interfered with. sgt13018 is such a mutant, with partial loss of function of GAMETOPHYTIC FACTOR 1 (GFA1); a gene likely involved in RNA biogenesis in Arabidopsis. The mutant is featured in the phenotype of diminished female gametophyte development at stage FG5 and is associated with the arrest of early embryo development in Arabidopsis. Bioinformatics data showed that homoiogs of gene GFA1 in yeast and human encode putative U5 snRNPspecific proteins required for pre-mRNA splicing. Furthermore, the result of yeast two-hybrid assay indicated that GFA1 physically interacted with AtBrr2 and AtPrp8, the putative U5 snRNP components, of Arabidopsis. This investigation suggests that GFA1 is involved in mRNA biogenesis through interaction with AtBrr2 and AtPrp8 and functions in megagametogeneeis and embryogenesis in plant.

  16. Expression of connexins in human preimplantation embryos in vitro

    OpenAIRE

    Leese Henry J; Traub Otto; Kibschull Mark; Wilson Yvonne; Bloor Debra J; Winterhager Elke; Kimber Susan J

    2004-01-01

    Abstract Intercellular communication via gap junctions is required to coordinate developmental processes in the mammalian embryo. We have investigated if the connexin (Cx) isoforms known to form gap junctions in rodent preimplantation embryos are also expressed in human embryos, with the aim of identifying species differences in communication patterns in early development. Using a combination of polyA PCR and immunocytochemistry we have assessed the expression of Cx26, Cx31, Cx32, Cx40, Cx43 ...

  17. Arabidopsis CDS blastp result: AK243514 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 2e-36 ...

  18. Arabidopsis CDS blastp result: AK243244 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 2e-26 ...

  19. Arabidopsis CDS blastp result: AK287666 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 1e-40 ...

  20. Arabidopsis CDS blastp result: AK242268 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 1e-40 ...

  1. Arabidopsis CDS blastp result: AK243585 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 6e-18 ...

  2. Arabidopsis CDS blastp result: AK288271 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 5e-25 ...

  3. Arabidopsis CDS blastp result: AK287632 [KOME

    Lifescience Database Archive (English)

    Full Text Available n contains Pfam PF02365: No apical meristem (NAM) domain; No apical meristem gene (NAM), required for pattern formation in embryos and flowers-Petunia hybrida, PATCHX:E205713 5e-11 ...

  4. JMJ14, a JmjC domain protein, is required for RNA silencing and cell-to-cell movement of an RNA silencing signal in Arabidopsis

    OpenAIRE

    Searle, I.R.; Melnyk, C. W.; Baulcombe, D. C.; Smith, L. M.; Pontes, O.

    2010-01-01

    JMJ14 is a histone H3 Lys4 (H3K4) trimethyl demethylase that affects mobile RNA silencing in an Arabidopsis transgene system. It also influences CHH DNA methylation, abundance of endogenous transposon transcripts, and flowering time. JMJ14 acts at a point in RNA silencing pathways that is downstream from RNA-dependent RNA polymerase 2 (RDR2) and Argonaute 4 (AGO4). Our results illustrate a link between RNA silencing and demethylation of histone H3 trimethylysine. We propose that JMJ14 acts do...

  5. Embryo-maternal communication

    DEFF Research Database (Denmark)

    Østrup, Esben; Hyttel, Poul; Østrup, Olga

    2011-01-01

    Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms...... directing the placentation. An increasing knowledge of the embryo-maternal communication might not only help to improve the fertility of our farm animals but also our understanding of human health and reproduction....

  6. Arabidopsis TAF1 is an MRE11-interacting protein required for resistance to genotoxic stress and viability of the male gametophyte.

    Science.gov (United States)

    Waterworth, Wanda M; Drury, Georgina E; Blundell-Hunter, George; West, Christopher E

    2015-11-01

    Repair of DNA double-strand breaks (DSBs) by recombination pathways is essential for plant growth and fertility. The recombination endonuclease MRE11 plays important roles in sensing and repair of DNA DSBs. Here we demonstrate protein interaction between Arabidopsis MRE11 and the histone acetyltransferase TAF1, a TATA-binding protein Associated Factor (TAF) of the RNA polymerase II transcription initiation factor complex TFIID. Arabidopsis has two TAF1 homologues termed TAF1 and TAF1b and mutant taf1b lines are viable and fertile. In contrast, taf1 null mutations are lethal, demonstrating that TAF1 is an essential gene. Heterozygous taf1+/- plants display abnormal segregation of the mutant allele resulting from defects in pollen tube development, indicating that TAF1 is important for gamete viability. Characterization of an allelic series of taf1 lines revealed that hypomorphic mutants are viable but display developmental defects and reduced plant fertility. Hypersensitivity of taf1 mutants lacking the C-terminal bromodomain to X-rays and mitomycin C, but not to other forms of abiotic stress, established a specific role for TAF1 in plant DNA repair processes. Collectively these studies reveal a function for TAF1 in plant resistance to genotoxic stress, providing further insight into the molecular mechanisms of the DNA damage response in plants. PMID:26358508

  7. Floral Induction in Arabidopsis by FLOWERING LOCUS T Requires Direct Repression of BLADE-ON-PETIOLE Genes by the Homeodomain Protein PENNYWISE.

    Science.gov (United States)

    Andrés, Fernando; Romera-Branchat, Maida; Martínez-Gallegos, Rafael; Patel, Vipul; Schneeberger, Korbinian; Jang, Seonghoe; Altmüller, Janine; Nürnberg, Peter; Coupland, George

    2015-11-01

    Flowers form on the flanks of the shoot apical meristem (SAM) in response to environmental and endogenous cues. In Arabidopsis (Arabidopsis thaliana), the photoperiodic pathway acts through FLOWERING LOCUS T (FT) to promote floral induction in response to day length. A complex between FT and the basic leucine-zipper transcription factor FD is proposed to form in the SAM, leading to activation of APETALA1 and LEAFY and thereby promoting floral meristem identity. We identified mutations that suppress FT function and recovered a new allele of the homeodomain transcription factor PENNYWISE (PNY). Genetic and molecular analyses showed that ectopic expression of BLADE-ON-PETIOLE1 (BOP1) and BOP2, which encode transcriptional coactivators, in the SAM during vegetative development, confers the late flowering of pny mutants. In wild-type plants, BOP1 and BOP2 are expressed in lateral organs close to boundaries of the SAM, whereas in pny mutants, their expression occurs in the SAM. This ectopic expression lowers FD mRNA levels, reducing responsiveness to FT and impairing activation of APETALA1 and LEAFY. We show that PNY binds to the promoters of BOP1 and BOP2, repressing their transcription. These results demonstrate a direct role for PNY in defining the spatial expression patterns of boundary genes and the significance of this process for floral induction by FT. PMID:26417007

  8. HrpNEa -induced deterrent effect on phloem feeding of the green peach aphid Myzus persicae requires AtGSL5 and AtMYB44 genes in Arabidopsis thaliana

    Indian Academy of Sciences (India)

    Beibei Lü; Weiwei Sun; Shuping Zhang; Chunling Zhang; Jun Qian; Xiaomeng Wang; Rong Gao; Hansong Dong

    2011-03-01

    In Arabidopsis thaliana (Arabidopsis) treated with the harpin protein HrpNEa, resistance to the green peach aphid Myzus persicae, a generalist phloem-feeding insect, develops with induced expression of the AtMYB44 gene. Special GLUCAN SYNTHESIS-LIKE (GSL) genes and -1,3-glucan callose play an important role in plant defence responses to attacks by phloem-feeding insects. Here we report that AtGLS5 and AtMYB44 are both required for HrpNEa-induced repression of M. persicae feeding from the phloem of Arabidopsis leaves. In 24 h successive surveys on large-scale aphid populations, the proportion of feeding aphids was much smaller in HrpNEa-treated plants than in control plants, and aphids preferred to feed from the 37 tested atgsl mutants rather than the wild-type plant. The atgsl mutants were generated previously by mutagenesis in 12 identified AtGSL genes (AtGSL1 through AtGSL12); in the 24 h survey, both atgsl5 and atgsl6 tolerated aphid feeding, and atgsl5 was the most tolerant. Consistently, atgsl5 was also most inhibitive to the deterrent effect of HrpNEa on the phloem-feeding activity of aphids as monitored by the electrical penetration graph technique. These results suggested an important role of the AtGSL5 gene in the effect of HrpNEa. In response to HrpNEa, AtGSL5 expression and callose deposition were induced in the wild-type plant but not in atgsl5. In response to HrpNEa, moreover, the AtMYB44 gene known to be required for repression of aphid reproduction on the plant was also required for repression of the phloem-feeding activity. Small amounts of the AtGSL5 transcript and callose deposition were detected in the atmyb44 mutant, as in atgsl5. Both mutants performed similarly in tolerating the phloem-feeding activity and impairing the deterrent effect of HrpNEa, suggesting that AtGSL5 and AtMYB44 both contributed to the effect.

  9. Can Chlamydia abortus be transmitted by embryo transfer in goats?

    Science.gov (United States)

    Oseikria, M; Pellerin, J L; Rodolakis, A; Vorimore, F; Laroucau, K; Bruyas, J F; Roux, C; Michaud, S; Larrat, M; Fieni, F

    2016-10-01

    infected donor goats to healthy recipients and/or their offspring. Nevertheless, the detection of C. abortus DNA by polymerase chain reaction does not prove that the bacteria found was infectious. Further studies are required to investigate whether enzymatic and/or antibiotic treatment of caprine embryos infected by C. abortus would eliminate the bacteria from the ZP. PMID:27341774

  10. The Essential Gene EMB1611 Maintains Shoot Apical Meristem Function During Arabidopsis Development

    Science.gov (United States)

    The Arabidopsis thaliana genome contains hundreds of genes essential for seed development. Because null mutations in these genes cause embryo lethality, their specific molecular and developmental functions are largely unknown. Here, we identify a role for EMB1611/MEE22, an essential gene in Arabidop...

  11. Oxygen diffusion in fish embryos

    NARCIS (Netherlands)

    Kranenbarg, S.

    2002-01-01

    All vertebrate embryos pass through a developmental period of remarkably low morphological variability. This period has been called phylotypic period. During the phylotypic period, organogenesis takes place, including blood vessel development. Before the phylotypic period, the embryos

  12. The First Human Cloned Embryo.

    Science.gov (United States)

    Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

    2002-01-01

    Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

  13. WUSCHEL-RELATED HOMEOBOX 8/9 is important for proper embryo patterning in the gymnosperm Norway spruce

    OpenAIRE

    Zhu, Tianqing; Moschou, Panagiotis N.; Alvarez, José M.; Sohlberg, Joel J.; Von Arnold, Sara

    2014-01-01

    Proper embryo development is crucial as that is when the primary body axes are established. In Arabidopsis, AtWOX8 and AtWOX9, members of the WUSCHEL-RELATED HOMEOBOX (WOX) gene family, are critical for embryo development. In Norway spruce, PaWOX8/9, which is expressed in embryos, is the homologue of AtWOX8 and AtWOX9. In this work, it is shown that the transcript abundance of PaWOX8/9 is high during early and late embryogeny and that it decreases when the maturation phase starts. To address ...

  14. [Successful pregnancies after oocyte and embryo vitrification].

    Science.gov (United States)

    Salazar, Francisco Hernández; Loza, Erik Omar Okhuysen; Lucas, Maria Teresa Huerta J; Gutiérrez, Gustavo Romero

    2008-02-01

    Cryopreservation of human oocytes represents a solution for ethic conflict about frozen embryo storage for patients with risk to develop ovarian hyperstimulation syndrome; also is an available technique to preserve fertility in women with cancer under treatment, in poor response patients, in case of premature ovarian failure or aging and for other medical or social conditions that require to delay pregnancies, as well as to make easier oocyte donation programs. This paper reports two cases of successful pregnancies after embryo and oocyte vitrification, as well as their results. The technique of vitrification with the cryotop method is an excellent alternative, efficient, fast and cheap for oocyte and embryo cryopreservation with high ranges of fertilization, cleavage and pregnancies with a normal evolution. PMID:18798404

  15. The cytokinin response factors modulate root and shoot growth and promote leaf senescence in Arabidopsis.

    Science.gov (United States)

    Raines, Tracy; Shanks, Carly; Cheng, Chia-Yi; McPherson, Duncan; Argueso, Cristiana T; Kim, Hyo J; Franco-Zorrilla, José M; López-Vidriero, Irene; Solano, Roberto; Vaňková, Radomíra; Schaller, G Eric; Kieber, Joseph J

    2016-01-01

    The cytokinin response factors (CRFs) are a group of related AP2/ERF transcription factors that are transcriptionally induced by cytokinin. Here we explore the role of the CRFs in Arabidopsis thaliana growth and development by analyzing lines with decreased and increased CRF function. While single crf mutations have no appreciable phenotypes, disruption of multiple CRFs results in larger rosettes, delayed leaf senescence, a smaller root apical meristem (RAM), reduced primary and lateral root growth, and, in etiolated seedlings, shorter hypocotyls. In contrast, overexpression of CRFs generally results in the opposite phenotypes. The crf1,2,5,6 quadruple mutant is embryo lethal, indicating that CRF function is essential for embryo development. Disruption of the CRFs results in partially insensitivity to cytokinin in a root elongation assay and affects the basal expression of a significant number of cytokinin-regulated genes, including the type-A ARRs, although it does not impair the cytokinin induction of the type-A ARRs. Genes encoding homeobox transcription factors are mis-expressed in the crf1,3,5,6 mutant, including STIMPY/WOX9 that is required for root and shoot apical meristem maintenance roots and which has previously been linked to cytokinin. These results indicate that the CRF transcription factors play important roles in multiple aspects of plant growth and development, in part through a complex interaction with cytokinin signaling. PMID:26662515

  16. Integrating the genetic and physical maps of Arabidopsis thaliana: identification of mapped alleles of cloned essential (EMB genes.

    Directory of Open Access Journals (Sweden)

    David Meinke

    Full Text Available The classical genetic map of Arabidopsis includes more than 130 genes with an embryo-defective (emb mutant phenotype. Many of these essential genes remain to be cloned. Hundreds of additional EMB genes have been cloned and catalogued (www.seedgenes.org but not mapped. To facilitate EMB gene identification and assess the current level of saturation, we updated the classical map, compared the physical and genetic locations of mapped loci, and performed allelism tests between mapped (but not cloned and cloned (but not mapped emb mutants with similar chromosome locations. Two hundred pairwise combinations of genes located on chromosomes 1 and 5 were tested and more than 1100 total crosses were screened. Sixteen of 51 mapped emb mutants examined were found to be disrupted in a known EMB gene. Alleles of a wide range of published EMB genes (YDA, GLA1, TIL1, AtASP38, AtDEK1, EMB506, DG1, OEP80 were discovered. Two EMS mutants isolated 30 years ago, T-DNA mutants with complex insertion sites, and a mutant with an atypical, embryo-specific phenotype were resolved. The frequency of allelism encountered was consistent with past estimates of 500 to 1000 EMB loci. New EMB genes identified among mapped T-DNA insertion mutants included CHC1, which is required for chromatin remodeling, and SHS1/AtBT1, which encodes a plastidial nucleotide transporter similar to the maize Brittle1 protein required for normal endosperm development. Two classical genetic markers (PY, ALB1 were identified based on similar map locations of known genes required for thiamine (THIC and chlorophyll (PDE166 biosynthesis. The alignment of genetic and physical maps presented here should facilitate the continued analysis of essential genes in Arabidopsis and further characterization of a broad spectrum of mutant phenotypes in a model plant.

  17. Ovarian stimulation and embryo quality

    NARCIS (Netherlands)

    Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

    2009-01-01

    To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

  18. LIF and TNF alpha concentrations in embryo culture media are predictive for embryo implantation in IVF

    Institute of Scientific and Technical Information of China (English)

    Ursula Zollner; Sonja Bischofs; Irena Lalic; Klaus-Peter Zollner

    2012-01-01

    Objective:There is strong evidence that the cytokines leucemia inhibitory factor (LIF) and tumor necrosis factor (TNF) alpha are related to embryo development and implantation. The aim of this study was to determine the levels of LIF and TNF alpha in embryo culture media and to assess its relationship to the outcome of in-vitro fertilization and embryo transfer. Methods:A total of 99 patients were included in this prospective trial and underwent either IVF or ICSI procedure. A total of 865 oocytes were collected. Embryos were cultured in sequential media until day 5. A standardized morphology evaluation of all embryos, including a detailed pronuclear scoring, was performed daily during this period followed by the replacement of one or two selected embryos. Collected embryo culture fluids of days 3 and 5 were analysed for LIF and TNF alpha on days 3 and 5. Results:Mean TNF alpha concentration in culture media on day 3 was 0.54 and 0.37 pg/mL on day 5 and was significantly lower in women conceiving than in not conceiving (0.43 pg/mL versus 0.59 pg/mL on day 3). Mean LIF concentration on day 3 was 31.5 pg/mL and 35.5 pg/mL on day 5 and was significantly higher in women conceiving (56.2 pg/mL versus 22.2 pg/mL on day 3). Conclusions:The results indicate that LIF could have a function in early embryogenesis and as a factor required for embryo implantation. High TNF alpha concentrations seem to be predictive of implantation failure.

  19. Arabidopsis AtRRP44A is the functional homolog of Rrp44/Dis3, an exosome component, is essential for viability and is required for RNA processing and degradation.

    Directory of Open Access Journals (Sweden)

    Naoyoshi Kumakura

    Full Text Available The RNA exosome is a multi-subunit complex that is responsible for 3' to 5' degradation and processing of cellular RNA. Rrp44/Dis3 is the catalytic center of the exosome in yeast and humans. However, the role of Rrp44/Dis3 homologs in plants is still unidentified. Here, we show that Arabidopsis AtRRP44A is the functional homolog of Rrp44/Dis3, is essential for plant viability and is required for RNA processing and degradation. We characterized AtRRP44A and AtRRP44B/SOV, two predicted Arabidopsis Rrp44/Dis3 homologs. AtRRP44A could functionally replace S. cerevisiae Rrp44/Dis3, but AtRRP44B/SOV could not. rrp44a knock-down mutants showed typical phenotypes of exosome function deficiency, 5.8S rRNA 3' extension and rRNA maturation by-product over-accumulation, but rrp44b mutants did not. Conversely, AtRRP44B/SOV mutants showed elevated levels of a selected mRNA, on which rrp44a did not have detectable effects. Although T-DNA insertion mutants of AtRRP44B/SOV had no obvious phenotype, those of AtRRP44A showed defects in female gametophyte development and early embryogenesis. These results indicate that AtRRP44A and AtRRP44B/SOV have independent roles for RNA turnover in plants.

  20. Catalytically-inactive beta-amylase BAM4 required for starch breakdown in Arabidopsis leaves is a starch-binding-protein.

    Science.gov (United States)

    Li, Jing; Francisco, Perigio; Zhou, Wenxu; Edner, Christoph; Steup, Martin; Ritte, Gerhard; Bond, Charles S; Smith, Steven M

    2009-09-01

    Of the four chloroplast beta-amylase (BAM) proteins identified in Arabidopsis, BAM3 and BAM4 were previously shown to play the major roles in leaf starch breakdown, although BAM4 apparently lacks key active site residues and beta-amylase activity. Here we tested multiple BAM4 proteins with different N-terminal sequences with a range of glucan substrates and assay methods, but detected no alpha-1,4-glucan hydrolase activity. BAM4 did not affect BAM1, BAM2 or BAM3 activity even when added in 10-fold excess, nor the BAM3-catalysed release of maltose from isolated starch granules in the presence of glucan water dikinase. However, BAM4 binds to amylopectin and to amylose-Sepharose whereas BAM2 has very low beta-amylase activity and poor glucan binding. The low activity of BAM2 may be explained by poor glucan binding but absence of BAM4 activity is not. These results suggest that BAM4 facilitates starch breakdown by a mechanism involving direct interaction with starch or other alpha-1,4-glucan. PMID:19664588

  1. The Arabidopsis MUM2 gene encodes a beta-galactosidase required for the production of seed coat mucilage with correct hydration properties.

    Science.gov (United States)

    Dean, Gillian H; Zheng, Huanquan; Tewari, Jagdish; Huang, Jun; Young, Diana S; Hwang, Yeen Ting; Western, Tamara L; Carpita, Nicholas C; McCann, Maureen C; Mansfield, Shawn D; Haughn, George W

    2007-12-01

    Seed coat development in Arabidopsis thaliana involves a complex pathway where cells of the outer integument differentiate into a highly specialized cell type after fertilization. One aspect of this developmental process involves the secretion of a large amount of pectinaceous mucilage into the apoplast. When the mature seed coat is exposed to water, this mucilage expands to break the primary cell wall and encapsulate the seed. The mucilage-modified2 (mum2) mutant is characterized by a failure to extrude mucilage on hydration, although mucilage is produced as normal during development. The defect in mum2 appears to reside in the mucilage itself, as mucilage fails to expand even when the barrier of the primary cell wall is removed. We have cloned the MUM2 gene and expressed recombinant MUM2 protein, which has beta-galactosidase activity. Biochemical analysis of the mum2 mucilage reveals alterations in pectins that are consistent with a defect in beta-galactosidase activity, and we have demonstrated that MUM2 is localized to the cell wall. We propose that MUM2 is involved in modifying mucilage to allow it to expand upon hydration, establishing a link between the galactosyl side-chain structure of pectin and its physical properties. PMID:18165329

  2. Potency requirements of rabies vaccines administered intradermally using the Thai Red Cross regimen: investigation of the immunogenicity of serially diluted purified chick embryo cell rabies vaccine.

    Science.gov (United States)

    Beran, Jiri; Honegr, Karel; Banzhoff, Angelika; Malerczyk, Claudius

    2005-06-10

    To determine the minimum vaccine potency per intradermal dose required to elicit an adequate immune response using the Thai Red Cross (TRC) regimen (2-2-2-0-1-1), healthy volunteers received 0.1 mL volumes of PCECV containing decreasing amounts of antigen. Subjects also received HRIG to evaluate potential interference with antibody production. Results indicated that when each 0.1 mL intradermal dose of PCECV contained antigen corresponding to 0.32 IU per intramuscular dose, every subject had titers above 0.5 IU/mL by day 14. These results confirm that the current World Health Organization (WHO) recommendations for vaccine potency (2.5 IU per intramuscular dose) are sufficient for use in the Thai Red Cross intradermal regimen. PMID:15917111

  3. Improved efficiency of the walnut somatic embryo gene transfer system.

    Science.gov (United States)

    McGranahan, G H; Leslie, C A; Uratsu, S L; Dandekar, A M

    1990-01-01

    AnAgrobacterium-mediated gene transfer system which relies on repetitive embryogenesis to regenerate transgenic walnut plants has been made more efficient by using a more virulent strain ofAgrobacterium and vectors containing genes for both kanamycin resistance and beta-glucuronidase (GUS) activity to facilitate early screening and selection. Two plasmids (pCGN7001 and pCGN7314) introduced individually into the disarmedAgrobacterium host strain EHA101 were used as inoculum. Embryos maintained on medium containing 100 mg/l kanamycin after co-cultivation produced more transformed secondary embryos than embryos maintained on kanamycin-free medium. Of the 186 GUS-positive secondary embryo lines identified, 70% were regenerated from 3 out of 16 primary embryos inoculated with EHA101/pCGN7314 and grown on kanamycin- containing medium, 28% from 4 out of 17 primary embryos inoculated with EHA101/ pCGN7001 and grown on kanamycin medium, and 2% from one out of 13 primary embryos inoculated with EHA101/pCGN7001 but not exposed to kanamycin. Because kanamycin inhibits but does not completely block new embryo formation in controls, identification of transformants formerly required repetitive selection on kanamycin for several months. Introduction of the GUS marker gene allowed positive identification of transformant secondary embryos as early as 5-6 weeks after inoculation. DNA analysis of a representative subset of lines (n=13) derived from secondary embryos confirmed transformation and provided evidence for multiple insertion events in single inoculated primary embryos. PMID:24226275

  4. Expression of connexins in human preimplantation embryos in vitro

    Directory of Open Access Journals (Sweden)

    Leese Henry J

    2004-06-01

    Full Text Available Abstract Intercellular communication via gap junctions is required to coordinate developmental processes in the mammalian embryo. We have investigated if the connexin (Cx isoforms known to form gap junctions in rodent preimplantation embryos are also expressed in human embryos, with the aim of identifying species differences in communication patterns in early development. Using a combination of polyA PCR and immunocytochemistry we have assessed the expression of Cx26, Cx31, Cx32, Cx40, Cx43 and Cx45 which are thought to be important in early rodent embryos. The results demonstrate that Cx31 and Cx43 are the main connexin isoforms expressed in human preimplantation embryos and that these isoforms are co-expressed in the blastocyst. Cx45 protein is expressed in the blastocyst but the protein may be translated from a generally low level of transcripts: which could only be detected in the PN to 4-cell embryos. Interestingly, Cx40, which is expressed by the extravillous trophoblast in the early human placenta, was not found to be expressed in the blastocyst trophectoderm from which this tissue develops. All of the connexin isoforms in human preimplantation embryos are also found in rodents pointing to a common regulation of these connexins in development of rodent and human early embryos and perhaps other species.

  5. Gibberellins control fruit patterning in Arabidopsis thaliana.

    Science.gov (United States)

    Arnaud, Nicolas; Girin, Thomas; Sorefan, Karim; Fuentes, Sara; Wood, Thomas A; Lawrenson, Tom; Sablowski, Robert; Østergaard, Lars

    2010-10-01

    The Arabidopsis basic helix-loop-helix (bHLH) proteins INDEHISCENT (IND) and ALCATRAZ (ALC) specify tissues required for fruit opening that have major roles in seed dispersal and plant domestication. Here, we show that synthesis of the phytohormone gibberellin is a direct and necessary target of IND, and that ALC interacts directly with DELLA repressors, which antagonize ALC function but are destabilized by gibberellin. Thus, the gibberellin/DELLA pathway has a key role in patterning the Arabidopsis fruit, and the interaction between DELLA and bHLH proteins, previously shown to connect gibberellin and light responses, is a versatile regulatory module also used in tissue patterning. PMID:20889713

  6. HYDROPONIC METHOD FOR CULTURING POPULATIONS OF ARABIDOPSIS

    Science.gov (United States)

    A plant life-cycle bioassay using Arabidopsis thaliana (L.) Heynh. was developed to detect potential chemical phytotoxicity. The bioassay requires large numbers of plants to maximize the probability of detecting deleterious effect and to avoid any bias that could occur if only a ...

  7. Rapid endocytosis is triggered upon imbibition in Arabidopsis seeds.

    Science.gov (United States)

    Pagnussat, Luciana; Burbach, Christian; Baluška, František; de la Canal, Laura

    2012-03-01

    During seed imbibition and embryo activation, rapid change from a metabolically resting state to the activation of diverse extracellular and/or membrane bound molecules is essential and, hence, endocytosis could be activated too. In fact, we have documented endocytic internalization of the membrane impermeable endocytic tracer FM4-64 already upon 30 min of imbibition of Arabidopsis seeds. This finding suggest that endocytosis is activated early during seed imbibition in Arabidopsis. Immunolocalization of rhamnogalacturonan-II (RG-II) complexed with boron showed that whereas this pectin is localized only in the cell walls of dry seed embryos, it starts to be intracellular once the imbibition started. Brefeldin A (BFA) exposure resulted in recruitment of the intracellular RG-II pectin complexes into the endocytic BFA-induced compartments, confirming the endocytic origin of the RG-II signal detected intracellularly. Finally, germination was significantly delayed when Arabidopsis seeds were germinated in the presence of inhibitors of endocytic pathways, suggesting that trafficking of extracellular molecules might play an important role in the overcome of germination. This work constitutes the first demonstration of endocytic processes during germination and opens new perspectives about the role of the extracellular matrix and membrane components in seed germination. PMID:22476454

  8. ABI3 controls embryo degreening through Mendel's I locus.

    Science.gov (United States)

    Delmas, Frédéric; Sankaranarayanan, Subramanian; Deb, Srijani; Widdup, Ellen; Bournonville, Céline; Bollier, Norbert; Northey, Julian G B; McCourt, Peter; Samuel, Marcus A

    2013-10-01

    Chlorophyll (chl) is essential for light capture and is the starting point that provides the energy for photosynthesis and thus plant growth. Obviously, for this reason, retention of the green chlorophyll pigment is considered a desirable crop trait. However, the presence of chlorophyll in mature seeds can be an undesirable trait that can affect seed maturation, seed oil quality, and meal quality. Occurrence of mature green seeds in oil crops such as canola and soybean due to unfavorable weather conditions during seed maturity is known to cause severe losses in revenue. One recently identified candidate that controls the chlorophyll degradation machinery is the stay-green gene, SGR1 that was mapped to Mendel's I locus responsible for cotyledon color (yellow versus green) in peas. A defect in SGR1 leads to leaf stay-green phenotypes in Arabidopsis and rice, but the role of SGR1 in seed degreening and the signaling machinery that converges on SGR1 have remained elusive. To decipher the gene regulatory network that controls degreening in Arabidopsis, we have used an embryo stay-green mutant to demonstrate that embryo degreening is achieved by the SGR family and that this whole process is regulated by the phytohormone abscisic acid (ABA) through ABSCISIC ACID INSENSITIVE 3 (ABI3); a B3 domain transcription factor that has a highly conserved and essential role in seed maturation, conferring desiccation tolerance. Misexpression of ABI3 was sufficient to rescue cold-induced green seed phenotype in Arabidopsis. This finding reveals a mechanistic role for ABI3 during seed degreening and thus targeting of this pathway could provide a solution to the green seed problem in various oil-seed crops. PMID:24043799

  9. Use of versapoint to refashion the cervical canal to overcome unusually difficult embryo transfers and improve in-vitro fertilization-embryo transfer outcome: A case series

    OpenAIRE

    Nalini Mahajan; Ila Gupta

    2011-01-01

    Background : Smooth atraumatic embryo transfer is paramount for the success of in-vitro fertilization (IVF). In difficult cases, cervical canal manipulation may be required. Aim : To see if surgical correction of the cervical canal or cervical canal refashioning could improve ease of embryo transfer. Setting : Private infertility and IVF hospital. Design : Prospective study. Materials and Methods : Patients: 11 women with failed 1-3 IVF cycles with history of extremely difficult embryo transf...

  10. Cryopreservation of embryos: an overview.

    Science.gov (United States)

    Engelmann, Florent

    2011-01-01

    Cryopreservation (liquid nitrogen, -196°C) is the only safe and cost-effective option for long-term -conservation of genetic resources of non-orthodox seed species. Cryopreservation protocols have been developed for various materials including seeds, dormant buds, cell suspensions, calli, apices, zygotic, and somatic embryos of numerous plant species. Zygotic embryos or embryonic axes of almost 100 different species and somatic embryos of almost 40 different species from both temperate and tropical climates, comprising crops, fruit, and forest trees as well as wild species, whose seeds displayed orthodox, intermediate, and recalcitrant storage characteristics, have been successfully cryopreserved. With zygotic embryos and embryonic axes, the desiccation technique has been used with the majority of the species tested, leading to highly variable survival and recovery after freezing, especially during earlier experiments. More recently, new cryopreservation techniques viz. encapsulation-dehydration and vitrification have been employed, leading to generally improved results. With somatic embryos, different cryopreservation methods have been used viz. desiccation, pre-growth-desiccation, encapsulation-dehydration, vitrification, encapsulation-vitrification, and droplet-vitrification. There are also a few examples of the utilisation of slow controlled freezing, which correspond to the earlier experiments performed with somatic embryos. The development and application of cryopreservation is significantly more advanced for somatic embryos, in comparison with zygotic embryos, mainly because of the different origin and characteristics of the species treated. In most cases, zygotic embryos originate from tropical, wild species, for which knowledge and techniques relevant to the development of cryopreservation protocols are limited, or even non-existent. By contrast, somatic embryos are generally produced from cultivated species, which have already been studied extensively

  11. Identification of transcription-factor genes expressed in the Arabidopsis female gametophyte

    Directory of Open Access Journals (Sweden)

    Kang Il-Ho

    2010-06-01

    Full Text Available Abstract Background In flowering plants, the female gametophyte is typically a seven-celled structure with four cell types: the egg cell, the central cell, the synergid cells, and the antipodal cells. These cells perform essential functions required for double fertilization and early seed development. Differentiation of these distinct cell types likely involves coordinated changes in gene expression regulated by transcription factors. Therefore, understanding female gametophyte cell differentiation and function will require dissection of the gene regulatory networks operating in each of the cell types. These efforts have been hampered because few transcription factor genes expressed in the female gametophyte have been identified. To identify such genes, we undertook a large-scale differential expression screen followed by promoter-fusion analysis to detect transcription-factor genes transcribed in the Arabidopsis female gametophyte. Results Using quantitative reverse-transcriptase PCR, we analyzed 1,482 Arabidopsis transcription-factor genes and identified 26 genes exhibiting reduced mRNA levels in determinate infertile 1 mutant ovaries, which lack female gametophytes, relative to ovaries containing female gametophytes. Spatial patterns of gene transcription within the mature female gametophyte were identified for 17 transcription-factor genes using promoter-fusion analysis. Of these, ten genes were predominantly expressed in a single cell type of the female gametophyte including the egg cell, central cell and the antipodal cells whereas the remaining seven genes were expressed in two or more cell types. After fertilization, 12 genes were transcriptionally active in the developing embryo and/or endosperm. Conclusions We have shown that our quantitative reverse-transcriptase PCR differential-expression screen is sufficiently sensitive to detect transcription-factor genes transcribed in the female gametophyte. Most of the genes identified in this

  12. Auxin control of embryo patterning

    NARCIS (Netherlands)

    Moller, B.K.; Weijers, D.

    2009-01-01

    Plants start their life as a single cell, which, during the process of embryogenesis, is transformed into a mature embryo with all organs necessary to support further growth and development. Therefore, each basic cell type is first specified in the early embryo, making this stage of development exce

  13. Improving production of Zebra Fish Embryos in the lab

    DEFF Research Database (Denmark)

    Thomsen, Jens Peter; Adu, Robert Ohene

    2011-01-01

    The utilization of fish embryos in toxicity testing of hazardous chemicals has recently been adopted in order to satisfy stricter rules and regulations related to using adult animals in toxicity testing. This paper presents optimising steps towards improving zebra fish embryo production in the...... within an hour of onset of light, an improvement over the 50-60 eggs produced in the previous work. This result demonstrates that with the right culture conditions and proper optimisation of procedure the required number of embryos needed for toxicity testing can be obtained....... laboratory. Culture conditions were maintained in the aquaria as stipulated in the OECD draft proposal for a new guideline on fish embryo tests. Furthermore, a sequence of steps were adopted and followed to improve upon previous work done in the lab in 2006. About 200 eggs were produced in one spawn trap...

  14. Non-surgical embryo transfer in pigs

    NARCIS (Netherlands)

    Hazeleger, W.

    1999-01-01

    Embryo transfer in pigs has been performed surgically for a long time. However, a less invasive, non-surgical, procedure of embryo transfer could be a valuable tool for research (to study embryo survival and embryo-uterus interactions) and practical applications (export, prevention of disease transm

  15. LEUNIG_HOMOLOG and LEUNIG Regulate Seed Mucilage Extrusion in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Minh Bui; Nathan Lim; Paja Sijacic; Zhongchi Liu

    2011-01-01

    LEUNIG(LUG)and LEUNIG_HOMOLOG(LUH)encode two closely related Arabidopsis proteins,belonging to the Gro/TLE family of transcriptional co-repressors.These two genes were previously shownto exhibit partially overlapping functions in embryo and flower development.In this report,the roleof both LUH and LUG on seed mucilage extrusion was examined.Seed mucilage extrusion occursafter the seeds are imbibed,serving as functional aid in seed hydration,germination,and dispersal.While luh-1 mutants exhibited strong defects in seed mucilage extrusion,lug-3 mutants exhibited aminor phenotype in mucilage extrusion.Further characterization indicates that luh-1 does not exhibitany obvious defect in seed epidermal cell differentiation,mucilage synthesis,or mucilage deposition,suggesting a specific role of LUH in mucilage extrusion.This seed mucilage phenotype of luh-1 isidentical to that of mucilage modified 2(mum2)mutants.MUM2 encodes a P-galactosidase required forthe modification of the mucilage.Quantitative reverse transcription polymerase chain reaction of RNAextracted from siliques detected a slight decrease of MUM2 mRNA in the luh-1 mutant compared to thewild type.Together,LUH and possibly LUG may specifically regulate mucilage extrusion by promotingthe expression of genes required for mucilage maturation.

  16. Analysis of Vascular Development in the hydra Sterol Biosynthetic Mutants of Arabidopsis

    Science.gov (United States)

    Pullen, Margaret; Clark, Nick; Zarinkamar, Fatemeh; Topping, Jennifer; Lindsey, Keith

    2010-01-01

    Background The control of vascular tissue development in plants is influenced by diverse hormonal signals, but their interactions during this process are not well understood. Wild-type sterol profiles are essential for growth, tissue patterning and signalling processes in plant development, and are required for regulated vascular patterning. Methodology/Principal Findings Here we investigate the roles of sterols in vascular tissue development, through an analysis of the Arabidopsis mutants hydra1 and fackel/hydra2, which are defective in the enzymes sterol isomerase and sterol C-14 reductase respectively. We show that defective vascular patterning in the shoot is associated with ectopic cell divisions. Expression of the auxin-regulated AtHB8 homeobox gene is disrupted in mutant embryos and seedlings, associated with variably incomplete vascular strand formation and duplication of the longitudinal axis. Misexpression of the auxin reporter proIAA2∶GUS and mislocalization of PIN proteins occurs in the mutants. Introduction of the ethylene-insensitive ein2 mutation partially rescues defective cell division, localization of PIN proteins, and vascular strand development. Conclusions The results support a model in which sterols are required for correct auxin and ethylene crosstalk to regulate PIN localization, auxin distribution and AtHB8 expression, necessary for correct vascular development. PMID:20808926

  17. Fluorescence-Activated Nucleolus Sorting in Arabidopsis.

    Science.gov (United States)

    Pontvianne, Frédéric; Boyer-Clavel, Myriam; Sáez-Vásquez, Julio

    2016-01-01

    Nucleolar isolation allows exhaustive characterization of the nucleolar content. Centrifugation-based protocols are not adapted to isolation of nucleoli directly from a plant tissue because of copurification of cellular debris. We describe here a method that allows the purification of nucleoli using fluorescent-activated cell sorting from Arabidopsis thaliana leaves. This approach requires the expression of a specific nucleolar protein such as fibrillarin fused to green fluorescent protein in planta. PMID:27576720

  18. In vivo photoacoustic imaging of mouse embryos

    Science.gov (United States)

    Laufer, Jan; Norris, Francesca; Cleary, Jon; Zhang, Edward; Treeby, Bradley; Cox, Ben; Johnson, Peter; Scambler, Pete; Lythgoe, Mark; Beard, Paul

    2012-06-01

    The ability to noninvasively image embryonic vascular anatomy in mouse models is an important requirement for characterizing the development of the normal cardiovascular system and malformations in the heart and vascular supply. Photoacoustic imaging, which can provide high resolution non invasive images of the vasculature based upon optical absorption by endogenous hemoglobin, is well suited to this application. In this study, photoacoustic images of mouse embryos were obtained ex vivo and in vivo. The images show intricate details of the embryonic vascular system to depths of up to 10 mm, which allowed whole embryos to be imaged in situ. To achieve this, an all-optical photoacoustic scanner and a novel time reversal image reconstruction algorithm, which provide deep tissue imaging capability while maintaining high spatial resolution and contrast were employed. This technology may find application as an imaging tool for preclinical embryo studies in developmental biology as well as more generally in preclinical and clinical medicine for studying pathologies characterized by changes in the vasculature.

  19. Pre implanted mouse embryos as model for uranium toxicology studies

    International Nuclear Information System (INIS)

    Full text: The search of 'in vitro' toxicology model that can predict toxicology effects 'in vivo' is a permanent challenge. A toxicology experimental model must to fill to certain requirements: to have a predictive character, an appropriate control to facilitate the interpretation of the data among the experimental groups, and to be able to control the independent variables that can interfere or modify the results that we are analyzing. The preimplantation embryos posses many advantages in this respect: they are a simple model that begins with the development of only one cell. The 'in vitro' model reproduces successfully the 'in vivo' situation. Due to the similarity that exists among the embryos of mammals during this period the model is practically valid for other species. The embryo is itself a stem cell, the toxicology effects are early observed in his clonal development and the physical-chemical parameters are easily controllable. The purpose of the exhibition is to explain the properties of the pre implanted embryo model for toxicology studies of uranium and to show our experimental results. The cultivation 'in vitro' of mouse embryos with uranylo nitrate demonstrated that the uranium causes from the 13 μgU/ml delay of development, decrease the number of cells per embryo and hipoploidy in the embryonic blastomere. (author)

  20. Toxicity of cryoprotectants on Prochilodus lineatus (Valenciennes, 1837 (curimba embryos in an experimental incubator (Characiformes: Prochilodontidae

    Directory of Open Access Journals (Sweden)

    Daniella A. J. Paula

    2014-12-01

    Full Text Available This paper investigated the effect of cryoprotectant substances on Prochilodus lineatus embryos in an experimental incubator. The prospective study applied combinations of polyvinyl alcohol, hydroxyethyl cellulose, gelatin and fetal bovine serum with dimethyl sulfoxide and ethylene glycol in a new experimental incubator. The morphology of embryos, larval viability and the efficiency of experimental incubators in maintaining the quality of embryos were evaluated. This study demonstrates the efficient association between hydroxyethylcellulose and dimethyl sulfoxide as greater viability (p<0.05 was found for embryos (72.9 ± 23.9%. It should also be noted the permeation of cryoprotectants in embryos through the changes found in chorion diameter, embryo diameter and embryo volume comparing the treatments versus control group (water (p<0.05, this results can help in future cryopreservation protocols. Although the temperature and oxygenation differed between the usual and experimental incubators (p<0.05, the results showed a high fertilization rate (79.6 ± 13.2% for experimental incubators (p<0.05 which is sufficient for the maintenance of embryos in a cryoprotective environment and effectively allows experimentation for long periods with cryoprotectant substances. Cryopreservation of fish embryos has not been accomplished yet and new approaches are required for understanding the permeability of teleost embryos, especially in Brazilian native species.

  1. In vitro embryo production in buffalo: current situation and future perspectives

    Directory of Open Access Journals (Sweden)

    B. Gasparrini

    2010-02-01

    Full Text Available In the last few years, there has been an increasing interest in the in vitro embryo production technologies for faster propagation of superior germplasm in buffalo, due to the low efficiency of multiple ovulation and embryo transfer programs. Early attempts to produce buffalo embryos in vitro have been made by using procedures that were proven effective in cattle. However, the acquisition of more specific information on oocyte and embryo culture requirements in vitro in this species has resulted in an improved efficiency over the years. Although the IVEP efficiency has enhanced, as indicated by competitive embryo yields, pregnancy rate and development to term are still poor. Furthermore, the optimization of embryo cryopreservation methods in this species is critical for the diffusion of ET procedures in the field. The present review intends to describe the state of the art of IVEP in buffalo species, emphasizing the advances achieved and the limitations still to overcome.

  2. Isolation-hypoxia and re-oxygenation of the pallial cavity of female Crepipatella dilatata during estuarine salinity changes requires increased glyoxylase activity and antioxidant metabolism to avoid oxidative damage to female tissues and developing embryos.

    Science.gov (United States)

    Cubillos, Víctor; Chaparro, Oscar; Segura, Cristian; Montory, Jaime; Cruces, Edgardo; Burritt, David

    2016-08-01

    The estuarine slipper limpet Crepipatella dilatata is a gastropod that can survive prolonged periods of low salinities (GST). As a result the levels of oxidative damage decline to basal levels within 24 h of reoxygenation. Thus the combination of isolation, a behavioural strategy, combined with encapsulation of embryos and a capacity to up regulate relatively rapidly the glyoxylase pathway and general antioxidant metabolism, play major roles in facilitating the survival of C. dilatata in the small estuaries of Southern Chile. PMID:27232979

  3. Arabidopsis in Wageningen

    OpenAIRE

    Koornneef, M

    2013-01-01

    Arabidopsis thaliana is the plant species that in the past 25 years has developed into the major model species in plant biology research. This was due to its properties such as short generation time, its small genome and its easiness to be transformed. Wageningen University has played an important role in the development of this model, based on interdisciplinary collaborations using genetics as a major tool to investigate aspects of physiology, development, plant-microbe interactions and evol...

  4. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of pathogens by the chicken... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  5. INHIBITING MAP KINASE ACTIVITY PREVENTS CALCIUM TRANSIENTS AND MITOSIS ENTRY IN EARLY SEA URCHIN EMBRYOS

    OpenAIRE

    Philipova, Rada; Larman, Mark G.; Leckie, Calum P.; Harrison, Patrick K.; Groigno, Laurence; Whitaker, Michael

    2005-01-01

    A transient calcium increase triggers nuclear envelope breakdown (mitosis entry) in sea urchin embryos. Cdk1/cyclin B kinase activation is also known to be required for mitosis entry. More recently MAP kinase activity has also been shown to increase during mitosis. In sea urchin embryos both kinases show a similar activation profile, peaking at the time of mitosis entry.

  6. 9 CFR 98.16 - The embryo collection unit.

    Science.gov (United States)

    2010-01-01

    ... breeding them (either natural breeding or artificial insemination). (b) Embryo collection area. The embryo... equipment used for artificial insemination or for collection, processing, or storage of embryos. The...

  7. Induction of autophagy improves embryo viability in cloned mouse embryos

    Science.gov (United States)

    Shen, XingHui; Zhang, Na; Wang, ZhenDong; Bai, GuangYu; Zheng, Zhong; Gu, YanLi; Wu, YanShuang; Liu, Hui; Zhou, DongJie; Lei, Lei

    2015-01-01

    Autophagy is an essential cellular mechanism that degrades cytoplasmic proteins and organelles to recycle their components. Moreover, autophagy is essential for preimplantation development in mammals. Here we show that autophagy is also important for reprogramming in somatic cell nuclear transfer (SCNT). Our data indicate that unlike fertilized oocytes, autophagy is not triggered in SCNT embryos during 6 hours of activation. Mechanistically, the inhibited autophagic induction during SCNT activation is due to the cytochalasin B (CB) caused depolymerization of actin filaments. In this study, we induced autophagy during SCNT activation by rapamycin and pp242, which could restore the expected level of autophagy and significantly enhance the development of SCNT embryos to the blastocyst stage when compared with the control (68.5% and 68.7% vs. 41.5%, P autophagy is important for development of SCNT embryos and inhibited autophagic induction during SCNT activation might be one of the serious causes of low efficiency of SCNT. PMID:26643778

  8. Feminists on the inalienability of human embryos.

    Science.gov (United States)

    McLeod, Carolyn; Baylis, Francoise

    2006-01-01

    The feminist literature against the commodification of embryos in human embryo research includes an argument to the effect that embryos are "intimately connected" to persons, or morally inalienable from them. We explore why embryos might be inalienable to persons and why feminists might find this view appealing. But, ultimately, as feminists, we reject this view because it is inconsistent with full respect for women's reproductive autonomy and with a feminist conception of persons as relational, embodied beings. Overall, feminists should avoid claims about embryos' being inalienable to persons in arguments for or against the commodification of human embryos. PMID:17111554

  9. Using giant scarlet runner bean embryos to uncover regulatory networks controlling suspensor gene activity

    Directory of Open Access Journals (Sweden)

    Kelli F. Henry

    2015-02-01

    Full Text Available One of the major unsolved issues in plant development is understanding the regulatory networks that control the differential gene activity that is required for the specification and development of the two major embryonic regions, the embryo proper and suspensor. Historically, the giant embryo of scarlet runner bean (SRB, Phaseolus coccineus, has been used as a model system to investigate the physiological events that occur early in embryogenesis – focusing on the question of what role the suspensor region plays. A major feature distinguishing SRB embryos from those of other plants is a highly enlarged suspensor containing at least 200 cells that synthesize growth regulators required for subsequent embryonic development. Recent studies have exploited the giant size of the SRB embryo to micro-dissect the embryo proper and suspensor regions in order to use genomics-based approaches to identify regulatory genes that may be involved in controlling suspensor and embryo proper differentiation, as well as the cellular processes that may be unique to each embryonic region. Here we review the current genomics resources that make SRB embryos a compelling model system for studying the early events required to program embryo development.

  10. Evidence for a disease-resistance pathway in rice similar to the NPR1-mediated signaling pathway in Arabidopsis.

    OpenAIRE

    Chern, M S; Fitzgerald, H A; YADAV, R. C.; Canlas, P E; Dong, X.; Ronald, P. C.

    2001-01-01

    The Arabidopsis NPR1/NIM1 gene is a key regulator of systemic acquired resistance (SAR). Over-expression of NPR1 leads to enhanced resistance in Arabidopsis. To investigate the role of NPR1 in monocots, we over-expressed the Arabidopsis NPR1 in rice and challenged the transgenic plants with Xanthomonas oryzae pv. oryzae (Xoo), the rice bacterial blight pathogen. The transgenic plants displayed enhanced resistance to Xoo. RNA blot hybridization indicates that enhanced resistance requires expre...

  11. Drosophila embryos lacking N-myristoyltransferase have multiple developmental defects.

    Science.gov (United States)

    Ntwasa, M; Aapies, S; Schiffmann, D A; Gay, N J

    2001-01-15

    Lipid modification of proteins by the addition of myristic acid to the N-terminal is important in a number of critical cellular processes, for example, signal transduction and the modulation of membrane association by myristoyl switches. Myristic acid is added to proteins by the enzyme N-myristoyltransferase (NMT) and in this paper we detail the effects on embryonic development of a null mutation in the Drosophila NMT gene. Mutant embryos display a range of phenotypes, including failures of head involution, dorsal closure, and germ-band retraction, morphogenetic processes that require cellular movements. Embryos with milder phenotypes have more specific defects in the central nervous system, including thinning of the ventral nerve chord and, in some embryos, specific scission at parasegment 10. Staining of mutant embryos with phalloidin shows that the mutant embryos have a disrupted actin cytoskeleton and abnormal cell morphology. These phenotypes are strikingly similar to those caused by genes involved in dynamic rearrangement of the actin cytoskeleton. For example the myristoylated nonreceptor tyrosine kinases Dsrc42A and Dsrc64B were shown recently to be key regulators of dorsal closure. In addition, analysis of cell death reveals widespread ectopic apoptosis. Our findings are consistent with the hypothesis that the myristoyl switches and signaling pathways characterized at the biochemical level have important functions in fundamental morphogenetic processes. PMID:11139338

  12. Phenotype classification of zebrafish embryos by supervised learning.

    Directory of Open Access Journals (Sweden)

    Nathalie Jeanray

    Full Text Available Zebrafish is increasingly used to assess biological properties of chemical substances and thus is becoming a specific tool for toxicological and pharmacological studies. The effects of chemical substances on embryo survival and development are generally evaluated manually through microscopic observation by an expert and documented by several typical photographs. Here, we present a methodology to automatically classify brightfield images of wildtype zebrafish embryos according to their defects by using an image analysis approach based on supervised machine learning. We show that, compared to manual classification, automatic classification results in 90 to 100% agreement with consensus voting of biological experts in nine out of eleven considered defects in 3 days old zebrafish larvae. Automation of the analysis and classification of zebrafish embryo pictures reduces the workload and time required for the biological expert and increases the reproducibility and objectivity of this classification.

  13. An Arabidopsis callose synthase

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole;

    2002-01-01

    unclear whether callose synthases can also produce cellulose and whether plant cellulose synthases may also produce beta-1,3-glucans. We describe here an Arabidopsis gene, AtGsl5, encoding a plasma membrane-localized protein homologous to yeast beta-1,3-glucan synthase whose expression partially......Beta-1,3-glucan polymers are major structural components of fungal cell walls, while cellulosic beta-1,4-glucan is the predominant polysaccharide in plant cell walls. Plant beta-1,3-glucan, called callose, is produced in pollen and in response to pathogen attack and wounding, but it has been...

  14. Microinjection wound assay and in vivo localization of epidermal wound response reporters in Drosophila embryos.

    Science.gov (United States)

    Juarez, Michelle T; Patterson, Rachel A; Li, Wilson; McGinnis, William

    2013-01-01

    The Drosophila embryo develops a robust epidermal layer that serves both to protect the internal cells from a harsh external environment as well as to maintain cellular homeostasis. Puncture injury with glass needles provides a direct method to trigger a rapid epidermal wound response that activates wound transcriptional reporters, which can be visualized by a localized reporter signal in living embryos or larvae. Puncture or laser injury also provides signals that promote the recruitment of hemocytes to the wound site. Surprisingly, severe (through and through) puncture injury in late stage embryos only rarely disrupts normal embryonic development, as greater than 90% of such wounded embryos survive to adulthood when embryos are injected in an oil medium that minimizes immediate leakage of hemolymph from puncture sites. The wound procedure does require micromanipulation of the Drosophila embryos, including manual alignment of the embryos on agar plates and transfer of the aligned embryos to microscope slides. The Drosophila epidermal wound response assay provides a quick system to test the genetic requirements of a variety of biological functions that promote wound healing, as well as a way to screen for potential chemical compounds that promote wound healing. The short life cycle and easy culturing routine make Drosophila a powerful model organism. Drosophila clean wound healing appears to coordinate the epidermal regenerative response, with the innate immune response, in ways that are still under investigation, which provides an excellent system to find conserved regulatory mechanisms common to Drosophila and mammalian epidermal wounding. PMID:24300796

  15. Improving embryo quality in assisted reproduction

    NARCIS (Netherlands)

    E. Mantikou

    2013-01-01

    The goal of this thesis was to improve embryo quality in assisted reproductive technologies by gaining more insight into human preimplantation embryo development and by improving in vitro culture conditions. To do so, we investigated an intriguing feature of the human preimplantation embryo, i.e. it

  16. Embryo growth in mature celery seeds.

    NARCIS (Netherlands)

    Toorn, van der P.

    1989-01-01

    Germination of celery seeds is slow, due to the need for embryo growth before radicle protrusion can occur. Germination rate was correlated with embryo growth rate. Celery seeds with different embryo growth rates were obtained with fluid density separation of a seed lot. Low density seeds germinated

  17. Free energy of multicomponent embryo formation

    OpenAIRE

    Kurasov, Victor

    2002-01-01

    An expression for the free energy of embryo formation is constructed and analyzed. The Gibbs dividing surfaces method is used to attain a coincidence between Laplace formula for critical embryo and integral definitions of concenterations inside the embryo. A global structure of free energy is analyzed and some useful properties are extracted.

  18. Transient overexpression of adh8a increases allyl alcohol toxicity in zebrafish embryos.

    Science.gov (United States)

    Klüver, Nils; Ortmann, Julia; Paschke, Heidrun; Renner, Patrick; Ritter, Axel P; Scholz, Stefan

    2014-01-01

    Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L). Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh) to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1) during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos). Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L). Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes involved in

  19. Preimplantation embryo-endometrial signalling

    NARCIS (Netherlands)

    Teklenburg, G.

    2010-01-01

    Recurrent pregnancy loss (RPL) is a common and distressing disorder. Chromosomal errors in the embryo are the single most common cause whereas uterine factors are invariably invoked to explain non-chromosomal miscarriages. These uterine factors are, however, poorly defined. The ability of a conceptu

  20. Photorepair mutants of Arabidopsis

    International Nuclear Information System (INIS)

    UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyces cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosophila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system

  1. Embryo technologies in the horse.

    Science.gov (United States)

    Squires, E L; Carnevale, E M; McCue, P M; Bruemmer, J E

    2003-01-01

    Recent studies demonstrated that zwitterionic buffers could be used for satisfactory storage of equine embryos at 5 degrees C. The success of freezing embryos is dependent upon size and stage of development. Morulae and blastocysts transfer. The majority of equine embryos are collected from single ovulating mares, as there is no commercially available product for superovulation in equine. However, pituitary extract, rich in FSH, can be used to increase embryo recovery three- to four-fold. Similar to human medicine, assisted reproductive techniques have been developed for the older, subfertile mare. Transfer of in vivo-matured oocytes from young, healthy mares into a recipient's oviduct results in a 70-80% pregnancy rate compared with a 30-40% pregnancy rate when the oocytes are from older, subfertile mares. This procedure can also be used to evaluate in vitro maturation systems. In vitro production of embryos is still quite difficult in the horse. However, intracytoplasmic sperm injection (ICSI) has been used to produce several foals. Cleavage rates of 60% and blastocyst rates of 30% have been reported after ICSI of in vitro-matured oocytes. Gamete intrafallopian tube transfer (GIFT) is a possible treatment for subfertile stallions. Transfer of in vivo-matured oocytes with 200,000 sperm into the oviduct of normal mares resulted in a pregnancy rate of 55-82%. Oocyte freezing is a technique that has proven difficult in most species. However, equine oocytes vitrified in a solution of ethylene glycol, DMSO, and Ficoll and loaded onto a cryoloop resulted in three pregnancies of 26 transfers and two live foals produced. Production of a cloned horse appears to be likely, as several cloned pregnancies have recently been produced. PMID:12499026

  2. A seed coat bedding assay to genetically explore in vitro how the endosperm controls seed germination in Arabidopsis thaliana

    OpenAIRE

    Lopez Molina, Luis; Lee, Keun Pyo

    2013-01-01

    The Arabidopsis endosperm consists of a single cell layer surrounding the mature embryo and playing an essential role to prevent the germination of dormant seeds or that of nondormant seeds irradiated by a far red (FR) light pulse. In order to further gain insight into the molecular genetic mechanisms underlying the germination repressive activity exerted by the endosperm, a "seed coat bedding" assay (SCBA) was devised. The SCBA is a dissection procedure physically separating seed coats and e...

  3. Twinning of amphibian embryos by centrifugation

    Science.gov (United States)

    Black, S. D.

    1984-01-01

    In the frog Xenopus laevis, the dorsal structures of the embryonic body axis normally derive from the side of the egg opposite the side of sperm entry. However, if the uncleaved egg is inclined at lg or centrifuged in an inclined position, this topographic relationship is overridden: the egg makes its dorsal axial structures according to its orientation in the gravitational/centrifugal field, irrespective of the position of sperm entry. Certain conditions of centrifugation cause eggs to develop into conjoined twins with two sets of axial structures. A detailed analysis of twinning provided some insight into experimental axis orientation. First, as with single-axis embryos, both axes in twins are oriented according to the direction of centrifugation. One axis forms at the centripetal side of the egg and the other forms at the centrifugal side, even when the side of sperm entry is normal to the centrifugal force vector. Second, if eggs are centrifuged to give twins, but are inclined at lg to prevent post-centrifugation endoplasmic redistributions, only single-axis embryos develop. Thus, a second redistribution is required for high-frequency secondary axis formation. This can be accomplished by lg (as in the single centrifugations) or by a second centrifugation directed along the egg's animal-vegetal axis.

  4. External mechanical cues trigger the establishment of the anterior-posterior axis in early mouse embryos.

    Science.gov (United States)

    Hiramatsu, Ryuji; Matsuoka, Toshiki; Kimura-Yoshida, Chiharu; Han, Sung-Woong; Mochida, Kyoko; Adachi, Taiji; Takayama, Shuichi; Matsuo, Isao

    2013-10-28

    Mouse anterior-posterior axis polarization is preceded by formation of the distal visceral endoderm (DVE) by unknown mechanisms. Here, we show by in vitro culturing of embryos immediately after implantation in microfabricated cavities that the external mechanical cues exerted on the embryo are crucial for DVE formation, as well as the elongated egg cylinder shape, without affecting embryo-intrinsic transcriptional programs except those involving DVE-specific genes. This implies that these developmental events immediately after implantation are not simply embryo-autonomous processes but require extrinsic factors from maternal tissues. Moreover, the mechanical forces induce a breach of the basement membrane barrier at the distal portion locally, and thereby the transmigrated epiblast cells emerge as the DVE cells. Thus, we propose that external mechanical forces exerted by the interaction between embryo and maternal uterine tissues directly control the location of DVE formation at the distal tip and consequently establish the mammalian primary body axis. PMID:24176640

  5. Muskmelon embryo rescue techniques using in vitro embryo culture.

    Science.gov (United States)

    Nuñez-Palenius, Hector Gordon; Ramírez-Malagón, Rafael; Ochoa-Alejo, Neftalí

    2011-01-01

    Among the major cucurbit vegetables, melon (Cucumis melo) has one of the greatest polymorphic fruit types and botanical varieties. Some melon fruits have excellent aroma, variety of flesh colors, deeper flavor, and more juice compared to other cucurbits. Despite numerous available melon cultivars, some of them are exceedingly susceptible to several diseases. The genetic background carrying the genes for tolerance and/or resistance for those diseases is found in wild melon landraces. Unfortunately, the commercial melon varieties are not able to produce viable hybrids when crossed with their wild melon counterparts. Plant tissue culture techniques are needed to surpass those genetic barriers. In vitro melon embryo rescue has played a main role to obtain viable hybrids originated from commercial versus wild melon crosses. In this chapter, an efficient and simple embryo rescue melon protocol is thoroughly described. PMID:21207265

  6. Self-consuming innate immunity in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Mundy, John; Petersen, Morten

    2009-01-01

    . However, it has been unclear by which molecular mechanisms plants execute PCD during innate immune responses. We recently examined HR PCD in autophagy-deficient Arabidopsis knockout mutants (atg) and find that PCD conditioned by one class of plant innate immune receptors is suppressed in atg mutants....... Intriguingly, HR triggered by another class of immune receptors with different genetic requirements is not compromised, indicating that only a specific subset of immune receptors engage the autophagy pathway for HR execution. Thus, our work provides a primary example of autophagic cell death associated with...... innate immune responses in eukaryotes as well as of prodeath functions for the autophagy pathway in plants....

  7. Transgenic Arabidopsis Gene Expression System

    Science.gov (United States)

    Ferl, Robert; Paul, Anna-Lisa

    2009-01-01

    The Transgenic Arabidopsis Gene Expression System (TAGES) investigation is one in a pair of investigations that use the Advanced Biological Research System (ABRS) facility. TAGES uses Arabidopsis thaliana, thale cress, with sensor promoter-reporter gene constructs that render the plants as biomonitors (an organism used to determine the quality of the surrounding environment) of their environment using real-time nondestructive Green Fluorescent Protein (GFP) imagery and traditional postflight analyses.

  8. Hyaluronan and hyaluronidase, which is better for embryo development?

    Science.gov (United States)

    Marei, Waleed F A; Raheem, Kabir A; Salavati, Mazdak; Tremaine, Tina; Khalid, Muhammad; Fouladi-Nashta, Ali A

    2016-09-01

    Our aim was to examine size-specific effects of Hyaluronan (HA) on preimplantation embryo development. We investigated the effects of Hyalovet (HA, 500-750 kDa; the size produced by HA synthase-3, which is abundant in the oviduct), or HA treated with Hyaluronidase-2 (Hyal2; also expressed in the oviduct that breaks down HA into 20 kDa fragments). In experiment 1 (in vivo), oviducts of synchronized and superovulated ewes (n = 20) were surgically exposed on Day 2 post-mating, ligated, and infused with either Hyalovet, Hyalovet + Hyal2, Hyal2, or PBS (control). Ewes were killed 5 days later for recovery of embryos and oviductal epithelial cells (OEC). Blastocyst rates were significantly higher in Hyal2 and Hyalovet + Hyal2 oviducts. Hyaluronidase-2 infusion resulted in higher blastocyst cell numbers and hatching rates. This was associated with increased HSP70 expression in OEC. In contrast, Hyalovet resulted in the lowest development to blastocyst stage and lowest hatching rates, and decreased IGF2 and IGFBP2 expression in OEC. IGF1 and IL1α expression were not affected. In experiment 2, to rule out indirect effects of oviductal factors, ovine embryos were produced and cultured with the same treatments in vitro from Day 2 to 8. Hyaluronidase-2, but not Hyalovet, enhanced blastocyst formation and reduced inner cell mass apoptosis. Hyalovet inhibited hatching. In conclusion, the presence of large-size HA (500-750 kDa) in the vicinity of developing embryos appears to disturb the oviductal environment and embryo development in vivo and in vitro. In contrast, we show evidence that breakdown of HA into smaller fragments is required to maximize embryo development and blastocyst quality. PMID:27091071

  9. Aberrant DNA methylation in cloned ovine embryos

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; HOU Jian; LEI TingHua; BAI JiaHua; GUAN Hong; AN XiaoRong

    2008-01-01

    By using the approach of immunofluorescence staining with an antibody against 5-methylcytosine (5MeC), the present study detected the DNA methylation patterns of cloned ovine embryos. The em-bryos derived from in vitro fertilization were also examined for reference purpose. The results showed that: (1) during the pre-implantation development, cloned embryos displayed a similar demethylation profile to the fertilized embryos; that is, the methylation level decreased to the lowest at 8-cell stage, and then increased again at morulae stage. However, methylation level was obviously higher in cloned embryos than in stage-matched fertilized embryos, especially at 8-cell stage and afterwards; (2) at blastocyst stage, the methylation pattern in cloned embryos was different from that in fertilized em-bryos. In cloned blastocyst, inner cell mass (ICM) exhibited a comparable level to trophectoderm cells (TE), while in in-vitro fertilized blastocyst the methylation level of ICM was lower than that of TE, which is not consistent with that reported by other authors. These results indicate that DNA methylation is abnormally reprogrammed in cloned embryos, implying that aberrant DNA methylation reprogramming may be one of the factors causing cloned embryos developmental failure.

  10. Determination of gene expression patterns using high-throughput RNA in situ hybridizaion to whole-mount Drosophila embryos

    Energy Technology Data Exchange (ETDEWEB)

    Weiszmann, R.; Hammonds, A.S.; Celniker, S.E.

    2009-04-09

    We describe a high-throughput protocol for RNA in situ hybridization (ISH) to Drosophila embryos in a 96-well format. cDNA or genomic DNA templates are amplified by PCR and then digoxigenin-labeled ribonucleotides are incorporated into antisense RNA probes by in vitro transcription. The quality of each probe is evaluated before ISH using a RNA probe quantification (dot blot) assay. RNA probes are hybridized to fixed, mixed-staged Drosophila embryos in 96-well plates. The resulting stained embryos can be examined and photographed immediately or stored at 4oC for later analysis. Starting with fixed, staged embryos, the protocol takes 6 d from probe template production through hybridization. Preparation of fixed embryos requires a minimum of 2 weeks to collect embryos representing all stages. The method has been used to determine the expression patterns of over 6,000 genes throughout embryogenesis.

  11. In vitro embryo outgrowth is a bioassay of in vivo embryo implantation and development

    OpenAIRE

    Binder, Natalie K.; Hannan, Natalie J; David K. Gardner

    2015-01-01

    Objective: To determine the efficacy of embryo outgrowth on fibronectin as a low cost, high throughput alternative to embryo transfer to model embryo attachment and the initial stages of implantation. Methods: Following in vitro embryo culture, embryo quality was assessed via embryo transfer or embryo outgrowth with metabolic assessment. Results: This study shows that blastocysts attach to fibronectin at the same rate that they implant in vivo, and that the carbohydrate utilisation of e...

  12. Nucleolar remodeling in nuclear transfer embryos

    DEFF Research Database (Denmark)

    Laurincik, Jozef; Maddox-Hyttel, Poul

    2007-01-01

    nucleoli are not apparent until the 5th cell cycle, whereas in somatic cell nuclear transfer embryos the functional nucleoli emerge already during the 3rd cell cycle. Intergeneric reconstructed embryos produced by the fusion of bovine differentiated somatic cell to a nonactivated ovine cytoplast fail...... the developmental potential of embryos originating from varied nuclear transfer protocols. In bovine in vivo developed embryos, functional ribosome-synthesizing nucleoli become structurally distinct toward the end of the 4th post-fertilization cell cycle. In embryonic cell nuclear transfer embryos, fully developed...... is completed toward the end of the 4th cell cycle. A substantial proportion of bovine embryos produced by nuclear transfer of embryonic or somatic cells to bovine ooplasts display aberrations in protein localization in one or more blastomers. This information is indicative of underlying aberrations in genomic...

  13. Genetics of Lipid-Storage Management in Caenorhabditis elegans Embryos.

    Science.gov (United States)

    Schmökel, Verena; Memar, Nadin; Wiekenberg, Anne; Trotzmüller, Martin; Schnabel, Ralf; Döring, Frank

    2016-03-01

    Lipids play a pivotal role in embryogenesis as structural components of cellular membranes, as a source of energy, and as signaling molecules. On the basis of a collection of temperature-sensitive embryonic lethal mutants, a systematic database search, and a subsequent microscopic analysis of >300 interference RNA (RNAi)-treated/mutant worms, we identified a couple of evolutionary conserved genes associated with lipid storage in Caenorhabditis elegans embryos. The genes include cpl-1 (cathepsin L-like cysteine protease), ccz-1 (guanine nucleotide exchange factor subunit), and asm-3 (acid sphingomyelinase), which is closely related to the human Niemann-Pick disease-causing gene SMPD1. The respective mutant embryos accumulate enlarged droplets of neutral lipids (cpl-1) and yolk-containing lipid droplets (ccz-1) or have larger genuine lipid droplets (asm-3). The asm-3 mutant embryos additionally showed an enhanced resistance against C band ultraviolet (UV-C) light. Herein we propose that cpl-1, ccz-1, and asm-3 are genes required for the processing of lipid-containing droplets in C. elegans embryos. Owing to the high levels of conservation, the identified genes are also useful in studies of embryonic lipid storage in other organisms. PMID:26773047

  14. Phospholipid transfer activities in toad oocytes and developing embryos

    International Nuclear Information System (INIS)

    The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14C-labeled phospholipids and 3H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth

  15. Sperm is epigenetically programmed to regulate gene transcription in embryos.

    Science.gov (United States)

    Teperek, Marta; Simeone, Angela; Gaggioli, Vincent; Miyamoto, Kei; Allen, George E; Erkek, Serap; Kwon, Taejoon; Marcotte, Edward M; Zegerman, Philip; Bradshaw, Charles R; Peters, Antoine H F M; Gurdon, John B; Jullien, Jerome

    2016-08-01

    For a long time, it has been assumed that the only role of sperm at fertilization is to introduce the male genome into the egg. Recently, ideas have emerged that the epigenetic state of the sperm nucleus could influence transcription in the embryo. However, conflicting reports have challenged the existence of epigenetic marks on sperm genes, and there are no functional tests supporting the role of sperm epigenetic marking on embryonic gene expression. Here, we show that sperm is epigenetically programmed to regulate embryonic gene expression. By comparing the development of sperm- and spermatid-derived frog embryos, we show that the programming of sperm for successful development relates to its ability to regulate transcription of a set of developmentally important genes. During spermatid maturation into sperm, these genes lose H3K4me2/3 and retain H3K27me3 marks. Experimental removal of these epigenetic marks at fertilization de-regulates gene expression in the resulting embryos in a paternal chromatin-dependent manner. This demonstrates that epigenetic instructions delivered by the sperm at fertilization are required for correct regulation of gene expression in the future embryos. The epigenetic mechanisms of developmental programming revealed here are likely to relate to the mechanisms involved in transgenerational transmission of acquired traits. Understanding how parental experience can influence development of the progeny has broad potential for improving human health. PMID:27034506

  16. Effects of VLA-4 antagonists in rat whole embryo culture.

    Science.gov (United States)

    Spence S; Vetter C; Hagmann WK; Van Riper G; Williams H; Mumford RA; Lanza TJ; Lin LS; Schmidt JA

    2002-01-01

    BACKGROUND: Pharmacological antagonism of VLA-4 (Very Late Antigen 4, alpha(4)beta(1) integrin) has become an attractive target for the treatment of predominantly eosinophil mediated disease states such as asthma, allergic rhinitis, multiple sclerosis, rheumatoid arthritis, diabetes, and inflammatory bowel disease. Gene knockouts of the alpha(4)-integrin subunit of VLA-4 or its cell surface ligand, VCAM-1, however, have been shown to result in embryo-lethality in homozygous null mice due to defects in chorio-allantoic or epi-myocardial fusion. Although gene knockout phenotypes are not always manifested by pharmacological antagonism, those studies suggested that VLA-4 antagonists might cause embryo-lethality or drug-induced malformations.METHODS: To test these concepts, early neurulating rat embryos were cultured by the methods of New ('78) after intra-coelomic microinjection of a VLA-4 blocking antibody or in the presence of small molecule VLA-4 antagonists.RESULTS: Defects in chorio-allantoic fusion were induced after microinjection of VLA4 blocking antibody and after continuous exposure to small molecule antagonists. In a minority of affected embryos chorio-allantoic fusion was completely blocked whereas the majority of affected embryos had only superficial chorio-allantoic fusion and the allantois was enlarged and edematous. Although the allantoic mesoderm covered the trophoblasts of the chorionic plate and contained blood vessels there was only minimal invasion of the trophoblasts by the allantoic mesoderm. The lowest observed effect level generally correlated with the IC(approximately 95), as determined in 90% plasma.DISCUSSION: Based on these data, VLA-4 antagonism might represent a significant risk to the developing embryo/fetus. In vitro exposure, however, is "constant" and does not take into account the elimination phase of these xenobiotics in vivo. Given the high concentrations required to elicit an effect, therapeutic blood levels in vivo may be several

  17. Auxin distribution and transport during embryogenesis and seed germi-nation of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Auxin distribution during embryogenesis and seed germination were studied with transgenic Arabidopsis plants expressing GUS gene driven by a synthetic DR5 promoter, an auxin responsive promoter. The results showed that GUS activity is higher in ends of hypophysis and cotyledon primordia of heart-, torpedo- and cotyledon-stage embryos, leaf tip area, lateral root primordia, root apex and cotyledon of young seedlings.And GUS accumulated in root apex of the seedlings grown on auxin transport inhibitor containing media.All these suggested that above-mentioned part of the organs and tissues have a higher level of auxin, and auxin polar transport inhibitor could cause the accumulation of auxin in root apex. And auxin transport inhibitor also resulted in aberration of Arabidopsis leaf pattern formation, root gravitropism and elongation.

  18. Outcome in children from cryopreserved embryos.

    OpenAIRE

    Sutcliffe, A. G.; D'Souza, S W; Cadman, J; Richards, B.; McKinlay, I A; Lieberman, B.

    1995-01-01

    A cohort of 91 children from cryopreserved embryos and 83 control children who were conceived normally had their development assessed using the Griffiths's scales of mental development. The controls (81 singletons and two twins) of a similar age, sex, and social class were selected from siblings, cousins, and peers of the cryopreserved embryo group (68 singleton, 20 twins, and three triplets). Children from cryopreserved embryos had a lower mean birth weight and mean gestational age and a hig...

  19. Moral qualms, future persons, and embryo research

    OpenAIRE

    Shaw, D. M.

    2008-01-01

    Many people have moral qualms about embryo research, feeling that embryos must deserve some kind of protection, if not so much as is afforded to persons. This paper will show that these qualms serve to camouflage motives that are really prudential, at the cost of also obscuring the real ethical issues at play in the debate concerning embryo research and therapeutic cloning. This in turn leads to fallacious use of the Actions/Omissions Distinction and ultimately neglects the duties that we hav...

  20. Research on human embryos--a justification.

    OpenAIRE

    J. Brown

    1986-01-01

    The philosophical debate surrounding the moral status of the embryo has reached the public arena. The author of this paper examines some of the common arguments against embryo experimentation, including an influential article by Professor Ian Kennedy. He concludes that these arguments do not succeed in demonstrating that the intentional creation of embryos for research purposes is wrong, unless they also succeed in demonstrating that contemporary liberal abortion laws are also wrong. The auth...

  1. Rhamnolipids elicit defense responses and induce disease resistance against biotrophic, hemibiotrophic, and necrotrophic pathogens that require different signaling pathways in Arabidopsis and highlight a central role for salicylic acid.

    Science.gov (United States)

    Sanchez, Lisa; Courteaux, Barbara; Hubert, Jane; Kauffmann, Serge; Renault, Jean-Hugues; Clément, Christophe; Baillieul, Fabienne; Dorey, Stéphan

    2012-11-01

    Plant resistance to phytopathogenic microorganisms mainly relies on the activation of an innate immune response usually launched after recognition by the plant cells of microbe-associated molecular patterns. The plant hormones, salicylic acid (SA), jasmonic acid, and ethylene have emerged as key players in the signaling networks involved in plant immunity. Rhamnolipids (RLs) are glycolipids produced by bacteria and are involved in surface motility and biofilm development. Here we report that RLs trigger an immune response in Arabidopsis (Arabidopsis thaliana) characterized by signaling molecules accumulation and defense gene activation. This immune response participates to resistance against the hemibiotrophic bacterium Pseudomonas syringae pv tomato, the biotrophic oomycete Hyaloperonospora arabidopsidis, and the necrotrophic fungus Botrytis cinerea. We show that RL-mediated resistance involves different signaling pathways that depend on the type of pathogen. Ethylene is involved in RL-induced resistance to H. arabidopsidis and to P. syringae pv tomato whereas jasmonic acid is essential for the resistance to B. cinerea. SA participates to the restriction of all pathogens. We also show evidence that SA-dependent plant defenses are potentiated by RLs following challenge by B. cinerea or P. syringae pv tomato. These results highlight a central role for SA in RL-mediated resistance. In addition to the activation of plant defense responses, antimicrobial properties of RLs are thought to participate in the protection against the fungus and the oomycete. Our data highlight the intricate mechanisms involved in plant protection triggered by a new type of molecule that can be perceived by plant cells and that can also act directly onto pathogens. PMID:22968829

  2. The Function of the Early Trichomes Gene in Arabidopsis and Maize.

    Energy Technology Data Exchange (ETDEWEB)

    Scott Poethig

    2011-12-05

    Lateral organ polarity in Arabidopsis is regulated by antagonistic interactions between genes that promote either adaxial or abaxial identity, but the molecular basis of this interaction is largely unknown. We show that the adaxial regulator ASYMMETRIC LEAVES2 (AS2) is a direct target of the abaxial regulator KANADI1 (KAN1), and that KAN1 represses the transcription of AS2 in abaxial cells. Mutation of a single nucleotide in a KAN1 binding site in the AS2 promoter causes AS2 to be ectopically expressed in abaxial cells, resulting in a dominant, adaxialized phenotype. We also show that the abaxial expression of KAN1 is mediated directly or indirectly by AS2. These results demonstrate that KAN1 acts as a transcriptional repressor and that mutually repressive interactions between KAN1 and AS2 contribute to the establishment of adaxial-abaxial polarity in plants. A screen for mutations that affect the expression of a GFP reporter for KANADI2 produced mutations in two genes, CENTER CITY (CCT) and GRAND CENTRAL (GCT). Mutations in GCT and CCT delay the specification of central and peripheral identity and the globular-to-heart transition, but have little or no effect on the initial growth rate of the embryo. Mutant embryos eventually recover and undergo relatively normal patterning, albeit at an inappropriate size. GCT and CCT were identified as the Arabidopsis orthologs of MED12 and MED13--evolutionarily conserved proteins that act in association with the Mediator complex to negatively regulate transcription. The predicted function of these proteins combined with the effect of gct and cct on embryo development suggests that MED12 and MED13 regulate pattern formation during Arabidopsis embryogenesis by transiently repressing a transcriptional program that interferes with this process. Their mutant phenotype reveals the existence of a previously unknown temporal regulatory mechanism in plant embryogenesis.

  3. Unique Features of the m6A Methylome in Arabidopsis thaliana

    OpenAIRE

    Luo, Guan-Zheng; MacQueen, Alice; Zheng, Guanqun; Duan, Hongchao; Dore, Louis C; Lu, Zhike; LIU Jun; Chen, Kai; Jia, Guifang; Bergelson, Joy; He, Chuan

    2014-01-01

    Recent discoveries of reversible N 6-methyladenosine (m6A) methylation on messenger RNA (mRNA) and mapping of m6A methylomes in mammals and yeast have revealed potential regulatory functions of this RNA modification. In plants, defects in m6A methyltransferase cause an embryo-lethal phenotype, suggesting a critical role of m6A in plant development. Here, we profile m6A transcriptome-wide in two accessions of Arabidopsis thaliana and reveal that m6A is a highly conserved modification of mRNA i...

  4. Radionuclide Exposure of the Embryo/Fetus

    International Nuclear Information System (INIS)

    This report addresses the determination of radiation dose to the embryo (the conceptus from fertilisation to organogenesis) and the fetus (post-organogenesis to birth) from radionuclides that are present in the woman before her pregnancy or that enter her during her pregnancy. This exposure may be via nuclear medicine procedures, occupational exposures or environmental sources that may affect the general population. The effects of radiation on the embryo/fetus are greatly influenced by the dependence on stage of gestation, which affects the transfer of radioactivity from the pregnant woman to the fetoplacental system, the distribution of the activity and the developmental effects of the resulting radiation absorbed doses. A chapter is therefore devoted to a detailed discussion of development of the embryo/fetus through the stages of pre-implantation, implantation and post-implantation development and the fetal period. To an non-expert the anatomical detail and nomenclature are rather difficult, but diagrams are clear and well labelled and a useful glossary of terms is provided. Mechanisms of maternal-fetal exchange and the effects of the maternal organs and placenta as external sources of radiation are then discussed, though it is stressed here - as throughout the report - that most information about the distribution and retention of materials during pregnancy has been obtained from studies in experimental animals. Extrapolation of animal data to humans is difficult and potentially inaccurate. The effects of prenatal irradiation are categorised as early, delayed and late effects. Early effects are further divided into the pre-implantation period (blastogenesis), period of organ formation (organogenesis) and period of the fetus (fetogenesis). Chapters 7 and 8 deal with compartmental modelling, dosimetry and estimation of embryo/fetus dose in radiation protection practice. The ICRP and MIRD methodologies are discussed, both of which differentiate source and target

  5. Evaluation of 14 Organic Solvents and Carriers for Screening Applications in Zebrafish Embryos and Larvae

    OpenAIRE

    Maes, Jan; Verlooy, Lien; Buenafe, Olivia E.; de Witte, Peter A. M.; Esguerra, Camila V.; Crawford, Alexander D.

    2012-01-01

    Zebrafish are rapidly growing in popularity as an in vivo model system for chemical genetics, drug discovery, and toxicology, and more recently also for natural product discovery. Experiments involving the pharmacological evaluation of small molecules or natural product extracts in zebrafish bioassays require the effective delivery of these compounds to embryos and larvae. While most samples to be screened are first solubilized in dimethyl sulfoxide (DMSO), which is then diluted in the embryo...

  6. Effects of Multimodal Analgesia on the Success of Mouse Embryo Transfer Surgery

    OpenAIRE

    Parker, John M.; Austin, Jamie; Wilkerson, James; Carbone, Larry

    2011-01-01

    Multimodal analgesia is promoted as the best practice pain management for invasive animal research procedures. Universal acceptance and incorporation of multimodal analgesia requires assessing potential effects on study outcome. The focus of this study was to assess effects on embryo survival after multimodal analgesia comprising an opioid and nonsteroidal antiinflammatory drug (NSAID) compared with opioid-only analgesia during embryo transfer procedures in transgenic mouse production. Mice w...

  7. Using giant scarlet runner bean embryos to uncover regulatory networks controlling suspensor gene activity

    OpenAIRE

    Henry, Kelli F.; Goldberg, Robert B.

    2015-01-01

    One of the major unsolved issues in plant development is understanding the regulatory networks that control the differential gene activity that is required for the specification and development of the two major embryonic regions, the embryo proper and suspensor. Historically, the giant embryo of scarlet runner bean (SRB), Phaseolus coccineus, has been used as a model system to investigate the physiological events that occur early in embryogenesis—focusing on the question of what role the susp...

  8. Klf5 regulates lineage formation in the pre-implantation mouse embryo

    OpenAIRE

    Lin, Suh-Chin J.; Wani, Maqsood A.; Whitsett, Jeffrey A.; Wells, James M.

    2010-01-01

    Kruppel-like transcription factors (Klfs) are essential for the induction and maintenance of pluripotency of embryonic stem cells (ESCs), yet little is known about their roles in establishing the three lineages of the pre-implantation embryo. Here, we show that Klf5 is required for the formation of the trophectoderm (TE) and the inner cell mass (ICM), and for repressing primitive endoderm (PE) development. Although cell polarity appeared normal, Klf5 mutant embryos arrested at the blastocyst ...

  9. Weedy Adaptation in Setaria spp.: VIII. Structure of Setaria faberi Seed, Caryopsis and Embryo Germination

    OpenAIRE

    Haar, Milt; van Aelst, Adriaan; Dekker, Jack

    2014-01-01

    Giant foxtail (Setaria faberi) seeds differ in requirements for germination. Variable germinability arises during seed development under the influence of genotype, environment and parent plant. Giant foxtail seed germination has been shown to be regulated by independent asynchronous or dependent synchronous action of seed structures. To gain better insight into the process, germination was divided into axis specific embryo growth categories or states. Three states were defined for each embryo...

  10. Pollination and embryo development in Brassica rapa L. in microgravity

    Science.gov (United States)

    Kuang, A.; Popova, A.; Xiao, Y.; Musgrave, M. E.

    2000-01-01

    Plant reproduction under spaceflight conditions has been problematic in the past. In order to determine what aspect of reproductive development is affected by microgravity, we studied pollination and embryo development in Brassica rapa L. during 16 d in microgravity on the space shuttle (STS-87). Brassica is self-incompatible and requires mechanical transfer of pollen. Short-duration access to microgravity during parabolic flights on the KC-135A aircraft was used initially to confirm that equal numbers of pollen grains could be collected and transferred in the absence of gravity. Brassica was grown in the Plant Growth Facility flight hardware as follows. Three chambers each contained six plants that were 13 d old at launch. As these plants flowered, thin colored tape was used to indicate the date of hand pollination, resulting in silique populations aged 8-15 d postpollination at the end of the 16-d mission. The remaining three chambers contained dry seeds that germinated on orbit to produce 14-d-old plants just beginning to flower at the time of landing. Pollen produced by these plants had comparable viability (93%) with that produced in the 2-d-delayed ground control. Matched-age siliques yielded embryos of equivalent developmental stage in the spaceflight and ground control treatments. Carbohydrate and protein storage reserves in the embryos, assessed by cytochemical localization, were also comparable. In the spaceflight material, growth and development by embryos rescued from siliques 15 d after pollination lagged behind the ground controls by 12 d; however, in the subsequent generation, no differences between the two treatments were found. The results demonstrate that while no stage of reproductive development in Brassica is absolutely dependent upon gravity, lower embryo quality may result following development in microgravity.

  11. Possible effect from shear stress on maturation of somatic embryos of Norway spruce (Picea abies).

    Science.gov (United States)

    Sun, Hong; Aidun, Cyrus K; Egertsdotter, Ulrika

    2011-05-01

    Somatic embryogenesis is the only method with the potential for industrial scale clonal propagation of conifers. Implementation of the method has so far been hampered by the extensive manual labor required for development of the somatic embryos into plants. The utilization of bioreactors is limited since the somatic embryos will not mature and germinate under liquid culture conditions. The negative effect on mature embryo yields from liquid culture conditions has been previously described. We have described the negative effects of shear stress on the development of early stage somatic embryos (proembryogenic masses; PEMs) at shear stresses of 0.086 and 0.14 N/m(2). In the present study, additional flow rates were studied to determine the effects of shear stress at lower rates resembling shear stress in a suspension culture flask. The results showed that shear stress at 0.009, 0.014, and 0.029 N/m(2) inhibited the PEM expansions comparing with the control group without shear stress. This study also provides validation for the cross-correlation method previously developed to show the effect of shear stress on early stage embryo suspensor cell formation and polarization. Furthermore, shear stress was shown to positively affect the uptake of water into the cells. The results indicate that the plasmolyzing effect from macromolecules added to liquid culture medium to stimulate maturation of the embryos are affected by liquid culture conditions and thus can affect the conversion of PEMs into mature somatic embryos. PMID:21449024

  12. Arabidopsis Growth Simulation Using Image Processing Technology

    Directory of Open Access Journals (Sweden)

    Junmei Zhang

    2014-01-01

    Full Text Available This paper aims to provide a method to represent the virtual Arabidopsis plant at each growth stage. It includes simulating the shape and providing growth parameters. The shape is described with elliptic Fourier descriptors. First, the plant is segmented from the background with the chromatic coordinates. With the segmentation result, the outer boundary series are obtained by using boundary tracking algorithm. The elliptic Fourier analysis is then carried out to extract the coefficients of the contour. The coefficients require less storage than the original contour points and can be used to simulate the shape of the plant. The growth parameters include total area and the number of leaves of the plant. The total area is obtained with the number of the plant pixels and the image calibration result. The number of leaves is derived by detecting the apex of each leaf. It is achieved by using wavelet transform to identify the local maximum of the distance signal between the contour points and the region centroid. Experiment result shows that this method can record the growth stage of Arabidopsis plant with fewer data and provide a visual platform for plant growth research.

  13. Embryo development in dairy cattle.

    Science.gov (United States)

    Lonergan, Pat; Fair, Trudee; Forde, Niamh; Rizos, Dimitrios

    2016-07-01

    During the past 50 years, the fertility of high-producing lactating dairy cows has decreased, associated with intensive selection for increased milk production. The physiological and metabolic changes associated with high milk production, including decreased (glucose, insulin, IGF-I) or increased (nonesterified fatty acids, ketone bodies) concentrations of circulating metabolites during nutrient partitioning associated with negative energy balance as well as uterine and nonuterine diseases have been linked with poor reproductive efficiency. Fertilization is typically above 80% and does not seem to be the principal factor responsible for the low fertility in dairy cows. However, early embryonic development is compromised in high-producing dairy cows, as observed by most embryonic losses occurring during the first 2 weeks after fertilization and may be linked to compromised oocyte quality due to a poor follicular microenvironment, suboptimal reproductive tract environment for the embryo, and/or inadequate maternal-embryonic communication. These and other factors related to embryo development will be discussed. PMID:27158131

  14. Virulence of Campylobacter jejuni for chicken embryos.

    OpenAIRE

    Mahajan, S; Rodgers, F G

    1989-01-01

    The pathogenicity of Campylobacter jejuni was examined in chicken embryos. In this system, mortality data and histopathological findings induced by organisms and by bacterium-free filtered broth were identical. The absence in chicken embryo tissues both of organisms and of an inflammatory infiltrate suggests a toxin etiology.

  15. Expression in Arabidopsis of a nucellus-specific promoter from watermelon (Citrullus lanatus).

    Science.gov (United States)

    Dwivedi, Krishna K; Roche, Dominique; Carman, John G

    2010-11-01

    Though many tissue-specific promoters have been identified, few have been associated specifically with the angiospermous megasporangium (nucellus). In the present study the 2000-bp regulatory region upstream to the watermelon, Citrullus lanatus (Thunb.) Matsum & Nakai, gene WM403 (GenBank accession no. AF008925), which shows nucellus-specific expression, was cloned from watermelon gDNA and fused to the β-glucuronidase reporter gene (GUS). The resulting plasmid, WM403 Prom::GUS(+), which also contained NPTII, was transformed into Arabidopsis thaliana ecotype Co1-0. Seedlings were selected on kanamycin-containing medium, and transformants were confirmed by PCR. GUS assays of T(3) transformants revealed weak promoter activation in epidermal layers of the placenta and locule septum during premeiotic ovule development but strong activation in the nucellus, embryo sac and early embryo, from early embryo sac formation to early globular embryo formation. Expression in seeds was absent thereafter. These results indicate that the WM403 promoter may be useful in driving nucellus-specific gene expression in plants including candidate genes for important nucellus-specific traits such as apospory or adventitious embryony. PMID:21802614

  16. Migration and Growth of Protoplanetary Embryos I: Convergence of Embryos in Protoplanetary Disks

    CERN Document Server

    Zhang, Xiaojia; Lin, Douglas N C; Li, Hui

    2014-01-01

    According to the core-accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses ($M_p$) in the range of a few Earth masses ($M_\\oplus$) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When $M_p > 10 M_\\oplus$, embryos efficiently accrete gas and evolve into cores of gas giants. We use numerical simulation to show that, despite streamline interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torque by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in the...

  17. Approaches to assessing doses to the embryo and fetus (invited paper)

    International Nuclear Information System (INIS)

    The availability of the required information input for embryo/fetus dosimetry due to internal emitters is far from satisfactory. A variety of anthropometric standards for reference both for national and international agencies have been proposed for assessing healthy in utero growth of the embryo/fetus. Numerous attempts have been made to define computational models of the pregnant woman, embryo/fetus and the placenta for obtaining S factors and SEE values. Human biokinetic information that enables estimation of the time integral of radioactivity in the embryo/fetus is rather scanty and available only for a few radionuclides. However, a number of organisations are working intensively to arrive at doses or dose coefficients due to internal emitters for formulating recommendations that could be adopted by national and international regulatory agencies. The present paper is an attempt to review the different approaches used in embryo/fetus dosimetry. The review includes a comparison of different national standards of anthropometric measurements of the embryo/fetus as a function of gestational period; the modelling of pregnant women, embryo/fetus and the placenta; use of this information for computation of photon-specific absorbed fractions, S factors and SEE values; a brief description of processes involved at placental level that allow or disallow placental transfer of specific materials such as nutrients, micronutrients, trace elements and their subsequent transfer to the embryo/fetus; biokinetic information on either stable or radionuclides and its applicability for computation of radioactivity in the embryo/fetus as well as in its associated component structures or for estimating fetal to maternal activity concentration ratios. A case of an inadvertent administration of therapeutic radioiodine to a pregnant woman is also presented. (author)

  18. Characterization and quantification of proteins secreted by single human embryos prior to implantation.

    Science.gov (United States)

    Poli, Maurizio; Ori, Alessandro; Child, Tim; Jaroudi, Souraya; Spath, Katharina; Beck, Martin; Wells, Dagan

    2015-11-01

    The use of in vitro fertilization (IVF) has revolutionized the treatment of infertility and is now responsible for 1-5% of all births in industrialized countries. During IVF, it is typical for patients to generate multiple embryos. However, only a small proportion of them possess the genetic and metabolic requirements needed in order to produce a healthy pregnancy. The identification of the embryo with the greatest developmental capacity represents a major challenge for fertility clinics. Current methods for the assessment of embryo competence are proven inefficient, and the inadvertent transfer of non-viable embryos is the principal reason why most IVF treatments (approximately two-thirds) end in failure. In this study, we investigate how the application of proteomic measurements could improve success rates in clinical embryology. We describe a procedure that allows the identification and quantification of proteins of embryonic origin, present in attomole concentrations in the blastocoel, the enclosed fluid-filled cavity that forms within 5-day-old human embryos. By using targeted proteomics, we demonstrate the feasibility of quantifying multiple proteins in samples derived from single blastocoels and that such measurements correlate with aspects of embryo viability, such as chromosomal (ploidy) status. This study illustrates the potential of high-sensitivity proteomics to measure clinically relevant biomarkers in minute samples and, more specifically, suggests that key aspects of embryo competence could be measured using a proteomic-based strategy, with negligible risk of harm to the living embryo. Our work paves the way for the development of "next-generation" embryo competence assessment strategies, based on functional proteomics. PMID:26471863

  19. Embryo culture and rapid propagation of Syringa

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li; DAI Li-min; SU Bao-ling

    2003-01-01

    Embryo of lilacs (Syringa L) culture in vitro and the rapid propagation were studied. The orthogonal experiments, including the selection of basal medium, embryo age and other factors such as sugar, benzyladenine (BA), naphthalene acetic acid (NAA) and glutamine (Gln), were carried out. The results indicated that the optimal medium for embryo culture was Monnier medium supplemented with NAA (0.001 mg@L-1), BA (0.1 mg@L-1), sugar (50 g@L-1), and Gln (400 mg@L-1), with a germination rate of 91.7% at least; the optimal embryo age was 50 d; and Gln had significant effects on the germination rate of embryo. Moreover, the optimal medium for subculture was MS+BA (2 mg@L-1)+NAA (0.001 mg@L-1)+Gln (0.5 mg@L-1), with the propagation coefficient of 3.6 at least.

  20. Rape embryogenesis. III. Embryo development in time

    Directory of Open Access Journals (Sweden)

    Teresa Tykarska

    2014-02-01

    Full Text Available It was found that the growth curve of the rape embryo axis is of triple sigmoid type. Embryo growth occurs in 3 phases corresponding to 3 different periods of development. Phase I includes growth of the apical cell up to it's division into two layers of octants. Phase II comprises the increase of the spherical proembryo to the change of its symmetry from radial to bilateral. Phase III includes, growth of the embryo from the heart stage up to the end of embryogenesis. In each phase the relative growth rate increases drastically and then diminishes. The differences in growth intensity during the same phase are several-fold. The growth intensity maximum of the embryo axis occurs in phase II. The phasic growth intensity maxima occur: in phase I during apical cell elongation, :before its division, and in phases II and III in the periods of cell division ;growth in globular and torpedo-shaped -shaped embryos.

  1. Nucleolar ultrastructure in bovine nuclear transfer embryos

    DEFF Research Database (Denmark)

    Kaňka, Jiří; Smith, Steven Dale; Soloy, Eva;

    1999-01-01

    (nonactivated) or S phase (activated) cytoplasts. Control embryos were fixed at the two-, four-, early eight- and late eight-cell stages; nuclear transfer embryos were fixed at 1 and 3 hr post fusion and at the two-, four-, and eight-cell stages. Control embryos possessed a nucleolar precursor body throughout...... at 1 hr after fusion and, by 3 hr after fusion, it was restored again. At this time, the reticulated fibrillo-granular nucleolus had an almost round shape. The nucleolar precursor body seen in the two-cell stage nuclear transfer embryos consisted of intermingled filamentous components and secondary...... time intervals after fusion. In the two-cell stage nuclear transfer embryo, the originally reticulated nucleolus of the donor blastomere had changed into a typical nucleolar precursor body consisting of a homogeneous fibrillar structure. A primary vacuole appeared in the four-cell stage nuclear...

  2. The Well of the Well (WOW) system: an efficient approach to improve embryo development

    DEFF Research Database (Denmark)

    Vajta, G; Korösi, T; Du, Y;

    2008-01-01

    (WOW) system consisting of microwells formed on the bottom of the culture dish was tested in three mammalian species including humans. The WOW system has resulted in significant improvement compared the drops for culture of in vitro matured and parthenogenetically activated porcine oocytes or in vivo......Transfer of human embryos at the blastocyst stage may offer considerable benefits including the increased implantation rates and decreased risks of multiple pregnancies, however, it requires an efficient and reliable in vitro embryo culture system. In our study, the effect of the Well of the Well......-derived mouse zygotes. In human, using sibling oocyte design, embryos cultured in WOW have developed in a significantly higher proportion to the blastocyst stage than embryos cultured traditionally (55% in WOW and 37% in conventional culture; P<0.05). In an independent study, also in human, a total of 48...

  3. A prospective randomized controlled trial of Wallace and Rocket embryo transfer catheters.

    Science.gov (United States)

    El-Shawarby, Salem A; Ravhon, Amir; Skull, Jonathan; Ellenbogen, Adrian; Trew, Geoffrey; Lavery, Stuart

    2008-10-01

    The aim of this study was to compare the efficacy of two embryo transfer catheters: Wallace and Rocket Embryon in an IVF programme of a tertiary referral university centre. A total of 308 patients undergoing embryo transfer were prospectively randomized to either a transfer with the Wallace catheter or a transfer with the Rocket catheter. The main outcome measure in this study was the clinical pregnancy rate, and secondary outcome measures included implantation rate, visibility of the catheter under ultrasound, number of retained embryos post transfer, and whether change of catheter was required. In addition, patient discomfort during the procedure was recorded. Pregnancy and implantation rates were similar when Wallace or Rocket catheters were used. However, for the Rocket catheter, the tip was more often clearly seen on ultrasound and it had a lower rate of retained embryos in the catheter after transfer (P < 0.05). Experience with different transfer catheters is recommended for difficult cases. PMID:18854110

  4. Rearing of sea lamprey, Petromyzon marinus, embryos in distilled water

    Science.gov (United States)

    Piavis, George W.; Howell, John H.

    1969-01-01

    Most embryological studies of lampreys in the Great Lakes have been conducted with filtered water from Lake Huron. Although this water was entirely satisfactory for the earlier work, the present need for knowledge of the effects of various compounds on embryological development requires that the initial medium be sterile. The purpose of the present study was to determine whether sea lamprey embryos could be successfully reared in distilled water. Mature sea lampreys were collected from the Ocqueoc River, Presque Isle County, Michigan, and transferred to the Hammond Bay Biological Station where eggs were stripped and fertilized according to the method of Piavis. After activation was ascertained to be 90-100% complete, the embryos were washed 3-5 timesexperimentals with commercially obtained U.S.P. distilled water and controls with filtered Lake Huron water.

  5. ‘Vanishing embryo syndrome’ in IVF/ICSI

    DEFF Research Database (Denmark)

    Hvidtjørn, Dorte; Grove, Jakob; Schendel, Diana; Væth, Michael; Ernst, Erik; Nielsen, Lene F.; Thorsen, Poul

    2005-01-01

    BACKGROUND: In a Danish population-based cohort study assessing the risk of cerebral palsy in children bornafter IVF, we made some interesting observations regarding ‘vanishing co-embryos’. METHODS andRESULTS: All live-born children born in Denmark from 1 January 1995 to 31 December 2000 were...... included inthis analysis. The children conceived by IVF/ICSI (9444) were identified through the IVF Register, the childrenconceived without IVF/ICSI (395 025) were identified through The Danish Medical Birth Register. Main outcomemeasure was the incidence of cerebral palsy. Within the IVF/ICSI children we...... found indications of an increasedrisk of cerebral palsy in those children resulting from pregnancies, where the number of embryos transferred washigher than the number of children born. CONCLUSIONS: The association between vanishing embryo syndromeand incidence of cerebral palsy following IVF requires...

  6. ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 Are Responsible for Making Omega-7 Fatty Acids in the Arabidopsis Aleurone.

    Science.gov (United States)

    Bryant, Fiona M; Munoz-Azcarate, Olaya; Kelly, Amélie A; Beaudoin, Frédéric; Kurup, Smita; Eastmond, Peter J

    2016-09-01

    Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3 We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ(9) desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3 Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ(9) desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids. PMID:27462083

  7. Multiple Patterns of Regulation and Overexpression of a Ribonuclease-Like Pathogenesis-Related Protein Gene, OsPR10a, Conferring Disease Resistance in Rice and Arabidopsis

    Science.gov (United States)

    He, Siou-Luan; Chen, Jyh-Lang; Jiang, Jian-Zhi; Chen, Bo-Hong; Hou, Yi-Syuan; Chen, Ruey-Shyang; Hong, Chwan-Yang; Ho, Shin-Lon

    2016-01-01

    An abundant 17 kDa RNase, encoded by OsPR10a (also known as PBZ1), was purified from Pi-starved rice suspension-cultured cells. Biochemical analysis showed that the range of optimal temperature for its RNase activity was 40–70°C and the optimum pH was 5.0. Disulfide bond formation and divalent metal ion Mg2+ were required for the RNase activity. The expression of OsPR10a::GUS in transgenic rice was induced upon phosphate (Pi) starvation, wounding, infection by the pathogen Xanthomonas oryzae pv. oryzae (Xoo), leaf senescence, anther, style, the style-ovary junction, germinating embryo and shoot. We also provide first evidence in whole-plant system, demonstrated that OsPR10a-overexpressing in rice and Arabidopsis conferred significant level of enhanced resistance to infection by the pathogen Xoo and Xanthomona campestris pv. campestris (Xcc), respectively. Transgenic rice and Arabidopsis overexpressing OsPR10a significantly increased the length of primary root under phosphate deficiency (-Pi) condition. These results showed that OsPR10a might play multiple roles in phosphate recycling in phosphate-starved cells and senescing leaves, and could improve resistance to pathogen infection and/or against chewing insect pests. It is possible that Pi acquisition or homeostasis is associated with plant disease resistance. Our findings suggest that gene regulation of OsPR10a could act as a good model system to unravel the mechanisms behind the correlation between Pi starvation and plant-pathogen interactions, and also provides a potential application in crops disease resistance. PMID:27258121

  8. The effect of alpha-amanitin on the Arabidopsis seed proteome highlights the distinct toles of stored and neosynthesizes mRNAs during germination

    OpenAIRE

    Rajjou, Loïc; Gallardo, Karine; Debeaujon, Isabelle; Vandekerckhove, Joël; Job, Claudette; Job, Dominique

    2004-01-01

    To investigate the role of stored and neosynthesized mRNAs in seed germination, we examined the effect of alpha-amanitin, a transcriptional inhibitor targeting RNA polymerase II, on the germination of nondormant Arabidopsis seeds. We used transparent testa mutants, of which seed coat is highly permeable, to better ascertain that the drug can reach the embryo during seed imbibition. Even with the most permeable mutant (tt2-1), germination (radicle protrusion) occurred in the absence of transcr...

  9. Arabidopsis MAP kinase 4 negatively regulates systemic acquired resistance

    DEFF Research Database (Denmark)

    Petersen, M.; Brodersen, P.; Naested, H.;

    2000-01-01

    Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) revels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern...... of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression....

  10. Arabidopsis map kinase 4 negatively regulates systemic acquired resistance

    DEFF Research Database (Denmark)

    Brodersen, P; Johansen, Bo; Petersen, M;

    2000-01-01

    Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) levels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern...... of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression....

  11. Protein phosphorylation during coconut zygotic embryo development

    International Nuclear Information System (INIS)

    Evidence was obtained on the occurrence of protein threonine, serine, and tyrosine (Tyr) kinases in developing coconut (Cocos nucifera L.) zygotic embryos, based on in vitro phosphorylation of proteins in the presence of [gamma-32P]ATP, alkaline treatment, and thin-layer chromatography analysis, which showed the presence of [32P]phosphoserine, [32P]phosphothreonine, and [32P]phosphotyrosine in [32P]-labeled protein hydrolyzates. Tyr kinase activity was further confirmed in extracts of embryos at different stages of development using antiphosphotyrosine monoclonal antibodies and the synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src (RR-SRC), which is specific for Tyr kinases. Anti-phosphotyrosine western blotting revealed a changing profile of Tyr-phosphorylated proteins during embryo development. Tyr kinase activity, as assayed using RR-SRC, also changed during embryo development, showing two peaks of activity, one during early and another during late embryo development. In addition, the use of genistein, a Tyr kinase inhibitor, diminished the ability of extracts to phosphorylate RR-SRC. Results presented here show the occurrence of threonine, serine, and Tyr kinases in developing coconut zygotic embryos, and suggest that protein phosphorylation, and the possible inference of Tyr phosphorylation in particular, may play a role in the coordination of the development of embryos in this species

  12. Genetic Analyses of Meiotic Recombination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Meiosis is essential for sexual reproduction and recombination is a critical step required for normal meiosis. Understanding the underlying molecular mechanisms that regulate recombination ie important for medical, agricultural and ecological reasons. Readily available molecular and cytological tools make Arabidopsis an excellent system to study meiosis. Here we review recent developments in molecular genetic analyses on meiotic recombination. These Include studies on plant homologs of yeast and animal genes, as well as novel genes that were first identified in plants. The characterizations of these genes have demonstrated essential functions from the initiation of recombination by double-strand breaks to repair of such breaks, from the formation of double-Holliday junctions to possible resolution of these junctions, both of which are critical for crossover formation. The recent advances have ushered a new era in plant meiosis, in which the combination of genetics, genomics, and molecular cytology can uncover important gene functions.

  13. Embryo Transfer (Techniques, Donors, and Recipients).

    Science.gov (United States)

    Phillips, Patrick E; Jahnke, Marianna M

    2016-07-01

    Commercial embryo transfer has evolved as an art and as a science since the early 1970s. Today's multiple ovulation embryo transfer is a widely used reproductive tool on many farms and is performed by veterinarians throughout the world. Propagation of the female genomes of select donors, through embryo transfer, has allowed a rapid progression of genetic gain in many breeds, much like what happened with artificial insemination since the 1940s. Advancement of this technology is migrating to in vitro fertilization technology today, allowing a higher volume of offspring to be produced with sex selection in the laboratory. PMID:27140299

  14. Rape embryogenesis. III. Embryo development in time

    OpenAIRE

    Teresa Tykarska

    2014-01-01

    It was found that the growth curve of the rape embryo axis is of triple sigmoid type. Embryo growth occurs in 3 phases corresponding to 3 different periods of development. Phase I includes growth of the apical cell up to it's division into two layers of octants. Phase II comprises the increase of the spherical proembryo to the change of its symmetry from radial to bilateral. Phase III includes, growth of the embryo from the heart stage up to the end of embryogenesis. In each phase the relativ...

  15. An Arabidopsis embryonic lethal mutant with reduced expression of alanyl—t RNA synthetase gene

    Institute of Scientific and Technical Information of China (English)

    SUNJIANGE; XIAOLIYAO; 等

    1998-01-01

    In present paper,one of the T-DNA insertional embryonic lethal mutant of Arabidopsis is identified and designated as acd mutant.The embryo developmant of this mutant is arrested in globular stage,The cell division pattern is abnormal during early embryogenesis and results in distubed cellular differentiation.Most of mutant embryos are finally degenerated and aborted in globular stage,However,a few of them still can germinate in agar palte and produce seedlings with shoter hypoctyl and distorted shoot meristem.To understand the molecular basis of the phenotype of this mutant,the joint fragment of T-DNA/plant DNA is isolated by plasmid rescue and Dig-labeled as probe for cDNA library screening.According to the sequence analysis and similarity searching,a 936 bp cDNA sequence(EMBL accession #:Y12555)from selectoed positive clone shows a 99.8%(923/925bp) sequence homolgy with Alanyl-tRNA Synthetase(AlaRS) gene of Arabidopsis thaliana.Furthermore,the data of in situ hybridization experiment indicate that the expression of Ala RS gene is weak in early embryogenesis and declines along with globular embryodevelopment in this mutant Accordingly,the reduced expression of Ala RS gene may be closely related to the morphological changes in early embryogenesis of this lethal mutant.

  16. Evaluating recipient and embryo factors that affect pregnancy rates of embryo transfer in beef cattle.

    Science.gov (United States)

    Spell, A R; Beal, W E; Corah, L R; Lamb, G C

    2001-07-15

    The objectives of this experiment were to determine the effects of corpus luteum characteristics, progesterone concentration, donor-recipient synchrony, embryo quality, type, and developmental stage on pregnancy rates after embryo transfer. We synchronized 763 potential recipients for estrus using one of two synchronization protocols: two doses of PGF2alpha (25 mg i.m.) given 11 d apart (Location 1); and, a single norgestomet implant for 7 d with one dose of PGF2alpha (25 mg i.m.) 24 h before implant removal (Location 2). At embryo transfer, ovaries were examined by rectal palpation and ultrasonography. Of the 526 recipients presented for embryo transfer, 122 received a fresh embryo and 326 received a frozen embryo. Pregnancy rates were greater (P 0.1). There was a significant, positive simple correlation between CL diameter or luteal tissue volume and plasma progesterone concentration (r = 0.15, P quality. PMID:11480620

  17. Functional analysis of the Hikeshi-like protein and its interaction with HSP70 in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Shinya; Ohama, Naohiko; Mizoi, Junya [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Shinozaki, Kazuo [RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045 (Japan); Yamaguchi-Shinozaki, Kazuko, E-mail: akys@mail.ecc.u-tokyo.ac.jp [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2014-07-18

    Highlights: • HKL, a Hikeshi homologous gene is identified in Arabidopsis. • HKL interacts with two HSP70 isoforms and regulates the subcellular localization of HSC70-1. • The two HSP70 translocate into nucleus in response to heat stress. • Overexpression of HKL confers thermotolerance in transgenic plants. - Abstract: Heat shock proteins (HSPs) refold damaged proteins and are an essential component of the heat shock response. Previously, the 70 kDa heat shock protein (HSP70) has been reported to translocate into the nucleus in a heat-dependent manner in many organisms. In humans, the heat-induced translocation of HSP70 requires the nuclear carrier protein Hikeshi. In the Arabidopsis genome, only one gene encodes a protein with high homology to Hikeshi, and we named this homolog Hikeshi-like (HKL) protein. In this study, we show that two Arabidopsis HSP70 isoforms accumulate in the nucleus in response to heat shock and that HKL interacts with these HSP70s. Our histochemical analysis revealed that HKL is predominantly expressed in meristematic tissues, suggesting the potential importance of HKL during cell division in Arabidopsis. In addition, we show that HKL regulates HSP70 localization, and HKL overexpression conferred thermotolerance to transgenic Arabidopsis plants. Our results suggest that HKL plays a positive role in the thermotolerance of Arabidopsis plants and cooperatively interacts with HSP70.

  18. Evolution of NIN-like proteins in Arabidopsis, rice, and Lotus japonicus.

    Science.gov (United States)

    Schauser, Leif; Wieloch, Wioletta; Stougaard, Jens

    2005-02-01

    Genetic studies in Lotus japonicus and pea have identified Nin as a core symbiotic gene required for establishing symbiosis between legumes and nitrogen fixing bacteria collectively called Rhizobium. Sequencing of additional Lotus cDNAs combined with analysis of genome sequences from Arabidopsis and rice reveals that Nin homologues in all three species constitute small gene families. In total, the Arabidopsis and rice genomes encode nine and three NIN-like proteins (NLPs), respectively. We present here a bioinformatics analysis and prediction of NLP evolution. On a genome scale we show that in Arabidopsis, this family has evolved through segmental duplication rather than through tandem amplification. Alignment of all predicted NLP protein sequences shows a composition with six conserved modules. In addition, Lotus and pea NLPs contain segments that might characterize NIN proteins of legumes and be of importance for their function in symbiosis. The most conserved region in NLPs, the RWP-RK domain, has secondary structure predictions consistent with DNA binding properties. This motif is shared by several other small proteins in both Arabidopsis and rice. In rice, the RWP-RK domain sequences have diversified significantly more than in Arabidopsis. Database searches reveal that, apart from its presence in Arabidopsis and rice, the motif is also found in the algae Chlamydomonas and in the slime mold Dictyostelium discoideum. Thus, the origin of this putative DNA binding region seems to predate the fungus-plant divide. PMID:15785851

  19. CFTR mediates bicarbonate-dependent activation of miR-125b in preimplantation embryo development

    Institute of Scientific and Technical Information of China (English)

    Yong Chao Lu; Alvin Chun Hang Ma; Anskar Yu Hung Leung; He Feng Huang; Hsiao Chang Chan; Hui Chen; Kin Lam Fok; Lai Ling Tsang; Mei Kuen Yu; Xiao Hu Zhang; Jing Chen; Xiaohua Jiang; Yiu Wa Chung

    2012-01-01

    Although HCO3-is known to be required for early embryo development,its exact role remains elusive.Here we report that HCO3-acts as an environmental cue in regulating miR-125b expression through CFTR-mediated influx during preimplantation embryo development.The results show that the effect of HCO3-on preimplantation embryo development can be suppressed by interfering the function of a HCO3--conducting channel,CFTR,by a specific inhibitor or gene knockout.Removal of extracellular HCO3-or inhibition of CFTR reduces miR-125b expression in 2 cell-stage mouse embryos.Knockdown of miR-125b mimics the effect of HCO3-removal and CFTR inhibition,while injection of miR-125b precursor reverses it.Downregulation of miR-125b upregulates p53 cascade in both human and mouse embryos.The activation of miR-125b is shown to be mediated by sAC/PKA-dependent nuclear shuttling of NF-KB.These results have revealed a critical role of CFTR in signal transduction linking the environmental HCO3-to activation of miR-125b during preimplantation embryo development and indicated the importance of ion channels in regulation of miRNAs.

  20. Valuing embryos as both commodities and singularities.

    Science.gov (United States)

    Legge, Michael; Fitzgerald, Ruth

    2016-03-11

    An argument put forward against gamete and embryo donation, sale and research, is that to do so would treat the gametes or embryos as objects with no intrinsic value as human. Instead, gametes and embryos created and used for donation, sale or research, can be considered more like a commodity created and traded for economic exchange--something that is valuable only for the amount of money or other goods and services that others are willing to exchange. While Kant asserts that humans have dignity rather than object worth, the provision of human gametes and embryos are progressively becoming utilities for resolving childlessness and for certain research investigations. In this paper we discuss the commodity market and the relationship to human reproduction material. PMID:27005877

  1. Bovine in vitro embryo production : An overview

    Directory of Open Access Journals (Sweden)

    V. S. Suthar

    Full Text Available Dairy industry perfected the application of the first reproductive biotechnology, i.e. artificial insemination (AI - a great success story and also remains the user of embryo transfer technology (ETT. In addition, recently the researchers taking interest to embraced the field of Transvaginal OocyteRecovery (TVOR and in vitro production (IVEP of embryos. IVF provides the starting point for the generation of reproductive material for a number of advanced reproduction techniques including sperm microinjection and nuclear transfer (cloning. In several countries commercial IVF facilities are already being employed by cattle ET operators. Various research groups have reported on modification of TVOR technique to give greater efficiency. Much research is still needed in domestic animal (Especially Indian species on mechanisms controlling embryo development and on development of totally in vitro system for embryo culture. [Vet World 2009; 2(12.000: 478-479`

  2. Predator recognition in rainbowfish, Melanotaenia duboulayi, embryos.

    Directory of Open Access Journals (Sweden)

    Lois Jane Oulton

    Full Text Available Exposure to olfactory cues during embryonic development can have long term impacts on birds and amphibians behaviour. Despite the vast literature on predator recognition and responses in fishes, few researchers have determined how fish embryos respond to predator cues. Here we exposed four-day-old rainbowfish (Melanotaenia duboulayi embryos to cues emanating from a novel predator, a native predator and injured conspecifics. Their response was assessed by monitoring heart rate and hatch time. Results showed that embryos have an innate capacity to differentiate between cues as illustrated by faster heart rates relative to controls. The greatest increase in heart rate occurred in response to native predator odour. While we found no significant change in the time taken for eggs to hatch, all treatments experienced slight delays as expected if embryos are attempting to reduce exposure to larval predators.

  3. Characterization of a diverse secretome generated by the mouse preimplantation embryo in vitro

    Directory of Open Access Journals (Sweden)

    O'Neill Chris

    2010-06-01

    Full Text Available Abstract This study investigates the suitability of surface-enhanced laser desorption and ionization time-of-flight (SELDI-TOF and electrospray ionization (ESI mass spectrometry for analysis of the proteins released by the mouse preimplantation embryo in vitro. SELDI-TOF analysis with CM10 or IMAC30 (but not Q10 protein chips detected a protein peak at m/z ~8570 released by both C57BL6 and hybrid embryos. No other peaks unique to the presence of the embryo were identified with this method. ESI mass spectrometry of tryptic digests of embryo-conditioned media identified a total of 20 proteins released during development from the zygote to blastocyst stage. Four proteins were expressed in at least 7 out of 8 cultures tested, one of these (lactate dehydrogenase B was in all cultures. A further five proteins were in at least half of the cultures and 11 more proteins were in at least one culture. The expression of two of these proteins is essential for preimplantation embryo development (NLR family, pyrin domain containing 5 and peptidyl arginine deiminase, type VI. A further four proteins detected have roles in redox regulation of cells, and three others are capable of inducing post-translational modifications of proteins. This study shows the feasibility of ESI mass spectrometry for identifying the proteins secreted by the preimplantation embryo in vitro. This analysis identifies a range of targets that now require detailed functional analysis to assess whether their release by the embryo is an important property of early embryo development.

  4. The threshold number of protons to induce an adaptive response in zebrafish embryos

    International Nuclear Information System (INIS)

    In this study, microbeam protons were used to provide the priming dose to induce an in vivo radioadaptive response (RAR) in the embryos of zebrafish, Danio rerio, against subsequent challenging doses provided by x-ray photons. The microbeam irradiation system (Single-Particle Irradiation System to Cell, acronym SPICE) at the National Institute of Radiological Sciences (NIRS), Japan, was employed. The embryos were dechorionated at 4 h post fertilisation (hpf) and irradiated at 5 hpf by microbeam protons. For each embryo, one irradiation point was chosen, to which 5, 10, 20, 30, 40, 50, 100, 200, 300 and 500 protons each with an energy of 3.4 MeV were delivered. The embryos were returned to the incubator until 10 hpf to further receive the challenging exposure, which was achieved using 2 Gy of x-ray irradiation, and then again returned to the incubator until 24 hpf for analyses. The levels of apoptosis in zebrafish embryos at 25 hpf were quantified through terminal dUTP transferase-mediated nick end-labelling (TUNEL) assay. The results revealed that at least 200 protons (with average radiation doses of about 300 and 650 mGy absorbed by an irradiated epithelial and deep cell, respectively) would be required to induce RAR in the zebrafish embryos in vivo. Our previous investigation showed that 5 protons delivered at 10 points on an embryo would already be sufficient to induce RAR in the zebrafish embryos. The difference was explained in terms of the radiation-induced bystander effect as well as the rescue effect. (paper)

  5. Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos.

    Science.gov (United States)

    Akcha, F; Spagnol, C; Rouxel, J

    2012-01-15

    We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with the surrounding waters and are hence particularly exposed to these potentially dangerous substances. In the course of this study, differences in genotoxic and embryotoxic responses were observed in the various experiments, possibly due to differences in pollutant sensitivity between the tested genitor lots. Glyphosate and Roundup had no effect on oyster development at the concentrations tested, whereas diuron significantly affected embryo-larval development from the lowest tested concentration of 0.05 μg L⁻¹, i.e. an environmentally realistic concentration. Diuron may therefore have a significant impact on oyster recruitment rates in the natural environment. Our spermiotoxicity study revealed none of the tested herbicides to be cytotoxic for oyster spermatozoa. However, the alkaline comet assay showed diuron to have a significant genotoxic effect on oyster spermatozoa at concentrations of 0.05 μg L⁻¹ upwards. Conversely, no effects due to diuron exposure were observed on sperm mitochondrial function or acrosomal membrane integrity. Although our initial results showed no negative effect on sperm function, the possible impact on fertilization rate and the consequences of the transmission of damaged DNA for

  6. Seed and Embryo Germination in Ardisia crenata

    OpenAIRE

    Masayuki Oda; Shuji Shiozaki; Hideyuki Tanaka; Hisa Yokoyama; Takahiro Tezuka

    2012-01-01

    Ardisia crenata is an evergreen shrub with attractive bright red berries. Although this species is usually propagated by seed, the seeds take a long time to germinate with conventional sowing methods. We investigated the germination capacity of seeds and embryos collected in different months and the effects of seed storage conditions, germination temperature, water permeability of the seed coat, and the endosperm on seed germination. Seeds and embryos collected in late September or later show...

  7. Defining embryo donation: an Ethics Committee opinion.

    Science.gov (United States)

    2016-07-01

    Building families through the adoption of children has been supported by human society throughout history. The ethical appropriateness of patients donating embryos to other patients for family building, or for research, is well established and is affirmed by this Committee. The use of the term ''adoption'' for embryos is inaccurate and should be avoided. This document replaces the ASRM Ethics Committee statement by the same name, last published in 2013 (Fertil Steril 2013;99:1846-7). PMID:27001380

  8. Advanced optical imaging in living embryos

    OpenAIRE

    Canaria, Christie A.; Lansford, Rusty

    2010-01-01

    Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recen...

  9. Embryo disposition and the new death scene

    Directory of Open Access Journals (Sweden)

    Ellison, David

    2011-01-01

    Full Text Available In the IVF clinic - a place designed principally for the production and implantation of embryos - scientists and IVF recipients are faced with decisions regarding the disposition of frozen embryos. At this time there are hundred of thousands of cryopreserved embryos awaiting such determinations. They may be thawed for transfer to the woman herself, they may be donated for research or for use by other infertile couples, they may remain in frozen storage, or they may variously be discarded by being allowed to 'succumb', or 'perish'. Where the choice is discard, some IVF clients have chosen to formalise the process through ceremony. A new language is emerging in response to the desires of the would-be-parents who might wish to characterise the discard experience as a ‘good death’. This article examines the procedure known as ‘compassionate transfer’ where the embryo to be discarded is placed in the woman’s vagina where it is clear that it will not develop further. An alternate method has the embryo transferred in the usual manner but without the benefit of fertility-enhancing hormones at a point in the cycle unreceptive to implantation. The embryo destined for disposal is thus removed from the realm of technological possibility and ‘returned’ to the female body for a homely death. While debates continue about whether or not embryos constitute life, new practices are developing in response to the emotional experience of embryo discard. We argue that compassionate transfer is a death scene taking shape. In this article, we take the measure of this new death scene’s fabrication, and consider the form, significance, and legal complexity of its ceremonies.

  10. Glassfrog embryos hatch early after parental desertion

    OpenAIRE

    Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-01-01

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested th...

  11. Rape embryogenesis. II. Development of embryo proper

    OpenAIRE

    Teresa Tykarska

    2015-01-01

    It was found in the continued studies on rape embryogenesis, started by the description of the proembryo (Tykarska, 1976) that the development of embryo is extremely regular and based on differentiating divisions. It appeared that the transverse segmentation boundary and cell walls separating the mother cells of the histogens in the proembryo can be distinguished in all the later stages of the embryo. The border between the cytoledons and epicotyl part of the embryonal axis, and the hypocotyl...

  12. Comparative radiosensitivity of Medfly cells and embryos.

    OpenAIRE

    Cavalloro, R.; Muñiz, M; Pozzi, G

    1984-01-01

    This research is dealing with the effect of 6O Co gamma radiation on cultured "In vitro" cells and on embryos at different developmental stages, of Ceratitis capitata Wiedemann. The parameters ana1yzed for both the cells and the embryos were growrh, survival and mortality rates. The immediate and late effects of irradiation were also studied at the level of egg hatching, larval life cycle, emergence of adults and their fertility. A particular result that became evident in the cormparison of t...

  13. Arabidopsis thaliana—Aphid Interaction

    OpenAIRE

    Louis, Joe; Singh, Vijay,; Shah, Jyoti

    2012-01-01

    Aphids are important pests of plants that use their stylets to tap into the sieve elements to consume phloem sap. Besides the removal of photosynthates, aphid infestation also alters source-sink patterns. Most aphids also vector viral diseases. In this chapter, we will summarize on recent significant findings in plant-aphid interaction, and how studies involving Arabidopsis thaliana and Myzus persicae (Sülzer), more commonly known as the green peach aphid (GPA), are beginning to provide impor...

  14. Selenium Speciation in Arabidopsis Thaliana

    OpenAIRE

    Wang, Xiaoou

    2011-01-01

    Selenium has been proved as an essential micronutrient and is beneficial to animals and humans. It is a structural component of the important antioxidant enzyme, glutathione peroxidase, which catalyzes reactions to detoxify reactive oxygen species. However, the essentiality of Se in plants remains controversial and the protective role of Se in plants has rarely been investigated. In this study, Arabidopsis thaliana was grown in controlled environments having selenate or selenite enriched medi...

  15. Effective mutagenesis of Arabidopsis by heavy ion beam-irradiation

    International Nuclear Information System (INIS)

    Full text: Arabidopsis researches frequently include the genetic approach, so efficient, convenient, and safe methods for mutagenesis are required. Currently, the most popular method for in house mutagenesis is application of EMS. Although this method is very effective, its base substitution-type mutations often gives leaky mutants with residual gene functions, leading some difficulty in understanding the corresponding gene functions. Heavy ion beam generated by accelerators gives highest energy transfer rates among known radiation-based mutagenesis methods including X ray, gamma ray, fast neutron, electron and proton irradiation. This feature is thought to give high frequency of the double strand break of genomic DNA and resultant short deletions, resulting frame shift-type mutations. At RIKEN Accelerator Research Facility (RARF, http://www.rarf.riken.go.jp/index-e.html), we have optimized conditions for effective mutagenesis of Arabidopsis regarding to ion species and irradiation dose, and achieved comparable mutation rates to the method with EMS. (author)

  16. To transfer fresh or thawed embryos?

    DEFF Research Database (Denmark)

    Pinborg, Anja

    2012-01-01

    Worldwide freezing and thawing of embryos has been increasingly used since the first infant was born as a result of this technique in 1984. The use of frozen embryo replacement (FER) currently even exceeds the number of fresh cycles performed in some countries. This article discusses the pros and...... the subsequent development of fetus and child. Because larger and more detailed data sets are available for early cleavage-stage embryo freezing and slow freezing, they are the main focus of this review.......Worldwide freezing and thawing of embryos has been increasingly used since the first infant was born as a result of this technique in 1984. The use of frozen embryo replacement (FER) currently even exceeds the number of fresh cycles performed in some countries. This article discusses the pros and...... cons of FER versus fresh-embryo transfer with regard to both single-cycle and cumulative pregnancy and delivery rates. The review discusses the obvious advantages of FER: minimizing the proportion of pharmacological and surgical treatments, and lowering the risk of ovarian hyperstimulation syndrome and...

  17. Cryopreservation of Arachis pintoi (leguminosae) somatic embryos.

    Science.gov (United States)

    Rey, H Y; Faloci, M; Medina, R; Dolce, N; Engelmann, F; Mroginski, L

    2013-01-01

    In this study, we successfully cryopreserved cotyledonary somatic embryos of diploid and triploid Arachis pintoi cytotypes using the encapsulation-dehydration technique. The highest survival rates were obtained when somatic embryos were encapsulated in calcium alginate beads and precultured in agitated (80 rpm) liquid establishment medium (EM) with daily increasing sucrose concentration (0.50, 0.75, and 1.0 M). The encapsulated somatic embryos were then dehydrated with silica gel for 5 h to 20% moisture content (fresh weight basis) and cooled either rapidly (direct immersion in liquid nitrogen, LN) or slowly (1 degree C per min from 25 degree C to -30 degree C followed by immersion in LN). Beads were kept in LN for a minimum of 1 h and then were rapidly rewarmed in a 30 degree C water-bath for 2 min. Finally, encapsulated somatic embryos were post-cultured in agitated (80 rpm) liquid EM with daily decreasing sucrose concentration (0.75 and 0.5 M) and transferred to solidified EM. Using this protocol, we obtained 26% and 30% plant regeneration from cryopreserved somatic embryos of diploid and triploid cytotypes. No morphological abnormalities were observed in any of the plants regenerated from cryopreserved embryos and their genetic stability was confirmed with 10 isozyme systems and nine RAPD profiles. PMID:24441368

  18. NCP1/AtMOB1A Plays Key Roles in Auxin-Mediated Arabidopsis Development

    Science.gov (United States)

    Song, Lizhen; Wang, Yanli; Cheng, Youfa

    2016-01-01

    MOB1 protein is a core component of the Hippo signaling pathway in animals where it is involved in controlling tissue growth and tumor suppression. Plant MOB1 proteins display high sequence homology to animal MOB1 proteins, but little is known regarding their role in plant growth and development. Herein we report the critical roles of Arabidopsis MOB1 (AtMOB1A) in auxin-mediated development in Arabidopsis. We found that loss-of-function mutations in AtMOB1A completely eliminated the formation of cotyledons when combined with mutations in PINOID (PID), which encodes a Ser/Thr protein kinase that participates in auxin signaling and transport. We showed that atmob1a was fully rescued by its Drosophila counterpart, suggesting functional conservation. The atmob1a pid double mutants phenocopied several well-characterized mutant combinations that are defective in auxin biosynthesis or transport. Moreover, we demonstrated that atmob1a greatly enhanced several other known auxin mutants, suggesting that AtMOB1A plays a key role in auxin-mediated plant development. The atmob1a single mutant displayed defects in early embryogenesis and had shorter root and smaller flowers than wild type plants. AtMOB1A is uniformly expressed in embryos and suspensor cells during embryogenesis, consistent with its role in embryo development. AtMOB1A protein is localized to nucleus, cytoplasm, and associated to plasma membrane, suggesting that it plays roles in these subcellular localizations. Furthermore, we showed that disruption of AtMOB1A led to a reduced sensitivity to exogenous auxin. Our results demonstrated that AtMOB1A plays an important role in Arabidopsis development by promoting auxin signaling. PMID:26942722

  19. G2 Checkpoint Responses in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Britt, Anne

    2013-03-18

    This project focused on the mechanism and biological significance of the G2 arrest response to replication stress in plants. We employed both forward and reverse genetic approaches to identify genes required for this response. A total of 3 different postdocs, 5 undergraduates, and 2 graduate students participated in the project. We identified several genes required for damage response in plants, including homologs of genes previously identified in animals (ATM and ATR), novel, a plant-specific genes (SOG1) and a gene known in animals but previously thought to be missing from the Arabidopsis genome (ATRIP). We characterized the transcriptome of gamma-irradiated plants, and found that plants, unlike animals, express a robust transcriptional response to damage, involving genes that regulate the cell cycle and DNA metabolism. This response requires both ATM and the transcription factor SOG1. We found that both ATM and ATR play a role in meiosis in plants. We also found that plants have a cell-type-specific programmed cell death response to ionizing radiation and UV light, and that this response requires ATR, ATM, and SOG1. These results were published in a series of 5 papers.

  20. Der Embryo: Eine junge Erfindung? The Embryo: A recent Invention?

    Directory of Open Access Journals (Sweden)

    Ute Frietsch

    2003-07-01

    Full Text Available Die Veröffentlichung des Max-Planck-Institutes für Geschichte sammelt Beiträge, die im Rahmen einer Konferenz der internationalen und interdisziplinären Arbeitsgruppe zur Geschichte der Geburt 1999 in Göttingen entstanden sind. Schwangerschaftserfahrung von Frauen und wissenschaftliche Zugriffe von Theologen, Anatomen, Medizinern und Juristen auf Ungeborene, Frauenkörper und Gesellschaftskörper werden programmatisch miteinander konfrontiert. Gearbeitet wird mit unterschiedlichen Perspektiven, Zeitausschnitten und Größenverhältnissen. Sowohl Divergenzen als auch Zusammenhänge von Körpergeschichte und Bevölkerungs- oder Biowissenschaft werden schlaglichtartig in Fallstudien beleuchtet. Die Biologisierung der Schwangerschaft in der Neuzeit wird aus ihrer Verwissenschaftlichung erklärt.10 interdisciplinary contributions dealing with the conflicting fields between personal experiences and the biologisation of pregnancy in modern times. This anthology published by the Max Planck Institute for History features a variety of contributions which came into being during a conference of the international and interdisciplinary working group on the history of birth. The conference took place in Göttingen in 1999. The anthology features the experiences with pregnancy of different women as well as scientific perspectives on embryos, women’s bodies, and societal bodies by theologians, anatomists, physicians, and jurists. The different contributions employ different perspectives, time periods, and scales. Case studies introduce and highlight diverging and converging perspectives on the history of the body, population studies, and biology, and explain how the advancement of science as well as societal processes caused pregnancy to become biologised in modern times.

  1. Use of versapoint to refashion the cervical canal to overcome unusually difficult embryo transfers and improve in-vitro fertilization-embryo transfer outcome: A case series

    Directory of Open Access Journals (Sweden)

    Nalini Mahajan

    2011-01-01

    Full Text Available Background : Smooth atraumatic embryo transfer is paramount for the success of in-vitro fertilization (IVF. In difficult cases, cervical canal manipulation may be required. Aim : To see if surgical correction of the cervical canal or cervical canal refashioning could improve ease of embryo transfer. Setting : Private infertility and IVF hospital. Design : Prospective study. Materials and Methods : Patients: 11 women with failed 1-3 IVF cycles with history of extremely difficult embryo transfers (ETs despite undergoing cervical dilatation in the cycle prior to IVF. Interventions : Operative hysteroscopy using Versapoint for refashioning of the cervical canal. Main Outcome Measures : Ease of ET in the subsequent IVF cycle. Secondary outcome measure was to assess reproductive outcome. Results : Easy and atraumatic ET in the IVF cycle after procedure in 100% patients. PR was 46.5%. Conclusions : Use of Versapoint for refashioning the cervical canal can improve the quality of ET and PR.

  2. An International Bioinformatics Infrastructure to Underpin the Arabidopsis Community

    Science.gov (United States)

    The future bioinformatics needs of the Arabidopsis community as well as those of other scientific communities that depend on Arabidopsis resources were discussed at a pair of recent meetings held by the Multinational Arabidopsis Steering Committee (MASC) and the North American Arabidopsis Steering C...

  3. Arabidopsis CDS blastp result: AK106750 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK106750 002-115-C09 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  4. Arabidopsis CDS blastp result: AK104851 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104851 001-043-A10 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  5. Arabidopsis CDS blastp result: AK100909 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100909 J023132G24 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylul ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  6. Arabidopsis CDS blastp result: AK058950 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058950 001-020-A07 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  7. Arabidopsis CDS blastp result: AK059821 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059821 006-205-D11 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylu ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  8. Arabidopsis CDS blastp result: AK064944 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064944 J013000P14 At4g15560.1 1-deoxy-D-xylulose 5-phosphate synthase, putative / 1-deoxyxylul ... phate synthase, putative / DXP-synthase, putative (DEF ) (CLA1) identical to SP|Q38854 Probable 1-deoxy-D- ... (DXPS). [Mouse-ear cress] {Arabidopsis thaliana}, DEF ... (def icient in photosynthesis) protein [Arabidopsis ...

  9. Arabidopsis CDS blastp result: AK068400 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK068400 J013151M04 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  10. Arabidopsis CDS blastp result: AK066013 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066013 J013047I12 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  11. Arabidopsis CDS blastp result: AK100241 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100241 J023054P13 At3g45810.1 ferric reductase-like transmembrane component family protein sim ... ilar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  12. Arabidopsis CDS blastp result: AK318553 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK318553 J075145A22 At3g45810.1 68416.m04958 ferric reductase-like transmembrane component famil ... y protein similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ... EMBL:AF055357 [gi:3242789], similar to respiratory burst ... oxidase protein D RbohD from Arabidopsis thaliana, ...

  13. Using "Arabidopsis" Genetic Sequences to Teach Bioinformatics

    Science.gov (United States)

    Zhang, Xiaorong

    2009-01-01

    This article describes a new approach to teaching bioinformatics using "Arabidopsis" genetic sequences. Several open-ended and inquiry-based laboratory exercises have been designed to help students grasp key concepts and gain practical skills in bioinformatics, using "Arabidopsis" leucine-rich repeat receptor-like kinase (LRR RLK) genetic…

  14. Local Auxin Sources Orient the Apical-Basal Axis in Arabidopsis Embryos

    NARCIS (Netherlands)

    Robert, H.S.; Grones, P.; Stepanova, A.N.; Robles, L.M.; Lokerse, A.S.; Alonso, J.M.; Weijers, D.; Friml, J.

    2013-01-01

    Establishment of the embryonic axis foreshadows the main body axis of adults both in plants and in animals, but underlying mechanisms are considered distinct. Plants utilize directional, cell-to-cell transport of the growth hormone auxin [1 and 2] to generate an asymmetric auxin response that specif

  15. WRINKLED1, A Ubiquitous Regulator in Oil Accumulating Tissues from Arabidopsis Embryos to Oil Palm Mesocarp

    OpenAIRE

    Wei Ma; Que Kong; Vincent Arondel; Aruna Kilaru; Bates, Philip D.; Thrower, Nicholas A.; Christoph Benning; Ohlrogge, John B.

    2013-01-01

    Wrinkled1 (AtWRI1) is a key transcription factor in the regulation of plant oil synthesis in seed and non-seed tissues. The structural features of WRI1 important for its function are not well understood. Comparison of WRI1 orthologs across many diverse plant species revealed a conserved 9 bp exon encoding the amino acids "VYL". Site-directed mutagenesis of amino acids within the 'VYL' exon of AtWRI1 failed to restore the full oil content of wri1-1 seeds, providing direct evidence for an essen...

  16. Insight into the early steps of root hair formation revealed by the procuste1 cellulose synthase mutant of Arabidopsis thaliana

    OpenAIRE

    Singh Manoj; Fischer Urs; Singh Sunil K; Grebe Markus; Marchant Alan

    2008-01-01

    Abstract Background Formation of plant root hairs originating from epidermal cells involves selection of a polar initiation site and production of an initial hair bulge which requires local cell wall loosening. In Arabidopsis the polar initiation site is located towards the basal end of epidermal cells. However little is currently understood about the mechanism for the selection of the hair initiation site or the mechanism by which localised hair outgrowth is achieved. The Arabidopsis procust...

  17. Cryopreservation of peach palm zygotic embryos.

    Science.gov (United States)

    Steinmacher, Douglas A; Saldanha, Cleber W; Clement, Charles R; Guerra, Miguel P

    2007-01-01

    Cryopreservation is a safe and cost-effective option for long-term germplasm conservation of non-orthodox seed species, such as peach palm (Bactris gasipaes). The objective of the present study was to establish a cryopreservation protocol for peach palm zygotic embryos based on the encapsulation-dehydration technique. After excision, zygotic embryos were encapsulated with 3 percent sodium alginate plus 2 M glycerol and 0.4 M sucrose, and pre-treated or not with 1 M sucrose during 24 h, followed by air-drying. Fresh weight water contents of beads decreased from 83 percent and 87 percent to 18 percent and 20 percent for pre-treated or non-pretreated beads, respectively, after 4 h of dehydration. Sucrose pre-treatment at 1 M caused lower zygotic embryo germination and plantlet height in contrast to non-treated beads. All the variables were statistically influenced by dehydration time. Optimal conditions for recovery of cryopreserved zygotic embryos include encapsulation and dehydration for 4 h in a forced air cabinet to 20 percent water content, followed by rapid freezing in liquid nitrogen (-196 degree C) and rapid thawing at 45 degree C. In these conditions 29 percent of the zygotic embryos germinated in vitro. However, plantlets obtained from dehydrated zygotic embryos had stunted haustoria and lower heights. Histological analysis showed that haustorium cells were large, vacuolated, with few protein bodies. In contrast, small cells with high nucleus:cytoplasm ratio formed the shoot apical meristem of the embryos, which were the cell types with favorable characteristics for survival after exposure to liquid nitrogen. Plantlets were successfully acclimatized and showed 41+/-9 percent and 88+/-4 percent survival levels after 12 weeks of acclimatization from cryopreserved and non-cryopreserved treatments, respectively. PMID:17369958

  18. Developmental competence of porcine chimeric embryos produced by aggregation

    DEFF Research Database (Denmark)

    Li, Juan; Jakobsen, Jannik E.; Xiong, Qiang;

    2015-01-01

    either by parthenogenetic activation (PA) or handmade cloning (HMC). Results showed that the developmental competence of chimeric embryos, evaluated based on their blastocyst rate and total cell number per blastocyst, was increased when two whole 2-cell stage embryos (PA or HMC) were aggregated. In...... comparison, when two blastomeres were aggregated, the developmental competence of the chimeric embryos decreased if the blastomeres were either from PA or from HMC embryos, but not if they were from different sources, i.e. one PA and one HMC blastomere. To evaluate the cell contribution in embryo formation......The purpose of our study was to compare the developmental competence and blastomere allocation of porcine chimeric embryos formed by micro-well aggregation. Chimeras were created by aggregating either two blastomeres originating from 2-cell embryos or two whole embryos, where embryos were produced...

  19. WOX2 and STIMPY-LIKE/WOX8 promote cotyledon boundary formation in Arabidopsis.

    Science.gov (United States)

    Lie, Catharine; Kelsom, Corey; Wu, Xuelin

    2012-11-01

    One of the key events in dicot plant embryogenesis is the emergence of the two cotyledon primordia, which marks the transition from radial symmetry to bilateral symmetry. In Arabidopsis thaliana, the three CUP-SHAPED COTYLEDON (CUC) genes are responsible for determining the boundary region between the cotyledons. However, the mechanisms controlling their transcription activation are not well understood. Previous studies found that several WOX family homeobox transcription factors are involved in embryo apical patterning and cotyledon development. Here we show that WOX2 and STIMPY-LIKE (STPL/WOX8) act redundantly to differentially regulate the expression of the CUC genes in promoting the establishment of the cotyledon boundary, without affecting the primary shoot meristem. Loss of both WOX2 and STPL results in reduced CUC2 and CUC3 expression in one side of the embryo, but an expansion of the CUC1 domain. Furthermore, we found that STPL is expressed in the embryo proper, and its activation is enhanced by the removal of WOX2, providing an explanation for the functional redundancy between WOX2 and STPL. Additional evidence also showed that WOX2 and STPL function independently in regulating different aspects of local auxin gradient formation during early embryogenesis. PMID:22827849

  20. Sterol Methyl Oxidases Affect Embryo Development via Auxin-Associated Mechanisms.

    Science.gov (United States)

    Zhang, Xia; Sun, Shuangli; Nie, Xiang; Boutté, Yohann; Grison, Magali; Li, Panpan; Kuang, Susu; Men, Shuzhen

    2016-05-01

    Sterols are essential molecules for multiple biological processes, including embryogenesis, cell elongation, and endocytosis. The plant sterol biosynthetic pathway is unique in the involvement of two distinct sterol 4α-methyl oxidase (SMO) families, SMO1 and SMO2, which contain three and two isoforms, respectively, and are involved in sequential removal of the two methyl groups at C-4. In this study, we characterized the biological functions of members of the SMO2 gene family. SMO2-1 was strongly expressed in most tissues during Arabidopsis (Arabidopsis thaliana) development, whereas SMO2-2 showed a more specific expression pattern. Although single smo2 mutants displayed no obvious phenotype, the smo2-1 smo2-2 double mutant was embryonic lethal, and the smo2-1 smo2-2/+ mutant was dwarf, whereas the smo2-1/+ smo2-2 mutant exhibited a moderate phenotype. The phenotypes of the smo2 mutants resembled those of auxin-defective mutants. Indeed, the expression of DR5rev:GFP, an auxin-responsive reporter, was reduced and abnormal in smo2-1 smo2-2 embryos. Furthermore, the expression and subcellular localization of the PIN1 auxin efflux facilitator also were altered. Consistent with these observations, either the exogenous application of auxin or endogenous auxin overproduction (YUCCA9 overexpression) partially rescued the smo2-1 smo2-2 embryonic lethality. Surprisingly, the dwarf phenotype of smo2-1 smo2-2/+ was completely rescued by YUCCA9 overexpression. Gas chromatography-mass spectrometry analysis revealed a substantial accumulation of 4α-methylsterols, substrates of SMO2, in smo2 heterozygous double mutants. Together, our data suggest that SMO2s are important for correct sterol composition and function partially through effects on auxin accumulation, auxin response, and PIN1 expression to regulate Arabidopsis embryogenesis and postembryonic development. PMID:27006488

  1. Allele-specific virulence attenuation of the Pseudomonas syringae HopZ1a type III effector via the Arabidopsis ZAR1 resistance protein.

    Directory of Open Access Journals (Sweden)

    Jennifer D Lewis

    2010-04-01

    Full Text Available Plant resistance (R proteins provide a robust surveillance system to defend against potential pathogens. Despite their importance in plant innate immunity, relatively few of the approximately 170 R proteins in Arabidopsis have well-characterized resistance specificity. In order to identify the R protein responsible for recognition of the Pseudomonas syringae type III secreted effector (T3SE HopZ1a, we assembled an Arabidopsis R gene T-DNA Insertion Collection (ARTIC from publicly available Arabidopsis thaliana insertion lines and screened it for plants lacking HopZ1a-induced immunity. This reverse genetic screen revealed that the Arabidopsis R protein HOPZ-activated resistance 1 (ZAR1; At3g50950 is required for recognition of HopZ1a in Arabidopsis. ZAR1 belongs to the coiled-coil (CC class of nucleotide binding site and leucine-rich repeat (NBS-LRR containing R proteins; however, the ZAR1 CC domain phylogenetically clusters in a clade distinct from other related Arabidopsis R proteins. ZAR1-mediated immunity is independent of several genes required by other R protein signaling pathways, including NDR1 and RAR1, suggesting that ZAR1 possesses distinct signaling requirements. The closely-related T3SE protein, HopZ1b, is still recognized by zar1 Arabidopsis plants indicating that Arabidopsis has evolved at least two independent R proteins to recognize the HopZ T3SE family. Also, in Arabidopsis zar1 plants HopZ1a promotes P. syringae growth indicative of an ancestral virulence function for this T3SE prior to the evolution of recognition by the host resistance protein ZAR1. Our results demonstrate that the Arabidopsis resistance protein ZAR1 confers allele-specific recognition and virulence attenuation of the Pseudomonas syringae T3SE protein HopZ1a.

  2. Assay using embryo aggregation chimeras for the detection of nonlethal changes in X-irradiated mouse preimplantation embryos

    International Nuclear Information System (INIS)

    We have developed a short-term in vitro assay for the detection of sublethal effects produced by very low levels of ionizing radiation. The assay utilizes mouse embryo aggregation chimeras consisting of one irradiated embryo paired with an unirradiated embryo whose blastomeres have been labeled with fluorescein isothiocyanate (FITC). X irradiation (from 0.05 to 2 Gy) and chimera construction were performed with four-cell stage embryos, and the chimeras were cultured for 40 h to the morula stage. The morulae were partially dissociated with calcium-free culture medium and viewed under phase contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution of irradiated (unlabeled) and control (FITC labeled) embryos per chimera. In chimeras where neither embryo was irradiated, the ratio of the unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.50 (17.8 +/- 5.6 cells per unlabeled embryo and 17.4 +/- 5.5 cells per FITC-labeled partner embryo). However, in chimeras formed after the unlabeled embryos were irradiated with as little as 0.05 Gy, the ratio of unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.43 (P less than 0.01). The apparent decreases in cell proliferation were not observed in irradiated embryos that were merely cocultured with control embryos, regardless of whether the embryos were zona enclosed or zona free. We conclude that very low levels of radiation induce sublethal changes in cleaving embryos that are expressed as a proliferative disadvantage within two cell cycles when irradiated embryos are in direct cell-to-cell contact with unirradiated embryos

  3. Thermal manipulations of turkey embryos: The effect on thermoregulation and development during embryogenesis.

    Science.gov (United States)

    Piestun, Y; Zimmerman, I; Yahav, S

    2015-02-01

    Previous studies conducted on meat-type chickens in our laboratory showed that thermal manipulations (TMS:) of the embryo during the time window of the hypothalamus-hypophysis-thyroid axis development and maturation significantly reduced the metabolic rates of the embryo and the chicken, improving the posthatch feed conversion rate (FCR:). The aim of the present study was to investigate the effect of intermittent TMs during turkey embryogenesis on embryo development. Fertile turkey eggs were divided into three treatments: control; 6H--with TM by elevation of temperature and RH by 1.7°C and 9%, respectively, above the control conditions for 6 h/d, from E10 through E22, i.e., 240 through 552 h of incubation; and 12H--with TM as above, for 12 h/d, during the same time period. From E0 through E10 and from E23 onward all eggs were incubated under control conditions. The embryo growth rate was not negatively affected by TM. During TM eggshell temperature, the embryonic heart rate and oxygen consumption were elevated by the manipulation while the embryos were in their ectothermic phase. However, by the end of the TM period and until hatch (the endothermic phase) these parameters were significantly lower in both TM treatments than in the control, indicating a lower metabolic rate and heat production. The TM embryos hatched approximately 10 h earlier than the controls, without any negative effects on chick body weight or hatchability. Nevertheless, TM treatments resulted in a higher proportion of chicks with unhealed navels. Body temperature at hatch was significantly lower in the TM chicks than in the controls, suggesting lower heat production and metabolic rate, which might affect the energy requirements for posthatch maintenance. It was concluded that TM during turkey embryogenesis might have altered the thermoregulatory set point, and thus lowered the embryo metabolic rate, which might have a long-lasting posthatch effect. PMID:25630674

  4. Human embryos in the original position?

    Science.gov (United States)

    DiSilvestro, Russell

    2005-06-01

    Two different discussions in John Rawls' A Theory of Justice lead naturally to a rather conservative position on the moral status of the human embryo. When discussing paternalism, he claims that the parties in the original position would seek to protect themselves in case they end up as incapacitated or undeveloped human beings when the veil of ignorance is lifted. Since human embryos are examples of such beings, the parties in the original position would seek to protect themselves from their embryonic stages onward. When discussing the basis of equality, Rawls claims that the parties in the original position would guarantee basic rights for all those with the capacity to take part in this original position. To guarantee the basic rights of infants and young children, he goes on to interpret this capacity as a "potentiality that is ordinarily realized in due course." Since human embryos have this potentiality, they too should have basic rights. PMID:16036460

  5. Embryo aggregation does not improve the development of interspecies somatic cell nuclear transfer embryos in the horse.

    Science.gov (United States)

    Gambini, Andrés; De Stéfano, Adrián; Jarazo, Javier; Buemo, Carla; Karlanian, Florencia; Salamone, Daniel Felipe

    2016-09-01

    The low efficiency of interspecies somatic cell nuclear transfer (iSCNT) makes it necessary to investigate new strategies to improve embryonic developmental competence. Embryo aggregation has been successfully applied to improve cloning efficiency in mammals, but it remains unclear whether it could also be beneficial for iSCNT. In this study, we first compared the effect of embryo aggregation over in vitro development and blastocyst quality of porcine, bovine, and feline zona-free (ZF) parthenogenetic (PA) embryos to test the effects of embryo aggregation on species that were later used as enucleated oocytes donors in our iSCNT study. We then assessed whether embryo aggregation could improve the in vitro development of ZF equine iSCNT embryos after reconstruction with porcine, bovine, and feline ooplasm. Bovine- and porcine-aggregated PA blastocysts had significantly larger diameters compared with nonaggregated embryos. On the other hand, feline- and bovine-aggregated PA embryos had higher blastocyst cell number. Embryo aggregation of equine-equine SCNT was found to be beneficial for embryo development as we have previously reported, but the aggregation of three ZF reconstructed embryos did not improve embryo developmental rates on iSCNT. In vitro embryo development of nonaggregated iSCNT was predominantly arrested around the stage when transcriptional activation of the embryonic genome is reported to start on the embryo of the donor species. Nevertheless, independent of embryo aggregation, equine blastocyst-like structures could be obtained in our study using domestic feline-enucleated oocytes. Taken together, these results reported that embryo aggregation enhance in vitro PA embryo development and embryo quality but effects vary depending on the species. Embryo aggregation also improves, as expected, the in vitro embryo development of equine-equine SCNT embryos; however, we did not observe positive effects on equine iSCNT embryo development. Among oocytes

  6. Survival of embryo irradiated with gamma rays by embryo culture in Brassica pekinensis Rupr

    International Nuclear Information System (INIS)

    The effect of irradiation on the survival rates and embryonic development of Brassica pekinensis RUPR. (Varieties; Kashin, Kohai 65 nichi and kairyochitose) was investigated. The purpose of this study was to seek ways of increasing the survival rates of embryos such as B.oleracea obtained through embryo culture techniques after irradiation doses affecting seed fertility and germination, for the purpose of increasing mutation rates. Embryos at different developmental stages ranging from the globular to the early heart stages were irradiated with 20 KR of gamma rays at the daily rate 0L 20 KR or 10 KR (Fig.1 and Table 1). The embryos were excised from ovules 4 to 10 days after irradiation and cultured on White's medium. The shooting and rooting rates on the 34th day of culture were higher at the dose of 10 KR/day than 20 KR/day and were lower when the materials were irradiated at the young embryonic stage (Table 3). Varietal differences in the shooting and rooting rates were also observed. The irradiated embryos survived mainly in the state of callus. It was concluded that the embryo culture technique was successful when applied to irradiated embryos excised at the young embryonic stage and that the technique affected B.pekinensis less than B.oleracea

  7. Migration and Growth of Protoplanetary Embryos. I. Convergence of Embryos in Protoplanetary Disks

    Science.gov (United States)

    Zhang, Xiaojia; Liu, Beibei; Lin, Douglas N. C.; Li, Hui

    2014-12-01

    According to the core accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses (Mp ) in the range of a few Earth masses (M ⊕) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When Mp > 10 M ⊕, embryos efficiently accrete gas and evolve into cores of gas giants. We use a numerical simulation to show that despite stream line interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torques by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in their mutual mean motion resonances and form a convoy of super-Earths. In more massive disks, they could overcome these resonant barriers to undergo repeated close encounters, including cohesive collisions that enable the formation of massive cores.

  8. Interspecific hybridization of Trifolium repens with T. hybridum using in ovulo embryo and embryo culture

    International Nuclear Information System (INIS)

    In ovulo embryo culture followed by culture of excised immature embryos produced interspecific hybrids between Trifolium repens L. (white clover) and autotetraploid T. hybridum L. (alsike clover). Ovules containing hybrid embryos were excised 12–14 d after pollination and cultured on Nitsch (1951) medium supplemented with 15% young cucumber juice for 5–6 d. Embryos were subsequently excised and transferred to hormone-free EG medium, a medium suitable for the culture of immature embryos. A total of 118 hybrid seedlings were obtained from 1978 reciprocal pollinations. All seedlings produced showed various chlorophyll deficiencies, either totally albino or albino with green sectors. Transmission electron microscope studies were carried out to investigate plastid development in embryos and seedlings. Some embryos produced only callus. Plants were regenerated from seven calli. Two semi-albino plants survived transfer to soil, and one plant produced flowers. Backcrosses to T. repens produced one green plant. Hybridity is supported by analysis of morphological characters, karyotype and the gel electrophoretic separation of leaf isozymes. Pollen irradiated with 40 Gy of gamma rays was also used for pollinations. Results indicate that in certain cases ionizing radiation might be useful in overcoming hybrid inviability. (author)

  9. RECYCLING OF CATHETER FOR EMBRYO RECOVERY: A TOOL FOR COSTS REDUCTION IN EQUINE EMBRYO TRANSFER

    Directory of Open Access Journals (Sweden)

    Alberto Lopes Gusmao

    2010-06-01

    Full Text Available The embryo transfer is becoming a widespread practice.Most embryos are collected from spontaneous single ovulatingmares and result in 50% of embryo recovery, increasing the costsof production. To illustrate, the price of a catheter for embryosrecovery range from US$ 194.00 to US$ 250.00 (R$ 350.00 to R$450.00. Therefore, the aim of this work was to verify if catheterwith damaged balloon can be recuperated and reused withoutaltering its efficiency. For this study, two groups were used: acontrol group (GI, n=10, on which the nonsurgical recovery of theembryos of mares was performed with the catheter with originalballoon; and another group (GII, n=20, in which a restored catheterwas utilized. The mares of GI had an embryo recovery rate of60%, and GII mares had an embryo recovery rate of 55%. Therewas not statistical difference between groups I and II (P>0.05.Considering that the material used to restore the catheter costsUS$16.66 (R$30.00, this data show that the recuperation of thecatheters for embryo recovery in mares may reduce costs withoutcompromising the rates of embryo recovery.

  10. Migration and growth of protoplanetary embryos. I. Convergence of embryos in protoplanetary disks

    International Nuclear Information System (INIS)

    According to the core accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses (Mp ) in the range of a few Earth masses (M ⊕) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When Mp > 10 M ⊕, embryos efficiently accrete gas and evolve into cores of gas giants. We use a numerical simulation to show that despite stream line interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torques by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in their mutual mean motion resonances and form a convoy of super-Earths. In more massive disks, they could overcome these resonant barriers to undergo repeated close encounters, including cohesive collisions that enable the formation of massive cores.

  11. Migration and growth of protoplanetary embryos. I. Convergence of embryos in protoplanetary disks

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaojia; Lin, Douglas N. C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Liu, Beibei [Kavli Institute for Astronomy and Astrophysics and Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Li, Hui, E-mail: xzhang47@ucsc.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-12-10

    According to the core accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses (M{sub p} ) in the range of a few Earth masses (M {sub ⊕}) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When M{sub p} > 10 M {sub ⊕}, embryos efficiently accrete gas and evolve into cores of gas giants. We use a numerical simulation to show that despite stream line interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torques by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in their mutual mean motion resonances and form a convoy of super-Earths. In more massive disks, they could overcome these resonant barriers to undergo repeated close encounters, including cohesive collisions that enable the formation of massive cores.

  12. Functional Analysis of Arabidopsis Sucrose Transporters

    Energy Technology Data Exchange (ETDEWEB)

    John M. Ward

    2009-03-31

    Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.

  13. Nano-nutrition of chicken embryos

    DEFF Research Database (Denmark)

    Sawosz, Filip; Pineda, Lane Manalili; Hotowy, Anna;

    2013-01-01

    post-hatch mortality and skeletal disorders and increases muscle growth and breast meat yield. Adenosine triphosphate (ATP) is a "ready for use" energetic molecule, while nanoparticles of silver (Nano-Ag) may penetrate tissues as well as cells and localise inside cells. In this investigation, we...... broiler eggs was randomly divided into a Control group without injection and injected groups with hydrocolloids of Nano-Ag, ATP or a complex of Nano-Ag and ATP (Nano-Ag/ATP). The embryos were evaluated on day 20 of incubation. The results indicate that the application of ATP to chicken embryos increases...

  14. Brave new propagules: terrestrial embryos in anamniotic eggs.

    Science.gov (United States)

    Martin, K L; Carter, A L

    2013-08-01

    A surprisingly large number of fish and amphibian species reproduce terrestrially despite the absence of the key evolutionary innovation of the amniotic egg. In contrast with shelled eggs of reptiles and birds, eggs of teleost fish and amphibians are typically much smaller and enclosed in relatively simple chorionic membranes. Incubation times may be brief or prolonged, and resultant hatchlings typically require the return to an aquatic habitat. Advantages of terrestrial incubation include the increased availability of warmer temperatures and avoidance of aquatic hypoxia, whereas disadvantages include desiccation, exposure to novel predators, and the risk of hatching into a hostile habitat. Hatching may be environmentally cued. Use of energy in the yolk may require trade-offs between growth of the embryo and extended incubation, as exemplified by a case study of the California Grunion. The physical challenges of terrestrial incubation, constraints for hatching, effects of egg size, and parental care are explored. Eight different types of early life history among anamniotic embryos incubating in a terrestrial environment are identified, with examples of these alternate routes to the invasion of land by vertebrates. PMID:23604618

  15. Changes in oscillatory dynamics in the cell cycle of early Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    Tony Y-C Tsai

    2014-02-01

    Full Text Available During the early development of Xenopus laevis embryos, the first mitotic cell cycle is long (∼85 min and the subsequent 11 cycles are short (∼30 min and clock-like. Here we address the question of how the Cdk1 cell cycle oscillator changes between these two modes of operation. We found that the change can be attributed to an alteration in the balance between Wee1/Myt1 and Cdc25. The change in balance converts a circuit that acts like a positive-plus-negative feedback oscillator, with spikes of Cdk1 activation, to one that acts like a negative-feedback-only oscillator, with a shorter period and smoothly varying Cdk1 activity. Shortening the first cycle, by treating embryos with the Wee1A/Myt1 inhibitor PD0166285, resulted in a dramatic reduction in embryo viability, and restoring the length of the first cycle in inhibitor-treated embryos with low doses of cycloheximide partially rescued viability. Computations with an experimentally parameterized mathematical model show that modest changes in the Wee1/Cdc25 ratio can account for the observed qualitative changes in the cell cycle. The high ratio in the first cycle allows the period to be long and tunable, and decreasing the ratio in the subsequent cycles allows the oscillator to run at a maximal speed. Thus, the embryo rewires its feedback regulation to meet two different developmental requirements during early development.

  16. An integrated platform for large-scale data collection and precise perturbation of live Drosophila embryos

    Science.gov (United States)

    Levario, Thomas J.; Zhao, Charles; Rouse, Tel; Shvartsman, Stanislav Y.; Lu, Hang

    2016-02-01

    Understanding the fundamental principles governing embryogenesis is a key goal of developmental biology. Direct observation of embryogenesis via in vivo live imaging is vital to understanding embryogenesis; yet, tedious sample preparation makes it difficult to acquire large-scale imaging data that is often required to overcome experimental and biological noises for quantitative studies. Furthermore, it is often difficult, and sometimes impossible, to incorporate environmental perturbation for understanding developmental responses to external stimuli. To address this issue, we have developed a method for high-throughput imaging of live embryos, delivering precise environmental perturbations, and unbiased data extraction. This platform includes an optimized microfluidic device specifically for live embryos and also for precise perturbations in the microenvironment of the developing embryos. In addition, we developed software for simple, yet accurate, automated segmentation of fluorescent images, and automated data extraction. Using a quantitative assessment we find that embryos develop normally within the microfluidic device. Finally, we show an application of the high-throughput assay for monitoring developmental responses to external stimuli: anoxia-induced developmental arrest in Drosophila embryos. With slight modifications, the method developed in this work can be applied to many other models of development and other stimulus-response behaviors during development.

  17. Generation of Parabiotic Zebrafish Embryos by Surgical Fusion of Developing Blastulae.

    Science.gov (United States)

    Hagedorn, Elliott J; Cillis, Jennifer L; Curley, Caitlyn R; Patch, Taylor C; Li, Brian; Blaser, Bradley W; Riquelme, Raquel; Zon, Leonard I; Shah, Dhvanit I

    2016-01-01

    Surgical parabiosis of two animals of different genetic backgrounds creates a unique scenario to study cell-intrinsic versus cell-extrinsic roles for candidate genes of interest, migratory behaviors of cells, and secreted signals in distinct genetic settings. Because parabiotic animals share a common circulation, any blood or blood-borne factor from one animal will be exchanged with its partner and vice versa. Thus, cells and molecular factors derived from one genetic background can be studied in the context of a second genetic background. Parabiosis of adult mice has been  used extensively to research aging, cancer, diabetes, obesity, and brain development. More recently, parabiosis of zebrafish embryos has been used to study the developmental biology of hematopoiesis. In contrast to mice, the transparent nature of zebrafish embryos permits the direct visualization of cells in the parabiotic context, making it a uniquely powerful method for investigating fundamental cellular and molecular mechanisms. The utility of this technique, however, is limited by a steep learning curve for generating the parabiotic zebrafish embryos. This protocol provides a step-by-step method on how to surgically fuse the blastulae of two zebrafish embryos of different genetic backgrounds to investigate the role of candidate genes of interest. In addition, the parabiotic zebrafish embryos are tolerant to heat shock, making temporal control of gene expression possible. This method does not require a sophisticated set-up and has broad applications for studying cell migration, fate specification, and differentiation in vivo during embryonic development. PMID:27341538

  18. Endogenous electric fields in embryos during development, regeneration and wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Nuccitelli, R

    2003-07-01

    All embryos that have been investigated drive ionic currents through themselves and these currents will generate internal electric fields. Here, those examples in which such fields have been measured directly are discussed. The first such measurements were made in chick embryos and about 20 mV mm-1 was measured near the posterier intestinal portal in 2-4-day-old embryos. This electric field is important for the development of tail structures because reducing its magnitude results in abnormal tail development. The second embryonic electric field measured directly was in the axolotl, where a rostral-caudal field of about the same magnitude was detected. Modification of this field during neurulation but not gastrulation caused developmental abnormalities. Most recently, the development of left-right asymmetry in frog and chick embryos was found to require a voltage difference between blastomeres at a very early developmental stage. This field was measured in the chick embryo to be 10-20 mV mm-1 across the primitive streak. Mammalian skin wounds generate 150 mV mm-1 fields lateral to the wound and corneal epidermal wounds exhibit lateral fields of 40 mV mm-1. The presence of these endogenous fields would suggest that exposures to external electric fields should be limited to magnitudes of less than 0.1 V m-1. (author)

  19. Embryo transfer and related technologies in sheep reproduction

    OpenAIRE

    Loi, Pasqualino; Ptak, Grazyna; Dattena, Maria; Ledda, Sergio; Naitana, Salvatore; Cappai, Pietro

    1998-01-01

    This paper reviews the status of embryo transfer and the major technologies applied to preimplantation of embryos in sheep. Embryo production from superovulated ewes is hindered by an unpredictable response to hormonal treatment. Progress in this area should be expected by an appropriated control of follicular development with gonadotropin-releasing hormone (GnRH) agonist or antagonist prior to gonadotrophin administration. Simple protocols for the cryopreservation of sheep embryos by vitrifi...

  20. Is embryo transfer a useful technique for small community farmers?

    International Nuclear Information System (INIS)

    Four main aspects of embryo technology are dealt with in this paper. The first analyses the reasons for the poor selection of recipients for embryo transfer, the second relates to inaccurate evaluation of embryos at least under tropical conditions, the third proposes alternative methods to evaluate embryos for selection and freezing, and the fourth analyses the feasibility of establishing this technique as a biotechnology approach for improving production in small community tropical farms. (author)

  1. Sourcing human embryos for embryonic stem cell lines: Problems & perspectives

    Directory of Open Access Journals (Sweden)

    Rajvi H Mehta

    2014-01-01

    Full Text Available The ability to successfully derive human embryonic stem cells (hESC lines from human embryos following in vitro fertilization (IVF opened up a plethora of potential applications of this technique. These cell lines could have been successfully used to increase our understanding of human developmental biology, transplantation medicine and the emerging science of regenerative medicine. The main source for human embryos has been ′discarded′ or ′spare′ fresh or frozen human embryos following IVF. It is a common practice to stimulate the ovaries of women undergoing any of the assisted reproductive technologies (ART and retrieve multiple oocytes which subsequently lead to multiple embryos. Of these, only two or maximum of three embryos are transferred while the rest are cryopreserved as per the decision of the couple. In case a couple does not desire to ′cryopreserve′ their embryos then all the embryos remaining following embryo transfer can be considered ′spare′ or if a couple is no longer in need of the ′cryopreserved′ embryos then these also can be considered as ′spare′. But, the question raised by the ethicists is, "what about ′slightly′ over-stimulating a woman to get a few extra eggs and embryos? The decision becomes more difficult when it comes to ′discarded′ embryos. As of today, the quality of the embryos is primarily assessed based on morphology and the rate of development mainly judged by single point assessment. Despite many criteria described in the literature, the quality assessment is purely subjective. The question that arises is on the decision of ′discarding′ embryos. What would be the criteria for discarding embryos and the potential ′use′ of ESC derived from the ′abnormal appearing′ embryos? This paper discusses some of the newer methods to procure embryos for the derivation of embryonic stem cell lines which will respect the ethical concerns but still provide the source material.

  2. Planetary Embryo Bow Shocks as a Mechanism for Chondrule Formation

    OpenAIRE

    Mann, Christopher R.; Boley, Aaron C.; Morris, Melissa M.

    2016-01-01

    We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary embryo traveling on a moderately excited orbit through the dusty, early environment of the solar system. The embryo's eccentric orbit produces a range of supersonic relative velocities between the embryo and the circularly orbiting gas and dust, prompting t...

  3. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    OpenAIRE

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2015-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C...

  4. Membrane association of the Arabidopsis ARF exchange factor GNOM involves interaction of conserved domains

    DEFF Research Database (Denmark)

    Anders, Nadine; Nielsen, Michael M.; Keicher, Jutta;

    2008-01-01

    The GNOM protein plays a fundamental role in Arabidopsis thaliana development by regulating endosome-to-plasma membrane trafficking required for polar localization of the auxin efflux carrier PIN1. GNOM is a family member of large ARF guanine nucleotide exchange factors (ARF-GEFs), which regulate...

  5. 3D fluorescent in situ hybridization using Arabidopsis leaf cryosections and isolated nuclei

    Directory of Open Access Journals (Sweden)

    Biot Eric

    2009-08-01

    Full Text Available Abstract Background Fluorescent hybridization techniques are widely used to study the functional organization of different compartments within the mammalian nucleus. However, few examples of such studies are known in the plant kingdom. Indeed, preservation of nuclei 3D structure, which is required for nuclear organization studies, is difficult to fulfill. Results We report a rapid protocol for fluorescent in situ hybridization (FISH performed on 3D isolated nuclei and thin cryosectioned leaves of Arabidopsis thaliana. The use of direct labeling minimized treatment steps, shortening the overall procedure. Using image analysis, we measured different parameters related to nucleus morphology and overall 3D structure. Conclusion Our work describes a 3D-FISH protocol that preserves the 3D structure of Arabidopsis interphase nuclei. Moreover, we report for the first time FISH using cryosections of Arabidopsis leaves. This protocol is a valuable tool to investigate nuclear architecture and chromatin organization.

  6. Ectopic overexpression of castor bean LEAFY COTYLEDON2 (LEC2) in Arabidopsis triggers the expression of genes that encode regulators of seed maturation and oil body proteins in vegetative tissues ☆

    OpenAIRE

    Hyun Uk Kim; Su-Jin Jung; Kyeong-Ryeol Lee; Eun Ha Kim; Sang-Min Lee; Kyung Hee Roh; Jong-Bum Kim

    2013-01-01

    The LEAFY COTYLEDON2 (LEC2) gene plays critically important regulatory roles during both early and late embryonic development. Here, we report the identification of the LEC2 gene from the castor bean plant (Ricinus communis), and characterize the effects of its overexpression on gene regulation and lipid metabolism in transgenic Arabidopsis plants. LEC2 exists as a single-copy gene in castor bean, is expressed predominantly in embryos, and encodes a protein with a conserved B3 domain, but dif...

  7. Deciding the fate of disputed embryos: ethical issues in the case of Natallie Evans

    Science.gov (United States)

    Smajdor, Anna

    2007-01-01

    Background A number of disputes have arisen in recent years over the status of non-transferred embryos cryopreserved during in vitro fertilisation. One such case is that of Natallie Evans who in April 2007 lost her final attempt to prevent the destruction of embryos created with the sperm of her former partner. Ms Evans had been rendered infertile by cancer treatment, and the embryos represented her only chance of having genetically related children. Discussion Arguments over stored embryos often conflate different concepts of parenthood. The effects of 'forcing' genetic parenthood on a man are mistakenly presented as being analogous with forcing women to bear children. Likewise, there is a tendency to assume that genetic parenthood necessarily involves legal, financial and psychological implications. Men (or women) who object to becoming parents should be encouraged to specify which aspects of parenthood they regard as being harmful. While the financial or physical burdens of forced parenthood involve objective harms, the putative psychological harms of enforced genetic parenthood are subjective, and this distinction should be recognised. Popular beliefs about genetic parenthood perpetuate the kinds of subjective concerns expressed by Ms Evans' partner, but the concept of genetic parenthood itself may come under pressure in the face of future technological developments. Summary Historical legal requirements obliging men to provide for their genetic offspring still pervade in the law. These perceptions are becoming outmoded in context of rapidly-moving reproductive technologies. To avoid disputes greater flexibility is required. The economic and legal components of parenthood should be negotiable in cases where disputes arise, and should not be assumed to flow inexorably from genetic paternity. To reduce the chances of disputes arising, consent protocols for cryopreservation of non-transferred embryos should be refined. Couples should address the possibility of

  8. Cell-cell interactions determine the dorsoventral axis in embryos of an equally cleaving opisthobranch mollusc.

    Science.gov (United States)

    Boring, L

    1989-11-01

    Dorsoventral polarity in molluscan embryos can arise by two distinct mechanisms, where the mechanism employed is strongly correlated with the cleavage pattern of the early embryo. In species with unequal cleavage, the dorsal lineage, or "D quadrant", is determined in a cell-autonomous manner by the inheritance of cytoplasmic determinants. However, in gastropod molluscs with equal cleavage, cell-cell interactions are required to specify the fate of the dorsal blastomere. During the fifth cleavage interval in equally cleaving embryos, one of the vegetal macromeres makes exclusive contacts with the animal micromeres, and this macromere will give rise to the mesodermal precursor cell at the next division, thereby identifying the dorsal quadrant. This study examines D-quadrant determination in an equally cleaving species from a group of previously uninvestigated gastropods, the subclass Opisthobranchia. Blastomere ablation experiments were performed on embryos of Haminoea callidegenita to (i) determine the developmental potential of macromeres before and after fifth cleavage, and (ii) examine the role of micromere-macromere interactions in the establishment of bilateral symmetry. The results suggest that the macromeres are developmentally equivalent prior to fifth cleavage, but become nonequivalent soon afterward. The dorsoventral axis corresponds to the displacement of the micromeres over one macromere early in the fifth cleavage interval. This unusual cellular topology is hypothesized to result from constraints imposed on micromere-macromere interactions in an embryo that develops from a large egg and forms a stereoblastula (no cleavage cavity). Ablation of the entire first quarter of micromeres results in embryos which remain radially symmetrical in the vegetal hemisphere, indicating that micromere-macromere interactions are required for the elaboration of bilateral symmetry properties. Therefore, inductive interactions between cells may represent a general strategy

  9. Culture of Cells from Amphibian Embryos.

    Science.gov (United States)

    Stanisstreet, Martin

    1983-01-01

    Describes a method for in vitro culturing of cells from amphibian early embryos. Such cells can be used to demonstrate such properties of eukaryote cells as cell motility, adhesion, differentiation, and cell sorting into tissues. The technique may be extended to investigate other factors. (Author/JN)

  10. Triploid-diploid mosaic chicken embryo.

    Science.gov (United States)

    Bloom, S E; Buss, E G

    1966-08-12

    Cytological analysis of an underdeveloped chicken embryo at 6 days of incubation revealed a triploid-diploid mosaic condition. Of the 30 metaphases observed, 19 were triploid and 11 diploid. The triploid cells were 3A-ZZZ and diploid cells 2A-ZZ, as determined for the six largest pairs of chromnosomes. PMID:5328678

  11. Effects of Fluoxetine on Human Embryo Development

    NARCIS (Netherlands)

    Kaihola, Helena; Yaldir, Fatma G.; Hreinsson, Julius; Hornaeus, Katarina; Bergquist, Jonas; Olivier, Jocelien D. A.; Akerud, Helena; Sundstrom-Poromaa, Inger

    2016-01-01

    The use of antidepressant treatment during pregnancy is increasing, and selective serotonin reuptake inhibitors (SSRIs) are the most widely prescribed antidepressants in pregnant women. Serotonin plays a role in embryogenesis, and serotonin transporters are expressed in two-cell mouse embryos. Thus,

  12. Arabidopsis CDS blastp result: AK119708 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119708 002-157-E08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  13. Arabidopsis CDS blastp result: AK060981 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060981 006-202-H08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  14. Arabidopsis CDS blastp result: AK111736 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111736 J023047L09 At1g68370.1 gravity -responsive protein / altered response to gravity ... protein ... (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  15. Arabidopsis CDS blastp result: AK070093 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK070093 J023041M10 At2g39290.1 phosphatidylglycerolphosphate synthase (PGS1) identical to phosphati...dylglycerolphosphate synthase GI:13365519 from [Arabidopsis thaliana] 7e-78 ...

  16. Arabidopsis CDS blastp result: AK060009 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060009 006-302-D03 At2g39290.1 phosphatidylglycerolphosphate synthase (PGS1) identical to phosphati...dylglycerolphosphate synthase GI:13365519 from [Arabidopsis thaliana] 8e-71 ...

  17. Arabidopsis CDS blastp result: AK058419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058419 001-015-D06 At4g16280.3 flowering time ... control protein / FCA gamma (FCA) identical to S ... P|O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  18. Arabidopsis CDS blastp result: AK073225 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK073225 J033023C04 At4g16280.3 flowering time ... control protein / FCA gamma (FCA) identical to SP ... |O04425 Flowering time ... control protein FCA {Arabidopsis thaliana}; four a ...

  19. Arabidopsis CDS blastp result: AK102695 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102695 J033103F21 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  20. Arabidopsis CDS blastp result: AK102134 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102134 J033085F12 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  1. Arabidopsis CDS blastp result: AK066835 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066835 J013087I16 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-171 ...

  2. Arabidopsis CDS blastp result: AK065259 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK065259 J013002J18 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  3. Arabidopsis CDS blastp result: AK100523 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100523 J023100P04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  4. Arabidopsis CDS blastp result: AK288065 [KOME

    Lifescience Database Archive (English)

    Full Text Available al to sulfate tansporter Sultr1;3 [Arabidopsis thaliana] GI:10716805; contains Pfam profile PF00916: Sulfate... transporter family; contains Pfam profile PF01740: STAS domain; contains TIGRfam profile TIGR00815: sulfate permease 1e-145 ...

  5. Arabidopsis CDS blastp result: AK288002 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288002 J075110B01 At1g68510.1 68414.m07826 LOB domain protein 42 ... / lateral organ boundaries do ... main protein 42 ... (LBD42 ) identical to LOB DOMAIN 42 ... [Arabidopsis th ...

  6. Arabidopsis CDS blastp result: AK241043 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 2e-41 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  7. Arabidopsis CDS blastp result: AK243135 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 7e-43 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  8. Arabidopsis CDS blastp result: AK111785 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111785 J023089N11 At5g62310.1 incomplete root hair ... elongation (IRE) / protein kinase, putative ... nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  9. Arabidopsis CDS blastp result: AK243050 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243050 J100011E04 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  10. Arabidopsis CDS blastp result: AK242758 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242758 J090051H03 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  11. Arabidopsis CDS blastp result: AK242717 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242717 J090043H19 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  12. Arabidopsis CDS blastp result: AK288095 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288095 J075191E21 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  13. Arabidopsis CDS blastp result: AK242638 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242638 J090023J02 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  14. Arabidopsis CDS blastp result: AK242651 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242651 J090026B08 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  15. Arabidopsis CDS blastp result: AK287631 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287631 J065073J24 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  16. Arabidopsis CDS blastp result: AK288923 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288923 J090081P06 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  17. Arabidopsis CDS blastp result: AK242271 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242271 J075187A19 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  18. Arabidopsis CDS blastp result: AK242681 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242681 J090032N04 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  19. Arabidopsis CDS blastp result: AK243656 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243656 J100088L22 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  20. Arabidopsis CDS blastp result: AK241519 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241519 J065170E12 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  1. Arabidopsis CDS blastp result: AK240655 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240655 J023135E11 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  2. Arabidopsis CDS blastp result: AK242733 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242733 J090047O22 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  3. Arabidopsis CDS blastp result: AK242859 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242859 J090073L24 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  4. Arabidopsis CDS blastp result: AK243187 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243187 J100039E11 At5g62310.1 68418.m07822 incomplete root hair ... elongation (IRE) / protein kin ... putative nearly identical to IRE (incomplete root hair ... elongation) [Arabidopsis thaliana] gi|6729346|dbj| ...

  5. Arabidopsis CDS blastp result: AK242550 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242550 J080319D10 At2g35630.1 68415.m04369 microtubule organization 1 protein (MO...R1) identical to microtubule organization 1 protein GI:14317953 from [Arabidopsis thaliana] 5e-44 ...

  6. Arabidopsis CDS blastp result: AK101368 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK101368 J033035L13 At5g24270.1 calcineurin B-like protein, putative / calcium sensor ... homolog (S ... OS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  7. Arabidopsis CDS blastp result: AK111570 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111570 J013071C24 At5g24270.1 calcineurin B-like protein, putative / calcium sensor ... homolog (S ... OS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  8. Arabidopsis CDS blastp result: AK243065 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243065 J100015N03 At5g24270.1 68418.m02855 calcineurin B-like protein, putative / calcium sensor ... or homolog (SOS3) identical to calcium sensor ... homolog [Arabidopsis thaliana] GI:3309575; similar ...

  9. The fifth international conference on Arabidopsis research

    Energy Technology Data Exchange (ETDEWEB)

    Hangarter, R.; Scholl, R.; Davis, K.; Feldmann, K.

    1993-12-31

    This volume contains abstracts of oral and poster presentations made in conjunction with the Fifth International Conference on Arabidopsis Research held August 19--22, 1993 at the Ohio State University, Columbus, Ohio.

  10. Arabidopsis CDS blastp result: AK070528 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK070528 J023060D13 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... supe ... roxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  11. Arabidopsis CDS blastp result: AK119904 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119904 002-182-A05 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  12. Arabidopsis CDS blastp result: AK104030 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104030 001-020-C01 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  13. Arabidopsis CDS blastp result: AK104160 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104160 006-211-E09 At3g10920.1 superoxide dismutase [Mn], mitochondrial (SODA) / manganese ... sup ... eroxide dismutase (MSD1) identical to manganese ... superoxide dismutase [Arabidopsis thaliana] gi|327 ...

  14. Arabidopsis CDS blastp result: AK287459 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287459 J043019O07 At4g37000.1 68417.m05242 accelerated cell death ... 2 (ACD2) identical to accele ... rated cell death ... 2 (ACD2) GI:12484129 from [Arabidopsis thaliana] 4 ...

  15. Arabidopsis CDS blastp result: AK288034 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288034 J075140H07 At4g37000.1 68417.m05242 accelerated cell death ... 2 (ACD2) identical to accele ... rated cell death ... 2 (ACD2) GI:12484129 from [Arabidopsis thaliana] 5 ...

  16. Arabidopsis CDS blastp result: AK111576 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111576 J013075J23 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  17. Arabidopsis CDS blastp result: AK120838 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK120838 J023022B11 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  18. Arabidopsis CDS blastp result: AK111921 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111921 001-013-A10 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly i...dentical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profil

  19. Arabidopsis CDS blastp result: AK073140 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK073140 J033022I01 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-168 ...

  20. Arabidopsis CDS blastp result: AK120439 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK120439 J013098H20 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-154 ...

  1. Arabidopsis CDS blastp result: AK121378 [KOME

    Lifescience Database Archive (English)

    Full Text Available me 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK121378 J023127F14 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isozy... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-142 ...

  2. Arabidopsis CDS blastp result: AK063856 [KOME

    Lifescience Database Archive (English)

    Full Text Available yme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains a Ser/Thr protein...AK063856 001-122-D05 At2g39840.1 serine/threonine protein phosphatase PP1 isozyme 4 (TOPP4) / phosphoprotein... phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphatase PP1 isoz... phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 6e-46 ...

  3. Terpene Specialized Metabolism in Arabidopsis thaliana

    OpenAIRE

    Tholl, Dorothea; Lee, Sungbeom

    2011-01-01

    Terpenes constitute the largest class of plant secondary (or specialized) metabolites, which are compounds of ecological function in plant defense or the attraction of beneficial organisms. Using biochemical and genetic approaches, nearly all Arabidopsis thaliana (Arabidopsis) enzymes of the core biosynthetic pathways producing the 5-carbon building blocks of terpenes have been characterized and closer insight has been gained into the transcriptional and posttranscriptional/translational mech...

  4. Lipidome signatures in early bovine embryo development.

    Science.gov (United States)

    Sudano, Mateus J; Rascado, Tatiana D S; Tata, Alessandra; Belaz, Katia R A; Santos, Vanessa G; Valente, Roniele S; Mesquita, Fernando S; Ferreira, Christina R; Araújo, João P; Eberlin, Marcos N; Landim-Alvarenga, Fernanda D C

    2016-07-15

    Mammalian preimplantation embryonic development is a complex, conserved, and well-orchestrated process involving dynamic molecular and structural changes. Understanding membrane lipid profile fluctuation during this crucial period is fundamental to address mechanisms governing embryogenesis. Therefore, the aim of the present work was to perform a comprehensive assessment of stage-specific lipid profiles during early bovine embryonic development and associate with the mRNA abundance of lipid metabolism-related genes (ACSL3, ELOVL5, and ELOVL6) and with the amount of cytoplasmic lipid droplets. Immature oocytes were recovered from slaughterhouse-derived ovaries, two-cell embryos, and eight- to 16-cell embryos, morula, and blastocysts that were in vitro produced under different environmental conditions. Lipid droplets content and mRNA transcript levels for ACSL3, ELOVL5, and ELOVL6, monitored by lipid staining and quantitative polymerase chain reaction, respectively, increased at morula followed by a decrease at blastocyst stage. Relative mRNA abundance changes of ACSL3 were closely related to cytoplasmic lipid droplet accumulation. Characteristic dynamic changes of phospholipid profiles were observed during early embryo development and related to unsaturation level, acyl chain length, and class composition. ELOVL5 and ELOVL6 mRNA levels were suggestive of overexpression of membrane phospholipids containing elongated fatty acids with 16, 18, and 20 carbons. In addition, putative biomarkers of key events of embryogenesis, embryo lipid accumulation, and elongation were identified. This study provides a comprehensive description of stage-specific lipidome signatures and proposes a mechanism to explain its potential relationship with the fluctuation of both cytoplasmic lipid droplets content and mRNA levels of lipid metabolism-related genes during early bovine embryo development. PMID:27107972

  5. The pattern of polymorphism in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available We resequenced 876 short fragments in a sample of 96 individuals of Arabidopsis thaliana that included stock center accessions as well as a hierarchical sample from natural populations. Although A. thaliana is a selfing weed, the pattern of polymorphism in general agrees with what is expected for a widely distributed, sexually reproducing species. Linkage disequilibrium decays rapidly, within 50 kb. Variation is shared worldwide, although population structure and isolation by distance are evident. The data fail to fit standard neutral models in several ways. There is a genome-wide excess of rare alleles, at least partially due to selection. There is too much variation between genomic regions in the level of polymorphism. The local level of polymorphism is negatively correlated with gene density and positively correlated with segmental duplications. Because the data do not fit theoretical null distributions, attempts to infer natural selection from polymorphism data will require genome-wide surveys of polymorphism in order to identify anomalous regions. Despite this, our data support the utility of A. thaliana as a model for evolutionary functional genomics.

  6. Molecular Characterization of Arabidopsis GAL4/UAS Enhancer Trap Lines Identifies Novel Cell-Type-Specific Promoters.

    Science.gov (United States)

    Radoeva, Tatyana; Ten Hove, Colette A; Saiga, Shunsuke; Weijers, Dolf

    2016-06-01

    Cell-type-specific gene expression is essential to distinguish between the numerous cell types of multicellular organism. Therefore, cell-type-specific gene expression is tightly regulated and for most genes RNA transcription is the central point of control. Thus, transcriptional reporters are broadly used markers for cell identity. In Arabidopsis (Arabidopsis thaliana), a recognized standard for cell identities is a collection of GAL4/UAS enhancer trap lines. Yet, while greatly used, very few of them have been molecularly characterized. Here, we have selected a set of 21 frequently used GAL4/UAS enhancer trap lines for detailed characterization of expression pattern and genomic insertion position. We studied their embryonic and postembryonic expression domains and grouped them into three groups (early embryo development, late embryo development, and embryonic root apical meristem lines) based on their dominant expression. We show that some of the analyzed lines are expressed in a domain often broader than the one that is reported. Additionally, we present an overview of the location of the T-DNA inserts of all lines, with one exception. Finally, we demonstrate how the obtained information can be used for generating novel cell-type-specific marker lines and for genotyping enhancer trap lines. The knowledge could therefore support the extensive use of these valuable lines. PMID:27208300

  7. Arabidopsis seedling flood-inoculation technique: a rapid and reliable assay for studying plant-bacterial interactions

    Directory of Open Access Journals (Sweden)

    Uppalapati Srinivasa R

    2011-10-01

    Full Text Available Abstract Background The Arabidopsis thaliana-Pseudomonas syringae model pathosystem is one of the most widely used systems to understand the mechanisms of microbial pathogenesis and plant innate immunity. Several inoculation methods have been used to study plant-pathogen interactions in this model system. However, none of the methods reported to date are similar to those occurring in nature and amicable to large-scale mutant screens. Results In this study, we developed a rapid and reliable seedling flood-inoculation method based on young Arabidopsis seedlings grown on MS medium. This method has several advantages over conventional soil-grown plant inoculation assays, including a shorter growth and incubation period, ease of inoculation and handling, uniform infection and disease development, requires less growth chamber space and is suitable for high-throughput screens. In this study we demonstrated the efficacy of the Arabidopsis seedling assay to study 1 the virulence factors of P. syringae pv. tomato DC3000, including type III protein secretion system (TTSS and phytotoxin coronatine (COR; 2 the effector-triggered immunity; and 3 Arabidopsis mutants affected in salicylic acid (SA- and pathogen-associated molecular pattern (PAMPs-mediated pathways. Furthermore, we applied this technique to study nonhost resistance (NHR responses in Arabidopsis using nonhost pathogens, such as P. syringae pv. tabaci, pv. glycinea and pv. tomato T1, and confirmed the functional role of FLAGELLIN-SENSING 2 (FLS2 in NHR. Conclusions The Arabidopsis seedling flood-inoculation assay provides a rapid, efficient and economical method for studying Arabidopsis-Pseudomonas interactions with minimal growth chamber space and time. This assay could also provide an excellent system for investigating the virulence mechanisms of P. syringae. Using this method, we demonstrated that FLS2 plays a critical role in conferring NHR against nonhost pathovars of P. syringae, but not to

  8. Identification of novel auxin responses during Arabidopsis embryogenesis

    NARCIS (Netherlands)

    Rademacher, E.H.

    2009-01-01

    Plants normally form one embryo per seed. Under special circumstances, such as death of the embryo, a second embryo can develop from a supportive structure called the suspensor. These suspensor cells therefore provide a reservoir of stem cells for the generation of secondary embryos. At the start of

  9. Sequential steps for developmental arrest in Arabidopsis seeds

    NARCIS (Netherlands)

    Raz, V.; Bergervoet, J.H.W.; Koornneef, M.

    2001-01-01

    The continuous growth of the plant embryo is interrupted during the seed maturation processes which results in a dormant seed. The embryo continues development after germination when it grows into a seedling. The embryo growth phase starts after morphogenesis and ends when the embryo fills the seed

  10. SOT1, a pentatricopeptide repeat protein with a small MutS-related domain, is required for correct processing of plastid 23S-4.5S rRNA precursors in Arabidopsis thaliana.

    Science.gov (United States)

    Wu, Wenjuan; Liu, Sheng; Ruwe, Hannes; Zhang, Delin; Melonek, Joanna; Zhu, Yajuan; Hu, Xupeng; Gusewski, Sandra; Yin, Ping; Small, Ian D; Howell, Katharine A; Huang, Jirong

    2016-03-01

    Ribosomal RNA processing is essential for plastid ribosome biogenesis, but is still poorly understood in higher plants. Here, we show that SUPPRESSOR OF THYLAKOID FORMATION1 (SOT1), a plastid-localized pentatricopeptide repeat (PPR) protein with a small MutS-related domain, is required for maturation of the 23S-4.5S rRNA dicistron. Loss of SOT1 function leads to slower chloroplast development, suppression of leaf variegation, and abnormal 23S and 4.5S processing. Predictions based on the PPR motif sequences identified the 5' end of the 23S-4.5S rRNA dicistronic precursor as a putative SOT1 binding site. This was confirmed by electrophoretic mobility shift assay, and by loss of the abundant small RNA 'footprint' associated with this site in sot1 mutants. We found that more than half of the 23S-4.5S rRNA dicistrons in sot1 mutants contain eroded and/or unprocessed 5' and 3' ends, and that the endonucleolytic cleavage product normally released from the 5' end of the precursor is absent in a sot1 null mutant. We postulate that SOT1 binding protects the 5' extremity of the 23S-4.5S rRNA dicistron from exonucleolytic attack, and favours formation of the RNA structure that allows endonucleolytic processing of its 5' and 3' ends. PMID:26800847

  11. Separation of ballistic and diffusive fluorescence photons in confocal Light-Sheet Microscopy of Arabidopsis roots

    Science.gov (United States)

    Meinert, Tobias; Tietz, Olaf; Palme, Klaus J.; Rohrbach, Alexander

    2016-01-01

    Image quality in light-sheet fluorescence microscopy is strongly affected by the shape of the illuminating laser beam inside embryos, plants or tissue. While the phase of Gaussian or Bessel beams propagating through thousands of cells can be partly controlled holographically, the propagation of fluorescence light to the detector is difficult to control. With each scatter process a fluorescence photon loses information necessary for the image generation. Using Arabidopsis root tips we demonstrate that ballistic and diffusive fluorescence photons can be separated by analyzing the image spectra in each plane without a priori knowledge. We introduce a theoretical model allowing to extract typical scattering parameters of the biological material. This allows to attenuate image contributions from diffusive photons and to amplify the relevant image contributions from ballistic photons through a depth dependent deconvolution. In consequence, image contrast and resolution are significantly increased and scattering artefacts are minimized especially for Bessel beams with confocal line detection. PMID:27553506

  12. Separation of ballistic and diffusive fluorescence photons in confocal Light-Sheet Microscopy of Arabidopsis roots.

    Science.gov (United States)

    Meinert, Tobias; Tietz, Olaf; Palme, Klaus J; Rohrbach, Alexander

    2016-01-01

    Image quality in light-sheet fluorescence microscopy is strongly affected by the shape of the illuminating laser beam inside embryos, plants or tissue. While the phase of Gaussian or Bessel beams propagating through thousands of cells can be partly controlled holographically, the propagation of fluorescence light to the detector is difficult to control. With each scatter process a fluorescence photon loses information necessary for the image generation. Using Arabidopsis root tips we demonstrate that ballistic and diffusive fluorescence photons can be separated by analyzing the image spectra in each plane without a priori knowledge. We introduce a theoretical model allowing to extract typical scattering parameters of the biological material. This allows to attenuate image contributions from diffusive photons and to amplify the relevant image contributions from ballistic photons through a depth dependent deconvolution. In consequence, image contrast and resolution are significantly increased and scattering artefacts are minimized especially for Bessel beams with confocal line detection. PMID:27553506

  13. Multiple ovulation and embryo transfer (MOET in camels: An overview

    Directory of Open Access Journals (Sweden)

    Binoy S. Vettical

    2016-04-01

    Full Text Available Unlike in other domestic animal species like cattle, reproductive biotechnologies like Artificial Insemination (AI and Embryo Transfer (ET are not well developed and thus are not being used as routine breeding procedures in camels. One of the important objectives of this manuscript is to focus on analyzing the present status of Multiple Ovulation and Embryo Transfer (MOET in camels and its future perspectives. Camels are induced ovulators, thus require hormonal treatment to induce ovulation and control the follicular cycles, which is the main reason why protocols used in other domestic animal species cannot be directly used in this species. The review suggests that the best method for super stimulation of ovaries in camels is use of a combination of Equine Chorionic Gonadotropin (eCG and Follicle Stimulating Hormone (FSH at any stage after elimination of dominant follicle if any or at the early stage of the follicular wave and ovulation of the developed multiple follicles can be achieved by mating donors. The review highlights that a better pregnancy rate is achieved with recipients who ovulate 24 h after the donor.

  14. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Junaid ASLAM

    2014-06-01

    Full Text Available Catharanthus roseus (L. G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in vitro germinated seeds on which somatic embryos, differentiated in numbers, particularly on 2,4-D (1.0 mg/L Murashige and Skoog (MS was medium. To understand more about the regeneration method and in vitro formed embryos SEM was performed. The SEM study revealed normal somatic embryo origin and development from globular to heart-, torpedo- and then into cotyledonary-stage of embryos. At early stage, the embryos were clustered together in a callus mass and could not easily be detached from the parental tissue. The embryos were often long cylindrical structure with or without typical notch at the tip. Secondary embryos were also formed on primary embryo structure. The advanced cotyledonary embryos showed prominent roots and shoot axis, which germinated into plantlets. The morphology, structure and other details of somatic embryos at various stages were presented.

  15. Classification of embryo sacs in the Eragrostis curvula Complex

    Directory of Open Access Journals (Sweden)

    T. B. Vorster

    1984-12-01

    Full Text Available At each of 17 collecting points between Johannesburg and Brits in the Transvaal, three plants which belong to the  Eragrostis curvula Complex were collected and studied. A total o f 3 902 embryo sacs was examined in this sample. Of the embryo sacs examined, 3 306 were apomictic by means of diplospory, whereas 99 were sexual monosporic Polygonum-type embryo sacs. One hundred and nineteen embryo sacs were abnormal or divergent, and 378 were degenerated. There are indications that seasonal climatic fluctuations may be responsible for embryo sacs developing abnormally or degenerating. Simple and multiple correlations confirmed that sexual embryo sacs usually do not develop abnormally or degenerate during the later developmental stages. This finding lends credence to both the system of classification of individual embryo sacs and to the validity of the estimate of the proportion of sexuality of the plants sampled at each sampling point.

  16. A fully automated robotic system for microinjection of zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Wenhui Wang

    Full Text Available As an important embodiment of biomanipulation, injection of foreign materials (e.g., DNA, RNAi, sperm, protein, and drug compounds into individual cells has significant implications in genetics, transgenics, assisted reproduction, and drug discovery. This paper presents a microrobotic system for fully automated zebrafish embryo injection, which overcomes the problems inherent in manual operation, such as human fatigue and large variations in success rates due to poor reproducibility. Based on computer vision and motion control, the microrobotic system performs injection at a speed of 15 zebrafish embryos (chorion unremoved per minute, with a survival rate of 98% (n = 350 embryos, a success rate of 99% (n = 350 embryos, and a phenotypic rate of 98.5% (n = 210 embryos. The sample immobilization technique and microrobotic control method are applicable to other biological injection applications such as the injection of mouse oocytes/embryos and Drosophila embryos to enable high-throughput biological and pharmaceutical research.

  17. EFFECT OF ADMINISTRATION OF ETIZOLAM ON THE DEVELOPMENT OF THE CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Shweta P. Alai et al.

    2012-02-01

    Full Text Available There are various drugs used in daily life. Some of them show hazardous effect on various organs and some of them shows even lethal effect. Such drugs are required to banned. One of them is Etizolam (marketed under the brand name Sedekopan, Pasaden or Depas is a drug which is a thiebenzothiodiazepines analog. The aim of this work is done to compare the effect of administration of the etizolam drug at (Zero-day before incubation and at the (5-day first week of incubation, to get an idea about the extent of the teratogenic effect of this drug on the development of chick embryo. So that morphological and biochemical studies were done on the chick embryo of 8- and 16-days old chick embryos treated with (0.5mg/ml egg of etizolam on the (zero and 5-th days of incubation. Etizolam caused abnormality in concentration dependent manner. Enlarged remains of primitive streak was seen at 0.1mg/ml and o.3mg/ml concentration of Etizolam embryo dies. Etizolam inhibit development of somites of the development of 5-day at of incubation also it does not allow the development of notochord. The toxic effects of the drug was seen also more at 16-days treated chick embryos and the drug induced death of chick embryo at both 8- and 16-days treated with 0.1mg/ml and o.3mg/ml. The conclusion from this study was the etizolam drug has dangerous effects on tissues and with powerful toxicity on the cells, because the drug absorbed rapidly with peak plasma levels achieved between 30 minutes and 2 hours and has a mean elimination half life of about 3 and a half hours.

  18. The developmental toxicity of three carrier solvents using embryos of the grass shrimp, Palaemonetes pugio

    International Nuclear Information System (INIS)

    The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water-soluble fraction of Number 2 fuel oil which indicates this test may be ideal for use as an estuarine developmental toxicity test. Many chemicals that require testing of this nature are insoluble in water. To determine the possible use of carrier solvents in the grass shrimp bioassays, detailed concentration-response curves for each solvent were performed using two test methods. LC50 values for each method were obtained. The first test was a 4-day assay that included the time of hatch, a critical life stage of these embryos. The second test was a 12-d assay which included development from tissue cap stage embryos through 2 days post hatch. The average 4-day LC50s for ETOH, DMSO and acetone were 12.07, 22.57, and 6.80 g/L, respectively. The average 12-day LC50s for ETOH, DMSO and Acetone were 3.63, 12.33 and 6.94 g/L, respectively. The coefficients of variation of each test were always less than 25.2%. Eye malformations were observed with embryos exposed to ETOH, while embryos exposed to DMSO and acetone showed very little embryo malformation. One experiment showed abnormal development of the last abdominal segment. Based on the concentration-response curves, the maximum allowable limit of ETOH, DMSO and acetone to be used as a carrier should be 1, 6, and 4 g/L, respectively

  19. Gene transfer into older chicken embryos by ex ovo electroporation.

    Science.gov (United States)

    Luo, Jiankai; Yan, Xin; Lin, Juntang; Rolfs, Arndt

    2012-01-01

    The chicken embryo provides an excellent model system for studying gene function and regulation during embryonic development. In ovo electroporation is a powerful method to over-express exogenous genes or down-regulate endogenous genes in vivo in chicken embryos(1). Different structures such as DNA plasmids encoding genes(2-4), small interfering RNA (siRNA) plasmids(5), small synthetic RNA oligos(6), and morpholino antisense oligonucleotides(7) can be easily transfected into chicken embryos by electroporation. However, the application of in ovo electroporation is limited to embryos at early incubation stages (younger than stage HH20--according to Hamburg and Hamilton)(8) and there are some disadvantages for its application in embryos at later stages (older than stage HH22--approximately 3.5 days of development). For example, the vitelline membrane at later stages is usually stuck to the shall membrane and opening a window in the shell causes rupture of the vessels, resulting in death of the embryos; older embryos are covered by vitelline and allantoic vessels, where it is difficult to access and manipulate the embryos; older embryos move vigorously and is difficult to control the orientation through a relatively small window in the shell. In this protocol we demonstrate an ex ovo electroporation method for gene transfer into chicken embryos at late stages (older than stage HH22). For ex ovo electroporation, embryos are cultured in Petri dishes(9) and the vitelline and allantoic vessels are widely spread. Under these conditions, the older chicken embryos are easily accessed and manipulated. Therefore, this method overcomes the disadvantages of in ovo electroporation applied to the older chicken embryos. Using this method, plasmids can be easily transfected into different parts of the older chicken embryos(10-12). PMID:22872055

  20. Expression of MADS-box genes during the embryonic phase in Arabidopsis.

    Science.gov (United States)

    Lehti-Shiu, Melissa D; Adamczyk, Benjamin J; Fernandez, Donna E

    2005-05-01

    MADS domain factors play important roles as developmental regulators in plants. In Arabidopsis thaliana, MADS domain proteins have been shown to regulate various processes during the vegetative and reproductive phases. Relatively little is known, however, about family members expressed during the embryonic phase and their function. To determine which MADS-box genes are expressed during the embryonic phase in Arabidopsis, a family-wide survey involving gene-specific primers and RT-PCR was conducted. Transcripts corresponding to 64 (out of 109 total) family members could be detected in RNA samples isolated from embryonic culture tissue. Eight MADS-box genes that appear to be expressed at higher levels during the embryonic phase than in seedlings or in inflorescence apices were identified. The spatial pattern of expression in developing seeds was characterized for four MADS-box genes (FLOWERING LOCUS C, FLOWERING LOCUS M, AGAMOUS-LIKE 15, and AGAMOUS-LIKE 18) using reporter constructs encoding translational fusions to GUS. All four are expressed in cells throughout the endosperm and embryo. Finally, to test the hypothesis that AGAMOUS-LIKE15 (AGL15) and AGAMOUS-LIKE18 (AGL18) play essential roles during the embryonic phase, plants carrying T-DNA insertions that disrupt these genes were isolated. No embryo defects were observed in agl15 or agl18 single mutants or in agl15agl18 double mutants. These results indicate that multiple regulatory pathways that involve MADS domain factors are likely to operate in embryonic tissues, and that genetic and/or functional redundancy are likely to be as prevalent as in other phases of the life cycle. PMID:16028119

  1. Depletion of primordial germ cells (PGCs) by X-irradiation to extraembryonic region of chicken embryos and expression of xenotransplanted quail PGCs

    International Nuclear Information System (INIS)

    The generation of germline chimeras by the transfer of primordial germ cells (PGCs) requires incorporation of the PGCs of the donor into the gonadal tissue of the recipient embryo. We investigated the utility of soft x-irradiation with application of a lead (12 x 3 x 0.25 mm, - 0.1 g) shield to the embryo proper for the production of chicken-quail germline chimeras. Chicken embryos shielded during irradiation for 120s (- 7.2 Gy) at stages 13 to 17 showed a hatchability of 35% (106/301), whereas the hatchability of unshielded embryos was 26% (27/105). The relative population of gonadal PGCs at stage 30 for embryos irradiated at stage 13 with or without shielding was 13 and 5%, respectively, of the value for nonirradiated controls. Chicken embryos irradiated at stages 13 or 14 with or without shielding and transfused with quail embryonic blood containing PGCs each exhibited - 130 relative population of donor PGCs in the left gonad at stage 30. Xenotransplanted hatchlings exhibited donor-derived PGCs as detected by Southern hybridization and PCR. Exposure of chicken embryos to - 7.2 Gy of x-radiation at stage 13 with the application of a lead shield to the embryo proper is thus a feasible approach to depletion of endogenous germ cells and the production of chicken-quail germline chimeras

  2. Microfluidic EmbryoSort technology: towards in flow analysis, sorting and dispensing of individual vertebrate embryos

    Science.gov (United States)

    Fuad, Nurul M.; Wlodkowic, Donald

    2013-12-01

    The demand to reduce the numbers of laboratory animals has facilitated the emergence of surrogate models such as tests performed on zebrafish (Danio rerio) or African clawed frog's (Xenopus levis) eggs, embryos and larvae. Those two model organisms are becoming increasingly popular replacements to current adult animal testing in toxicology, ecotoxicology and also in drug discovery. Zebrafish eggs and embryos are particularly attractive for toxicological analysis due their size (diameter 1.6 mm), optical transparency, large numbers generated per fish and very straightforward husbandry. The current bottleneck in using zebrafish embryos for screening purposes is, however, a tedious manual evaluation to confirm the fertilization status and subsequent dispensing of single developing embryos to multitier plates to perform toxicity analysis. Manual procedures associated with sorting hundreds of embryos are very monotonous and as such prone to significant analytical errors due to operator's fatigue. In this work, we present a proofof- concept design of a continuous flow embryo sorter capable of analyzing, sorting and dispensing objects ranging in size from 1.5 - 2.5 mm. The prototypes were fabricated in polymethyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining. The application of additive manufacturing processes to prototype Lab-on-a-Chip sorters using both fused deposition manufacturing (FDM) and stereolithography (SLA) were also explored. The operation of the device was based on a revolving receptacle capable of receiving, holding and positioning single fish embryos for both interrogation and subsequent sorting. The actuation of the revolving receptacle was performed using a DC motor and/or microservo motor. The system was designed to separate between fertilized (LIVE) and non-fertilized (DEAD) eggs, based on optical transparency using infrared (IR) emitters and receivers.

  3. Advances in Arabidopsis research in China from 2006 to 2007

    Institute of Scientific and Technical Information of China (English)

    LIANG Yan; ZUO JianRu; YANG WeiCai

    2007-01-01

    @@ Arabidopsis thaliana, a model plant species, has a number of advantages over other plant species as an experimental organism due to many of its genetic and genomic features. The Chinese Arabidopsis community has made significant contributions to plant biology research in recent years[1,2]. In 2006, studies of plant biology in China received more attention than ever before, especially those pertaining to Arabidopsis research. Here we briefly summarize recent advances in Arabidopsis research in China.

  4. ZmSOC1, a MADS-Box Transcription Factor from Zea mays, Promotes Flowering in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Suzhou Zhao

    2014-11-01

    Full Text Available Zea mays is an economically important crop, but its molecular mechanism of flowering remains largely uncharacterized. The gene, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1, integrates multiple flowering signals to regulate floral transition in Arabidopsis. In this study, ZmSOC1 was isolated from Zea mays. Sequence alignment and phylogenetic analysis demonstrated that the ZmSOC1 protein contained a highly conserved MADS domain and a typical SOC1 motif. ZmSOC1 protein was localized in the nucleus in protoplasts and showed no transcriptional activation activity in yeast cells. ZmSOC1 was highly expressed in maize reproductive organs, including filaments, ear and endosperm, but expression was very low in embryos; on the other hand, the abiotic stresses could repress ZmSOC1 expression. Overexpression of ZmSOC1 resulted in early flowering in Arabidopsis through increasing the expression of AtLFY and AtAP1. Overall, these results suggest that ZmSOC1 is a flowering promoter in Arabidopsis.

  5. Use of Insulin to Increase Epiblast Cell Number: Towards a New Approach for Improving ESC Isolation from Human Embryos

    Directory of Open Access Journals (Sweden)

    Jared M. Campbell

    2013-01-01

    Full Text Available Human embryos donated for embryonic stem cell (ESC derivation have often been cryopreserved for 5–10 years. As a consequence, many of these embryos have been cultured in media now known to affect embryo viability and the number of ESC progenitor epiblast cells. Historically, these conditions supported only low levels of blastocyst development necessitating their transfer or cryopreservation at the 4–8-cell stage. As such, these embryos are donated at the cleavage stage and require further culture to the blastocyst stage before hESC derivation can be attempted. These are generally of poor quality, and, consequently, the efficiency of hESC derivation is low. Recent work using a mouse model has shown that the culture of embryos from the cleavage stage with insulin to day 6 increases the blastocyst epiblast cell number, which in turn increases the number of pluripotent cells in outgrowths following plating, and results in an increased capacity to give rise to ESCs. These findings suggest that culture with insulin may provide a strategy to improve the efficiency with which hESCs are derived from embryos donated at the cleavage stage.

  6. Post-Transcriptional Control of Gene Expression in Mouse Early Embryo Development: A View from the Tip of the Iceberg

    Directory of Open Access Journals (Sweden)

    Claudio Sette

    2011-04-01

    Full Text Available Fertilization is a very complex biological process that requires the perfect cooperation between two highly specialized cells: the male and female gametes. The oocyte provides the physical space where this process takes place, most of the energetic need, and half of the genetic contribution. The spermatozoon mostly contributes the other half of the chromosomes and it is specialized to reach and to penetrate the oocyte. Notably, the mouse oocyte and early embryo are transcriptionally inactive. Hence, they fully depend on the maternal mRNAs and proteins stored during oocyte maturation to drive the onset of development. The new embryo develops autonomously around the four-cell stage, when maternal supplies are exhausted and the zygotic genome is activated in mice. This oocyte-to-embryo transition needs an efficient and tightly regulated translation of the maternally-inherited mRNAs, which likely contributes to embryonic genome activation. Full understanding of post-transcriptional regulation of gene expression in early embryos is crucial to understand the reprogramming of the embryonic genome, it might help driving reprogramming of stem cells in vitro and will likely improve in vitro culturing of mammalian embryos for assisted reproduction. Nevertheless, the knowledge of the mechanism(s underlying this fundamental step in embryogenesis is still scarce, especially if compared to other model organisms. We will review here the current knowledge on the post-transcriptional control of gene expression in mouse early embryos and discuss some of the unanswered questions concerning this fascinating field of biology.

  7. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice.

    Science.gov (United States)

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-07-01

    Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings. PMID:25941326

  8. Neurogenesis in zebrafish - from embryo to adult

    OpenAIRE

    Schmidt, R.; Strähle, U.; Scholpp, S.

    2014-01-01

    Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and ...

  9. Communication compartments in the gastrulating mouse embryo

    OpenAIRE

    1988-01-01

    We characterized the pattern of gap junctional communication in the 7.5- d mouse embryo (at the primitive streak or gastrulation stage). First we examined the pattern of dye coupling by injecting the fluorescent tracers, Lucifer Yellow or carboxyfluorescein, and monitoring the extent of dye spread. These studies revealed that cells within all three germ layers are well coupled, as the injected dye usually spread rapidly from the site of impalement into the neighboring cells. The dye spread, h...

  10. Oxygen control of ethylene biosynthesis during seed development in Arabidopsis thaliana (L.) Heynh

    Science.gov (United States)

    Ramonell, K. M.; McClure, G.; Musgrave, M. E.

    2002-01-01

    An unforeseen side-effect on plant growth in reduced oxygen is the loss of seed production at concentrations around 25% atmospheric (50 mmol mol-1 O2). In this study, the model plant Arabidopsis thaliana (L.) Heynh. cv. 'Columbia' was used to investigate the effect of low oxygen on ethylene biosynthesis during seed development. Plants were grown in a range of oxygen concentrations (210 [equal to ambient], 160, 100, 50 and 25 mmol mol-1) with 0.35 mmol mol-1 CO2 in N2. Ethylene in full-sized siliques was sampled using gas chromatography, and viable seed production was determined at maturity. Molecular analysis of ethylene biosynthesis was accomplished using cDNAs encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase in ribonuclease protection assays and in situ hybridizations. No ethylene was detected in siliques from plants grown at 50 and 25 mmol mol-1 O2. At the same time, silique ACC oxidase mRNA increased three-fold comparing plants grown under the lowest oxygen with ambient controls, whereas ACC synthase mRNA was unaffected. As O2 decreased, tissue-specific patterning of ACC oxidase and ACC synthase gene expression shifted from the embryo to the silique wall. These data demonstrate how low O2 modulates the activity and expression of the ethylene biosynthetic pathway during seed development in Arabidopsis.

  11. In vitro embryo culture of rarely endangered musella lasiocarpa (musaceae) with embryo dormancy

    International Nuclear Information System (INIS)

    Musella lasiocarpa (Musaceae) is an ornamental annually producing many viable seeds, but seldom recruited by seeds in the wild. One mature Musella seed has a small mushroom-shaped embryo without discernible organ differentiation. Therefore, freshly-harvested mature seeds are dormant. When the seeds gradually finished differentiation during warm stratification at 23 degree C, they germinated to 82%. Besides, extracted embryos from fresh seeds did not germinate on the basal medium of Murshige and Skoog medium (MS) supplemented with 3% sucrose and 0.8% agar, but they were induced to form calli and root by media. The optimum medium for inducing calli was MS + 1.0 mg/L 6-BA + 0.05 mg/L NAA + 100 mg/L Vc with the highest proliferation coefficient (7.3) in 35 days. Moreover, the embryos from the 6-month warm stratified seeds could proliferate on the suitable medium. The optimal medium for rooting was MS + 0.5 mg/L 2, 4-D + Vitamin C 100 mg/L. The results confirmed that both the embryo developmental stage and appropriate combination of chemicals significantly affected seed germination and In vitro embryo culture of this species. (author)

  12. From Stress to Embryos: Some of the Problems for Induction and Maturation of Somatic Embryos.

    Science.gov (United States)

    Ochatt, Sergio J; Revilla, Maria Angeles

    2016-01-01

    Although somatic embryogenesis has been successfully achieved in numerous plant species, little is known about the mechanism(s) underlying this process. Changes in the balance of growth regulators of the culture medium, osmolarity, or amino acids as well as the genotype and developmental stage of the tissue used as initial explant may have a pivotal influence on the induction of somatic embryogenic cultures. Moreover, different stress agents (ethylene, activated charcoal, cold or heat or electrical shocks), as well as abscisic acid, can also foster the induction or further development of somatic embryos. In the process, cells first return to a stem cell-like status and then either enter their new program or dye when the stress level exceeds cell tolerance. Recalcitrance to differentiation of somatic cells into embryos is frequently observed, and problems such as secondary or recurrent embryogenesis, embryo growth arrest (at the globular stage or during the transition from torpedo to cotyledonary stage), and development of only the aerial part of somatic embryos can appear, interfering with normal germination and conversion of embryos to plants. Some solutions to solve these problems associated to embryogenesis are proposed and two very efficient somatic embryogenesis protocols for two model plant species are detailed. PMID:26619886

  13. Characterization of embryo-specific genes

    Energy Technology Data Exchange (ETDEWEB)

    Sung, R.

    1992-06-12

    The objective of the proposed research is to characterize the function and regulation of a set of embryonic genes which are expressed in the embryos, not in the plants. 22 cDNA clones were isolated from a cDNA library we constructed using mRNAS of -carrot somatic embryos. These cDNA clones identified mRNA species that are present in the somatic and zygotic embryos, but not in adult plants. The sequence of all 22cDNA clones were determined; genomic clones for three cDNA clones, DC8, DC59, and DC49 were isolated and gene sequences determined. DC8, DC49, and several other genes identified by the cDNA sequences belong to the category of late embryogenesis abundant protein genes, Lea. The function of these gens have not yet been determined, but they share common structural features, are regulated by ABA and are speculated to play a role in seed desiccation.

  14. Embryos, DOHaD and David Barker.

    Science.gov (United States)

    Fleming, T P; Velazquez, M A; Eckert, J J

    2015-10-01

    The early embryo and periconceptional period is a window during which environmental factors may cause permanent change in the pattern and characteristics of development leading to risk of adult onset disease. This has now been demonstrated across small and large animal models and also in the human. Most evidence of periconceptional 'programming' has emerged from maternal nutritional models but also other in vivo and in vitro conditions including assisted reproductive treatments, show consistent outcomes. This short review first reports on the range of environmental in vivo and in vitro periconceptional models and resulting long-term outcomes. Second, it uses the rodent maternal low protein diet model restricted to the preimplantation period and considers the stepwise maternal-embryonic dialogue that comprises the induction of programming. This dialogue leads to cellular and epigenetic responses by the embryo, mainly identified in the extra-embryonic cell lineages, and underpins an apparently permanent change in the growth trajectory during pregnancy and associates with increased cardiometabolic and behavioural disease in adulthood. We recognize the important advice of David Barker some years ago to investigate the sensitivity of the early embryo to developmental programming, an insight for which we are grateful. PMID:25952250

  15. Mutations in a plastid-localized elongation factor G alter early stages of plastid development in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Hangarter Roger P

    2007-07-01

    Full Text Available Abstract Background Proper development of plastids in embryo and seedling tissues is critical for plant development. During germination, plastids develop to perform many critical functions that are necessary to establish the seedling for further growth. A growing body of work has demonstrated that components of the plastid transcription and translation machinery must be present and functional to establish the organelle upon germination. Results We have identified Arabidopsis thaliana mutants in a gene that encodes a plastid-targeted elongation factor G (SCO1 that is essential for plastid development during embryogenesis since two T-DNA insertion mutations in the coding sequence (sco1-2 and sco1-3 result in an embryo-lethal phenotype. In addition, a point mutation allele (sco1-1 and an allele with a T-DNA insertion in the promoter (sco1-4 of SCO1 display conditional seedling-lethal phenotypes. Seedlings of these alleles exhibit cotyledon and hypocotyl albinism due to improper chloroplast development, and normally die shortly after germination. However, when germinated on media supplemented with sucrose, the mutant plants can produce photosynthetically-active green leaves from the apical meristem. Conclusion The developmental stage-specific phenotype of the conditional-lethal sco1 alleles reveals differences in chloroplast formation during seedling germination compared to chloroplast differentiation in cells derived from the shoot apical meristem. Our identification of embryo-lethal mutant alleles in the Arabidopsis elongation factor G indicates that SCO1 is essential for plant growth, consistent with its predicted role in chloroplast protein translation.

  16. An Arabidopsis mutant impaired in coenzyme A biosynthesis is sugar dependent for seedling establishment.

    Science.gov (United States)

    Rubio, Silvia; Larson, Tony R; Gonzalez-Guzman, Miguel; Alejandro, Santiago; Graham, Ian A; Serrano, Ramón; Rodriguez, Pedro L

    2006-03-01

    Once the plant coenzyme A (CoA) biosynthetic pathway has been elucidated by comparative genomics, it is feasible to analyze the physiological relevance of CoA biosynthesis in plant life. To this end, we have identified and characterized Arabidopsis (Arabidopsis thaliana) T-DNA knockout mutants of two CoA biosynthetic genes, HAL3A and HAL3B. The HAL3A gene encodes a 4'-phosphopantothenoyl-cysteine decarboxilase that generates 4'-phosphopantetheine. A second gene, HAL3B, whose gene product is 86% identical to that of HAL3A, is present in the Arabidopsis genome. HAL3A appears to have a predominant role over HAL3B according to their respective mRNA expression levels. The hal3a-1, hal3a-2, and hal3b mutants were viable and showed a similar growth rate as that in wild-type plants; in contrast, a hal3a-1 hal3b double mutant was embryo lethal. Unexpectedly, seedlings that were null for HAL3A and heterozygous for HAL3B (aaBb genotype) displayed a sucrose (Suc)-dependent phenotype for seedling establishment, which is in common with mutants defective in beta-oxidation. This phenotype was genetically complemented in aaBB siblings of the progeny and chemically complemented by pantethine. In contrast, seedling establishment of Aabb plants was not Suc dependent, proving a predominant role of HAL3A over HAL3B at this stage. Total fatty acid and acyl-CoA measurements of 5-d-old aaBb seedlings in medium lacking Suc revealed stalled storage lipid catabolism and impaired CoA biosynthesis; in particular, acetyl-CoA levels were reduced by approximately 80%. Taken together, these results provide in vivo evidence for the function of HAL3A and HAL3B, and they point out the critical role of CoA biosynthesis during early postgerminative growth. PMID:16415216

  17. Analysis of Gene Expression Patterns during Seed Coat Development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Gillian Dean; George Haughn; YoncgGuo Cao; DaoQuan Xiang; Nicholas J. Provart; Larissa Ramsay; Abdul Ahada; Rick White; Gopalan Selvaraj; Raju Datla

    2011-01-01

    The seed coat is important for embryo protection,seed hydration,and dispersal.Seed coat composition is also of interest to the agricultural sector,since it impacts the nutritional value for humans and livestock alike.Although some seed coat genes have been identified,the developmental pathways controlling seed coat development are not completely elucidated,and a global genetic program associated with seed coat development has not been reported.This study uses a combination of genetic and genomic approaches in Arabidopsis thaliana to begin to address these knowledge gaps.Seed coat development is a complex process whereby the integuments of the ovule differentiate into specialized cell types.In Arabidopsis,the outermost layer of cells secretes mucilage into the apoplast and develops a secondary cell wall known as a columella.The layer beneath the epidermis,the palisade,synthesizes a secondary cell wall on its inner tangential side.The innermost layer (the pigmented layer or endothelium) produces proanthocyanidins that condense into tannins and oxidize,giving a brown color to mature seeds.Genetic separation of these cell layers was achieved using the ap2-7 and tt16-1 mutants,where the epidermis/palisade and the endothelium do not develop respectively.This genetic ablation was exploited to examine the developmental programs of these cell types by isolating and collecting seed coats at key transitions during development and performing global gene expression analysis.The data indicate that the developmental programs of the epidermis and the pigmented layer proceed relatively independently.Global expression datasets that can be used for identification of new gene candidates for seed coat development were generated.These dataset provide a comprehensive expression profile for developing seed coats in Arabidopsis,and should provide a useful resource and reference for other seed systems.

  18. Classification of plant somatic embryos by computer vision.

    Science.gov (United States)

    Hämäläinen, J J; Kurtén, U; Kauppinen, V

    1993-01-01

    This article deals with the automation of the process of somatic embryogenesis for the propagation of plants. An important problem is the monitoring of the embryo production process in order to decide the time to start harvesting embryos for further processing. The classification algorithm development for somatic embryos of birch (Betula pendula Roth) showed that automated recognition of embryos at different developmental stages is possible. No globular stage embryos were classified to be heart or torpedo stage and no heart or torpedo stage embryos were classified to be at globular stage. Heart and torpedo stage embryos were classified into three developmental classes by a new index that describes the relation of embryo breadth to the length of the root. The probability of classifying a nonembryo as an embryo was less than 1%, and 14% of the object classified as embryos by a human expert were discarded by the algorithm. A computer vision system suitable for automated monitoring of samples from the bioreactor was constructed. PMID:18601243

  19. Blastocyst development potential of D3 low quality embryos

    Institute of Scientific and Technical Information of China (English)

    Zhen Jing-ran; Sun Zhen-yi; Yu Qi; Deng Cheng-yan; Zhou Yuan-zheng; He Fang-fang

    2011-01-01

    Objective:To investigate the potential of blastocyst development of D3 low quality embryos for blastocyst culturing and freezing.Methods:Two thousand one hundred and eighty embryos of 398 IVF/ICSI patients' were observed after D3 embryo transfer.The low-quality embryos were cultured by sequential micro-drops and continuously observed blastocyst formation from D3 to D6.Results:(1) A total of 1,546 low-quality embryos were collected,and 426 blastocysts formed in DS-D6.Total blastocyst formation rate (BFR) was 27.56%,of which embryos with grade 6 Ⅲ/Ⅳ were 40.87 % (318/778),5 Ⅰ /Ⅱ 28.85% (30/104),4Ⅰ/Ⅱ 8.88% (16/180),4Ⅲ/IV 19.72% (56/284),2-3 Ⅰ/Ⅱ 3% (6/200).(2) Embryos with more blastomeres had a higher blastocyst formation rate.The lower qualities of embryos resulted in lower blastocyst formation rate.Conclusions:Low-quality embryos still have the potential to develop into blastocysts.Therefore,they should not be discarded on D3.They should be continually cultured to D6 in order to reduce embryo wastage and get good clinical results.

  20. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    Science.gov (United States)

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2016-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p quality and the cleavage stage of the embryo produced. PMID:26858565

  1. Mining the active proteome of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Renier A. L. Van Der Hoorn

    2011-11-01

    Full Text Available Assigning functions to the >30.000 proteins encoded by the Arabidopsis genome is a challenging task of the Arabidopsis Functional Genomics Network. Although genome-wide technologies like proteomics and transcriptomics have generated a wealth of information that significantly accelerated gene annotation, protein activities are poorly predicted by transcript or protein levels as protein activities are post-translationally regulated. To directly display protein activities in Arabidopsis proteomes, we developed and applied Activity-based Protein Profiling (ABPP. ABPP is based on the use of small molecule probes that react with the catalytic residues of distinct protein classes in an activity-dependent manner. Labeled proteins are separated and detected from proteins gels and purified and identified by mass spectrometry. Using probes of six different chemotypes we have displayed of activities of 76 Arabidopsis proteins. These proteins represent over ten different protein classes that contain over 250 Arabidopsis proteins, including cysteine- serine- and metallo-proteases, lipases, acyltransferases, and the proteasome. We have developed methods for identification of in vivo labeled proteins using click-chemistry and for in vivo imaging with fluorescent probes. In vivo labeling has revealed novel protein activities and unexpected subcellular activities of the proteasome. Labeling of extracts displayed several differential activities e.g. of the proteasome during immune response and methylesterases during infection. These studies illustrate the power of ABPP to display the functional proteome and testify to a successful interdisciplinary collaboration involving chemical biology, organic chemistry and proteomics.

  2. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana

    International Nuclear Information System (INIS)

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3–67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. -- Highlights: ► Iron nanoparticles were synthesized and assessed for bioavailability to Arabidopsis. ► Arabidopsis grew better in the presence of EDTA-bound iron than nanoparticulate iron. ► Arabidopsis grew the same in the presence of nanoparticulate iron compared to no iron. -- Synthesized iron nanoparticles were not bioavailable to Arabidopsis thaliana in agar nutrient media

  3. Dynamics of early embryo development in reference to endosperm and embryo types in angiosperms

    Directory of Open Access Journals (Sweden)

    Olga Erdelska

    2014-02-01

    Full Text Available The mitotic cycle of the endosperm cells is relatively short in the firsit phases of the postfertilization development. The endosperm type does not significantly influence the duration of the mitotic cycle; it might, however, influence the dynamics of zygote and embryo development. The quick development and early end of cellular endosperm proliferation is connected with the fact that it is, in most cases, bound to small, "spare" or "saving" tenuinucellate and unitegmic ovules. Structural differences in the behaviour of the endosperm of different types, in the phase of globular and early heart embryo, might point to differences in the time or way of transition of the embryo from suspensorial to surface nutrition.

  4. Recent Progress in Arabidopsis Research in China: A Preface

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Xu

    2006-01-01

    @@ In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.

  5. Evaluation of 14 organic solvents and carriers for screening applications in zebrafish embryos and larvae.

    Science.gov (United States)

    Maes, Jan; Verlooy, Lien; Buenafe, Olivia E; de Witte, Peter A M; Esguerra, Camila V; Crawford, Alexander D

    2012-01-01

    Zebrafish are rapidly growing in popularity as an in vivo model system for chemical genetics, drug discovery, and toxicology, and more recently also for natural product discovery. Experiments involving the pharmacological evaluation of small molecules or natural product extracts in zebrafish bioassays require the effective delivery of these compounds to embryos and larvae. While most samples to be screened are first solubilized in dimethyl sulfoxide (DMSO), which is then diluted in the embryo medium, often this method is not sufficient to prevent the immediate or eventual precipitation of the sample. Certain compounds and extracts are also not highly soluble in DMSO. In such instances the use of carriers and/or other solvents might offer an alternative means to achieve the required sample concentration. Towards this end, we determined the maximum tolerated concentration (MTC) of several commonly used solvents and carriers in zebrafish embryos and larvae at various developmental stages. Solvents evaluated for this study included acetone, acetonitrile, butanone, dimethyl formamide, DMSO, ethanol, glycerol, isopropanol, methanol, polyethylene glycol (PEG-400), propylene glycol, and solketal, and carriers included albumin (BSA) and cyclodextrin (2-hydroxypropyl-beta-cyclodextrin, or HPBCD). This study resulted in the identification of polyethylene glycol (PEG400), propylene glycol, and methanol as solvents that were relatively well-tolerated over a range of developmental stages. In addition, our results showed that acetone was well-tolerated by embryos but not by larvae, and 1% cyclodextrin (HPBCD) was well-tolerated by both embryos and larvae, indicating the utility of this carrier for compound screening in zebrafish. However, given the relatively small differences (2-3 fold) between concentrations that are apparently safe and those that are clearly toxic, further studies - e.g. omics analyses -should be carried out to determine which cellular processes and signalling

  6. Reciprocal chromosome translocation associated with TDNA-insertion mutation in Arabidopsis: genetic and cytological analyses of consequences for gametophyte development and for construction of doubly mutant lines

    OpenAIRE

    Curtis, Marc J.; Belcram, Katia; Stephanie R Bollmann; Tominey, Colin M.; Hoffman, Peter D.; Mercier, Raphael; Hays, John B.

    2008-01-01

    Chromosomal rearrangements may complicate construction of Arabidopsis with multiple TDNA-insertion mutations. Here, crossing two lines homozygous for insertions in AtREV3 and AtPOLH (chromosomes I and V, respectively) and selfing F1 plants yielded non-Mendelian F2 genotype distributions: frequencies of +/++/+ and 1/1 2/2 progeny were only 0.42 and 0.25%. However, the normal development and fertility of double mutants showed AtPOLH-1 and AtREV3-2 gametes and 1/1 2/2 embryos to be fully viable....

  7. The arabidopsis cyclic nucleotide interactome

    KAUST Repository

    Donaldson, Lara

    2016-05-11

    Background Cyclic nucleotides have been shown to play important signaling roles in many physiological processes in plants including photosynthesis and defence. Despite this, little is known about cyclic nucleotide-dependent signaling mechanisms in plants since the downstream target proteins remain unknown. This is largely due to the fact that bioinformatics searches fail to identify plant homologs of protein kinases and phosphodiesterases that are the main targets of cyclic nucleotides in animals. Methods An affinity purification technique was used to identify cyclic nucleotide binding proteins in Arabidopsis thaliana. The identified proteins were subjected to a computational analysis that included a sequence, transcriptional co-expression and functional annotation analysis in order to assess their potential role in plant cyclic nucleotide signaling. Results A total of twelve cyclic nucleotide binding proteins were identified experimentally including key enzymes in the Calvin cycle and photorespiration pathway. Importantly, eight of the twelve proteins were shown to contain putative cyclic nucleotide binding domains. Moreover, the identified proteins are post-translationally modified by nitric oxide, transcriptionally co-expressed and annotated to function in hydrogen peroxide signaling and the defence response. The activity of one of these proteins, GLYGOLATE OXIDASE 1, a photorespiratory enzyme that produces hydrogen peroxide in response to Pseudomonas, was shown to be repressed by a combination of cGMP and nitric oxide treatment. Conclusions We propose that the identified proteins function together as points of cross-talk between cyclic nucleotide, nitric oxide and reactive oxygen species signaling during the defence response.

  8. Molecular Mechanisms Controlling the Early Mouse Embryo Development

    Directory of Open Access Journals (Sweden)

    Alexandra Ivan

    2010-05-01

    Full Text Available Few are known about the molecular mechanism controlling the early embryo development. The reduce dimension of the embryos, only a few μm, the small quantities of proteins synthesized and the artificial environment influence makes difficult to decode the mechanisms controlling early embryonic stages of development. Although, in the last few years many genes have been showed to be active in the early embryonic stages of development, only a few have been characterized and found to be implicated in the molecular mechanism responsible of preimplantational embryos development. Ped gene (Preimplantational embryo development is considered to be involved in regulation of embryonic cleavage division and subsequent embryo survival. This review presents, based on a rich documentation, the main mechanisms involved in early embryo development.

  9. Chlorophyll content and culture of flax embryos in vitro

    Directory of Open Access Journals (Sweden)

    A. Petrova

    2014-02-01

    Full Text Available During in vitro cultivation of green flax embryos excised 14 days after fertilization on White's medium the chloraphylls a and b are gradually destroyed and the lamellar system of plastids is disintegrated. It was possible, to prolong somewhat the presence of chlorophyll and to enhance embryo growth by culture in the dark and by adding kinetin. Light has a stimulating effect on the germination of embryos. Streptomycin inhibits chlorophyll synthesis not earlier than at germination. Young, green embryos are unable to sumvive and develop on media without sucrose. It is supposed that photosynthesis does not occur in flax embryos in vitro, and that green embryos are not more autotrophic in vitro than those of leucoembryophytes.

  10. Serial Nuclear Transfer of Goat-Rabbit Interspecies Reconstructed Embryos

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-guo; CHENG Li-zi; ZHANG Xiao-rong; LIU Ya; JING Ren-tao; WANG Cun-li; ZHAO Huan; LI Bin; CAO Chen-chong; LI Dong-wei

    2005-01-01

    The experiments of serial nuclear transfer were conducted between Boer goat and rabbit. The enucleated oocytes of rabbit were used as recipients while the blastomeres of goat morula was used as nuclear donor. The reconstructed embryos developing to morula were used as donor for serial cloning. As a result, two generations of reconstructed embryos were obtained, including 58 first generation reconstructed embryos and 14 second generation reconstructed embryos. The fusion rates were 79.5 and 70%, respectively. and there was no significant difference between them (P>0.05). The cleavage rates were 75.9 and 28.6% respectively with significant difference (P<0.01). No blastocyst was obtained from the second generation reconstructed embryos while 13.8% of first generation reconstructed embryos developed to blastocyst.

  11. In vitroembryo outgrowth is a bioassay ofin vivo embryo implantation and development

    Institute of Scientific and Technical Information of China (English)

    Natalie K. Binder; Natalie J. Hannan; David K. Gardner

    2015-01-01

    Objective:To determine the efficacy of embryo outgrowth on fibronectin as a low cost, high throughput alternative to embryo transfer to model embryo attachment and the initial stages of implantation.Methods:Following in vitro embryo culture, embryo quality was assessedviaembryo transfer or embryo outgrowth with metabolic assessment.Results:This study shows that blastocysts attach to fibronectin at the same rate that they implantin vivo, and that the carbohydrate utilisation of embryos that successfully outgrow is comparable to those that are able to develop into a fetus.Conclusions:Embryo outgrowth is a suitable alternative endpoint to embryo transfer.

  12. Effects of multimodal analgesia on the success of mouse embryo transfer surgery.

    Science.gov (United States)

    Parker, John M; Austin, Jamie; Wilkerson, James; Carbone, Larry

    2011-07-01

    Multimodal analgesia is promoted as the best practice pain management for invasive animal research procedures. Universal acceptance and incorporation of multimodal analgesia requires assessing potential effects on study outcome. The focus of this study was to assess effects on embryo survival after multimodal analgesia comprising an opioid and nonsteroidal antiinflammatory drug (NSAID) compared with opioid-only analgesia during embryo transfer procedures in transgenic mouse production. Mice were assigned to receive either carprofen (5 mg/kg) with buprenorphine (0.1 mg/kg; CB) or vehicle with buprenorphine (0.1 mg/kg; VB) in a prospective, double-blinded placebo controlled clinical trial. Data were analyzed in surgical sets of 1 to 3 female mice receiving embryos chimeric for a shared targeted embryonic stem-cell clone and host blastocyst cells. A total of 99 surgical sets were analyzed, comprising 199 Crl:CD1 female mice and their 996 offspring. Neither yield (pups weaned per embryo implanted in the surgical set) nor birth rate (average number of pups weaned per dam in the set) differed significantly between the CB and VB conditions. Multimodal opioid-NSAID analgesia appears to have no significant positive or negative effect on the success of producing novel lines of transgenic mice by blastocyst transfer. PMID:21838973

  13. Hypoxia impairs primordial germ cell migration in zebrafish (Danio rerio embryos.

    Directory of Open Access Journals (Sweden)

    Kwok Hong Lo

    Full Text Available BACKGROUND: As a global environmental concern, hypoxia is known to be associated with many biological and physiological impairments in aquatic ecosystems. Previous studies have mainly focused on the effect of hypoxia in adult animals. However, the effect of hypoxia and the underlying mechanism of how hypoxia affects embryonic development of aquatic animals remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: In the current study, the effect of hypoxia on primordial germ cell (PGC migration in zebrafish embryos was investigated. Hypoxic embryos showed PGC migration defect as indicated by the presence of mis-migrated ectopic PGCs. Insulin-like growth factor (IGF signaling is required for embryonic germ line development. Using real-time PCR, we found that the mRNA expression levels of insulin-like growth factor binding protein (IGFBP-1, an inhibitor of IGF bioactivity, were significantly increased in hypoxic embryos. Morpholino knockdown of IGFBP-1 rescued the PGC migration defect phenotype in hypoxic embryos, suggesting the role of IGFBP-1 in inducing PGC mis-migration. CONCLUSIONS/SIGNIFICANCE: This study provides novel evidence that hypoxia disrupts PGC migration during embryonic development in fish. IGF signaling is shown to be one of the possible mechanisms for the causal link between hypoxia and PGC migration. We propose that hypoxia causes PGC migration defect by inhibiting IGF signaling through the induction of IGFBP-1.

  14. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  15. Arabidopsis thaliana DNA gyrase is targeted to chloroplasts and mitochondria

    Science.gov (United States)

    Wall, Melisa K.; Mitchenall, Lesley A.; Maxwell, Anthony

    2004-01-01

    DNA gyrase is the bacterial DNA topoisomerase (topo) that supercoils DNA by using the free energy of ATP hydrolysis. The enzyme, an A2B2 tetramer encoded by the gyrA and gyrB genes, catalyses topological changes in DNA during replication and transcription, and is the only topo that is able to introduce negative supercoils. Gyrase is essential in bacteria and apparently absent from eukaryotes and is, consequently, an important target for antibacterial agents (e.g., quinolones and coumarins). We have identified four putative gyrase genes in the model plant Arabidopsis thaliana; one gyrA and three gyrB homologues. DNA gyrase protein A (GyrA) has a dual translational initiation site targeting the mature protein to both chloroplasts and mitochondria, and there are individual targeting sequences for two of the DNA gyrase protein B (GyrB) homologues. N-terminal fusions of the organellar targeting sequences to GFPs support the hypothesis that one enzyme is targeted to the chloroplast and another to the mitochondrion, which correlates with supercoiling activity in isolated organelles. Treatment of seedlings and cultured cells with gyrase-specific drugs leads to growth inhibition. Knockout of A. thaliana gyrA is embryo-lethal whereas knockouts in the gyrB genes lead to seedling-lethal phenotypes or severely stunted growth and development. The A. thaliana genes have been cloned in Escherichia coli and found to complement gyrase temperature-sensitive strains. This report confirms the existence of DNA gyrase in eukaryotes and has important implications for drug targeting, organelle replication, and the evolution of topos in plants. PMID:15136745

  16. Cryoprotectants protect medaka (Oryzias latipes) embryos from chilling injury.

    Science.gov (United States)

    Zhang, Qing-Jing; Zhou, Guang-Bin; Wang, Yan-Ping; Fu, Xiang-Wei; Zhu, Shi-En

    2012-01-01

    This study was conducted to investigate the effect of six cryoprotectants (dimethyl sulfoxide (DMSO), glycerol (Gly), methanol (MeOH), ethylene glycol (EG), 1,2-propylene glycol (PG) and N,N-dimethylformamide (DMF) on the survival of medaka (Oryzias lapites) embryos at low temperatures (0 and -5C). Firstly, the embryos at 8 to 16-cell stages were exposed to different concentrations (1 to 4 mol per L) of DMSO, Gly, MeOH, EG, PG and DMF for 40min at 26C. After removal of the cryoprotectants (CPAs), the embryo survivals were assessed by their development into live fries following 9 day of culture. The results showed that the higher concentration of the CPA, the lower survival of the embryos; and that the toxicity of the six CPAs to medaka embryos is in the order of PG < MeOH = DMSO < Gly < EG < DMF (P < 0.05). Secondly, based on the results obtained above, embryos at 8 to 16-cell stages or other stages were exposed to 2 mol per L of PG, MeOH or DMSO for up to 180 min at 0C and up to 80 min at -5C respectively. The 8 to 16-cell embryos treated with MeOH at low temperatures showed highest survival. Thirdly, when embryos at different stages were treated with 2 mol per L of MeOH at -5C for 60 min, 16-somite stage embryos showed highest survival, followed by 4-somite, neurula, 50 percent epiboly, blastula, 32-cell and 8 to 16-cell embryos. These results demonstrated that PG had the lowest toxicity to medaka embryos among the six permeable CPAs at 26C, whereas MeOH showed highest cryoprotective efficiency under chilling conditions and chilling injury decreased gradually with the development of medaka embryos. PMID:22576114

  17. Toxicity and teratogenesis in zebrafish embryos (Danio rerio)

    OpenAIRE

    Strecker, Ruben

    2013-01-01

    The present thesis gives an overview about the potentials zebrafish embryos can be used for in the area of ecotoxicology. The first chapter summarizes the outcome of the ZFET (Zebrafish Embryo Toxicity Test) OECD validation study, an international attempt for the standardization and development of an embryo toxicity test as an (animal) alternative test to the acute (adult) fish test which is a mandatory component of chemical registration worldwide. The overall reproducibility of the ZFET w...

  18. Heartbeat, embryo communication and hatching synchrony in snake eggs

    OpenAIRE

    Fabien Aubret; Gaëlle Blanvillain; Florent Bignon; Kok, Philippe J. R.

    2016-01-01

    Communication is central to life at all levels of complexity, from cells to organs, through to organisms and communities. Turtle eggs were recently shown to communicate with each other in order to synchronise their development and generate beneficial hatching synchrony. Yet the mechanism underlying embryo to embryo communication remains unknown. Here we show that within a clutch, developing snake embryos use heart beats emanating from neighbouring eggs as a clue for their metabolic level, in ...

  19. Gene Transfer into Older Chicken Embryos by ex ovo Electroporation

    OpenAIRE

    Luo, Jiankai; Yan, Xin; Lin, Juntang; Rolfs, Arndt

    2012-01-01

    The chicken embryo provides an excellent model system for studying gene function and regulation during embryonic development. In ovo electroporation is a powerful method to over-express exogenous genes or down-regulate endogenous genes in vivo in chicken embryos1. Different structures such as DNA plasmids encoding genes2-4, small interfering RNA (siRNA) plasmids5, small synthetic RNA oligos6, and morpholino antisense oligonucleotides7 can be easily transfected into chicken embryos by electrop...

  20. Patients with polycystic ovary syndrome have successful embryo arrest

    OpenAIRE

    Yin, Baoli; Hao, Haoying; Wei, Duo; Song, Xiaobing; Xie, Juanke; Zhang, Cuilian

    2015-01-01

    In this retrospective study, we investigate the relationship between embryo arrest and polycystic ovary syndrome (PCOS) during in vitro fertilization-embryo transfer (IVF-ET). In this study, 667 subjects were enrolled, including 330 patients with PCOS and 337 subjects without PCOS. The subjects underwent in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) cycles at the Reproductive Medical Centre of Henan Provincial Hospital from January 2009 to December ...

  1. Marker Gene Delivery to Mature Wheat Embryos Via Particle Bombardment

    OpenAIRE

    Öktem, Hüseyin Avni; EYİDOGAN, Füsun (İnci); ERTUĞRUL, Fahriye; Yücel, Meral

    1999-01-01

    The possibility of transferring genes to mature wheat embryos ( Triticum aestivumL. and T. durum Desf.) via accelerated and DNA-coated tungsten particles was investigated. Mature embryos isolated from bread (cv. Atay) and durum (cv. Çakmak) wheat were utilised as targets for bombardment. DNA in the form of circular plasmid (pBSGUSINT) was precipitated on tungsten particles (ca. 2 mm diameter) using the calcium nitrate method. Mature embryos were bombarded by a microprocessor-controlled partic...

  2. Arabidopsis CDS blastp result: AK243152 [KOME

    Lifescience Database Archive (English)

    Full Text Available ase PP1 isozyme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains...P1 isozyme 4 (TOPP4) / phosphoprotein phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphat... a Ser/Thr protein phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 1e-154 ... ...AK243152 J100032N02 At2g39840.1 68415.m04893 serine/threonine protein phosphatase P

  3. Arabidopsis CDS blastp result: AK288069 [KOME

    Lifescience Database Archive (English)

    Full Text Available ase PP1 isozyme 4 (EC 3.1.3.16) {Arabidopsis thaliana}, phosphoprotein phosphatase 1 GI:166801 (Arabidopsis thaliana); contains...P1 isozyme 4 (TOPP4) / phosphoprotein phosphatase 1 identical to SP|P48484 Serine/threonine protein phosphat... a Ser/Thr protein phosphatase signature (PDOC00115); contains a metallo-phosphoesterase motif (QDOC50185) 6e-70 ... ...AK288069 J075158N05 At2g39840.1 68415.m04893 serine/threonine protein phosphatase P

  4. Biological damage induced by ionizing cosmic rays in dry Arabidopsis seeds.

    Science.gov (United States)

    Kranz, A R; Bork, U; Bucker, H; Reitz, G

    1990-01-01

    In September 1987 dry seeds containing embryos of the crucifer plant Arabidopsis thaliana (L.) Heynh, were flown in orbit for 13 days on the Kosmos 1887 satellite. The seeds were fixed on CNd detectors and stored in units of Biorack type I/O. One unit was exposed inside, another one outside the satellite. The temperature profile of the flown seeds inside the satellite was simulated on earth in an identical backup control sample (BC). An additional control (SC) was studied with the original seeds sample. By use of the CNd-detector, HZE-tracks were measured with a PC-assisted microscope. The biological damages were investigated by growing the seeds under controlled climatic conditions. The following biological endpoints of the cosmic radiation damage were studied: germination, radicle length, sublethality, morphological aberrations, flower development, tumorization, embryo lethality inside the siliques. The summarized damage (D) and the mutation frequencies of embyronic lethal genes were calculated. The following results were obtained: the damages increase significantly in orbit at all biological endpoints; germination and fiowerings especially, as well as embryo lethality of fruits and lethal mutation frequency, were maximum mostly for HZE-hit seeds. Additionally, an increase of damage was observed for the seeds of the outside-exposed Biorack in comparison to the inside ones, which was probably caused by less radiation shielding and free space vacuum. The significance of the results obtained is discussed with respect to stress and risk and, thus, the quality of the RBE-factors and heavy ionizing radiation all needed for the very definition of radiation protection standards in space. PMID:11537515

  5. Effect of zona pellucida on porcine parthenogenetically activated embryos

    DEFF Research Database (Denmark)

    Li, Rong; Liu, Ying; Li, Juan;

    2011-01-01

    The need for zona pellucida (ZP) during pre-implantation embryo development is still debated. In porcine parthenogenetically activated (PA) embryos, we have previously shown a different distribution in cell numbers on Day 6 blastocysts cultured with or without ZP (Li et al. 2010 Reprod. Fertil. Dev...... porcine PA embryos, especially at the timing of embryonic genome activation (5-cell stage). Furthermore, the zona pellucida can benefit the blastocyst formation and cryo-tolerance for PA embryos, perhaps by creating a more stable microenvironement....

  6. Classification of embryo sacs in the Eragrostis curvula Complex

    OpenAIRE

    T. B. Vorster; H. Liebenberg

    1984-01-01

    At each of 17 collecting points between Johannesburg and Brits in the Transvaal, three plants which belong to the  Eragrostis curvula Complex were collected and studied. A total o f 3 902 embryo sacs was examined in this sample. Of the embryo sacs examined, 3 306 were apomictic by means of diplospory, whereas 99 were sexual monosporic Polygonum-type embryo sacs. One hundred and nineteen embryo sacs were abnormal or divergent, and 378 were degenerated. There are indications that seasonal clima...

  7. Obtaining barley haploid embryos and seedlings using anther culture technique

    International Nuclear Information System (INIS)

    The effect of three barley genotypes (Igri, Arabi abiad, and Taqa 76), three irradiation doses (0, 5, and 10 Gy), and two media (FW, modified FW), on the number of formed embryos, and the ratio between regenerated embryos to green seedlings and albinos, were studied using anther culture. Also the study involved the compatibility between seedling morphology and chromosome number. results indicated significant differences among the genotypes, and media in callus and embryos formation and also in the ratio and albino seedlings. However, the effect of gamma rays dose was significant only on embryos regeneration. A high percentage of compatibility (90%) was obtained between the seedling morphology and chromosome number. (author)

  8. The DNA methylation events in normal and cloned rabbit embryos

    Institute of Scientific and Technical Information of China (English)

    TaoChen; Yan-LingZhang; YanJiang; Shu-ZhenLiu; HeideSchatten; Da-YuanChen; Qing-YuanSun

    2005-01-01

    To study the DNA methylation events in normal and cloned rabbit embryos, we investigated the methylation status of a satellite seqnence and the promoter region of a single-copy gene using bisulfite-sequencing technology. During normal rabbit embryo development, both sequences maintained hypermethylation status until the 8- to 16-cell stage when progressive demethylation took place. In cloned embryos, the single-copy gene promoter sequence was rapidly demethylated and preco-ciously de novo methylated, while the satellite sequence mainrained the donor-type methylation status in all examined stages. Our results indicate that unique sequences as well as satellitesequences may have aberrant methylation patterns in cloned embryos.

  9. Ultrastructural studies of Biomphalaria glabrata (Say, 1818) embryo

    International Nuclear Information System (INIS)

    Ultrastructural studies of Biomphalaria glabrata embryos (MOllusca: Gastropoda), and important snail vector of schistosomiasis has not been explored. In the present work it was evaluated a suitable electron microscopical technique for embryos processing. Promising results was obtained with double fixation in 1% glutaraldehyde plus 1% osmium tetroxide in 0.05 M cacodylate buffer (pH 7.4), preliminary staining overnight in 1% uranyl acetate and embedding in EPON or Polylite under vacuum. It was used embryos at young trochophore stage wich is characterized by active organogenesis. Some ultrastructural aspects of B. glabrata embryos cells are presented. (author)

  10. Correlation between embryo morphology and development and chromosomal complement

    Institute of Scientific and Technical Information of China (English)

    Vy Phan; Eva Littman; Dee Harris; Antoine La

    2014-01-01

    Objective: To analyze the correlation between embryo morphology and the chromosomal status using the array comparative genomic hybridization [array comparative genomic hybridization (a-CGH)] technique for screening 23 chromosome pairs in a single blastomere biopsy from Day 3 embryos. Methods: One thousand five hundred and fifty seven embryos were included from 203 cycle ICSI patients undergoing preimplantation genetic screening. The 23 chromosome pairs were analyzed by blastomere biopsy from day 3 embryos using a-CGH array method. Embryo development rate, fragmentation rate and chromosome status of the analyzed blastomeres were recorded and correlated with the aCGH results. Results: The incidence of chromosomal abnormalities was significantly higher in slow-and fast cleaving embryos at day 3 after insemination. The incidence of fragmentation and the type of fragmentation was associated with an increased incidence of chromosomal abnormalities. The symmetry of the blastomeres also correlated with the aneuploidy rates. Conclusions:Embryo development rate and morphological parameter such as degree, type of fragmentation and the symmetry of the blastomeres to a large extent reflect the cytogenetic status of the embryo and thus are important in the selection of embryos with the highest implantation potential.

  11. Interactions between co-expressed Arabidopsis sucrose transporters in the split-ubiquitin system

    Directory of Open Access Journals (Sweden)

    Lalonde Sylvie

    2003-03-01

    Full Text Available Abstract Background The Arabidopsis genome contains nine sucrose transporter paralogs falling into three clades: SUT1-like, SUT2 and SUT4. The carriers differ in their kinetic properties. Many transport proteins are known to exist as oligomers. The yeast-based split ubiquitin system can be used to analyze the ability of membrane proteins to interact. Results Promoter-GUS fusions were used to analyze the cellular expression of the three transporter genes in transgenic Arabidopsis plants. All three fusion genes are co-expressed in companion cells. Protein-protein interactions between Arabidopsis sucrose transporters were tested using the split ubiquitin system. Three paralogous sucrose transporters are capable of interacting as either homo- or heteromers. The interactions are specific, since a potassium channel and a glucose transporter did not show interaction with sucrose transporters. Also the biosynthetic and metabolizing enzymes, sucrose phosphate phosphatase and sucrose synthase, which were found to be at least in part bound to the plasma membrane, did not specifically interact with sucrose transporters. Conclusions The split-ubiquitin system provides a powerful tool to detect potential interactions between plant membrane proteins by heterologous expression in yeast, and can be used to screen for interactions with membrane proteins as baits. Like other membrane proteins, the Arabidopsis sucrose transporters are able to form oligomers. The biochemical approaches are required to confirm the in planta interaction.

  12. Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis

    International Nuclear Information System (INIS)

    Eleven loci that play a role in the synthesis of flavonoids in Arabidopsis are described. Mutations at these loci, collectively named transparent testa (tt), disrupt the synthesis of brown pigments in the seed coat (testa). Several of these loci (tt3, tt4, tt5 and ttg) are also required for the accumulation of purple anthocyanins in leaves and stems and one locus (ttg) plays additional roles in trichome and root hair development. Specific functions were previously assigned to tt1-7 and ttg. Here, the results of additional genetic, biochemical and molecular analyses of these mutants are described. Genetic map positions were determined for tt8, tt9 and tt10. Thin-layer chromatography identified tissue- and locus-specific differences in the flavonols and anthocyanidins synthesized by mutant and wild-type plants. It was found that UV light reveals distinct differences in the floral tissues of tt3, tt4, tt5, tt6 and ttg, even though these tissues are indistinguishable under visible light. Evidence was also uncovered that tt8 and ttg specifically affect dihydroflavonol reductase gene expression. A summary of these and previously published results are incorporated into an overview of the genetics of flavonoid biosynthesis in Arabidopsis

  13. Ethylene Inhibits Cell Proliferation of the Arabidopsis Root Meristem.

    Science.gov (United States)

    Street, Ian H; Aman, Sitwat; Zubo, Yan; Ramzan, Aleena; Wang, Xiaomin; Shakeel, Samina N; Kieber, Joseph J; Schaller, G Eric

    2015-09-01

    The root system of plants plays a critical role in plant growth and survival, with root growth being dependent on both cell proliferation and cell elongation. Multiple phytohormones interact to control root growth, including ethylene, which is primarily known for its role in controlling root cell elongation. We find that ethylene also negatively regulates cell proliferation at the root meristem of Arabidopsis (Arabidopsis thaliana). Genetic analysis indicates that the inhibition of cell proliferation involves two pathways operating downstream of the ethylene receptors. The major pathway is the canonical ethylene signal transduction pathway that incorporates CONSTITUTIVE TRIPLE RESPONSE1, ETHYLENE INSENSITIVE2, and the ETHYLENE INSENSITIVE3 family of transcription factors. The secondary pathway is a phosphorelay based on genetic analysis of receptor histidine kinase activity and mutants involving the type B response regulators. Analysis of ethylene-dependent gene expression and genetic analysis supports SHORT HYPOCOTYL2, a repressor of auxin signaling, as one mediator of the ethylene response and furthermore, indicates that SHORT HYPOCOTYL2 is a point of convergence for both ethylene and cytokinin in negatively regulating cell proliferation. Additional analysis indicates that ethylene signaling contributes but is not required for cytokinin to inhibit activity of the root meristem. These results identify key elements, along with points of cross talk with cytokinin and auxin, by which ethylene negatively regulates cell proliferation at the root apical meristem. PMID:26149574

  14. Effect of ambient light exposure of media and embryos on development and quality of porcine parthenogenetically activated embryos

    DEFF Research Database (Denmark)

    Li, Rong; Liu, Ying; Callesen, Henrik

    2015-01-01

    tested in two experiments: (1) ambient light on medium subsequently used for embryo in vitro development; and (2) ambient light exposure on activated oocytes before in vitro development. The results from Experiment 1 showed that exposure of culture medium to both types of ambient light decreased the....... In conclusion, exposure to ambient light can be harmful to embryo development, both when medium is exposed for a long period of time and, to a greater extent, when the embryo itself is exposed for >1 h. In practice, it is therefore recommended to protect both culture medium and porcine embryos......Light exposure is a common stress factor during in vitro handling of oocytes and embryos that originates from both microscope and ambient light. In the current study, the effect of two types of ambient light (daylight and laboratory light) on porcine parthenogenetically activated (PA) embryos was...

  15. Myosin II Dynamics during Embryo Morphogenesis

    Science.gov (United States)

    Kasza, Karen

    2013-03-01

    During embryonic morphogenesis, the myosin II motor protein generates forces that help to shape tissues, organs, and the overall body form. In one dramatic example in the Drosophila melanogaster embryo, the epithelial tissue that will give rise to the body of the adult animal elongates more than two-fold along the head-to-tail axis in less than an hour. This elongation is accomplished primarily through directional rearrangements of cells within the plane of the tissue. Just prior to elongation, polarized assemblies of myosin II accumulate perpendicular to the elongation axis. The contractile forces generated by myosin activity orient cell movements along a common axis, promoting local cell rearrangements that contribute to global tissue elongation. The molecular and mechanical mechanisms by which myosin drives this massive change in embryo shape are poorly understood. To investigate these mechanisms, we generated a collection of transgenic flies expressing variants of myosin II with altered motor function and regulation. We found that variants that are predicted to have increased myosin activity cause defects in tissue elongation. Using biophysical approaches, we found that these myosin variants also have decreased turnover dynamics within cells. To explore the mechanisms by which molecular-level myosin dynamics are translated into tissue-level elongation, we are using time-lapse confocal imaging to observe cell movements in embryos with altered myosin activity. We are utilizing computational approaches to quantify the dynamics and directionality of myosin localization and cell rearrangements. These studies will help elucidate how myosin-generated forces control cell movements within tissues. This work is in collaboration with J. Zallen at the Sloan-Kettering Institute.

  16. (Re)constructing embryos in stem cell research: exploring the meaning of embryos for people involved in fertility treatments.

    Science.gov (United States)

    Parry, Sarah

    2006-05-01

    The use of human embryos is a key controversy in public debates on stem cell research (SCR), yet little attention has been given to the context or sources from which embryos are obtained: people involved in fertility programmes. How they feel about the use of embryos in SCR, and what may lead them to agree or refuse to donate embryos, remains unexplored. In this paper, I investigate the views of people involved in fertility programmes who may be approached to donate their embryos for SCR, drawing on focus group discussions with two support groups in Scotland. I illustrate how people come to make particular decisions and what factors shape this, and show that participants' views are context-bound, borne out of lived experiences both within the clinic and wider society. In particular, the evidence highlights the importance of understanding their views of what constitutes a 'spare' embryo and what areas of medical research are considered potentially legitimate for using embryos. Peoples' understandings of embryos as potential lives, and the context in which embryos are created, have direct implications for their views about donating embryos for SCR. Attention is paid to how SCR further disrupts the teleology of embryos and undermines the narrative of life that suffuses the hopes of people undergoing fertility treatment. The paper also brings to the fore the sense of moral obligation experienced by participants who feel they have little means or power for influencing the topic and content of SCR. In this context, I suggest there is a need to explore further the views of people involved in fertility treatments in order to identify mechanisms for limiting the potential for coercion when SCR is embedded in and dependent on fertility practices. Debates about using embryos for SCR must, therefore, include the voices of those who thus remain marginalised. PMID:16289740

  17. Somatomedin inhibitors from the serum of diabetic rats: Effects on mouse embryos in whole embryo culture

    International Nuclear Information System (INIS)

    Somatomedin inhibitors (SIs) are elevated in the serum of diabetic rats and in human sera during certain disease states, suggesting that serum from human diabetes similarly has enhanced SI activity. A serum fraction of Mr = 800-1080 daltons obtained from diabetic rats and possessing SI activity, was added to the medium used to grow mouse conceptuses in whole embryo culture. Low concentrations of this SI caused malformations in embryos while their visceral yolk sacs (VYSs) were opaque and contained large vacuoles (vesicles) within the endoderm cells. DNA content and the incorporation of 3H-thymidine into DNA was reduced in both the embryo and its VYS. Concomitantly, the protein content of the embryo was decreased while that of the VYS was increased. Evidence from a variety of experiments indicted that the excess protein in the VYS was not due to de novo protein synthesis but to its sequestering of serum proteins. The failure of the normal VYS function of protein degradation was not due to an inhibition of the lysosomal enzyme, cathepsin B, indicating that some other aspect of protein degradation was affected by the presence of the SI

  18. Transfer of In Vitro Produced Sheep Embryos

    OpenAIRE

    BİRLER, Sema; PABUÇÇUOĞLU, Serhat; ATALLA, Hatem; ALKAN, Serhat; ÖZDAŞ, Özen Banu

    2002-01-01

    The objective of the present study was to transfer sheep embryos produced in vitro to recipient ewes. Ovaries were taken from slaughtered Kıvırcık ewes and transferred to the laboratory in phosphate buffered saline (PBS) at 30-35 ºC. The cumulus-oocyte complexes were obtained by slicing and washing 1-6 mm diameter follicles and matured for 24 h in medium 199 supplemented with sodium pyruvate, follicle stimulating hormone (FSH), luteinizing hormone (LH) and 10% fetal calf serum (FCS) at 38.5 º...

  19. Human embryo cloning prohibited in Hong Kong

    OpenAIRE

    Liu, Athena

    2005-01-01

    Since the birth of Dolly (the cloned sheep) in 1997, debates have arisen on the ethical and legal questions of cloning-for-biomedical-research (more commonly termed “therapeutic cloning”) and of reproductive cloning using human gametes. Hong Kong enacted the Human Reproductive Technology Ordinance (Cap 561) in 2000. Section 15(1)(e) of this Ordinance prohibits the “replacing of the nucleus of a cell of an embryo with a nucleus taken from any other cell,” i.e., nucleus substitution. Section 15...

  20. Development of teeth in chick embryos after mouse neural crest transplantations

    OpenAIRE

    Mitsiadis, Thimios A.; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

    2003-01-01

    Teeth were lost in birds 70–80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick ...

  1. Intrinsic Properties Guide Proximal Abducens and Oculomotor Nerve Outgrowth in Avian Embryos

    OpenAIRE

    Lance-Jones, Cynthia; Shah, Veeral; Noden, Drew M; Sours, Emily

    2012-01-01

    Proper movement of the vertebrate eye requires the formation of precisely patterned axonal connections linking cranial somatic motoneurons, located at defined positions in the ventral midbrain and hindbrain, with extraocular muscles. The aim of this research was to assess the relative contributions of intrinsic, population-specific properties and extrinsic, outgrowth site-specific cues during the early stages of abducens and oculomotor nerve development in avian embryos. This was accomplished...

  2. Pattern formation during gastrulation in the sea urchin embryo.

    Science.gov (United States)

    McClay, D R; Armstrong, N A; Hardin, J

    1992-01-01

    The sea urchin embryo follows a relatively simple cell behavioral sequence in its gastrulation movements. To form the mesoderm, primary mesenchyme cells ingress from the vegetal plate and then migrate along the basal lamina lining the blastocoel. The presumptive secondary mesenchyme and endoderm then invaginate from the vegetal pole of the embryo. The archenteron elongates and extends across the blastocoel until the tip of the archenteron touches and attaches to the opposite side of the blastocoel. Secondary mesenchyme cells, originally at the tip of the archenteron, differentiate to form a variety of structures including coelomic pouches, esophageal muscles, pigment cells and other cell types. After migration of the secondary mesenchyme cells from their original position at the tip of the archenteron, the endoderm fuses with an invagination of the ventral ectoderm (the stomodaem), to form the mouth and complete the process of gastrulation. A larval skeleton is made by primary mesenchyme cells during the time of archenteron and mouth formation. A number of experiments have established that these morphogenetic movements involve a number of cell autonomous behaviors plus a series of cell interactions that provide spatial, temporal and scalar information to cells of the mesoderm and endoderm. The cell autonomous behaviors can be demonstrated by the ability of micromeres or endoderm to perform their morphogenetic functions if either is isolated and grown in culture. The requirement for cell interactions has been demonstrated by manipulative experiments where it has been shown that axial information, temporal information, spatial information and scalar information is obtained by mesoderm and endoderm from other embryonic cells.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1299366

  3. Precocious germination and its regulation in embryos of triticale caryopses

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2014-02-01

    Full Text Available Triticale var. Lasko embryos, isolated from grain gathered at milk ripeness, the beginning of wax ripeness and at full ripeness, were allowed to germinate for 48 h on agar with glucose. The highest incorporation of tritiated adenosine into polyribosomal RNA during germination was found in the ribosome fractions from embryos of grain gathered at full ripeness, lower incorporation was in preparations from embryos of milk ripe grain and the lowest in preparations from embryos of wax ripe grain. Different tendencies were observed in respect to the synthesis of ribosomal proteins. The highest incorporation of 14C-amino acids into ribosomal proteins was found in preparations of ribosome fractions from embryos of milk ripe grain, lower in preparations of embryos from fully ripe grain, the lowest in preparations of embryos from wax ripe grain. ABA (10-4 M completely inhibited the external symptoms of germination of immature embryos, while its inhibition of the synthesis of polyribosomal RNA and ribosomal proteins was greater the more mature the embryos that were germinated. The greatest stimulation of precocious germination by exogenous BA and GA3 was demonstrated in the least mature embryos isolated from milk ripe grain. Under the influence of both stimulators, an increase of the proportion of polyribosomes in the total ribosome fraction occurred in this sample, as did a rise in the intensity of ribosomal protein synthesis. The incorporation of 3H-adenosine into polyribosomal RNA, however, was lower than in the control sample. The results obtained suggest that the regulation of precocious germination of triticale embryos by phyto-hormones is not directly related to transcription.

  4. Radioactive marking of proteins in cultured mouse embryos

    International Nuclear Information System (INIS)

    The purpose of this work was to build an in vitro test system, with which on the one hand postimplantation embryos of the mouse could be cultured without morphological of physiological damage and on the other hand their protein could be as highly marked as possible. With this radioactively marked proteins were to be won, which are optimally suited for a high separation by two-dimensional electrophoresis. In addition incubation and preparation methods were found for the ages of day 10, 11 and 12 of the embryonic development. With the use of 3H-marked amino acids in the culture medium it was determined that embryos without embryonic membranes, so-called N-embryos, built in more radioactivity into their proteins than the embryos with embryonic membranes, the so-called DAO-embryos or the DO-embryos. On the contrary, the embryos with intact blood circulation (DO-embryos) showed an even distribution of radioactive marker in their bodies. Since an even distribution of the marker in the embryo is a necessary prerequisite for a representative presentation of the proteins by 2DE, the DO-preparation was considered the best suited method. In order to increase the amount of radioactivity incorporated into the proteins of the DO-embryos, the concentration of the used isotope or the incubation length could be increased. A combination of both proved to be the best method. A 14C-marked amino acid mixture of 20 μCi/corresponds to 20 μl instead of the usual 150 μCi 3H-marked amino acids in a culture medium proved to be equally suitable. Notable changes which would have indicated a damaging affect of the used radioactivity or the in vitro culturing were not observed. The achieved methodical conditions were used for the presentation of the embryo proteins by two-dimensional electrophoresis and fluorography. (orig./MG)

  5. A method for detecting MFO induction by Japanese pulp mill effluents with chick embryo

    Energy Technology Data Exchange (ETDEWEB)

    Tatarazako, Norihisa; Kamaya, Yasushi [Japan Pulp and Paper Research Inst. Inc., Tokodai, Tsukuba (Japan)

    1995-12-31

    As a biomarker of physiological responses in fish exposed to pulp and paper mill effluents, mixed function oxygenase (MFO) induction has been investigated by many researchers. The induction and/or inhibition of MFOs is generally affected by various factors of fish such as species, maturity, sex, size and spawning status, and by other environmental variables. Therefore, the method demands technical skills to get a constant result. In addition, the test is costly and also time consuming. In this paper, the authors propose a MFOs induction method using chick embryo, instead of fish, for the assessment of pulp mill effluent. The merits of this method are as follows; inexpensive and commercially available test organisms, easy maintenance of the organisms, no feeding, high uniformity of the developing stage, sensitive responses to xenobiotics, low sample volume requirements, easy testing of various samples at one time and minimal training. P450 1A1 has been found in the microsome of chick embryo. Metabolic function of the P450 1A1 can be regarded basically the same as that of fish. Small amount of xenobiotics, about 100 {micro}l, were injected into the air chamber of 16-day-old chick embryos. Liver microsomes were isolated 48 h after administration. Ethoxyresorufin-O-deethylase (EROD) activity was determined by the direct fluorimetric method. Using the chick embryo method, the authors analyzed various chloro-organics, model bleached kraft pulp mill effluents, model black liquor and several total effluents of Japanese pulp mills. Methylcholanthrene and 2,3,7,8-TCDD were used as positive controls. In this paper, the authors will report the details of the chick embryo method and also some results of the assessment using the method.

  6. Bilirubin and heme as growth inhibitors of chicken embryos in ovo.

    Science.gov (United States)

    Vassilopoulou-Sellin, R; Foster, P; Oyedeji, C O

    1990-06-01

    The increased morbidity during pregnancies complicated by hematologic or liver disease has generally been attributed to the metabolic abnormalities of the illness itself. Because tetrapyrrole concentrations are elevated in these conditions, we introduced bilirubin or heme (prepared as 10 mM solutions) into the air sac of fertilized chicken eggs to study their effect on the growth of normal chicken embryos. In 9-d eggs, the injection of 0.06 mL heme resulted in significant embryo growth inhibition as indicated by overall wt (91 +/- 3% versus control), tibia length (84 +/- 2%), tibia wt (81 +/- 3%), femur length (88 +/- 1%), and femur wt (78 +/- 3%); doses greater than 0.10 mL resulted in substantial fetal losses. The injection of 0.06 mL bilirubin into the same-age eggs also resulted in less than normal tibia length (87 +/- 2% versus control), tibia wt (75 +/- 4%), femur length (91 +/- 2%), and femur wt (81 +/- 3%); larger doses resulted in more pronounced growth inhibition, but fetal losses were less common than with heme. Older chick embryos (12-d) appeared more resistant to the effects of bilirubin: 0.15 mL bilirubin inhibited only tibia and femur wt; larger doses were required to significantly suppress the other growth parameters. The same-age chicken embryos, however, remained exquisitely sensitive to heme; 0.05 mL resulted in less than normal whole embryo wt (88 +/- 2% versus control), tibia length (80 +/- 1%), tibia wt (76 +/- 1%), femur length (78 +/- 1%), and femur wt (77 +/- 1%).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2356106

  7. Molecular asymmetry in the 8-cell stage Xenopus tropicalis embryo described by single blastomere transcript sequencing.

    Science.gov (United States)

    De Domenico, Elena; Owens, Nick D L; Grant, Ian M; Gomes-Faria, Rosa; Gilchrist, Michael J

    2015-12-15

    Correct development of the vertebrate body plan requires the early definition of two asymmetric, perpendicular axes. The first axis is established during oocyte maturation, and the second is established by symmetry breaking shortly after fertilization. The physical processes generating the second asymmetric, or dorsal-ventral, axis are well understood, but the specific molecular determinants, presumed to be maternal gene products, are poorly characterized. Whilst enrichment of maternal mRNAs at the animal and vegetal poles in both the oocyte and the early embryo has been studied, little is known about the distribution of maternal mRNAs along either the dorsal-ventral or left-right axes during the early cleavage stages. Here we report an unbiased analysis of the distribution of maternal mRNA on all axes of the Xenopus tropicalis 8-cell stage embryo, based on sequencing of single blastomeres whose positions within the embryo are known. Analysis of pooled data from complete sets of blastomeres from four embryos has identified 908 mRNAs enriched in either the animal or vegetal blastomeres, of which 793 are not previously reported as enriched. In contrast, we find no evidence for asymmetric distribution along either the dorsal-ventral or left-right axes. We confirm that animal pole enrichment is on average distinctly lower than vegetal pole enrichment, and that considerable variation is found between reported enrichment levels in different studies. We use publicly available data to show that there is a significant association between genes with human disease annotation and enrichment at the animal pole. Mutations in the human ortholog of the most animally enriched novel gene, Slc35d1, are causative for Schneckenbecken dysplasia, and we show that a similar phenotype is produced by depletion of the orthologous protein in Xenopus embryos. PMID:26100918

  8. Assay for the detection of non-lethal changes that are expressed as a proliferative disadvantage in mouse (Mus musculus) embryo aggregation chimberas

    International Nuclear Information System (INIS)

    This study demonstrates the potential utility of the chimera embryo assay in measuring the effects of a variety of non-lethal, potentially hazardous environmental agents on normal mammalian embryonic cells. The two major findings to have emerged from this investigation are, (1) relative cellular contribution per embryo in chimeras was found to depend on the strain of the partner embryo and this relationship apparently does not require cell to cell contact between the partner embryos of the chimera and is already apparent after only two cell cycles; and (2) within the same outbred strain, exposure of one partner embryo in the chimera to either X-irradiation or chlorpromazine, at dose levels that were lower than those previously found to be embryotoxic; such toxicity was revealed as a proliferative disadvantage that was also evident after only 2 cell cycles. Partner embryos in the chimera were distinguished by labelling one of them with the fluorescent dye, fluorescein isothiocyanate (FITC), which was shown to have no detrimental effects on the proliferation rate of the labelled embryos

  9. TERATOGENICITY OF CYCLOPHOSPHAMIDE IN A COUPLED MICROSOMAL ACTIVATING/EMBRYO CULTURE SYSTEM

    Science.gov (United States)

    Using the coupled microsomal activating/embryo culture system, in vitro experiments were performed to establish the role of metabolism in the embryo toxicity and teratogenicity of cyclophosphamide. Cyclophosphamide in the coupled microsomal activating/embryo culture system produc...

  10. Mitochondrial gamma carbonic anhydrases are required for complex I assembly and plant reproductive development.

    Science.gov (United States)

    Fromm, Steffanie; Braun, Hans-Peter; Peterhansel, Christoph

    2016-07-01

    Complex I of the mitochondrial electron transport chain (mETC) in plants contains an extra domain that is made up from proteins homologous to prokaryotic gamma-carbonic anhydrases (γCA). This domain has been suggested to participate in complex I assembly or to support transport of mitochondrial CO2 to the chloroplast. Here, we generated mutants lacking CA1 and CA2 - two out of three CA proteins in Arabidopsis thaliana. Double mutants were characterized at the developmental and physiological levels. Furthermore, the composition and activity of the mETC were determined, and mutated CA versions were used for complementation assays. Embryo development of double mutants was strongly delayed and seed development stopped before maturation. Mutant plants could only be rescued on sucrose media, showed severe stress symptoms and never produced viable seeds. By contrast, callus cultures were only slightly affected in growth. Complex I was undetectable in the double mutants, but complex II and complex IV were upregulated concomitant with increased oxygen consumption in mitochondrial respiration. Ectopic expression of inactive CA variants was sufficient to complement the mutant phenotype. Data indicate that CA proteins are structurally required for complex I assembly and that reproductive development is dependent on the presence of complex I. PMID:26889912

  11. Arabidopsis CDS blastp result: AK066771 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066771 J013083K07 At1g01170.1 ozone-responsive stress-related protein, putative s...imilar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 2e-29 ...

  12. Arabidopsis CDS blastp result: AK059353 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059353 001-026-D01 At1g01170.1 ozone-responsive stress-related protein, putative ...similar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 2e-29 ...

  13. Arabidopsis CDS blastp result: AK059160 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059160 001-023-D05 At1g01170.1 ozone-responsive stress-related protein, putative ...similar to stress-related ozone-induced protein AtOZI1 (GI:790583) [Arabidopsis thaliana]; contains 1 predicted transmembrane domain; 3e-28 ...

  14. Arabidopsis CDS blastp result: AK242849 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242849 J090072M15 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  15. Arabidopsis CDS blastp result: AK288959 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288959 J090084E19 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  16. Arabidopsis CDS blastp result: AK243008 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243008 J090097H12 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  17. Arabidopsis CDS blastp result: AK288072 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288072 J075161I05 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  18. Arabidopsis CDS blastp result: AK243178 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243178 J100036P15 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  19. Arabidopsis CDS blastp result: AK243505 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243505 J100074N19 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...

  20. Arabidopsis CDS blastp result: AK287577 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287577 J065037N08 At1g68370.1 68414.m07809 gravity -responsive protein / altered response to gravity ... ty protein (ARG1) identical to Altered Response to Gravity ... [Arabidopsis thaliana] GI:4249662; contains Pfam p ...