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  1. The mitochondrial sulfur dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 is required for amino acid catabolism during carbohydrate starvation and embryo development in Arabidopsis.

    Science.gov (United States)

    Krüßel, Lena; Junemann, Johannes; Wirtz, Markus; Birke, Hannah; Thornton, Jeremy D; Browning, Luke W; Poschet, Gernot; Hell, Rüdiger; Balk, Janneke; Braun, Hans-Peter; Hildebrandt, Tatjana M

    2014-05-01

    The sulfur dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 (ETHE1) catalyzes the oxidation of persulfides in the mitochondrial matrix and is essential for early embryo development in Arabidopsis (Arabidopsis thaliana). We investigated the biochemical and physiological functions of ETHE1 in plant metabolism using recombinant Arabidopsis ETHE1 and three transfer DNA insertion lines with 50% to 99% decreased sulfur dioxygenase activity. Our results identified a new mitochondrial pathway catalyzing the detoxification of reduced sulfur species derived from cysteine catabolism by oxidation to thiosulfate. Knockdown of the sulfur dioxygenase impaired embryo development and produced phenotypes of starvation-induced chlorosis during short-day growth conditions and extended darkness, indicating that ETHE1 has a key function in situations of high protein turnover, such as seed production and the use of amino acids as alternative respiratory substrates during carbohydrate starvation. The amino acid profile of mutant plants was similar to that caused by defects in the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase complex and associated dehydrogenases. Thus, in addition to sulfur amino acid catabolism, ETHE1 also affects the oxidation of branched-chain amino acids and lysine.

  2. Efficient and rapid isolation of early-stage embryos from Arabidopsis thaliana seeds

    OpenAIRE

    Raissig, Michael T; Gagliardini, Valeria; Jaenisch, Johan; Grossniklaus, Ueli; Baroux, Célia

    2013-01-01

    In flowering plants, the embryo develops within a nourishing tissue - the endosperm - surrounded by the maternal seed integuments (or seed coat). As a consequence, the isolation of plant embryos at early stages (1 cell to globular stage) is technically challenging due to their relative inaccessibility. Efficient manual dissection at early stages is strongly impaired by the small size of young Arabidopsis seeds and the adhesiveness of the embryo to the surrounding tissues. Here, we describe a ...

  3. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Science.gov (United States)

    Raissig, Michael T; Bemer, Marian; Baroux, Célia; Grossniklaus, Ueli

    2013-01-01

    Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA) and PHERES1 (PHE1), which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1) gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs) and one paternally expressed gene (PEG) in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2) but not the DNA METHYLTRANSFERASE1 (MET1) is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  4. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Directory of Open Access Journals (Sweden)

    Michael T Raissig

    Full Text Available Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA and PHERES1 (PHE1, which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1 gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs and one paternally expressed gene (PEG in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2 but not the DNA METHYLTRANSFERASE1 (MET1 is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  5. Local auxin sources orient the apical-basal axis in Arabidopsis embryos.

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    Robert, Hélène S; Grones, Peter; Stepanova, Anna N; Robles, Linda M; Lokerse, Annemarie S; Alonso, Jose M; Weijers, Dolf; Friml, Jiří

    2013-12-16

    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 to generate an asymmetric auxin response that specifies the embryonic apical-basal axis. The auxin flow directionality depends on the polarized subcellular localization of PIN-FORMED (PIN) auxin transporters. It remains unknown which mechanisms and spatial cues guide cell polarization and axis orientation in early embryos. Herein, we provide conceptually novel insights into the formation of embryonic axis in Arabidopsis by identifying a crucial role of localized tryptophan-dependent auxin biosynthesis. Local auxin production at the base of young embryos and the accompanying PIN7-mediated auxin flow toward the proembryo are required for the apical auxin response maximum and the specification of apical embryonic structures. Later in embryogenesis, the precisely timed onset of localized apical auxin biosynthesis mediates PIN1 polarization, basal auxin response maximum, and specification of the root pole. Thus, the tight spatiotemporal control of distinct local auxin sources provides a necessary, non-cell-autonomous trigger for the coordinated cell polarization and subsequent apical-basal axis orientation during embryogenesis and, presumably, also for other polarization events during postembryonic plant life.

  6. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis.

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    Lardizabal, K D; Metz, J G; Sakamoto, T; Hutton, W C; Pollard, M R; Lassner, M W

    2000-03-01

    Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a beta-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua. (13)C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

  7. Plastidial NAD-dependent malate dehydrogenase is critical for embryo development and heterotrophic metabolism in Arabidopsis.

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    Beeler, Seraina; Liu, Hung-Chi; Stadler, Martha; Schreier, Tina; Eicke, Simona; Lue, Wei-Ling; Truernit, Elisabeth; Zeeman, Samuel C; Chen, Jychian; Kötting, Oliver

    2014-03-01

    In illuminated chloroplasts, one mechanism involved in reduction-oxidation (redox) homeostasis is the malate-oxaloacetate (OAA) shuttle. Excess electrons from photosynthetic electron transport in the form of nicotinamide adenine dinucleotide phosphate, reduced are used by NADP-dependent malate dehydrogenase (MDH) to reduce OAA to malate, thus regenerating the electron acceptor NADP. NADP-MDH is a strictly redox-regulated, light-activated enzyme that is inactive in the dark. In the dark or in nonphotosynthetic tissues, the malate-OAA shuttle was proposed to be mediated by the constitutively active plastidial NAD-specific MDH isoform (pdNAD-MDH), but evidence is scarce. Here, we reveal the critical role of pdNAD-MDH in Arabidopsis (Arabidopsis thaliana) plants. A pdnad-mdh null mutation is embryo lethal. Plants with reduced pdNAD-MDH levels by means of artificial microRNA (miR-mdh-1) are viable, but dark metabolism is altered as reflected by increased nighttime malate, starch, and glutathione levels and a reduced respiration rate. In addition, miR-mdh-1 plants exhibit strong pleiotropic effects, including dwarfism, reductions in chlorophyll levels, photosynthetic rate, and daytime carbohydrate levels, and disordered chloroplast ultrastructure, particularly in developing leaves, compared with the wild type. pdNAD-MDH deficiency in miR-mdh-1 can be functionally complemented by expression of a microRNA-insensitive pdNAD-MDH but not NADP-MDH, confirming distinct roles for NAD- and NADP-linked redox homeostasis.

  8. PS2 integrin requirements in Drosophila embryo and wing morphogenesis.

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    Brabant, M C; Brower, D L

    1993-05-01

    The Drosophila inflated (if) gene encodes the alpha PS2 subunit of the PS integrins. We describe the generation of new if mutations, their lethal embryonic phenotype, and experiments that examine the spatial and temporal requirements for integrins in adult wing morphogenesis. Embryos hemizygous for either new allele, ifA7 or ifB2, make reduced amounts of alpha PS2. In a variety of genetic tests, these alleles behave similarly to ifk27e, which makes no detectable alpha PS2, and all three alleles display the same embryonic phenotype. We therefore conclude that all of the lethal alleles retain little or no wild-type alpha PS2 function. As seen for strong mutations at the myospheroid (mys) locus, which encodes the beta PS integrin subunit, if mutants show extreme defects in somatic muscle attachments and in midgut morphogenesis. Unlike mys, however, there is no dorsal herniation of the if mutant embryos. With respect to wing morphogenesis, clonal analysis experiments demonstrate that if+ function is required only in cells of the ventral wing surface. We have rescued the wing blister phenotype of double mutants for the hypomorphic mysnj42 and if3 alleles using a heat shock-inducible mys+ transgene. By varying times of transgene induction, we find that integrin function is required from very early in metamorphosis until at least the last 24-48 hr of wing development.

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

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    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.

  10. 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.

  11. Mechanical constraints imposed by 3D cellular geometry and arrangement modulate growth patterns in the Arabidopsis embryo.

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    Bassel, George W; Stamm, Petra; Mosca, Gabriella; Barbier de Reuille, Pierre; Gibbs, Daniel J; Winter, Robin; Janka, Ales; Holdsworth, Michael J; Smith, Richard S

    2014-06-10

    Morphogenesis occurs in 3D space over time and is guided by coordinated gene expression programs. Here we use postembryonic development in Arabidopsis plants to investigate the genetic control of growth. We demonstrate that gene expression driving the production of the growth-stimulating hormone gibberellic acid and downstream growth factors is first induced within the radicle tip of the embryo. The center of cell expansion is, however, spatially displaced from the center of gene expression. Because the rapidly growing cells have very different geometry from that of those at the tip, we hypothesized that mechanical factors may contribute to this growth displacement. To this end we developed 3D finite-element method models of growing custom-designed digital embryos at cellular resolution. We used this framework to conceptualize how cell size, shape, and topology influence tissue growth and to explore the interplay of geometrical and genetic inputs into growth distribution. Our simulations showed that mechanical constraints are sufficient to explain the disconnect between the experimentally observed spatiotemporal patterns of gene expression and early postembryonic growth. The center of cell expansion is the position where genetic and mechanical facilitators of growth converge. We have thus uncovered a mechanism whereby 3D cellular geometry helps direct where genetically specified growth takes place.

  12. 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.

  13. The importance of localized auxin production for morphogenesis of reproductive organs and embryos in Arabidopsis.

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    Robert, Hélène S; Crhak Khaitova, Lucie; Mroue, Souad; Benková, Eva

    2015-08-01

    Plant sexual reproduction involves highly structured and specialized organs: stamens (male) and gynoecia (female, containing ovules). These organs synchronously develop within protective flower buds, until anthesis, via tightly coordinated mechanisms that are essential for effective fertilization and production of viable seeds. The phytohormone auxin is one of the key endogenous signalling molecules controlling initiation and development of these, and other, plant organs. In particular, its uneven distribution, resulting from tightly controlled production, metabolism and directional transport, is an important morphogenic factor. In this review we discuss how developmentally controlled and localized auxin biosynthesis and transport contribute to the coordinated development of plants' reproductive organs, and their fertilized derivatives (embryos) via the regulation of auxin levels and distribution within and around them. Current understanding of the links between de novo local auxin biosynthesis, auxin transport and/or signalling is presented to highlight the importance of the non-cell autonomous action of auxin production on development and morphogenesis of reproductive organs and embryos. An overview of transcription factor families, which spatiotemporally define local auxin production by controlling key auxin biosynthetic enzymes, is also presented.

  14. The CUP-SHAPED COTYLEDON3 gene is required for boundary and shoot meristem formation in Arabidopsis

    DEFF Research Database (Denmark)

    Vroemen, Casper W; Mordhorst, Andreas P; Albrecht, Cathy

    2003-01-01

    From an enhancer trap screen for genes expressed in Arabidopsis embryos, we identified a gene expressed from the octant stage onward in the boundary between the two presumptive cotyledons and in a variety of postembryonic organ and meristem boundaries. This gene, CUP-SHAPED COTYLEDON3 (CUC3...

  15. Loss of LORELEI function in the pistil delays initiation but does not affect embryo development in Arabidopsis thaliana

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    Tsukamoto, Tatsuya

    2010-01-01

    Double fertilization, uniquely observed in plants, requires successful sperm cell delivery by the pollen tube to the female gametophyte, followed by migration, recognition and fusion of the two sperm cells with two female gametic cells. The female gametophyte not only regulates these steps but also controls the subsequent initiation of seed development. Previously, we reported that loss of LORELEI, which encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein, in the female reproductive tissues causes a delay in initiation of seed development. From these studies, however, it was unclear if embryos derived from fertilization of lre-5 gametophytes continued to lag behind wild-type during seed development. Additionally, it was not determined if the delay in initiation of seed development had any lingering effects during seed germination. Finally, it was not known if loss of LORELEI function affects seedling development given that LORELEI is expressed in eight-day-old seedlings. Here, we showed that despite a delay in initiation, lre-5/lre-5 embryos recover, becoming equivalent to the developing wild-type embryos beginning at 72 hours after pollination. Additionally, lre-5/lre-5 seed germination, and seedling and root development are indistinguishable from wild-type indicating that loss of LORELEI is tolerated, at least under standard growth conditions, in vegetative tissues. PMID:21051955

  16. Loss of LORELEI function in the pistil delays initiation but does not affect embryo development in Arabidopsis thaliana.

    Science.gov (United States)

    Tsukamoto, Tatsuya; Palanivelu, Ravishankar

    2010-11-01

    Double fertilization, uniquely observed in plants, requires successful sperm cell delivery by the pollen tube to the female gametophyte, followed by migration, recognition and fusion of the two sperm cells with two female gametic cells. The female gametophyte not only regulates these steps but also controls the subsequent initiation of seed development. Previously, we reported that loss of LORELEI, which encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein, in the female reproductive tissues causes a delay in initiation of seed development. From these studies, however, it was unclear if embryos derived from fertilization of lre-5 gametophytes continued to lag behind wild type during seed development. Additionally, it was not determined if the delay in initiation of seed development had any lingering effects during seed germination. Finally, it was not known if loss of LORELEI function affects seedling development given that LORELEI is expressed in eight-day-old seedlings. Here, we showed that despite a delay in initiation, lre-5/lre-5 embryos recover, becoming equivalent to the developing wild-type embryos beginning at 72 hours after pollination. Additionally, lre-5/lre-5 seed germination, and seedling and root development are indistinguishable from wild type indicating that loss of LORELEI is tolerated, at least under standard growth conditions, in vegetative tissues.

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

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    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.

  18. 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.

  19. 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

  20. 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.

  1. Primary cilia are not required for normal canonical Wnt signaling in the mouse embryo.

    Directory of Open Access Journals (Sweden)

    Polloneal Jymmiel R Ocbina

    Full Text Available Sonic hedgehog (Shh signaling in the mouse requires the microtubule-based organelle, the primary cilium. The primary cilium is assembled and maintained through the process of intraflagellar transport (IFT and the response to Shh is blocked in mouse mutants that lack proteins required for IFT. Although the phenotypes of mouse IFT mutants do not overlap with phenotypes of known Wnt pathway mutants, recent studies report data suggesting that the primary cilium modulates responses to Wnt signals.We therefore carried out a systematic analysis of canonical Wnt signaling in mutant embryos and cells that lack primary cilia because of loss of the anterograde IFT kinesin-II motor (Kif3a or IFT complex B proteins (Ift172 or Ift88. We also analyzed mutant embryos with abnormal primary cilia due to defects in retrograde IFT (Dync2h1. The mouse IFT mutants express the canonical Wnt target Axin2 and activate a transgenic canonical Wnt reporter, BAT-gal, in the normal spatial pattern and to the same quantitative level as wild type littermates. Similarly, mouse embryonic fibroblasts (MEFs derived from IFT mutants respond normally to added Wnt3a. The switch from canonical to non-canonical Wnt also appears normal in IFT mutant MEFs, as both wild-type and mutant cells do not activate the canonical Wnt reporter in the presence of both Wnt3a and Wnt5a.We conclude that loss of primary cilia or defects in retrograde IFT do not affect the response of the midgestation embryo or embryo-derived fibroblasts to Wnt ligands.

  2. An Arabidopsis thaliana high-affinity molybdate transporter required for efficient uptake of molybdate from soil

    OpenAIRE

    Tomatsu, Hajime; Takano, Junpei; Takahashi, Hideki; Watanabe-Takahashi, Akiko; Shibagaki, Nakako; Fujiwara, Toru

    2007-01-01

    Molybdenum (Mo) is a trace element essential for living organisms, however no molybdate transporter has been identified in eukaryotes. Here, we report the identification of a molybdate transporter, MOT1, from Arabidopsis thaliana. MOT1 is expressed in both roots and shoots, and the MOT1 protein is localized, in part, to plasma membranes and to vesicles. MOT1 is required for efficient uptake and translocation of molybdate and for normal growth under conditions of limited molybdate supply. Kine...

  3. GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome branching through gibberellic acid signaling in Arabidopsis.

    Science.gov (United States)

    An, Lijun; Zhou, Zhongjing; Su, Sha; Yan, An; Gan, Yinbo

    2012-02-01

    Cell differentiation generally corresponds to the cell cycle, typically forming a non-dividing cell with a unique differentiated morphology, and Arabidopsis trichome is an excellent model system to study all aspects of cell differentiation. Although gibberellic acid is reported to be involved in trichome branching in Arabidopsis, the mechanism for such signaling is unclear. Here, we demonstrated that GLABROUS INFLORESCENCE STEMS (GIS) is required for the control of trichome branching through gibberellic acid signaling. The phenotypes of a loss-of-function gis mutant and an overexpressor showed that GIS acted as a repressor to control trichome branching. Our results also show that GIS is not required for cell endoreduplication, and our molecular and genetic study results have shown that GIS functions downstream of the key regulator of trichome branching, STICHEL (STI), to control trichome branching through the endoreduplication-independent pathway. Furthermore, our results also suggest that GIS controls trichome branching in Arabidopsis through two different pathways and acts either upstream or downstream of the negative regulator of gibbellic acid signaling SPINDLY (SPY).

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

    OpenAIRE

    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 acid (SA)-independent signalling pathway that requires an intact response to the plant hormones jasmonic acid (JA) and ethylene (ET). Arabidopsis accessions RLD1 and Ws-0 fail to express ISR agains...

  5. Porcupine homolog is required for canonical Wnt signaling and gastrulation in mouse embryos.

    Science.gov (United States)

    Biechele, Steffen; Cox, Brian J; Rossant, Janet

    2011-07-15

    Wnt signaling plays important roles in development and disease. The X-chromosomal Porcupine homolog gene (Porcn) encodes an evolutionary conserved member of the membrane bound O-acyl transferase (MBOAT) superfamily that has been shown to be required for the palmitoylation and secretion of Wnt3a, a mechanism that has been suggested to be conserved for all mammalian Wnt ligands. PORCN mutations in humans cause Focal Dermal Hypoplasia (FDH), a disorder causing developmental defects in heterozygous females and embryonic lethality in hemizygous males. In this study, Porcn mutant mouse embryonic stem (ES) cells were used to analyze the role of Porcn in mammalian embryonic development. In vitro, we show an exclusive requirement for Porcn in Wnt secreting cells and further, that any of the four Porcn isoforms is sufficient to allow for the secretion of functional Wnt3a. Embryos generated by aggregation of Porcn mutant ES cells with wildtype embryos fail to complete gastrulation in vivo, but remain in an epiblast-like state, similar to Wnt3 and Gpr177/Wls mutants. Consistent with this phenotype, in vitro differentiated mutant ES cells fail to generate endoderm and mesoderm derivatives. Taken together, these data confirm the importance of Porcn for Wnt secretion and gastrulation and suggest that disruption of early development underlies the male lethality of human PORCN mutants.

  6. 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.

  7. Genetic analysis of the Arabidopsis protein kinases MAP3Kε1 and MAP3Kε2 indicates roles in cell expansion and embryo development.

    Science.gov (United States)

    Chaiwongsar, Suraphon; Strohm, Allison K; Su, Shih-Heng; Krysan, Patrick J

    2012-01-01

    MAP3Kε1 and MAP3Kε2 are a pair of Arabidopsis thaliana genes that encode protein kinases related to cdc7p from Saccharomyces cerevisiae. We have previously shown that the map3kε1;map3kε2 double-mutant combination causes pollen lethality. In this study, we have used an ethanol-inducible promoter construct to rescue this lethal phenotype and create map3kε1(-/-);map3kε2(-/-) double-mutant plants in order to examine the function of these genes in the sporophyte. These rescued double-mutant plants carry a yellow fluorescent protein (YFP)-MAP3Kε1 transgene under the control of the alcohol-inducible AlcA promoter from Aspergillus nidulans. The double-mutant plants were significantly smaller and had shorter roots than wild-type when grown in the absence of ethanol treatment. Microscopic analysis indicated that cell elongation was reduced in the roots of the double-mutant plants and cell expansion was reduced in rosette leaves. Treatment with ethanol to induce expression of YFP-MAP3Kε1 largely rescued the leaf phenotypes. The double-mutant combination also caused embryos to arrest in the early stages of development. Through the use of YFP reporter constructs we determined that MAP3Kε1 and MAP3Kε2 are expressed during embryo development, and also in root tissue. Our results indicate that MAP3Kε1 and MAP3Kε2 have roles outside of pollen development and that these genes affect several aspects of sporophyte development.

  8. The structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo NAD(+) content in OPI-induced teratogenesis in chickens.

    Science.gov (United States)

    Seifert, Josef

    2016-05-01

    The objective of this study was to determine the structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo nicotinamide adenine dinucleotide (NAD(+)) content in OPI-induced teratogenesis and compare them with those needed for OPI inhibition of yolk sac membrane kynurenine formamidase (KFase), the proposed primary target for OPI teratogens in chicken embryos. The comparative molecular field analysis (COMFA) of three-dimensional quantitative structure-activity relationship (3D QSAR) revealed the electrostatic and steric fields as good predictors of OPI structural requirements to reduce NAD(+) content in chicken embryos. The dominant electrostatic interactions were localized at nitrogen-1, nitrogen-3, nitrogen of 2-amino substituent of the pyrimidinyl of pyrimidinyl phosphorothioates, and at the oxygen of crotonamide carbonyl in crotonamide phosphates. Bulkiness of the substituents at carbon-6 of the pyrimidinyls and/or N-substituents of crotonamides was the steric structural component that contributed to superiority of those OPI for reducing embryonic NAD(+) levels. Both electrostatic and steric requirements are similar to those defined in our previous study for OPI inhibition of chicken embryo yolk sac membrane KFase. The findings of this study provide another piece of evidence for the cause-and-effect relationship between yolk sac membrane KFase inhibition and reduced embryo NAD(+) content in NAD-associated OPI-induced teratogenesis in chickens.

  9. PHOSPHATIDYLSERINE SYNTHASE1 is Required for Inflorescence Meristem and Organ Development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Chengwu Liu; Hengfu Yin; Peng Gao; Xiaohe Hu; Jun Yang; Zhongchi Liu; Xiangdong Fu

    2013-01-01

    Phosphatidylserine (PS),a quantitatively minor membrane phospholipid,is involved in many biological processes besides its role in membrane structure.One PS synthesis gene,PHOSPHATIDYLSERINE SYNTHASE1 (PSS1),has been discovered to be required for microspore development in Arabidopsis thaliana L.but how PSS1 affects postembryonic development is still largely unknown.Here,we show that PSS1 is also required for inflorescence meristem and organ development in Arabidopsis.Disruption of PSS1 causes severe dwarfism,smaller lateral organs and reduced size of inflorescence meristem.Morphological and molecular studies suggest that both cell division and cell elongation are affected in the pss1-1 mutant.RNA in situ hybridization and promoter GUS analysis show that expression of both WUSCHEL (WUS) and CLAVATA3 (CLV3) depend on PSS1.Moreover,the defect in meristem maintenance is recovered and the expression of WUS and CLV3 are restored in the pss1-1 clv1-1 double mutant.Both SHOOTSTEMLESS (STM) and BREVIPEDICELLUS (BP) are upregulated,and auxin distribution is disrupted in rosette leaves of pss1-1.However,expression of BP,which is also a regulator of internode development,is lost in the pss1-1 inflorescence stem.Our data suggest that PSS1 plays essential roles in inflorescence meristem maintenance through the WUS-CLV pathway,and in leaf and internode development by differentially regulating the class Ⅰ KNOX genes.

  10. A chloroplast lipoxygenase is required for wound-induced jasmonic acid accumulation in Arabidopsis.

    Science.gov (United States)

    Bell, E; Creelman, R A; Mullet, J E

    1995-09-12

    Plant lipoxygenases are thought to be involved in the biosynthesis of lipid-derived signaling molecules. The potential involvement of a specific Arabidopsis thaliana lipoxygenase isozyme, LOX2, in the biosynthesis of the plant growth regulators jasmonic acid (JA) and abscisic acid was investigated. Our characterization of LOX2 indicates that the protein is targeted to chloroplasts. The physiological role of this chloroplast lipoxygenase was analyzed in transgenic plants where cosuppression reduced LOX2 accumulation. The reduction in LOX2 levels caused no obvious changes in plant growth or in the accumulation of abscisic acid. However, the wound-induced accumulation of JA observed in control plants was absent in leaves of transgenic plants that lacked LOX2. Thus, LOX2 is required for the wound-induced synthesis of the plant growth regulator JA in leaves. We also examined the expression of a wound- and JA-inducible Arabidopsis gene, vsp, in transgenic and control plants. Leaves of transgenic plants lacking LOX2 accumulated less vsp mRNA than did control leaves in response to wounding. This result suggests that wound-induced JA (or some other LOX2-requiring component of the wound response pathway) is involved in the wound-induced regulation of this gene.

  11. Arabidopsis Flower and Embryo Developmental Genes are Repressed in Seedlings by Different Combinations of Polycomb Group Proteins in Association with Distinct Sets of Cis-regulatory Elements.

    Science.gov (United States)

    Wang, Hua; Liu, Chunmei; Cheng, Jingfei; Liu, Jian; Zhang, Lei; He, Chongsheng; Shen, Wen-Hui; Jin, Hong; Xu, Lin; Zhang, Yijing

    2016-01-01

    Polycomb repressive complexes (PRCs) play crucial roles in transcriptional repression and developmental regulation in both plants and animals. In plants, depletion of different members of PRCs causes both overlapping and unique phenotypic defects. However, the underlying molecular mechanism determining the target specificity and functional diversity is not sufficiently characterized. Here, we quantitatively compared changes of tri-methylation at H3K27 in Arabidopsis mutants deprived of various key PRC components. We show that CURLY LEAF (CLF), a major catalytic subunit of PRC2, coordinates with different members of PRC1 in suppression of distinct plant developmental programs. We found that expression of flower development genes is repressed in seedlings preferentially via non-redundant role of CLF, which specifically associated with LIKE HETEROCHROMATIN PROTEIN1 (LHP1). In contrast, expression of embryo development genes is repressed by PRC1-catalytic core subunits AtBMI1 and AtRING1 in common with PRC2-catalytic enzymes CLF or SWINGER (SWN). This context-dependent role of CLF corresponds well with the change in H3K27me3 profiles, and is remarkably associated with differential co-occupancy of binding motifs of transcription factors (TFs), including MADS box and ABA-related factors. We propose that different combinations of PRC members distinctively regulate different developmental programs, and their target specificity is modulated by specific TFs.

  12. Arabidopsis Flower and Embryo Developmental Genes are Repressed in Seedlings by Different Combinations of Polycomb Group Proteins in Association with Distinct Sets of Cis-regulatory Elements.

    Directory of Open Access Journals (Sweden)

    Hua Wang

    2016-01-01

    Full Text Available Polycomb repressive complexes (PRCs play crucial roles in transcriptional repression and developmental regulation in both plants and animals. In plants, depletion of different members of PRCs causes both overlapping and unique phenotypic defects. However, the underlying molecular mechanism determining the target specificity and functional diversity is not sufficiently characterized. Here, we quantitatively compared changes of tri-methylation at H3K27 in Arabidopsis mutants deprived of various key PRC components. We show that CURLY LEAF (CLF, a major catalytic subunit of PRC2, coordinates with different members of PRC1 in suppression of distinct plant developmental programs. We found that expression of flower development genes is repressed in seedlings preferentially via non-redundant role of CLF, which specifically associated with LIKE HETEROCHROMATIN PROTEIN1 (LHP1. In contrast, expression of embryo development genes is repressed by PRC1-catalytic core subunits AtBMI1 and AtRING1 in common with PRC2-catalytic enzymes CLF or SWINGER (SWN. This context-dependent role of CLF corresponds well with the change in H3K27me3 profiles, and is remarkably associated with differential co-occupancy of binding motifs of transcription factors (TFs, including MADS box and ABA-related factors. We propose that different combinations of PRC members distinctively regulate different developmental programs, and their target specificity is modulated by specific TFs.

  13. A distant coilin homologue is required for the formation of cajal bodies in Arabidopsis.

    Science.gov (United States)

    Collier, Sarah; Pendle, Alison; Boudonck, Kurt; van Rij, Tjeerd; Dolan, Liam; Shaw, Peter

    2006-07-01

    Cajal bodies (CBs) are subnuclear bodies that are widespread in eukaryotes, being found in mammals, many other vertebrates and in all plant species so far examined. They are mobile structures, moving, fusing, and budding within the nucleus. Here we describe a screen for Arabidopsis mutants with altered CBs and describe mutants that have smaller Cajal bodies (ncb-2, ncb-3), lack them altogether (ncb-1), have increased numbers of CBs (pcb) or have flattened CBs (ccb). We have identified the gene affected in the ncb mutants as a distant homolog of the vertebrate gene that encodes coilin (At1g13030) and have termed the resulting protein Atcoilin. A T-DNA insertional mutant in this gene (ncb-4) also lacks Cajal bodies. Overexpression of Atcoilin cDNA in ncb-1 restores Cajal bodies, which recruit U2B'' as in the wild type, but which are, however, much larger than in the wild type. Thus we have shown that At1g13030 is required for Cajal body formation in Arabidopsis, and we hypothesize that the level of its expression is correlated with Cajal body size. The Atcoilin gene is unaffected in pcb and ccb, suggesting that other genes can also affect CBs.

  14. 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.

  15. The BIG gene is required for auxin-mediated organ growth in Arabidopsis.

    Science.gov (United States)

    Guo, Xiaola; Lu, Wenwen; Ma, Yurong; Qin, Qianqian; Hou, Suiwen

    2013-04-01

    Control of organ size by cell expansion and cell proliferation is a fundamental process during development, but the importance of BIG in this process is still poorly understood. Here, we report the isolation and characterization of a new allele mutant of BIG in Arabidopsis: big-j588. The mutant displayed small aerial organs that were characterized by reduced cell size in the epidermis and short roots with decreased cell numbers. The big-j588 axr1 double and big-j588 arf7 arf19 triple mutants displayed more severe defects in leaf expansion and root elongation than their parents, implying BIG is involved in auxin-dependent organ growth. Genetic analysis suggests that BIG may act synergistically with PIN1 to affect leaf growth. The PIN1 protein level decreased in both the root cells and the tips of leaf pavement cell lobes of big-j588. Further analysis showed that the auxin maxima in the roots and the leaves of big-j588 decreased. Therefore, we concluded that the small leaves and the short roots of big-j588 were associated with reduction of auxin maxima. Overall, our study suggested that BIG is required for Arabidopsis organ growth via auxin action.

  16. Cyclin D and cdk4 Are Required for Normal Development beyond the Blastula Stage in Sea Urchin Embryos

    Science.gov (United States)

    Moore, Jennifer C.; Sumerel, Jan L.; Schnackenberg, Bradley J.; Nichols, Jason A.; Wikramanayake, Athula; Wessel, Gary M.; Marzluff, William F.

    2002-01-01

    cdk4 mRNA and protein are constitutively expressed in sea urchin eggs and throughout embryonic development. In contrast, cyclin D mRNA is barely detectable in eggs and early embryos, when the cell cycles consist of alternating S and M phases. Cyclin D mRNA increases dramatically in embryos at the early blastula stage and remains at a constant level throughout embryogenesis. An increase in cdk4 kinase activity occurs concomitantly with the increase in cyclin D mRNA. Ectopic expression of cyclin D mRNA in eggs arrests development before the 16-cell stage and causes eventual embryonic death, suggesting that activation of cyclin D/cdk4 in cleavage cell cycles is lethal to the embryo. In contrast, blocking cyclin D or cdk4 expression with morpholino antisense oligonucleotides results in normal development of early gastrula-stage embryos but abnormal, asymmetric larvae. These results suggest that in sea urchins, cyclin D and cdk4 are required for normal development and perhaps the patterning of the developing embryo, but may not be directly involved in regulating entry into the cell cycle. PMID:12052892

  17. Nucleoporins Nup160 and Seh1 are required for disease resistance in Arabidopsis.

    Science.gov (United States)

    Roth, Charlotte; Wiermer, Marcel

    2012-10-01

    Arabidopsis Nup160 and Seh1, encoding two predicted nucleoporins of the Nup107-160 nuclear pore sub-complex, were identified in a reverse genetics screen based on their requirement for basal disease resistance. Both genes also contribute to immunity conferred by Toll interleukin 1 receptor/nucleotide-binding/leucine-rich repeat (TNL)-type R proteins and constitutive resistance activated in the deregulated TNL mutant, snc1. Protein amounts of EDS1, a central regulator of TNL-triggered resistance, are reduced in seh1 and severely depleted in nup160 single mutants. Here, we investigate the impact of mutations in Nup160, Seh1 and a third complex member, MOS3/Nup96, on EDS1 protein accumulation in the snc1 auto-immune mutant background. In addition, we examine the subcellular localization of Seh1 in root tissues.

  18. An Arabidopsis thaliana high-affinity molybdate transporter required for efficient uptake of molybdate from soil.

    Science.gov (United States)

    Tomatsu, Hajime; Takano, Junpei; Takahashi, Hideki; Watanabe-Takahashi, Akiko; Shibagaki, Nakako; Fujiwara, Toru

    2007-11-20

    Molybdenum (Mo) is a trace element essential for living organisms, however no molybdate transporter has been identified in eukaryotes. Here, we report the identification of a molybdate transporter, MOT1, from Arabidopsis thaliana. MOT1 is expressed in both roots and shoots, and the MOT1 protein is localized, in part, to plasma membranes and to vesicles. MOT1 is required for efficient uptake and translocation of molybdate and for normal growth under conditions of limited molybdate supply. Kinetics studies in yeast revealed that the K(m) value of MOT1 for molybdate is approximately 20 nM. Furthermore, Mo uptake by MOT1 in yeast was not affected by coexistent sulfate, and MOT1 did not complement a sulfate transporter-deficient yeast mutant strain. These data confirmed that MOT1 is specific for molybdate and that the high affinity of MOT1 allows plants to obtain scarce Mo from soil.

  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

    2016-07-06

    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.

  20. DNA methyltransferases are required to induce heterochromatic re-replication in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Hume Stroud

    2012-07-01

    Full Text Available The relationship between epigenetic marks on chromatin and the regulation of DNA replication is poorly understood. Mutations of the H3K27 methyltransferase genes, Arabidopsis trithorax-related protein5 (ATXR5 and ATXR6, result in re-replication (repeated origin firing within the same cell cycle. Here we show that mutations that reduce DNA methylation act to suppress the re-replication phenotype of atxr5 atxr6 mutants. This suggests that DNA methylation, a mark enriched at the same heterochromatic regions that re-replicate in atxr5/6 mutants, is required for aberrant re-replication. In contrast, RNA sequencing analyses suggest that ATXR5/6 and DNA methylation cooperatively transcriptionally silence transposable elements (TEs. Hence our results suggest a complex relationship between ATXR5/6 and DNA methylation in the regulation of DNA replication and transcription of TEs.

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

    DEFF Research Database (Denmark)

    Rautengarten, Carsten; Ebert, Berit; Liu, Lifeng

    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....

  2. 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.

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

    Science.gov (United States)

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

    2007-01-16

    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 C(3)HC(4) 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 dysfunctional RING finger were created in an Arabidopsis WT background (DeltaZn plants). They could be normalized by growth in an atmosphere of high CO(2) partial pressure, indicating a defect in photorespiration. beta-Oxidation in mutant glyoxysomes was not affected. However, an abnormal accumulation of the photorespiratory metabolite glyoxylate, a lowered content of carotenoids and chlorophyll a and b, and a decreased quantum yield of photosystem II were detected under normal atmosphere, suggesting impaired leaf peroxisomes. Light and transmission electron microscopy demonstrated leaf peroxisomes of the DeltaZn plants to be more numerous, multilobed, clustered, and not appressed to the chloroplast envelope as in WT. We suggest that inactivation of the RING finger domain in PEX10 has eliminated protein interaction required for attachment of peroxisomes to chloroplasts and movement of metabolites between peroxisomes and chloroplasts.

  4. 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.

  5. The conserved endoribonuclease YbeY is required for chloroplast ribosomal RNA processing in Arabidopsis.

    Science.gov (United States)

    Liu, Jinwen; Zhou, Wenbin; Liu, Guifeng; Yang, Chuanping; Sun, Yi; Wu, Wenjuan; Cao, Shenquan; Wang, Chong; Hai, Guanghui; Wang, Zhifeng; Bock, Ralph; Huang, Jirong; Cheng, Yuxiang

    2015-05-01

    Maturation of chloroplast ribosomal RNAs (rRNAs) comprises several endoribonucleolytic and exoribonucleolytic processing steps. However, little is known about the specific enzymes involved and the cleavage steps they catalyze. Here, we report the functional characterization of the single Arabidopsis (Arabidopsis thaliana) gene encoding a putative YbeY endoribonuclease. AtYbeY null mutants are seedling lethal, indicating that AtYbeY function is essential for plant growth. Knockdown plants display slow growth and show pale-green leaves. Physiological and ultrastructural analyses of atybeY mutants revealed impaired photosynthesis and defective chloroplast development. Fluorescent microcopy analysis showed that, when fused with the green fluorescence protein, AtYbeY is localized in chloroplasts. Immunoblot and RNA gel-blot assays revealed that the levels of chloroplast-encoded subunits of photosynthetic complexes are reduced in atybeY mutants, but the corresponding transcripts accumulate normally. In addition, atybeY mutants display defective maturation of both the 5' and 3' ends of 16S, 23S, and 4.5S rRNAs as well as decreased accumulation of mature transcripts from the transfer RNA genes contained in the chloroplast rRNA operon. Consequently, mutant plants show a severe deficiency in ribosome biogenesis, which, in turn, results in impaired plastid translational activity. Furthermore, biochemical assays show that recombinant AtYbeY is able to cleave chloroplast rRNAs as well as messenger RNAs and transfer RNAs in vitro. Taken together, our findings indicate that AtYbeY is a chloroplast-localized endoribonuclease that is required for chloroplast rRNA processing and thus for normal growth and development.

  6. Sulfation of fucoidin in Fucus embryos. III. Required for localization in the rhizoid wall.

    Science.gov (United States)

    Hogsett, W E; Quatrano, R S

    1978-09-01

    Zygotes of the brown alga Fucus distichus L. Powell accumulate a sulfated polysaccharide (fucoidin) in the cell wall at the site of rhizoid formation. Previous work indicated that zygotes grown in seawater minus sulfate do not sulfate the preformed fucan (an unsulfated fucoidin) but form rhizoids. Under these conditions, we determined whether sulfation of the fucan is required for its localization in the rhizoid wall. This was accomplished by developing a specific stain for both the fucan and fucoidin. Using a precipitin assay, we demonstrated in vitro that the lectin ricin (RCA(I)) specifically complexes with both the sulfated and desulfated polysaccharide. No precipitate is observed when either is incubated in 0.1 M D-galactose or when RCA(I) is mixed with laminarin or alginic acid, the other major polysaccharides in Fucus. RCA(I) conjugated with fluorescein isothiocyanate (FITC) is also shown to bind specifically to fucoidin using a filter paper (DE81) assay. When added to zygotes, RCA(I)-FITC binds only to the site of fucoidin localization, i.e., the rhizoid cell wall. However, RCA(I)-FITC is not observed in the rhizoid wall of zygotes grown in the absence of sulfate. This observation is not due to inability of RCA(I)-FITC to bind to the fucan in vivo. Chemically desulfated cell walls that contained fucoidin in the rhizoid wall bind RCA(I)-FITC only in the rhizoid region. Also, the concentration of fucose-containing polymers and polysaccharides that form precipitates with RCA(I) is the same in embryos grown in the presence or absence of sulfate. If sulfate is added back to cultures of zygotes grown without sulfate, fucoidin is detected at the rhizoid tip by RCA(I)-FITC several hours later. These results support the conclusion that the enzymatic sulfation of the fucan is a modification of the polysaccharide required for its localization and/or assembly into a specific region of the cell wall.

  7. Myomaker is required for the fusion of fast-twitch myocytes in the zebrafish embryo.

    Science.gov (United States)

    Zhang, Weibin; Roy, Sudipto

    2017-03-01

    During skeletal muscle development, myocytes aggregate and fuse to form multinucleated muscle fibers. Inhibition of myocyte fusion is thought to significantly derail the differentiation of functional muscle fibers. Despite the purported importance of fusion in myogenesis, in vivo studies of this process in vertebrates are rather limited. Myomaker, a multipass transmembrane protein, has been shown to be the first muscle-specific fusion protein essential for myocyte fusion in the mouse. We have generated loss-of-function alleles in zebrafish myomaker, and found that fusion of myocytes into syncytial fast-twitch muscles was significantly compromised. However, mutant myocytes could be recruited to fuse with wild-type myocytes in chimeric embryos, albeit rather inefficiently. Conversely, overexpression of Myomaker was sufficient to induce hyperfusion among fast-twitch myocytes, and it also induced fusion among slow-twitch myocytes that are normally fusion-incompetent. In line with this, Myomaker overexpression also triggered fusion in another myocyte fusion mutant compromised in the function of the junctional cell adhesion molecule, Jam2a. We also provide evidence that Rac, a regulator of actin cytoskeleton, requires Myomaker activity to induce fusion, and that an approximately 3kb of myomaker promoter sequence, with multiple E-box motifs, is sufficient to direct expression within the fast-twitch muscle lineage. Taken together, our findings underscore a conserved role for Myomaker in vertebrate myocyte fusion. Strikingly, and in contrast to the mouse, homozygous myomaker mutants are viable and do not exhibit discernible locomotory defects. Thus, in the zebrafish, myocyte fusion is not an absolute requirement for skeletal muscle morphogenesis and function.

  8. Sucrose-specific induction of anthocyanin biosynthesis in Arabidopsis requires the MYB75/PAP1 gene.

    NARCIS (Netherlands)

    Teng, S.; Keurentjes, J.J.B.; Bentsink, L.; Koornneef, M.; Smeekens, S.

    2005-01-01

    Sugar-induced anthocyanin accumulation has been observed in many plant species. We observed that sucrose (Suc) is the most effective inducer of anthocyanin biosynthesis in Arabidopsis (Arabidopsis thaliana) seedlings. Other sugars and osmotic controls are either less effective or ineffective. Analys

  9. 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.

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

    Science.gov (United States)

    De Giorgi, Julien; Piskurewicz, Urszula; Loubery, Sylvain; Utz-Pugin, Anne; Bailly, Christophe; Mène-Saffrané, Laurent; Lopez-Molina, Luis

    2015-12-01

    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.

  11. 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.

  12. 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.

  13. Steroids are required for epidermal cell fate establishment in Arabidopsis roots.

    Science.gov (United States)

    Kuppusamy, Kavitha T; Chen, Andrew Y; Nemhauser, Jennifer L

    2009-05-12

    The simple structure of Arabidopsis roots provides an excellent model system to study epidermal cell fate specification. Epidermal cells in contact with 2 underlying cortical cells differentiate into hair cells (H cells; trichoblasts), whereas cells that contact only a single cortical cell differentiate into mature hairless cells (N cells; atrichoblasts). This position-dependent patterning, in combination with the constrained orientation of cell divisions, results in hair and nonhair cell files running longitudinally along the root epidermis. Here, we present strong evidence that steroid hormones called brassinosteroids (BRs) are required to maintain position-dependent fate specification in roots. We show that BRs are required for normal expression levels and patterns of WEREWOLF (WER) and GLABRA2 (GL2), master regulators of epidermal patterning. Loss of BR signaling results in loss of hair cells in H positions, likely as a consequence of reduced expression of CAPRICE (CPC), a direct downstream target of WER. Our observations demonstrate that in addition to their well-known role in cell expansion, BRs play an essential role in directing cell fate.

  14. 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.

  15. 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.

  16. 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

    @@ The corresponding author is sorry for the following errors. 1. The first sentence of the Results section is corrected to read: The albino mutant (SALK_016097) was obtained from Arabidopsis Biological Resource Center (ABRC).

  17. D6PK AGCVIII kinases are required for auxin transport and phototropic hypocotyl bending in Arabidopsis.

    Science.gov (United States)

    Willige, Björn C; Ahlers, Siv; Zourelidou, Melina; Barbosa, Inês C R; Demarsy, Emilie; Trevisan, Martine; Davis, Philip A; Roelfsema, M Rob G; Hangarter, Roger; Fankhauser, Christian; Schwechheimer, Claus

    2013-05-01

    Phototropic hypocotyl bending in response to blue light excitation is an important adaptive process that helps plants to optimize their exposure to light. In Arabidopsis thaliana, phototropic hypocotyl bending is initiated by the blue light receptors and protein kinases phototropin1 (phot1) and phot2. Phototropic responses also require auxin transport and were shown to be partially compromised in mutants of the PIN-FORMED (PIN) auxin efflux facilitators. We previously described the D6 PROTEIN KINASE (D6PK) subfamily of AGCVIII kinases, which we proposed to directly regulate PIN-mediated auxin transport. Here, we show that phototropic hypocotyl bending is strongly dependent on the activity of D6PKs and the PIN proteins PIN3, PIN4, and PIN7. While early blue light and phot-dependent signaling events are not affected by the loss of D6PKs, we detect a gradual loss of PIN3 phosphorylation in d6pk mutants of increasing complexity that is most severe in the d6pk d6pkl1 d6pkl2 d6pkl3 quadruple mutant. This is accompanied by a reduction of basipetal auxin transport in the hypocotyls of d6pk as well as in pin mutants. Based on our data, we propose that D6PK-dependent PIN regulation promotes auxin transport and that auxin transport in the hypocotyl is a prerequisite for phot1-dependent hypocotyl bending.

  18. Karrikins discovered in smoke trigger Arabidopsis seed germination by a mechanism requiring gibberellic acid synthesis and light.

    Science.gov (United States)

    Nelson, David C; Riseborough, Julie-Anne; Flematti, Gavin R; Stevens, Jason; Ghisalberti, Emilio L; Dixon, Kingsley W; Smith, Steven M

    2009-02-01

    Discovery of the primary seed germination stimulant in smoke, 3-methyl-2H-furo[2,3-c]pyran-2-one (KAR1), has resulted in identification of a family of structurally related plant growth regulators, karrikins. KAR1 acts as a key germination trigger for many species from fire-prone, Mediterranean climates, but a molecular mechanism for this response remains unknown. We demonstrate that Arabidopsis (Arabidopsis thaliana), an ephemeral of the temperate northern hemisphere that has never, to our knowledge, been reported to be responsive to fire or smoke, rapidly and sensitively perceives karrikins. Thus, these signaling molecules may have greater significance among angiosperms than previously realized. Karrikins can trigger germination of primary dormant Arabidopsis seeds far more effectively than known phytohormones or the structurally related strigolactone GR-24. Natural variation and depth of seed dormancy affect the degree of KAR1 stimulation. Analysis of phytohormone mutant germination reveals suppression of KAR1 responses by abscisic acid and a requirement for gibberellin (GA) synthesis. The reduced germination of sleepy1 mutants is partially recovered by KAR1, which suggests that germination enhancement by karrikin is only partly DELLA dependent. While KAR1 has little effect on sensitivity to exogenous GA, it enhances expression of the GA biosynthetic genes GA3ox1 and GA3ox2 during seed imbibition. Neither abscisic acid nor GA levels in seed are appreciably affected by KAR1 treatment prior to radicle emergence, despite marked differences in germination outcome. KAR1 stimulation of Arabidopsis germination is light-dependent and reversible by far-red exposure, although limited induction of GA3ox1 still occurs in the dark. The observed requirements for light and GA biosynthesis provide the first insights into the karrikin mode of action.

  19. Programmed cell death activated by Rose Bengal in Arabidopsis thaliana cell suspension cultures requires functional chloroplasts.

    Science.gov (United States)

    Gutiérrez, Jorge; González-Pérez, Sergio; García-García, Francisco; Daly, Cara T; Lorenzo, Oscar; Revuelta, José L; McCabe, Paul F; Arellano, Juan B

    2014-07-01

    Light-grown Arabidopsis thaliana cell suspension culture (ACSC) were subjected to mild photooxidative damage with Rose Bengal (RB) with the aim of gaining a better understanding of singlet oxygen-mediated defence responses in plants. Additionally, ACSC were treated with H2O2 at concentrations that induced comparable levels of protein oxidation damage. Under low to medium light conditions, both RB and H2O2 treatments activated transcriptional defence responses and inhibited photosynthetic activity, but they differed in that programmed cell death (PCD) was only observed in cells treated with RB. When dark-grown ACSC were subjected to RB in the light, PCD was suppressed, indicating that the singlet oxygen-mediated signalling pathway in ACSC requires functional chloroplasts. Analysis of up-regulated transcripts in light-grown ACSC, treated with RB in the light, showed that both singlet oxygen-responsive transcripts and transcripts with a key role in hormone-activated PCD (i.e. ethylene and jasmonic acid) were present. A co-regulation analysis proved that ACSC treated with RB exhibited higher correlation with the conditional fluorescence (flu) mutant than with other singlet oxygen-producing mutants or wild-type plants subjected to high light. However, there was no evidence for the up-regulation of EDS1, suggesting that activation of PCD was not associated with the EXECUTER- and EDS1-dependent signalling pathway described in the flu mutant. Indigo Carmine and Methylene Violet, two photosensitizers unable to enter chloroplasts, did not activate transcriptional defence responses in ACSC; however, whether this was due to their location or to their inherently low singlet oxygen quantum efficiencies was not determined.

  20. Nucleoporin MOS7/Nup88 is required for mitosis in gametogenesis and seed development in Arabidopsis.

    Science.gov (United States)

    Park, Guen Tae; Frost, Jennifer M; Park, Jin-Sup; Kim, Tae Ho; Lee, Jong Seob; Oh, Sung Aeong; Twell, David; Brooks, Janie Sue; Fischer, Robert L; Choi, Yeonhee

    2014-12-23

    Angiosperm reproduction is characterized by alternate diploid sporophytic and haploid gametophytic generations. Gametogenesis shares similarities with that of animals except for the formation of the gametophyte, whereby haploid cells undergo several rounds of postmeiotic mitosis to form gametes and the accessory cells required for successful reproduction. The mechanisms regulating gametophyte development in angiosperms are incompletely understood. Here, we show that the nucleoporin Nup88-homolog MOS7 (Modifier of Snc1,7) plays a crucial role in mitosis during both male and female gametophyte formation in Arabidopsis thaliana. Using a mutagenesis screen, we identify the mos7-5 mutant allele, which causes ovule and pollen abortion in MOS7/mos7-5 heterozygous plants, and preglobular stage embryonic lethality in homozygous mos7-5 seeds. During interphase, we show that MOS7 is localized to the nuclear membrane but, like many nucleoporins, is associated with the spindle apparatus during mitosis. We detect interactions between MOS7 and several nucleoporins known to control spindle dynamics, and find that in pollen from MOS7/mos7-5 heterozygotes, abortion is accompanied by a failure of spindle formation, cell fate specification, and phragmoplast activity. Most intriguingly, we show that following gamete formation by MOS7/mos7-5 heterozygous spores, inheritance of either the MOS7 or the mos7-5 allele by a given gamete does not correlate with its respective survival or abortion. Instead, we suggest a model whereby MOS7, which is highly expressed in the Pollen- and Megaspore Mother Cells, enacts a dosage-limiting effect on the gametes to enable their progression through subsequent mitoses.

  1. Arabidopsis plastidial folylpolyglutamate synthetase is required for seed reserve accumulation and seedling establishment in darkness.

    Directory of Open Access Journals (Sweden)

    Hongyan Meng

    Full Text Available Interactions among metabolic pathways are important in plant biology. At present, not much is known about how folate metabolism affects other metabolic pathways in plants. Here we report a T-DNA insertion mutant (atdfb-3 of the plastidial folylpolyglutamate synthetase gene (AtDFB was defective in seed reserves and skotomorphogenesis. Lower carbon (C and higher nitrogen (N content in the mutant seeds than that of the wild type were indicative of an altered C and N partitioning capacity. Higher levels of organic acids and sugars were detected in the mutant seeds compared with the wild type. Further analysis revealed that atdfb-3 seeds contained less total amino acids and individual Asn and Glu as well as NO3-. These results indicate significant changes in seed storage in the mutant. Defects in hypocotyl elongation were observed in atdfb-3 in darkness under sufficient NO3- conditions, and further enhanced under NO3- limited conditions. The strong expression of AtDFB in cotyledons and hypocotyl during early developmental stage was consistent with the mutant sensitivity to limited NO3- during a narrow developmental window. Exogenous 5-formyl-tetrahydrofolate completely restored the hypocotyl length in atdfb-3 seedlings with NO3- as the sole N source. Further study demonstrated that folate profiling and N metabolism were perturbed in atdfb-3 etiolated seedlings. The activity of enzymes involved in N reduction and assimilation was altered in atdfb-3. Taken together, these results indicate that AtDFB is required for seed reserves, hypocotyl elongation and N metabolism in darkness, providing novel insights into potential associations of folate metabolism with seed reserve accumulation, N metabolism and hypocotyl development in Arabidopsis.

  2. 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.

  3. The Arabidopsis thaliana DSB formation (AtDFO) gene is required for meiotic double-strand break formation.

    Science.gov (United States)

    Zhang, Cheng; Song, Yao; Cheng, Zhi-hao; Wang, Ying-xiang; Zhu, Jun; Ma, Hong; Xu, Ling; Yang, Zhong-Nan

    2012-10-01

    DNA double-strand break (DSB) formation is the initial event for meiotic recombination catalyzed by the conserved Spo11 protein. In Arabidopsis, several proteins have been reported to be involved in DSB formation. Here, we report an Arabidopsis DSB forming (DFO) gene in Arabidopsis that is involved in DSB formation. The dfo mutant exhibits reduced fertility, producing polyads with an abnormal number of microspores, unlike the tetrads in the wild type. The dfo meiocytes were defective in homologous chromosome synapsis and segregation. Genetic analysis revealed that the homologous recombination of Atdfo-1 is severely affected in meiotic prophase I. DFO encodes a protein without any known conserved domain. There was no homologue identified outside the plant kingdom, indicating that AtDFO is a plant-specific protein. AtMRE11 has been reported to be responsible for processing SPO11-generated DSBs. The Atmre11 mutant displays chromosome fragmentation during meiosis. However, the Atdfo Atmre11 double mutant had no such chromosome fragmentation, indicating that AtDFO is required for DSB formation.

  4. The SLO1 PPR protein is required for RNA editing at multiple sites with similar upstream sequences in Arabidopsis mitochondria.

    Science.gov (United States)

    Sung, Tzu-Ying; Tseng, Ching-Chih; Hsieh, Ming-Hsiun

    2010-08-01

    In Arabidopsis, RNA editing changes more than 500 cytidines to uridines in mitochondrial transcripts. The editing enzyme and co-factors involved in these processes are largely unknown. We have identified a nuclear gene SLOW GROWTH1 (SLO1) encoding an E motif-containing pentatricopeptide repeat protein that is required for RNA editing of nad4 and nad9 in Arabidopsis mitochondria. The SLO1 protein is localized to the mitochondrion, and its absence gives rise to small plants with slow growth and delayed development. A survey of approximately 500 mitochondrial RNA editing sites in Arabidopsis reveals that the editing of two sites, nad4-449 and nad9-328, is abolished in the slo1 mutants. Sequence comparison in the upstream (from -1 to -15 bp) of nad4-449 and nad9-328 editing sites shows that nine of the 15 nucleotides are identical. In addition to RNA editing, we used RNA gel blot analysis to compare the abundance and banding patterns of mitochondrial transcripts between the wild type and slo1 mutants. Of the 79 genes and open reading frames examined, steady-state levels of 56 mitochondrial transcripts are increased in the slo1 mutants. These results suggest that the SLO1 protein may indirectly regulate plant growth and development via affecting mitochondrial RNA editing and gene expression.

  5. Basipetal auxin transport is required for gravitropism in roots of Arabidopsis

    Science.gov (United States)

    Rashotte, A. M.; Brady, S. R.; Reed, R. C.; Ante, S. J.; Muday, G. K.; Davies, E. (Principal Investigator)

    2000-01-01

    Auxin transport has been reported to occur in two distinct polarities, acropetally and basipetally, in two different root tissues. The goals of this study were to determine whether both polarities of indole-3-acetic acid (IAA) transport occur in roots of Arabidopsis and to determine which polarity controls the gravity response. Global application of the auxin transport inhibitor naphthylphthalamic acid (NPA) to roots blocked the gravity response, root waving, and root elongation. Immediately after the application of NPA, the root gravity response was completely blocked, as measured by an automated video digitizer. Basipetal [(3)H]IAA transport in Arabidopsis roots was inhibited by NPA, whereas the movement of [(14)C]benzoic acid was not affected. Inhibition of basipetal IAA transport by local application of NPA blocked the gravity response. Inhibition of acropetal IAA transport by application of NPA at the root-shoot junction only partially reduced the gravity response at high NPA concentrations. Excised root tips, which do not receive auxin from the shoot, exhibited a normal response to gravity. The Arabidopsis mutant eir1, which has agravitropic roots, exhibited reduced basipetal IAA transport but wild-type levels of acropetal IAA transport. These results support the hypothesis that basipetally transported IAA controls root gravitropism in Arabidopsis.

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

    Science.gov (United States)

    Tran, Martin; Tsarouhas, Vasilios; Kegel, Andreas

    2016-07-15

    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.

  7. 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.

  8. High environmental temperature increases glucose requirement in the developing chicken embryo.

    Directory of Open Access Journals (Sweden)

    Roos Molenaar

    Full Text Available Environmental conditions during the perinatal period influence metabolic and developmental processes in mammals and avian species, which could impact pre- and postnatal survival and development. The current study investigated the effect of eggshell temperature (EST on glucose metabolism in broiler chicken embryos. Broiler eggs were incubated at a high (38.9°C or normal (37.8°C EST from day 10.5 of incubation onward and were injected with a bolus of [U-(13C]glucose in the chorio-allantoic fluid at day 17.5 of incubation. After [U-(13C]glucose administration, (13C enrichment was determined in intermediate pools and end-products of glucose metabolism. Oxidation of labeled glucose occurred for approximately 3 days after injection. Glucose oxidation was higher in the high than in the normal EST treatment from day 17.6 until 17.8 of incubation. The overall recovery of (13CO2 tended to be 4.7% higher in the high than in the normal EST treatment. An increase in EST (38.9°C vs 37.8°C increased (13C enrichment in plasma lactate at day 17.8 of incubation and (13C in hepatic glycogen at day 18.8 of incubation. Furthermore, high compared to normal EST resulted in a lower yolk-free body mass at day 20.9 (-2.74 g and 21.7 (-3.81 g of incubation, a lower hepatic glycogen concentration at day 18.2 (-4.37 mg/g and 18.8 (-4.59 mg/g of incubation, and a higher plasma uric acid concentration (+2.8 mg/mL/+43% at day 21.6 of incubation. These results indicate that the glucose oxidation pattern is relatively slow, but the intensity increased consistently with an increase in developmental stage of the embryo. High environmental temperatures in the perinatal period of chicken embryos increased glucose oxidation and decreased hepatic glycogen prior to the hatching process. This may limit glucose availability for successful hatching and could impact body development, probably by increased gluconeogenesis from glucogenic amino acids to allow anaerobic glycolysis.

  9. Arabidopsis phosphoglycerate dehydrogenase1 of the phosphoserine pathway is essential for development and required for ammonium assimilation and tryptophan biosynthesis.

    Science.gov (United States)

    Benstein, Ruben Maximilian; Ludewig, Katja; Wulfert, Sabine; Wittek, Sebastian; Gigolashvili, Tamara; Frerigmann, Henning; Gierth, Markus; Flügge, Ulf-Ingo; Krueger, Stephan

    2013-12-01

    In plants, two independent serine biosynthetic pathways, the photorespiratory and glycolytic phosphoserine (PS) pathways, have been postulated. Although the photorespiratory pathway is well characterized, little information is available on the function of the PS pathway in plants. Here, we present a detailed characterization of phosphoglycerate dehydrogenases (PGDHs) as components of the PS pathway in Arabidopsis thaliana. All PGDHs localize to plastids and possess similar kinetic properties, but they differ with respect to their sensitivity to serine feedback inhibition. Furthermore, analysis of pgdh1 and phosphoserine phosphatase mutants revealed an embryo-lethal phenotype and PGDH1-silenced lines were inhibited in growth. Metabolic analyses of PGDH1-silenced lines grown under ambient and high CO2 conditions indicate a direct link between PS biosynthesis and ammonium assimilation. In addition, we obtained several lines of evidence for an interconnection between PS and tryptophan biosynthesis, because the expression of PGDH1 and phosphoserine aminotransferase1 is regulated by MYB51 and MYB34, two activators of tryptophan biosynthesis. Moreover, the concentration of tryptophan-derived glucosinolates and auxin were reduced in PGDH1-silenced plants. In essence, our results provide evidence for a vital function of PS biosynthesis for plant development and metabolism.

  10. The importance of SERINE DECARBOXYLASE1 (SDC1) and ethanolamine biosynthesis during embryogenesis of Arabidopsis thaliana.

    Science.gov (United States)

    Yunus, Ian Sofian; Liu, Yu-Chi; Nakamura, Yuki

    2016-11-01

    In plants, ethanolamine is considered a precursor for the synthesis of choline, which is an essential dietary nutrient for animals. An enzyme serine decarboxylase (SDC) has been identified and characterized in Arabidopsis, which directly converts serine to ethanolamine, a precursor to phosphorylethanolamine and its subsequent metabolites in plants. However, the importance of SDC and ethanolamine production in plant growth and development remains unclear. Here, we show that SDC is required for ethanolamine biosynthesis in vivo and essential in plant embryogenesis in Arabidopsis. The knockout of SDC1 caused an embryonic lethal defect due to the developmental arrest of the embryos at the heart stage. During embryo development, the expression was observed at the later stages, at which developmental defect occurred in the knockout mutant. Overexpression of SDC1 in planta increased levels of ethanolamine, phosphatidylethanolamine, and phosphatidylcholine both in leaves and siliques. These results suggest that SDC1 plays an essential role in ethanolamine biosynthesis during the embryogenesis in Arabidopsis.

  11. 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.

  12. SUPERKILLER Complex Components Are Required for the RNA Exosome-Mediated Control of Cuticular Wax Biosynthesis in Arabidopsis Inflorescence Stems.

    Science.gov (United States)

    Zhao, Lifang; Kunst, Ljerka

    2016-06-01

    ECERIFERUM7 (CER7)/AtRRP45B core subunit of the exosome, the main cellular 3'-to-5' exoribonuclease, is a positive regulator of cuticular wax biosynthesis in Arabidopsis (Arabidopsis thaliana) inflorescence stems. CER7-dependent exosome activity determines stem wax load by controlling transcript levels of the wax-related gene CER3 Characterization of the second-site suppressors of the cer7 mutant revealed that small interfering RNAs (siRNAs) are direct effectors of CER3 expression. To explore the relationship between the exosome and posttranscriptional gene silencing (PTGS) in regulating CER3 transcript levels, we investigated two additional suppressor mutants, wax restorer1 (war1) and war7. We show that WAR1 and WAR7 encode Arabidopsis SUPERKILLER3 (AtSKI3) and AtSKI2, respectively, components of the SKI complex that associates with the exosome during cytoplasmic 3'-to-5' RNA degradation, and that CER7-dependent regulation of wax biosynthesis also requires participation of AtSKI8. Our study further reveals that it is the impairment of the exosome-mediated 3'-5' decay of CER3 transcript in the cer7 mutant that triggers extensive production of siRNAs and efficient PTGS of CER3. This identifies PTGS as a general mechanism for eliminating highly abundant endogenous transcripts that is activated when 3'-to-5' mRNA turnover by the exosome is disrupted. Diminished efficiency of PTGS in ski mutants compared with cer7, as evidenced by lower accumulation of CER3-related siRNAs, suggests that reduced amounts of CER3 transcript are available for siRNA synthesis, possibly because CER3 mRNA that does not interact with SKI is degraded by 5'-to-3' XRN4 exoribonuclease.

  13. Reference: 67 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available A complete knockout of AGD2 renders embryos inviable. We suggest that AGD2 synthesizes an important amino a...no acid-derived molecule important for activating defense signaling. Divergent roles in Arabidopsis thaliana

  14. The Arabidopsis thaliana vernalization response requires a polycomb-like protein complex that also includes VERNALIZATION INSENSITIVE 3.

    Science.gov (United States)

    Wood, Craig C; Robertson, Masumi; Tanner, Greg; Peacock, W James; Dennis, Elizabeth S; Helliwell, Chris A

    2006-09-26

    In Arabidopsis thaliana, the promotion of flowering by cold temperatures, vernalization, is regulated via a floral-repressive MADS box transcription factor, FLOWERING LOCUS C (FLC). Vernalization leads to the epigenetic repression of FLC expression, a process that requires the polycomb group (PcG) protein VERNALIZATION 2 (VRN2) and the plant homeodomain protein VERNALIZATION INSENSITIVE 3 (VIN3). We demonstrate that the repression of FLC by vernalization requires homologues of other Polycomb Repressive Complex 2 proteins and VRN2. We show in planta that VRN2 and VIN3 are part of a large protein complex that can include the PcG proteins FERTILIZATION INDEPENDENT ENDOSPERM, CURLY LEAF, and SWINGER. These findings suggest a single protein complex is responsible for histone deacetylation at FLC and histone methylation at FLC in vernalized plants. The abundance of the complex increases during vernalization and declines after plants are returned to higher temperatures, consistent with the complex having a role in establishing FLC repression.

  15. The Arabidopsis Thylakoid Protein PAM68 Is Required for Efficient D1 Biogenesis and Photosystem II Assembly[W

    Science.gov (United States)

    Armbruster, Ute; Zühlke, Jessica; Rengstl, Birgit; Kreller, Renate; Makarenko, Elina; Rühle, Thilo; Schünemann, Danja; Jahns, Peter; Weisshaar, Bernd; Nickelsen, Jörg; Leister, Dario

    2010-01-01

    Photosystem II (PSII) is a multiprotein complex that functions as a light-driven water:plastoquinone oxidoreductase in photosynthesis. Assembly of PSII proceeds through a number of distinct intermediate states and requires auxiliary proteins. The photosynthesis affected mutant 68 (pam68) of Arabidopsis thaliana displays drastically altered chlorophyll fluorescence and abnormally low levels of the PSII core subunits D1, D2, CP43, and CP47. We show that these phenotypes result from a specific decrease in the stability and maturation of D1. This is associated with a marked increase in the synthesis of RC (the PSII reaction center-like assembly complex) at the expense of PSII dimers and supercomplexes. PAM68 is a conserved integral membrane protein found in cyanobacterial and eukaryotic thylakoids and interacts in split-ubiquitin assays with several PSII core proteins and known PSII assembly factors. Biochemical analyses of thylakoids from Arabidopsis and Synechocystis sp PCC 6803 suggest that, during PSII assembly, PAM68 proteins associate with an early intermediate complex that might contain D1 and the assembly factor LPA1. Inactivation of cyanobacterial PAM68 destabilizes RC but does not affect larger PSII assembly complexes. Our data imply that PAM68 proteins promote early steps in PSII biogenesis in cyanobacteria and plants, but their inactivation is differently compensated for in the two classes of organisms. PMID:20923938

  16. The Arabidopsis thylakoid protein PAM68 is required for efficient D1 biogenesis and photosystem II assembly.

    Science.gov (United States)

    Armbruster, Ute; Zühlke, Jessica; Rengstl, Birgit; Kreller, Renate; Makarenko, Elina; Rühle, Thilo; Schünemann, Danja; Jahns, Peter; Weisshaar, Bernd; Nickelsen, Jörg; Leister, Dario

    2010-10-01

    Photosystem II (PSII) is a multiprotein complex that functions as a light-driven water:plastoquinone oxidoreductase in photosynthesis. Assembly of PSII proceeds through a number of distinct intermediate states and requires auxiliary proteins. The photosynthesis affected mutant 68 (pam68) of Arabidopsis thaliana displays drastically altered chlorophyll fluorescence and abnormally low levels of the PSII core subunits D1, D2, CP43, and CP47. We show that these phenotypes result from a specific decrease in the stability and maturation of D1. This is associated with a marked increase in the synthesis of RC (the PSII reaction center-like assembly complex) at the expense of PSII dimers and supercomplexes. PAM68 is a conserved integral membrane protein found in cyanobacterial and eukaryotic thylakoids and interacts in split-ubiquitin assays with several PSII core proteins and known PSII assembly factors. Biochemical analyses of thylakoids from Arabidopsis and Synechocystis sp PCC 6803 suggest that, during PSII assembly, PAM68 proteins associate with an early intermediate complex that might contain D1 and the assembly factor LPA1. Inactivation of cyanobacterial PAM68 destabilizes RC but does not affect larger PSII assembly complexes. Our data imply that PAM68 proteins promote early steps in PSII biogenesis in cyanobacteria and plants, but their inactivation is differently compensated for in the two classes of organisms.

  17. Oligogalacturonide-auxin antagonism does not require posttranscriptional gene silencing or stabilization of auxin response repressors in Arabidopsis.

    Science.gov (United States)

    Savatin, Daniel V; Ferrari, Simone; Sicilia, Francesca; De Lorenzo, Giulia

    2011-11-01

    α-1-4-Linked oligogalacturonides (OGs) derived from plant cell walls are a class of damage-associated molecular patterns and well-known elicitors of the plant immune response. Early transcript changes induced by OGs largely overlap those induced by flg22, a peptide derived from bacterial flagellin, a well-characterized microbe-associated molecular pattern, although responses diverge over time. OGs also regulate growth and development of plant cells and organs, due to an auxin-antagonistic activity. The molecular basis of this antagonism is still unknown. Here we show that, in Arabidopsis (Arabidopsis thaliana), OGs inhibit adventitious root formation induced by auxin in leaf explants as well as the expression of several auxin-responsive genes. Genetic, biochemical, and pharmacological experiments indicate that inhibition of auxin responses by OGs does not require ethylene, jasmonic acid, and salicylic acid signaling and is independent of RESPIRATORY BURST OXIDASE HOMOLOGUE D-mediated reactive oxygen species production. Free indole-3-acetic acid levels are not noticeably altered by OGs. Notably, OG- as well as flg22-auxin antagonism does not involve any of the following mechanisms: (1) stabilization of auxin-response repressors; (2) decreased levels of auxin receptor transcripts through the action of microRNAs. Our results suggest that OGs and flg22 antagonize auxin responses independently of Aux/Indole-3-Acetic Acid repressor stabilization and of posttranscriptional gene silencing.

  18. Sorbitol dehydrogenase is a cytosolic protein required for sorbitol metabolism in Arabidopsis thaliana.

    Science.gov (United States)

    Aguayo, María Francisca; Ampuero, Diego; Mandujano, Patricio; Parada, Roberto; Muñoz, Rodrigo; Gallart, Marta; Altabella, Teresa; Cabrera, Ricardo; Stange, Claudia; Handford, Michael

    2013-05-01

    Sorbitol is converted to fructose in Rosaceae species by SORBITOL DEHYDROGENASE (SDH, EC 1.1.1.14), especially in sink organs. SDH has also been found in non-Rosaceae species and here we show that the protein encoded by At5g51970 in Arabidopsis thaliana (L.) Heynh. possesses the molecular characteristics of an SDH. Using a green fluorescent protein-tagged version and anti-SDH antisera, we determined that SDH is cytosolically localized, consistent with bioinformatic predictions. We also show that SDH is widely expressed, and that SDH protein accumulates in both source and sink organs. In the presence of NAD+, recombinant SDH exhibited greatest oxidative activity with sorbitol, ribitol and xylitol as substrates; other sugar alcohols were oxidized to a lesser extent. Under standard growth conditions, three independent sdh- mutants developed as wild-type. Nevertheless, all three exhibited reduced dry weight and primary root length compared to wild-type when grown in the presence of sorbitol. Additionally, under short-day conditions, the mutants were more resistant to dehydration stress, as shown by a reduced loss of leaf water content when watering was withheld, and a greater survival rate on re-watering. This evidence suggests that limitations in the metabolism of sugar alcohols alter the growth of Arabidopsis and its response to drought.

  19. 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.

  20. Peroxisomal NADP-isocitrate dehydrogenase is required for Arabidopsis stomatal movement.

    Science.gov (United States)

    Leterrier, Marina; Barroso, Juan B; Valderrama, Raquel; Begara-Morales, Juan C; Sánchez-Calvo, Beatriz; Chaki, Mounira; Luque, Francisco; Viñegla, Benjamin; Palma, José M; Corpas, Francisco J

    2016-03-01

    Peroxisomes are subcellular organelles characterized by a simple morphological structure but have a complex biochemical machinery involved in signaling processes through molecules such as hydrogen peroxide (H2O2) and nitric oxide (NO). Nicotinamide adenine dinucleotide phosphate (NADPH) is an essential component in cell redox homeostasis, and its regeneration is critical for reductive biosynthesis and detoxification pathways. Plants have several NADPH-generating dehydrogenases, with NADP-isocitrate dehydrogenase (NADP-ICDH) being one of these enzymes. Arabidopsis contains three genes that encode for cytosolic, mitochondrial/chloroplastic, and peroxisomal NADP-ICDH isozymes although the specific function of each of these remains largely unknown. Using two T-DNA insertion lines of the peroxisomal NADP-ICDH designated as picdh-1 and picdh-2, the data show that the peroxisomal NADP-ICDH is involved in stomatal movements, suggesting that peroxisomes are a new element in the signaling network of guard cells.

  1. Arabinogalactan proteins 6 and 11 are required for stamen and pollen function in Arabidopsis.

    Science.gov (United States)

    Levitin, Bella; Richter, Dganit; Markovich, Inbal; Zik, Moriyah

    2008-11-01

    Successful male reproductive function in plants is dependent on the correct development and functioning of stamens and pollen. AGP6 and AGP11 are two homologous Arabidopsis genes encoding cell wall-associated arabinogalactan glycoproteins (AGPs). Both genes were found to be specifically expressed in stamens, pollen grains and pollen tubes, suggesting that these genes may play a role in male organ development and function. RNAi lines with reduced AGP6 and AGP11 expression were generated. These, together with lines harboring point mutations in the coding region of AGP6, were used to show that loss of function in AGP6 and AGP11 led to reduced fertility, at least partly as a result of inhibition of pollen tube growth. Our results also suggest that AGP6 and AGP11 play an additional role in the release of pollen grains from the mature anther. Thus, our study demonstrates the involvement of specific AGPs in pollen tube growth and stamen function.

  2. 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

  3. Zygotic LvBMP5-8 is required for skeletal patterning and for left-right but not dorsal-ventral specification in the sea urchin embryo.

    Science.gov (United States)

    Piacentino, Michael L; Chung, Oliver; Ramachandran, Janani; Zuch, Daniel T; Yu, Jia; Conaway, Evan A; Reyna, Arlene E; Bradham, Cynthia A

    2016-04-01

    Skeletal patterning in the sea urchin embryo requires coordinated signaling between the pattern-dictating ectoderm and the skeletogenic primary mesenchyme cells (PMCs); recent studies have begun to uncover the molecular basis for this process. Using an unbiased RNA-Seq-based screen, we have previously identified the TGF-ß superfamily ligand, LvBMP5-8, as a skeletal patterning gene in Lytechinus variegatus embryos. This result is surprising, since both BMP5-8 and BMP2/4 ligands have been implicated in sea urchin dorsal-ventral (DV) and left-right (LR) axis specification. Here, we demonstrate that zygotic LvBMP5-8 is required for normal skeletal patterning on the left side, as well as for normal PMC positioning during gastrulation. Zygotic LvBMP5-8 is required for expression of the left-side marker soxE, suggesting that LvBMP5-8 is required for left-side specification. Interestingly, we also find that LvBMP5-8 knockdown suppresses serotonergic neurogenesis on the left side. While LvBMP5-8 overexpression is sufficient to dorsalize embryos, we find that zygotic LvBMP5-8 is not required for normal DV specification or development. In addition, ectopic LvBMP5-8 does not dorsalize LvBMP2/4 morphant embryos, indicating that, in the absence of BMP2/4, BMP5-8 is insufficient to specify dorsal. Taken together, our data demonstrate that zygotic LvBMP5-8 signaling is essential for left-side specification, and for normal left-side skeletal and neural patterning, but not for DV specification. Thus, while both BMP2/4 and BMP5-8 regulate LR axis specification, BMP2/4 but not zygotic BMP5-8 regulates DV axis specification in sea urchin embryos.

  4. The Toll pathway is required in the epidermis for muscle development in the Drosophila embryo

    Science.gov (United States)

    Halfon, M. S.; Keshishian, H.

    1998-01-01

    The Toll signaling pathway functions in several Drosophila processes, including dorsal-ventral pattern formation and the immune response. Here, we demonstrate that this pathway is required in the epidermis for proper muscle development. Previously, we showed that the zygotic Toll protein is necessary for normal muscle development; in the absence of zygotic Toll, close to 50% of hemisegments have muscle patterning defects consisting of missing, duplicated and misinserted muscle fibers (Halfon, M.S., Hashimoto, C., and Keshishian, H., Dev. Biol. 169, 151-167, 1995). We have now also analyzed the requirements for easter, spatzle, tube, and pelle, all of which function in the Toll-mediated dorsal-ventral patterning pathway. We find that spatzle, tube, and pelle, but not easter, are necessary for muscle development. Mutations in these genes give a phenotype identical to that seen in Toll mutants, suggesting that elements of the same pathway used for Toll signaling in dorsal-ventral development are used during muscle development. By expressing the Toll cDNA under the control of distinct Toll enhancer elements in Toll mutant flies, we have examined the spatial requirements for Toll expression during muscle development. Expression of Toll in a subset of epidermal cells that includes the epidermal muscle attachment cells, but not Toll expression in the musculature, is necessary for proper muscle development. Our results suggest that signals received by the epidermis early during muscle development are an important part of the muscle patterning process.

  5. 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

  6. Cmv2b-AGO interaction is required for the suppression of RDR-dependent antiviral silencing in Arabidopsis

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    Yuan-Yuan Fang

    2016-08-01

    Full Text Available Using a transient plant system, it was previously found that the suppression of Cucumber mosaic virus (CMV 2b protein relies on its double-strand (ds RNA binding capacity, but it is independent of its interaction with ARGONAUTE (AGO proteins. Thus, the biological meaning of the 2b-AGO interaction in the context of virus infection remains elusive. In this study, we created infectious clones of CMV mutants that expressed the 2b functional domains of dsRNA or AGO binding and tested the effect of these CMV mutants on viral pathogenicity. We found that the mutant CMV2b(1-76 expressing the 2b dsRNA-binding domain exhibited the same virulence as wild-type CMV in infection with either wild-type Arabidopsis or rdr1/6 plants with RDR1- and RDR6-deficient mutations. However, remarkably reduced viral RNA levels and increased virus (vsiRNAs were detected in CMV2b(1-76-infected Arabidopsis in comparison to CMV infection, which demonstrated that the 2b(1-76 deleted AGO-binding domain failed to suppress the RDR1/RDR6-dependent degradation of viral RNAs. The mutant CMV2b(8-111 expressing mutant 2b, in which the N-terminal 7 amino acid (aa was deleted, exhibited slightly reduced virulence, but not viral RNA levels, in both wild-type and rdr1/6 plants, which indicated that 2b retained the AGO-binding activity acquired the counter-RDRs degradation of viral RNAs. The deletion of the N-terminal 7 aa of 2b affected virulence due to the reduced affinity for long dsRNA. The mutant CMV2b(18-111 expressing mutant 2b lacked the N-terminal 17 aa but retained its AGO-binding activity greatly reduced virulence and viral RNA level. Together with the instability of both 2b(18-111-EGFP and RFP-AGO4 proteins when co-expressed in Nicotiana benthamiana leaves, our data demonstrates that the effect of 2b-AGO interaction on counter-RDRs antiviral defense required the presence of 2b dsRNA-binding activity. Taken together, our findings demonstrate that the dsRNA-binding activity of the

  7. The Cooperative Activities of CSLD2, CSLD3, and CSLD5 Are Required for Normal Arabidopsis Development

    Institute of Scientific and Technical Information of China (English)

    Lan Yina; William G.T. Willats; Henrik Vibe Scheller; Yves Verhertbruggen; Ai Oikawa; Chithra Manisseri; Bernhard Knierim; Lina Prak; Jacob Krüger Jensen; J. Paul Knoxi; Manfred Auer

    2011-01-01

    Glycosyltransferases of the Cellulose Synthase Like D (CSLD) subfamily have been reported to be involved in tip growth and stem development in Arabidopsis.The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth.In this study,we produced double and triple knockout mutants of CSLD2,CSLD3,and CSLD5.Unlike the single mutants and the csld2/csld3 double mutant,the csld2/csld5,csld3/csld5,and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability.This demonstrates that the cooperative activities of CSLD2,CSLD3,and CSLD5 are required for normal Arabidopsis development,and that they are involved in important processes besides the specialized role in tip growth.The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development,whereas the CSLD2 and CSLD3 proteins are non-redundant.To determine the biochemical function of CSLD proteins,we used transient expression in tobacco leaves.Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors.The same activity was detected when CSLD2 and CSLD3 were co-expressed but not when they were expressed separately.With monosaccharides as exogenous acceptors,microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose.These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xvlem vessels of the csld2/csld3/csld5 mutant.

  8. The Arabidopsis DCR encoding a soluble BAHD acyltransferase is required for cutin polyester formation and seed hydration properties.

    Science.gov (United States)

    Panikashvili, David; Shi, Jian Xin; Schreiber, Lukas; Aharoni, Asaph

    2009-12-01

    The cuticle covering every plant aerial organ is largely made of cutin that consists of fatty acids, glycerol, and aromatic monomers. Despite the huge importance of the cuticle to plant development and fitness, our knowledge regarding the assembly of the cutin polymer and its integration in the complete cuticle structure is limited. Cutin composition implies the action of acyltransferase-type enzymes that mediate polymer construction through ester bond formation. Here, we show that a member of the BAHD family of acyltransferases (DEFECTIVE IN CUTICULAR RIDGES [DCR]) is required for incorporation of the most abundant monomer into the polymeric structure of the Arabidopsis (Arabidopsis thaliana) flower cutin. DCR-deficient plants display phenotypes that are typically associated with a defective cuticle, including altered epidermal cell differentiation and postgenital organ fusion. Moreover, levels of the major cutin monomer in flowers, 9(10),16-dihydroxy-hexadecanoic acid, decreased to an almost undetectable amount in the mutants. Interestingly, dcr mutants exhibit changes in the decoration of petal conical cells and mucilage extrusion in the seed coat, both phenotypes formerly not associated with cutin polymer assembly. Excessive root branching displayed by dcr mutants and the DCR expression pattern in roots pointed to the function of DCR belowground, in shaping root architecture by influencing lateral root emergence and growth. In addition, the dcr mutants were more susceptible to salinity, osmotic, and water deprivation stress conditions. Finally, the analysis of DCR protein localization suggested that cutin polymerization, possibly the oligomerization step, is partially carried out in the cytoplasmic space. Therefore, this study extends our knowledge regarding the functionality of the cuticular layer and the formation of its major constituent the polymer cutin.

  9. A forkhead gene related to HNF-3beta is required for gastrulation and axis formation in the ascidian embryo.

    Science.gov (United States)

    Olsen, C L; Jeffery, W R

    1997-09-01

    We have isolated a member of the HNF-3/forkhead gene family in ascidians as a means to determine the role of winged-helix genes in chordate development. The MocuFH1 gene, isolated from a Molgula oculata cDNA library, exhibits a forkhead DNA-binding domain most similar to zebrafish axial and rodent HNF-3beta. MocuFH1 is a single copy gene but there is at least one other related forkhead gene in the M. oculata genome. The MocuFH1 gene is expressed in the presumptive endoderm, mesenchyme and notochord cells beginning during the late cleavage stages. During gastrulation, MocuFH1 expression occurs in the prospective endoderm cells, which invaginate at the vegetal pole, and in the presumptive notochord and mesenchyme cells, which involute over the anterior and lateral lips of the blastopore, respectively. However, this gene is not expressed in the presumptive muscle cells, which involute over the posterior lip of the blastopore. MocuFH1 expression continues in the same cell lineages during neurulation and axis formation, however, during the tailbud stage, MocuFH1 is also expressed in ventral cells of the brain and spinal cord. The functional role of the MocuFH1 gene was studied using antisense oligodeoxynucleotides (ODNs), which transiently reduce MocuFH1 transcript levels during gastrulation. Embryos treated with antisense ODNs cleave normally and initiate gastrulation. However, gastrulation is incomplete, some of the endoderm and notochord cells do not enter the embryo and undergo subsequent movements, and axis formation is abnormal. In contrast, the prospective muscle cells, which do not express MocuFH1, undergo involution and later express muscle actin and acetylcholinesterase, markers of muscle cell differentiation. The results suggest that MocuFH1 is required for morphogenetic movements of the endoderm and notochord precursor cells during gastrulation and axis formation. The effects of inhibiting MocuFH1 expression on embryonic axis formation in ascidians are

  10. 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.

  11. SABRE is required for stabilization of root hair patterning in Arabidopsis thaliana.

    Science.gov (United States)

    Pietra, Stefano; Lang, Patricia; Grebe, Markus

    2015-03-01

    Patterned differentiation of distinct cell types is essential for the development of multicellular organisms. The root epidermis of Arabidopsis thaliana is composed of alternating files of root hair and non-hair cells and represents a model system for studying the control of cell-fate acquisition. Epidermal cell fate is regulated by a network of genes that translate positional information from the underlying cortical cell layer into a specific pattern of differentiated cells. While much is known about the genes of this network, new players continue to be discovered. Here we show that the SABRE (SAB) gene, known to mediate microtubule organization, anisotropic cell growth and planar polarity, has an effect on root epidermal hair cell patterning. Loss of SAB function results in ectopic root hair formation and destabilizes the expression of cell fate and differentiation markers in the root epidermis, including expression of the WEREWOLF (WER) and GLABRA2 (GL2) genes. Double mutant analysis reveal that wer and caprice (cpc) mutants, defective in core components of the epidermal patterning pathway, genetically interact with sab. This suggests that SAB may act on epidermal patterning upstream of WER and CPC. Hence, we provide evidence for a role of SAB in root epidermal patterning by affecting cell-fate stabilization. Our work opens the door for future studies addressing SAB-dependent functions of the cytoskeleton during root epidermal patterning.

  12. Polycomb-group histone methyltransferase CLF is required for proper somatic recombination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Na Chen; Wang-Bin Zhou; Ying-Xiang Wang; Ai-Wu Dong; Yu Yu

    2014-01-01

    Homologous recombination (HR) is a key process during meiosis in reproductive cells and the DNA damage repair process in somatic cells. Although chromatin structure is thought to be crucial for HR, only a smal number of chromatin modifiers have been studied in HR regulation so far. Here, we investigated the function of CURLY LEAF (CLF), a Polycomb-group (PcG) gene responsible for histone3 lysine 27 trimethy-lation (H3K27me3), in somatic and meiotic HR in Arabidopsis thaliana. Although fluorescent protein reporter assays in pol en and seeds showed that the frequency of meiotic cross-over in the loss-of-function mutant clf-29 was not significantly different from that in wild type, there was a lower frequency of HR in clf-29 than in wild type under normal conditions and under bleomycin treatment. The DNA damage levels were compara-ble between clf-29 and wild type, even though several DNA damage repair genes (e.g. ATM, BRCA2a, RAD50, RAD51, RAD54,and PARP2) were expressed at lower levels in clf-29. Under bleomycin treatment, the expression levels of DNA repair genes were similar in clf-29 and wild type, thus CLF may also regulate HR via other mechanisms. These findings expand the current knowledge of PcG function and contribute to general interests of epigenetic regulation in genome stability regulation.

  13. Aldehyde dehydrogenases in Arabidopsis thaliana: Biochemical requirements, metabolic pathways and functional analysis

    Directory of Open Access Journals (Sweden)

    Naim eStiti

    2011-10-01

    Full Text Available Aldehyde dehydrogenases (ALDHs are a family of enzymes which catalyze the oxidation of reactive aldehydes to their corresponding carboxylic acids. Here we summarize molecular genetic and biochemical analyses of selected Arabidopsis ALDH genes. Aldehyde molecules are very reactive and are involved in many metabolic processes but when they accumulate in excess they become toxic. Thus activity of aldehyde dehydrogenases is important in regulating the homeostasis of aldehydes. Overexpression of some ALDH genes demonstrated an improved abiotic stress tolerance. Despite the fact that several reports are available describing a role for specific ALDHs, their precise physiological roles are often still unclear. Therefore a number of genetic and biochemical tools have been generated to address the function with an emphasis on stress-related ALDHs. ALDHs exert their functions in different cellular compartments and often in a developmental and tissue specific manner. To investigate substrate specificity, catalytic efficiencies have been determined using a range of substrates varying in carbon chain length and degree of carbon oxidation. Mutational approaches identified amino acid residues critical for coenzyme usage and enzyme activities.

  14. Aldehyde Dehydrogenases in Arabidopsis thaliana: Biochemical Requirements, Metabolic Pathways, and Functional Analysis.

    Science.gov (United States)

    Stiti, Naim; Missihoun, Tagnon D; Kotchoni, Simeon O; Kirch, Hans-Hubert; Bartels, Dorothea

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) are a family of enzymes which catalyze the oxidation of reactive aldehydes to their corresponding carboxylic acids. Here we summarize molecular genetic and biochemical analyses of selected ArabidopsisALDH genes. Aldehyde molecules are very reactive and are involved in many metabolic processes but when they accumulate in excess they become toxic. Thus activity of aldehyde dehydrogenases is important in regulating the homeostasis of aldehydes. Overexpression of some ALDH genes demonstrated an improved abiotic stress tolerance. Despite the fact that several reports are available describing a role for specific ALDHs, their precise physiological roles are often still unclear. Therefore a number of genetic and biochemical tools have been generated to address the function with an emphasis on stress-related ALDHs. ALDHs exert their functions in different cellular compartments and often in a developmental and tissue specific manner. To investigate substrate specificity, catalytic efficiencies have been determined using a range of substrates varying in carbon chain length and degree of carbon oxidation. Mutational approaches identified amino acid residues critical for coenzyme usage and enzyme activities.

  15. The RdDM Pathway Is Required for Basal Heat Tolerance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Olga V.Popova; Huy Q.Dinh; Werner Aufsatz; Claudia Jonak

    2013-01-01

    Heat stress affects epigenetic gene silencing in Arabidopsis.To test for a mechanistic involvement of epigenetic regulation in heat-stress responses,we analyzed the heat tolerance of mutants defective in DNA methylation,histone modifications,chromatin-remodeling,or siRNA-based silencing pathways.Plants deficient in NRPD2,the common second-largest subunit of RNA polymerases Ⅳ and V,and in the Rpd3-type histone deacetylase HDA6 were hypersensitive to heat exposure.Microarray analysis demonstrated that NRPD2 and HDA6 have independent roles in transcriptional reprogramming in response to temperature stress.The misexpression of protein-coding genes in nrpd2 mutants recovering from heat correlated with defective epigenetic regulation of adjacent transposon remnants which involved the loss of control of heat-stress-induced read-through transcription.We provide evidence that the transcriptional response to temperature stress,at least partially,relies on the integrity of the RNA-dependent DNA methylation pathway.

  16. MYB98 is required for pollen tube guidance and synergid cell differentiation in Arabidopsis.

    Science.gov (United States)

    Kasahara, Ryushiro D; Portereiko, Michael F; Sandaklie-Nikolova, Linda; Rabiger, David S; Drews, Gary N

    2005-11-01

    The synergid cells of the female gametophyte play a role in many steps of the angiosperm fertilization process, including guidance of pollen tube growth to the female gametophyte. However, the mechanisms by which the synergid cells become specified and develop their unique features during female gametophyte development are not understood. We identified MYB98 in a screen for Arabidopsis thaliana genes expressed in the female gametophyte. MYB98 is a member of the R2R3-MYB gene family, the members of which likely encode transcription factors. In the context of the ovule, MYB98 is expressed exclusively in the synergid cells, and mutations in this gene affect the female gametophyte specifically. myb98 female gametophytes are affected in two unique features of the synergid cell, pollen tube guidance and the filiform apparatus, but are otherwise normal. MYB98 also is expressed in trichomes and endosperm. Homozygous myb98 mutants exhibit no sporophytic defects, including trichome and endosperm defects. Together, these data suggest that MYB98 controls the development of specific features within the synergid cell during female gametophyte development.

  17. MYB98 Is Required for Pollen Tube Guidance and Synergid Cell Differentiation in ArabidopsisW⃞

    Science.gov (United States)

    Kasahara, Ryushiro D.; Portereiko, Michael F.; Sandaklie-Nikolova, Linda; Rabiger, David S.; Drews, Gary N.

    2005-01-01

    The synergid cells of the female gametophyte play a role in many steps of the angiosperm fertilization process, including guidance of pollen tube growth to the female gametophyte. However, the mechanisms by which the synergid cells become specified and develop their unique features during female gametophyte development are not understood. We identified MYB98 in a screen for Arabidopsis thaliana genes expressed in the female gametophyte. MYB98 is a member of the R2R3-MYB gene family, the members of which likely encode transcription factors. In the context of the ovule, MYB98 is expressed exclusively in the synergid cells, and mutations in this gene affect the female gametophyte specifically. myb98 female gametophytes are affected in two unique features of the synergid cell, pollen tube guidance and the filiform apparatus, but are otherwise normal. MYB98 also is expressed in trichomes and endosperm. Homozygous myb98 mutants exhibit no sporophytic defects, including trichome and endosperm defects. Together, these data suggest that MYB98 controls the development of specific features within the synergid cell during female gametophyte development. PMID:16214903

  18. Multiple BiP genes of Arabidopsis thaliana are required for male gametogenesis and pollen competitiveness.

    Science.gov (United States)

    Maruyama, Daisuke; Sugiyama, Tomoyuki; Endo, Toshiya; Nishikawa, Shuh-Ichi

    2014-04-01

    Immunoglobulin-binding protein (BiP) is a molecular chaperone of the heat shock protein 70 (Hsp70) family. BiP is localized in the endoplasmic reticulum (ER) and plays key roles in protein translocation, protein folding and quality control in the ER. The genomes of flowering plants contain multiple BiP genes. Arabidopsis thaliana has three BiP genes. BIP1 and BIP2 are ubiquitously expressed. BIP3 encodes a less well conserved BiP paralog, and it is expressed only under ER stress conditions in the majority of organs. Here, we report that all BiP genes are expressed and functional in pollen and pollen tubes. Although the bip1 bip2 double mutation does not affect pollen viability, the bip1 bip2 bip3 triple mutation is lethal in pollen. This result indicates that lethality of the bip1 bip2 double mutation is rescued by BiP3 expression. A decrease in the copy number of the ubiquitously expressed BiP genes correlates well with a decrease in pollen tube growth, which leads to reduced fitness of mutant pollen during fertilization. Because an increased protein secretion activity is expected to increase the protein folding demand in the ER, the multiple BiP genes probably cooperate with each other to ensure ER homeostasis in cells with active secretion such as rapidly growing pollen tubes.

  19. Appropriate Crypt Formation in the Uterus for Embryo Homing and Implantation Requires Wnt5a-ROR Signaling

    Directory of Open Access Journals (Sweden)

    Jeeyeon Cha

    2014-07-01

    Full Text Available Embryo homing and implantation occur within a crypt (implantation chamber at the antimesometrial (AM pole along the uterus. The mechanism by which this is achieved is not known. Here, we show that villi-like epithelial projections from the main uterine lumen toward the AM pole at regularly spaced intervals that form crypts for embryo implantation were disrupted in mice with uterine loss or gain of function of Wnt5a, or loss of function of both Ror1 and Ror2. This disruption of Wnt5a-ROR signaling resulted in disorderly epithelial projections, crypt formation, embryo spacing, and impaired implantation. These early disturbances under abnormal Wnt5a-ROR signaling were reflected in adverse late pregnancy events, including defective decidualization and placentation, ultimately leading to compromised pregnancy outcomes. This study presents deeper insight regarding the formation of organized epithelial projections for crypt formation and embryo implantation for pregnancy success.

  20. Arabidopsis WRKY33 transcription factor is required for resistance to necrotrophic fungal pathogens.

    Science.gov (United States)

    Zheng, Zuyu; Qamar, Synan Abu; Chen, Zhixiang; Mengiste, Tesfaye

    2006-11-01

    Plant WRKY transcription factors are key regulatory components of plant responses to microbial infection. In addition to regulating the expression of defense-related genes, WRKY transcription factors have also been shown to regulate cross-talk between jasmonate- and salicylate-regulated disease response pathways. The two pathways mediate resistance against different types of microbial pathogens, and there are numerous reports of antagonistic interactions between them. Here we show that mutations of the Arabidopsis WRKY33 gene encoding a WRKY transcription factor cause enhanced susceptibility to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola concomitant with reduced expression of the jasmonate-regulated plant defensin PDF1.2 gene. Ectopic over-expression of WRKY33, on the other hand, increases resistance to the two necrotrophic fungal pathogens. The wrky33 mutants do not show altered responses to a virulent strain of the bacterial pathogen Pseudomonas syringae, although the ectopic expression of WRKY33 results in enhanced susceptibility to this pathogen. The susceptibility of WRKY33-over-expressing plants to P. syringae is associated with reduced expression of the salicylate-regulated PR-1 gene. The WRKY33 transcript is induced in response to pathogen infection, or treatment with salicylate or the paraquat herbicide that generates activated oxygen species in exposed cells. WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence. Together, these results indicate that pathogen-induced WRKY33 is an important transcription factor that regulates the antagonistic relationship between defense pathways mediating responses to P. syringae and necrotrophic pathogens.

  1. Global Regulation of Embryonic Patterning in Arabidopsis by MicroRNAs1[W][OPEN

    Science.gov (United States)

    Seefried, William F.; Willmann, Matthew R.; Clausen, Rachel L.; Jenik, Pablo D.

    2014-01-01

    The development of the embryo in Arabidopsis (Arabidopsis thaliana) involves a carefully controlled set of cell divisions and cell fate decisions that lead to a mature embryo containing shoot and root meristems and all basic tissue types. Over the last 20 years, a number of transcriptional regulators of embryonic patterning have been described, but little is known about the role of posttranscriptional regulators such as microRNAs (miRNAs). Previous work has centered on the study of null or very weak alleles of miRNA biosynthetic genes, but these mutants either arrest early in embryogenesis or have wild-type-looking embryos. Here, we significantly extend those analyses by characterizing embryos mutant for a strong hypomorphic allele of DICER-LIKE1 (dcl1-15). Our data demonstrate that miRNAs are required for the patterning of most regions of the embryo, with the exception of the protoderm. In mutant embryos with the most severe morphological defects, the majority of tissue identities are lost. Different levels of miRNAs appear to be required to specify cell fates in various regions of the embryo. The suspensor needs the lowest levels, followed by the root apical meristem and hypocotyl, cotyledons, and shoot apical meristem. Furthermore, we show that erecta acts as a suppressor of dcl1-15, a novel role for this signaling pathway in embryos. Our results also indicate that the regulation of the messenger RNA levels of miRNA targets involves not just the action of miRNAs but has a significant transcriptional component as well. PMID:24784759

  2. 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.

  3. Differing requirements for RAD51 and DMC1 in meiotic pairing of centromeres and chromosome arms in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Olivier Da Ines

    Full Text Available During meiosis homologous chromosomes pair, recombine, and synapse, thus ensuring accurate chromosome segregation and the halving of ploidy necessary for gametogenesis. The processes permitting a chromosome to pair only with its homologue are not fully understood, but successful pairing of homologous chromosomes is tightly linked to recombination. In Arabidopsis thaliana, meiotic prophase of rad51, xrcc3, and rad51C mutants appears normal up to the zygotene/pachytene stage, after which the genome fragments, leading to sterility. To better understand the relationship between recombination and chromosome pairing, we have analysed meiotic chromosome pairing in these and in dmc1 mutant lines. Our data show a differing requirement for these proteins in pairing of centromeric regions and chromosome arms. No homologous pairing of mid-arm or distal regions was observed in rad51, xrcc3, and rad51C mutants. However, homologous centromeres do pair in these mutants and we show that this does depend upon recombination, principally on DMC1. This centromere pairing extends well beyond the heterochromatic centromere region and, surprisingly, does not require XRCC3 and RAD51C. In addition to clarifying and bringing the roles of centromeres in meiotic synapsis to the fore, this analysis thus separates the roles in meiotic synapsis of DMC1 and RAD51 and the meiotic RAD51 paralogs, XRCC3 and RAD51C, with respect to different chromosome domains.

  4. Requirement and Functional Redundancy of Ib Subgroup bHLH Proteins for Iron Deficiency Responses and Uptake in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Ning Wang; Yan Cui; Yi Liu; Huajie Fan; Juan Du; Zongan Huang; Youxi Yuan

    2013-01-01

    The Ib subgroup of the bHLH gene family in Arabidopsis contains four members (AtbHLH38,AtbHLH39,AtbHLHIO0,and AtbHLHI01).AtbHLH38 and AtbHLH39 were previously confirmed to interact with FER-like iron deficiency induced transcription factor (FIT),directly functioning in activation of the expression of ferric-chelate reductase FRO2 and high-affinity ferrous iron transporter IRT1.In this work,we characterized the functions of AtbHLH100 and AtbHLH101 in the regulation of the iron-deficiency responses and uptake.Yeast two-hybrid analysis and bimolecular fluorescence complementation assay demonstrated that both AtbHLH100 and AtbHLH101 could interact with FIT.Dual expression of either AtbHLHIO0 or AtbHLHI01 with FIT in yeast cells activated the GUS expression driven by promoters of FRO2 and IRT1.The plants overexpressing FIT together with AtbHLH101 showed constitutive expression of FRO2 and IRT1 in roots,and accumulated more iron in shoots.Further,the single,double,and triple knockout mutants of AtbHLH38,AtbHLH39,AtbHLHIO0,and AtbHLHI01 were generated and characterized.The FRO2 and IRT1 expression in roots and the iron content in shoots were more drastically decreased in the triple knockout mutant of AtbHLH39,AtbHLHI00,and AtbHLHI01 than that of the other available double and triple mutants of the four genes,Comparison of the physiological responses as well as the expression of FRO2 and IRT1 in the multiple knockout mutants under iron deficiency revealed that AtbHLH100,AtbHLH38,AtbHLH101,and AtbHLH39 played the gradually increased important role in the iron-deficiency responses and uptake.Taken all together,we conclude that the four Ib subgroup bHLH proteins are required and possess redundant functions with differential significance for activation of iron-deficiency responses and uptake in Arabidopsis.

  5. D6PK AGCVIII Kinases Are Required for Auxin Transport and Phototropic Hypocotyl Bending in Arabidopsis[C][W

    Science.gov (United States)

    Willige, Björn C.; Ahlers, Siv; Zourelidou, Melina; Barbosa, Inês C.R.; Demarsy, Emilie; Trevisan, Martine; Davis, Philip A.; Roelfsema, M. Rob G.; Hangarter, Roger; Fankhauser, Christian; Schwechheimer, Claus

    2013-01-01

    Phototropic hypocotyl bending in response to blue light excitation is an important adaptive process that helps plants to optimize their exposure to light. In Arabidopsis thaliana, phototropic hypocotyl bending is initiated by the blue light receptors and protein kinases phototropin1 (phot1) and phot2. Phototropic responses also require auxin transport and were shown to be partially compromised in mutants of the PIN-FORMED (PIN) auxin efflux facilitators. We previously described the D6 PROTEIN KINASE (D6PK) subfamily of AGCVIII kinases, which we proposed to directly regulate PIN-mediated auxin transport. Here, we show that phototropic hypocotyl bending is strongly dependent on the activity of D6PKs and the PIN proteins PIN3, PIN4, and PIN7. While early blue light and phot-dependent signaling events are not affected by the loss of D6PKs, we detect a gradual loss of PIN3 phosphorylation in d6pk mutants of increasing complexity that is most severe in the d6pk d6pkl1 d6pkl2 d6pkl3 quadruple mutant. This is accompanied by a reduction of basipetal auxin transport in the hypocotyls of d6pk as well as in pin mutants. Based on our data, we propose that D6PK-dependent PIN regulation promotes auxin transport and that auxin transport in the hypocotyl is a prerequisite for phot1-dependent hypocotyl bending. PMID:23709629

  6. The DNA replication factor RFC1 is required for interference-sensitive meiotic crossovers in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Yingxiang Wang

    Full Text Available During meiotic recombination, induced double-strand breaks (DSBs are processed into crossovers (COs and non-COs (NCO; the former are required for proper chromosome segregation and fertility. DNA synthesis is essential in current models of meiotic recombination pathways and includes only leading strand DNA synthesis, but few genes crucial for DNA synthesis have been tested genetically for their functions in meiosis. Furthermore, lagging strand synthesis has been assumed to be unnecessary. Here we show that the Arabidopsis thaliana DNA replication factor C1 (RFC1 important for lagging strand synthesis is necessary for fertility, meiotic bivalent formation, and homolog segregation. Loss of meiotic RFC1 function caused abnormal meiotic chromosome association and other cytological defects; genetic analyses with other meiotic mutations indicate that RFC1 acts in the MSH4-dependent interference-sensitive pathway for CO formation. In a rfc1 mutant, residual pollen viability is MUS81-dependent and COs exhibit essentially no interference, indicating that these COs form via the MUS81-dependent interference-insensitive pathway. We hypothesize that lagging strand DNA synthesis is important for the formation of double Holliday junctions, but not alternative recombination intermediates. That RFC1 is found in divergent eukaryotes suggests a previously unrecognized and highly conserved role for DNA synthesis in discriminating between recombination pathways.

  7. 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.

  8. 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.

  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. The synthetic cationic lipid diC14 activates a sector of the Arabidopsis defence network requiring endogenous signalling components.

    Science.gov (United States)

    Cambiagno, Damián Alejandro; Lonez, Caroline; Ruysschaert, Jean-Marie; Alvarez, María Elena

    2015-12-01

    Natural and synthetic elicitors have contributed significantly to the study of plant immunity. Pathogen-derived proteins and carbohydrates that bind to immune receptors, allow the fine dissection of certain defence pathways. Lipids of a different nature that act as defence elicitors, have also been studied, but their specific effects have been less well characterized, and their receptors have not been identified. In animal cells, nanoliposomes of the synthetic cationic lipid 3-tetradecylamino-tert-butyl-N-tetradecylpropionamidine (diC14) activate the TLR4-dependent immune cascade. Here, we have investigated whether this lipid induces Arabidopsis defence responses. At the local level, diC14 activated early and late defence gene markers (FRK1, WRKY29, ICS1 and PR1), acting in a dose-dependent manner. This lipid induced the salicylic acid (SA)-dependent, but not jasmonic acid (JA)-dependent, pathway and protected plants against Pseudomonas syringae pv. tomato (Pst), but not Botrytis cinerea. diC14 was not toxic to plant or pathogen, and potentiated pathogen-induced callose deposition. At the systemic level, diC14 induced PR1 expression and conferred resistance against Pst. diC14-induced defence responses required the signalling protein EDS1, but not NDR1. Curiously, the lipid-induced defence gene expression was lower in the fls2/efr/cerk1 triple mutant, but still unchanged in the single mutants. The amidine headgroup and chain length were important for its activity. Given the robustness of the responses triggered by diC14, its specific action on a defence pathway and the requirement for well-known defence components, this synthetic lipid is emerging as a useful tool to investigate the initial events involved in plant innate immunity.

  11. MYB75 phosphorylation by MPK4 is required for light-induced anthocyanin accumulation in arabidopsis

    DEFF Research Database (Denmark)

    Li, Shengnan; Wang, Wenyi; Gao, Jinlan

    2016-01-01

    anthocyanin pigments is light dependent, and the R2R3 MYB transcription factor MYB75/PAP1 regulates anthocyanin accumulation. Here, we report that MYB75 interacts with and is phosphorylated by MAP KINASE4 (MPK4). Their interaction is dependent on MPK4 kinase activity and is required for full function of MYB75...

  12. Stabilization of Arabidopsis DREB2A is required but not sufficient for the induction of target genes under conditions of stress.

    Directory of Open Access Journals (Sweden)

    Kyoko Morimoto

    Full Text Available The Arabidopsis thaliana transcription factor DEHYDRATION-RESPONSIVE ELEMENT-BINDING PROTEIN2A (DREB2A controls the expression of many genes involved in the plant's response to dehydration and heat stress. Despite the significance of post-translational regulation in DREB2A activation, the mechanism underlying this activation remains unclear. Here, with the aid of a newly produced antibody against DREB2A, we characterized the regulation of DREB2A stability in plants exposed to stress stimuli. Endogenous DREB2A accumulated in wild-type Arabidopsis plants subjected to dehydration and heat stress. A degradation assay using Arabidopsis T87 suspension-cultured cells revealed that DREB2A protein degradation was inhibited at high temperatures. The proteasome-dependent degradation of DREB2A required the import of this protein into the nucleus. The E3 ligases DRIP1 and DRIP2 were involved in this process under both normal and stressful conditions; however, other E3 ligases may have also been involved, at least during the late stages of the heat stress response. Although the constitutive expression of DREB2A resulted in an overproduction of DREB2A and enhanced target gene induction during stress in transgenic plants, the accumulation of DREB2A caused by proteasome inhibitors did not induce target gene expression. Thus, the stabilization of DREB2A is important but not sufficient to induce target gene expression; further activation processes are required.

  13. 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

  14. 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

  15. Apelin, the ligand for the endothelial G-protein-coupled receptor, APJ, is a potent angiogenic factor required for normal vascular development of the frog embryo.

    Science.gov (United States)

    Cox, Christopher M; D'Agostino, Susan L; Miller, Melanie K; Heimark, Ronald L; Krieg, Paul A

    2006-08-01

    The peptide growth factor apelin is the high affinity ligand for the G-protein-coupled receptor APJ. During embryonic development of mouse and frog, APJ receptor is expressed at high levels in endothelial precursor cells and in nascent vascular structures. Characterization of Xenopus apelin shows that the sequence of the bioactive region of the peptide is perfectly conserved between frogs and mammals. Embryonic expression studies indicate that apelin is expressed in, or immediately adjacent to, a subset of the developing vascular structures, particularly the intersegmental vessels. Experimental inhibition of either apelin or APJ expression, using antisense morpholino oligos, results in elimination or disruption of intersegmental vessels in a majority of embryos. In gain of function experiments, apelin peptide is a potent angiogenic factor when tested using two in vivo angiogenesis assays, the frog embryo and the chicken chorioallantoic membrane. Furthermore, studies using the mouse brain microvascular cell line bEnd.3 show that apelin acts as a mitogenic, chemotactic and anti-apoptotic agent for endothelial cells in culture. Finally, we show that, similar to a number of other angiogenic factors, expression of the apelin gene is increased under conditions of hypoxia. Taken together, these studies indicate that apelin is required for normal vascular development in the frog embryo and has properties consistent with a role during normal and pathological angiogenesis.

  16. Arabidopsis ANGULATA10 is required for thylakoid biogenesis and mesophyll development.

    Science.gov (United States)

    Casanova-Sáez, Rubén; Mateo-Bonmatí, Eduardo; Kangasjärvi, Saijaliisa; Candela, Héctor; Micol, José Luis

    2014-06-01

    The chloroplasts of land plants contain internal membrane systems, the thylakoids, which are arranged in stacks called grana. Because grana have not been found in Cyanobacteria, the evolutionary origin of genes controlling the structural and functional diversification of thylakoidal membranes in land plants remains unclear. The angulata10-1 (anu10-1) mutant, which exhibits pale-green rosettes, reduced growth, and deficient leaf lateral expansion, resulting in the presence of prominent marginal teeth, was isolated. Palisade cells in anu10-1 are larger and less packed than in the wild type, giving rise to large intercellular spaces. The ANU10 gene encodes a protein of unknown function that localizes to both chloroplasts and amyloplasts. In chloroplasts, ANU10 associates with thylakoidal membranes. Mutant anu10-1 chloroplasts accumulate H2O2, and have reduced levels of chlorophyll and carotenoids. Moreover, these chloroplasts are small and abnormally shaped, thylakoidal membranes are less abundant, and their grana are absent due to impaired thylakoid stacking in the anu10-1 mutant. Because the trimeric light-harvesting complex II (LHCII) has been reported to be required for thylakoid stacking, its levels were determined in anu10-1 thylakoids and they were found to be reduced. Together, the data point to a requirement for ANU10 for chloroplast and mesophyll development.

  17. Natural Variation Identifies ICARUS1, a Universal Gene Required for Cell Proliferation and Growth at High Temperatures in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Wangsheng Zhu

    2015-05-01

    Full Text Available Plants are highly sensitive to environmental changes and even small variations in ambient temperature have severe consequences on their growth and development. Temperature affects multiple aspects of plant development, but the processes and mechanisms underlying thermo-sensitive growth responses are mostly unknown. Here we exploit natural variation in Arabidopsis thaliana to identify and characterize novel components and processes mediating thermo-sensitive growth responses in plants. Phenotypic screening of wild accessions identified several strains displaying pleiotropic growth defects, at cellular and organism levels, specifically at high ambient temperatures. Positional cloning and characterization of the underlying gene revealed that ICARUS1 (ICA1, which encodes a protein of the tRNAHis guanylyl transferase (Thg1 superfamily, is required for plant growth at high temperatures. Transcriptome and gene marker analyses together with DNA content measurements show that ICA1 loss-of-function results in down regulation of cell cycle associated genes at high temperatures, which is linked with a block in G2/M transition and endoreduplication. In addition, plants with mutations in ICA1 show enhanced sensitivity to DNA damage. Characterization of additional strains that carry lesions in ICA1, but display normal growth, shows that alternative splicing is likely to alleviate the deleterious effects of some natural mutations. Furthermore, analyses of worldwide and regional collections of natural accessions indicate that ICA1 loss-of-function has arisen several times independently, and that these occur at high frequency in some local populations. Overall our results suggest that ICA1-mediated-modulation of fundamental processes such as tRNAHis maturation, modify plant growth responses to temperature changes in a quantitative and reversible manner, in natural populations.

  18. The Blue Light-Dependent Polyubiquitination and Degradation of Arabidopsis Cryptochrome2 Requires Multiple E3 Ubiquitin Ligases.

    Science.gov (United States)

    Liu, Qing; Wang, Qin; Liu, Bin; Wang, Wei; Wang, Xu; Park, Joon; Yang, Zhenming; Du, Xinglin; Bian, Mingdi; Lin, Chentao

    2016-10-01

    Cryptochromes are blue light receptors regulated by light-dependent ubiquitination and degradation in both plant and animal lineages. The Arabidopsis genome encodes two cryptochromes, CRY1 and CRY2, of which CRY2 undergoes blue light-dependent ubiquitination and 26S proteasome-dependent degradation. The molecular mechanism regulating blue light-dependent proteolysis of CRY2 is still not fully understood. We found that the F-box proteins ZEITLUPE (ZTL) and Lov Kelch Protein2 (LKP2), which mediate blue light suppression of degradation of the CRY2 signaling partner CIB1, are not required for the blue light-dependent CRY2 degradation. We further showed that the previously reported function of the COP1-SPA1 protein complex in blue light-dependent CRY2 degradation is more likely to be attributable to its cullin 4 (CUL4)-based E3 ubiquitin ligase activity than its activity as the cryptochrome signaling partner. However, the blue light-dependent CRY2 degradation is only partially impaired in the cul4 mutant, the cop1-5 null mutant and the spa1234 quadruple mutant, suggesting a possible involvement of additional E3 ubiquitin ligases in the regulation of CRY2. Consistent with this hypothesis, we demonstrated that the blue light-dependent CRY2 degradation is significantly impaired in the temperature-sensitive cul1 mutant allele (axr6-3), especially under the non-permissive temperature. Based on these and other results presented, we propose that photoexcited CRY2 undergoes Lys48-linked polyubiquitination catalyzed by the CUL4- and CUL1-based E3 ubiquitin ligases.

  19. Rice blast fungus (Magnaporthe oryzae) infects Arabidopsis via a mechanism distinct from that required for the infection of rice.

    Science.gov (United States)

    Park, Ju-Young; Jin, Jianming; Lee, Yin-Won; Kang, Seogchan; Lee, Yong-Hwan

    2009-01-01

    Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice (Oryza sativa) blast. Although M. oryzae as a whole infects a wide variety of monocotyledonous hosts, no dicotyledonous plant has been reported as a host. We found that two rice pathogenic strains of M. oryzae, KJ201 and 70-15, interacted differentially with 16 ecotypes of Arabidopsis (Arabidopsis thaliana). Strain KJ201 infected all ecotypes with varying degrees of virulence, whereas strain 70-15 caused no symptoms in certain ecotypes. In highly susceptible ecotypes, small chlorotic lesions appeared on infected leaves within 3 d after inoculation and subsequently expanded across the affected leaves. The fungus produced spores in susceptible ecotypes but not in resistant ecotypes. Fungal cultures recovered from necrotic lesions caused the same symptoms in healthy plants, satisfying Koch's postulates. Histochemical analyses showed that infection by the fungus caused an accumulation of reactive oxygen species and eventual cell death. Similar to the infection process in rice, the fungus differentiated to form appressorium and directly penetrated the leaf surface in Arabidopsis. However, the pathogenic mechanism in Arabidopsis appears distinct from that in rice; three fungal genes essential for pathogenicity in rice played only limited roles in causing disease symptoms in Arabidopsis, and the fungus seems to colonize Arabidopsis as a necrotroph through the secretion of phytotoxic compounds, including 9,12-octadecadienoic acid. Expression of PR-1 and PDF1.2 was induced in response to infection by the fungus, suggesting the activation of salicylic acid- and jasmonic acid/ethylene-dependent signaling pathways. However, the roles of these signaling pathways in defense against M. oryzae remain unclear. In combination with the wealth of genetic and genomic resources available for M. oryzae, this newly established pathosystem allows comparison of the molecular and cellular mechanisms underlying

  20. Successful fertilization requires the presence of at least one major O-acetylserine(thiol)lyase for cysteine synthesis in pollen of Arabidopsis.

    Science.gov (United States)

    Birke, Hannah; Heeg, Corinna; Wirtz, Markus; Hell, Rüdiger

    2013-10-01

    The synthesis of cysteine (Cys) is a master control switch of plant primary metabolism that coordinates the flux of sulfur with carbon and nitrogen metabolism. In Arabidopsis (Arabidopsis thaliana), nine genes encode for O-acetylserine(thiol)lyase (OAS-TL)-like proteins, of which the major isoforms, OAS-TL A, OAS-TL B, and OAS-TL C, catalyze the formation of Cys by combining O-acetylserine and sulfide in the cytosol, the plastids, and the mitochondria, respectively. So far, the significance of individual OAS-TL-like enzymes is unresolved. Generation of all major OAS-TL double loss-of-function mutants in combination with radiolabeled tracer studies revealed that subcellular localization of OAS-TL proteins is more important for efficient Cys synthesis than total cellular OAS-TL activity in leaves. The absence of oastl triple embryos after targeted crosses indicated the exclusiveness of Cys synthesis by the three major OAS-TLs and ruled out alternative sulfur fixation by other OAS-TL-like proteins. Analyses of oastlABC pollen demonstrated that the presence of at least one functional OAS-TL isoform is essential for the proper function of the male gametophyte, although the synthesis of histidine, lysine, and tryptophan is dispensable in pollen. Comparisons of oastlABC pollen derived from genetically different parent plant combinations allowed us to separate distinct functions of Cys and glutathione in pollen and revealed an additional role of glutathione for pollen germination. In contrast, female gametogenesis was not affected by the absence of major OAS-TLs, indicating significant transport of Cys into the developing ovule from the mother plant.

  1. The Arabidopsis DESPERADO/AtWBC11 transporter is required for cutin and wax secretion.

    Science.gov (United States)

    Panikashvili, David; Savaldi-Goldstein, Sigal; Mandel, Tali; Yifhar, Tamar; Franke, Rochus B; Höfer, René; Schreiber, Lukas; Chory, Joanne; Aharoni, Asaph

    2007-12-01

    The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C(16-18) fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses.

  2. Iron-regulated metabolites produced by Pseudomonas fluorescens WCS374r are not required for eliciting induced systemic resistance against Pseudomonas syringae pv. tomato in Arabidopsis.

    Science.gov (United States)

    Djavaheri, Mohammad; Mercado-Blanco, Jesús; Versluis, C; Meyer, J-M; Loon, L C; Bakker, Peter A H M

    2012-09-01

    The plant growth-promoting rhizobacterium Pseudomonas fluorescens WCS374r produces several iron-regulated metabolites, including the fluorescent siderophore pseudobactin (Psb374), salicylic acid (SA), and pseudomonine (Psm), a siderophore that contains a SA moiety. After purification of Psb374 from culture supernatant of WCS374r, its structure was determined following isoelectrofocusing and tandem mass spectrometry, and found to be identical to the fluorescent siderophore produced by P. fluorescens ATCC 13525. To study the role of SA and Psm production in colonization of Arabidopsis thaliana roots and in induced systemic resistance (ISR) against Pseudomonas syringae pv. tomato (Pst) by strain WCS374r, mutants disrupted in the production of these metabolites were obtained by homologous recombination. These mutants were further subjected to transposon Tn5 mutagenesis to generate mutants also deficient in Psb374 production. The mutants behaved similar to the wild type in both their Arabidopsis rhizosphere-colonizing capacity and their ability to elicit ISR against Pst. We conclude that Psb374, SA, and Psm production by P. fluorescens WCS374r are not required for eliciting ISR in Arabidopsis.

  3. Requirement for the plastidial oxidative pentose phosphate pathway for nitrate assimilation in Arabidopsis.

    Science.gov (United States)

    Bussell, John D; Keech, Olivier; Fenske, Ricarda; Smith, Steven M

    2013-08-01

    Sugar metabolism and the oxidative pentose phosphate pathway (OPPP) are strongly implicated in N assimilation, although the relationship between them and the roles of the plastidial and cytosolic OPPP have not been established genetically. We studied a knock-down mutant of the plastid-localized OPPP enzyme 6-phosphogluconolactonase 3 (PGL3). pgl3-1 plants exhibited relatively greater resource allocation to roots but were smaller than the wild type. They had a lower content of amino acids and free NO3 - in leaves than the wild type, despite exhibiting comparable photosynthetic rates and efficiency, and normal levels of many other primary metabolites. When N-deprived plants were fed via the roots with 15NO3 -, pgl3-1 exhibited normal induction of OPPP and nitrate assimilation genes in roots, and amino acids in roots and shoots were labeled with (15) N at least as rapidly as in the wild type. However, when N-replete plants were fed via the roots with sucrose, expression of specific OPPP and N assimilation genes in roots increased in the wild type but not in pgl3-1. Thus, sugar-dependent expression of N assimilation genes requires OPPP activity and the specificity of the effect of the pgl3-1 mutation on N assimilation genes establishes that it is not the result of general energy deficiency or accumulation of toxic intermediates. We conclude that expression of specific nitrate assimilation genes in the nucleus of root cells is positively regulated by a signal emanating from OPPP activity in the plastid.

  4. 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.

  5. Systemic resistance in Arabidopsis induced by rhizobacteria requires ethylene-dependent signaling at the site of application

    NARCIS (Netherlands)

    Knoester, M.; Pieterse, C.M.J.; Bol, J.F.; Loon, L.C. van

    1999-01-01

    Root colonization of Arabidopsis thaliana by the nonpathogenic, rhizosphere-colonizing, biocontrol bacterium Pseudomonas fluorescens WCS417r has been shown to elicit induced systemic resistance (ISR) against Pseudomonas syringae pv. tomato (Pst). The ISR response differs from the pathogen-inducible

  6. Arabidopsis Deficient in Cutin Ferulate encodes a transferase required for feruloylation of ω-hydroxy fatty acids in cutin polyester.

    Science.gov (United States)

    Rautengarten, Carsten; Ebert, Berit; Ouellet, Mario; Nafisi, Majse; Baidoo, Edward E K; Benke, Peter; Stranne, Maria; Mukhopadhyay, Aindrila; Keasling, Jay D; Sakuragi, Yumiko; Scheller, Henrik Vibe

    2012-02-01

    The cuticle is a complex aliphatic polymeric layer connected to the cell wall and covers surfaces of all aerial plant organs. The cuticle prevents nonstomatal water loss, regulates gas exchange, and acts as a barrier against pathogen infection. The cuticle is synthesized by epidermal cells and predominantly consists of an aliphatic polymer matrix (cutin) and intracuticular and epicuticular waxes. Cutin monomers are primarily C(16) and C(18) unsubstituted, ω-hydroxy, and α,ω-dicarboxylic fatty acids. Phenolics such as ferulate and p-coumarate esters also contribute to a minor extent to the cutin polymer. Here, we present the characterization of a novel acyl-coenzyme A (CoA)-dependent acyl-transferase that is encoded by a gene designated Deficient in Cutin Ferulate (DCF). The DCF protein is responsible for the feruloylation of ω-hydroxy fatty acids incorporated into the cutin polymer of aerial Arabidopsis (Arabidopsis thaliana) organs. The enzyme specifically transfers hydroxycinnamic acids using ω-hydroxy fatty acids as acyl acceptors and hydroxycinnamoyl-CoAs, preferentially feruloyl-CoA and sinapoyl-CoA, as acyl donors in vitro. Arabidopsis mutant lines carrying DCF loss-of-function alleles are devoid of rosette leaf cutin ferulate and exhibit a 50% reduction in ferulic acid content in stem insoluble residues. DCF is specifically expressed in the epidermis throughout all green Arabidopsis organs. The DCF protein localizes to the cytosol, suggesting that the feruloylation of cutin monomers takes place in the cytoplasm.

  7. Different requirements for EDS1 and NDR1 by disease resistance genes define at least two R gene-mediated signaling pathways in Arabidopsis.

    Science.gov (United States)

    Aarts, N; Metz, M; Holub, E; Staskawicz, B J; Daniels, M J; Parker, J E

    1998-08-18

    The Arabidopsis genes EDS1 and NDR1 were shown previously by mutational analysis to encode essential components of race-specific disease resistance. Here, we examined the relative requirements for EDS1 and NDR1 by a broad spectrum of Resistance (R) genes present in three Arabidopsis accessions (Columbia, Landsberg-erecta, and Wassilewskija). We show that there is a strong requirement for EDS1 by a subset of R loci (RPP2, RPP4, RPP5, RPP21, and RPS4), conferring resistance to the biotrophic oomycete Peronospora parasitica, and to Pseudomonas bacteria expressing the avirulence gene avrRps4. The requirement for NDR1 by these EDS1-dependent R loci is either weak or not measurable. Conversely, three NDR1-dependent R loci, RPS2, RPM1, and RPS5, operate independently of EDS1. Another RPP locus, RPP8, exhibits no strong exclusive requirement for EDS1 or NDR1 in isolate-specific resistance to P. parasitica, although resistance is compromised weakly by eds1. Similarly, resistance conditioned by two EDS1-dependent RPP genes, RPP4 and RPP5, is impaired partially by ndr1, implicating a degree of pathway cross-talk. Our results provide compelling evidence for the preferential utilization of either signaling component by particular R genes and thus define at least two disease resistance pathways. The data also suggest that strong dependence on EDS1 or NDR1 is governed by R protein structural type rather than pathogen class.

  8. Arabidopsis Phosphoglycerate Dehydrogenase1 of the Phosphoserine Pathway Is Essential for Development and Required for Ammonium Assimilation and Tryptophan Biosynthesis[C][W][OPEN

    Science.gov (United States)

    Benstein, Ruben Maximilian; Ludewig, Katja; Wulfert, Sabine; Wittek, Sebastian; Gigolashvili, Tamara; Frerigmann, Henning; Gierth, Markus; Flügge, Ulf-Ingo; Krueger, Stephan

    2013-01-01

    In plants, two independent serine biosynthetic pathways, the photorespiratory and glycolytic phosphoserine (PS) pathways, have been postulated. Although the photorespiratory pathway is well characterized, little information is available on the function of the PS pathway in plants. Here, we present a detailed characterization of phosphoglycerate dehydrogenases (PGDHs) as components of the PS pathway in Arabidopsis thaliana. All PGDHs localize to plastids and possess similar kinetic properties, but they differ with respect to their sensitivity to serine feedback inhibition. Furthermore, analysis of pgdh1 and phosphoserine phosphatase mutants revealed an embryo-lethal phenotype and PGDH1-silenced lines were inhibited in growth. Metabolic analyses of PGDH1-silenced lines grown under ambient and high CO2 conditions indicate a direct link between PS biosynthesis and ammonium assimilation. In addition, we obtained several lines of evidence for an interconnection between PS and tryptophan biosynthesis, because the expression of PGDH1 and PHOSPHOSERINE AMINOTRANSFERASE1 is regulated by MYB51 and MYB34, two activators of tryptophan biosynthesis. Moreover, the concentration of tryptophan-derived glucosinolates and auxin were reduced in PGDH1-silenced plants. In essence, our results provide evidence for a vital function of PS biosynthesis for plant development and metabolism. PMID:24368794

  9. The nuclear protein Poly(ADP-ribose) polymerase 3 (AtPARP3) is required for seed storability in Arabidopsis thaliana.

    Science.gov (United States)

    Rissel, D; Losch, J; Peiter, E

    2014-11-01

    The deterioration of seeds during prolonged storage results in a reduction of viability and germination rate. DNA damage is one of the major cellular defects associated with seed deterioration. It is provoked by the formation of reactive oxygen species (ROS) even in the quiescent state of the desiccated seed. In contrast to other stages of seed life, DNA repair during storage is hindered through the low seed water content; thereby DNA lesions can accumulate. To allow subsequent seedling development, DNA repair has thus to be initiated immediately upon imbibition. Poly(ADP-ribose) polymerases (PARPs) are important components in the DNA damage response in humans. Arabidopsis thaliana contains three homologues to the human HsPARP1 protein. Of these three, only AtPARP3 was very highly expressed in seeds. Histochemical GUS staining of embryos and endosperm layers revealed strong promoter activity of AtPARP3 during all steps of germination. This coincided with high ROS activity and indicated a role of the nuclear-localised AtPARP3 in DNA repair during germination. Accordingly, stored parp3-1 mutant seeds lacking AtPARP3 expression displayed a delay in germination as compared to Col-0 wild-type seeds. A controlled deterioration test showed that the mutant seeds were hypersensitive to unfavourable storage conditions. The results demonstrate that AtPARP3 is an important component of seed storability and viability.

  10. Matefin/SUN-1 Phosphorylation on Serine 43 Is Mediated by CDK-1 and Required for Its Localization to Centrosomes and Normal Mitosis in C. elegans Embryos

    Directory of Open Access Journals (Sweden)

    Noam Zuela

    2016-02-01

    Full Text Available Matefin/SUN-1 is an evolutionary conserved C. elegans inner nuclear membrane SUN-domain protein. By creating a bridge with the KASH-domain protein ZYG-12, it connects the nucleus to cytoplasmic filaments and organelles. Matefin/SUN-1 is expressed in the germline where it undergoes specific phosphorylation at its N-terminal domain, which is required for germline development and homologous chromosome pairing. The maternally deposited matefin/SUN-1 is then essential for embryonic development. Here, we show that in embryos, serine 43 of matefin/SUN-1 (S43 is phosphorylated in a CDK-1 dependent manner and is localized throughout the cell cycle mostly to centrosomes. By generating animals expressing phosphodead S43A and phosphomimetic S43E mutations, we show that phosphorylation of S43 is required to maintain centrosome integrity and function, as well as for the localization of ZYG-12 and lamin. Expression of S43E in early embryos also leads to an increase in chromatin structural changes, decreased progeny and to almost complete embryonic lethality. Down regulation of emerin further increases the occurrence of chromatin organization abnormalities, indicating possible collaborative roles for these proteins that is regulated by S43 phosphorylation. Taken together, these results support a role for phosphorylation of serine 43 in matefin/SUN-1 in mitosis.

  11. Brassinosteroid Regulates Seed Size and Shape in Arabidopsis1[W][OPEN

    Science.gov (United States)

    Jiang, Wen-Bo; Huang, Hui-Ya; Hu, Yu-Wei; Zhu, Sheng-Wei; Wang, Zhi-Yong; Lin, Wen-Hui

    2013-01-01

    Seed development is important for agriculture productivity. We demonstrate that brassinosteroid (BR) plays crucial roles in determining the size, mass, and shape of Arabidopsis (Arabidopsis thaliana) seeds. The seeds of the BR-deficient mutant de-etiolated2 (det2) are smaller and less elongated than those of wild-type plants due to a decreased seed cavity, reduced endosperm volume, and integument cell length. The det2 mutant also showed delay in embryo development, with reduction in both the size and number of embryo cells. Pollination of det2 flowers with wild-type pollen yielded seeds of normal size but still shortened shape, indicating that the BR produced by the zygotic embryo and endosperm is sufficient for increasing seed volume but not for seed elongation, which apparently requires BR produced from maternal tissues. BR activates expression of SHORT HYPOCOTYL UNDER BLUE1, MINISEED3, and HAIKU2, which are known positive regulators of seed size, but represses APETALA2 and AUXIN RESPONSE FACTOR2, which are negative regulators of seed size. These genes are bound in vivo by the BR-activated transcription factor BRASSINAZOLE-RESISTANT1 (BZR1), and they are known to influence specific processes of integument, endosperm, and embryo development. Our results demonstrate that BR regulates seed size and seed shape by transcriptionally modulating specific seed developmental pathways. PMID:23771896

  12. Myrigalone A inhibits Lepidium sativum seed germination by interference with gibberellin metabolism and apoplastic superoxide production required for embryo extension growth and endosperm rupture.

    Science.gov (United States)

    Oracz, Krystyna; Voegele, Antje; Tarkowská, Danuse; Jacquemoud, Dominique; Turecková, Veronika; Urbanová, Terezie; Strnad, Miroslav; Sliwinska, Elwira; Leubner-Metzger, Gerhard

    2012-01-01

    Myrica gale L. (sweet gale) fruit leachate contains myrigalone A (MyA), a rare C-methylated dihydrochalcone and putative allelochemical, which is known to be a phytotoxin impeding seedling growth. We found that MyA inhibited Lepidium sativum L. seed germination in a dose-dependent manner. MyA did not affect testa rupture, but inhibited endosperm rupture and the transition to subsequent seedling growth. MyA inhibited micropylar endosperm cap (CAP) weakening and the increase in the growth potential of the radical/hypocotyl region (RAD) of the embryo, both being key processes required for endosperm rupture. We compared the contents of abscisic acid (ABA) and gibberellins in the tissues and found that the major bioactive forms of gibberellin in L. sativum seed tissues were GA(4) and GA(6), while GA(8) and GA(13) were abundant inactive metabolites. MyA did not appreciably affect the ABA contents, but severely interfered with gibberellin metabolism and signaling by inhibiting important steps catalyzed by GA3 oxidase, as well as by interfering with the GID1-type gibberellin signaling pathway. The hormonally and developmentally regulated formation of apoplastic superoxide radicals is important for embryo growth. Specific zones within the RAD were associated with accumulation of apoplastic superoxide radicals and endoreduplication indicative of embryo cell extension. MyA negatively affected both of these processes and acted as a scavenger of apoplastic reactive oxygen species. We propose that MyA is an allelochemical with a novel mode of action on seed germination.

  13. Thymocyte clones from 14-day mouse embryos. I. State of T cell receptor genes, surface markers, and growth requirements

    OpenAIRE

    1987-01-01

    We have established in culture 13 clones from the thymus of a 14-d B10.BR mouse embryo and characterized 8 of them. All eight FT clones have the TCR-gamma and -beta genes in germline configuration. They express mRNA for the gamma, but not for the beta nor the alpha genes. All eight FT clones are Thy-1+, Ly-1+, LFA-1+, Pgp-1+, H-2K+, and T3-. Three phenotypes could be distinguished on the basis of Lyt-2, L3T4, and IL-2-R expression: Lyt-2+, L3T4-, IL-2-R+ (I); Lyt-2+, L3T4-, IL-2- R- (II); and...

  14. Raldh expression in embryos of the direct developing frog Eleutherodactylus coqui and the conserved retinoic acid requirement for forelimb initiation.

    Science.gov (United States)

    Elinson, Richard P; Walton, Zachary; Nath, Kimberly

    2008-11-15

    Embryos of the direct developing frog, Eleutherodactylus coqui, provide opportunities to examine frog early limb development that are not available in species with tadpoles. We cloned two retinaldehyde dehydrogenase genes, EcRaldh1 and EcRaldh2, to see which enzyme likely supplies retinoic acid for limb development. EcRaldh1 is expressed in the dorsal retina, otic vesicle, pronephros, and pronephric duct, but not in the limb. EcRaldh2 is expressed early at the blastoporal lip and then in the mesoderm in the neurula, so this expression could function in forelimb initiation. Later EcRaldh2 is expressed in the mesoderm at the base of the limbs and in the ventral spinal cord where motor neurons innervating the limbs emerge. These observations on a frog support the functional conservation of EcRaldh2 in forelimb initiation in Osteichthyans and in limb patterning and motor neuron specification in tetrapods.

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

    OpenAIRE

    Muraro, Daniele; Mellor, Nathan; Pound, Michael P.; Help, Hanna; Lucas, Mikael; Chopard, Jerome; Byrne, Helen M.; GODIN, CHRISTOPHE; Hodgman, T. Charlie; King, John R.; Pridmore, Tony P.; Helariutta, Ykä; Bennett, Malcolm J; Bishopp, Anthony

    2014-01-01

    International audience; 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 micr...

  16. 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.

  17. The circadian clock has transient plasticity of period and is required for timing of nocturnal processes in Arabidopsis.

    Science.gov (United States)

    Dodd, Antony N; Dalchau, Neil; Gardner, Michael J; Baek, Seong-Jin; Webb, Alex A R

    2014-01-01

    A circadian rhythm matched to the phase and period of the day-night cycle has measurable benefits for land plants. We assessed the contribution of circadian period to the phasing of cellular events with the light : dark cycle. We also investigated the plasticity of circadian period within the Arabidopsis circadian oscillator. We monitored the circadian oscillator in wild-type and circadian period mutants under light : dark cycles of varying total duration. We also investigated changes in oscillator dynamics during and after the transition from light : dark cycles to free running conditions. Under light : dark cycles, dawn and dusk were anticipated differently when the circadian period was not resonant with the environmental period ('T cycle'). Entrainment to T cycles differing from the free-running period caused a short-term alteration in oscillator period. The transient plasticity of period was described by existing mathematical models of the Arabidopsis circadian network. We conclude that a circadian period resonant with the period of the environment is particularly important for anticipation of dawn and the timing of nocturnal events; and there is short-term and transient plasticity of period of the Arabidopsis circadian network.

  18. Nitric oxide accumulation is required to protect against iron-mediated oxidative stress in frataxin-deficient Arabidopsis plants.

    Science.gov (United States)

    Martin, Mariana; Colman, María José Rodríguez; Gómez-Casati, Diego F; Lamattina, Lorenzo; Zabaleta, Eduardo Julián

    2009-02-04

    Frataxin is a mitochondrial protein that is conserved throughout evolution. In yeast and mammals, frataxin is essential for cellular iron (Fe) homeostasis and survival during oxidative stress. In plants, frataxin deficiency causes increased reactive oxygen species (ROS) production and high sensitivity to oxidative stress. In this work we show that a knock-down T-DNA frataxin-deficient mutant of Arabidopsis thaliana (atfh-1) contains increased total and organellar Fe levels. Frataxin deficiency leads also to nitric oxide (NO) accumulation in both, atfh-1 roots and frataxin null mutant yeast. Abnormally high NO production might be part of the defence mechanism against Fe-mediated oxidative stress.

  19. The Arabidopsis P4-ATPase ALA3 requires a ß-subunit to function in phospholipid translocation and secretory vesicle formation

    DEFF Research Database (Denmark)

    Lopez Marques, Rosa Laura

    and in inducing membrane curvature, which is a requirement for vesicle formation. We show that Aminophospholipid ATPase3 (ALA3), a member of the P4-ATPase subfamily in the plant Arabidopsis thaliana, localizes to the Golgi apparatus and that genetic lesions of ALA3 result in impaired growth of roots and shoots....... The root growth defect is accompanied by the failure of the root to release border cells of the root cap. Electron micrograph data suggest that functioning and shedding of border cells are dependent on ALA3, as ala3 mutants are devoid of the characteristic proliferation of slime vesicles at the trans-Golgi...... and transport studies in yeast, at least one member of this family, ALIS1, is likely to serve as an essential ß-subunit of ALA3. We propose that the ALA3/ALIS1 protein complex forms an important part of the Golgi machinery required for secretory processes during plant development. We are currently aiming...

  20. A DEAD box protein is required for formation of a hidden break in Arabidopsis chloroplast 23S rRNA.

    Science.gov (United States)

    Nishimura, Kenji; Ashida, Hiroki; Ogawa, Taro; Yokota, Akiho

    2010-09-01

    In plant chloroplasts, the ribosomal RNA (rRNA) of the large subunit of the ribosome undergoes post-maturation fragmentation processing. This processing consists of site-specific cleavage that generates gapped, discontinuous rRNA molecules. However, the molecular mechanism underlying introduction of the gap structure (the 'hidden break') is poorly understood. Here, we found that the DEAD box protein RH39 plays a key role in introduction of the hidden break into the 23S rRNA in Arabidopsis chloroplasts. Genetic screening for an Arabidopsis plant with a drastically reduced level of ribulose-1,5-bisphosphate carboxylase/oxygenase identified an RH39 mutant. The levels of other chloroplast-encoded photosynthetic proteins were also severely reduced. The reductions were not due to a failure of transcription, but rather inefficiency in translation. RNA gel blotting revealed incomplete fragmentation of 23S rRNA in chloroplasts during maturation. In vitro analysis with recombinant RH39 suggested that the protein binds to the adjacent sequence upstream of the hidden break site to exert its function. We propose a molecular mechanism for the RH39-mediated fragmentation processing of 23S rRNA in chloroplasts.

  1. The ABCG transporter PEC1/ABCG32 is required for the formation of the developing leaf cuticle in Arabidopsis.

    Science.gov (United States)

    Fabre, Guillaume; Garroum, Imène; Mazurek, Sylwester; Daraspe, Jean; Mucciolo, Antonio; Sankar, Martial; Humbel, Bruno M; Nawrath, Christiane

    2016-01-01

    The cuticle is an essential diffusion barrier on aerial surfaces of land plants whose structural component is the polyester cutin. The PERMEABLE CUTICLE1/ABCG32 (PEC1) transporter is involved in plant cuticle formation in Arabidopsis. The gpat6 pec1 and gpat4 gapt8 pec1 double and triple mutants are characterized. Their PEC1-specific contributions to aliphatic cutin composition and cuticle formation during plant development are revealed by gas chromatography/mass spectrometry and Fourier-transform infrared spectroscopy. The composition of cutin changes during rosette leaf expansion in Arabidopsis. C16:0 monomers are in higher abundance in expanding than in fully expanded leaves. The atypical cutin monomer C18:2 dicarboxylic acid is more prominent in fully expanded leaves. Findings point to differences in the regulation of several pathways of cutin precursor synthesis. PEC1 plays an essential role during expansion of the rosette leaf cuticle. The reduction of C16 monomers in the pec1 mutant during leaf expansion is unlikely to cause permeability of the leaf cuticle because the gpat6 mutant with even fewer C16:0 monomers forms a functional rosette leaf cuticle at all stages of development. PEC1/ABCG32 transport activity affects cutin composition and cuticle structure in a specific and non-redundant fashion.

  2. Embryo splitting: a role in infertility?

    Science.gov (United States)

    Wood, C

    2001-01-01

    Embryo splitting may be used to increase the potential fertility of couples requiring IVF. Using cattle as a model, it is possible to increase pregnancy rates from 70% per transfer of good quality in-vivo-produced embryos, to 110% by transferring the two demi-embryos resulting from the bisection of one embryo. The 30-40% greater chance of conception would reduce costs for the government, health authorities and patients, and reduce stress, time and complications for women having IVF treatment. Embryo splitting may also provide donor embryos for infertile couples that cannot conceive naturally or with IVF. The shortage of children for adoption and donor embryos may be overcome by the production of demi-embryos.

  3. 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.

  4. Overexpression of PGA37/MYB118 and MYB115 promotes vegetative-to-embryonic transition in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xingchun Wang; Qi-Wen Niu; Chong Teng; Chao Li; Jinye Mu; Nam-Hai Chua; Jianru Zuo

    2009-01-01

    Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUSCHEL (WUS)/PLANT GROWTH ACTIVATOR6 (PGA6), BABY BOOM, LEAFY COTYLEDON1 (LEC1), and LEC2, is able to cause vegetative-to-embryonic transition or the formation of somatic embryos. Here, we report that a gain-offunction mutation in the Arabidopsis PGA37 gene, encoding the MYBI18 transcription factor, induced vegetative-toembryonic transition, the formation of somatic embryos from root explants, and an elevated LEC1 expression level.Double mutant analysis showed that WUS was not required for induction of somatic embryos by PGA37/MYB118.Iin addition, overexpression ofMYB115, a homolog of PGA37/MYB118, caused apga37-1ike phenotype. A mybll8 myb115 double mutant did not show apparent developmental abnormalities. Collectively, these results suggest that PGA37/MYB118 and MYB115 promote vegetative-to-embryonic transition, through a signaling pathway independent of WUS.

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

    Science.gov (United States)

    Li, Wei; Chiang, Yi-Hsuan; Coaker, Gitta

    2013-01-01

    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.

  6. POPCORN functions in the auxin pathway to regulate embryonic body plan and meristem organization in Arabidopsis.

    Science.gov (United States)

    Xiang, Daoquan; Yang, Hui; Venglat, Prakash; Cao, Yongguo; Wen, Rui; Ren, Maozhi; Stone, Sandra; Wang, Edwin; Wang, Hong; Xiao, Wei; Weijers, Dolf; Berleth, Thomas; Laux, Thomas; Selvaraj, Gopalan; Datla, Raju

    2011-12-01

    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 encodes a WD-40 protein expressed both during embryo development and postembryonically in the SAM and RAM. The two pcn alleles identified in this study are temperature sensitive, showing defective embryo development when grown at 22°C that is rescued when grown at 29°C. In pcn mutants, meristem-specific expression of WUSCHEL (WUS), CLAVATA3, and WUSCHEL-RELATED HOMEOBOX5 is not maintained; SHOOTMERISTEMLESS, BODENLOS (BDL) and MONOPTEROS (MP) are misexpressed. Several findings link PCN to auxin signaling and meristem function: ectopic expression of DR5(rev):green fluorescent protein (GFP), pBDL:BDL-GFP, and pMP:MP-β-glucuronidase in the meristem; altered polarity and expression of pPIN1:PIN1-GFP in the apical domain of the developing embryo; and resistance to auxin in the pcn mutants. The bdl mutation rescued embryo lethality of pcn, suggesting that improper auxin response is involved in pcn defects. Furthermore, WUS, PINFORMED1, PINOID, and TOPLESS are dosage sensitive in pcn, suggesting functional interaction. Together, our results suggest that PCN functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the SAM and RAM.

  7. Epidermal patterning genes are active during embryogenesis in Arabidopsis.

    Science.gov (United States)

    Costa, Silvia; Dolan, Liam

    2003-07-01

    Epidermal cells in the root of Arabidopsis seedling differentiate either as hair or non-hair cells, while in the hypocotyl they become either stomatal or elongated cells. WEREWOLF (WER) and GLABRA2 (GL2) are positive regulators of non-hair and elongated cell development. CAPRICE (CPC) is a positive regulator of hair cell development in the root. We show that WER, GL2 and CPC are expressed and active during the stages of embryogenesis when the pattern of cells in the epidermis of the root-hypocotyl axis forms. GL2 is first expressed in the future epidermis in the heart stage embryo and its expression is progressively restricted to those cells that will acquire a non-hair identity in the transition between torpedo and mature stage. The expression of GL2 at the heart stage requires WER function. WER and CPC are transiently expressed throughout the root epidermal layer in the torpedo stage embryo when the cell-specific pattern of GL2 expression is being established in the epidermis. We also show that WER positively regulates CPC transcription and GL2 negatively regulates WER transcription in the mature embryo. We propose that the restriction of GL2 to the future non-hair cells in the root epidermis can be correlated with the activities of WER and CPC during torpedo stage. In the embryonic hypocotyl we show that WER controls GL2 expression. We also provide evidence indicating that CPC may also regulate GL2 expression in the hypocotyl.

  8. 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.

  9. GONAD: A Novel CRISPR/Cas9 Genome Editing Method that Does Not Require Ex Vivo Handling of Embryos.

    Science.gov (United States)

    Gurumurthy, Channabasavaiah B; Takahashi, Gou; Wada, Kenta; Miura, Hiromi; Sato, Masahiro; Ohtsuka, Masato

    2016-01-01

    Transgenic technologies used for creating a desired genomic change in animals involve three critical steps: isolation of fertilized eggs, microinjection of transgenic DNA into them and their subsequent transfer to recipient females. These ex vivo steps have been widely used for over 3 decades and they were also readily adapted for the latest genome editing technologies such as ZFNs, TALENs, and CRISPR/Cas9 systems. We recently developed a method called GONAD (Genome editing via Oviductal Nucleic Acids Delivery) that does not require all the three critical steps of transgenesis and therefore relieves the bottlenecks of widely used animal transgenic technologies. Here we provide protocols for the GONAD system.

  10. 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.

  11. 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.

  12. Arabidopsis PTD is required for type I crossover formation and affects recombination frequency in two different chromosomal regions.

    Science.gov (United States)

    Lu, Pingli; Wijeratne, Asela J; Wang, Zhengjia; Copenhaver, Gregory P; Ma, Hong

    2014-03-20

    In eukaryotes, crossovers together with sister chromatid cohesion maintain physical association between homologous chromosomes, ensuring accurate chromosome segregation during meiosis I and resulting in exchange of genetic information between homologues. The Arabidopsis PTD (Parting Dancers) gene affects the level of meiotic crossover formation, but its functional relationships with other core meiotic genes, such as AtSPO11-1, AtRAD51, and AtMSH4, are unclear; whether PTD has other functions in meiosis is also unknown. To further analyze PTD function and to test for epistatic relationships, we compared the meiotic chromosome behaviors of Atspo11-1 ptd and Atrad51 ptd double mutants with the relevant single mutants. The results suggest that PTD functions downstream of AtSPO11-1 and AtRAD51 in the meiotic recombination pathway. Furthermore, we found that meiotic defects in rck ptd and Atmsh4 ptd double mutants showed similar meiotic phenotypes to those of the relevant single mutants, providing genetic evidences for roles of PTD and RCK in the type I crossovers pathway. Moreover, we employed a pollen tetrad-based fluorescence method and found that the meiotic crossover frequencies in two genetic intervals were significantly reduced from 6.63% and 22.26% in wild-type to 1.14% and 6.36%, respectively, in the ptd-2 mutant. These results revealed new aspects of PTD function in meiotic crossover formation.

  13. Arabidopsis COPPER MODIFIED RESISTANCE1/PATRONUS1 is essential for growth adaptation to stress and required for mitotic onset control.

    Science.gov (United States)

    Juraniec, Michal; Heyman, Jefri; Schubert, Veit; Salis, Pietrino; De Veylder, Lieven; Verbruggen, Nathalie

    2016-01-01

    The mitotic checkpoint (MC) guards faithful sister chromatid segregation by monitoring the attachment of spindle microtubules to the kinetochores. When chromosome attachment errors are detected, MC delays the metaphase-to-anaphase transition through the inhibition of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. In contrast to yeast and mammals, our knowledge on the proteins involved in MC in plants is scarce. Transient synchronization of root tips as well as promoter-reporter gene fusions were performed to analyze temporal and spatial expression of COPPER MODIFIED RESISTANCE1/PATRONUS1 (CMR1/PANS1) in developing Arabidopsis thaliana seedlings. Functional analysis of the gene was carried out, including CYCB1;2 stability in CMR1/PANS1 knockout and overexpressor background as well as metaphase-anaphase chromosome status. CMR1/PANS1 is transcriptionally active during M phase. Its deficiency provokes premature cell cycle exit and in consequence a rapid consumption of the number of meristematic cells in particular under stress conditions that are known to affect spindle microtubules. Root growth impairment is correlated with a failure to delay the onset of anaphase, resulting in anaphase bridges and chromosome missegregation. CMR1/PANS1 overexpression stabilizes the mitotic CYCB1;2 protein. Likely, CMR1/PANS1 coordinates mitotic cell cycle progression by acting as an APC/C inhibitor and plays a key role in growth adaptation to stress.

  14. 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.

  15. The chloroplast NifS-like protein of Arabidopsis thaliana is required for iron-sulfur cluster formation in ferredoxin.

    Science.gov (United States)

    Ye, Hong; Garifullina, Gulnara F; Abdel-Ghany, Salah E; Zhang, Lihong; Pilon-Smits, Elizabeth A H; Pilon, Marinus

    2005-02-01

    Plastids are known to be able to synthesize their own iron-sulfur clusters, but the biochemical machinery responsible for this process is not known. In this study it is investigated whether CpNifS, the chloroplastic NifS-like cysteine desulfurase of Arabidopsis thaliana (L.) Heynh. is responsible for the release of sulfur from cysteine for the biogenesis of iron-sulfur (Fe-S) clusters in chloroplasts. Using an in vitro reconstitution assay it was found that purified CpNifS was sufficient for Fe-S cluster formation in ferredoxin in the presence of cysteine and a ferrous iron salt. Antibody-depletion experiments using stromal extract showed that CpNifS is also essential for the Fe-S cluster formation activity of chloroplast stroma. The activity of CpNifS in the stroma was 50- to 80-fold higher than that of purified CpNifS on a per-protein basis, indicating that other stromal factors cooperate in Fe-S cluster formation. When stromal extract was separated on a gel-filtration column, most of the CpNifS eluted as a dimer of 86 kDa, but a minor fraction of the stromal CpNifS eluted at a molecular weight of approx. 600 kDa, suggesting the presence of a multi-protein complex. The possible nature of the interacting proteins is discussed.

  16. Rapid severing and motility of chloroplast-actin filaments are required for the chloroplast avoidance response in Arabidopsis.

    Science.gov (United States)

    Kong, Sam-Geun; Arai, Yoshiyuki; Suetsugu, Noriyuki; Yanagida, Toshio; Wada, Masamitsu

    2013-02-01

    Phototropins (phot1 and phot2 in Arabidopsis thaliana) relay blue light intensity information to the chloroplasts, which move toward weak light (the accumulation response) and away from strong light (the avoidance response). Chloroplast-actin (cp-actin) filaments are vital for mediating these chloroplast photorelocation movements. In this report, we examine in detail the cp-actin filament dynamics by which the chloroplast avoidance response is regulated. Although stochastic dynamics of cortical actin fragments are observed on the chloroplasts, the basic mechanisms underlying the disappearance (including severing and turnover) of the cp-actin filaments are regulated differently from those of cortical actin filaments. phot2 plays a pivotal role in the strong blue light-induced severing and random motility of cp-actin filaments, processes that are therefore essential for asymmetric cp-actin formation for the avoidance response. In addition, phot2 functions in the bundling of cp-actin filaments that is induced by dark incubation. By contrast, the function of phot1 is dispensable for these responses. Our findings suggest that phot2 is the primary photoreceptor involved in the rapid reorganization of cp-actin filaments that allows chloroplasts to change direction rapidly and control the velocity of the avoidance movement according to the light's intensity and position.

  17. 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.

  18. The Arabidopsis P4-ATPase ALA3 localizes to the golgi and requires a beta-subunit to function in lipid translocation and secretory vesicle formation.

    Science.gov (United States)

    Poulsen, Lisbeth Rosager; López-Marqués, Rosa Laura; McDowell, Stephen C; Okkeri, Juha; Licht, Dirk; Schulz, Alexander; Pomorski, Thomas; Harper, Jeffrey F; Palmgren, Michael Gjedde

    2008-03-01

    Vesicle budding in eukaryotes depends on the activity of lipid translocases (P(4)-ATPases) that have been implicated in generating lipid asymmetry between the two leaflets of the membrane and in inducing membrane curvature. We show that Aminophospholipid ATPase3 (ALA3), a member of the P(4)-ATPase subfamily in Arabidopsis thaliana, localizes to the Golgi apparatus and that mutations of ALA3 result in impaired growth of roots and shoots. The growth defect is accompanied by failure of the root cap to release border cells involved in the secretion of molecules required for efficient root interaction with the environment, and ala3 mutants are devoid of the characteristic trans-Golgi proliferation of slime vesicles containing polysaccharides and enzymes for secretion. In yeast complementation experiments, ALA3 function requires interaction with members of a novel family of plant membrane-bound proteins, ALIS1 to ALIS5 (for ALA-Interacting Subunit), and in this host ALA3 and ALIS1 show strong affinity for each other. In planta, ALIS1, like ALA3, localizes to Golgi-like structures and is expressed in root peripheral columella cells. We propose that the ALIS1 protein is a beta-subunit of ALA3 and that this protein complex forms an important part of the Golgi machinery required for secretory processes during plant development.

  19. DAPI Staining of Drosophila Embryos.

    Science.gov (United States)

    Rothwell, Wendy F; Sullivan, William

    2007-10-01

    INTRODUCTIONDrosophila embryos can be stained with specific fluorescent probes or antibodies through either direct or indirect immunofluorescence. In particular, several effective probes exist for visualizing DNA. 4',6-diamidino-2-phenylindole (DAPI) is a commonly used DNA-binding dye. Because it is specific for double-stranded DNA, no prior RNase treatment is required. While the embryo staining method described here uses DAPI, other fluorescent DNA probes can be processed similarly.

  20. Casein kinase II is required for proper cell division and acts as a negative regulator of centrosome duplication in Caenorhabditis elegans embryos

    Science.gov (United States)

    Medley, Jeffrey C.; Kabara, Megan M.; Stubenvoll, Michael D.; DeMeyer, Lauren E.

    2017-01-01

    ABSTRACT Centrosomes are the primary microtubule-organizing centers that orchestrate microtubule dynamics during the cell cycle. The correct number of centrosomes is pivotal for establishing bipolar mitotic spindles that ensure accurate segregation of chromosomes. Thus, centrioles must duplicate once per cell cycle, one daughter per mother centriole, the process of which requires highly coordinated actions among core factors and modulators. Protein phosphorylation is shown to regulate the stability, localization and activity of centrosome proteins. Here, we report the function of Casein kinase II (CK2) in early Caenorhabditis elegans embryos. The catalytic subunit (KIN-3/CK2α) of CK2 localizes to nuclei, centrosomes and midbodies. Inactivating CK2 leads to cell division defects, including chromosome missegregation, cytokinesis failure and aberrant centrosome behavior. Furthermore, depletion or inhibiting kinase activity of CK2 results in elevated ZYG-1 levels at centrosomes, restoring centrosome duplication and embryonic viability to zyg-1 mutants. Our data suggest that CK2 functions in cell division and negatively regulates centrosome duplication in a kinase-dependent manner. PMID:27881437

  1. 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.

  2. Chondroitin 4-O-sulfotransferases are required for cell adhesion and morphogenesis in the Ciona intestinalis embryo.

    Science.gov (United States)

    Nakamura, Jun; Tetsukawa, Akira; Fujiwara, Shigeki

    2015-01-01

    Chondroitin sulfate (CS) is a carbohydrate component of proteoglycans. Several types of sulfotransferases determine the pattern of CS sulfation, and thus regulate the biological functions of proteoglycans. The protochordate ascidians are the closest relatives of vertebrates, but the functions of their sulfotransferases have not been investigated. Here, we show that two chondroitin 4-O-sulfotransferases (C4STs) play important roles in the embryonic morphogenesis of the ascidian Ciona intestinalis. Ci-C4ST-like1 is predominantly expressed in the epidermis and muscle. Epidermal and muscle cells became spherical upon the injection of a Ci-C4ST-like1-specific morpholino oligo (MO), thus suggesting weakened cell adhesion. Co-injection of a Ci-C4ST-like1-expressing transgene rescued the phenotype, suggesting that the effects of the MO were specific. Ci-C4ST-like3 was expressed in the central nervous system, muscle, and mesenchyme. A specific MO appeared to affect cell adhesion in the epidermis and muscle. Convergent extension movement of notochordal cells was also impaired. Forced expression of Ci-C4ST-like3 restored normal morphogenesis, suggesting that the effects of the MO were specific. The present study suggests that Ci-C4ST-like1 and Ci-C4ST-like3 are required for cell adhesion mainly in the epidermis and muscle.

  3. MYB64 and MYB119 are required for cellularization and differentiation during female gametogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Rabiger, David S; Drews, Gary N

    2013-01-01

    In angiosperms, the egg cell forms within the multicellular, haploid female gametophyte. Female gametophyte and egg cell development occurs through a unique process in which a haploid spore initially undergoes several rounds of synchronous nuclear divisions without cytokinesis, resulting in a single cell containing multiple nuclei. The developing gametophyte then forms cell walls (cellularization) and the resulting cells differentiate to generate the egg cell and several accessory cells. The switch between free nuclear divisions and cellularization-differentiation occurs during developmental stage FG5 in Arabidopsis, and we refer to it as the FG5 transition. The molecular regulators that initiate the FG5 transition during female gametophyte development are unknown. In this study, we show using mutant analysis that two closely related MYB transcription factors, MYB64 and MYB119, act redundantly to promote this transition. MYB64 and MYB119 are expressed during the FG5 transition, and most myb64 myb119 double mutant gametophytes fail to initiate the FG5 transition, resulting in uncellularized gametophytes with supernumerary nuclei. Analysis of cell-specific markers in myb64 myb119 gametophytes that do cellularize suggests that gametophytic polarity and differentiation are also affected. We also show using multiple-mutant analysis that MYB119 expression is regulated by the histidine kinase CKI1, the primary activator of two-component signaling (TCS) during female gametophyte development. Our data establish a molecular pathway regulating the FG5 transition and implicates CKI1-dependent TCS in the promotion of cellularization, differentiation, and gamete specification during female gametogenesis.

  4. MYB64 and MYB119 are required for cellularization and differentiation during female gametogenesis in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    David S Rabiger

    Full Text Available In angiosperms, the egg cell forms within the multicellular, haploid female gametophyte. Female gametophyte and egg cell development occurs through a unique process in which a haploid spore initially undergoes several rounds of synchronous nuclear divisions without cytokinesis, resulting in a single cell containing multiple nuclei. The developing gametophyte then forms cell walls (cellularization and the resulting cells differentiate to generate the egg cell and several accessory cells. The switch between free nuclear divisions and cellularization-differentiation occurs during developmental stage FG5 in Arabidopsis, and we refer to it as the FG5 transition. The molecular regulators that initiate the FG5 transition during female gametophyte development are unknown. In this study, we show using mutant analysis that two closely related MYB transcription factors, MYB64 and MYB119, act redundantly to promote this transition. MYB64 and MYB119 are expressed during the FG5 transition, and most myb64 myb119 double mutant gametophytes fail to initiate the FG5 transition, resulting in uncellularized gametophytes with supernumerary nuclei. Analysis of cell-specific markers in myb64 myb119 gametophytes that do cellularize suggests that gametophytic polarity and differentiation are also affected. We also show using multiple-mutant analysis that MYB119 expression is regulated by the histidine kinase CKI1, the primary activator of two-component signaling (TCS during female gametophyte development. Our data establish a molecular pathway regulating the FG5 transition and implicates CKI1-dependent TCS in the promotion of cellularization, differentiation, and gamete specification during female gametogenesis.

  5. 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.

  6. A Pre-mRNA-splicing factor is required for RNA-directed DNA methylation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Chao-Feng Huang

    Full Text Available Cytosine DNA methylation is a stable epigenetic mark that is frequently associated with the silencing of genes and transposable elements (TEs. In Arabidopsis, the establishment of DNA methylation is through the RNA-directed DNA methylation (RdDM pathway. Here, we report the identification and characterization of RDM16, a new factor in the RdDM pathway. Mutation of RDM16 reduced the DNA methylation levels and partially released the silencing of a reporter gene as well as some endogenous genomic loci in the DNA demethylase ros1-1 mutant background. The rdm16 mutant had morphological defects and was hypersensitive to salt stress and abscisic acid (ABA. Map-based cloning and complementation test led to the identification of RDM16, which encodes a pre-mRNA-splicing factor 3, a component of the U4/U6 snRNP. RNA-seq analysis showed that 308 intron retention events occurred in rdm16, confirming that RDM16 is involved in pre-mRNA splicing in planta. RNA-seq and mRNA expression analysis also revealed that the RDM16 mutation did not affect the pre-mRNA splicing of known RdDM genes, suggesting that RDM16 might be directly involved in RdDM. Small RNA expression analysis on loci showing RDM16-dependent DNA methylation suggested that unlike the previously reported putative splicing factor mutants, rdm16 did not affect small RNA levels; instead, the rdm16 mutation caused a decrease in the levels of Pol V transcripts. ChIP assays revealed that RDM16 was enriched at some Pol V target loci. Our results suggest that RDM16 regulates DNA methylation through influencing Pol V transcript levels. Finally, our genome-wide DNA methylation analysis indicated that RDM16 regulates the overall methylation of TEs and gene-surrounding regions, and preferentially targets Pol IV-dependent DNA methylation loci and the ROS1 target loci. Our work thus contributes to the understanding of RdDM and its interactions with active DNA demethylation.

  7. The Carboxy-terminus of BAK1 regulates kinase activity and is required for normal growth of Arabidopsis

    Directory of Open Access Journals (Sweden)

    Man-Ho eOh

    2014-02-01

    Full Text Available Binding of brassinolide to the BRASSINOSTEROID-INSENSTIVE 1 (BRI1 receptor kinase promotes interaction with its co-receptor, BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1. Juxtaposition of the kinase domains that occurs then allows reciprocal transphosphorylation and activation of both kinases, but details of that process are not entirely clear. In the present study we show that the carboxy (C - terminal polypeptide of BAK1 may play a role. First, we demonstrate that the C-terminal domain is a strong inhibitor of the transphosphorylation activity of the recombinant BAK1 cytoplasmic domain protein. However, recombinant BAK1 lacking the C-terminal domain is unable to transactivate the peptide kinase activity of BRI1 in vitro. Thus, the C-terminal domain may play both a positive and negative role. Interestingly, a synthetic peptide corresponding to the full C-terminal domain (residues 576 to 615 of BAK1 interacted with recombinant BRI1 in vitro, and that interaction was enhanced by phosphorylation at the Tyr-610 site. Expression of a BAK1 C-terminal domain truncation (designated BAK1-ΔCT-Flag in transgenic Arabidopsis plants lacking endogenous bak1 and its functional paralog, bkk1, produced plants that were wild type in appearance but much smaller than plants expressing full-length BAK1-Flag. The reduction in growth may be attributed to a partial inhibition of BR signaling in vivo as reflected in root growth assays but other factors are likely involved as well. Our working model is that in vivo, the inhibitory action of the C-terminal domain of BAK1 is relieved by binding to BRI1. However, that interaction is not essential for BR signaling, but other aspects of cellular signaling are impacted when the C-terminal domain is truncated and result in inhibition of growth. These results increase the molecular understanding of the C-terminal domain of BAK1 as a regulator of kinase activity that may serve as a model for other receptor kinases.

  8. Truncation of LEAFY COTYLEDON1 protein is required for asexual reproduction in Kalanchoë daigremontiana.

    Science.gov (United States)

    Garcês, Helena M P; Koenig, Daniel; Townsley, Brad T; Kim, Minsung; Sinha, Neelima R

    2014-05-01

    Kalanchoë daigremontiana reproduces asexually by generating numerous plantlets on its leaf margins. The formation of plantlets requires the somatic initiation of organogenic and embryogenic developmental programs in the leaves. However, unlike normal embryogenesis in seeds, leaf somatic embryogenesis bypasses seed dormancy to form viable plantlets. In Arabidopsis (Arabidopsis thaliana), seed dormancy and embryogenesis are initiated by the transcription factor LEAFY COTYLEDON1 (LEC1). The K. daigremontiana ortholog of LEC1 is expressed during leaf somatic embryo development. However, KdLEC1 encodes for a LEC1-type protein that has a unique B domain, with 11 unique amino acids and a premature stop codon. Moreover, the truncated KdLEC1 protein is not functional in Arabidopsis. Here, we show that K. daigremontiana transgenic plants expressing a functional, chimeric KdLEC1 gene under the control of Arabidopsis LEC1 promoter caused several developmental defects to leaf somatic embryos, including seed dormancy characteristics. The dormant plantlets also behaved as typical dormant seeds. Transgenic plantlets accumulated oil bodies and responded to the abscisic acid biosynthesis inhibitor fluridone, which broke somatic-embryo dormancy and promoted their normal development. Our results indicate that having a mutated form of LEC1 gene in K. daigremontiana is essential to bypass dormancy in the leaf embryos and generate viable plantlets, suggesting that the loss of a functional LEC1 promotes viviparous leaf somatic embryos and thus enhances vegetative propagation in K. daigremontiana. Mutations resulting in truncated LEC1 proteins may have been of a selective advantage in creating somatic propagules, because such mutations occurred independently in several Kalanchoë species, which form plantlets constitutively.

  9. Reference: 635 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available egan E et al. 2007 Jul. Plant Cell 19(7):2246-63. Embryogenesis in Arabidopsis thaliana is marked by a predi...ctable sequence of oriented cell divisions, which precede cell fate determination. We show that mutation of ...the TORMOZ (TOZ) gene yields embryos with aberrant cell division planes and arres...ted embryos that appear not to have established normal patterning. The defects in toz mutants differ from pre...viously described mutations that affect embryonic cell division patterns. Longitudinal division planes of the proembryo are fre

  10. Reference: 724 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available is required in the roots during early signaling steps of rhizobacteria-mediated ...ISR. MYB72 is required in early signaling steps of rhizobacteria-induced systemic resistance in Arabidopsis.

  11. Third Party Reproduction: Sperm, Egg, and Embryo Donation and Surrogacy

    Science.gov (United States)

    ... third-party reproduction” refers to the use of eggs , sperm , or embryos that have been donated by a ... the requisite screening and testing required of all egg and sperm donors. For embryos that are created specifically for ...

  12. 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.

  13. Downy mildew (Peronospora parasitica) resistance genes in Arabidopsis vary in functional requirements for NDR1, EDS1, NPR1 and salicylic acid accumulation.

    Science.gov (United States)

    McDowell, J M; Cuzick, A; Can, C; Beynon, J; Dangl, J L; Holub, E B

    2000-06-01

    To better understand the genetic requirements for R gene-dependent defense activation in Arabidopsis, we tested the effect of several defense response mutants on resistance specified by eight RPP genes (for resistance to Peronospora parasitica) expressed in the Col-0 background. In most cases, resistance was not suppressed by a mutation in the SAR regulatory gene NPR1 or by expression of the NahG transgene. Thus, salicylic acid accumulation and NPR1 function are not necessary for resistance mediated by these RPP genes. In addition, resistance conferred by two of these genes, RPP7 and RPP8, was not significantly suppressed by mutations in either EDS1 or NDR1. RPP7 resistance was also not compromised by mutations in EIN2, JAR1 or COI1 which affect ethylene or jasmonic acid signaling. Double mutants were therefore tested. RPP7 and RPP8 were weakly suppressed in an eds1-2/ndr1-1 background, suggesting that these RPP genes operate additively through EDS1, NDR1 and as-yet-undefined signaling components. RPP7 was not compromised in coi1/npr1 or coi1/NahG backgrounds. These observations suggest that RPP7 initiates resistance through a novel signaling pathway that functions independently of salicylic acid accumulation or jasmonic acid response components.

  14. Requirement for pectin methyl esterase and preference for fragmented over native pectins for wall-associated kinase-activated, EDS1/PAD4-dependent stress response in Arabidopsis.

    Science.gov (United States)

    Kohorn, Bruce D; Kohorn, Susan L; Saba, Nicholas J; Martinez, Victoriano Meco

    2014-07-01

    The wall-associated kinases (WAKs) have a cytoplasmic protein kinase domain that spans the plasma membrane and binds pectin in the extracellular matrix of plants. WAKs are required for cell expansion during Arabidopsis seedling development but are also an integral part of the response to pathogens and stress that present oligogalacturonides (OGs), which subsequently bind to WAKs and activate a MPK6 (mitogen-activated protein kinase)-dependent pathway. It was unclear how WAKs distinguish native pectin polymers and OGs to activate one or the other of these two pathways. A dominant allele of WAK2 constitutively activates the stress response, and we show here that the effect is dependent upon EDS1 and PAD4, transcriptional activators involved in the pathogen response. Moreover, the WAK2 dominant allele is suppressed by a null allele of a pectin methyl esterase (PME3) whose activity normally leads to cross-linking of pectins in the cell wall. Although OGs activate a transcriptional response in wild type, the response is enhanced in a pme3/pme3 null, consistent with a competition by OG and native polymers for activation of WAKs. This provides a plausible mechanism for WAKs to distinguish an expansion from a stress pathway.

  15. A chaperone function of NO CATALASE ACTIVITY1 is required to maintain catalase activity and for multiple stress responses in Arabidopsis.

    Science.gov (United States)

    Li, Jing; Liu, Juntao; Wang, Guoqiang; Cha, Joon-Yung; Li, Guannan; Chen, She; Li, Zhen; Guo, Jinghua; Zhang, Caiguo; Yang, Yongqing; Kim, Woe-Yeon; Yun, Dae-Jin; Schumaker, Karen S; Chen, Zhongzhou; Guo, Yan

    2015-03-01

    Catalases are key regulators of reactive oxygen species homeostasis in plant cells. However, the regulation of catalase activity is not well understood. In this study, we isolated an Arabidopsis thaliana mutant, no catalase activity1-3 (nca1-3) that is hypersensitive to many abiotic stress treatments. The mutated gene was identified by map-based cloning as NCA1, which encodes a protein containing an N-terminal RING-finger domain and a C-terminal tetratricopeptide repeat-like helical domain. NCA1 interacts with and increases catalase activity maximally in a 240-kD complex in planta. In vitro, NCA1 interacts with CATALASE2 (CAT2) in a 1:1 molar ratio, and the NCA1 C terminus is essential for this interaction. CAT2 activity increased 10-fold in the presence of NCA1, and zinc ion binding of the NCA1 N terminus is required for this increase. NCA1 has chaperone protein activity that may maintain the folding of catalase in a functional state. NCA1 is a cytosol-located protein. Expression of NCA1 in the mitochondrion of the nca1-3 mutant does not rescue the abiotic stress phenotypes of the mutant, while expression in the cytosol or peroxisome does. Our results suggest that NCA1 is essential for catalase activity.

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

    Science.gov (United States)

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

    1998-06-01

    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 between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.

  17. MIRO1 influences the morphology and intracellular distribution of mitochondria during embryonic cell division in Arabidopsis.

    Science.gov (United States)

    Yamaoka, Shohei; Nakajima, Masaki; Fujimoto, Masaru; Tsutsumi, Nobuhiro

    2011-02-01

    Regulating the morphology and intracellular distribution of mitochondria is essential for embryo development in animals. However, the importance of such regulation is not clearly defined in plants. The evolutionarily conserved Miro proteins are known to be involved in the regulation of mitochondrial morphology and motility. We previously demonstrated that MIRO1, an Arabidopsis thaliana orthologue of the Miro protein, is required for embryogenesis. An insertional mutation in the MIRO1 gene causes arrest of embryonic cell division, leading to abortion of the embryo at an early stage. Here we investigated the role of MIRO1 in the regulation of mitochondrial behaviour in egg cells and early-stage embryos using GFP-labeled mitochondria. Two-photon laser scanning microscopy revealed that, in miro1 mutant egg cells, mitochondria are abnormally enlarged, although egg cell formation is nearly unaffected. After fertilization and subsequent zygotic cell division, the homozygous miro1 mutant two-celled embryo contained a significantly reduced number of mitochondria in its apical cell compared with the wild type, suggesting that the miro1 mutation inhibits proper intracellular distribution of mitochondria, leading to an arrest of embryonic cell division. Our findings suggest that proper mitochondrial morphology and intracellular distribution are maintained by MIRO1 and are vital for embryonic cell division.

  18. Embryo donation in Iran: an ethical review.

    Science.gov (United States)

    Afshar, Leila; Bagheri, Alireza

    2013-12-01

    Iran is the only Muslim country that has legislation on embryo donation, adopted in 2003. With an estimated 10-15% of couples in the country that are infertile, there are not any legal or religious barriers that prohibit an infertile couple from taking advantage of Assisted Reproductive Technologies (ARTs). Although all forms of ARTs available in Iran have been legitimized by religious authorities, there is a lack of legislation in all ARTs except embryo donation. By highlighting ethical issues in embryo donation, the paper presents a critical review of the Act of Embryo Donation in Iran. The paper argues that the Act does not provide enough safeguards for the future child and assurance for the safety of the donated embryos. It also does not restrict embryo donation to surplus embryos from infertile couples and is silent about the number of embryos that could be donated by each couple as well as the number of recipients for donated embryos by a couple. The Act is also silent about the issues of genetic linkage (nasab) and heritage which are challenging issues, especially in a conservative Islamic society. As a result, the future child may not inherit from their birth parents, as it is not required by the Act, or from the genetically related parents under the anonymity policy. Finally there is no standard national protocol or guidelines to evaluate the safety of the donated embryos. The paper concludes that despite its benefits, the Act lacks clarity, and it is subject to misunderstanding and confusion.

  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.

  20. Arabidopsis inositol pentakisphosphate 2-kinase, AtIPK1, is required for growth and modulates phosphate homeostasis at the transcriptional level.

    Science.gov (United States)

    Kuo, Hui-Fen; Chang, Tzu-Yun; Chiang, Su-Fen; Wang, Wei-Di; Charng, Yee-Yung; Chiou, Tzyy-Jen

    2014-11-01

    Inositol hexakisphosphate (IP6 ) provides a phosphorous reservoir in plant seeds; in addition, along with its biosynthesis intermediates and derivatives, IP6 also plays important roles in diverse developmental and physiological processes. Disruption of the Arabidopsis inositol pentakisphosphate 2-kinase coding gene AtIPK1 was previously shown to reduce IP6 content in vegetative tissues and affect phosphate (Pi) sensing. Here we show that AtIPK1 is required for sustaining plant growth, as null mutants are non-viable. An incomplete loss-of-function mutant, atipk1-1, exhibited disturbed Pi homeostasis and overaccumulated Pi as a consequence of increased Pi uptake activity and root-to-shoot Pi translocation. The atipk1-1 mutants also showed a Pi deficiency-like root system architecture with reduced primary root and enhanced lateral root growth. Transcriptome analysis indicated that a subset of Pi starvation-responsive genes was transcriptionally perturbed in the atipk1-1 mutants and the expression of multiple genes involved in Pi uptake, allocation, and remobilization was increased. Genetic and transcriptional analyses suggest that disturbance of Pi homeostasis caused by atipk1 mutation involved components in addition to PHR1(-like) transcription factors. Notably, the transcriptional increase of a number of Pi starvation-responsive genes in the atipk1-1 mutants is correlated with the reduction of histone variant H2A.Z occupation in chromatin. The myo-inositol-1-phosphate synthase mutants, atmips1 and atmips2 with comparable reduction in vegetative IP6 to that in the atipk1-1 mutants did not overaccumulate Pi, suggesting that Pi homeostasis modulated by AtIPK1 is not solely attributable to IP6 level. This study reveals that AtIPK1 has important roles in growth and Pi homeostasis.

  1. Arabidopsis MKS1 is involved in basal immunity and requires an intact N-terminal domain for proper function.

    Directory of Open Access Journals (Sweden)

    Klaus Petersen

    Full Text Available BACKGROUND: Innate immune signaling pathways in animals and plants are regulated by mitogen-activated protein kinase (MAPK cascades. MAP kinase 4 (MPK4 functions downstream of innate immune receptors via a nuclear substrate MKS1 to regulate the activity of the WRKY33 transcription factor, which in turn controls the production of anti-microbial phytoalexins. METHODOLOGY/PRINCIPAL FINDINGS: We investigate the role of MKS1 in basal resistance and the importance of its N- and C-terminal domains for MKS1 function. We used the information that mks1 loss-of-function partially suppresses the mpk4 loss-of-function phenotype, and that transgenic expression of functional MKS1 in mpk4/mks1 double mutants reverted the mpk4 dwarf phenotype. Transformation of mks1/mpk4 with mutant versions of MKS1 constructs showed that a single amino acid substitution in a putative MAP kinase docking domain, MKS1-L32A, or a truncated MKS1 version unable to interact with WRKY33, were deficient in reverting the double mutant to the mpk4 phenotype. These results demonstrate functional requirement in MKS1 for the interaction with MPK4 and WRKY33. In addition, nuclear localization of MKS1 was shown to depend on an intact N-terminal domain. Furthermore, loss-of-function mks1 mutants exhibited increased susceptibility to strains of Pseudomonas syringae and Hyaloperonospora arabidopsidis, indicating that MKS1 plays a role in basal defense responses. CONCLUSIONS: Taken together, our results indicate that MKS1 function and subcellular location requires an intact N-terminus important for both MPK4 and WRKY33 interactions.

  2. Reference: 446 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available rk E et al. 2006 Nov. Plant Physiol. 142(3):1004-13. Arabidopsis (Arabidopsis thaliana) QUARTET (QRT) genes are require...d for pollen separation during normal floral development. In qrt mutants, the four products of microsporogenesis re...main fused and pollen grains are released as tetrads. In Arabid...opsis, tetrad analysis in qrt mutants has been used to map all five centromeres, easily distinguish sporophy...tic from gametophytic mutations, and accurately assess crossover interference. Using a combination of forward and re

  3. Reference: 796 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ceedings of the National Academy of Sciences of the United States of America DeBolt...required for normal microtubule dynamics and organization in Arabidopsis. 46 18064-9 19004800 2008 Nov Pro

  4. The TRANSPARENT TESTA12 gene of Arabidopsis encodes a multidrug secondary transporter-like protein required for flavonoid sequestration of the seed coat endothelium

    NARCIS (Netherlands)

    Debeaujon, I.; Peeters, A.J.M.; Leon-Kloosterziel, K.M.; Koornneef, M.

    2001-01-01

    Phenolic compounds that are present in the testa interfere with the physiology of seed dormancy and germination. We isolated a recessive Arabidopsis mutant with pale brown seeds, transparent testa12 (tt12), from a reduced seed dormancy screen. Microscopic analysis of tt12 developing and mature testa

  5. A simple and rapid flow cytometry-based assay to identify a competent embryo prior to embryo transfer

    OpenAIRE

    Pallinger, Eva; Bognar, Zoltan; Bodis, Jozsef; Csabai, Timea; Farkas, Nelli; Godony, Krisztina; Varnagy, Akos; Buzas, Edit; Szekeres-Bartho, Julia

    2017-01-01

    Multiple pregnancy is a risk for prematurity and preterm birth. The goal of assisted reproduction is to achieve a single pregnancy, by transferring a single embryo. This requires improved methods to identify the competent embryo. Here, we describe such a test, based on flow cytometric determination of the nucleic acid (PI+) containing extracellular vesicle (EV) count in day 5 embryo culture media. 88 women undergoing IVF were included in the study. More than 1 embryos were transferred to most...

  6. Arabidopsis thaliana Somatic Embryogenesis Receptor Kinase I protein is present in sporophytic and gametophytic cells and undergoes endocytosis

    NARCIS (Netherlands)

    Kwaaitaal, M.A.C.J.; Vries, de S.C.; Russinova, E.T.

    2005-01-01

    Arabidopsis thaliana plants expressing AtSERK1 fused to yellow-fluorescent protein were generated. Fluorescence was detected predominantly at the cell periphery, most likely the plasma membrane, of cells in ovules, embryo sacs, anthers, and embryos and in seedlings. The AtSERK1 protein was detected

  7. Redox regulation of ascorbate and glutathione by a chloroplastic dehydroascorbate reductase is required for high-light stress tolerance in Arabidopsis.

    Science.gov (United States)

    Noshi, Masahiro; Hatanaka, Risa; Tanabe, Noriaki; Terai, Yusuke; Maruta, Takanori; Shigeoka, Shigeru

    2016-05-01

    Chloroplasts are a significant site for reactive oxygen species production under illumination and, thus, possess a well-organized antioxidant system involving ascorbate. Ascorbate recycling occurs in different manners in this system, including a dehydroascorbate reductase (DHAR) reaction. We herein investigated the physiological significance of DHAR3 in photo-oxidative stress tolerance in Arabidopsis. GFP-fused DHAR3 protein was targeted to chloroplasts in Arabidopsis leaves. A DHAR3 knockout mutant exhibited sensitivity to high light (HL). Under HL, the ascorbate redox states were similar in mutant and wild-type plants, while total ascorbate content was significantly lower in the mutant, suggesting that DHAR3 contributes, at least to some extent, to ascorbate recycling. Activation of monodehydroascorbate reductase occurred in dhar3 mutant, which might compensate for the lack of DHAR3. Interestingly, glutathione oxidation was consistently inhibited in dhar3 mutant. These findings indicate that DHAR3 regulates both ascorbate and glutathione redox states to acclimate to HL.

  8. Characterization of an Arabidopsis-Phytophthora pathosystem: resistance requires a functional PAD2 gene and is independent of salicylic acid, ethylene and jasmonic acid signalling.

    Science.gov (United States)

    Roetschi, A; Si-Ammour, A; Belbahri, L; Mauch, F; Mauch-Mani, B

    2001-11-01

    Arabidopsis accessions were screened with isolates of Phytophthora porri originally isolated from other crucifer species. The described Arabidopsis-Phytophthora pathosystem shows the characteristics of a facultative biotrophic interaction similar to that seen in agronomically important diseases caused by Phytophthora species. In susceptible accessions, extensive colonization of the host tissue occurred and sexual and asexual spores were formed. In incompatible combinations, the plants reacted with a hypersensitive response (HR) and the formation of papillae at the sites of attempted penetration. Defence pathway mutants such as jar1 (jasmonic acid-insensitive), etr1 (ethylene receptor mutant) and ein2 (ethylene-insensitive) remained resistant towards P. porri. However, pad2, a mutant with reduced production of the phytoalexin camalexin, was hyper-susceptible. The accumulation of salicylic acid (SA) and PR1 protein was strongly reduced in pad2. Surprisingly, this lack of SA accumulation does not appear to be the cause of the hyper-susceptibility because interference with SA signalling in nahG plants or sid2 or npr1 mutants had only a minor effect on resistance. In addition, the functional SA analogue benzothiadiazol (BTH) did not induce resistance in susceptible plants including pad2. Similarly, the complete blockage of camalexin biosynthesis in pad3 did not cause susceptibility. Resistance of Arabidopsis against P. porri appears to depend on unknown defence mechanisms that are under the control of PAD2.

  9. 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.

  10. A Putative Chloroplast-Localized Ca(2+)/H(+) Antiporter CCHA1 Is Involved in Calcium and pH Homeostasis and Required for PSII Function in Arabidopsis.

    Science.gov (United States)

    Wang, Chao; Xu, Weitao; Jin, Honglei; Zhang, Taijie; Lai, Jianbin; Zhou, Xuan; Zhang, Shengchun; Liu, Shengjie; Duan, Xuewu; Wang, Hongbin; Peng, Changlian; Yang, Chengwei

    2016-08-01

    Calcium is important for chloroplast, not only in its photosynthetic but also nonphotosynthetic functions. Multiple Ca(2+)/H(+) transporters and channels have been described and studied in the plasma membrane and organelle membranes of plant cells; however, the molecular identity and physiological roles of chloroplast Ca(2+)/H(+) antiporters have remained unknown. Here we report the identification and characterization of a member of the UPF0016 family, CCHA1 (a chloroplast-localized potential Ca(2+)/H(+) antiporter), in Arabidopsis thaliana. We observed that the ccha1 mutant plants developed pale green leaves and showed severely stunted growth along with impaired photosystem II (PSII) function. CCHA1 localizes to the chloroplasts, and the levels of the PSII core subunits and the oxygen-evolving complex were significantly decreased in the ccha1 mutants compared with the wild type. In high Ca(2+) concentrations, Arabidopsis CCHA1 partially rescued the growth defect of yeast gdt1Δ null mutant, which is defective in a Ca(2+)/H(+) antiporter. The ccha1 mutant plants also showed significant sensitivity to high concentrations of CaCl2 and MnCl2, as well as variation in pH. Taken these results together, we propose that CCHA1 might encode a putative chloroplast-localized Ca(2+)/H(+) antiporter with critical functions in the regulation of PSII and in chloroplast Ca(2+) and pH homeostasis in Arabidopsis.

  11. The S8 serine, C1A cysteine and A1 aspartic protease families in Arabidopsis.

    Science.gov (United States)

    Beers, Eric P; Jones, Alan M; Dickerman, Allan W

    2004-01-01

    The Arabidopsis thaliana genome has over 550 protease sequences representing all five catalytic types: serine, cysteine, aspartic acid, metallo and threonine (MEROPS peptidase database, http://merops.sanger.ac.uk/), which probably reflect a wide variety of as yet unidentified functions performed by plant proteases. Recent indications that the 26S proteasome, a T1 family-threonine protease, is a regulator of light and hormone responsive signal transduction highlight the potential of proteases to participate in many aspects of plant growth and development. Recent discoveries that proteases are required for stomatal distribution, embryo development and disease resistance point to wider roles for four additional multigene families that include some of the most frequently studied (yet poorly understood) plant proteases: the subtilisin-like, serine proteases (family S8), the papain-like, cysteine proteases (family C1A), the pepsin-like, aspartic proteases (family A1) and the plant matrixin, metalloproteases (family M10A). In this report, 54 subtilisin-like, 30 papain-like and 59 pepsin-like proteases from Arabidopsis, are compared with S8, C1A and A1 proteases known from other plant species at the functional, phylogenetic and gene structure levels. Examples of structural conservation between S8, C1A and A1 genes from rice, barley, tomato and soybean and those from Arabidopsis are noted, indicating that some common, essential plant protease roles were established before the divergence of monocots and eudicots. Numerous examples of tandem duplications of protease genes and evidence for a variety of restricted expression patterns suggest that a high degree of specialization exists among proteases within each family. We propose that comprehensive analysis of the functions of these genes in Arabidopsis will firmly establish serine, cysteine and aspartic proteases as regulators and effectors of a wide range of plant processes.

  12. Undernutrition affects embryo quality of superovulated ewes.

    Science.gov (United States)

    Abecia, J A; Forcada, F; Palacín, I; Sánchez-Prieto, L; Sosa, C; Fernández-Foren, A; Meikle, A

    2015-02-01

    To determine the effect of undernutrition on embryo production and quality in superovulated sheep, 45 ewes were allocated into two groups to be fed diets that provided 1.5 (control, C; n = 20) or 0.5 (low nutrition, L; n = 25) times daily requirements for maintenance, from oestrous synchronization with intravaginal sponges to embryo collection. Embryos were collected 7 days after the onset of oestrus (day 0). Low nutrition resulted in lower live weight and body condition at embryo collection (P < 0.05). Diet (P < 0.01) and day of sampling (P < 0.001) significantly affected plasma non-esterified fatty acid (NEFA) and insulin concentrations. Plasma leptin concentrations decreased on day 7 only in L ewes. A significant effect of dietary treatment (P < 0.05) and day (P < 0.0001) was observed on plasma insulin-like growth factor (IGF)-I concentrations. The number of recovered oocytes and embryos did not differ between the groups (L: 15.4 ± 0.4; C: 12.4 ± 0.4). Recovery rate was lower (P < 0.05) in the L (60%) than in the C group (73%). The total number of embryos and number of viable-transferable embryos (5.0 ± 0.3 and 3.4 ± 0.3 embryos, respectively) of the L group were lower (P < 0.1) when compared with controls (8.4 ± 0.4 and 6.2 ± 0.4 embryos, respectively). Undernutrition during the period of superovulation and early embryonic development reduced total and viable number of embryos. These effects might be mediated by disruption of endocrine homeostasis, oviduct environment and/or oocyte quality.

  13. Reference: 221 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ell cycle. In addition, RAD51 is required for meiosis and its Arabidopsis (Arabidopsis thaliana) ortholog is important... cell cultures, the RAD51 paralog RAD51C is also important for mitotic homologous...ortant for recombination and DNA repair in the mitotic c...chromosome (homolog) pairing, synapsis, and recombination. The budding yeast (Saccharomyces cerevisiae) RAD51 gene is known to be imp

  14. Perception of the novel MAMP eMax from different Xanthomonas species requires the Arabidopsis receptor-like protein ReMAX and the receptor kinase SOBIR

    OpenAIRE

    Jehle, Anna Kristina; Fürst, Ursula; Lipschis, Martin; Albert, Markus; Felix, Georg

    2013-01-01

    As part of their innate immune system plants carry a number of pattern recognition receptors (PRRs) that can detect a broad range of microbe-associated molecular patterns (MAMPs). In a recently published article1 we described a novel, proteinaceous MAMP termed eMax (enigmatic MAMP of Xanthomonas) that derives from Xanthomonas and gets recognized by the receptor-like protein ReMAX (RECEPTOR OF eMax) of Arabidopsis thaliana. ReMAX has no ortholog in Nicotiana benthamiana and this species does n...

  15. The seed composition of Arabidopsis mutants for the group 3 sulfate transporters indicates a role in sulfate translocation within developing seeds.

    Science.gov (United States)

    Zuber, Hélène; Davidian, Jean-Claude; Aubert, Grégoire; Aimé, Delphine; Belghazi, Maya; Lugan, Raphaël; Heintz, Dimitri; Wirtz, Markus; Hell, Rüdiger; Thompson, Richard; Gallardo, Karine

    2010-10-01

    Sulfate is required for the synthesis of sulfur-containing amino acids and numerous other compounds essential for the plant life cycle. The delivery of sulfate to seeds and its translocation between seed tissues is likely to require specific transporters. In Arabidopsis (Arabidopsis thaliana), the group 3 plasmalemma-predicted sulfate transporters (SULTR3) comprise five genes, all expressed in developing seeds, especially in the tissues surrounding the embryo. Here, we show that sulfur supply to seeds is unaffected by T-DNA insertions in the SULTR3 genes. However, remarkably, an increased accumulation of sulfate was found in mature seeds of four mutants out of five. In these mutant seeds, the ratio of sulfur in sulfate form versus total sulfur was significantly increased, accompanied by a reduction in free cysteine content, which varied depending on the gene inactivated. These results demonstrate a reduced capacity of the mutant seeds to metabolize sulfate and suggest that these transporters may be involved in sulfate translocation between seed compartments. This was further supported by sulfate measurements of the envelopes separated from the embryo of the sultr3;2 mutant seeds, which showed differences in sulfate partitioning compared with the wild type. A dissection of the seed proteome of the sultr3 mutants revealed protein changes characteristic of a sulfur-stress response, supporting a role for these transporters in providing sulfate to the embryo. The mutants were affected in 12S globulin accumulation, demonstrating the importance of intraseed sulfate transport for the synthesis and maturation of embryo proteins. Metabolic adjustments were also revealed, some of which could release sulfur from glucosinolates.

  16. The Arabidopsis thaliana aleurone layer responds to nitric oxide, gibberellin, and abscisic acid and is sufficient and necessary for seed dormancy

    Science.gov (United States)

    Seed dormancy is a common phase of the plant life cycle and several parts of the seed can contribute to dormancy. Whole seeds, seeds lacking the testa, embryos, and isolated aleurone layers of Arabidopsis thaliana were used in experiments designed to identify components of the arabidopsis seed that ...

  17. 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.

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

    Science.gov (United States)

    Smit, Margot E; Weijers, Dolf

    2015-12-01

    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 mechanisms interact to generate local auxin accumulation in the early embryo. New auxin-dependent reporters help identifying these sites, while atomic structures of transcriptional response mediators help explain the diverse outputs of auxin signaling. Key auxin outputs are control of cell identity and cell division orientation, and progress has been made towards understanding the cellular basis of each. Importantly, a number of studies have combined computational modeling and experiments to analyze the developmental role, genetic circuitry and molecular mechanisms of auxin-dependent cell division control.

  19. Reference: 13 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available iluz G et al. 2002 Nov. Plant Cell 14(11):2799-811. A T-DNA-tagged population of Arabidopsis was screened fo...r mutations in AtOPT3, which encodes a member of the oligopeptide (OPT) family of peptide transporters, and a re...ed that most homozygous embryos were arrested at or before the octant stage of embryo development and that n...one showed the usual periclinal division leading to the formation of the protoderm. This defective phenotype could be re.... A beta-glucuronidase (GUS) fusion to DNA sequences upstream of the putative AtOPT3 ATG start codon was constructed, and the expre

  20. The Arabidopsis downy mildew resistance gene, RPP13-Nd, functions independently of NDR1 and EDS1 and does not require the accumulation of salicylic acid.

    Science.gov (United States)

    Bittner-Eddy, P D; Beynon, J L

    2001-03-01

    RPP13-Nd-mediated resistance prevents parasitism by five isolates of Peronospora parasitica (At) in a transgenic Arabidopsis. Columbia background. We tested the effect of a number of known disease resistance mutations on the RPP13-Nd function and found that resistance remained unaltered in plants carrying mutations in either EDS1 or NDR1 and in double ndr1-1/eds1-2 mutant lines. Furthermore, we found that pbs2, pad4-1, npr1-1, and rps5-1, which compromise resistance to a number of P. parasitica (At) isolates, had no affect on RPP13-Nd function. In addition, RPP13-Nd-mediated resistance remained unchanged in a background of salicylic acid depletion (nahG). We conclude that RPP13-Nd is the first Arabidopsis R gene product reported to act via a novel signaling pathway that is independent of salicylic acid-mediated responses and is completely independent of NDR1 and EDS1.

  1. NUCLEAR FUSION DEFECTIVE1 encodes the Arabidopsis RPL21M protein and is required for karyogamy during female gametophyte development and fertilization.

    Science.gov (United States)

    Portereiko, Michael F; Sandaklie-Nikolova, Linda; Lloyd, Alan; Dever, Chad A; Otsuga, Denichiro; Drews, Gary N

    2006-07-01

    Karyogamy, or nuclear fusion, is essential for sexual reproduction. In angiosperms, karyogamy occurs three times: twice during double fertilization of the egg cell and the central cell and once during female gametophyte development when the two polar nuclei fuse to form the diploid central cell nucleus. The molecular mechanisms controlling karyogamy are poorly understood. We have identified nine female gametophyte mutants in Arabidopsis (Arabidopsis thaliana), nuclear fusion defective1 (nfd1) to nfd9, that are defective in fusion of the polar nuclei. In the nfd1 to nfd6 mutants, failure of fusion of the polar nuclei is the only defect detected during megagametogenesis. nfd1 is also affected in karyogamy during double fertilization. Using transmission electron microscopy, we showed that nfd1 nuclei fail to undergo fusion of the outer nuclear membranes. nfd1 contains a T-DNA insertion in RPL21M that is predicted to encode the mitochondrial 50S ribosomal subunit L21, and a wild-type copy of this gene rescues the mutant phenotype. Consistent with the predicted function of this gene, an NFD1-green fluorescent protein fusion protein localizes to mitochondria and the NFD1/RPL21M gene is expressed throughout the plant. The nfd3, nfd4, nfd5, and nfd6 mutants also contain T-DNA insertions in genes predicted to encode proteins that localize to mitochondria, suggesting a role for this organelle in nuclear fusion.

  2. The UNUSUAL FLORAL ORGANS gene of Arabidopsis thaliana is an F-box protein required for normal patterning and growth in the floral meristem.

    Science.gov (United States)

    Samach, A; Klenz, J E; Kohalmi, S E; Risseeuw, E; Haughn, G W; Crosby, W L

    1999-11-01

    Genetic and molecular studies have suggested that the UNUSUAL FLORAL ORGANS (UFO) gene, from Arabidopsis thaliana, is expressed in all shoot apical meristems, and is involved in the regulation of a complex set of developmental events during floral development, including floral meristem and floral organ identity. Results from in situ hybridization using genes expressed early in floral development as probes indicate that UFO controls growth of young floral primordia. Transgenic constructs were used to provide evidence that UFO regulates floral organ identity by activating or maintaining transcription of the class B organ-identity gene APETALA 3, but not PISTILLATA. In an attempt to understand the biochemical mode of action of the UFO gene product, we show here that UFO is an F-box protein that interacts with Arabidopsis SKP1-like proteins, both in the yeast two-hybrid system and in vitro. In yeast and other organisms both F-box proteins and SKP1 homologues are subunits of specific ubiquitin E3 enzyme complexes that target specific proteins for degradation. The protein selected for degradation by the complex is specified by the F-box proteins. It is therefore possible that the role of UFO is to target for degradation specific proteins controlling normal growth patterns in the floral primordia, as well as proteins that negatively regulate APETALA 3 transcription.

  3. The Starch Granule-Associated Protein EARLY STARVATION1 Is Required for the Control of Starch Degradation in Arabidopsis thaliana Leaves.

    Science.gov (United States)

    Feike, Doreen; Seung, David; Graf, Alexander; Bischof, Sylvain; Ellick, Tamaryn; Coiro, Mario; Soyk, Sebastian; Eicke, Simona; Mettler-Altmann, Tabea; Lu, Kuan Jen; Trick, Martin; Zeeman, Samuel C; Smith, Alison M

    2016-06-01

    To uncover components of the mechanism that adjusts the rate of leaf starch degradation to the length of the night, we devised a screen for mutant Arabidopsis thaliana plants in which starch reserves are prematurely exhausted. The mutation in one such mutant, named early starvation1 (esv1), eliminates a previously uncharacterized protein. Starch in mutant leaves is degraded rapidly and in a nonlinear fashion, so that reserves are exhausted 2 h prior to dawn. The ESV1 protein and a similar uncharacterized Arabidopsis protein (named Like ESV1 [LESV]) are located in the chloroplast stroma and are also bound into starch granules. The region of highest similarity between the two proteins contains a series of near-repeated motifs rich in tryptophan. Both proteins are conserved throughout starch-synthesizing organisms, from angiosperms and monocots to green algae. Analysis of transgenic plants lacking or overexpressing ESV1 or LESV, and of double mutants lacking ESV1 and another protein necessary for starch degradation, leads us to propose that these proteins function in the organization of the starch granule matrix. We argue that their misexpression affects starch degradation indirectly, by altering matrix organization and, thus, accessibility of starch polymers to starch-degrading enzymes.

  4. A membrane microdomain-associated protein, Arabidopsis Flot1, is involved in a clathrin-independent endocytic pathway and is required for seedling development.

    Science.gov (United States)

    Li, Ruili; Liu, Peng; Wan, Yinglang; Chen, Tong; Wang, Qinli; Mettbach, Ursula; Baluska, Frantisek; Samaj, Jozef; Fang, Xiaohong; Lucas, William J; Lin, Jinxing

    2012-05-01

    Endocytosis is essential for the maintenance of protein and lipid compositions in the plasma membrane and for the acquisition of materials from the extracellular space. Clathrin-dependent and -independent endocytic processes are well established in yeast and animals; however, endocytic pathways involved in cargo internalization and intracellular trafficking remain to be fully elucidated for plants. Here, we used transgenic green fluorescent protein-flotillin1 (GFP-Flot1) Arabidopsis thaliana plants in combination with confocal microscopy analysis and transmission electron microscopy immunogold labeling to study the spatial and dynamic aspects of GFP-Flot1-positive vesicle formation. Vesicle size, as outlined by the gold particles, was ∼100 nm, which is larger than the 30-nm size of clathrin-coated vesicles. GFP-Flot1 also did not colocalize with clathrin light chain-mOrange. Variable-angle total internal reflection fluorescence microscopy also revealed that the dynamic behavior of GFP-Flot1-positive puncta was different from that of clathrin light chain-mOrange puncta. Furthermore, disruption of membrane microdomains caused a significant alteration in the dynamics of Flot1-positive puncta. Analysis of artificial microRNA Flot1 transgenic Arabidopsis lines established that a reduction in Flot1 transcript levels gave rise to a reduction in shoot and root meristem size plus retardation in seedling growth. Taken together, these findings support the hypothesis that, in plant cells, Flot1 is involved in a clathrin-independent endocytic pathway and functions in seedling development.

  5. 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.

  6. Regulation of ferulate-5-hydroxylase expression in Arabidopsis in the context of sinapate ester biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ruegger, M.; Meyer, K.; Cusumano, J.C.; Chapple, C. [Purdue Univ., West Lafayette, IN (United States). Dept. of Biochemistry

    1999-01-01

    Sinapic acid is an intermediate in syringyl lignin biosynthesis in angiosperms, and in some taxa serves as a precursor for soluble secondary metabolites. The biosynthesis and accumulation of the sinapate esters sinapoylglucose, sinapolymalate, and sinapolycholine are developmentally regulated in Arabidopsis and other members of the Brassicaceae. The FAH1 locus of Arabidopsis encodes the enzyme ferulate-5-hydroxylase (F5H), which catalyzes the rate-limiting step in syringyl lignin biosynthesis and is required for the production of sinapate esters. Here the authors show that F5H expression parallels sinapate ester accumulation in developing siliques and seedlings, but is not rate limiting for their biosynthesis. RNA gel-blot analysis indicated that the tissue-specific and developmentally regulated expression of F5H mRNA is distinct from that of other phenylpropanoid genes. Efforts to identify constructs capable of complementing the sinapate ester-deficient phenotype of fah1 mutants demonstrated that F5H expression in leaves is dependent on sequences 3{prime} of the F5H coding region. In contrast, the positive regulatory function of the downstream region is not required for F5H transcript or sinapolycholine accumulation in embryos.

  7. 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.

  8. Expression of chicken parvovirus VP2 in chicken embryo fibroblasts requires codon optimization for production of naked DNA and vectored meleagrid herpesvirus type 1 vaccines.

    Science.gov (United States)

    Spatz, Stephen J; Volkening, Jeremy D; Mullis, Robert; Li, Fenglan; Mercado, John; Zsak, Laszlo

    2013-10-01

    Meleagrid herpesvirus type 1 (MeHV-1) is an ideal vector for the expression of antigens from pathogenic avian organisms in order to generate vaccines. Chicken parvovirus (ChPV) is a widespread infectious virus that causes serious disease in chickens. It is one of the etiological agents largely suspected in causing Runting Stunting Syndrome (RSS) in chickens. Initial attempts to express the wild-type gene encoding the capsid protein VP2 of ChPV by insertion into the thymidine kinase gene of MeHV-1 were unsuccessful. However, transient expression of a codon-optimized synthetic VP2 gene cloned into the bicistronic vector pIRES2-Ds-Red2, could be demonstrated by immunocytochemical staining of transfected chicken embryo fibroblasts (CEFs). Red fluorescence could also be detected in these transfected cells since the red fluorescent protein gene is downstream from the internal ribosome entry site (IRES). Strikingly, fluorescence could not be demonstrated in cells transiently transfected with the bicistronic vector containing the wild-type or non-codon-optimized VP2 gene. Immunocytochemical staining of these cells also failed to demonstrate expression of wild-type VP2, indicating that the lack of expression was at the RNA level and the VP2 protein was not toxic to CEFs. Chickens vaccinated with a DNA vaccine consisting of the bicistronic vector containing the codon-optimized VP2 elicited a humoral immune response as measured by a VP2-specific ELISA. This VP2 codon-optimized bicistronic cassette was rescued into the MeHV-1 genome generating a vectored vaccine against ChPV disease.

  9. A simple and rapid flow cytometry-based assay to identify a competent embryo prior to embryo transfer

    Science.gov (United States)

    Pallinger, Eva; Bognar, Zoltan; Bodis, Jozsef; Csabai, Timea; Farkas, Nelli; Godony, Krisztina; Varnagy, Akos; Buzas, Edit; Szekeres-Bartho, Julia

    2017-01-01

    Multiple pregnancy is a risk for prematurity and preterm birth. The goal of assisted reproduction is to achieve a single pregnancy, by transferring a single embryo. This requires improved methods to identify the competent embryo. Here, we describe such a test, based on flow cytometric determination of the nucleic acid (PI+) containing extracellular vesicle (EV) count in day 5 embryo culture media. 88 women undergoing IVF were included in the study. More than 1 embryos were transferred to most patients. In 58 women, the transfer resulted in clinical pregnancy, whereas in 30 women in implantation failure. In 112 culture media of embryos from the “clinical pregnancy” group, the number of PI+ EVs was significantly lower than in those of 49 embryos, from the “implantation failure” group. In 14 women, transfer of a single embryo resulted in a singleton pregnancy, or, transfer of two embryos in twin pregnancy. The culture media of 19 out of the 20 “confirmed competent” embryos contained a lower level of PI+ EVs than the cut off level, suggesting that the competent embryo can indeed be identified by low PI+ EV counts. We developed a noninvasive, simple, inexpensive, quick test, which identifies the embryos that are most likely to implant. PMID:28057937

  10. The Arabidopsis aleurone layer responds to nitric oxide, gibberellin, and abscisic acid and is sufficient and necessary for seed dormancy.

    Science.gov (United States)

    Bethke, Paul C; Libourel, Igor G L; Aoyama, Natsuyo; Chung, Yong-Yoon; Still, David W; Jones, Russell L

    2007-03-01

    Seed dormancy is a common phase of the plant life cycle, and several parts of the seed can contribute to dormancy. Whole seeds, seeds lacking the testa, embryos, and isolated aleurone layers of Arabidopsis (Arabidopsis thaliana) were used in experiments designed to identify components of the Arabidopsis seed that contribute to seed dormancy and to learn more about how dormancy and germination are regulated in this species. The aleurone layer was found to be the primary determinant of seed dormancy. Embryos from dormant seeds, however, had a lesser growth potential than those from nondormant seeds. Arabidopsis aleurone cells were examined by light and electron microscopy, and cell ultrastructure was similar to that of cereal aleurone cells. Arabidopsis aleurone cells responded to nitric oxide (NO), gibberellin (GA), and abscisic acid, with NO being upstream of GA in a signaling pathway that leads to vacuolation of protein storage vacuoles and abscisic acid inhibiting vacuolation. Molecular changes that occurred in embryos and aleurone layers prior to germination were measured, and these data show that both the aleurone layer and the embryo expressed the NO-associated gene AtNOS1, but only the embryo expressed genes for the GA biosynthetic enzyme GA3 oxidase.

  11. Arabidopsis hybrid speciation processes.

    Science.gov (United States)

    Schmickl, Roswitha; Koch, Marcus A

    2011-08-23

    The genus Arabidopsis provides a unique opportunity to study fundamental biological questions in plant sciences using the diploid model species Arabidopsis thaliana and Arabidopsis lyrata. However, only a few studies have focused on introgression and hybrid speciation in Arabidopsis, although polyploidy is a common phenomenon within this genus. More recently, there is growing evidence of significant gene flow between the various Arabidopsis species. So far, we know Arabidopsis suecica and Arabidopsis kamchatica as fully stabilized allopolyploid species. Both species evolved during Pleistocene glaciation and deglaciation cycles in Fennoscandinavia and the amphi-Beringian region, respectively. These hybrid studies were conducted either on a phylogeographic scale or reconstructed experimentally in the laboratory. In our study we focus at a regional and population level. Our research area is located in the foothills of the eastern Austrian Alps, where two Arabidopsis species, Arabidopsis arenosa and A. lyrata ssp. petraea, are sympatrically distributed. Our hypothesis of genetic introgression, migration, and adaptation to the changing environment during the Pleistocene has been confirmed: We observed significant, mainly unidirectional gene flow between the two species, which has given rise to the tetraploid A. lyrata. This cytotype was able to escape from the narrow ecological niche occupied by diploid A. lyrata ssp. petraea on limestone outcrops by migrating northward into siliceous areas, leaving behind a trail of genetic differentiation.

  12. Reference: 428 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available on was delayed in the psb27 mutant, suggesting that Psb27 is required for efficient...icient repair of photodamaged photosystem II. 4-5 567-75...he involvement of this lumenal protein in the recovery process of PSII. A Psb27 homologue in Arabidopsis thaliana is required for eff

  13. 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....

  14. Contribution of gibberellins to the formation of Arabidopsis seed coat through starch degradation.

    Science.gov (United States)

    Kim, Young-Cheon; Nakajima, Masatoshi; Nakayama, Akira; Yamaguchi, Isomaro

    2005-08-01

    To clarify the role of gibberellins in the seed development of Arabidopsis, we investigated the sites where gibberellins are synthesized and induce alpha-amylase genes. The spatial and temporal expression of the genes encoding gibberellin biosynthetic enzymes and alpha-amylases was examined by reverse transcription-PCR (RT-PCR) and in situ hybridization. The mRNAs of AtGA20ox2, AtGA20ox3 and AtGA3ox4 began to be detectable 5-7 d after pollination. In situ hybridization showed that these genes were expressed almost simultaneously around starch granules in the outer integument, preceding the disappearance of those granules. AtGA20ox2 and AtGA3ox4 but not AtGA20ox3 also showed their signals at the rim of the developing embryo. The alpha-amylase gene, Amy3, which responded to gibberellin, was mainly expressed in the developing seed, spatially overlapping with the expression of AtGA20ox2 and AtGA3ox4. These results suggest that gibberellins function in at least two sites of the seed: the outer integument and part of the embryo. We examined the phenotypes of a T-DNA insertion line of AtGA3ox4 and observed the following: (i) a decrease of alpha-amylase gene transcripts in young siliques; (ii) delay of starch degradation in the outer integument; (iii) disarrangement of the seed surface structure; and (iv) abnormal swelling pattern of polysaccharides after imbibition by the mature seed. These characteristics are phenotypes of plants under gibberellin starvation, because the abnormalities could be almost overcome with applied gibberellin, and the gibberellin-treated mutant was indistinguishable from the wild type. These results strongly suggest that gibberellins in the outer integument would be required for the normal formation of the Arabidopsis seed coat.

  15. Flavonol-induced changes in PIN2 polarity and auxin transport in the Arabidopsis thaliana rol1-2 mutant require phosphatase activity

    Science.gov (United States)

    Kuhn, Benjamin M.; Nodzyński, Tomasz; Errafi, Sanae; Bucher, Rahel; Gupta, Shibu; Aryal, Bibek; Dobrev, Petre; Bigler, Laurent; Geisler, Markus; Zažímalová, Eva; Friml, Jiří; Ringli, Christoph

    2017-01-01

    The phytohormone auxin is a major determinant and regulatory component important for plant development. Auxin transport between cells is mediated by a complex system of transporters such as AUX1/LAX, PIN, and ABCB proteins, and their localization and activity is thought to be influenced by phosphatases and kinases. Flavonols have been shown to alter auxin transport activity and changes in flavonol accumulation in the Arabidopsis thaliana rol1-2 mutant cause defects in auxin transport and seedling development. A new mutation in ROOTS CURL IN NPA 1 (RCN1), encoding a regulatory subunit of the phosphatase PP2A, was found to suppress the growth defects of rol1-2 without changing the flavonol content. rol1-2 rcn1-3 double mutants show wild type-like auxin transport activity while levels of free auxin are not affected by rcn1-3. In the rol1-2 mutant, PIN2 shows a flavonol-induced basal-to-apical shift in polar localization which is reversed in the rol1-2 rcn1-3 to basal localization. In vivo analysis of PINOID action, a kinase known to influence PIN protein localization in a PP2A-antagonistic manner, revealed a negative impact of flavonols on PINOID activity. Together, these data suggest that flavonols affect auxin transport by modifying the antagonistic kinase/phosphatase equilibrium. PMID:28165500

  16. Induction of dormancy in Arabidopsis summer annuals requires parallel regulation of DOG1 and hormone metabolism by low temperature and CBF transcription factors.

    Science.gov (United States)

    Kendall, Sarah L; Hellwege, Anja; Marriot, Poppy; Whalley, Celina; Graham, Ian A; Penfield, Steven

    2011-07-01

    Summer annuals overwinter as seeds in the soil seed bank. This is facilitated by a cold-induced increase in dormancy during seed maturation followed by a switch to a state during seed imbibition in which cold instead promotes germination. Here, we show that the seed maturation transcriptome in Arabidopsis thaliana is highly temperature sensitive and reveal that low temperature during seed maturation induces several genes associated with dormancy, including DELAY OF GERMINATION1 (DOG1), and influences gibberellin and abscisic acid levels in mature seeds. Mutants lacking DOG1, or with altered gibberellin or abscisic acid synthesis or signaling, in turn show reduced ability to enter the deeply dormant states in response to low seed maturation temperatures. In addition, we find that DOG1 promotes gibberellin catabolism during maturation. We show that C-REPEAT BINDING FACTORS (CBFs) are necessary for regulation of dormancy and of GA2OX6 and DOG1 expression caused by low temperatures. However, the temperature sensitivity of CBF transcription is markedly reduced in seeds and is absent in imbibed seeds. Our data demonstrate that inhibition of CBF expression is likely a critical feature allowing cold to promote rather than inhibit germination and support a model in which CBFs act in parallel to a low-temperature signaling pathway in the regulation of dormancy.

  17. Induction of Dormancy in Arabidopsis Summer Annuals Requires Parallel Regulation of DOG1 and Hormone Metabolism by Low Temperature and CBF Transcription Factors[W][OA

    Science.gov (United States)

    Kendall, Sarah L.; Hellwege, Anja; Marriot, Poppy; Whalley, Celina; Graham, Ian A.; Penfield, Steven

    2011-01-01

    Summer annuals overwinter as seeds in the soil seed bank. This is facilitated by a cold-induced increase in dormancy during seed maturation followed by a switch to a state during seed imbibition in which cold instead promotes germination. Here, we show that the seed maturation transcriptome in Arabidopsis thaliana is highly temperature sensitive and reveal that low temperature during seed maturation induces several genes associated with dormancy, including DELAY OF GERMINATION1 (DOG1), and influences gibberellin and abscisic acid levels in mature seeds. Mutants lacking DOG1, or with altered gibberellin or abscisic acid synthesis or signaling, in turn show reduced ability to enter the deeply dormant states in response to low seed maturation temperatures. In addition, we find that DOG1 promotes gibberellin catabolism during maturation. We show that C-REPEAT BINDING FACTORS (CBFs) are necessary for regulation of dormancy and of GA2OX6 and DOG1 expression caused by low temperatures. However, the temperature sensitivity of CBF transcription is markedly reduced in seeds and is absent in imbibed seeds. Our data demonstrate that inhibition of CBF expression is likely a critical feature allowing cold to promote rather than inhibit germination and support a model in which CBFs act in parallel to a low-temperature signaling pathway in the regulation of dormancy. PMID:21803937

  18. Nuclear ribosome biogenesis mediated by the DIM1A rRNA dimethylase is required for organized root growth and epidermal patterning in Arabidopsis.

    Science.gov (United States)

    Wieckowski, Yana; Schiefelbein, John

    2012-07-01

    Position-dependent patterning of hair and non-hair cells in the Arabidopsis thaliana root epidermis is a powerful system to study the molecular basis of cell fate specification. Here, we report an epidermal patterning mutant affecting the ADENOSINE DIMETHYL TRANSFERASE 1A (DIM1A) rRNA dimethylase gene, predicted to participate in rRNA posttranscriptional processing and base modification. Consistent with a role in ribosome biogenesis, DIM1A is preferentially expressed in regions of rapid growth, and its product is nuclear localized with nucleolus enrichment. Furthermore, DIM1A preferentially accumulates in the developing hair cells, and the dim1A point mutant alters the cell-specific expression of the transcriptional regulators GLABRA2, CAPRICE, and WEREWOLF. Together, these findings suggest that establishment of cell-specific gene expression during root epidermis development is dependent upon proper ribosome biogenesis, possibly due to the sensitivity of the cell fate decision to relatively small differences in gene regulatory activities. Consistent with its effect on the predicted S-adenosyl-l-Met binding site, dim1A plants lack the two 18S rRNA base modifications but exhibit normal pre-rRNA processing. In addition to root epidermal defects, the dim1A mutant exhibits abnormal root meristem division, leaf development, and trichome branching. Together, these findings provide new insights into the importance of rRNA base modifications and translation regulation for plant growth and development.

  19. The small subunit 1 of the Arabidopsis isopropylmalate isomerase is required for normal growth and development and the early stages of glucosinolate formation.

    Science.gov (United States)

    Imhof, Janet; Huber, Florian; Reichelt, Michael; Gershenzon, Jonathan; Wiegreffe, Christoph; Lächler, Kurt; Binder, Stefan

    2014-01-01

    In Arabidopsis thaliana the evolutionary and functional relationship between Leu biosynthesis and the Met chain elongation pathway, the first part of glucosinolate formation, is well documented. Nevertheless the exact functions of some pathway components are still unclear. Isopropylmalate isomerase (IPMI), an enzyme usually involved in Leu biosynthesis, is a heterodimer consisting of a large and a small subunit. While the large protein is encoded by a single gene (isopropylmalate isomerase large subunit1), three genes encode small subunits (isopropylmalate isomerase small subunit1 to 3). We have now analyzed small subunit 1 (isopropylmalate isomerase small subunit1) employing artificial microRNA for a targeted knockdown of the encoding gene. Strong reduction of corresponding mRNA levels to less than 5% of wild-type levels resulted in a severe phenotype with stunted growth, narrow pale leaf blades with green vasculature and abnormal adaxial-abaxial patterning as well as anomalous flower morphology. Supplementation of the knockdown plants with leucine could only partially compensate for the morphological and developmental abnormalities. Detailed metabolite profiling of the knockdown plants revealed changes in the steady state levels of isopropylmalate and glucosinolates as well as their intermediates demonstrating a function of IPMI SSU1 in both leucine biosynthesis and the first cycle of Met chain elongation. Surprisingly the levels of free leucine slightly increased suggesting an imbalanced distribution of leucine within cells and/or within plant tissues.

  20. The small subunit 1 of the Arabidopsis isopropylmalate isomerase is required for normal growth and development and the early stages of glucosinolate formation.

    Directory of Open Access Journals (Sweden)

    Janet Imhof

    Full Text Available In Arabidopsis thaliana the evolutionary and functional relationship between Leu biosynthesis and the Met chain elongation pathway, the first part of glucosinolate formation, is well documented. Nevertheless the exact functions of some pathway components are still unclear. Isopropylmalate isomerase (IPMI, an enzyme usually involved in Leu biosynthesis, is a heterodimer consisting of a large and a small subunit. While the large protein is encoded by a single gene (isopropylmalate isomerase large subunit1, three genes encode small subunits (isopropylmalate isomerase small subunit1 to 3. We have now analyzed small subunit 1 (isopropylmalate isomerase small subunit1 employing artificial microRNA for a targeted knockdown of the encoding gene. Strong reduction of corresponding mRNA levels to less than 5% of wild-type levels resulted in a severe phenotype with stunted growth, narrow pale leaf blades with green vasculature and abnormal adaxial-abaxial patterning as well as anomalous flower morphology. Supplementation of the knockdown plants with leucine could only partially compensate for the morphological and developmental abnormalities. Detailed metabolite profiling of the knockdown plants revealed changes in the steady state levels of isopropylmalate and glucosinolates as well as their intermediates demonstrating a function of IPMI SSU1 in both leucine biosynthesis and the first cycle of Met chain elongation. Surprisingly the levels of free leucine slightly increased suggesting an imbalanced distribution of leucine within cells and/or within plant tissues.

  1. Accurate Chromosome Segregation at First Meiotic Division Requires AGO4, a Protein Involved in RNA-Dependent DNA Methylation in Arabidopsis thaliana.

    Science.gov (United States)

    Oliver, Cecilia; Santos, Juan Luis; Pradillo, Mónica

    2016-10-01

    The RNA-directed DNA methylation (RdDM) pathway is important for the transcriptional repression of transposable elements and for heterochromatin formation. Small RNAs are key players in this process by regulating both DNA and histone methylation. Taking into account that methylation underlies gene silencing and that there are genes with meiosis-specific expression profiles, we have wondered whether genes involved in RdDM could play a role during this specialized cell division. To address this issue, we have characterized meiosis progression in pollen mother cells from Arabidopsis thaliana mutant plants defective for several proteins related to RdDM. The most relevant results were obtained for ago4-1 In this mutant, meiocytes display a slight reduction in chiasma frequency, alterations in chromatin conformation around centromeric regions, lagging chromosomes at anaphase I, and defects in spindle organization. These abnormalities lead to the formation of polyads instead of tetrads at the end of meiosis, and might be responsible for the fertility defects observed in this mutant. Findings reported here highlight an involvement of AGO4 during meiosis by ensuring accurate chromosome segregation at anaphase I.

  2. The Maize Viviparous8 locus, encoding a putative ALTERED MERISTEM PROGRAM1-like peptidase, regulates abscisic acid accumulation and coordinates embryo and endosperm development.

    Science.gov (United States)

    Suzuki, Masaharu; Latshaw, Susan; Sato, Yutaka; Settles, A Mark; Koch, Karen E; Hannah, L Curtis; Kojima, Mikiko; Sakakibara, Hitoshi; McCarty, Donald R

    2008-03-01

    We describe a mutant of Zea mays isolated from a W22 inbred transposon population, widow's peak mutant1 (wpk1), with an altered pattern of anthocyanin synthesis and aleurone cell differentiation in endosperm. In addition, a failure of the developing mutant embryo to form leaf initials is associated with decreased expression of a subset of meristem regulatory genes that includes Abphyl1 and Td1. We show that the viviparous8 (vp8) mutant has a similar pleiotropic phenotype in the W22 inbred background in contrast to the viviparous embryo phenotype exhibited in the standard genetic background, and we confirmed that wpk1 is allelic to vp8. Further genetic analysis revealed that the standard vp8 stock contains an unlinked, partially dominant suppressor of the vp8 mutation that is not present in W22. Consistent with the early-onset viviparous phenotype of vp8, expression of several embryonic regulators, including LEC1/B3 domain transcription factors, was reduced in the mutant embryo. Moreover, reduced abscisic acid (ABA) content of vp8/wpk1 embryos was correlated with altered regulation of ABA biosynthesis, as well as ABA catabolic pathways. The ABA biosynthetic gene Vp14 was down-regulated in the nonsuppressed background, whereas the ZmABA8'oxA1a ABA 8'-hydroxylase gene was strongly up-regulated in both genetic backgrounds. Molecular analysis revealed that Vp8 encodes a putative peptidase closely related to Arabidopsis thaliana ALTERED MERISTEM PROGRAM1. Because the Vp8 regulates meristem development as well as seed maturation processes, including ABA accumulation, we propose that VP8 is required for synthesis of an unidentified signal that integrates meristem and embryo formation in seeds.

  3. The Maize Viviparous8 Locus, Encoding a Putative ALTERED MERISTEM PROGRAM1-Like Peptidase, Regulates Abscisic Acid Accumulation and Coordinates Embryo and Endosperm Development1[W

    Science.gov (United States)

    Suzuki, Masaharu; Latshaw, Susan; Sato, Yutaka; Settles, A. Mark; Koch, Karen E.; Hannah, L. Curtis; Kojima, Mikiko; Sakakibara, Hitoshi; McCarty, Donald R.

    2008-01-01

    We describe a mutant of Zea mays isolated from a W22 inbred transposon population, widow's peak mutant1 (wpk1), with an altered pattern of anthocyanin synthesis and aleurone cell differentiation in endosperm. In addition, a failure of the developing mutant embryo to form leaf initials is associated with decreased expression of a subset of meristem regulatory genes that includes Abphyl1 and Td1. We show that the viviparous8 (vp8) mutant has a similar pleiotropic phenotype in the W22 inbred background in contrast to the viviparous embryo phenotype exhibited in the standard genetic background, and we confirmed that wpk1 is allelic to vp8. Further genetic analysis revealed that the standard vp8 stock contains an unlinked, partially dominant suppressor of the vp8 mutation that is not present in W22. Consistent with the early-onset viviparous phenotype of vp8, expression of several embryonic regulators, including LEC1/B3 domain transcription factors, was reduced in the mutant embryo. Moreover, reduced abscisic acid (ABA) content of vp8/wpk1 embryos was correlated with altered regulation of ABA biosynthesis, as well as ABA catabolic pathways. The ABA biosynthetic gene Vp14 was down-regulated in the nonsuppressed background, whereas the ZmABA8′oxA1a ABA 8′-hydroxylase gene was strongly up-regulated in both genetic backgrounds. Molecular analysis revealed that Vp8 encodes a putative peptidase closely related to Arabidopsis thaliana ALTERED MERISTEM PROGRAM1. Because the Vp8 regulates meristem development as well as seed maturation processes, including ABA accumulation, we propose that VP8 is required for synthesis of an unidentified signal that integrates meristem and embryo formation in seeds. PMID:18203869

  4. Constitutive disease resistance requires EDS1 in the Arabidopsis mutants cpr1 and cpr6 and is partially EDS1-dependent in cpr5.

    Science.gov (United States)

    Clarke, J D; Aarts, N; Feys, B J; Dong, X; Parker, J E

    2001-05-01

    The systemic acquired resistance (SAR) response in Arabidopsis is characterized by the accumulation of salicylic acid (SA), expression of the pathogenesis-related (PR) genes, and enhanced resistance to virulent bacterial and oomycete pathogens. The cpr (constitutive expressor of PR genes) mutants express all three SAR phenotypes. In addition, cpr5 and cpr6 induce expression of PDF1.2, a defense-related gene associated with activation of the jasmonate/ethylene-mediated resistance pathways. cpr5 also forms spontaneous lesions. In contrast, the eds1 (enhanced disease susceptibility) mutation abolishes race-specific resistance conferred by a major subclass of resistance (R) gene products in response to avirulent pathogens. eds1 plants also exhibit increased susceptibility to virulent pathogens. Epistasis experiments were designed to explore the relationship between the cpr- and EDS1-mediated resistance pathways. We found that a null eds1 mutation suppresses the disease resistance phenotypes of both cpr1 and cpr6. In contrast, eds1 only partially suppresses resistance in cpr5, leading us to conclude that cpr5 expresses both EDS1-dependent and EDS1-independent components of plant disease resistance. Although eds1 does not prevent lesion formation on cpr5 leaves, it alters their appearance and reduces their spread. This phenotypic difference is associated with increased pathogen colonization of cpr5 eds1 plants compared to cpr5. The data allow us to place EDS1 as a necessary downstream component of cpr1- and cpr6-mediated responses, but suggest a more complex relationship between EDS1 and cpr5 in plant defense.

  5. Beta-AMYLASE4, a noncatalytic protein required for starch breakdown, acts upstream of three active beta-amylases in Arabidopsis chloroplasts.

    Science.gov (United States)

    Fulton, Daniel C; Stettler, Michaela; Mettler, Tabea; Vaughan, Cara K; Li, Jing; Francisco, Perigio; Gil, Manuel; Reinhold, Heike; Eicke, Simona; Messerli, Gaëlle; Dorken, Gary; Halliday, Karen; Smith, Alison M; Smith, Steven M; Zeeman, Samuel C

    2008-04-01

    This work investigated the roles of beta-amylases in the breakdown of leaf starch. Of the nine beta-amylase (BAM)-like proteins encoded in the Arabidopsis thaliana genome, at least four (BAM1, -2, -3, and -4) are chloroplastic. When expressed as recombinant proteins in Escherichia coli, BAM1, BAM2, and BAM3 had measurable beta-amylase activity but BAM4 did not. BAM4 has multiple amino acid substitutions relative to characterized beta-amylases, including one of the two catalytic residues. Modeling predicts major differences between the glucan binding site of BAM4 and those of active beta-amylases. Thus, BAM4 probably lost its catalytic capacity during evolution. Total beta-amylase activity was reduced in leaves of bam1 and bam3 mutants but not in bam2 and bam4 mutants. The bam3 mutant had elevated starch levels and lower nighttime maltose levels than the wild type, whereas bam1 did not. However, the bam1 bam3 double mutant had a more severe phenotype than bam3, suggesting functional overlap between the two proteins. Surprisingly, bam4 mutants had elevated starch levels. Introduction of the bam4 mutation into the bam3 and bam1 bam3 backgrounds further elevated the starch levels in both cases. These data suggest that BAM4 facilitates or regulates starch breakdown and operates independently of BAM1 and BAM3. Together, our findings are consistent with the proposal that beta-amylase is a major enzyme of starch breakdown in leaves, but they reveal unexpected complexity in terms of the specialization of protein function.

  6. The Arabidopsis thaliana lectin receptor kinase LecRK-I.9 is required for full resistance to Pseudomonas syringae and affects jasmonate signalling.

    Science.gov (United States)

    Balagué, Claudine; Gouget, Anne; Bouchez, Olivier; Souriac, Camille; Haget, Nathalie; Boutet-Mercey, Stéphanie; Govers, Francine; Roby, Dominique; Canut, Hervé

    2016-07-11

    On microbial attack, plants can detect invaders and activate plant innate immunity. For the detection of pathogen molecules or cell wall damage, plants employ receptors that trigger the activation of defence responses. Cell surface proteins that belong to large families of lectin receptor kinases are candidates to function as immune receptors. Here, the function of LecRK-I.9 (At5g60300), a legume-type lectin receptor kinase involved in cell wall-plasma membrane contacts and in extracellular ATP (eATP) perception, was studied through biochemical, gene expression and reverse genetics approaches. In Arabidopsis thaliana, LecRK-I.9 expression is rapidly, highly and locally induced on inoculation with avirulent strains of Pseudomonas syringae pv. tomato (Pst). Two allelic lecrk-I.9 knock-out mutants showed decreased resistance to Pst. Conversely, over-expression of LecRK-I.9 led to increased resistance to Pst. The analysis of defence gene expression suggests an alteration of both the salicylic acid (SA) and jasmonic acid (JA) signalling pathways. In particular, LecRK-I.9 expression during plant-pathogen interaction was dependent on COI1 (CORONATINE INSENSITIVE 1) and JAR1 (JASMONATE RESISTANT 1) components, and JA-responsive transcription factors (TFs) showed altered levels of expression in plants over-expressing LecRK-I.9. A similar misregulation of these TFs was obtained by JA treatment. This study identified LecRK-I.9 as necessary for full resistance to Pst and demonstrated its involvement in the control of defence against pathogens through a regulation of JA signalling components. The role of LecRK-I.9 is discussed with regard to the potential molecular mechanisms linking JA signalling to cell wall damage and/or eATP perception.

  7. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Science.gov (United States)

    2010-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... 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)...

  8. [Medical, ethical and legal issues in cryopreservation of human embryos].

    Science.gov (United States)

    Beca, Juan Pablo; Lecaros, Alberto; González, Patricio; Sanhueza, Pablo; Mandakovic, Borislava

    2014-07-01

    Embryo cryopreservation improves efficiency and security of assisted reproduction techniques. Nonetheless, it can be questionable, so it must be justified from technical, legal and ethical points of view. This article analyses these perspectives. Embryo cryopreservation maximizes the probability of pregnancy, avoids new ovary stimulations and reduces the occurrence of multiple gestations. There is consensus that the in vitro embryo deserves legal protection by its own, although not as a newborn. Very few countries prohibit embryo cryopreservation based on the legal duty to protect human life since fecundation. Those countries that allow it, privilege women's reproductive rights. In Chile and in Latin America, no laws have been promulgated to regulate human assisted reproduction. The moral status of the embryo depends on how it is considered. Some believe it is a potential person while others think it is just a group of cells, but all recognize that it requires some kind of respect and protection. There is lack of information about the number of frozen embryos and their final destination. As a conclusion the authors propose that women or couples should have the right to decide autonomously, while institutions ought to be clear in their regulations. And the legislation must establish the legal status of the embryo before its implantation, the couples' rights and the regulation of the embryo cryopreservation. Personal, institutional or legal decisions must assume a concept about the moral status of the human embryo and try to avoid their destruction or indefinite storage.

  9. Cappuccino, a Drosophila maternal effect gene required for polarity of the egg and embryo, is related to the vertebrate limb deformity locus.

    Science.gov (United States)

    Emmons, S; Phan, H; Calley, J; Chen, W; James, B; Manseau, L

    1995-10-15

    We report the molecular isolation of cappuccino (capu), a gene required for localization of molecular determinants within the developing Drosophila oocyte. The carboxy-terminal half of the capu protein is closely related to that of the vertebrate limb deformity locus, which is known to function in polarity determination in the developing vertebrate limb. In addition, capu shares both a proline-rich region and a 70-amino-acid domain with a number of other genes, two of which also function in pattern formation, the Saccharomyes cerevisiae BNI1 gene and the Aspergillus FigA gene. We also show that capu mutant oocytes have abnormal microtubule distributions and premature microtubule-based cytoplasmic streaming within the oocyte, but that neither the speed nor the timing of the cytoplasmic streaming correlates with the strength of the mutant allele. This suggests that the premature cytoplasmic streaming in capu mutant oocytes does not suffice to explain the patterning defects. By inducing cytoplasmic streaming in wild-type oocytes during mid-oogenesis, we show that premature cytoplasmic streaming can displace staufen protein from the posterior pole, but not gurken mRNA from around the oocyte nucleus.

  10. 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.

  11. Reference: 392 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available pment. The Arabidopsis SUPPRESSOR OF AUXIN RESISTANCE proteins are nucleoporins with an important role in ho...olyadenylated RNA within the nucleus, indicating that SAR1 and SAR3 are required for mRNA export. Our results demonstrate the importa...nt role of the plant NPC in hormone signaling and develo

  12. Reference: 713 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available between the galactosyl side-chain structure of pectin and its physical properties...with correct hydration properties. 12 4007-21 18165329 2007 Dec The Plant cell Carpita Nicholas C|Dean Gilli.... The Arabidopsis MUM2 gene encodes a beta-galactosidase required for the production of seed coat mucilage

  13. Reference: 620 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available 620 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u17543866i Nodine Michael...or-like kinases redundantly required for arabidopsis embryonic pattern formation. 6 943-56 17543866 2007 Jun Developmental cell Nodine Michael D|Tax Frans E|Yadegari Ramin

  14. 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)

  15. 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

  16. 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.

  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. Sex determination of duck embryos: observations on syrinx development

    Science.gov (United States)

    Wilson, Robert E.; Sonsthagen, Sarah A.; Franson, J. Christian

    2013-01-01

    Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

  19. 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.

  20. Genetic analysis of two OsLpa1-like genes in Arabidopsis reveals that only one is required for wild-type seed phytic acid levels

    Science.gov (United States)

    Phytic acid (inositol-1,2,3,4,5,6-hexakisphosphate or InsP6) is the primary storage form of phosphorus in plant seeds. The rice OsLpa1 encodes a novel protein required for wild-type levels of seed InsP6 and was identified from a low phytic acid (lpa) mutant exhibiting a 45-50% reduction in seed InsP...

  1. 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

  2. Optimizing the culture environment and embryo manipulation to help maintain embryo developmental potential.

    Science.gov (United States)

    Swain, Jason E; Carrell, Doug; Cobo, Ana; Meseguer, Marcos; Rubio, Carmen; Smith, Gary D

    2016-03-01

    With increased use of comprehensive chromosome screening (CCS), the question remains as to why some practices do not experience the same high levels of clinical success after implementation of the approach. Indeed, the debate surrounding the efficacy and usefulness of blastocyst biopsy and CCS continues. Importantly, several variables impact the success of an assisted reproductive technology cycle. Transfer of a euploid embryo is but one factor in an intricate system that requires numerous steps to occur successfully. Certainly, the culture environment and the manipulations of the embryo during its time in the laboratory can impact its reproductive potential. Environmental stressors ranging from culture media to culture conditions and even culture platform can impact biochemical, metabolic, and epigenetic patterns that can affect the developing cell independent of chromosome number. Furthermore, accompanying procedures, such as biopsy and vitrification, are complex and, when performed improperly, can negatively impact embryo quality. These are areas that likely still carry room for improvement within the IVF laboratory.

  3. Utero-tubal embryo transfer and vasectomy in the mouse model.

    Science.gov (United States)

    Bermejo-Alvarez, Pablo; Park, Ki-Eun; Telugu, Bhanu P

    2014-02-28

    The transfer of preimplantation embryos to a surrogate female is a required step for the production of genetically modified mice or to study the effects of epigenetic alterations originated during preimplantation development on subsequent fetal development and adult health. The use of an effective and consistent embryo transfer technique is crucial to enhance the generation of genetically modified animals and to determine the effect of different treatments on implantation rates and survival to term. Embryos at the blastocyst stage are usually transferred by uterine transfer, performing a puncture in the uterine wall to introduce the embryo manipulation pipette. The orifice performed in the uterus does not close after the pipette has been withdrawn, and the embryos can outflow to the abdominal cavity due to the positive pressure of the uterus. The puncture can also produce a hemorrhage that impairs implantation, blocks the transfer pipette and may affect embryo development, especially when embryos without zona are transferred. Consequently, this technique often results in very variable and overall low embryo survival rates. Avoiding these negative effects, utero-tubal embryo transfer take advantage of the utero-tubal junction as a natural barrier that impedes embryo outflow and avoid the puncture of the uterine wall. Vasectomized males are required for obtaining pseudopregnant recipients. A technique to perform vasectomy is described as a complement to the utero-tubal embryo transfer.

  4. The plastid-localized NAD-dependent malate dehydrogenase is crucial for energy homeostasis in developing Arabidopsis thaliana seeds.

    Science.gov (United States)

    Selinski, Jennifer; König, Nicolas; Wellmeyer, Benedikt; Hanke, Guy T; Linke, Vera; Neuhaus, H Ekkehard; Scheibe, Renate

    2014-01-01

    In the absence of photosynthesis, ATP is imported into chloroplasts and non-green plastids by ATP/ADP transporters or formed during glycolysis, the latter requiring continuous regeneration of NAD(+), supplied by the plastidial isoform of NAD-MDH. During screening for T-DNA insertion mutants in the plNAD-MDH gene of Arabidopsis, only heterozygous plants could be isolated and homozygous knockout mutants grew only after complementation. These heterozygous plants show higher transcript levels of an alternative NAD(+)-regenerating enzyme, NADH-GOGAT, and, remarkably, improved growth when ammonium is the sole N-source. In situ hybridization and GUS-histochemical staining revealed that plNAD-MDH was particularly abundant in male and female gametophytes. Knockout plNAD-MDH pollen exhibit impaired tube growth in vitro, which can be overcome by adding the substrates of NADH-GOGAT. In vivo, knockout pollen is able to fertilize the egg cell. Young siliques of selfed heterozygous plants contain both green and white seeds corresponding to wild-type/heterozygous (green) and homozygous knockout mutants (white) in a (1:2):1 ratio. Embryos of the homozygous knockout seeds only reached the globular stage, did not green, and developed to tiny wrinkled seeds. Complementation with the gene under the native promoter rescued this defect, and all seeds developed as wild-type. This suggests that a blocked major physiological process in plNAD-MDH mutants stops both embryo and endosperm development, thus avoiding assimilate investment in compromised offspring.

  5. Gender determination of avian embryo

    Science.gov (United States)

    Daum, Keith A.; Atkinson, David A.

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  6. Reference: 517 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available d isolated aleurone layers of Arabidopsis (Arabidopsis thaliana) were used in experiments designed to iden...tify components of the Arabidopsis seed that contribute to seed dormancy and to lea

  7. Reference: 34 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available al gene in different tissues, under normal growth conditions, and when the plants were subjected to anoxia or other environmental...e1 gene of Arabidopsis is required during anoxia but not other environmental stre...ronmental stresses. We also characterize the expression of the aldehyde dehydrogena...ed under oxygen limitation among the PDC1 gene family and that a pdc1 null mutant is comprised in anoxia tolerance but not other envi

  8. TAF13 interacts with PRC2 members and is essential for Arabidopsis seed development.

    Science.gov (United States)

    Lindner, Matias; Simonini, Sara; Kooiker, Maarten; Gagliardini, Valeria; Somssich, Marc; Hohenstatt, Mareike; Simon, Rüdiger; Grossniklaus, Ueli; Kater, Martin M

    2013-07-01

    TBP-Associated Factors (TAFs) are components of complexes like TFIID, TFTC, SAGA/STAGA and SMAT that are important for the activation of transcription, either by establishing the basic transcription machinery or by facilitating histone acetylation. However, in Drosophila embryos several TAFs were shown to be associated with the Polycomb Repressive Complex 1 (PRC1), even though the role of this interaction remains unclear. Here we show that in Arabidopsis TAF13 interacts with MEDEA and SWINGER, both members of a plant variant of Polycomb Repressive Complex 2 (PRC2). PRC2 variants play important roles during the plant life cycle, including seed development. The taf13 mutation causes seed defects, showing embryo arrest at the 8-16 cell stage and over-proliferation of the endosperm in the chalazal region, which is typical for Arabidopsis PRC2 mutants. Our data suggest that TAF13 functions together with PRC2 in transcriptional regulation during seed development.

  9. Developmental toxicity assay using high content screening of zebrafish embryos.

    Science.gov (United States)

    Lantz-McPeak, Susan; Guo, Xiaoqing; Cuevas, Elvis; Dumas, Melanie; Newport, Glenn D; Ali, Syed F; Paule, Merle G; Kanungo, Jyotshna

    2015-03-01

    Typically, time-consuming standard toxicological assays using the zebrafish (Danio rerio) embryo model evaluate mortality and teratogenicity after exposure during the first 2 days post-fertilization. Here we describe an automated image-based high content screening (HCS) assay to identify the teratogenic/embryotoxic potential of compounds in zebrafish embryos in vivo. Automated image acquisition was performed using a high content microscope system. Further automated analysis of embryo length, as a statistically quantifiable endpoint of toxicity, was performed on images post-acquisition. The biological effects of ethanol, nicotine, ketamine, caffeine, dimethyl sulfoxide and temperature on zebrafish embryos were assessed. This automated developmental toxicity assay, based on a growth-retardation endpoint should be suitable for evaluating the effects of potential teratogens and developmental toxicants in a high throughput manner. This approach can significantly expedite the screening of potential teratogens and developmental toxicants, thereby improving the current risk assessment process by decreasing analysis time and required resources.

  10. The moral status of the embryo post-Dolly.

    Science.gov (United States)

    Stanton, Catherine; Harris, John

    2005-04-01

    Cameron and Williamson have provided a provocative and timely review of the ethical questions prompted by the birth of Dolly. The question Cameron and Williamson seek to address is "In the world of Dolly, when does a human embryo acquire respect?". Their initial discussion sets the scene by providing a valuable overview of attitudes towards the embryo, summarising various religious, scientific, and philosophical viewpoints. They then ask, "What has Dolly changed?" and identify five changes, the first being that fertilisation is no longer required to create an embryo. Following this analysis they then ask when an embryo created other than by fertilisation begins to acquire respect. This paper explores the ethical and legal issues highlighted by Cameron and Williamson's paper.

  11. Viability of bovine demi embryo after splitting of fresh and frozen thawed embryo derived from in vitro embryo production

    Directory of Open Access Journals (Sweden)

    M Imron

    2007-06-01

    Full Text Available In vivo embryo production was limited by number of donor, wide variability respond due to superovulation program and also immunoactifity of superovulation hormone (FSH. Splitting technology could be an alternative to increase the number of transferrable embryos into recipien cows. Splitting is done with cutting embryo becoming two equal pieces (called demi embrio base on ICM orientation. The objective of this research was to determine the viability of demi embryo obtained from embryo splitting of fresh and frozen thawed embryo. The results showed that demi embryos which performed blastocoel reexpansion 3 hours after embryo splitting using fresh and frozen thawed embryos were 76.9 and 76.2% respectively. Base on existention of inner cell mass (ICM, the number of demi embryos developed with ICM from fresh and frozen thawed embryos were not significantly different (90.6 and 85.7% respectively. The cell number of demi embryo from fresh embryos splitting was not different compared with those from frozen thawed embryos (36.1 and 35.9 respectively. These finding indicated that embryo splitting can be applied to frozen thawed embryos with certain condition as well as fresh embryos.

  12. Embryo mechanics: balancing force production with elastic resistance during morphogenesis.

    Science.gov (United States)

    Davidson, Lance A

    2011-01-01

    Morphogenesis requires the spatial and temporal control of embryo mechanics, including force production and mechanical resistance to those forces, to coordinate tissue deformation and large-scale movements. Thus, biomechanical processes play a key role in directly shaping the embryo. Additional roles for embryo mechanics during development may include the patterning of positional information and to provide feedback to ensure the success of morphogenetic movements in shaping the larval body and organs. To understand the multiple roles of mechanics during development requires familiarity with engineering principles of the mechanics of structures, the viscoelastic properties of biomaterials, and the integration of force and stress within embryonic structures as morphogenesis progresses. In this chapter, we review the basic engineering principles of biomechanics as they relate to morphogenesis, introduce methods for quantifying embryo mechanics and the limitations of these methods, and outline a formalism for investigating the role of embryo mechanics in birth defects. We encourage the nascent field of embryo mechanics to adopt standard engineering terms and test methods so that studies of diverse organisms can be compared and universal biomechanical principles can be revealed.

  13. Physical influences on embryo development.

    Science.gov (United States)

    Deeming, D C; Rowlett, K; Simkiss, K

    1987-01-01

    There is a critical period between 3 and 7 days of incubation when the absence of turning in eggs of the domestic fowl leads to increased mortality and decreased embryo growth. This critical period coincides with the time of subembryonic fluid formation, and it is suggested that the absence of turning leads to the presence of unstirred layer effects in fluid secretion. This fluid deficiency persists throughout the subsequent development of the embryo. Experiments on shell-less culture systems support this interpretation in preference to other explanations of embryo death in unturned eggs, which usually refer to chorion adhesion to shell membranes.

  14. New techniques on embryo manipulation.

    Science.gov (United States)

    Escribá, M J; Valbuena, D; Remohí, J; Pellicer, A; Simón, C

    2002-01-01

    For many years, experience has been accumulated on embryo and gamete manipulation in livestock animals. The present work is a review of these techniques and their possible application in human embryology in specific cases. It is possible to manipulate gametes at different levels, producing paternal or maternal haploid embryos (hemicloning), using different techniques including nuclear transfer. At the embryonic stage, considering practical, ethical and legal issues, techniques will be reviewed that include cloning and embryo splitting at the cleavage stage, morula, or blastocyst stage.

  15. How frog embryos replicate their DNA reliably

    Science.gov (United States)

    Bechhoefer, John; Marshall, Brandon

    2007-03-01

    Frog embryos contain three billion base pairs of DNA. In early embryos (cycles 2-12), DNA replication is extremely rapid, about 20 min., and the entire cell cycle lasts only 25 min., meaning that mitosis (cell division) takes place in about 5 min. In this stripped-down cell cycle, there are no efficient checkpoints to prevent the cell from dividing before its DNA has finished replication - a disastrous scenario. Even worse, the many origins of replication are laid down stochastically and are also initiated stochastically throughout the replication process. Despite the very tight time constraints and despite the randomness introduced by origin stochasticity, replication is extremely reliable, with cell division failing no more than once in 10,000 tries. We discuss a recent model of DNA replication that is drawn from condensed-matter theories of 1d nucleation and growth. Using our model, we discuss different strategies of replication: should one initiate all origins as early as possible, or is it better to hold back and initiate some later on? Using concepts from extreme-value statistics, we derive the distribution of replication times given a particular scenario for the initiation of origins. We show that the experimentally observed initiation strategy for frog embryos meets the reliability constraint and is close to the one that requires the fewest resources of a cell.

  16. mCSF1, a nucleus-encoded CRM protein required for the processing of many mitochondrial introns, is involved in the biogenesis of respiratory complexes I and IV in Arabidopsis.

    Science.gov (United States)

    Zmudjak, Michal; Colas des Francs-Small, Catherine; Keren, Ido; Shaya, Felix; Belausov, Eduard; Small, Ian; Ostersetzer-Biran, Oren

    2013-07-01

    The coding regions of many mitochondrial genes in plants are interrupted by intervening sequences that are classified as group II introns. Their splicing is essential for the expression of the genes they interrupt and hence for respiratory function, and is facilitated by various protein cofactors. Despite the importance of these cofactors, only a few of them have been characterized. CRS1-YhbY domain (CRM) is a recently recognized RNA-binding domain that is present in several characterized splicing factors in plant chloroplasts. The Arabidopsis genome encodes 16 CRM proteins, but these are largely uncharacterized. Here, we analyzed the intracellular location of one of these hypothetical proteins in Arabidopsis, mitochondrial CAF-like splicing factor 1 (mCSF1; At4 g31010), and analyzed the growth phenotypes and organellar activities associated with mcsf1 mutants in plants. Our data indicated that mCSF1 resides within mitochondria and its functions are essential during embryogenesis. Mutant plants with reduced mCSF1 displayed inhibited germination and retarded growth phenotypes that were tightly associated with reduced complex I and IV activities. Analogously to the functions of plastid-localized CRM proteins, analysis of the RNA profiles in wildtype and mcsf1 plants showed that mCSF1 acts in the splicing of many of the group II intron RNAs in Arabidopsis mitochondria.

  17. Phaseolus immature embryo rescue technology.

    Science.gov (United States)

    Geerts, Pascal; Toussaint, André; Mergeai, Guy; Baudoin, Jean-Pierre

    2011-01-01

    Predominant among the production constraints of the common bean Phaseolus vulgaris are infestation of Ascochyta blight, Bean Golden Mosaic virus (BGMV), and Bean Fly. Interbreeding with Phaseolus -coccineus L. and/or Phaseolus polyanthus Greenm has been shown to provide P. vulgaris with greater resistance to these diseases. For interspecific crosses to be successful, it is important to use P. coccineus and P. polyanthus as female parents; this prevents rapid reversal to the recurrent parent P. vulgaris. Although incompatibility barriers are post-zygotic, early hybrid embryo abortion limits the success of F1 crosses. While rescue techniques for globular and early heart-shaped embryos have improved in recent years, -success in hybridization remains very low. In this study, we describe six steps that allowed us to rescue 2-day-old P. vulgaris embryos using a pod culture technique. Our methods consisted of (i) pod culture, (ii) extraction and culture of immature embryos, (iii) dehydration of embryos, (iv) germination of embryos, (v) rooting of developed shoots, and (vi) hardening of plantlets.

  18. TBP-associated factors in Arabidopsis.

    Science.gov (United States)

    Lago, Clara; Clerici, Elena; Mizzi, Luca; Colombo, Lucia; Kater, Martin M

    2004-11-24

    Initiation of transcription mediated by RNA polymerase II requires a number of transcription factors among which TFIID is the major core promoter recognition factor. TFIID is composed of highly conserved factors which include the TATA-binding protein (TBP) and about 14 TBP-associated factors (TAFs). Since TAFs play important roles in transcription they have been extensively studied in organisms like yeast, Drosophila and human. Surprisingly, TAFs have been poorly characterized in plants. With the completion of the Arabidopsis genome sequence, it is possible to search for TAFs, since many of them have conserved amino acid sequences. Mining the genome of Arabidopsis for TAFs resulted in the identification of 18 putative Arabidopsis TAFs (AtTAFs). We have analyzed their protein structure and their genomic localisation. Expression profiling by RT-PCR showed that these TAFs are expressed in all parts of the plant which is in agreement with their general role in transcription. These analyses in combination with their evolutionary conservation with TAFs of other organisms are discussed.

  19. Arabidopsis Seed Mitochondria Are Bioenergetically Active Immediately upon Imbibition and Specialize via Biogenesis in Preparation for Autotrophic Growth.

    Science.gov (United States)

    Paszkiewicz, Gaël; Gualberto, José M; Benamar, Abdelilah; Macherel, David; Logan, David C

    2017-01-01

    Seed germination is a vital developmental transition for production of progeny by sexual reproduction in spermatophytes. Quiescent cells in nondormant dry embryos are reawakened first by imbibition and then by perception of germination triggers. Reanimated tissues enter into a germination program requiring energy for expansion growth. However, germination requires that embryonic tissues develop to support the more energy-demanding processes of cell division and organogenesis of the new seedling. Reactivation of mitochondria to supply the required energy is thus a key process underpinning germination and seedling survival. Using live imaging, we investigated reactivation of mitochondrial bioenergetics and dynamics using Arabidopsis thaliana as a model. Bioenergetic reactivation, visualized by presence of a membrane potential, is immediate upon rehydration. However, reactivation of mitochondrial dynamics only occurs after transfer to germination conditions. Reactivation of mitochondrial bioenergetics is followed by dramatic reorganization of the chondriome (all mitochondrial in a cell, collectively) involving massive fusion and membrane biogenesis to form a perinuclear tubuloreticular structure enabling mixing of previously discrete mitochondrial DNA nucleoids. The end of germination coincides with fragmentation of the chondriome, doubling of mitochondrial number, and heterogeneous redistribution of nucleoids among the mitochondria, generating a population of mitochondria tailored to seedling growth.

  20. Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

    Science.gov (United States)

    Wellner, Karen L.

    2014-01-01

    In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

  1. Arabinan Metabolism during Seed Development and Germination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Leonardo D. Gomez; Clare G. Steele-King; Louise Jones; Jonathan M. Foster; Supachai Vuttipongchaikij; Simon J. McQueen-Mason

    2009-01-01

    Arabinans are found in the pectic network of many cell walls, where, along with galactan, they are present as side chains of Rhamnogalacturonan I. Whilst arabinans have been reported to be abundant polymers in the cell walls of seeds from a range of plant species, their proposed role as a storage reserve has not been thoroughly investigated. In the cell walls of Arabidopsis seeds, arabinose accounts for approximately 40% of the monosaccharide composition of non-cellulosic polysaccharides of embryos. Arabinose levels decline to ~ 15% during seedling establishment, indicating that cell wall arabinans may be mobilized during germination. Immunolocalization of arabinan in embryos, seeds, and seedlings reveals that arabinans accumulate in developing and mature embryos, but disappear during germination and seedling establishment. Experiments using ~(14)C-arabinose show that it is readily incorporated and metabolized in growing seed-lings, indicating an active catabolic pathway for this sugar. We found that depleting arabinans in seeds using a fungal arabinanase causes delayed seedling growth, lending support to the hypothesis that these polymers may help fuel early seedling growth.

  2. Arabidopsis 10-formyl tetrahydrofolate deformylases are essential for photorespiration.

    Science.gov (United States)

    Collakova, Eva; Goyer, Aymeric; Naponelli, Valeria; Krassovskaya, Inga; Gregory, Jesse F; Hanson, Andrew D; Shachar-Hill, Yair

    2008-07-01

    In prokaryotes, PurU (10-formyl tetrahydrofolate [THF] deformylase) metabolizes 10-formyl THF to formate and THF for purine and Gly biosyntheses. The Arabidopsis thaliana genome contains two putative purU genes, At4g17360 and At5g47435. Knocking out these genes simultaneously results in plants that are smaller and paler than the wild type. These double knockout (dKO) mutant plants show a 70-fold increase in Gly levels and accumulate elevated levels of 5- and 10-formyl THF. Embryo development in dKO mutants arrests between heart and early bent cotyledon stages. Mature seeds are shriveled, accumulate low amounts of lipids, and fail to germinate. However, the dKO mutant is only conditionally lethal and is rescued by growth under nonphotorespiratory conditions. In addition, culturing dKO siliques in the presence of sucrose restores normal embryo development and seed viability, suggesting that the seed and embryo development phenotypes are a result of a maternal effect. Our findings are consistent with the involvement of At4g17360 and At5g47435 proteins in photorespiration, which is to prevent excessive accumulation of 5-formyl THF, a potent inhibitor of the Gly decarboxylase/Ser hydroxymethyltransferase complex. Supporting this role, deletion of the At2g38660 gene that encodes the bifunctional 5,10-methylene THF dehydrogenase/5,10-methenyl THF cyclohydrolase that acts upstream of 5-formyl THF formation restored the wild-type phenotype in dKO plants.

  3. An Arabidopsis callose synthase

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole

    2002-01-01

    in the Arabidopsis mpk4 mutant which exhibits systemic acquired resistance (SAR), elevated beta-1,3-glucan synthase activity, and increased callose levels. In addition, AtGsl5 is a likely target of salicylic acid (SA)-dependent SAR, since AtGsl5 mRNA accumulation is induced by SA in wild-type plants, while...... expression of the nahG salicylate hydroxylase reduces AtGsl5 mRNA levels in the mpk4 mutant. These results indicate that AtGsl5 is likely involved in callose synthesis in flowering tissues and in the mpk4 mutant....

  4. AtPEPTIDE RECEPTOR2 mediates the AtPEPTIDE1-induced cytosolic Ca2þ rise, which is required for the suppression of Glutamine Dumper gene expression in Arabidopsis roots

    Institute of Scientific and Technical Information of China (English)

    Chunli Ma; Jie Guo; Yan Kang; Kohei Doman; Anthony C.Bryan; Frans E.Tax; Yube Yamaguchi; Zhi Qi

    2014-01-01

    AtPEPTIDE RECEPTOR2 (AtPEPR2) is a member of leucine-rich repeat receptor-like kinase family and binds to a group of AtPROPEP gene-encoded endogenous peptides, AtPeps. Previously, we found that AtPEPR2 plays a moderate role in the AtPep1-mediated innate immunity responses in Arabidopsis leaf. In this study, we found that AtPEPR2 promoter has strong activity in the vascular tissues of the roots and the atpepr2 mutants showed a moderate but significantly shorter root phenotype. AtPEPR2 partial y mediated AtPep1-induced root elongation inhibition. AtPep1-triggered cytosolic Ca2þ transient rise in roots showed partial dependence on AtPEPR2 and ful y on extracellular Ca2þ ([Ca2þ]ext). Transcriptional profiling analysis found that expression of 75% of AtPep1-modulated genes in roots was ful y dependent on AtPEPR2, of which two dramatical y induced genes showed partial dependence on the [Ca2þ]ext. Arabidopsis genome contains seven Glutamine Dumpers genes (AtGDUs), encoding amino acid exporters. Three of them (AtGDU2, 3, 5) were among the top 10 genes that were downregulated by AtPep1 through AtPEPR2 ful y dependent pathway. Treatment with AtPep1 strongly suppressed pro-moter activity of AtGDU3 in roots, which was relieved by chelating [Ca2þ]ext. Arabidopsis overexpressing AtGDU3 showed a shorter root phenotype and decreased sensitivity to the AtPep1-mediated inhibition of root elongation. Taken together, this study demonstrated a significant role of AtPEPR2 in the AtPep1-mediated signaling in the roots.

  5. Cell wall glucomannan in Arabidopsis is synthesised by CSLA glycosyltransferases, and influences the progression of embryogenesis.

    Science.gov (United States)

    Goubet, Florence; Barton, Christopher J; Mortimer, Jennifer C; Yu, Xiaolan; Zhang, Zhinong; Miles, Godfrey P; Richens, Jenny; Liepman, Aaron H; Seffen, Keith; Dupree, Paul

    2009-11-01

    Mannans are hemicellulosic polysaccharides that have previously been implicated as structural constituents of cell walls and as storage reserves but which may serve other functions during plant growth and development. Several members of the Arabidopsis cellulose synthase-like A (CSLA) family have previously been shown to synthesise mannan polysaccharides in vitro when heterologously expressed. It has also been found that CSLA7 is essential for embryogenesis, suggesting a role for the CSLA7 product in development. To determine whether the CSLA proteins are responsible for glucomannan synthesis in vivo, we characterised insertion mutants in each of the nine Arabidopsis CSLA genes and several double and triple mutant combinations. csla9 mutants showed substantially reduced glucomannan, and triple csla2csla3csla9 mutants lacked detectable glucomannan in stems. Nevertheless, these mutants showed no alteration in stem development or strength. Overexpression of CSLA2, CSLA7 and CSLA9 increased the glucomannan content in stems. Increased glucomannan synthesis also caused defective embryogenesis, leading to delayed development and occasional embryo death. The embryo lethality of csla7 was complemented by overexpression of CSLA9, suggesting that the glucomannan products are similar. We conclude that CSLA2, CSLA3 and CSLA9 are responsible for the synthesis of all detectable glucomannan in Arabidopsis stems, and that CSLA7 synthesises glucomannan in embryos. These results are inconsistent with a substantial role for glucomannan in wall strength in Arabidopsis stems, but indicate that glucomannan levels affect embryogenesis. Together with earlier heterologous expression studies, the glucomannan deficiency observed in csla mutant plants demonstrates that the CSLA family encodes glucomannan synthases.

  6. What is the preimplantation embryo?

    Science.gov (United States)

    Krones, Tanja; Schlüter, Elmar; Neuwohner, Elke; El Ansari, Susan; Wissner, Thomas; Richter, Gerd

    2006-07-01

    We present results from our 'bioethical field studies', which explore and compare the views of experts, patients and the general public on the beginning of human life and the status of the preimplantation embryo in Germany. Using a qualitative and quantitative multi-method approach, we found crucial differences in the categorization of the beginning of human life within the expert group (representative samples of human geneticists n=104, ethicists n=168, midwives n=294, obstetricians n=147, paediatricians n=166), and between expert and lay samples (IVF couples n=108, high genetic risk couples n=324, general population n=1017). The majority of lay respondents as well as paediatricians and obstetricians chose nidation, the moment when the implantation of the fertilized egg into the uterus takes place, as the crucial boundary that marks the beginning of human life, whereas the majority of (female) human geneticists, ethicists and midwives voted for conception as the decisive point in time. The views of all groups on the status of the preimplantation embryo differed from the assumptions underlying German legislation (Embryo Protection Act). Religiousness and religious affiliation, gender, attitudes towards disabled people, post-material values and a present desire for a child were identified as independent factors influencing attitudes towards the preimplantation embryo in the population sample. The results are discussed within a broader philosophical and social science perspective of constructivism versus essentialism, proposing a truly interdisciplinary approach to such bioethical core issues as new reproductive technologies and the status of the preimplantation embryo.

  7. In vivo and in vitro development of Tibetan antelope (Pantholops hodgsonii interspecific cloned embryos

    Directory of Open Access Journals (Sweden)

    Guanghua SU,Lei CHENG,Yu GAO,Kun LIU,Zhuying WEI,Chunling BAI,Fengxia YIN,Li GAO,Guangpeng LI,Shorgan BOU

    2014-02-01

    Full Text Available The Tibetan antelope is endemic to the Tibetan Plateau, China, and is now considered an endangered species. As a possible rescue strategy, the development of embryos constructed by interspecies somatic cell nuclear transfer (iSCNT was examined. Tibetan antelope fibroblast cells were transferred into enucleated bovine, ovine and caprine oocytes. These cloned embryos were then cultured in vitro or in the oviducts of intermediate animals. Less than 0.5% of the reconstructed antelope-bovine embryos cultured in vitro developed to the blastocyst stage. However, when the cloned antelope-bovine embryos were transferred to caprine oviducts, about 1.6% of the embryos developed to the blastocyst stage. In contrast, only 0.7% of the antelope-ovine embryos developed to the morula stage and none developed to blastocysts in ovine oviducts. The treatment of donor cells and bovine oocytes with trichostatin A did not improve the embryo development even when cultured in the oviducts of ovine and caprine. When the antelope-bovine embryos, constructed from oocytes treated with roscovitine or trichostatin A, were cultured in rabbit oviducts 2.3% and 14.3% developed to blastocysts, respectively. It is concluded that although some success was achieved with the protocols used, interspecies cloning of Tibetan antelope presents difficulties still to be overcome. The mechanisms resulting in the low embryo development need investigation and progress might require a deeper understanding of cellular reprogramming.

  8. Oxidative stress and redox regulation on in vitro development of mammalian embryos.

    Science.gov (United States)

    Takahashi, Masashi

    2012-01-01

    Many factors affect development of mammalian preimplantation embryos in vitro. It is well known that in vitro development of bovine embryos is highly affected by culture condition including energy source, growth factors, pH or gas environment. Many efforts have been made towards the suitable environments which can successfully support embryo development in vitro. For a rapid growth and differentiation, embryo requires energy by utilizing ATP, NADPH with oxygen molecules. These energy substrates are produced from the electron transport chain in the mitochondria. In addition to energy production, reactive oxygen species (ROS) are also generated as by-product of such energy production system. ROS production is sensitively controlled by the balance of oxidizing and reducing status and affected by several antioxidant enzymes such as superoxide dismutase (SOD), Catalase, glutathione peroxidase (GPx) or low molecular weight thiols such as glutathione (GSH). Imbalance of oxidation and reduction causes production of excess ROS, which causes the developmental arrest, physical DNA damage, apoptosis induction or lipid peroxidation. Environmental oxygen condition during embryo culture also highly affects embryo development as well as intracellular redox balance. Several studies have revealed that regulation of intra- and extra- cellular reducing environment by reducing excess ROS by using antioxidants, reducing oxygen concentration are effective for improving embryo development. Also, recent studies have demonstrated the difference in gene expression affected by oxidative stress. This review briefly summarizes the effects of ROS and the role of redox balance on preimplantation embryos for improving the efficiency of in vitro production of mammalian embryos.

  9. Studies on lysophosphatidic acid action during in vitro preimplantation embryo development.

    Science.gov (United States)

    Boruszewska, D; Sinderewicz, E; Kowalczyk-Zieba, I; Grycmacher, K; Woclawek-Potocka, I

    2016-01-01

    Assisted reproductive technologies, including in vitro embryo production (IVP), have been successfully used in animal reproduction to optimize breeding strategies for improved production and health in animal husbandry. Despite the progress in IVP techniques over the years, further improvements in in vitro embryo culture systems are required for the enhancement of oocyte and embryo developmental competence. One of the most important issues associated with IVP procedures is the optimization of the in vitro culture of oocytes and embryos. Studies in different species of animals and in humans have identified important roles for receptor-mediated lysophosphatidic acid (LPA) signaling in multiple aspects of human and animal reproductive tract function. The data on LPA signaling in the ovary and uterus suggest that LPA can directly contribute to embryo-maternal interactions via its influence on early embryo development beginning from the influence of the ovarian environment on the oocyte to the influence of the uterine environment on the preimplantation embryo. This review discusses the current status of LPA as a potential supplement in oocyte maturation, fertilization, and embryo culture media and current views on the potential involvement of the LPA signaling pathway in early embryo development.

  10. Alternation of apoptotic and implanting genes expression of mouse embryos after re-vitrification

    Science.gov (United States)

    Majidi Gharenaz, Nasrin; Movahedin, Mansoureh; Mazaheri, Zohreh; Pour beiranvand, Shahram

    2016-01-01

    Background: Nowadays, oocytes and embryos vitrification has become a routine technique. Based on clinical judgment, re-vitrification maybe required. But little is known about re-vitrification impact on genes expression. Objective: The impact of re-vitrification on apoptotic and implanting genes, Bax, Bcl-2 and ErbB4, at compaction stage embryos were evaluated in this study. Materials and Methods: In this experimental study, 8 cell embryos (n=240) were collected from female mature mice, 60-62 hr post HCG injection. The embryos were divided randomly to 3 groups included: fresh (n=80), vitrified at 8 cell stage (n=80), vitrified at 8 cell stage thawed and re-vitrified at compaction stage (n=80). Embryos were vitrified by using cryolock, (open system) described by Kuwayama. Q-PCR was used to examine the expression of Bax, Bcl2 ErbB4 genes in derived blastocysts. Results: Our result showed that expanded blastocyst rate was similar between vitrified and re-vitrified groups, while re-vitrified embryos showed significant decrease in expanded blastocyst rate comparing with fresh embryos (p=0.03). In addition, significant difference was observed on apoptotic gene expression when comparing re-vitrified and fresh embryos (p=0.004), however expression of Bax and Bcl-2 (apoptotic) genes didn't demonstrate a significant difference between re-vitrified and vitrified groups. The expression rate of ErbB4, an implantation gene was decreased in re-vitrified embryos comparing with fresh embryos (p=0.003), but it was similar between re-vitrified and vitrified embryos. Conclusion: Re-vitrification can alter the expression of Bax, Bcl-2 and ErbB4 genes and developmental rate of mouse embryos in compaction stage. PMID:27679826

  11. Ex Ovo Model for Directly Visualizing Chick Embryo Development

    Science.gov (United States)

    Dorrell, Michael I.; Marcacci, Michael; Bravo, Stephen; Kurz, Troy; Tremblay, Jacob; Rusing, Jack C.

    2012-01-01

    We describe a technique for removing and growing chick embryos in culture that utilizes relatively inexpensive materials and requires little space. It can be readily performed in class by university, high school, or junior high students, and teachers of any grade level should be able to set it up for their students. Students will be able to…

  12. Proteomics of early zebrafish embryos

    Directory of Open Access Journals (Sweden)

    Heisenberg Carl-Philipp

    2006-01-01

    Full Text Available Abstract Background Zebrafish (D. rerio has become a powerful and widely used model system for the analysis of vertebrate embryogenesis and organ development. While genetic methods are readily available in zebrafish, protocols for two dimensional (2D gel electrophoresis and proteomics have yet to be developed. Results As a prerequisite to carry out proteomic experiments with early zebrafish embryos, we developed a method to efficiently remove the yolk from large batches of embryos. This method enabled high resolution 2D gel electrophoresis and improved Western blotting considerably. Here, we provide detailed protocols for proteomics in zebrafish from sample preparation to mass spectrometry (MS, including a comparison of databases for MS identification of zebrafish proteins. Conclusion The provided protocols for proteomic analysis of early embryos enable research to be taken in novel directions in embryogenesis.

  13. Cell adhesion in embryo morphogenesis.

    Science.gov (United States)

    Barone, Vanessa; Heisenberg, Carl-Philipp

    2012-02-01

    Visualizing and analyzing shape changes at various scales, ranging from single molecules to whole organisms, are essential for understanding complex morphogenetic processes, such as early embryonic development. Embryo morphogenesis relies on the interplay between different tissues, the properties of which are again determined by the interaction between their constituent cells. Cell interactions, on the other hand, are controlled by various molecules, such as signaling and adhesion molecules, which in order to exert their functions need to be spatiotemporally organized within and between the interacting cells. In this review, we will focus on the role of cell adhesion functioning at different scales to organize cell, tissue and embryo morphogenesis. We will specifically ask how the subcellular distribution of adhesion molecules controls the formation of cell-cell contacts, how cell-cell contacts determine tissue shape, and how tissue interactions regulate embryo morphogenesis.

  14. The LysM Receptor-Like Kinase LysM RLK1 Is Required to Activate Defense and Abiotic-Stress Responses Induced by Overexpression of Fungal Chitinases in Arabidopsis Plants

    Institute of Scientific and Technical Information of China (English)

    Yariv Brotman; Ada Viterbo; Udi Landau; Smadar Pnini; Jan Lisec; Salma Balazadeh; Bernd Mueller-Roeber; Aviah Zilberstein; Lothar Willmitzer; Ilan Chet

    2012-01-01

    Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased tolerance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinase1 (CERK1/LysM RLK1) gene,known to play a critical role in signaling defense responses induced by exogenous chitin.Arabidopsis plants overexpressing the endochitinase chit36 and hexoaminidase excy1 genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity,heavy-metal stresses,and Botrytis cinerea infection.Resistant lines,overexpressing fungal chitinases at different levels,were outcrossed to lysm rlk1 mutants.Independent homozygous hybrids lost resistance to biotic and abiotic stresses,despite enhanced chitinase activity.Expression analysis of 270 stress-related genes,including those induced by reactive oxygen species (ROS) and chitin,revealed constant up-regulation (at least twofold) of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlk1 knockout mutant or the hybrids harboring the mutation.These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.

  15. In amnio MRI of mouse embryos.

    Directory of Open Access Journals (Sweden)

    Thomas A Roberts

    Full Text Available Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is retained in the amniotic sac and demonstrate how important embryonic structures can be visualised in 3D with high spatial resolution (100 µm/px. To illustrate the utility of in amnio imaging, we subsequently apply the technique to examine abnormal mouse embryos with abdominal wall defects. Mouse embryos at E17.5 were imaged and compared, including three normal phenotype embryos, an abnormal embryo with a clear exomphalos defect, and one with a suspected gastroschisis phenotype. Embryos were excised from the mother ensuring the amnion remained intact and stereo microscopy was performed. Embryos were next embedded in agarose for 3D, high resolution MRI on a 9.4T scanner. Identification of the abnormal embryo phenotypes was not possible using stereo microscopy or conventional ex vivo MRI. Using in amnio MRI, we determined that the abnormal embryos had an exomphalos phenotype with varying severities. In amnio MRI is ideally suited to investigate the complex relationship between embryo and amnion, together with screening for other abnormalities located outside of the mouse embryo, providing a valuable complement to histology and existing imaging methods available to the phenotyping community.

  16. ‘Vanishing embryo syndrome’ in IVF/ICSI

    DEFF Research Database (Denmark)

    Hvidtjørn, Dorte; Grove, Jakob; Schendel, Diana

    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...... 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...

  17. Improving production of Zebra Fish Embryos in the lab

    DEFF Research Database (Denmark)

    Thomsen, Jens Peter; Adu, Robert Ohene

    2011-01-01

    in the 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...... 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....

  18. Reference: 6 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available 6 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u11756663i Torres Migue...l Angel et al. 2002 Jan. Proc. Natl. Acad. Sci. U.S.A. 99(1):517-22. Reactive oxygen intermediates (ROI) are... strongly associated with plant defense responses. The origin of these ROI has been controversial. Arabidopsis re... role in ROI generation. We analyzed lines carrying dSpm insertions in the highly expressed AtrbohD and AtrbohF genes. Both are re...quired for full ROI production observed during incompatible interactions with the bact

  19. Reference: 651 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available naud et al. 2007 Sep. EMBO J. 26(18):4126-37. The initiation of meiotic recombination by the formation of DNA double-strand bre...aks (DSBs) catalysed by the Spo11 protein is strongly evolutionary conserved. In Saccharomyces cere...visiae, Spo11 requires nine other proteins for meiotic DSB formation, b...ut, unlike Spo11, few of these proteins seem to be conserved across kingdoms. In order to investigate this re...in Arabidopsis thaliana. In Atprd1 mutants, meiotic recombination rates fall dramatically, early re

  20. Reference: 3 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available t al. 2001 Jul. Plant J. 27(2):89-99. We isolated an Arabidopsis lesion initiation 2 (lin2) mutant, which develops lesion...droxylase (nahG) gene. This suggests that the lesion formation triggered in lin2 plants is determined prior ...to or independently of the accumulation of SA but that the accumulation is required to limit the spread of lesion...s in lin2 plants. A deficiency of coproporphyrinogen III oxidase causes lesion...s, usually activated by pathogen infection. These results demonstrate that a porphyrin pathway impairment is responsible for the lesi

  1. Reference: 387 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available Michael F et al. 2006 Jul. Plant Physiol. 141(3):957-65. Karyogamy, or nuclear fusion, is essential for sex...ual reproduction. In angiosperms, karyogamy occurs three times: twice during double fertilization of the egg...e two polar nuclei fuse to form the diploid central cell nucleus. The molecular mechanisms controlling karyoga...etected during megagametogenesis. nfd1 is also affected in karyogamy during double fertilization. Using tran...odes the Arabidopsis RPL21M protein and is required for karyogamy during female g

  2. SHORT-ROOT and SCARECROW regulate leaf growth in Arabidopsis by stimulating S-phase progression of the cell cycle.

    NARCIS (Netherlands)

    Dhondt, S.; Coppens, F.; Winter, F. de; Swarup, K.; Merks, R.M.H.; Inze, D.; Bennett, M.J.; Beemster, G.T.S.

    2010-01-01

    SHORT-ROOT (SHR) and SCARECROW (SCR) are required for stem cell maintenance in the Arabidopsis (Arabidopsis thaliana) root meristem, ensuring its indeterminate growth. Mutation of SHR and SCR genes results in disorganization of the quiescent center and loss of stem cell activity, resulting in the ce

  3. Embryo-scale tissue mechanics during Drosophila gastrulation movements

    Science.gov (United States)

    Rauzi, Matteo; Krzic, Uros; Saunders, Timothy E.; Krajnc, Matej; Ziherl, Primož; Hufnagel, Lars; Leptin, Maria

    2015-01-01

    Morphogenesis of an organism requires the development of its parts to be coordinated in time and space. While past studies concentrated on defined cell populations, a synthetic view of the coordination of these events in a whole organism is needed for a full understanding. Drosophila gastrulation begins with the embryo forming a ventral furrow, which is eventually internalized. It is not understood how the rest of the embryo participates in this process. Here we use multiview selective plane illumination microscopy coupled with infrared laser manipulation and mutant analysis to dissect embryo-scale cell interactions during early gastrulation. Lateral cells have a denser medial–apical actomyosin network and shift ventrally as a compact cohort, whereas dorsal cells become stretched. We show that the behaviour of these cells affects furrow internalization. A computational model predicts different mechanical properties associated with tissue behaviour: lateral cells are stiff, whereas dorsal cells are soft. Experimental analysis confirms these properties in vivo. PMID:26497898

  4. Phenotype classification of zebrafish embryos by supervised learning.

    Science.gov (United States)

    Jeanray, Nathalie; Marée, Raphaël; Pruvot, Benoist; Stern, Olivier; Geurts, Pierre; Wehenkel, Louis; Muller, Marc

    2015-01-01

    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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Nils Klüver

    Full Text Available 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

  7. Embryo temperature during incubation: practice and theory

    NARCIS (Netherlands)

    Lourens, A.

    2008-01-01

    (Key words: incubation, embryo temperature, embryonic development, heat production, heat loss) Until recently, all incubator studies were performed using a constant machine temperature (MT). But it is embryo temperature (ET) that is of importance to the embryo, and not MT. In practice, MT is often

  8. Improving embryo quality in assisted reproduction

    NARCIS (Netherlands)

    Mantikou, E.

    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

  9. Analysis of chlorophyll fluorescence reveals stage specific patterns of chloroplast-containing cells during Arabidopsis embryogenesis.

    Science.gov (United States)

    Tejos, Ricardo I; Mercado, Ana V; Meisel, Lee A

    2010-01-01

    The basic body plan of a plant is established early in embryogenesis when cells differentiate, giving rise to the apical and basal regions of the embryo. Using chlorophyll fluorescence as a marker for chloroplasts, we have detected specific patterns of chloroplast-containing cells at specific stages of embryogenesis. Non-randomly distributed chloroplast-containing cells are seen as early as the globular stage of embryogenesis in Arabidopsis. In the heart stage of embryogenesis, chloroplast containing cells are detected in epidermal cells as well as a central region of the heart stage embryo, forming a triangular septum of chloroplast-containing cells that divides the embryo into three equal sectors. Torpedo stage embryos have chloroplast-containing epidermal cells and a central band of chloroplast-containing cells in the cortex layer, just below the shoot apical meristem. In the walking-stick stage of embryogenesis, chloroplasts are present in the epidermal, cortex and endodermal cells. The chloroplasts appear reduced or absent from the provascular and columella cells of walking-stick stage embryos. These results suggest that there is a tight regulation of plastid differentiation during embryogenesis that generates specific patterns of chloroplast-containing cells in specific cell layers at specific stages of embryogenesis.

  10. Reference: 774 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available an essential gene, the disruption of which causes embryonic lethality. Plants carrying a hypomorphic smg7 mu...e progression from anaphase to telophase in the second meiotic division in Arabidopsis. Arabidopsis SMG7 is

  11. Reference: 398 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available plays attenuated chloroplast movements under intermediate and high light intensitie...hese movements. In this work, we describe plastid movement impaired 2 (pmi2), a mutant in Arabidopsis (Arabidopsis thaliana) that dis

  12. Reference: 173 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available mical approaches to elucidate the action mechanisms of sirtinol in Arabidopsis. A...tic and chemical analyses of the action mechanisms of sirtinol in Arabidopsis. 8 3129-34 15710899 2005 Feb P

  13. Reference: 718 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available displayed a moderate but significant decrease in germination in the presence of D...NA damage. This report links Ubc13-Uev with functions in DNA damage response in Arabidopsis. Arabidopsis UEV

  14. Arabidopsis CDS blastp result: AK068856 [KOME

    Lifescience Database Archive (English)

    Full Text Available eme oxygenase (HY1) [Arabidopsis thaliana] GI:4877362, heme oxygenase 1 [Arabidopsis thaliana] GI:4530591 GB:AF132475; annotation upd...ated per Seth J. Davis at University of Wisconsin-Madison 3e-90 ...

  15. Arabidopsis CDS blastp result: AK104955 [KOME

    Lifescience Database Archive (English)

    Full Text Available B:AF132475; annotation updated per Seth J. Davis at University of Wisconsin-Madison 3e-90 ... ...heme oxygenase (HY1) [Arabidopsis thaliana] GI:4877362, heme oxygenase 1 [Arabidopsis thaliana] GI:4530591 G

  16. Reference: 110 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available on process. Our study shows that an Arabidopsis SNM protein, although structurally closer to the SNM1/PSO2 members, shares some prope...rties with ARTEMIS but also has novel characteristics. Arabidopsis plants defective

  17. Exportin1 genes are essential for development and function of the gametophytes in Arabidopsis thaliana.

    Science.gov (United States)

    Blanvillain, Robert; Boavida, Leonor C; McCormick, Sheila; Ow, David W

    2008-11-01

    Gametes are produced in plants through mitotic divisions in the haploid gametophytes. We investigated the role of EXPORTIN1 (XPO1) genes during the development of both female and male gametophytes of Arabidopsis. Exportins exclude target proteins from the nucleus and are also part of a complex recruited at the kinetochores during mitosis. Here we show that double mutants in Arabidopsis XPO1A and XPO1B are gametophytic defective. In homozygous-heterozygous plants, 50% of the ovules were arrested at different stages according to the parental genotype. Double-mutant female gametophytes of xpo1a-3/+; xpo1b-1/xpo1b-1 plants failed to undergo all the mitotic divisions or failed to complete embryo sac maturation. Double-mutant female gametophytes of xpo1a-3/xpo1a-3; xpo1b-1/+ plants had normal mitotic divisions and fertilization occurred; in most of these embryo sacs the endosperm started to divide but an embryo failed to develop. Distortions in male transmission correlated with the occurrence of smaller pollen grains, poor pollen germination, and shorter pollen tubes. Our results show that mitotic divisions are possible without XPO1 during the haploid phase, but that XPO1 is crucial for the maternal-to-embryonic transition.

  18. A Simple Method for Transportation of Mouse Embryos Using Microtubes and a Warm Box.

    Science.gov (United States)

    Tokoro, Mikiko; Fukunaga, Noritaka; Yamanaka, Kaori; Itoi, Fumiaki; Terashita, Yukari; Kamada, Yuko; Wakayama, Sayaka; Asada, Yoshimasa; Wakayama, Teruhiko

    2015-01-01

    Generally, transportation of preimplantation embryos without freezing requires incubators that can maintain an optimal culture environment with a suitable gas phase, temperature, and humidity. Such incubators are expensive to transport. We reported previously that normal offspring were obtained when the gas phase and temperature could be maintained during transportation. However, that system used plastic dishes for embryo culture and is unsuitable for long-distance transport of live embryos. Here, we developed a simple low-cost embryo transportation system. Instead of plastic dishes, several types of microtubes-usually used for molecular analysis-were tested for embryo culture. When they were washed and attached to a gas-permeable film, the rate of embryo development from the 1-cell to blastocyst stage was more than 90%. The quality of these blastocysts and the rate of full-term development after embryo transfer to recipient female mice were similar to those of a dish-cultured control group. Next, we developed a small warm box powered by a battery instead of mains power, which could maintain an optimal temperature for embryo development during transport. When 1-cell embryos derived from BDF1, C57BL/6, C3H/He and ICR mouse strains were transported by a parcel-delivery service over 3 days using microtubes and the box, they developed to blastocysts with rates similar to controls. After the embryos had been transferred into recipient female mice, healthy offspring were obtained without any losses except for the C3H/He strain. Thus, transport of mouse embryos is possible using this very simple method, which might prove useful in the field of reproductive medicine.

  19. A Simple Method for Transportation of Mouse Embryos Using Microtubes and a Warm Box.

    Directory of Open Access Journals (Sweden)

    Mikiko Tokoro

    Full Text Available Generally, transportation of preimplantation embryos without freezing requires incubators that can maintain an optimal culture environment with a suitable gas phase, temperature, and humidity. Such incubators are expensive to transport. We reported previously that normal offspring were obtained when the gas phase and temperature could be maintained during transportation. However, that system used plastic dishes for embryo culture and is unsuitable for long-distance transport of live embryos. Here, we developed a simple low-cost embryo transportation system. Instead of plastic dishes, several types of microtubes-usually used for molecular analysis-were tested for embryo culture. When they were washed and attached to a gas-permeable film, the rate of embryo development from the 1-cell to blastocyst stage was more than 90%. The quality of these blastocysts and the rate of full-term development after embryo transfer to recipient female mice were similar to those of a dish-cultured control group. Next, we developed a small warm box powered by a battery instead of mains power, which could maintain an optimal temperature for embryo development during transport. When 1-cell embryos derived from BDF1, C57BL/6, C3H/He and ICR mouse strains were transported by a parcel-delivery service over 3 days using microtubes and the box, they developed to blastocysts with rates similar to controls. After the embryos had been transferred into recipient female mice, healthy offspring were obtained without any losses except for the C3H/He strain. Thus, transport of mouse embryos is possible using this very simple method, which might prove useful in the field of reproductive medicine.

  20. Influence of "Solcoseryl" during culture on the sex-dependent repair of bovine demi-embryos.

    Science.gov (United States)

    Tominaga, K; Yoneda, K; Utsumi, K

    1996-03-01

    The purpose of this experiment was to determine the effect of culture conditions on the development of split embryos after bisection and on the sex ratio of resultant bovine demi-embryos. Embryos that had developed into blastocysts on days 6 1/2 to 7 or on days 7 1/2 to 8 from oocytes matured and fertilized in vitro were bisected in BMOC-3 medium supplemented with 33% calf serum. The medium also contained 0%, 0.1% or 1.0% Solcoseryl, a deproteinized hemodialysate product from calf blood. The demi-embryos were first cultured for 4 hours in the same medium in which they had been bisected and then co-cultured with cumulus cells in TCM199 supplemented with 1% calf serum for an additional 20 hr. The rate of production of good to excellent quality demi-embryos obtained from days 6 1/2 to 7 blastocysts was higher than from those on days 7 1/2 to 8. The rate was also significantly improved when blastocysts were bisected in medium containing 0.1% or 1.0% Solcoseryl, compared to the medium without Solcoseryl. Male embryos seemed to recover more rapidly than female embryos, as assessed by morphological quality at 4 hr, although the quality of female embryos had improved by 24 hr. The percentage of males after culture was higher in the medium without Solcoseryl than in its presence. Thus, addition of Solcoseryl at either 0.1% or 1.0% to BMOC-3 medium seemed to improve the production efficiency of good quality demi-embryos, but did not influence the sex ratio. It appears as if female demi-embryos required more time than male embryos to be repaired after bisection.

  1. Role of the Arabidopsis PIN6 Auxin Transporter in Auxin Homeostasis and Auxin-Mediated Development

    OpenAIRE

    2013-01-01

    Plant-specific PIN-formed (PIN) efflux transporters for the plant hormone auxin are required for tissue-specific directional auxin transport and cellular auxin homeostasis. The Arabidopsis PIN protein family has been shown to play important roles in developmental processes such as embryogenesis, organogenesis, vascular tissue differentiation, root meristem patterning and tropic growth. Here we analyzed roles of the less characterised Arabidopsis PIN6 auxin transporter. PIN6 is auxin-inducible...

  2. Rhesus monkey embryos produced by nuclear transfer from embryonic blastomeres or somatic cells.

    Science.gov (United States)

    Mitalipov, Shoukhrat M; Yeoman, Richard R; Nusser, Kevin D; Wolf, Don P

    2002-05-01

    Production of genetically identical nonhuman primates would reduce the number of animals required for biomedical research and dramatically impact studies pertaining to immune system function, such as development of the human-immunodeficiency-virus vaccine. Our long-term goal is to develop robust somatic cell cloning and/or twinning protocols in the rhesus macaque. The objective of this study was to determine the developmental competence of nuclear transfer (NT) embryos derived from embryonic blastomeres (embryonic cell NT) or fetal fibroblasts (somatic cell NT) as a first step in the production of rhesus monkeys by somatic cell cloning. Development of cleaved embryos up to the 8-cell stage was similar among embryonic and somatic cell NT embryos and comparable to controls created by intracytoplasmic sperm injection (ICSI; mean +/- SEM, 81 +/- 5%, 88 +/- 7%, and 87 +/- 4%, respectively). However, significantly lower rates of development to the blastocyst stage were observed with somatic cell NT embryos (1%) in contrast to embryonic cell NT (34 +/- 15%) or ICSI control embryos (46 +/- 6%). Development of somatic cell NT embryos was not markedly affected by donor cell treatment, timing of activation, or chemical activation protocol. Transfer of embryonic, but not of somatic cell NT embryos, into recipients resulted in term pregnancy. Future efforts will focus on optimizing the production of somatic cell NT embryos that develop in high efficiency to the blastocyst stage in vitro.

  3. 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.

  4. Handling Arabidopsis plants: growth, preservation of seeds, transformation, and genetic crosses.

    Science.gov (United States)

    Rivero, Luz; Scholl, Randy; Holomuzki, Nicholas; Crist, Deborah; Grotewold, Erich; Brkljacic, Jelena

    2014-01-01

    Growing healthy plants is essential for the advancement of Arabidopsis thaliana (Arabidopsis) research. Over the last 20 years, the Arabidopsis Biological Resource Center (ABRC) has collected and developed a series of best-practice protocols, some of which are presented in this chapter. Arabidopsis can be grown in a variety of locations, growth media, and environmental conditions. Most laboratory accessions and their mutant or transgenic derivatives flower after 4-5 weeks and set seeds after 7-8 weeks, under standard growth conditions (soil, long day, 23 ºC). Some mutant genotypes, natural accessions, and Arabidopsis relatives require strict control of growth conditions best provided by growth rooms, chambers, or incubators. Other lines can be grown in less-controlled greenhouse settings. Although the majority of lines can be grown in soil, certain experimental purposes require utilization of sterile solid or liquid growth media. These include the selection of primary transformants, identification of homozygous lethal individuals in a segregating population, or bulking of a large amount of plant material. The importance of controlling, observing, and recording growth conditions is emphasized and appropriate equipment required to perform monitoring of these conditions is listed. Proper conditions for seed harvesting and preservation, as well as seed quality control, are also described. Plant transformation and genetic crosses, two of the methods that revolutionized Arabidopsis genetics, are introduced as well.

  5. Electroporation into Cultured Mammalian Embryos

    Science.gov (United States)

    Nomura, Tadashi; Takahashi, Masanori; Osumi, Noriko

    Over the last century, mammalian embryos have been used extensively as a common animal model to investigate fundamental questions in the field of developmental biology. More recently, the establishment of transgenic and gene-targeting systems in laboratory mice has enabled researchers to unveil the genetic mechanisms under lying complex developmental processes (Mak, 2007). However, our understanding of cell—cell interactions and their molecular basis in the early stages of mammalian embryogenesis is still very fragmentary. One of the major problems is the difficulty of precise manipulation and limited accessibility to mammalian embryos via uterus wall. Unfortunately, existing tissue and organotypic culture systems per se do not fully recapitulate three-dimensional, dynamic processes of organogenesis observed in vivo. Although transgenic animal technology and virus-mediated gene delivery are useful to manipulate gene expression, these techniques take much time and financial costs, which limit their use.

  6. 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.

  7. 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.

  8. 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.

  9. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...... (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar...... to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since...

  10. Chromosomal proteins of Arabidopsis thaliana.

    Science.gov (United States)

    Moehs, C P; McElwain, E F; Spiker, S

    1988-07-01

    In plants with large genomes, each of the classes of the histones (H1, H2A, H2B, H3 and H4) are not unique polypeptides, but rather families of closely related proteins that are called histone variants. The small genome and preponderance of single-copy DNA in Arabidopsis thaliana has led us to ask if this plant has such families of histone variants. We have thus isolated histones from Arabidopsis and analyzed them on four polyacrylamide gel electrophoretic systems: an SDS system; an acetic acid-urea system; a Triton transverse gradient system; and a two-dimensional system combining SDS and Triton-acetic acid-urea systems. This approach has allowed us to identify all four of the nucleosomal core histones in Arabidopsis and to establish the existence of a set of H2A and H2B variants. Arabidopsis has at least four H2A variants and three H2B variants of distinct molecular weights as assessed by electrophoretic mobility on SDS-polyacrylamide gels. Thus, Arabidopsis displays a diversity in these histones similar to the diversity displayed by plants with larger genomes such as wheat.The high mobility group (HMG) non-histone chromatin proteins have attracted considerable attention because of the evidence implicating them as structural proteins of transcriptionally active chromatin. We have isolated a group of non-histone chromatin proteins from Arabidopsis that meet the operational criteria to be classed as HMG proteins and that cross-react with antisera to HMG proteins of wheat.

  11. Ubiquitin-related modifiers of Arabidopsis thaliana influence root development.

    Directory of Open Access Journals (Sweden)

    Florian John

    Full Text Available Ubiquitins are small peptides that allow for posttranslational modification of proteins. Ubiquitin-related modifier (URM proteins belong to the class of ubiquitin-like proteins. A primary function of URM proteins has been shown to be the sulfur transfer reaction leading to thiolation of tRNAs, a process that is important for accurate and effective protein translation. Recent analyses revealed that the Arabidopsis genome codes for two URM proteins, URM11 and URM12, which both are active in the tRNA thiolation process. Here, we show that URM11 and URM12 have overlapping expression patterns and are required for tRNA thiolation. The characterization of urm11 and urm12 mutants reveals that the lack of tRNA thiolation induces changes in general root architecture by influencing the rate of lateral root formation. In addition, they synergistically influence root hair cell growth. During the sulfur transfer reaction, URM proteins of different organisms interact with a thiouridylase, a protein-protein interaction that also takes place in Arabidopsis, since URM11 and URM12 interact with the Arabidopsis thiouridylase ROL5. Hence, the sulfur transfer reaction is conserved between distantly related species such as yeast, humans, and plants, and in Arabidopsis has an impact on root development.

  12. Polyploidization increases meiotic recombination frequency in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Rehmsmeier Marc

    2011-04-01

    Full Text Available Abstract Background Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination. Results Using two genetically linked transgenes providing seed-specific fluorescence, we compared a high number of progeny from diploid and tetraploid Arabidopsis plants. We show that rates of meiotic recombination in reciprocal crosses of genetically identical diploid and autotetraploid Arabidopsis plants were significantly higher in tetraploids compared to diploids. Although male and female gametogenesis differ substantially in meiotic recombination frequency, both rates were equally increased in tetraploids. To investigate whether multivalent formation in autotetraploids was responsible for the increased recombination rates, we also performed corresponding experiments with allotetraploid plants showing strict bivalent pairing. We found similarly increased rates in auto- and allotetraploids, suggesting that the ploidy effect is independent of chromosome pairing configurations. Conclusions The evolutionary success of polyploid plants in nature and under domestication has been attributed to buffering of mutations and sub- and neo-functionalization of duplicated genes. Should the data described here be representative for polyploid plants, enhanced meiotic recombination, and the resulting rapid creation of genetic diversity, could have also contributed to their prevalence.

  13. 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.

  14. Cellular differentiation regulated by gibberellin in the Arabidopsis thaliana pickle mutant

    Energy Technology Data Exchange (ETDEWEB)

    Ogas, J.; Somerville, C. [Carnegie Institution of Washington, Stanford, CA (United States); Cheng, Jin-Chen; Sung, R. [Univ. of California, Berkeley, CA (United States)

    1997-07-04

    The plant growth regulator gibberellin (GA) has a profound effect on shoot development and promotes developmental transitions such as flowering. Little is known about any analogous effect GA might have on root development. In a screen for mutants, Arabi-dopsis plants carrying a mutation designated pickle (pkl) were isolated in which the primary root meristem retained characteristics of embryonic tissue. Expression of this aberrant differentiation state was suppressed by GA. Root tissue from plants carrying the pkl mutation spontaneously regenerated new embryos and plants. 19 refs., 3 figs., 1 tab.

  15. 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

    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......-four blastocysts transferred to 45 patients resulted in 48.9% clinical pregnancy rates including 8 twin, 8 single, 5 miscarriages and 1 ectopic pregnancies. Our results indicate that the WOW system means a promising alternative of microdrops for culture of mammalian embryos including human...

  16. 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...

  17. Nucleolar remodeling in nuclear transfer embryos

    DEFF Research Database (Denmark)

    Laurincik, Jozef; Maddox-Hyttel, Poul

    2007-01-01

    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...... 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...... 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...

  18. Evaluation of Bovine Embryo Biopsy Techniques according to Their Ability to Preserve Embryo Viability

    Directory of Open Access Journals (Sweden)

    M. Cenariu

    2012-01-01

    Full Text Available The purpose of this research was to evaluate three embryo biopsy techniques used for preimplantation genetic diagnosis (PGD in cattle and to recommend the least invasive one for current use, especially when PGD is followed by embryo cryopreservation. Three hundred bovine embryos were biopsied by either one of the needle, aspiration or microblade method, and then checked for viability by freezing/thawing and transplantation to recipient cows. The number of pregnancies obtained after the transfer of biopsied frozen/thawed embryos was assessed 30 days later using ultrasounds. The results were significantly different between the three biopsy methods: the pregnancy rate was of 57% in cows that received embryos biopsied by needle, 43% in cows that received embryos biopsied by aspiration, and 31% in cows that received embryos biopsied by microblade. Choosing an adequate biopsy method is therefore of great importance in embryos that will undergo subsequent cryopreservation, as it significantly influences their viability after thawing.

  19. Embryo forming cells in carrot suspension cultures.

    OpenAIRE

    Toonen, M.A.J.

    1997-01-01

    Somatic cells of many plant species can be cultured in vitro and induced to form embryos that are able to develop into mature plants. This process, termed somatic embryogenesis, was originally described in carrot (Daucus carota L.). Somatic embryos develop through the same characteristic morphological stages, i.e. the globular-, heartand torpedo-stage respectively, as their zygotic counterparts. Due to the different cellular origin of somatic embryos, it is less clear to what extent the earli...

  20. Facial Transplants in Xenopus laevis Embryos

    OpenAIRE

    Jacox, Laura A.; Dickinson, Amanda J.; Sive, Hazel

    2014-01-01

    Craniofacial birth defects occur in 1 out of every 700 live births, but etiology is rarely known due to limited understanding of craniofacial development. To identify where signaling pathways and tissues act during patterning of the developing face, a 'face transplant' technique has been developed in embryos of the frog Xenopus laevis. A region of presumptive facial tissue (the "Extreme Anterior Domain" (EAD)) is removed from a donor embryo at tailbud stage, and transplanted to a host embryo ...

  1. 9 CFR 98.16 - The embryo collection unit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may...

  2. Generation and developmental characteristics of porcine tetraploid embryos and tetraploid/diploid chimeric embryos.

    Science.gov (United States)

    He, Wenteng; Kong, Qingran; Shi, Yongqian; Xie, Bingteng; Jiao, Mingxia; Huang, Tianqing; Guo, Shimeng; Hu, Kui; Liu, Zhonghua

    2013-10-01

    The aim of this study was to optimize electrofusion conditions for generating porcine tetraploid (4n) embryos and produce tetraploid/diploid (4n/2n) chimeric embryos. Different electric field intensities were tested and 2 direct current (DC) pulses of 0.9 kV/cm for 30 μs was selected as the optimum condition for electrofusion of 2-cell embryos to produce 4n embryos. The fusion rate of 2-cell embryos and the development rate to blastocyst of presumably 4n embryos, reached 85.4% and 28.5%, respectively. 68.18% of the fused embryos were found to be 4n as demonstrated by fluorescent in situ hybridization (FISH). Although the number of blastomeres in 4n blastocysts was significantly lower than in 2n blastocysts (P0.05), suggesting that the blastocyst forming capacity in 4n embryos is similar to those in 2n embryos. Moreover, 4n/2n chimeric embryos were obtained by aggregation of 4n and 2n embryos. We found that the developmental rate and cell number of blastocysts of 4-cell (4n)/4-cell (2n) chimeric embryos were significantly higher than those of 2-cell (4n)/4-cell (2n), 4-cell (4n)/8-cell (2n), 4-cell (4n)/2-cell (2n) chimeric embryos (P<0.05). Consistent with mouse chimeras, the majority of 4n cells contribute to the trophectoderm (TE), while the 2n cells are mainly present in the inner cell mass (ICM) of porcine 4n/2n chimeric embryos. Our study established a feasible and efficient approach to produce porcine 4n embryos and 4n/2n chimeric embryos.

  3. Transmission of Campylobacter coli in chicken embryos

    Directory of Open Access Journals (Sweden)

    Daise Aparecida Rossi

    2012-06-01

    Full Text Available Campylobacter coli is an important species involved in human cases of enteritis, and chickens are carriers of the pathogen mainly in developing country. The current study aimed to evaluate the transmission of C. coli and its pathogenic effects in chicken embryos. Breeder hens were inoculated intra-esophageally with C. coli isolated from chickens, and their eggs and embryos were analyzed for the presence of bacteria using real-time PCR and plate culture. The viability of embryos was verified. In parallel, SPF eggs were inoculated with C. coli in the air sac; after incubation, the embryos were submitted to the same analysis as the embryos from breeder hens. In embryos and fertile eggs from breeder hens, the bacterium was only identified by molecular methods; in the SPF eggs, however, the bacterium was detected by both techniques. The results showed no relationship between embryo mortality and positivity for C. coli in the embryos from breeder hens. However, the presence of bacteria is a cause of precocious mortality for SPF embryos. This study revealed that although the vertical transmission is a possible event, the bacteria can not grow in embryonic field samples.

  4. Nano-nutrition of chicken embryos

    DEFF Research Database (Denmark)

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

    2013-01-01

    It has been suggested that the quantity and quality of nutrients stored in the egg might not be optimal for the fast rate of chicken embryo development in modern broilers, and embryos could be supplemented with nutrients by in ovo injection. Recent experiments showed that in ovo feeding reduces...... 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...

  5. An Arabidopsis Ran-binding protein, AtRanBP1c, is a co-activator of Ran GTPase-activating protein and requires the C-terminus for its cytoplasmic localization

    Science.gov (United States)

    Kim, Soo-Hwan; Roux, Stanley J.

    2003-01-01

    Ran-binding proteins (RanBPs) are a group of proteins that bind to Ran (Ras-related nuclear small GTP-binding protein), and thus either control the GTP/GDP-bound states of Ran or help couple the Ran GTPase cycle to a cellular process. AtRanBP1c is a Ran-binding protein from Arabidopsis thaliana (L.) Heynh. that was recently shown to be critically involved in the regulation of auxin-induced mitotic progression [S.-H. Kim et al. (2001) Plant Cell 13:2619-2630]. Here we report that AtRanBP1c inhibits the EDTA-induced release of GTP from Ran and serves as a co-activator of Ran-GTPase-activating protein (RanGAP) in vitro. Transient expression of AtRanBP1c fused to a beta-glucuronidase (GUS) reporter reveals that the protein localizes primarily to the cytosol. Neither the N- nor C-terminus of AtRanBP1c, which flank the Ran-binding domain (RanBD), is necessary for the binding of PsRan1-GTP to the protein, but both are needed for the cytosolic localization of GUS-fused AtRanBP1c. These findings, together with a previous report that AtRanBP1c is critically involved in root growth and development, imply that the promotion of GTP hydrolysis by the Ran/RanGAP/AtRanBP1c complex in the cytoplasm, and the resulting concentration gradient of Ran-GDP to Ran-GTP across the nuclear membrane could be important in the regulation of auxin-induced mitotic progression in root tips of A. thaliana.

  6. Exploiting Natural Variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana . This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  7. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    J.A. Molenaar; J.J.B. Keurentjes

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of g

  8. The salty tale of Arabidopsis.

    Science.gov (United States)

    Sanders, D

    2000-06-29

    High concentrations of sodium chloride are toxic to most plant species. New insights into the mechanisms by which plants tolerate salt have emerged from the identification of genes in Arabidopsis thaliana that play a critical part in physiological resistance to salt.

  9. 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....

  10. 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....

  11. Re-analysis by fluorescence in situ hybridisation of spare embryos cultured until Day 5 after preimplantation genetic diagnosis for a 47, XYY infertile patient demonstrates a high incidence of diploid mosaic embryos: a case report.

    Science.gov (United States)

    Emiliani, S; Merino, E G; Van den Bergh, M; Abramowicz, M; Vassart, G; Englert, Y; Delneste, D

    2000-12-01

    Mosaicism in 4-8-cell human embryos analysed by fluorescence in situ hybridisation (FISH) has been widely reported, but few studies have addressed the incidence of mosaicism in more advanced embryonic stages. In the present study we analysed spare human embryos in a case of preimplantation genetic diagnosis (PGD) for increased risk of aneuploidy because of an infertile 47,XYY man. After replacement of two embryos typed as 1818XX at PGD, six spare embryos (not frozen because of their low quality) were re-analysed on Day 5 for PGD confirmation. Out of five embryos typed as 1818XY at PGD, four were diploid mosaic (DM) and one was normal in all cells. The sixth embryo, typed as 18XYY/1818181818X at PGD, was a DM. In spite of the bias of our small series of morphologically low-quality embryos, the surprisingly high proportion of mosaics (which confirms previous findings) questions the validity of PGD, but supports the strategy of transferring only the embryos where two blastomeres gave normal and concordant results at PGD. More data are required to understand the clinical significance of early diploid mosaicism (and its impact on implantation rate) and to determine whether some diploid mosaic embryos might be considered safe for transfer.

  12. 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.

  13. Interfacing Lab-on-a-Chip Embryo Technology with High-Definition Imaging Cytometry.

    Science.gov (United States)

    Zhu, Feng; Hall, Christopher J; Crosier, Philip S; Wlodkowic, Donald

    2015-08-01

    To spearhead deployment of zebrafish embryo biotests in large-scale drug discovery studies, automated platforms are needed to integrate embryo in-test positioning and immobilization (suitable for high-content imaging) with fluidic modules for continuous drug and medium delivery under microperfusion to developing embryos. In this work, we present an innovative design of a high-throughput three-dimensional (3D) microfluidic chip-based device for automated immobilization and culture and time-lapse imaging of developing zebrafish embryos under continuous microperfusion. The 3D Lab-on-a-Chip array was fabricated in poly(methyl methacrylate) (PMMA) transparent thermoplastic using infrared laser micromachining, while the off-chip interfaces were fabricated using additive manufacturing processes (fused deposition modelling and stereolithography). The system's design facilitated rapid loading and immobilization of a large number of embryos in predefined clusters of traps during continuous microperfusion of drugs/toxins. It was conceptually designed to seamlessly interface with both upright and inverted fluorescent imaging systems and also to directly interface with conventional microtiter plate readers that accept 96-well plates. Compared with the conventional Petri dish assays, the chip-based bioassay was much more convenient and efficient as only small amounts of drug solutions were required for the whole perfusion system running continuously over 72 h. Embryos were spatially separated in the traps that assisted tracing single embryos, preventing interembryo contamination and improving imaging accessibility.

  14. Minimally invasive transabdominal collection of preimplantation embryos from the common marmoset monkey (Callithrix jacchus).

    Science.gov (United States)

    Hanazawa, K; Mueller, T; Becker, T; Heistermann, M; Behr, R; Sasaki, E

    2012-09-01

    A novel, minimally invasive, transabdominal embryo collection method (transabdominal method) was developed as an alternative to a standard abdominal incision for embryo collection in the common marmoset. The abdominal incision method was used for 304 flushes using 36 female animals, whereas the transabdominal method was used for 488 flushes using 48 females; successful embryo collection rates were 48.0% and 48.4% (P > 0.05), respectively. These techniques were successfully duplicated at another institute (German Primate Center, DPZ). At that institution, successful embryo collection rates were 88.9% and 77.8% for the abdominal incision and transabdominal methods, respectively (P > 0.05), whereas the average numbers of preimplantation embryos obtained per flush were (mean ± SD) 1.91 ± 0.35 and 1.71 ± 0.14 (P > 0.05). The transabdominal method reduced animal stress, did not require incisional wound healing, and enabled successive embryo recoveries to be done much sooner. More embryos in early developmental stages (zygotes/morulae) were recovered using the transabdominal method (76.1%) than the abdominal incision method (52.6%, P marmoset developmental biology and embryology.

  15. The effect of alpha-amanitin on the Arabidopsis seed proteome highlights the distinct roles of stored and neosynthesized mRNAs during germination.

    Science.gov (United States)

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

    2004-04-01

    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 transcription, while subsequent seedling growth was blocked. In contrast, germination was abolished in the presence of the translational inhibitor cycloheximide. Taken together, the results highlight the role of stored proteins and mRNAs for germination in Arabidopsis and show that in this species the potential for germination is largely programmed during the seed maturation process. The alpha-amanitin-resistant germination exhibited characteristic features. First, this germination was strongly slowed down, indicating that de novo transcription normally allows the synthesis of factor(s) activating the germination rate. Second, the sensitivity of germination to gibberellic acid was reduced 15-fold, confirming the role of this phytohormone in germination. Third, de novo synthesis of enzymes involved in reserve mobilization and resumption of metabolic activity was repressed, thus accounting for the failure in seedling establishment. Fourth, germinating seeds can recapitulate at least part of the seed maturation program, being capable of using mRNAs stored during development. Thus, commitment to germination and plant growth requires transcription of genes allowing the imbibed seed to discriminate between mRNAs to be utilized in germination and those to be destroyed.

  16. Cyclin-dependent kinase-activating kinases CDKD;1 and CDKD;3 are essential for preserving mitotic activity in Arabidopsis thaliana.

    Science.gov (United States)

    Takatsuka, Hirotomo; Umeda-Hara, Chikage; Umeda, Masaaki

    2015-06-01

    For the full activation of cyclin-dependent kinases (CDKs), not only cyclin binding but also CDK phosphorylation is required. This activating phosphorylation is mediated by CDK-activating kinases (CAKs). Arabidopsis has four genes showing similarity to vertebrate-type CAKs, three CDKDs (CDKD;1-CDKD;3) and one CDKF (CDKF;1). We previously found that the cdkf;1 mutant is defective in post-embryonic development, even though the kinase activities of core CDKs remain unchanged relative to the wild type. This raised a question about the involvement of CDKDs in CDK activation in planta. Here we report that the cdkd;1 cdkd;3 double mutant showed gametophytic lethality. Most cdkd;1-1 cdkd;3-1 pollen grains were defective in pollen mitosis I and II, producing one-cell or two-cell pollen grains that lacked fertilization ability. We also found that the double knock-out of CDKD;1 and CDKD;3 caused arrest and/or delay in the progression of female gametogenesis at multiple steps. Our genetic analyses revealed that the functions of CDKF;1 and CDKD;1 or CDKD;3 do not overlap, either during gametophyte and embryo development or in post-embryonic development. Consistent with these analyses, CDKF;1 expression in the cdkd;1-1 cdkd;3-1 mutant could not rescue the gametophytic lethality. These results suggest that, in Arabidopsis, CDKD;1 and CDKD;3 function as CAKs controlling mitosis, whereas CDKF;1 plays a distinct role, mainly in post-embryonic development. We propose that CDKD;1 and CDKD;3 phosphorylate and activate all core CDKs, CDKA, CDKB1 and CDKB2, thereby governing cell cycle progression throughout plant development.

  17. 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.

  18. Acid peptidase activity released from in vitro produced porcine embryos: a candidate marker to predict developmental competence.

    Science.gov (United States)

    Telugu, Bhanu Prakash V L; Spate, Lee; Prather, Randall S; Green, Jonathan A

    2009-04-01

    The ability to efficiently create high quality embryos, competent to produce normal viable offspring in vitro, facilitates diverse technological advancements in animal agriculture and assisted reproduction. Current methods for evaluation of embryos are predominantly based on morphological characteristics which are prone to potential bias of the scorer. Metabolic and genetic markers have also been explored for quality assessment, but they are cost prohibitive or require longer periods of time for evaluation. We hypothesized that secreted enzymes could provide another means of embryo quality assessment. In this report, we provide evidence that medium conditioned by porcine embryos often has proteolytic activity that operates in acidic conditions (acid peptidase activity or APA). The APA could be inhibited by pepstatin A, suggesting that the activity is derived from one or more aspartic peptidases. We also provide evidence that single embryos, incubated for as few as 24 hr, released enough APA that it was possible to measure it accurately at day 5 of culture. We also observed that such activity on day 6 could be positively correlated with advanced developmental stage and embryo quality. In addition, those embryos that were graded identically by morphological evaluations often differed in the amount of APA--with some being significantly higher than the experimental threshold value. Therefore, the APA of embryos might serve as an additional marker for evaluation of embryos.

  19. Functional analysis of the cellulose synthase-like genes CSLD1, CSLD2 and CSLD4 in tip-growing arabidopsis cells

    DEFF Research Database (Denmark)

    Bernal Giraldo, Adriana Jimena; Yoo, Cheol-Min; Mutwil, Marek;

    2008-01-01

    A reverse genetic approach was used to investigate the functions of three members of the cellulose synthase superfamily in Arabidopsis (Arabidopsis thaliana), CELLULOSE SYNTHASE-LIKE D1 (CSLD1), CSLD2, and CSLD4. CSLD2 is required for normal root hair growth but has a different role from...

  20. 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.

  1. 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.

  2. Embryo-lethal phenotypes in early abp1 mutants are due to disruption of the neighboring BSM gene

    OpenAIRE

    Michalko, Jaroslav; Dravecká, Marta; Bollenbach, Tobias; Friml, Jiří

    2015-01-01

    The Auxin Binding Protein1 (ABP1) has been identified based on its ability to bind auxin with high affinity and studied for a long time as a prime candidate for the extracellular auxin receptor responsible for mediating in particular the fast non-transcriptional auxin responses. However, the contradiction between the embryo-lethal phenotypes of the originally described Arabidopsis T-DNA insertional knock-out alleles (abp1-1 and abp1-1s) and the wild type-like phenotypes of other recently desc...

  3. Assessment of the embryo quality in the procedure of in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Bjelica Artur

    2016-01-01

    Full Text Available Introduction. Since reproductive technologies are becoming increasingly popular among the couples with infertility problem, and having in mind that the success rate is still low, the clinicians tend to transfer more embryos in order to increase the probability of success. However, such a strategy increases the risk of multiple pregnancy, which brings about numerous risks to the health of both the mother and children. Therefore, an elective single-embryo transfer is set as imperative, which, on the other hand, would not be possible without selection and evaluation of the quality of embryos. Assessment of Embryo Quality. Embryos can be selected by various methods, from non-invasive to invasive methods. In non-invasive methods, the embryos are selected by their morphology or by the techniques based on the analysis of molecular components - analyses of the level of proteomes or metabolomes. A more detailed monitoring of the kinetics of the embryo development can be related to the introduction of time-lapse imaging and monitoring systems into laboratory practice. The invasive methods encompass the techniques such as preimplantation genetic diagnosis and preimplantation genetic screening. In preimplantation genetic diagnosis, the assisted reproduction technologies cycle is approached for the genetic reasons, whereas preimplantation genetic screening is used to enhance the success rate of the assisted reproduction cycles. Conclusion. In this paper we have shown that the application of elective single-embryo transfer requires the selection and assessment of the quality of embryos by the methods that have been developed in the last four decades, and still need further improvements.

  4. Supplement of autologous ooplasm into porcine somatic cell nuclear transfer embryos does not alter embryo development.

    Science.gov (United States)

    Lee, W-J; Lee, J-H; Jeon, R-H; Jang, S-J; Lee, S-C; Park, J-S; Lee, S-L; King, W-A; Rho, G-J

    2017-02-13

    Somatic cell nuclear transfer (SCNT) is considered as the technique in which a somatic cell is introduced into an enucleated oocyte to make a cloned animal. However, it is unavoidable to lose a small amount of the ooplasm during enucleation step during SCNT procedure. The present study was aimed to uncover whether the supplement of autologous ooplasm could ameliorate the oocyte competence so as to improve low efficiency of embryo development in porcine SCNT. Autologous ooplasm-transferred (AOT) embryos were generated by the supplementation with autologous ooplasm into SCNT embryos. They were comparatively evaluated with respect to embryo developmental potential, the number of apoptotic body formation and gene expression including embryonic lineage differentiation, apoptosis, epigenetics and mitochondrial activity in comparison with parthenogenetic, in vitro-fertilized (IVF) and SCNT embryos. Although AOT embryos showed perfect fusion of autologous donor ooplasm with recipient SCNT embryos, the supplement of autologous ooplasm could not ameliorate embryo developmental potential in regard to the rate of blastocyst formation, total cell number and the number of apoptotic body. Furthermore, overall gene expression of AOT embryos was presented with no significant alterations in comparison with that of SCNT embryos. Taken together, the results of AOT demonstrated inability to make relevant values improved from the level of SCNT embryos to their IVF counterparts.

  5. 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...

  6. Reference: 358 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available amyl-cysteine synthetase. These gsh1 mutants confer a recessive embryo-lethal phenotype, in contrast to the ...dual amounts of GSH in rml1 embryos. In contrast, gsh1 T-DNA insertion mutant embryos could not be labeled w

  7. 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...

  8. 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.

  9. Reference: 710 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available n factor family in Arabidopsis (Arabidopsis thaliana). Treatment with abscisic acid (ABA) induced AtMYB44 tr...anscript accumulation within 30 min. The gene was also activated under various abiotic stre...sses, such as dehydration, low temperature, and salinity. In transgenic Arabidopsis carrying an At...MYB44 promoter-driven beta-glucuronidase (GUS) construct, strong GUS activity was observed in the vasculature... and leaf epidermal guard cells. Transgenic Arabidopsis overexpressing AtMYB44 is more

  10. Parameters influencing derivation of embryonic stem cells from murine embryos.

    Science.gov (United States)

    Batlle-Morera, Laura; Smith, Austin; Nichols, Jennifer

    2008-12-01

    The derivation of ES cells is poorly understood and varies in efficiency between different strains of mice. We have investigated potential differences between embryos of permissive and recalcitrant strains during diapause and ES cell derivation. We found that in diapause embryos of the recalcitrant C57BL/6 and CBA strains, the epiblast failed to expand during the primary explant phase of ES cell derivation, whereas in the permissive 129 strain, it expanded dramatically. Epiblasts from the recalcitrant strains could be expanded by reducing Erk activation. Isolation of 129 epiblasts facilitated very efficient derivation of ES cell lines in serum- and feeder-free conditions, but reduction of Erk activity was required for derivation of ES cells from isolated C57BL/6 or CBA epiblasts. The results suggest that the discrepancy in ES cell derivation efficiency is not attributable merely to variable prodifferentiative effects of the extra-embryonic lineages but also to an intrinsic variability within the epiblast to maintain pluripotency.

  11. 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.

  12. Alterations in seed development gene expression affect size and oil content of Arabidopsis seeds.

    Science.gov (United States)

    Fatihi, Abdelhak; Zbierzak, Anna Maria; Dörmann, Peter

    2013-10-01

    Seed endosperm development in Arabidopsis (Arabidopsis thaliana) is under control of the polycomb group complex, which includes Fertilization Independent Endosperm (FIE). The polycomb group complex regulates downstream factors, e.g. Pheres1 (PHE1), by genomic imprinting. In heterozygous fie mutants, an endosperm develops in ovules carrying a maternal fie allele without fertilization, finally leading to abortion. Another endosperm development pathway depends on MINISEED3 (a WRKY10 transcription factor) and HAIKU2 (a leucine-rich repeat kinase). While the role of seed development genes in the embryo and endosperm establishment has been studied in detail, their impact on metabolism and oil accumulation remained unclear. Analysis of oil, protein, and sucrose accumulation in mutants and overexpression plants of the four seed development genes revealed that (1) seeds carrying a maternal fie allele accumulate low oil with an altered composition of triacylglycerol molecular species; (2) homozygous mutant seeds of phe1, mini3, and iku2, which are smaller, accumulate less oil and slightly less protein, and starch, which accumulates early during seed development, remains elevated in mutant seeds; (3) embryo-specific overexpression of FIE, PHE1, and MINI3 has no influence on seed size and weight, nor on oil, protein, or sucrose content; and (4) overexpression of IKU2 results in seeds with increased size and weight, and oil content of overexpressed IKU2 seeds is increased by 35%. Thus, IKU2 overexpression represents a novel strategy for the genetic manipulation of the oil content in seeds.

  13. User guide for mapping-by-sequencing in Arabidopsis.

    Science.gov (United States)

    James, Geo Velikkakam; Patel, Vipul; Nordström, Karl J V; Klasen, Jonas R; Salomé, Patrice A; Weigel, Detlef; Schneeberger, Korbinian

    2013-06-17

    Mapping-by-sequencing combines genetic mapping with whole-genome sequencing in order to accelerate mutant identification. However, application of mapping-by-sequencing requires decisions on various practical settings on the experimental design that are not intuitively answered. Following an experimentally determined recombination landscape of Arabidopsis and next generation sequencing-specific biases, we simulated more than 400,000 mapping-by-sequencing experiments. This allowed us to evaluate a broad range of different types of experiments and to develop general rules for mapping-by-sequencing in Arabidopsis. Most importantly, this informs about the properties of different crossing scenarios, the number of recombinants and sequencing depth needed for successful mapping experiments.

  14. 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.

  15. Microfluidics for mammalian embryo culture and selection: where do we stand now?

    Science.gov (United States)

    Le Gac, Séverine; Nordhoff, Verena

    2016-09-27

    The optimization of in-vitro culture conditions and the selection of the embryo(s) with the highest developmental competence are essential components in an ART program. Culture conditions are manifold and they underlie not always evidence-based research but also trends entering the IVF laboratory. At the moment, the idea of using sequential media according to the embryo requirements has been given up in favor of the use of single step media in an uninterrupted manner due to practical issues such as time-lapse incubators. The selection of the best embryo is performed using morphological and, recently, also morphokinetic criteria. In this review, we aim to demonstrate how the ART field may benefit from the use of microfluidic technology, with a particular focus on specific steps, namely the embryo in-vitro culture, embryo scoring and selection, and embryo cryopreservation. We first provide an overview of microfluidic and microfabricated devices, which have been developed for embryo culture, characterization of pre-implantation embryos (or in some instances a combination of both steps) and embryo cryopreservation. Building upon these existing platforms and the various capabilities offered by microfluidics, we discuss how this technology could provide integrated and automated systems, not only for real-time and multi-parametric monitoring of embryo development, but also for performing the entire ART procedure. Although microfluidic technology has been around for a couple of decades already, it has still not made its way into the clinics and IVF laboratories, which we discuss in terms of: (i) a lack of user-friendliness and automation of the microfluidic platforms, (ii) a lack of robust and convincing validation using human embryos and (iii) some psychological threshold for embryologists and practitioners to test and use microfluidic technology. In spite of these limitations, we envision that microfluidics is likely to have a significant impact in the field of ART, for

  16. Factors influencing the outcome of embryo freezing and thawing program

    Institute of Scientific and Technical Information of China (English)

    叶英辉; 金帆; 徐晨明; 邢兰凤

    2002-01-01

    Objective: To investigate the factors that might influence the succ ess of an embryo freezing and thawing program. Method: The relationship betwee n the pregnancy rate in 73 cycles of embryo freezing and thawing program and the following factors was analyzed: maternal age, E2 level at the time of HCG trigg er, embryo storage time, number of thawed embryos transferred, presence of spons oring embryos and intact embryos. And the survival rate of thawed embryos with d ifferent morphology, cell stage and storage time was evaluated. Result: Tra nsfer with three or more than three thawed embryos resulted in pregnancy rates o f 38.5% and 35.7%, respectively, compared with 5.3% for transfer of fewer th an t hree embryos. The presence of sponsoring embryos and intact embryos significantl y increases pregnancy rate in embryo freezing and thawing program. No other fact or examined had any effect on pregnancy outcome. The survival rate of good morph ology embryos was higher than poor ones, but was not influenced by cell stage an d storage time. Conclusion: Embryo morphology before freezing, number of thaw ed embryos transferred and the presence of intact embryos are important to the o utcome of embryo freezing and thawing program.

  17. Seed-Specific Overexpression of the Pyruvate Transporter BASS2 Increases Oil Content in Arabidopsis Seeds

    Science.gov (United States)

    Lee, Eun-Jung; Oh, Minwoo; Hwang, Jae-Ung; Li-Beisson, Yonghua; Nishida, Ikuo; Lee, Youngsook

    2017-01-01

    Seed oil is important not only for human and animal nutrition, but also for various industrial applications. Numerous genetic engineering strategies have been attempted to increase the oil content per seed, but few of these strategies have involved manipulating the transporters. Pyruvate is a major source of carbon for de novo fatty acid biosynthesis in plastids, and the embryo's demand for pyruvate is reported to increase during active oil accumulation. In this study, we tested our hypothesis that oil biosynthesis could be boosted by increasing pyruvate flux into plastids. We expressed the known plastid-localized pyruvate transporter BILE ACID:SODIUM SYMPORTER FAMILY PROTEIN 2 (BASS2) under the control of a seed-specific soybean (Glycine max) glycinin-1 promoter in Arabidopsis thaliana. The resultant transgenic Arabidopsis plants (OEs), which expressed high levels of BASS2, produced seeds that were larger and heavier and contained 10–37% more oil than those of the wild type (WT), but were comparable to the WT seeds in terms of protein and carbohydrate contents. The total seed number did not differ significantly between the WT and OEs. Therefore, oil yield per plant was increased by 24–43% in the OE lines compared to WT. Taken together, our results demonstrate that seed-specific overexpression of the pyruvate transporter BASS2 promotes oil production in Arabidopsis seeds. Thus, manipulating the level of specific transporters is a feasible approach for increasing the seed oil content.

  18. The Arabidopsis ISR1 locus controlling rhizobacteria-mediated induced systemic resistance is involved in ethylene signaling

    OpenAIRE

    Ton, J.; Davison, S; Wees, A.C.M. van; Loon, L. C. van; Pieterse, C.M.J.

    2001-01-01

    In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers an induced systemic resistance (ISR) response that is effective against different types of pathogens. The ISR signaling pathway functions independent of salicylic acid, but requires responsiveness to jasmonate (JA) and ethylene. Using the genetic variability of ISR inducibility between Arabidopsis accessions, we recently identified a locus (ISR1) on chromosome III that is involved in ISR signaling. Accessions R...

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

    Science.gov (United States)

    Cui, Xiaona; Guo, Zhiai; Song, Lizhen; Wang, Yanli; Cheng, Youfa

    2016-03-01

    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.

  20. 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...

  1. Biofluid Flow Simulations of Embryo Transfer

    Science.gov (United States)

    Shi, W. P.; Ding, D. L.

    2011-09-01

    The investigation of the fluid flow for embryo transfer (ET) procedure may find the way to increase the success rate of the assisted reproductive technologies. In this paper, the transferred liquid flow in the uterine cavity during ET procedure is simulated by a two dimensional multiphase flow model, and the discrete phase model is adopted to trace the embryo motion. Through the investigation on the transferred liquid outline and the track of each embryo in ET cases with different parameters, we summarize the effect of transferred liquid viscosity and distance between catheter tip and uterine fundus. According to the numerical results, we recommend the optimizing standard to perform the ET procedure.

  2. Moral qualms, future persons, and embryo research.

    Science.gov (United States)

    Shaw, David Martin

    2008-05-01

    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 have towards future persons.

  3. Association between Number of Formed Embryos, Embryo Morphology and Clinical Pregnancy Rate after Intracytoplasmic Sperm Injection.

    Science.gov (United States)

    Luz, Caroline Mantovani da; Giorgi, Vanessa Silvestre Innocenti; Coelho Neto, Marcela Alencar; Martins, Wellington de Paula; Ferriani, Rui Alberto; Navarro, Paula Andrea

    2016-09-01

    Introduction Infertility has a high prevalence in the general population, affecting ∼ 5 to 15% of couples in reproductive age. The assisted reproduction techniques (ART) include in vitro manipulation of gametes and embryos and are an important treatment indicated to these couples. It is well accepted that the implantation rate is positively influenced by the morphology of transferred embryos. However, we question if, apart from the assessment of embryo morphology, the number of produced embryos per cycle is also related to pregnancy rates in the first fresh transfer cycle. Purpose To evaluate the clinical pregnancy rate according to the number of formed embryos and the transfer of top quality embryos (TQEs). Methods In a retrospective cohort study, between January 2011 and December 2012, we evaluated women who underwent intracytoplasmic sperm injection (ICSI), aged < 40 years, and with at least 1 formed embryo fresh transferred in cleavage stage. These women were stratified into 3 groups according to the number of formed embryos (1 embryo, 2-3 and ≥ 4 embryos). Each group was divided into 2 subgroups according to the presence or not of at least 1 transferred TQE (1 with TQE; 1 without TQE; 2-3 with TQE, 2-3 without TQE; ≥ 4 with TQE; ≥ 4 without TQE). The clinical pregnancy rates were compared in each subgroup based on the presence or absence of at least one transferred TQE. Results During the study period, 636 women had at least one embryo to be transferred in the first fresh cycle (17.8% had 1 formed embryo [32.7% with TQE versus 67.3% without TQE], 42.1% of women had 2-3 formed embryos [55.6% with TQE versus 44.4% without TQE], and 40.1% of patients had ≥ 4 formed embryos [73.7% with TQE versus 26.3% without TQE]). The clinical pregnancy rate was significantly higher in the subgroup with ≥ 4 formed embryos with at least 1 transfered TQE (45.2%) compared with the subgroup without TQE (28.4%). Conclusions Having at

  4. Arabidopsis CDS blastp result: AK240652 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240652 J023098G11 At5g63090.2 68418.m07919 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 1e-13 ...

  5. Arabidopsis CDS blastp result: AK241761 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241761 J065205C18 At5g63090.1 68418.m07918 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 5e-32 ...

  6. Arabidopsis CDS blastp result: AK240652 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240652 J023098G11 At5g63090.1 68418.m07918 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 1e-13 ...

  7. Arabidopsis CDS blastp result: AK240652 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240652 J023098G11 At5g63090.4 68418.m07921 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 1e-13 ...

  8. Arabidopsis CDS blastp result: AK241761 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241761 J065205C18 At5g63090.3 68418.m07920 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 5e-32 ...

  9. Arabidopsis CDS blastp result: AK241761 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241761 J065205C18 At5g63090.2 68418.m07919 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 5e-32 ...

  10. Arabidopsis CDS blastp result: AK241761 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241761 J065205C18 At5g63090.4 68418.m07921 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 5e-32 ...

  11. Arabidopsis CDS blastp result: AK240652 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240652 J023098G11 At5g63090.3 68418.m07920 LOB domain protein / lateral organ boundaries... protein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 1e-13 ...

  12. Arabidopsis CDS blastp result: AK105527 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105527 001-127-G05 At5g63090.4 LOB domain protein / lateral organ boundaries prot...ein (LOB) identical to LOBa [Arabidopsis thaliana] GI:17484100, SP|Q9FML4 LATERAL ORGAN BOUNDARIES protein {Arabidopsis thaliana} 3e-52 ...

  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…

  14. Arabidopsis CDS blastp result: AK240730 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240730 J043030K09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 2e-11 ...

  15. Arabidopsis CDS blastp result: AK288052 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288052 J075151I09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 6e-14 ...

  16. Arabidopsis CDS blastp result: AK240911 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240911 J065037E05 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 4e-22 ...

  17. Arabidopsis CDS blastp result: AK241119 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241119 J065094C22 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 2e-13 ...

  18. Arabidopsis CDS blastp result: AK243149 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243149 J100032I21 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 7e-12 ...

  19. Arabidopsis CDS blastp result: AK241581 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241581 J065181K09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 4e-15 ...

  20. Arabidopsis CDS blastp result: AK287479 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287479 J043023O14 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 1e-17 ...

  1. Reference: 631 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ggest that atRZ-1a has a negative impact on seed germination and seedling growth of Arabidopsis under salt o...binding protein, atRZ-1a, has a negative impact on seed germination and seedling growth of Arabidopsis thali

  2. Ultrastructural changes in goat interspecies and intraspecies reconstructed early embryos

    DEFF Research Database (Denmark)

    Tao, Yong; Gheng, Lizi; Zhang, Meiling

    2008-01-01

    development. The zona pellucida (ZP) in all three types of embryos became thinner and ZP pores in both GC and GG embryos showed an increased rate of development, especially for GC embryos, while in vivo-produced embryos had smooth ZP. The Golgi apparatus (Gi) and rough endoplasmic reticulum (RER) of the two...

  3. Factors influencing the outcome of embryo freezing and Ihawing program

    Institute of Scientific and Technical Information of China (English)

    叶英辉; 金帆; 徐晨明; 邢兰凤

    2002-01-01

    Objective: To investigate the factors that might influence the sucess of an ernbryo freezing and thawing program.Method: The relationship between the pregnancy rate in 73 cycles of embryo freezing and thewing program and the following factors was analyzed;matermal age,E2 level at the time of HCG trigger,embryo storage time,number of thawed embryos transferred,presence of sponsoring embryos and intact embryos.And the suvival rate of thawed embryos with different morphology,cell stage and storage time was evaluated.Result:Transfer with three of more than three thawed embryos resulted in pragnancy rates of 38.5% and 35.7%,respectively.compared with 5.3% for transfer of fewer than three embryos.The presence of sponsoring embryos and intact embryos significantly incresses pregnancy rate in embryo freezing and thawing program .No other factor examined had any effect on pregnancy outcome.The survival rate of good morphology embryos was higher than poor ones,but was not influenced by cell stage and storage time.Conclusion:Embryo morphology before freezing , number of thawed embryos transferred and the presence of intact embryos are important to the outcome of embryo freezing and thawing program.

  4. Developmental competence of porcine chimeric embryos produced by aggregation

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  5. The MADS Box Genes ABS, SHP1, and SHP2 Are Essential for the Coordination of Cell Divisions in Ovule and Seed Coat Development and for Endosperm Formation in Arabidopsis thaliana.

    Science.gov (United States)

    Ehlers, Katrin; Bhide, Amey S; Tekleyohans, Dawit G; Wittkop, Benjamin; Snowdon, Rod J; Becker, Annette

    2016-01-01

    Seed formation is a pivotal process in plant reproduction and dispersal. It begins with megagametophyte development in the ovule, followed by fertilization and subsequently coordinated development of embryo, endosperm, and maternal seed coat. Two closely related MADS-box genes, SHATTERPROOF 1 and 2 (SHP1 and SHP2) are involved in specifying ovule integument identity in Arabidopsis thaliana. The MADS box gene ARABIDOPSIS BSISTER (ABS or TT16) is required, together with SEEDSTICK (STK) for the formation of endothelium, part of the seed coat and innermost tissue layer formed by the maternal plant. Little is known about the genetic interaction of SHP1 and SHP2 with ABS and the coordination of endosperm and seed coat development. In this work, mutant and expression analysis shed light on this aspect of concerted development. Triple tt16 shp1 shp2 mutants produce malformed seedlings, seed coat formation defects, fewer seeds, and mucilage reduction. While shp1 shp2 mutants fail to coordinate the timely development of ovules, tt16 mutants show less peripheral endosperm after fertilization. Failure in coordinated division of the innermost integument layer in early ovule stages leads to inner seed coat defects in tt16 and tt16 shp1 shp2 triple mutant seeds. An antagonistic action of ABS and SHP1/SHP2 is observed in inner seed coat layer formation. Expression analysis also indicates that ABS represses SHP1, SHP2, and FRUITFUL expression. Our work shows that the evolutionary conserved Bsister genes are required not only for endothelium but also for endosperm development and genetically interact with SHP1 and SHP2 in a partially antagonistic manner.

  6. Cytochemical localization of reserves during seed development in Arabidopsis thaliana under spaceflight conditions

    Science.gov (United States)

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

    1996-01-01

    Successful development of seeds under spaceflight conditions has been an elusive goal of numerous long-duration experiments with plants on orbital spacecraft. Because carbohydrate metabolism undergoes changes when plants are grown in microgravity, developing seed storage reserves might be detrimentally affected during spaceflight. Seed development in Arabidopsis thaliana plants that flowered during 11 d in space on shuttle mission STS-68 has been investigated in this study. Plants were grown to the rosette stage (13 d) on a nutrient agar medium on the ground and loaded into the Plant Growth Unit flight hardware 18 h prior to lift-off. Plants were retrieved 3 h after landing and siliques were immediately removed from plants. Young seeds were fixed and processed for microscopic observation. Seeds in both the ground control and flight plants are similar in their morphology and size. The oldest seeds from these plants contain completely developed embryos and seed coats. These embryos developed radicle, hypocotyl, meristematic apical tissue, and differentiated cotyledons. Protoderm, procambium, and primary ground tissue had differentiated. Reserves such as starch and protein were deposited in the embryos during tissue differentiation. The aleurone layer contains a large quantity of storage protein and starch grains. A seed coat developed from integuments of the ovule with gradual change in cell composition and cell material deposition. Carbohydrates were deposited in outer integument cells especially in the outside cell walls. Starch grains decreased in number per cell in the integument during seed coat development. All these characteristics during seed development represent normal features in the ground control plants and show that the spaceflight environment does not prevent normal development of seeds in Arabidopsis.

  7. Dosimetry of radioiodine for embryo and fetus

    Energy Technology Data Exchange (ETDEWEB)

    Berkovski, V.; Eckerman, K.F.; Phipps, A.W.; Nosske, D

    2003-07-01

    This paper discusses the biokinetic and dosimetric models adopted in ICRP Publication 88 for the evaluation of fetal doses resulting from maternal intakes of radioiodine. The biokinetic model is used to simulate the behaviour of iodine in both the mother and the fetus. Such simulations provide the basis for the estimation of the dose to the embryo and determine the distribution of maternal iodine at the beginning of the fetal period. The model considers iodine to accumulate in the fetal thyroid from the 11th week. The dose to the fetus delivered following birth is evaluated with the biokinetic and dosimetric models described in ICRP Publication 67. Although a substantial fraction of the emitted energy of electrons and photons is less than 10 keV, conventionally assumed to be non-penetrating radiation, these emissions can escape the small fetal thyroid. Absorbed fractions for both self-dose and crossfire were evaluated for the requirements of radioiodine dosimetry in ICRP Publication 88. (author)

  8. MiRNA-mediated regulation of cell signaling and homeostasis in the early mouse embryo.

    Science.gov (United States)

    Pernaute, Barbara; Spruce, Thomas; Rodriguez, Tristan A; Manzanares, Miguel

    2011-02-15

    At the time of implantation the mouse embryo is composed of three tissues the epiblast, trophectoderm and primitive endoderm. As development progresses the epiblast goes on to form the foetus whilst the trophectoderm and primitive endoderm give rise to extra-embryonic structures with important roles in embryo patterning and nutrition. Dramatic changes in gene expression occur during early embryo development and these require regulation at different levels. miRNAs are small non coding RNAs that have emerged over the last decade as important post-transcriptional repressors of gene expression. The roles played by miRNAs during early mammalian development are only starting to be elucidated. In order to gain insight into the function of miRNAs in the different lineages of the early mouse embryo we have analysed in depth the phenotype of embryos and extra-embryonic stem cells mutant for the miRNA maturation protein Dicer. This study revealed that miRNAs are involved in regulating cell signaling and homeostasis in the early embryo. Specifically, we identified a role for miRNAs in regulating the Erk signaling pathway in the extra-embryonic endoderm, cell cycle progression in extra-embryonic tissues and apoptosis in the epiblast.

  9. Toward embedded laboratory automation for smart Lab-on-a-Chip embryo arrays.

    Science.gov (United States)

    Wang, Kevin I-Kai; Salcic, Zoran; Yeh, Johnny; Akagi, Jin; Zhu, Feng; Hall, Chris J; Crosier, Kathryn E; Crosier, Philip S; Wlodkowic, Donald

    2013-10-15

    Lab-on-a-Chip (LOC) biomicrofluidic technologies are rapidly emerging bioanalytical tools that can miniaturize and revolutionize in situ research on embryos of small vertebrate model organisms such as zebrafish (Danio rerio) and clawed African frog (Xenopus laevis). Despite considerable progress being made in fabrication techniques of chip-based devices, they usually still require excessive and manual actuation and data acquisition that significantly reduce throughput and introduce operator-related analytical bias. This work describes the development of a proof-of-concept embedded platform that integrates an innovative LOC zebrafish embryo array technology with an electronic interface to provide higher levels of laboratory automation for in situ biotests. The integrated platform was designed to perform automatic immobilization, culture and treatment of developing zebrafish embryos during fish embryo toxicity (FET) biotests. The system was equipped with a stepper motor driven stage, solenoid-actuated pinch valves, miniaturized peristaltic pumps as well as Peltier heating module. Furthermore, a Field Programmable Gate Array (FPGA) was used to implement an embedded hardware/software solution and interface to enable real-time control over embryo loading and immobilization; accurate microfluidic flow control; temperature stabilization and also automatic time-resolved image acquisition of developing zebrafish embryos. This work presents evidence that integration of embedded electronic interfaces with microfluidic chip-based technologies can bring the Lab-on-a-Chip a step closer to fully automated analytical systems.

  10. 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.

  11. Ethical euthanasia and short-term anesthesia of the chick embryo.

    Science.gov (United States)

    Aleksandrowicz, Ewa; Herr, Ingrid

    2015-01-01

    Fertilized chicken eggs are suggested as an alternative to mammalian models. The chorioallantoic membrane (CAM) of the chick embryo is widely used for examination of angiogenesis, xenotransplants and for virus production. Unfortunately, it is mostly not taken into account, that the chick embryo's ability to experience pain starts to develop at day 7 of breeding. In our view, this model is only in accordance with the 3 R principles, if an appropriate anesthesia of the chick embryo in potentially painful procedures is provided. Although many experimental approaches are performed on the none-innervated CAM, the euthanasia of the embryo strongly requires a more human technique than the usually used freezing at -20°C, decapitation or in ovo fixation with paraformaldehyde without prior anesthesia. However, protocols regarding feasible and ethical methods for anesthesia and euthanasia of avian embryos are currently not available. Therefore, we established an easy and reliable method for the euthanasia and short-term anesthesia of the chick embryo.

  12. Early gene expression along the animal-vegetal axis in sea urchin embryoids and grafted embryos.

    Science.gov (United States)

    Ghiglione, C; Emily-Fenouil, F; Chang, P; Gache, C

    1996-10-01

    The HE gene is the earliest strictly zygotic gene activated during sea urchin embryogenesis. It is transiently expressed in a radially symmetrical domain covering the animal-most two-thirds of the blastula. The border of this domain, which is orthogonal to the primordial animal-vegetal axis, is shifted towards the animal pole in Li+-treated embryos. Exogenous micromeres implanted at the animal pole of whole embryos, animal or vegetal halves do not modify the extent and localization of the HE expression domain. In grafted embryos or animal halves, the Li+ effect is not affected by the presence of ectopic micromeres at the animal pole. A Li+-induced shift of the border, similar to that seen in whole embryos, occurs in embryoids developing from animal halves isolated from 8-cell stage embryos or dissected from unfertilised eggs. Therefore, the spatial restriction of the HE gene is not controlled by the inductive cascade emanating from the micromeres and the patterning along the AV-axis revealed by Li+ does not require interactions between cells from the animal and vegetal halves. This suggests that maternal primary patterning in the sea urchin embryo is not limited to a small vegetal center but extends along the entire AV axis.

  13. The Role of Gravity on the Reproduction of Arabidopsis Plants

    Science.gov (United States)

    Hoshizaki, T.

    1985-01-01

    The presence of gravity as a necessary environmental factor for higher plants to complete their life cycle was examined. Arabidopsis thalliana (L.) Heynh. Columbia strain plants were grown continuously for three generations in a simulated micro-g environment as induced by horizontal clinostats. Growth, development and reproduction were followed. The Arabidopsis plants were selected for three generations on clinostats because: (1) a short life cycle of around 35 days; (2) the cells of third generation plants would in theory be free of gravity imprint; and (3) a third generation plant would therefore more than likely grow and respond like a plant growing in a micro-g environment. It is found that gravity is not a required environmental factor for higher plants to complete their life cycle, at least as tested by a horizontal clinostat. Clinostatting does not prevent the completion of the plant life cycle. However, clinostatting does appear to slow down the reproductive process of Arabidopsis plants. Whether higher plants can continue to reproduce for many generations in a true micro-g environment of space can only be determined by long duration experiments in space.

  14. Cadmium interferes with maintenance of auxin homeostasis in Arabidopsis seedlings.

    Science.gov (United States)

    Hu, Yan Feng; Zhou, Guoying; Na, Xiao Fan; Yang, Lijing; Nan, Wen Bin; Liu, Xu; Zhang, Yong Qiang; Li, Jiao Long; Bi, Yu Rong

    2013-07-15

    Auxin and its homeostasis play key roles in many aspects of plant growth and development. Cadmium (Cd) is a phytotoxic heavy metal and its inhibitory effects on plant growth and development have been extensively studied. However, the underlying molecular mechanism of the effects of Cd stress on auxin homeostasis is still unclear. In the present study, we found that the root elongation, shoot weight, hypocotyl length and chlorophyll content in wild-type (WT) Arabidopsis seedlings were significantly reduced after exposure to Cd stress. However, the lateral root (LR) formation was markedly promoted by Cd stress. The level and distribution of auxin were both greatly altered in primary root tips and cotyledons of Cd-treated plants. The results also showed that after Cd treatment, the IAA content was significantly decreased, which was accompanied by increases in the activity of the IAA oxidase and alteration in the expression of several putative auxin biosynthetic and catabolic genes. Application of the auxin transport inhibitor, 1-naphthylphthalamic acid (NPA) and 1-naphthoxyacetic acid (1-NOA), reversed the effects of Cd on LR formation. Additionally, there was less promotion of LR formation by Cd treatment in aux1-7 and pin2 mutants than that in the WT. Meanwhile, Cd stress also altered the expression of PINs and AUX1 in Arabidopsis roots, implying that the auxin transport pathway is required for Cd-modulated LR development. Taken together, these findings suggest that Cd stress disturbs auxin homeostasis through affecting auxin level, distribution, metabolism, and transport in Arabidopsis seedling.

  15. The Functions of RNA-Dependent RNA Polymerases in Arabidopsis

    Science.gov (United States)

    Willmann, Matthew R.; Endres, Matthew W.; Cook, Rebecca T.; Gregory, Brian D.

    2011-01-01

    One recently identified mechanism that regulates mRNA abundance is RNA silencing, and pioneering work in Arabidopsis thaliana and other genetic model organisms helped define this process. RNA silencing pathways are triggered by either self-complementary fold-back structures or the production of double-stranded RNA (dsRNA) that gives rise to small RNAs (smRNAs) known as microRNAs (miRNAs) or small-interfering RNAs (siRNAs). These smRNAs direct sequence-specific regulation of various gene transcripts, repetitive sequences, viruses, and mobile elements via RNA cleavage, translational inhibition, or transcriptional silencing through DNA methylation and heterochromatin formation. Early genetic screens in Arabidopsis were instrumental in uncovering numerous proteins required for these important regulatory pathways. Among the factors identified by these studies were RNA-dependent RNA polymerases (RDRs), which are proteins that synthesize siRNA-producing dsRNA molecules using a single-stranded RNA (ssRNA) molecule as a template. Recently, a growing body of evidence has implicated RDR-dependent RNA silencing in many different aspects of plant biology ranging from reproductive development to pathogen resistance. Here, we focus on the specific functions of the six Arabidopsis RDRs in RNA silencing, their ssRNA substrates and resulting RDR-dependent smRNAs, and the numerous biological functions of these proteins in plant development and stress responses. PMID:22303271

  16. 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.

  17. Effects of turning duration during incubation on embryo growth, utilization of albumen, and stress regulation.

    Science.gov (United States)

    Tona, K; Onagbesan, O; Bruggeman, V; Mertens, K; Decuypere, E

    2005-02-01

    Eggs from Cobb broiler breeders were incubated for 18 d. Eggs were not turned (T0) or were turned until 9 (T9), 12 (T12), 15 (T15), or 18 (T18) d. First, the effects of turning on embryo and albumen weights were studied. Samples of eggs were opened at d 9, 12, 15, and 18 for embryo and albumen weighing. The results show that embryos from unturned eggs had lower weights and higher remaining albumen weights than those from turned eggs. At d 18, albumen utilization was completed in the T12, T15, and T18 groups only. Also, further turning until d 15 and 18 increased embryo weights. The responsiveness of the embryo after adrenocorticotropic hormone (ACTH) injection was studied to test stress control in embryos. Blood samples were collected from embryos at 60 and 150 min after injection at d 12, 15, and 18 and were analyzed for corticosterone concentrations. The results showed that basal corticosterone levels increased with embryo age. At 60 min after ACTH injection, corticosterone levels were lower at d 12 than at d 15 and 18. At 150 min after ACTH injection, corticosterone levels followed different trends according to incubation stage and turning duration. The highest basal corticosterone levels were obtained with the T15 group at d 15 and 18. Also at d 18, corticosterone levels in the T15 group were the highest at 150 min after ACTH injection. We concluded that egg turning was required during incubation until d 12, at least, and should not be stopped until after d 15.

  18. 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

  19. Splitting and biopsy for bovine embryo sexing under field conditions.

    Science.gov (United States)

    Lopes, R F; Forell, F; Oliveira, A T; Rodrigues, J L

    2001-12-01

    Improvements on embryo micromanipulation techniques led to the use of embryo bisection technology in commercial embryo transfer programs, and made possible the direct genetic analysis of preimplantation bovine embryos by biopsy. For example, aspiration and microsection, allow bovine embryos sexing by detection of male-specific Y-chromosome in a sample of embryonic cells. We report on the application of the methodologies of splitting and biopsy of bovine embryos in field conditions, and on the results of embryo sex determination by the polymerase chain reaction (PCR). Pregnancy rates achieved with fresh bisected or biopsied embryos (50 to 60%) were similar to the fresh intact embryos (55 to 61%). The PCR protocol used for embryo sexing showed 92% to 94% of efficiency and 90 to 100% of accuracy. These results demonstrate these procedures are suitable for use in field conditions.

  20. 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 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 multiple pregnancies, thereby increasing the safety for mother and child. Finally the article describes the accumulating literature on perinatal and long-term child outcome after transfer of frozen/thawed embryos, including a discussion on the concerns regarding cryo techniques and their possible roles...

  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. Steroidal alkaloid toxicity to fish embryos.

    Science.gov (United States)

    Crawford, L; Kocan, R M

    1993-02-01

    Embryos of two species of fish were evaluated for their suitability as model systems for steroidal alkaloid toxicity, the Japanese rice fish, medaka (Oryzius latipes) and the rainbow trout (Oncorhynchus mykiss). Additionally, the equine neurotoxic sesquiterpene lactone repin, was also tested. A PROBIT program was used to evaluate the EC1, EC50 and EC99 as well as the associated confidence limits. The steroidal alkaloids tested were the Solanum potato glycoalkaloids alpha-chaconine, alpha-solanine, the aglyclones solanidine and solasodine and the Veratrum alkaloid, jervine. Embryo mortality, likely due to structural or functional abnormalities in the early development stages of the embryo, were the only response observed in both species. The rainbow trout exhibited a toxic response to chaconine, solasidine, repin and solanine but the medaka embryos were only affected by the compounds, chaconine and solanine. Rainbow trout may indeed serve as a good lower vertebrate model for studying the toxicity of steroidal alkaloids.

  3. The fate of the mosaic embryo : chromosomal constitution and development of Day 4, 5 and 8 human embryos

    NARCIS (Netherlands)

    Santos, Margarida Avo; Teklenburg, Gijs; Macklon, Nick S.; Van Opstal, Diane; Schuring-Blom, G. Heleen; Krijtenburg, Pieter-Jaap; de Vreeden-Elbertse, Johanna; Fauser, Bart C.; Baart, Esther B.

    2010-01-01

    Post-zygotic chromosome segregation errors are very common in human embryos after in vitro fertilization, resulting in mosaic embryos. However, the significance of mosaicism for the developmental potential of early embryos is unknown. We assessed chromosomal constitution and development of embryos f

  4. 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.

  5. Culture systems: embryo culture and monozygotic twinning.

    Science.gov (United States)

    Sparks, Amy E

    2012-01-01

    The incidence of monozygotic twinning in pregnancies achieved with assisted reproductive technologies (ART) is significantly higher than spontaneously conceived pregnancies. The factors associated with ART that predispose the embryos to splitting are not well-characterized. Assisted hatching and extended embryo culture are two ART laboratory methods that have been risk factors for monozygotic twinning. The methods and strategies that may be employed to avoid monozygotic twinning are discussed in this chapter.

  6. Genetic control of identity and growth in the early Arabidopsis embryo

    NARCIS (Netherlands)

    Weijers, D.

    2014-01-01

    Plants can grow complex and elaborate structures, in some species for thousands of years. Despite the diversity in form and shape, plants are built from a limited number of fundamental tissue types, and their arrangement is deeply conserved in the plant kingdom. A key question in biology is how thes

  7. 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

  8. 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.

  9. Zebrafish embryo model of Bartonella henselae infection.

    Science.gov (United States)

    Lima, Amorce; Cha, Byeong J; Amin, Jahanshah; Smith, Lisa K; Anderson, Burt

    2014-10-01

    Bartonella henselae (Bh) is an emerging zoonotic pathogen that has been associated with a variety of human diseases, including bacillary angiomatosis that is characterized by vasoproliferative tumor-like lesions on the skin of some immunosuppressed individuals. The study of Bh pathogenesis has been limited to in vitro cell culture systems due to the lack of an animal model. Therefore, we wanted to investigate whether the zebrafish embryo could be used to model human infection with Bh. Our data showed that Tg(fli1:egfp)(y1) zebrafish embryos supported a sustained Bh infection for 7 days with >10-fold bacterial replication when inoculated in the yolk sac. We showed that Bh recruited phagocytes to the site of infection in the Tg(mpx:GFP)uwm1 embryos. Infected embryos showed evidence of a Bh-induced angiogenic phenotype and an increase in the expression of genes encoding pro-inflammatory factors and pro-angiogenic markers. However, infection of zebrafish embryos with a deletion mutant in the major adhesin (BadA) resulted in little or no bacterial replication and a diminished host response, providing the first evidence that BadA is critical for in vivo infection. Thus, the zebrafish embryo provides the first practical model of Bh infection that will facilitate efforts to identify virulence factors and define molecular mechanisms of Bh pathogenesis.

  10. Manipulation and imaging of Kryptolebias marmoratus embryos.

    Science.gov (United States)

    Mourabit, Sulayman; Kudoh, Tetsuhiro

    2012-12-01

    The self-fertilizing mangrove killifish, Kryptolebias marmoratus, is an upcoming model species for a range of biological disciplines. To further establish this model in the field of developmental biology, we examined several techniques for embryonic manipulation and for imaging that can be used in an array of experimental designs. These methodological approaches can be divided into two categories: handling of embryos with and without their chorionic membrane. Embryos still enclosed in their chorion can be manipulated using an agarose bed or a methyl cellulose system, holding them in place and allowing their rotation to more specific angles and positions. Using these methods, we demonstrate microinjection of embryos and monitoring of fluorescent yolk syncytial nuclei (YSN) using both stereo and compound microscopes. For higher magnification imaging using compound microscopes as well as time-lapse analyses, embryos were dechorionated and embedded in low-melting-point agarose. To demonstrate this embedding technique, we further examined fluorescent YSN and also analyzed the yolk surface of K. marmoratus embryos. The latter was observed to provide an excellent imaging platform for study of the behavior and morphology of cells during embryonic development, for various types of cells. Our data demonstrate that K. marmoratus is an excellent model species for research in developmental biology, as methodological approaches for the manipulation and imaging of embryos are efficient and readily available.

  11. Arabidopsis haiku mutants reveal new controls of seed size by endosperm.

    Science.gov (United States)

    Garcia, Damien; Saingery, Virginie; Chambrier, Pierre; Mayer, Ulrike; Jürgens, Gerd; Berger, Frédéric

    2003-04-01

    In flowering plants, maternal seed integument encloses the embryo and the endosperm, which are both derived from double fertilization. Although the development of these three components must be coordinated, we have limited knowledge of mechanisms involved in such coordination. The endosperm may play a central role in these mechanisms as epigenetic modifications of endosperm development, via imbalance of dosage between maternal and paternal genomes, affecting both the embryo and the integument. To identify targets of such epigenetic controls, we designed a genetic screen in Arabidopsis for mutants that phenocopy the effects of dosage imbalance in the endosperm. The two mutants haiku 1 and haiku 2 produce seed of reduced size that resemble seed with maternal excess in the maternal/paternal dosage. Homozygous haiku seed develop into plants indistinguishable from wild type. Each mutation is sporophytic recessive, and double-mutant analysis suggests that both mutations affect the same genetic pathway. The endosperm of haiku mutants shows a premature arrest of increase in size that causes precocious cellularization of the syncytial endosperm. Reduction of seed size in haiku results from coordinated reduction of endosperm size, embryo proliferation, and cell elongation of the maternally derived integument. We present further evidence for a control of integument development mediated by endosperm-derived signals.

  12. Miniaturized embryo array for automated trapping, immobilization and microperfusion of zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Jin Akagi

    Full Text Available Zebrafish (Danio rerio has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP. The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale.

  13. Embryo quality and transcervical technique are not the limiting factors in donkey embryo transfer outcome.

    Science.gov (United States)

    Panzani, D; Rota, A; Crisci, A; Kindahl, H; Govoni, N; Camillo, F

    2012-02-01

    Embryo transfer (ET) in the donkey resulted in a very low recipient pregnancy rates. The aim of these studies was to investigate if nonsurgical transfer techniques or donkey embryo quality affect donkey recipient pregnancy failure. In Study 1, the impact of transfer technique was investigated by evaluating if cervical catheterization is associated with prostaglandin release and suppression of luteal function and if donkey recipients would become pregnant after nonsurgical transfer of horse embryos. Four jennies, from 5 to 8 d after ovulation, were submitted to a sham transcervical ET and to evaluation of PGFM and progesterone plasma concentrations. Five 8 d horse embryos were nonsurgically transferred into synchronized donkey recipients (HD). Cervical stimulation caused a transient PGF(2α) release in two of four jennies in the absence of a significant decrease in progesterone plasma concentration. All transferred horse embryos resulted in pregnancies in the jenny recipients. In Study 2, donkey embryo viability was investigated by 1.2 meters, 6-diamidino-2-phenylindole (DAPI) staining of 10 embryos and by the transfer of 6 and 12 donkey embryos in synchronized mare (DH) and donkey (DD) recipients, respectively, of known fertility. The estimated proportion of dead cells in DAPI stained embryos was 0.9% (range 0-3.9%) and below what is considered normal (20%) for horse embryos. Three of six and six of 12 of the DH and DD ETs, respectively resulted in pregnancies at 14 and 25 d (50%), a higher pregnancy rate than previously reported after DD ET. The overall results of this study suggest that the transcervical technique for ET and donkey embryo viability are not the reasons for the low pregnancy rates that have previously been described in donkey recipients, and that nonsurgical ET in donkeys can result in acceptable results.

  14. Jasmonate Signal Pathway in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yi Shan; Zhi-Long Wang; Daoxin Xie

    2007-01-01

    Jasmonates (JAs), which include jasmonic acid and its cyclopentane derivatives are synthesized from the octadecanoid pathway and widely distributed throughout the plant kingdom. JAs modulate the expression of numerous genes and mediate responses to stress, wounding, insect attack, pathogen infection, and UV damage. They also affect a variety of processes in many plant developmental processes. The JA signal pathway involves two important events: the biosynthesis of JA and the transduction of JA signal. Several important Arabidopsis mutants in jasmonate signal pathway were described in this review.

  15. 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.

  16. Systematic analysis of protein subcellular localization and interaction using high-throughput transient transformation of Arabidopsis seedlings.

    Science.gov (United States)

    Marion, Jessica; Bach, Lien; Bellec, Yannick; Meyer, Christian; Gissot, Lionel; Faure, Jean-Denis

    2008-10-01

    The functional genomics approach requires systematic analysis of protein subcellular distribution and interaction networks, preferably by optimizing experimental simplicity and physiological significance. Here, we present an efficient in planta transient transformation system that allows single or multiple expression of constructs containing various fluorescent protein tags in Arabidopsis cotyledons. The optimized protocol is based on vacuum infiltration of agrobacteria directly into young Arabidopsis seedlings. We demonstrate that Arabidopsis epidermal cells show a subcellular distribution of reference markers similar to that in tobacco epidermal cells, and can be used for co-localization or bi-molecular fluorescent complementation studies. We then used this new system to investigate the subcellular distribution of enzymes involved in sphingolipid metabolism. In contrast to transformation systems using tobacco epidermal cells or cultured Arabidopsis cells, our system provides the opportunity to take advantage of the extensive collections of mutant and transgenic lines available in Arabidopsis. The fact that this assay uses conventional binary vectors and a conventional Agrobacterium strain, and is compatible with a large variety of fluorescent tags, makes it a versatile tool for construct screening and characterization before stable transformation. Transient expression in Arabidopsis seedlings is thus a fast and simple method that requires minimum handling and potentially allows medium- to high-throughput analyses of fusion proteins harboring fluorescent tags in a whole-plant cellular context.

  17. Automatic Quantification of the Number of Intracellular Compartments in Arabidopsis thaliana Root Cells

    Science.gov (United States)

    Bayle, Vincent; Platre, Matthieu Pierre; Jaillais, Yvon

    2017-01-01

    In the era of quantitative biology, it is increasingly required to quantify confocal microscopy images. If possible, quantification should be performed in an automatic way, in order to avoid bias from the experimenter, to allow the quantification of a large number of samples, and to increase reproducibility between laboratories. In this protocol, we describe procedures for automatic counting of the number of intracellular compartments in Arabidopsis root cells, which can be used for example to study endocytosis or secretory trafficking pathways and to compare membrane organization between different genotypes or treatments. While developed for Arabidopsis roots, this method can be used on other tissues, cell types and plant species. PMID:28255574

  18. 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...

  19. Meanings of the embryo in Japan: narratives of IVF experience and embryo ownership

    NARCIS (Netherlands)

    Kato, M.; Sleeboom-Faulkner, M.

    2011-01-01

    This article explores the sociocultural meanings of the embryo implied in the narratives of 58 women who have undergone in vitro fertilisation in Japan over a period from 2006 to 2008. We argue that a lack of sufficient analysis of the sociocultural meanings of the embryo result in a situation where

  20. Reference: 572 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available et al. 2007 May. Plant J. 50(3):439-51. Although glycine-rich RNA-binding protein 2 (GRP2) has been implicated in plant re...sponses to environmental stresses, the function and importance of GRP2 in stress responses are largely unknown. Here...haliana under high-salinity, cold or osmotic stress. GRP2 affects seed germination of Arabidopsis plants under salt stre...ss, but does not influence seed germination and seedling growth of Arabidopsis plants under osmotic stre...ss. GRP2 accelerates seed germination and seedling growth in Arabidopsis plants under cold stre

  1. Comparison of the major malformation rate of children conceived from cryopreserved embryos and fresh embryos

    Institute of Scientific and Technical Information of China (English)

    LI Hong-zhen; QIAO Jie; CHI Hong-bin; CHEN Xin-na; LIU Ping; MA Cai-hong

    2010-01-01

    Background Cryopreserved embryo transfer has become indispensable in reproductive technology. More and more children are conceived from frozen-thawed embryo transfer (FET). The risk of birth defects associated with frozen-thawed embryo transfer has been evaluated and conflict results are obtained. The aim of this study was to compare the rate of major malformations in children conceived from cryopreserved embryos with that of children from fresh embryos. Methods A retrospective analysis was performed on children conceived from frozen-thawed embryos and fresh embryos between January 2005 and December 2008 at the Reproduction Center of the Third Hospital, Peking University.The major malformation rates were compared between two groups for all children, as well as singletons or twins,separately. The frequencies of different subtypes of malformations classified according to different organ system were also compared.Results Thirty-four of 3125 children from cryopreserved embryos had a major malformation. The malformation rate was 1.09%, which was comparable to that for children after fresh embryos transfer (1.53%(55/3604), OR:0.71, 95% CI; 0.46-1.09). The malformation rate was also similar when the analysis was limited to children from cryopreserved embryos resulted from in vitro fertilization (IVF)(1.39%)and fresh IVF(1.3%). However, children from cryopreserved embryos resulted from intracytoplasmic sperm injections (ICSI) had much lower malformation rate than from fresh ICSI(0.63% vs.1.83%, OR: 0.34, 95% CI: 0.16-0.75). No difference was found in the incidence of major malformations in singletons from cryo ICSI (0.73%) and fresh ICS1(1.9%), or from cryo IVF(1.49%) and fresh IVF(1.67%). Similar malformation rate was found in multiples from cryo ICSI(0.52%) and fresh ICSI(1.76%), or cryo IVF(1.30%) and fresh IVF(0.90%). The distribution and risk of the subtype of malformations, such as cardiovascular, gastrointestinal, neural tube, urogenital, rnusculoskeletal and facial

  2. Developmental competence of porcine chimeric embryos produced by aggregation

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... 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...

  3. Development of interspecies cloned embryos in yak and dog.

    Science.gov (United States)

    Murakami, Masao; Otoi, Takeshige; Wongsrikeao, Pimprapar; Agung, Budiyanto; Sambuu, Rentsenkhand; Suzuki, Tatsuyuki

    2005-01-01

    Interspecies nuclear transfer (NT) could be an alternative to replicate animals when supply of recipient oocytes is limited or in vitro embryo production systems are incomplete. In the present study, embryonic development was assessed following interspecies NT of donor cumulus cells derived from yak and dog into the recipient ooplasm of domestic cow. The percentages of fusion and subsequent embryo development to the eight-cell stage of interspecies NT embryos were comparable to those of intraspecies NT embryos (cow-cow NT embryos). The percentage of development to blastocysts was significantly lower (p dog-cow NT embryos, only one embryo (0.4%) developed to the blastocyst stage. These results indicate that interspecies NT embryos possess equally developmental competence to the eight-cell stage as intraspecies NT embryos, but the development to blastocysts is very low when dog somatic cells are used as the donor nuclei.

  4. Cryopreservation of manipulated embryos: tackling the double jeopardy.

    Science.gov (United States)

    Dinnyes, A; Nedambale, T L

    2009-01-01

    The aim of the present review is to provide information to researchers and practitioners concerning the reasons for the altered viability and the medium- and long-term consequences of cryopreservation of manipulated mammalian embryos. Embryo manipulation is defined herein as the act or process of manipulating mammalian embryos, including superovulation, AI, IVM, IVF, in vitro culture, intracytoplasmic sperm injection, embryo biopsy or splitting, somatic cell nuclear transfer cloning, the production of sexed embryos (by sperm sexing), embryo cryopreservation, embryo transfer or the creation of genetically modified (transgenic) embryos. With advances in manipulation technologies, the application of embryo manipulation will become more frequent; the proper prevention and management of the resulting alterations will be crucial in establishing an economically viable animal breeding technology.

  5. Patients' Attitudes towards the Surplus Frozen Embryos in China

    Directory of Open Access Journals (Sweden)

    Xuan Jin

    2013-01-01

    Full Text Available Background. Assisted reproductive techniques have been used in China for more than 20 years. This study investigates the attitudes of surplus embryo holders towards embryos storage and donation for medical research. Methods. A total of 363 couples who had completed in vitro fertilization (IVF treatment and had already had biological children but who still had frozen embryos in storage were invited to participate. Interviews were conducted by clinics in a narrative style. Results. Family size was the major reason for participants’ (discontinuation of embryo storage; moreover, the moral status of embryos was an important factor for couples choosing embryo storage, while the storage fee was an important factor for couples choosing embryo disposal. Most couples discontinued the storage of their embryos once their children were older than 3 years. In our study, 58.8% of the couples preferred to dispose of surplus embryos rather than donate them to research, citing a lack of information and distrust in science as significant reasons for their decision. Conclusions. Interviews regarding frozen embryos, including patients’ expectations for embryo storage and information to assist them with decisions regarding embryo disposal, are beneficial for policies addressing embryo disposition and embryo donation in China.

  6. Bovine pretransfer endometrium and embryo transcriptome fingerprints as predictors of pregnancy success after embryo transfer.

    Science.gov (United States)

    Salilew-Wondim, Dessie; Hölker, Michael; Rings, Franca; Ghanem, Nasser; Ulas-Cinar, Mehmet; Peippo, Jaana; Tholen, Ernst; Looft, Christian; Schellander, Karl; Tesfaye, Dawit

    2010-07-07

    Aberrant gene expression in the uterine endometrium and embryo has been the major causes of pregnancy failure in cattle. However, selecting cows having adequate endometrial receptivity and embryos of better developmental competence based on the gene expression pattern has been a greater challenge. To investigate whether pretransfer endometrial and embryo gene expression pattern has a direct relation with upcoming pregnancy success, we performed a global endometrial and embryo transcriptome analysis using endometrial and embryo biopsy technology and the pregnancy outcome information. For this, endometrial samples were collected from Simmental heifers at day 7 and 14 of the estrous cycle, one cycle prior to embryo transfer. In the next cycle, blastocyst stage embryos were transferred to recipients at day 7 of the estrous cycle after taking 30-40% of the blastocyst as a biopsy for transcriptome analysis. The results revealed that at day 7 of the estrous cycle, the endometrial gene expression pattern of heifers whose pregnancy resulting in calf delivery was significantly different compared with those resulting in no pregnancy. These differences were accompanied by qualitative and quantitative alteration of major biological process and molecular pathways. However, the transcriptome difference was minimal between the two groups of animals at day 14 of the estrous cycle. Similarly, the transcriptome analysis between embryos biopsies that resulted in calf delivery and those resulted in no pregnancy revealed a total of 70 differentially expressed genes. Among these, the transcript levels of 32 genes including SPAG17, PF6, UBE2D3P, DFNB31, AMD1, DTNBP1, and ARL8B were higher in embryo biopsies resulting in calf delivery. Therefore, the present study highlights the potential of pretransfer endometrial and embryo gene expression patterns as predictors of pregnancy success in cattle.

  7. ROCK inhibition prevents early mouse embryo development.

    Science.gov (United States)

    Duan, Xing; Chen, Kun-Lin; Zhang, Yu; Cui, Xiang-Shun; Kim, Nam-Hyung; Sun, Shao-Chen

    2014-08-01

    ROCK is a Rho-GTPase effector that is important for actin assembly and is involved in various cellular functions, including cell contraction, migration, motility, and tumor cell invasion. In this study, we investigated ROCK expression and function during early mouse embryo development. Inhibiting ROCK by Y-27632 treatment at the zygote stage resulted in first cleavage failure, and most embryos failed to develop to the 8-cell stage. When adding Y-27632 at the 8-cell stage, embryos failed to undergo compaction and could not develop into blastocysts. In addition, fluorescence staining intensity analysis indicated that actin expression at blastomere membranes was significantly reduced. After ROCK inhibition, two or more nuclei were observed in a cell, which indicated possible cytokinesis failure. Moreover, after ROCK inhibition with Y-27632, the phosphorylation levels of LIMK1/2, a downstream molecule of ROCK, were decreased at blastomere membranes. Thus, our results showed conserved roles for ROCK in this mammalian embryo model and indicated that a ROCK-LIMK1/2-actin pathway might regulate cleavage and blastocyst formation during early mouse embryo development.

  8. Biosensors for detecting stress in developing embryos

    Science.gov (United States)

    Purdey, Malcolm S.; Saini, Avishkar; McLennan, Hanna J.; Pullen, Benjamin J.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Thompson, Jeremy G.; Monro, Tanya M.; Nicholls, Stephen J.; Abell, Andrew D.

    2016-12-01

    Reactive Oxygen Species (ROS) cause DNA damage and defective function in sperm and also affects the developmental competence of embryos. It is therefore critical to monitor ROS in sperm, oocytes and developing embryos. In particular, hydrogen peroxide (H2O2) is a ROS important to normal cell function and signalling as well as its role in oxidative stress. Here we report the development of a fluorescent sensor for H2O2 using carboxyperoxyfluor-1 (CPF1) in solution and attached to a glass slide or multi-mode optical fibre. CPF1 increases in fluorescence upon reaction with H2O2 to non-invasively detect H2O2 near developing embryos. These probes are constructed by immobilising CPF1 to the optical fibre tip a polyacrylamide layer. Also reported is a new dual optical fibre sensor for detecting both H2O2 and pH that is functional at biologically concentrations of H2O2 and can sense pH to 0.1 units. This research shows promise for the use of optical fibre sensors for monitoring the health of developing embryos. Furthermore, these sensors are applicable for use beyond embryos such as detecting stress in endothelial cells involved in cardiovascular dysfunction.

  9. In vitro culture of individual mouse preimplantation embryos: the role of embryo density, microwells, oxygen, timing and conditioned media.

    Science.gov (United States)

    Kelley, Rebecca L; Gardner, David K

    2017-02-15

    Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3.1; 110.2 ± 3.5) compared with group culture throughout (127.0 ± 3.4; P media volume from 20 µl to 2 µl increased blastocyst cell numbers in single embryos cultured in 5% oxygen (84.4 ± 3.2 versus 97.8 ± 2.8; P media to single embryos increased hatching rate and blastocyst cell number (91.5 ± 4.7 versus 113.1 ± 4.4; P media volume and microwells influence single embryo development; and embryo-conditioned media may substitute for group culture.

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. Reference: 488 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available Inactivation of ATAB2 strongly affects Arabidopsis development and thylakoid mem...n center subunits is decreased and the association of their mRNAs with polysomes is affected. ATAB2 is a chl

  16. Reference: 212 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available identified in pea (Pisum sativum) using biochemical approaches. The Arabidopsis (...C75-IV, which we studied using a range of molecular, genetic, and biochemical techniques. Expression of atTO

  17. Reference: 480 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available activity was analyzed. Compared to all other Suc transporters, AtSUC9 had an ult...abidopsis (Arabidopsis thaliana) L. Heynh., was expressed in Xenopus (Xenopus laevis) oocytes, and transport

  18. Reference: 507 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available een them. However, little is known about the mechanisms that regulate the two pathways and the metabolic cro...ss-talk. To identify such regulatory mechanisms, we isolated and characterized the Arabidopsis T-DNA inserti

  19. Reference: 278 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available functional ERA1 gene, which encodes the beta-subunit of protein farnesyltransferase (PFT), exhibit pleiotropic effects...gnaling and meristem development. Here, we report the effects of T-DNA insertion mutations in the Arabidopsi

  20. Reference: 185 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available organisms, we suggest that AtARP4 is likely to exert its effects on plant develop...nuclear actin-related protein AtARP4 in Arabidopsis has multiple effects on plant development, including ear

  1. Arabidopsis CDS blastp result: AK069960 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 5e-60 ...

  2. Arabidopsis CDS blastp result: AK064768 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-112 ...

  3. Arabidopsis CDS blastp result: AK061551 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 2e-67 ...

  4. Arabidopsis CDS blastp result: AK104764 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 2e-67 ...

  5. Arabidopsis CDS blastp result: AK098998 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 8e-57 ...

  6. Arabidopsis CDS blastp result: AK061859 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-100 ...

  7. Arabidopsis CDS blastp result: AK103387 [KOME

    Lifescience Database Archive (English)

    Full Text Available ntical to SC35-like splicing factor SCL28, 28 kD [Arabidopsis thaliana] GI:9843655; contains Pfam profile PF00076: RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain) 2e-34 ...

  8. Reference: 564 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available 39-44 17360695 2007 Feb Proceedings of the National Academy of Sciences of the Un...tion in plants. Arabidopsis plasma membrane protein crucial for Ca2+ influx and touch sensing in roots. 9 36

  9. Reference: 420 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available are found in various compartments in plant cells. The cytosolic and chloroplast APXs appear to play important...d development, suggesting that APX3 may not be an important antioxidant enzyme in Arabidopsis, at least unde

  10. Reference: 771 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available RCADIAN TIMEKEEPER (XCT), an Arabidopsis thaliana gene important for light regula...l elongation in xct is hyposensitive to red light but hypersensitive to blue light. Finally, XCT is important

  11. Reference: 797 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available that the level of GMPase activity regulates Arabidopsis sensitivity to NH(4)(+). Further analysis showed that defective N-glycosylati...on of proteins, unfolded protein response, and cell death in the roots are likely i

  12. Arabidopsis CDS blastp result: AK241712 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241712 J065197H24 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 6e-27 ...

  13. Arabidopsis CDS blastp result: AK242957 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242957 J090089I15 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 1e-28 ...

  14. Arabidopsis CDS blastp result: AK287726 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287726 J065138E17 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 1e-88 ...

  15. Arabidopsis CDS blastp result: AK242387 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242387 J080051E14 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 2e-45 ...

  16. Arabidopsis CDS blastp result: AK106306 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK106306 002-101-C10 At4g37750.1 ovule development protein aintegumenta (ANT) ident...ical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 3e-89 ...

  17. Arabidopsis CDS blastp result: AK241272 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241272 J065132I19 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 1e-88 ...

  18. Arabidopsis CDS blastp result: AK240892 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240892 J065030K10 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 5e-88 ...

  19. Arabidopsis CDS blastp result: AK109848 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK109848 002-148-F05 At4g37750.1 ovule development protein aintegumenta (ANT) ident...ical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 5e-73 ...

  20. Arabidopsis CDS blastp result: AK287673 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287673 J065121E18 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 6e-17 ...

  1. Arabidopsis CDS blastp result: AK287621 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287621 J065066I09 At4g37750.1 68417.m05344 ovule development protein aintegumenta... (ANT) identical to ovule development protein aintegumenta (ANT) (GI:1244708) ) [Arabidopsis thaliana] 5e-85 ...

  2. Reference: 142 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available te S-glucosyltransferase, UGT74B1, to determine its role in the Arabidopsis glucosinolate pathway. Biochem...ical analyses demonstrate that recombinant UGT74B1 specifically glucosylates the th

  3. Reference: 522 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available tol phosphate (InsP) and phosphoinositide phosphate (PtdInsP) substrates. Arabidopsis thaliana has 15 genes encoding 5PTases. Biochem...ical analyses of a subgroup of 5PTase enzymes suggest th

  4. Reference: 459 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available plants. These results suggest an additive contribution of AMT1;1 and AMT1;3 to the overall ammonium uptake ...capacity in Arabidopsis roots under nitrogen-deficiency conditions. Additive contribution

  5. 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 ...

  6. Reference: 645 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available rter AtDUR3 in nitrogen nutrition in Arabidopsis. In transgenic lines expressing ... impaired growth on urea as a sole nitrogen source were used to investigate a role of the H+/urea co-transpo

  7. 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.

  8. Reference: 711 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available of the RLK signaling pathway, which also mediates adaptation to Na(+) stress. RLK pathway components, known... The Arabidopsis kinase-associated protein phosphatase regulates adaptation to Na+ stress. 2 612-22 18162596

  9. Reference: 734 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available umi et al. 2008 Apr. Development 135(7):1335-45. CAPRICE (CPC) encodes a small protein with an R3 MYB motif ...doreduplication. Arabidopsis CAPRICE-LIKE MYB 3 (CPL3) controls endoreduplication and flowering development

  10. Arabidopsis CDS blastp result: AK101526 [KOME

    Lifescience Database Archive (English)

    Full Text Available ucosaminyltransferase, putative similar to N-acetylglucosaminyltransferase I from Arabidopsis thaliana [gi:5139335]; contains AT-AC non-consensus splice sites at intron 13 1e-179 ...

  11. Reference: 733 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available role in this transition. Specifically, two autonomous factors in the Arabidopsis...tes FCA alternative polyadenylation and promotes flowering as a novel factor in the autonomous pathway. Firs

  12. Reference: 343 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available the characterization of a T-DNA insertion mutant of the Arabidopsis CAP-C gene. Analysis of the progeny of selfe...matin was observed between segregating mitotic chromosomes in pollen produced by selfed heterozygotes. Addit

  13. Arabidopsis CDS blastp result: AK241281 [KOME

    Lifescience Database Archive (English)

    Full Text Available 2 protein) [Arabidopsis thaliana]; a false single bp exon was added to circumvent a single basepair insertion in the genomic sequence, supported by cDNA/genome alignment. 3e-19 ...

  14. Arabidopsis CDS blastp result: AK241243 [KOME

    Lifescience Database Archive (English)

    Full Text Available 2 protein) [Arabidopsis thaliana]; a false single bp exon was added to circumvent a single basepair insertion in the genomic sequence, supported by cDNA/genome alignment. 6e-11 ...

  15. Arabidopsis CDS blastp result: AK243188 [KOME

    Lifescience Database Archive (English)

    Full Text Available 2 protein) [Arabidopsis thaliana]; a false single bp exon was added to circumvent a single basepair insertion in the genomic sequence, supported by cDNA/genome alignment. 8e-23 ...

  16. Arabidopsis CDS blastp result: AK242986 [KOME

    Lifescience Database Archive (English)

    Full Text Available 2 protein) [Arabidopsis thaliana]; a false single bp exon was added to circumvent a single basepair insertion in the genomic sequence, supported by cDNA/genome alignment. 1e-17 ...

  17. Reference: 30 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ponse to various biotic and abiotic stresses. However the physiological role of t...his pathway remains obscure. To elucidate its role in plants, we analyzed Arabidopsis T-DNA knockout mutants

  18. Arabidopsis CDS blastp result: AK062082 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK062082 001-044-F11 At3g59970.3 methylenetetrahydrofolate reductase 1 (MTHFR1) ide...ntical to methylenetetrahydrofolate reductase MTHFR1 [Arabidopsis thaliana] GI:5911425 4e-81 ...

  19. Reference: 783 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available sis ACBP6 was confirmed by analyses of transgenic Arabidopsis expressing autofluorescence-tagged ACBP6 and w... mRNA encoding phospholipase Ddelta. Lipid profiling analyses of rosettes from co

  20. Reference: 789 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ylakoid membranes. Microarray analysis of the chl27-t mutant showed repression of numerous nuclear genes involved in photosynthesis...d CHL27 proteins. Role of Arabidopsis CHL27 protein for photosynthesis, chloroplast development and gene exp

  1. Reference: 352 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available em II and has a specific function distinct from 2-Cys peroxiredoxin in protecting photosynthesis. Its absenc...f Arabidopsis thaliana is attached to the thylakoids and functions in context of photosynthesis

  2. Reference: 21 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ication of a number of mutant lines with altered Chl fluorescence characteristics. Analysis of photosynthesis...cation of mutants of Arabidopsis defective in acclimation of photosynthesis to th

  3. Reference: 413 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ollination and fertilization, and, in the absence of fertilization, flowers senesce. In the Arabidopsis thal...ARF8 acts as an inhibitor to stop further carpel development in the absence of fertilization and the generat

  4. Reference: 405 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available as previously thought. These mutants will prove to be valuable resources for understanding laccase functions in vivo. Mutant identifi...cation and characterization of the laccase gene family in Arabidopsis. 11 2563-9 16

  5. Reference: 263 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available idopsis leaves GLB1 expression and PII protein levels were not significantly affected by either the day/nigh...bolism. Physiological characterisation of Arabidopsis mutants affected in the expression of the putative reg

  6. Reference: 160 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available excessive accumulation of these toxic compounds impairs cell death containment and counteracts the effect...iveness of the plant defenses to restrict pathogen infection. Arabidopsis SHMT1, a

  7. 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 ...

  8. Reference: 301 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available n phosphatidylinositol metabolism and is encoded by an At5PTase gene family in Arabidopsis thaliana. A previous study...ntracellular calcium levels. In this study, we provide evidence that At5PTase13 m

  9. Reference: 289 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available f flavonoids in Arabidopsis seed coat. 11 2966-80 16243908 2005 Nov The Plant cell Caboche Michel|Debeaujon Isabelle|Kerhoas Lucien|Lepiniec Loïc|Pourcel Lucille|Routaboul Jean-Marc

  10. Reference: 684 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available cellular proliferation and expansion at nanomolar concentrations. PSY1 is widely expressed in various Arabi...ulfated glycopeptide involved in cellular proliferation and expansion in Arabidopsis. 46 18333-8 17989228 20

  11. Reference: 147 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available the region-specific control of trichome development of Arabidopsis. 3 389-98 15604688 2004 May Plant molecular biology Hulskamp Mart...in|Kirik Victor|Schiefelbein John|Simon Marissa|Wester Katja

  12. 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

  13. 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

  14. Reference: 798 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available iption factors, control the delicately tuned reorientation and timing of cell div...EZ and SOMBRERO control the orientation of cell division plane in Arabidopsis root stem cells. 6 913-22 1908

  15. Distinct roles of ROCK1 and ROCK2 during development of porcine preimplantation embryos.

    Science.gov (United States)

    Zhang, Jin Yu; Dong, Huan Sheng; Oqani, Reza K; Lin, Tao; Kang, Jung Won; Jin, Dong Il

    2014-07-01

    Cell-to-cell contact mediated by cell adhesion is fundamental to the compaction process that ensures blastocyst quality during embryonic development. In this study, we first showed that Rho-associated coiled-coil protein kinases (ROCK1 and ROCK2) were expressed both in porcine oocytes and IVF preimplantation embryos, playing different roles in oocytes maturation and embryo development. The amount of mRNA encoding ROCK1 and the protein concentration clearly increased between the eight-cell and morula stages, but decreased significantly when blastocysts were formed. Conversely, ROCK2 was more abundant in the blastocyst compared with other embryonic stages. Moreover, immunostaining showed that ROCK1 protein distribution changed as the embryo progressed through cleavage and compaction to the morula stage. Initially, the protein was predominantly associated with the plasma membrane but later became cytoplasmic. By contrast, ROCK2 protein was localized in both the cytoplasm and the spindle rotation region during oocyte meiosis, but in the cytoplasm and nucleus as the embryo developed. In addition, ROCK2 was present in the trophectoderm cells of the blastocyst. Treatment with 15 μM Y27632, a specific inhibitor of ROCKs, completely blocked further development of early four-cell stage embryos. Moreover, we did not detect the expression of ROCK1 but did detect ROCK2 expression in blastocysts. Moreover, lysophosphatidic acid an activator of ROCKs significantly improved the rates of blastocyst formation. These data demonstrate that ROCKs are required for embryo development to the blastocyst stage. Together, our results indicate that ROCK1 and ROCK2 may exert different biological functions during the regulation of compaction and in ensuring development of porcine preimplantation embryos to the blastocyst stage.

  16. Accuracy of a combined score of zygote and embryo morphology for selecting the best embryos for IVF

    Institute of Scientific and Technical Information of China (English)

    Yu-li QIAN; Ying-hui YE; Chen-ming XU; Fan JIN; He-feng HUANG

    2008-01-01

    Objective:To evaluate the accuracy of a scoring system combining zygote and embryo morphology in predicting the outcome of in vitro fertilization(IVF)treatment.Methods:In a study group,117 consecutive IVF or intracytoplasmic sperm injection(ICSI) cycles with embryo transfer were carried out and 312 embryos were scored Using a combmed scoring system(CSS)of zygote and embryo morphology before transplantation.In a control group,a total of 420 IVF or ICSI cycles were carried out and 1176 embryos were scored using a cumulative embryo score(CES).The effects of the combined scoring system on the embryo implantation rate and pregnancy rate per cycle were analyzed.Results:Using the combined scoring system,the embryo implantation rate(27.6%)and the clinical pregnancy rate(48.7%)were significantly higher than those in the control group(20.8%and 38.6%,respectively).Also,the implantation rate of embryos scoring≥70 (38.5%:82 sacs/213 embryos)was significantly higher (P<0.001)than that of embryos scoring<70(4%:4 sacs/99 embryos).The pregnancy rate of patients with embryos scoring≥70 using the combined scoring system(66.7%)Was significantly higher(P<0.001)than that of patients with embryos scoring≥20 using the cumulative embryo score(59.0%).Conclusion:The results suggest that selecting embryos with a high Score(≥70)using the combined scoring system could inerease the implantation rate and pregnancy rate,and that using a scoring system combining assessments of human zygotes and pre-implantation embryos might predict IVF outcomes more accurately than using a cumulafive embryo score.

  17. Efficacy of in vitro embryo transfer in lactating dairy cows using fresh or vitrified embryos produced in a novel embryo culture medium.

    Science.gov (United States)

    Block, J; Bonilla, L; Hansen, P J

    2010-11-01

    Objectives were to determine whether pregnancy success could be improved in lactating cows with timed embryo transfer when embryos were produced in vitro using a medium designed to enhance embryo development and survival after cryopreservation. In experiment 1, embryos (n=569 to 922) were cultured in either modified synthetic oviduct fluid or a serum-free medium, Block-Bonilla-Hansen-7 (BBH7). Development to the blastocyst stage was recorded at d 7, and selected blastocysts (n=79 to 114) were vitrified using open pulled straws. Culture of embryos in BBH7 increased development to the blastocyst stage (41.9±2.0 vs. 14.7±2.0%) and advanced blastocyst stages (expanded, hatching, hatched; 31.1±1.3 vs. 6.4±1.3%) at d 7 and resulted in higher hatching rates at 24h postwarming compared with embryos cultured in modified synthetic oviduct fluid (59.0±0.5 vs. 26.7±0.5%). In experiment 2, embryos were produced using X-sorted semen and cultured in BBH7. At d 7 after insemination, embryos were transferred fresh or following vitrification. Lactating Holstein cows were either subjected to timed artificial insemination (TAI) on the day of presumptive ovulation or used as embryo recipients 7 d later. Embryo recipients received an embryo if a corpus luteum was present. The percentage of cows pregnant at d 32, 46, and 76 of gestation was higher among cows that received fresh embryos compared with TAI cows or cows that received vitrified embryos. At d 76, for example, the proportion and percentage pregnant was 47/150 (31.3%) for cows subjected to TAI, 48/95 (50.5%) for cows receiving fresh embryos, and 39/141 (27.7%) for cows receiving a vitrified embryo. No difference was observed in the percentage of cows pregnant among TAI cows and those that received vitrified embryos. There was a service or transfer number × treatment interaction because differences in pregnancy rate between embryo transfer recipients and cows bred by TAI were greater for cows with more than 3 services or

  18. Arabidopsis CDS blastp result: AK071710 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK071710 J023110L07 At4g14030.1 selenium-binding protein, putative contains Pfam profile PF05694: 56kDa sele...nium binding protein (SBP56); identical to Putative selenium-binding protein (Swiss...-Prot:O23264) [Arabidopsis thaliana]; similar to selenium binding protein (GI:15485232) [Arabidopsis thalian...a]; identical to cDNA from partial mRNA for selenium binding protein (sbp gene) GI:15485231 1e-162 ...

  19. Reference: 598 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available omoter is markedly reduced in the cdkc;2 and cyct1;5 mutants, indicating that the kinase complexes are important... flowering. These results establish Arabidopsis CDKC kinase complexes as important...T1;4 and CYCT1;5, play important roles in infection with Cauliflower mosaic virus...hat Arabidopsis thaliana CDK9-like proteins, CDKC;1 and CDKC;2, and their interacting cyclin T partners, CYC

  20. Chromatin associations in Arabidopsis interphase nuclei

    Directory of Open Access Journals (Sweden)

    Veit eSchubert

    2014-11-01

    Full Text Available The arrangement of chromatin within interphase nuclei seems to be caused by topological constraints and related to gene expression depending on tissue and developmental stage. In yeast and animals it was found that homologous and heterologous chromatin association are required to realize faithful expression and DNA repair. To test whether such associations are present in plants we analysed Arabidopsis thaliana interphase nuclei by FISH using probes from different chromosomes. We found that chromatin fibre movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances. The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns.Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its ten centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus. Nevertheless, chromatin movement enables a flexible spatial genome arrangement in plant nuclei.