Sample records for somatic embryogenesis induction

  1. Direct induction of cotton somatic embryogenesis

    Microsoft Academic Search

    Baohong Zhang; Rong Feng; Fang Liu; Changbing Yao

    1999-01-01

    COMPARED with indirect somatic embryogenesis, direct somatic embryogenesis appears to be associated with greater genetic and cytological uniformity, and it takes less time to induce direct embryogenesis than indirect embryogenesis. Although cotton somatic embryogenesis has been reported by many scientists, direct somatic embryogenesis has not been reported yetr'; . This letter first describes the induction of direct somatic embryogenesis and

  2. Callus induction and somatic embryogenesis of Phalaenopsis

    Microsoft Academic Search

    Y. Ishii; T. Takamura; M. Goi; M. Tanaka

    1998-01-01

    Callus induction and plant regeneration through somatic embryogenesis in Phalaenopsis Richard Shaffer `Santa Cruz' were examined. Protocorm-like body (PLB) segments formed calli in Vacin and Went medium with\\u000a sucrose. The optimal concentration of sucrose was 40 g ? l–1. Medium containing 200 ml ? l–1 coconut water together with 40 g ? l–1 sucrose was effective for callus induction. Gellan

  3. Induction of somatic embryogenesis and DNA fingerprinting of Jojoba

    Microsoft Academic Search

    Ahmed Gaber; Heba M. M. El-Maraghy; M. A. M. Aly; Nahed A. K. Rashed; A. Y. Gamal El-Din

    In-vitro induction of somatic embryogenesis and regeneration ability of jojoba (Simmondsia chinensis (Link) Schneider) plant were investigated using two different types of explants, i.e., immature zygotic embryos and leaf disks, and different culture media. Compact embryogenic callus was induced on Murashige and Skoog (MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and sucrose. Embryogenic callus was developed from

  4. Induction of somatic embryogenesis and adventitious shoots from immature leaves of cassava

    Microsoft Academic Search

    Guohua Ma; Qiusheng Xu

    2002-01-01

    Direct somatic embryogenesis was successfully achieved from immature leaves of cassava (Manihot esculenta Crantz) cultured on induction medium containing 2,4-dichlorophenoxyacetic acid or naphthaleneacetic acid. Changing the duration of induction or changing plant growth regulators resulted in differences in regeneration of somatic embryos or adventitious shoots. The results showed that auxin was a key factor for inducing embryogenic cells. The embryogenic

  5. Improvements in somatic embryogenesis protocol in Feijoa ( Acca sellowiana (Berg) Burret): Induction, conversion and synthetic seeds

    Microsoft Academic Search

    Gabriela Claudia Cangahuala-Inocente; Lírio Luiz Dal Vesco; Douglas Steinmacher; Antonio Carlos Torres; Miguel Pedro Guerra

    2007-01-01

    Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology

  6. Cellular and molecular changes associated with somatic embryogenesis induction in Agave tequilana.

    PubMed

    Portillo, L; Olmedilla, A; Santacruz-Ruvalcaba, F

    2012-10-01

    In spite of the importance of somatic embryogenesis for basic research in plant embryology as well as for crop improvement and plant propagation, it is still unclear which mechanisms and cell signals are involved in acquiring embryogenic competence by a somatic cell. The aim of this work was to study cellular and molecular changes involved in the induction stage in calli of Agave tequilana Weber cultivar azul in order to gain more information on the initial stages of somatic embryogenesis in this species. Cytochemical and immunocytochemical techniques were used to identify differences between embryogenic and non-embryogenic cells from several genotypes. Presence of granular structures was detected after somatic embryogenesis induction in embryogenic cells; composition of these structures as well as changes in protein and polysaccharide distribution was studied using Coomassie brilliant blue and Periodic Acid-Schiff stains. Distribution of arabinogalactan proteins (AGPs) and pectins was investigated in embryogenic and non-embryogenic cells by immunolabelling using anti-AGP monoclonal antibodies (JIM4, JIM8 and JIM13) as well as an anti-methyl-esterified pectin-antibody (JIM7), in order to evaluate major modifications in cell wall composition in the initial stages of somatic embryogenesis. Our observations pointed out that induction of somatic embryogenesis produced accumulation of proteins and polysaccharides in embryogenic cells. Presence of JIM8, JIM13 and JIM7 epitopes were detected exclusively in embryogenic cells, which supports the idea that specific changes in cell wall are involved in the acquisition of embryogenic competence of A. tequilana. PMID:22270826

  7. A new approach to direct somatic embryogenesis in Medicago

    Microsoft Academic Search

    P. Denchev; M. Velcheva; A. Atanassov

    1991-01-01

    A highly efficient system for direct somatic embryogenesis is described. Leaf sections originating from young trifoliate leaves of Medicago falcata line 47\\/1–5 and Medicago sativa line No2\\/9R, directly produced embryos after cultivation in liquid B5IV induction medium. In comparison with indirect somatic embryogenesis the system omits the callus stage and thus allows shortening of the process of somatic embryogenesis in

  8. Mode of Action of Plant Hormones and Plant Growth Regulators During Induction of Somatic Embryogenesis: Molecular Aspects

    Microsoft Academic Search

    Clément Thomas; Víctor Jiménez

    Plant hormones play critical roles in the establishment of somatic embryogenesis. During this\\u000a process, somatic plant cells reverse their state of differentiation, acquire pluripotentiality and\\u000a set up a new developmental program. The identification of the regulatory mechanisms that govern\\u000a the key events of somatic embryogenesis requires molecular and genetic investigations. One critical\\u000a issue is how plant hormones and growth regulators act

  9. Induction of somatic embryogenesis in endangered butterfly ginger Hedychium coronarium J. Koenig.

    PubMed

    Verma, Manju; Bansal, Y K

    2012-12-01

    An efficient protocol has been developed for regeneration of complete plants through somatic embryogenesis in H. coronarium. Creamish white, pale yellow and brown calli were obtained on MS medium supplemented with different concentrations of auxins [2, 4-Dichlorophenoxy acetic acid (2, 4-D), Indole-3 acetic acid (IAA) and 1-Naphthylacetic acid (NAA)] after 4 weeks. Creamy white calli developed on 0.5 mg L(-1) 2, 4-D turned embryogenic when subcultured on basal medium and produced small globular somatic embryos after 6 weeks. Further growth of somatic embryos required their transfer to medium containing 6-benzylaminopurine (BAP) or kinetin (KN). BAP was more effective than KN in promoting shoot proliferation. Maximum shoot length was obtained with 0.5 mg L(-1) BAP whereas maximum shoot number was obtained with 1.0 mg L(-1) BAP. The plantlets thus formed were successfully hardened, and transferred to sand-soil and farm yard manure (1:1:1) with 95% survival. PMID:23986975

  10. Embryo production through somatic embryogenesis can be used to study cell differentiation in plants

    Microsoft Academic Search

    Francisco R. Quiroz-Figueroa; Rafael Rojas-Herrera; Rosa M. Galaz-Avalos; Víctor M. Loyola-Vargas

    2006-01-01

    Somatic embryogenesis is the process by which somatic cells, under induction conditions, generate embryogenic cells, which go through a series of morphological and biochemical changes that result in the formation of a somatic embryo. Somatic embryogenesis differs from zygotic embryogenesis in that it is observable, its various culture conditions can be controlled, and a lack of material is not a

  11. Dynamics of the concentration of IAA and some of its conjugates during the induction of somatic embryogenesis in Coffea canephora

    PubMed Central

    Ayil-Gutiérrez, Benajmín; Galaz-Ávalos, Rosa María; Peña-Cabrera, Eduardo; Loyola-Vargas, Victor Manuel

    2013-01-01

    Most of the somatic embryogenesis (SE) process requires the presence, either before or during the embryogenic process, of at least one exogenous auxin. This exogenous auxin induces the presence of endogenous auxins, which appears to be essential for SE induction. We found that during the preincubation period of SE in Coffea canephora, there is an important increase in both free and conjugated indole-3-acetic acid (IAA), as well as indole-3-butyric acid. This increase is accompanied by an increase in the expression of YUCCA (CcYUC), TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (CcTAA1), and GRETCHEN HAGEN 3 (GH3) genes. On the other hand, most of the IAA compounds decreased during the induction of SE. The results presented in this research suggest that a balance between free IAA and its amide conjugates is necessary to allow the expression of SE-related genes. PMID:24299659

  12. Diphenylurea Derivatives Induce Somatic Embryogenesis in Citrus

    Microsoft Academic Search

    Angela Carra; Fabio De Pasquale; Ada Ricci; Francesco Carimi

    2006-01-01

    The present research investigates the possibility that three diphenylurea (DPU) derivatives, N-phenyl-N?-benzothiazol-6-ylurea (PBU), N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU) and N,N?-bis-(3,4-methilendioxyphenyl)urea (3,4-MDPU), stimulate the induction of somatic embryogenesis in three Citrus species. The hypothetical embryogenic activity was assessed using stigma and styles of Citrus myrtifolia Raf., Citrus madurensis Lour. and Citrus limon (L.) Burm. The three compounds influenced the production of somatic embryos differently

  13. Somatic embryogenesis from isolated scutella of wheat: effects of physical, physiological and genetic factors

    Microsoft Academic Search

    Olivier C. Maës; Ravindra N. Chibbar; Karen Caswell; Nicholas Leung; Kutty K. Kartha

    1996-01-01

    Induction of high frequency somatic embryogenesis from in vitro culture of isolated scutella has been referred to as the Enhanced Regeneration System (ERS). In the present study, the importance of such factors as genotype, culture medium, explant size and cold pretreatment in the induction of somatic embryogenesis and regeneration response of isolated scutella was assessed in a complete block design

  14. Somatic embryogenesis and plantlet regeneration in mango ( Mangifera indica L.)

    Microsoft Academic Search

    Lilian F. Pateña; Luzminda R. Carlos-Refuerzo; Ramon C. Barba

    2002-01-01

    Summary  The ‘Carabao’ or ‘Manila Super’ mango (Mangifera indica L.), a virtually neglected fruit before the advent of KNO3 flower induction in the early 1970s, is now the third leading Philippine export fruit after banana and pineapple. To apply\\u000a biotechnology for improvement, a reliable embryogenesis and regeneration protocol is required. We have developed a protocol\\u000a for somatic embryogenesis and plantlet regeneration

  15. Protocols for efficient repetitive and secondary somatic embryogenesis in Helianthus maximiliani (Schrader)

    Microsoft Academic Search

    D. Vasic; G. Alibert; D. Skoric

    2001-01-01

    Indirect somatic embryogenesis was induced on leaf explants of greenhouse-grown Helianthus maximiliani plants. Leaves of the regenerated plants were used as starting explants for the induction of direct somatic embryogenesis.\\u000a Another cycle of somatic embryogenesis was induced on the leaves of regenerated plants. In both cases, leaf explants were\\u000a cultured on media containing different auxin\\/cytokinin ratios. The auxin\\/cytokinin ratio had

  16. Induction of somatic embryogenesis in explants of shoot cultures established from adult Eucalyptus globulus and E. saligna?×?E. maidenii trees.

    PubMed

    Corredoira, E; Ballester, A; Ibarra, M; Vieitez, A M

    2015-06-01

    A reproducible procedure for induction of somatic embryogenesis (SE) from adult trees of Eucalyptus globulus Labill. and the hybrid E. saligna Smith?×?E. maidenii has been developed for the first time. Somatic embryos were obtained from both shoot apex and leaf explants of all three genotypes evaluated, although embryogenic frequencies were significantly influenced by the species/genotype, auxin and explant type. Picloram was more efficient for somatic embryo induction than naphthaleneacetic acid (NAA), with the highest frequency of induction being obtained in Murashige and Skoog medium containing 40?µM picloram and 40?mg?l(-1) gum Arabic, in which 64% of the shoot apex explants and 68.8% of the leaf explants yielded somatic embryos. The embryogenic response of the hybrid was higher than that of the E. globulus, especially when NAA was used. The cultures initiated on picloram-containing medium consisted of nodular embryogenic structures surrounded by a mucilaginous coating layer that emerged from a watery callus developed from the initial explants. Cotyledonary somatic embryos were differentiated after subculture of these nodular embryogenic structures on a medium lacking plant growth regulators. Histological analysis confirmed the bipolar organization of the somatic embryos, with shoot and root meristems and closed procambial tissue that bifurcated into small cotyledons. The root pole was more differentiated than the shoot pole, which appeared to be formed by a few meristematic layers. Maintenance of the embryogenic lines by secondary SE was attained by subculturing individual cotyledonary embryos or small clusters of globular and torpedo embryos on medium with 16.11?µM NAA at 4- to 5-week intervals. Somatic embryos converted into plantlets after being transferred to liquid germination medium although plant regeneration remained poor. PMID:25877768

  17. Plant regeneration via somatic embryogenesis in Schlumbergera truncata

    Microsoft Academic Search

    Ezz Al-Dein Al-Ramamneh; Sridevy Sriskandarajah; Margrethe Serek

    2006-01-01

    Somatic embryogenesis was induced from phylloclade explants of Schlumbergera truncata cv. Russian Dancer. Callus developed on phylloclade explants and sub-cultured over a period of 16 months on MS medium containing\\u000a mainly cytokinins was superior for the induction of somatic embryos compared to callus grown for a shorter time in the establishment\\u000a medium. Sub-culture of callus grown in SH-or MS-based liquid media

  18. Influence of Boron on Somatic Embryogenesis in Papaya

    Microsoft Academic Search

    N. Renukdas; M. L. Mohan; S. S. Khuspe; S. K. Rawal

    2003-01-01

    Influence of boron on somatic embryogenesis in papaya (Carica papaya L.) cv. Honey Dew was investigated. Immature zygotic embryos were grown in the induction medium containing Murashige and\\u000a Skoog basal salts, with B5 vitamins, picloram (1 mg dm?3) or 2,4-dichlorophenoxy acetic acid (2 mg dm?3) and different concentrations of boric acid (30 to 500 mg dm?3). Maximum somatic embryo initiation

  19. Immuno-cytochemical localization of indole-3-acetic acid during induction of somatic embryogenesis in cultured sunflower embryos

    Microsoft Academic Search

    Clément Thomas; Roberte Bronner; Jean Molinier; Els Prinsen; Harry van Onckelen; Günther Hahne

    2002-01-01

    Immature zygotic embryos of sunflower (Helianthus annuus L.) produce somatic embryos when cultured on medium supplemented with a cytokinin as the sole source of exogenous growth regulators. The timing of the induction phase and subsequent morphogenic events have been well characterized in previous work. We address here the question of the role of endogenous indole-3-acetic acid (IAA), since auxins are

  20. Somatic embryogenesis in wild cherry (Prunus avium)

    Microsoft Academic Search

    Elisabeth Garin; Emmanuel Grenier; Ghislaine Grenier-De March

    1997-01-01

    Indirect somatic embryogenesis was obtained inPrunus avium L. from either somatic or zygotic embryos. An embryogenic line\\u000a was established by reinduction of embryogenic calluses from somatic embryos. The line was maintained for more than 3 years\\u000a through 6 generations of embryogenic cultures. In the last 2 generations, more than 50% of the explants were embryogenic.\\u000a Embryos at different stages of

  1. Effects of different concentrations of 2,4-D and BAP on somatic embryogenesis induction in saffron (Crocus sativus L.).

    PubMed

    Rajabpoor, Sh; Azghandi, A V; Saboora, A

    2007-11-01

    To optimize an in vitro protocol for propagation of saffron through somatic embryogenesis, effects of various concentrations of 2,4-D ( 0, 0.25, 0.5, 1, 2, 4 and 8 mg L(-1)) in combination with BAP (0, 0.25, 0.5, 1, 2, 4 and 8 mg L(-1)) were studied. Surface-sterilized corms were cut transversally into equal portions and the upper or lower parts were used separately as explants. All treatments were maintained in the darkness at 24 +/- 2 degrees C. After 70 days, the first globular embryos were observed and the number of embryos on each explant reached to its maximum 3 months after culture. Statistical analysis showed that there were significant differences between treatments regarding the number of embryos induced on each explant. The most effective treatment was 2.0 mg L(-1) 2,4-D + 1.0 mg L(-1) BAP for both types of explant (inducing 6.5 +/- 1.3 and 35.95 +/- 4.9 embryos on each explant for the upper and lower parts, respectively). The average percentages of explants showing embryogenic response were 33.3 and 93.3% for the upper and the lower part of corm tissue respectively in this treatment. Complementary studies are in progress to optimize maturation and germination stages of these somatic embryos. PMID:19090256

  2. Somatic embryogenesis in Eucalyptus globulus

    Microsoft Academic Search

    Greg Nugent; Stephen F. Chandler; Phil Whiteman; Trevor W. Stevenson

    2001-01-01

    Somatic embryos were obtained from 1% of cotyledon pieces and hypocotyls of mature embryos of Eucalyptus globulus Labill. cultured on media containing a high concentration of picloram or IBA. 2,4-D and other synthetic auxins did not yield somatic embryos or embryogenic callus. Somatic embryos arose indirectly via callus, being visible after four months, and directly, where little callus or adventitious

  3. SOMATIC EMBRYOGENESIS IN VENEZUELAN COCOA CULTIVARS

    Microsoft Academic Search

    Rosalía Velásquez Salazar; Yanet Sandrea; Carmen Betancourt; Jonás Mata; Félix García

    SUMMARY The traditional sexual and asexual methods of cocoa propagation have been widely used in Venezuela and worldwide, however, they have not been successful since plants with undesirable agronomic characteristics are produced. At present, plant regeneration via somatic embryogenesis provides an alternative method for clonally propagating cocoa. Therefore, a protocol was developed in order to use staminode, petal, anther and

  4. Somatic embryogenesis in Hedychium bousigonianum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An efficient primary somatic embryo (SE) and secondary somatic embryo (SSE) production system was developed for the ornamental ginger Hedychium bousigonianum Pierre ex Gagnepain. Addition of two ethylene inhibitors, salicylic acid (SA) and silver nitrate (AgNO3), to the culture media improved the sy...

  5. A new approach to direct somatic embryogenesis in Medicago.

    PubMed

    Denchev, P; Velcheva, M; Atanassov, A

    1991-09-01

    A highly efficient system for direct somatic embryogenesis is described. Leaf sections originating from young trifoliate leaves of Medicago falcata line 47/1-5 and Medicago sativa line No2/9R, directly produced embryos after cultivation in liquid B5IV induction medium. In comparison with indirect somatic embryogenesis the system omits the callus stage and thus allows shortening of the process of somatic embryogenesis in alfalfa by 35-40 days. It permits the avoidance of secondary changes occurring during the process of dedifferentiation. A modified B5/3H medium containing Polyethylene Glycol 6000 promoted embryo development from globular up to torpedo stage. It was clearly shown that 2.5% Polyethylene Glycol stimulated this process for both H. falcata 47/1-5 and M. sativa No 2/9R. Maturation of torpedo stage embryos was carried out on solidified or liquid abscisic acidcontaining medium. A 30?M abscisic acid concentration was optimal in allowing one embryo to yield one plant. Somatic embryo conversion to plants and plant regeneration was performed on Murashige and Skoog medium. Regenerated plants showed a normal morphology. PMID:24221669

  6. Potential link between biotic defense activation and recalcitrance to induction of somatic embryogenesis in shoot primordia from adult trees of white spruce (Picea glauca)

    PubMed Central

    2013-01-01

    Background Among the many commercial opportunities afforded by somatic embryogenesis (SE), it is the ability to clonally propagate individual plants with rare or elite traits that has some of the most significant implications. This is particularly true for many long-lived species, such as conifers, but whose long generation times pose substantive challenges, including increased recalcitrance for SE as plants age. Identification of a clonal line of somatic embryo-derived trees whose shoot primordia have remained responsive to SE induction for over a decade, provided a unique opportunity to examine the molecular aspects underpinning SE within shoot tissues of adult white spruce trees. Results Microarray analysis was used to conduct transcriptome-wide expression profiling of shoot explants taken from this responsive genotype following one week of SE induction, which when compared with that of a nonresponsive genotype, led to the identification of four of the most differentially expressed genes within each genotype. Using absolute qPCR to expand the analysis to three weeks of induction revealed that differential expression of all eight candidate genes was maintained to the end of the induction treatment, albeit to differing degrees. Most striking was that both the magnitude and duration of candidate gene expression within the nonresponsive genotype was indicative of an intense physiological response. Examining their putative identities further revealed that all four encoded for proteins with similarity to angiosperm proteins known to play prominent roles in biotic defense, and that their high-level induction over an extended period is consistent with activation of a biotic defense response. In contrast, the more temperate response within the responsive genotype, including induction of a conifer-specific dehydrin, is more consistent with elicitation of an adaptive stress response. Conclusions While additional evidence is required to definitively establish an association between SE responsiveness and a specific physiological response, these results suggest that biotic defense activation may be antagonistic, likely related to the massive transcriptional and metabolic reprogramming that it elicits. A major issue for future work will be to determine how and if suppressing biotic defense activation could be used to promote a physiological state more conducive to SE induction. PMID:23937238

  7. Somatic embryogenesis in plantain banana

    Microsoft Academic Search

    A. Grapin; J. Schwendiman; C. Teisson

    1996-01-01

    Summary  A cell suspension of French Sombre plantain banana (Musa spp. AAB genome) was initiated from callus obtained from young male flowers. Histological examination enabled us to describe and\\u000a follow the evolution of the suspension consisting of: embryogenic aggregates, proembryos, nodules, and isolated cells. It\\u000a demonstrated the unicellular origin of somatic embryos, either during maintenance of the suspension or after plating

  8. Studies on Somatic Embryogenesis in Sweetpotato

    NASA Technical Reports Server (NTRS)

    Bennett, J. Rasheed; Prakash, C. S.

    1997-01-01

    The purpose of this study was to improve the somatic embryo (SE) system for plant production of sweetpotato Ipomoea batatas L.(Lam)l. Explants isolated from SE-derived sweet potato plants were compared with control (non SE-derived) plants for their competency for SE production. Leaf explants were cultured on Murashige-Skoog (MS) medium with 2,4-dichlorophenoxy acetic acid (0.2 mg/L) and 6-benzylaminopurine (2.5 mg/L) for 2 weeks in darkness and transferred to MS medium with abscisic acid (2.5 Explants isolated from those plants developed through somatic embryo-genesis produced new somatic embryos rapidly and in higher frequency than those isolated from control plants. They also appeared to grow faster in tissue culture than the control plants. Current studies in the laboratory are examining whether plants derived from a cyclical embryogenesis system (five cycles) would have any further positive impact on the rapidity and frequency of somatic embryo development. More detailed studies using electron microscopy are expected to show the point of origin of the embryos and to allow determination of their quality throughout the cyclical process. This study may facilitate improved plant micropropagation, gene transfer and germplasm conservation in sweet potato.

  9. Direct somatic embryogenesis and plant regeneration from leaf cultures of ornamental species of Dianthus

    Microsoft Academic Search

    Aparna Pareek; S. L Kothari

    2003-01-01

    Protocol for direct somatic embryogenesis from leaf explants of economically important species of Dianthus, viz. D. caryophyllus, D. barbatus and D. chinensis has been developed. Murashige and Skoog’s (MS) liquid medium supplemented with 2,4-D (1mg\\/l) was used for direct induction of somatic embryogenesis without an intervening callus phase. Initially globular structures were observed after 21 days of culture of leaf

  10. Hemoglobins, programmed cell death and somatic embryogenesis.

    PubMed

    Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio

    2013-10-01

    Programmed cell death (PCD) is a universal process in all multicellular organisms. It is a critical component in a diverse number of processes ranging from growth and differentiation to response to stress. Somatic embryogenesis is one such process where PCD is significantly involved. Nitric oxide is increasingly being recognized as playing a significant role in regulating PCD in both mammalian and plant systems. Plant hemoglobins scavenge NO, and evidence is accumulating that events that modify NO levels in plants also affect hemoglobin expression. Here, we review the process of PCD, describing the involvement of NO and plant hemoglobins in the process. NO is an effector of cell death in both plants and vertebrates, triggering the cascade of events leading to targeted cell death that is a part of an organism's response to stress or to tissue differentiation and development. Expression of specific hemoglobins can alter this response in plants by scavenging the NO, thus, interrupting the death process. Somatic embryogenesis is used as a model system to demonstrate how cell-specific expression of different classes of hemoglobins can alter the embryogenic process, affecting hormone synthesis, cell metabolite levels and genes associated with PCD and embryogenic competence. We propose that plant hemoglobins influence somatic embryogenesis and PCD through cell-specific expression of a distinct plant hemoglobin. It is based on the premise that both embryogenic competence and PCD are strongly influenced by cellular NO levels. Increases in cellular NO levels result in elevated Zn(2+) and reactive-oxygen species associated with PCD, but they also result in decreased expression of MYC2, a transcription factor that is a negative effector of indoleacetic acid synthesis, a hormone that positively influences embryogenic competence. Cell-specific hemoglobin expression reduces NO levels as a result of NO scavenging, resulting in cell survival. PMID:23987809

  11. Somatic Embryogenesis: Identified Factors that Lead to Embryogenic Repression. A Case of Species of the Same Genus

    PubMed Central

    Nic-Can, Geovanny I.; Galaz-Ávalos, Rosa M.; De-la-Peña, Clelia; Alcazar-Magaña, Armando; Wrobel, Kazimierz; Loyola-Vargas, Víctor M.

    2015-01-01

    Somatic embryogenesis is a powerful biotechnological tool for the mass production of economically important cultivars. Due to the cellular totipotency of plants, somatic cells under appropriate conditions are able to develop a complete functional embryo. During the induction of somatic embryogenesis, there are different factors involved in the success or failure of the somatic embryogenesis response. Among these factors, the origin of the explant, the culture medium and the in vitro environmental conditions have been the most studied. However, the secretion of molecules into the media has not been fully addressed. We found that the somatic embryogenesis of Coffea canephora, a highly direct embryogenic species, is disrupted by the metabolites secreted from C. arabica, a poorly direct embryogenic species. These metabolites also affect DNA methylation. Our results show that the abundance of two major phenolic compounds, caffeine and chlorogenic acid, are responsible for inhibiting somatic embryogenesis in C. canephora. PMID:26038822

  12. Somatic Embryogenesis: Identified Factors that Lead to Embryogenic Repression. A Case of Species of the Same Genus.

    PubMed

    Nic-Can, Geovanny I; Galaz-Ávalos, Rosa M; De-la-Peña, Clelia; Alcazar-Magaña, Armando; Wrobel, Kazimierz; Loyola-Vargas, Víctor M

    2015-01-01

    Somatic embryogenesis is a powerful biotechnological tool for the mass production of economically important cultivars. Due to the cellular totipotency of plants, somatic cells under appropriate conditions are able to develop a complete functional embryo. During the induction of somatic embryogenesis, there are different factors involved in the success or failure of the somatic embryogenesis response. Among these factors, the origin of the explant, the culture medium and the in vitro environmental conditions have been the most studied. However, the secretion of molecules into the media has not been fully addressed. We found that the somatic embryogenesis of Coffea canephora, a highly direct embryogenic species, is disrupted by the metabolites secreted from C. arabica, a poorly direct embryogenic species. These metabolites also affect DNA methylation. Our results show that the abundance of two major phenolic compounds, caffeine and chlorogenic acid, are responsible for inhibiting somatic embryogenesis in C. canephora. PMID:26038822

  13. Direct somatic embryogenesis and synthetic seed production from Paulownia elongata

    Microsoft Academic Search

    Z. Ipekci; N. Gozukirmizi

    2003-01-01

    We have developed a reproducible system for efficient direct somatic embryogenesis from leaf and internodal explants of Paulownia elongata. The somatic embryos obtained were subsequently encapsulated as single embryos to produce synthetic seeds. Several plant growth regulators [6-benzylaminopurine, indole-3-acetic acid, a-naphthaleneacetic acid, kinetin and thidiazuron (TDZ)] alone or in combination were tested for their capacity to induce somatic embryogenesis. The

  14. Somatic Embryogenesis in Four Tree Legumes

    PubMed Central

    Das, Premananda

    2011-01-01

    Somatic embryogenesis was achieved in four leguminous tree species, that is, Acacia catechu, Acacia arabica, Hardwickia binata, and Dalbergia sissoo using immature zygotic embryos as explants on Murashige and Skoog (MS) medium supplemented with 0.25–1.0?mg/l Kn (kinetin) and 2.0–3.0?mg/l 2,4-D (2,4-dichlorophenoxyacetic acid) or NAA (1-napthaleneacetic acid) and 3% sucrose. MS medium containing 2.0?mg/l 2,4-D and 1.0–1.5?mg/l Kn was noted to be most effective in inducing friable embryogenic callus (FEC); the number of somatic embryos per culture varied in MS medium supplemented with 1.0–2.0?mg/l 2,4-D or NAA and 0.25–1.5?mg/l kinetin. The maximum number of somatic embryos was obtained in MS medium containing 1.5–2.0?mg/l 2,4-D or NAA and 1.0–1.5?mg/l kinetin; proliferation of embryogenic calli was enhanced in cultures having 1.0–2.0?mg/l 2,4-D, 1.0–1.5?mg/l kinetin, and 400–600?mg/l L-Proline. The somatic embryos in various shapes and sizes after the first subculture on MS medium supplemented with 0.1?mg/l IAA and 0.25?mg/l BA; developed shoots and rooted in 1/2 strength MS medium supplemented with 0.1?mg/l IBA or IAA. The somatic embryo-derived plantlets were transferred to the field after being hardened in the climate-controlled hardening chamber. PMID:21350667

  15. Role of exogenous reduced nitrogen and sucrose in rapid high frequency somatic embryogenesis in Medicago sativa

    Microsoft Academic Search

    Eltjo G. M. Meijer; Daniel C. W. Brown

    1987-01-01

    The effect of exogenously supplied reduced nitrogen and sucrose on high-frequency somatic embryogenesis in petiole-derived tissue cultures of a diploid and a tetraploid regenerable clone of Medicago sativa ssp. falcata was investigated. There was an absolute requirement for ammonium during embryo induction and differentiation, with 5mM being the optimum for induction and 10–20 mM the optimum for differentiation of somatic

  16. Papaver somniferum regeneration by somatic embryogenesis and shoot organogenesis

    Microsoft Academic Search

    M. Ove?ka; M. Bobák; A. Blehová; J. Krištín

    1997-01-01

    Secondary somatic embryogenesis and shoot organogenesis from primary somatic embryos of Papaver somniferum L. are described.\\u000a The embryos became malformed, the root meristem expressed dividing activity without position-dependent cell differentiation,\\u000a causing abnormal development or arrested growth of primary somatic embryos. The adventitious shoots regenerated from embryo\\u000a hypocotyl, but secondary somatic embryos had an epidermal origin close to the root meristem.

  17. Somatic embryogenesis in peanut: Influence of growth regulators and sugars

    Microsoft Academic Search

    Susan Eapen; Leela George

    1993-01-01

    Somatic embryogenesis and plant regeneration were induced from immature embryonal axes and immature cotyledons of peanut (Arachis hypogaea L. fastigata type cv JLM-1). Influence of different auxins, cytokinins and sugars on somatic embryogenesis from immature cotyledon explants was also investigated. Among the different auxins tested, 2,4-dichlorophenoxyacetic acid (2,4-d) was most effective, producing the highest frequency of responding cultures and highest

  18. Genetic variation in somatic embryogenesis of Rosa Hybrida L.

    E-print Network

    Burrell, Anna Mildred

    2004-09-30

    GENETIC VARIATION IN SOMATIC EMBRYOGENESIS OF ROSA HYBRIDA L. A Thesis by ANNA MILDRED BURRELL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2003 Major Subject: Horticulture GENETIC VARIATION IN SOMATIC EMBRYOGENESIS OF ROSA HYBRIDA L. A Thesis by ANNA MILDRED BURRELL Submitted to Texas A...

  19. Somatic embryogenesis and Agrobacterium-mediated transformation of Japanese apricot ( Prunus mume) using immature cotyledons

    Microsoft Academic Search

    Mei Gao; Makiko Kawabe; Tatsuya Tsukamoto; Hiromi Hanada; Ryutaro Tao

    2010-01-01

    This study describes a successful method of somatic embryogenesis and genetic transformation using immature cotyledons of Prunus mume. Immature cotyledons from four different developmental stages of eight different P. mume cultivars were used for the experiments to optimize somatic embryogenesis and genetic transformation protocols. Somatic embryogenesis was induced when the explants were cultured on somatic embryo inducing medium consisting of

  20. In vitro somatic embryogenesis and plant regeneration of cassava

    Microsoft Academic Search

    László Szabados; Rodrigo Hoyos; William Roca

    1987-01-01

    An efficient and reproducible plant regeneration system, initiated in somatic tissues, has been devised for cassava (Manihot esculenta Crantz). Somatic embryogenesis has been induced from shoot tips and immature leaves of in vitro shoot cultures of 15 cassava genotypes. Somatic embryos developed directly on the explants when cultured on a medium containing 4–16 mg\\/l 2,4-D. Differences were observed with respect

  1. Secondary somatic embryogenesis and plant regeneration in cassava

    Microsoft Academic Search

    James A. Stamp; Graham G. Henshaw

    1987-01-01

    Somatic embryos isolated from mature seed-derived cotyledon cultures of cassava (Mannihot esculenta Crantz) underwent direct secondary somatic embryogenesis or plant development under appropriate incubation conditions. Isolated somatic embryos were subjected to a two-stage culture procedure similar to that which induced their development on cotyledon explants. This involved incubation for 24–30 days on Murashige and Skoog basal medium supplemented with 2–8

  2. Somatic embryogenesis from immature peach palm inflorescence explants: towards development of an efficient protocol

    Microsoft Academic Search

    Douglas A. Steinmacher; Charles R. Clement; Miguel P. Guerra

    2007-01-01

    Various factors affect the induction of somatic embryogenesis in peach palm (Bactris gasipaes Kunth). Among these, both the type and level of auxins had the greatest influence on in vitro responses, although the genotype\\u000a and the developmental stage of the explants also influenced results. Younger inflorescences were more competent to respond\\u000a to SE induction than more mature inflorescences and the

  3. In vitro propagation of an endangered medicinal herb Chlorophytum borivilianum Sant. et Fernand. through somatic embryogenesis.

    PubMed

    Rizvi, Mohd Zahid; Kukreja, Arun Kumar; Bisht, Narendra Singh

    2010-07-01

    Tuberous roots of Chlorophytum borivilianum Sant. et Fernand. which are a source of steroidal saponins, possess immunomodulatory, adaptogenic, aphrodisiac, antipyretic, diuretic, hemostatic and anti-tumour properties. Poor seed setting and germination and slow growth in conventional vegetative propagation are major constraints in the large-scale cultivation of this commercially important medicinal plant. In the present study, a procedure for in vitro propagation of this endangered herb through somatic embryogenesis has been established. Seeds of Chlorophytum borivilianum were germinated on MS medium supplemented with 57.74 ?M gibberellic acid and hypocotyl portion from germinated seedling was used as explant for callus induction. Moderate to good callus induction was observed on MS medium containing 1.16 ?M kinetin and 1.13-2.26 ?M 2,4-dichlorophenoxyacetic acid. Regular subculturing of callus on kinetin (1.16 ?M) and 2,4-dichlorophenoxyacetic acid (1.13 ?M) supplemented medium induced somatic embryogenesis. In modified MS medium, 1.79 mM NH4NO3 and 10.72 mM KNO3 was optimal for somatic embryogenesis. 7.38 ?M 2-isopentenyladenine supplemented to modified MS medium, showed best response for somatic embryogenesis while proline (0.76 mM) as an amino acid supplement gave better response than glutamine. 30% germination of mature somatic embryos was achieved on MS medium supplemented with 15.54 ?M 6-benzylaminopurine. Multiplication of C. borivilianum through somatic embryogenesis may offer a better approach compared to organogenesis for developing scale-up technology employing bioreactors for its mass propagation. PMID:23572975

  4. Effect of hydrogen peroxide on somatic embryogenesis of Lycium barbarum L

    Microsoft Academic Search

    Cui Kairong; Xing Gengsheng; Liu Xinmin; Xing Gengmei; Wang Yafu

    1999-01-01

    The subject of this study is inducing somatic embryogenesis in the callus of Lyciumbarbarum L. and determining hydrogen peroxide in somatic embryogenesis. First of all, the activities of three antioxidant enzymes (SOD, peroxidase, catalase) in different stages of somatic embryogenesis were determined. The result showed that the activity of SOD gradually increased in the early days of differentiation culture and

  5. Uptake Rate of Tracer Elements by Lycium barbarum L. in Somatic Embryogenesis

    Microsoft Academic Search

    Li Shan; Shen Zhenghu; Qin Zhi; Wang Yafu

    2001-01-01

    The subject of this study was inducing somatic embryogenesis in the callus of Lycium barbarum L., The uptake rate of several metal ions in somatic embryogenesis was investigated by multitracer techniques. It was found that some metal ions changed the somatic embryogenesis dynamically. The uptake rates of metal ions were different from each other and exert mutual effect, mutual influence

  6. Secondary somatic embryogenesis of carnation ( Dianthus caryophyllus L.)

    Microsoft Academic Search

    Omid Karami; Ali Deljou; Gona Karimi Kordestani

    2008-01-01

    This is the first report describing culture conditions necessary to induce secondary embryogenesis in two carnation cultivars,\\u000a Nelson and Spirit. In the first step, embryogenic calli were induced on petal explants followed by development of primary\\u000a somatic embryos from the calli. In the second stage, secondary somatic embryos were obtained when precotyledonary and cotyledonary\\u000a primary embryos were isolated and transferred

  7. Changes in protein profiles associated with somatic embryogenesis in peanut

    Microsoft Academic Search

    A. Roja Rani; V. D. Reddy; P. Prakash Babu; G. Padmaja

    2005-01-01

    The somatic embryogenesis potential of zygotic embryo axes of peanut (Arachis hypogaea L. cv. DRG-12) at different stages of development was evaluated by culturing on MS medium with 18.1 ?M 2,4-dichlorophenoxyacetic acid (2,4-D). A 100 % frequency with 18.3 somatic embryos per explant was observed from 4 mm long immature zygotic embryo axes collected 31 – 40 d after pollination.

  8. Yield performance of cacao propagated by somatic embryogenesis and grafting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve cacao (Theobroma cacao) clones propagated by grafting and somatic embryogenesis and grown on an Ultisol soil were evaluated for five years under intensive management at Corozal, Puerto Rico. Preliminary data showed no significant differences between propagation methods for yield of dry beans ...

  9. Assessment of somatic embryogenesis potency in Indian soybean [Glycine max (L.) Merr.] cultivars.

    PubMed

    Mariashibu, Thankaraj Salammal; Subramanyam, Kondeti; Arun, Muthukrishnan; Theboral, Jeevaraj; Rajesh, Manoharan; Rengan, Sampath Kasthuri; Chakravarthy, Rajan; Manickavasagam, Markandan; Ganapathi, Andy

    2013-10-01

    Majority of the Indian soybean cultivars are recalcitrant to tissue culture regeneration. The present communication reports the development of somatic embryogenesis in a liquid culture medium from immature cotyledons of G. max. Following induction with 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthalene acetic acid (NAA), the number of somatic embryos and percentage of explants that responded were higher with 45.24 microM 2,4-D. The proliferation of somatic embryos for three successive cycles was achieved in 22.62 microM 2,4-D. Histodifferentiation of somatic embryos under NAA (10.74 microM) indicated that better embryo development and maturation was achieved without any growth regulator. The amino acids such as L-glutamine favoured the somatic embryo induction and histodifferentiation at 20 and 30 mM respectively, where as L-asparagine at 10 mM concentration enhanced the somatic embryo proliferation. In addition, somatic embryos that were desiccated (air-drying method) for 5 days showed better germination (40.88%). The Indian soybean cultivars also showed strict genotypic influence and cv. Pusa 16 was emerged as a best responding cultivar for somatic embryo induction with 74.42% of response. PMID:24266110

  10. Somatic embryogenesis and regeneration of Cenchrus ciliaris genotypes from immature inflorescence explants

    Microsoft Academic Search

    C. B. Yadav; P. Jha; C. Mahalakshmi; V. Anjaiah; V. Bhat

    2009-01-01

    An efficient, highly reproducible system for plant regeneration via somatic embryogenesis was developed for Cenchrus ciliaris genotypes IG-3108 and IG-74. Explants such as seeds, shoot tip segments and immature inflorescences were cultured on Murashige\\u000a and Skoog (MS) medium supplemented with 2.0–5.0 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg dm?3 N6-benzyladenine (BA) for induction of callus. Callus could be successfully

  11. High frequency somatic embryogenesis and plant regeneration in callus cultures of Astragalus adsurgens Pall

    Microsoft Academic Search

    Jian-Ping Luo; Jing-Fen Jia; Yue-Hua Gu; Jing Liu

    1999-01-01

    Efficient plant regeneration through somatic embryogenesis was achieved in Astragalus adsurgens. Embryogenic callus was induced from hypocotyl, not root or cotyledon explants, and the maximum induction frequency (62%) was obtained on Murashige and Skoog (1962) basal medium (MS) containing 2.0 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg\\/l N6-benzylaminopurine (BA). Transfer of embryogenic calli to MS medium with 1–2 mg\\/l BA

  12. Somatic embryogenesis and plant regeneration from pistil transverse thin cell layers of lemon (Citrus limon)

    Microsoft Academic Search

    Maurizio Sajeva; Angela Carra; Fabio de Pasquale; Francesco Carimi

    2008-01-01

    Callus induction, somatic embryogenesis and plant regeneration were obtained in Citrus limon (L.) Burm. (cv. Femminello) from cultures of pistil transverse thin cell layer explants [(t)TCLs]. Explants were cultured on two different media, based on Murashige and Skoog salts and vitamins, supplemented with 500 mg l malt extract (MSI), or 500 mg l malt extract and 13.3 ?M 6-benzylaminopurine (MSII). Sucrose (146

  13. The analysis of differential gene expression in early somatic embryogenesis on Lycium barbarum

    Microsoft Academic Search

    Cui Kairong; Xing Gengsheng; Qin Lin; Liu Xinmin; Wang Yafu

    1999-01-01

    Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somatic embryogenesis. Somatic\\u000a \\u000a embryogenesis of Lycium barbarum L. is controlled artificially by regulating 2,4-D concentration. The total RNA that was isolated from calluses, embryonic\\u000a calluses and early somatic embryos was used for analyzing differential genes expression. We obtained three cDNAs from early\\u000a somatic embryogenesis which were

  14. Somatic embryogenesis and plant regeneration of neem (Azadirachta indica A. Juss.)

    Microsoft Academic Search

    B. N. S. Murthy; Praveen K. Saxena

    1998-01-01

    Somatic embryos were initiated with mature seeds of neem (Azadirachta indica A. Juss.) when cultured on Murashige and Skoog's medium supplemented with thidiazuron (TDZ). Regeneration occurred via somatic\\u000a embryogenesis: direct embryo formation and through an intermediary callus phase. TDZ was very effective and induced somatic\\u000a embryogenesis across a wide range of concentrations (1–50 µm). However, somatic embryogenesis was accompanied by

  15. High efficiency secondary somatic embryogenesis in Hovenia dulcis Thunb. through solid and liquid cultures.

    PubMed

    Yang, Jingli; Wu, Songquan; Li, Chenghao

    2013-01-01

    Embryogenic callus was obtained from mature seed explants on medium supplemented with 2,4-dichlorophenoxyacetic acid. Primary somatic embryos (SEs) can only develop into abnormal plants. Well-developed SEs could be obtained through secondary somatic embryogenesis both in solid and liquid cultures. Temperature strongly affected induction frequency of secondary embryogenesis. Relatively high temperature (30°C) and germinated SEs explants were effective for induction of secondary somatic embryos, and low temperature (20°C) was more suitable for further embryo development, plantlet conversion, and transplant survival. Somatic embryos formed on agar medium had larger cotyledons than those of embryos formed in liquid medium. Supplementing 0.1?mg?L(-1) 6-benzyladenine (BA) was effective for plant conversion; the rate of plant conversion was 43.3% in somatic embryos from solid culture and 36.5% in embryos from liquid culture. In vitro plants were successfully acclimatized in the greenhouse. The protocol established in this study will be helpful for large-scale vegetative propagation of this medicinal tree. PMID:23818829

  16. Somatic embryogenesis from Sorghum bicolor leaves

    Microsoft Academic Search

    Wolfgang Wernicke; Richard Brettell

    1980-01-01

    Plant regeneration from totipotent cultured cells or protoplasts is a prerequisite for the often proposed genetic modification of plants through somatic cell genetics, and has been achieved in many species. The cereals (and the rest of the Gramineae) have, however, proved to be extremely unresponsive to in vitro culture techniques1. The most convenient source of plant protoplasts is the leaf

  17. [Somatic embryogenesis in in vitro culture of three larch species].

    PubMed

    Tret'iakova, I N; Barsukova, A V

    2012-01-01

    Embryogenic callus formation in different larch species from Siberia (Larix sibirica, L. gmelinii, and L. sukaczewii) was carried out on MSGm medium supplemented with growth regulators (2.4-D and BAP) and followed one and the same scheme: elongation of somatic cells and their asymmetric division with formation of initial and tube cells. The cells of embryo initial underwent sequential divisions and formed embryonic globules which caused the formation of somatic embryos. Somatic embryos became mature and germinated by addition of ABA and PEG into the medium. Long-term proliferating cell lines and regenerant plants were obtained in Sukachev larch and its hybrid with Siberian larch. The success of somatic embryogenesis depended on the genotype of the donor tree. PMID:23401960

  18. Role of trace elements in somatic embryogenesis A PIXE study

    NASA Astrophysics Data System (ADS)

    Saha, P.; Raychaudhuri, S.; Mishra, D.; Chakraborty, A.; Sudarshan, M.

    2008-03-01

    Proton induced X-ray emission was used to study the trace elemental profiles of embryogenic and non-embryogenic callus of an important cash crop of India - Plantago ovata. Somatic embryogenesis, a well-known process for plant regeneration and crop improvement is modulated by various factors such as ionizing radiation and micro nutrients in the growth media. The present work reports the trace element variation in normal and irradiated callus tissue of P. ovata. Embryogenic and non-embryogenic callus tissues were exposed to gamma rays from a 60Co gamma source. The absorbed dose ranged from 10 to 100 Gy. Subsequent experiments showed significant dose dependent alterations in K, Ca, Mn, Fe, Ni, Cu, Zn, Br, Sr in both the embryogenic and non-embryogenic callus. The precise involvement of these elements has been discussed in light of somatic embryogenesis of the selected medicinal plant.

  19. Somatic embryogenesis in the medicinal legume Desmodium motorium (Houtt.) Merr

    Microsoft Academic Search

    B. Chitra Devi; V. Narmathabai

    2011-01-01

    An efficient protocol was established for regeneration of Desmodium motorium via somatic embryogenesis. Embryogenic calli were induced from cotyledon segments (6 mm, 16 days old) lacking embryo axis,\\u000a excised from seedlings grown in vitro on Murashige and Skoog (MS) medium supplemented with indole-3-acetic acid (IAA) (2.9 ?M)\\u000a in combination with 6-benzyladenine (BA) (4.44 and 8.88 ?M). Differentiation of embryogenic calli into globular and heart-shaped\\u000a somatic

  20. Somatic embryogenesis and in vitro flowering in Brassica nigra

    Microsoft Academic Search

    U. J. Mehta; S. Hazra; A. F. Mascarenhas

    1993-01-01

    Summary  This report describes a protocol for regeneration ofBrassica nigra in vitro from unorganized callus to a highly differentiated stage of flowering. Callus is initiated from seedling hypocotyl,\\u000a and root explants and plantlets are obtained via somatic embryogenesis. Shoot cultures can be established from these plantlets.\\u000a These shoots can either be induced to flower in vitro or rooted to produce plants

  1. Histology of somatic embryogenesis from floral tissues cocoa

    Microsoft Academic Search

    L. Alemanno; M. Berthouly; N. Michaux-Ferrière

    1996-01-01

    Somatic embryogenesis fromTheobroma cacao L. flower buds, as previously reported on five Forastero hybrid genotypes, was tested on several other genotypes, belonging to the three cocoa-tree groups: Forastero, Trinitario and Criollo. The results gave evidence of genotypic efficiencies. Explants were cultivated under two successive conditions: callogenesis and expression media. The morphological and histological responses were different for embryogenic or non-embryogenic

  2. Effect of Salicylic Acid on Somatic Embryogenesis and Plant Regeneration in Hedychium bousigonianum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to induce somatic embryogenesis in Hedychium bousigonianum Pierre ex Gagnepain and assess the influence of salicylic acid (S) on somatic embryogenesis. Somatic embryos and subsequently regenerated plants were successfully obtained 30 days after transfer of embryogenic...

  3. Induction, maturation and germination of holm oak ( Quercus ilex L.) somatic embryos

    Microsoft Academic Search

    P. V. Mauri; J. A. Manzanera

    2003-01-01

    Somatic embryo induction from immature zygotic embryos followed by embryo development and maturation has been achieved in holm oak (Quercus ilex L.). Different types of explant have been assayed for the induction of somatic embryogenesis. Only immature zygotic embryos, collected in August, were successfully induced. Best results were obtained in Gamborg et al. (1968) medium supplemented with 10 µM BAP

  4. Somatic embryogenesis of a wild passion fruit species Passiflora cincinnata Masters: histocytological and histochemical evidences.

    PubMed

    Rocha, Diego Ismael; Vieira, Lorena Melo; Tanaka, Francisco André Ossamu; da Silva, Luzimar Campos; Otoni, Wagner Campos

    2012-07-01

    The characterization of cellular changes that occur during somatic embryogenesis is essential for understanding the factors involved in the transition of somatic cells into embryogenically competent cells and determination of cells and/or tissues involved. The present study describes the anatomical and ultrastructural events that lead to the formation of somatic embryos in the model system of the wild passion fruit (Passiflora cincinnata). Mature zygotic embryos were inoculated in Murashige and Skoog induction media supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzyladenine. Zygotic embryo explants at different development stages were collected and processed by conventional methods for studies using light, scanning, and transmission electron microscopy (TEM). Histochemical tests were used to examine the mobilization of reserves. The differentiation of the somatic embryos began in the abaxial side of the cotyledon region. Protuberances were formed from the meristematic proliferation of the epidermal and mesophyll cells. These cells had large nuclei, dense cytoplasm with a predominance of mitochondria, and a few reserve compounds. The protuberances extended throughout the abaxial surface of the cotyledons. The ongoing differentiation of peripheral cells of these structures led to the formation of proembryogenic zones, which, in turn, dedifferentiated into somatic embryos of multicellular origin. In the initial stages of embryogenesis, the epidermal and mesophyll cells showed starch grains and less lipids and protein reserves than the starting explant. These results provide detailed information on anatomical and ultrastructural changes involved in the acquisition of embryogenic competence and embryo differentiation that has been lacking so far in Passiflora. PMID:21927886

  5. In vitro propagation of ash (Fraxinus excelsior L.) by somatic embryogenesis.

    PubMed

    Capuana, Maurizio

    2013-01-01

    Induction of somatic embryogenesis is described in common ash (Fraxinus excelsior L.). Embryogenic tissues are obtained from immature zygotic embryos and cultured on a modified Murashige and Skoog (MS) medium containing 8.8 ?M 2,4-dichlorophenoxyacetic acid and 4.4 ?M benzyl-adenine. Embryogenic tissue is subcultured and multiplied on medium supplemented with reduced concentration of plant growth hormones. Somatic embryos develop and mature by transfer to hormone-free medium and subsequent culture on medium containing low amount of benzyladenine. Somatic embryo germination and conversion are enhanced by cold storage at 4°C and successive transfer onto Woody Plant Medium (WPM). Fully developed plantlets are then transferred to pots and acclimatized in the greenhouse equipped with a mist system. PMID:23179701

  6. Somatic embryogenesis from flower explants of cocoa (Theobroma cacao L.).

    PubMed

    Silva, J J; Debergh, P

    2001-01-01

    Two types of flower explants, staminoides and petals, were used for in vitro induction of somatic embryos in cocoa. After 14 days in culture, we observed globular structures and callus formation on both types of explants. However, the better results were obtained on staminoides: 98.3% formed callus and 86.2% somatic embryos on Murashige and Skoog (1962) medium supplemented with sucrose, coconut water, 2,4-D, kinetin and agar. PMID:15952427

  7. G.S. Pullman and S. JohnsonSomatic embryogenesis initiation of loblolly pine Original article

    E-print Network

    Boyer, Edmond

    G.S. Pullman and S. JohnsonSomatic embryogenesis initiation of loblolly pine Original article Somatic embryogenesis in loblolly pine (Pinus taeda L.): improving culture initiation rates Gerald S, USA (Received 5 July 2001; accepted 5 February 2002) Abstract ­ Loblolly pine (Pinus taeda L.) is one

  8. Localization and Identification of Phenolic Compounds in Theobroma cacao L. Somatic Embryogenesis

    Microsoft Academic Search

    L. A LEMANNO; T. R AMOS; A. G ARGADENEC; C. A NDARY; N. F ERRIERE

    2003-01-01

    Cocoa breeders and growers continue to face the problem of high heterogeneity between individuals derived from one progeny. Vegetative propagation by somatic embryogenesis could be a way to increase genetic gains in the field. Somatic embryogenesis in cocoa is difficult and this species is considered as recalcitrant. This study was conducted to investigate the phenolic composition of cocoa flowers (the

  9. Efficient and rapid plant regeneration of oil palm zygotic embryos cv. ‘Tenera’ through somatic embryogenesis

    Microsoft Academic Search

    Mya Thuzar; Apichart Vanavichit; Somvong Tragoonrung; Chatchawan Jantasuriyarat

    2011-01-01

    An efficient and rapid plant regeneration system through somatic embryogenesis was developed using 13-week-old zygotic embryos\\u000a of oil palm (Elaeis guineensis Jacq.) cv. ‘Tenera’. Zygotic embryos were cultured on MS and N6 media supplemented with 2.0 mg L?1 picloram, 2,4-D and dicamba. The highest embryogenic callus formation (32%) was observed on N6 medium with 2,4-D after 3 month\\u000a culture on callus induction

  10. Study of elemental variations during somatic embryogenesis in sugarcane using photon induced X-ray probe

    NASA Astrophysics Data System (ADS)

    Desai, N. S.; Joseph, D.; Suprasanna, P.; Bapat, V. A.

    2006-11-01

    Energy-dispersive X-ray fluorescence technique (EDXRF) has been extensively used to characterize trace element profiles during plant growth under stress and development. In this study, elemental accumulation was analyzed using EDXRF technique during somatic embryogenesis, from de-differentiated callus (S1) to proembryogenic callus (S2), embryogenic callus with developing embryos (S3) and embryo converted plantlets (S4, S5). There was much variation in Mg, K, Ca, Mn, Fe, Cu and Zn. Higher Mg (4.6%) K (1068 ppm) and Fe accumulation was observed in proembryogenic callus (S2) stage compared to other stages suggesting specific elemental accumulation in embryogenic callus. The results suggest that the information on the accumulation of elements during developmental stages in vitro could be useful for formulating a media for induction of high frequency of embryogenesis in sugarcane.

  11. Changes of gentiopicroside synthesis during somatic embryogenesis in Gentiana macrophylla.

    PubMed

    Chen, Li-Yu; Chen, Qian-Liang; Xu, Dan; Hao, Jian-Guo; Schläppi, Michael; Xu, Zi-Qin

    2009-12-01

    IN VITRO plant regeneration of Gentiana macrophylla Pall. and determination of gentiopicroside content during somatic embryogenesis are described in the present work. The highest percentage of embryogenic callus formation was observed in Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg/L 6-benzylaminopurine (BA). Calli were subcultured on MS medium containing 1.0 mg/L 2,4-D, 1.0 mg/L BA and 500 mg/L lactalbumin hydrolysate (LH) at intervals of 25 days. A higher frequency of somatic embryo maturation was achieved on MS medium containing B5 vitamins (MB) supplemented with different concentrations of 1-naphthaleneacetic acid (NAA) and BA than with a combination of NAA and kinetin (KT). Addition of AgNO(3) improved maturation of somatic embryos while thidiazuron (TDZ) promoted vitrification. The gentiopicroside contents of embryogenic calli and globular-, heart-, torpedo-, and cotyledon-shaped embryoids were determined by high-performance liquid chromatography (HPLC). Gentiopicroside was not detectable in embryogenic calli, but in all types of somatic embryos. The highest gentiopicroside content was observed in cotyledon-shaped embryoids, reaching more than 12 mg/g dry weight. PMID:19548190

  12. Label-Free Quantitative Proteomics of Embryogenic and Non-Embryogenic Callus during Sugarcane Somatic Embryogenesis.

    PubMed

    Heringer, Angelo Schuabb; Barroso, Tatiana; Macedo, Amanda Ferreira; Santa-Catarina, Claudete; Souza, Gustavo Henrique Martins Ferreira; Floh, Eny Iochevet Segal; de Souza-Filho, Gonçalo Apolinário; Silveira, Vanildo

    2015-01-01

    The development of somatic cells in to embryogenic cells occurs in several stages and ends in somatic embryo formation, though most of these biochemical and molecular changes have yet to be elucidated. Somatic embryogenesis coupled with genetic transformation could be a biotechnological tool to improve potential crop yields potential in sugarcane cultivars. The objective of this study was to observe somatic embryo development and to identify differentially expressed proteins in embryogenic (E) and non-embryogenic (NE) callus during maturation treatment. E and NE callus were cultured on maturation culture medium supplemented with different concentrations (0.0, 0.75, 1.5 and 2.0 g L-1) of activated charcoal (AC). Somatic embryo formation and differential protein expression were evaluated at days 0 and 21 using shotgun proteomic analyses. Treatment with 1.5 g L-1 AC resulted in higher somatic embryo maturation rates (158 somatic embryos in 14 days) in E callus but has no effect in NE callus. A total of 752 co-expressed proteins were identified through the SUCEST (The Sugarcane EST Project), including many housekeeping proteins. E callus showed 65 exclusive proteins on day 0, including dehydrogenase, desiccation-related protein, callose synthase 1 and nitric oxide synthase. After 21 days on maturation treatment, 14 exclusive proteins were identified in E callus, including catalase and secreted protein. NE callus showed 23 exclusive proteins on day 0 and 10 exclusive proteins after 21 days on maturation treatment, including many proteins related to protein degradation. The induction of maturation leads to somatic embryo development, which likely depends on the expression of specific proteins throughout the process, as seen in E callus under maturation treatment. On the other hand, some exclusive proteins can also specifically prevent of somatic embryos development, as seen in the NE callus. PMID:26035435

  13. Label-Free Quantitative Proteomics of Embryogenic and Non-Embryogenic Callus during Sugarcane Somatic Embryogenesis

    PubMed Central

    Heringer, Angelo Schuabb; Barroso, Tatiana; Macedo, Amanda Ferreira; Santa-Catarina, Claudete; Souza, Gustavo Henrique Martins Ferreira; Floh, Eny Iochevet Segal; de Souza-Filho, Gonçalo Apolinário; Silveira, Vanildo

    2015-01-01

    The development of somatic cells in to embryogenic cells occurs in several stages and ends in somatic embryo formation, though most of these biochemical and molecular changes have yet to be elucidated. Somatic embryogenesis coupled with genetic transformation could be a biotechnological tool to improve potential crop yields potential in sugarcane cultivars. The objective of this study was to observe somatic embryo development and to identify differentially expressed proteins in embryogenic (E) and non-embryogenic (NE) callus during maturation treatment. E and NE callus were cultured on maturation culture medium supplemented with different concentrations (0.0, 0.75, 1.5 and 2.0 g L-1) of activated charcoal (AC). Somatic embryo formation and differential protein expression were evaluated at days 0 and 21 using shotgun proteomic analyses. Treatment with 1.5 g L-1 AC resulted in higher somatic embryo maturation rates (158 somatic embryos in 14 days) in E callus but has no effect in NE callus. A total of 752 co-expressed proteins were identified through the SUCEST (The Sugarcane EST Project), including many housekeeping proteins. E callus showed 65 exclusive proteins on day 0, including dehydrogenase, desiccation-related protein, callose synthase 1 and nitric oxide synthase. After 21 days on maturation treatment, 14 exclusive proteins were identified in E callus, including catalase and secreted protein. NE callus showed 23 exclusive proteins on day 0 and 10 exclusive proteins after 21 days on maturation treatment, including many proteins related to protein degradation. The induction of maturation leads to somatic embryo development, which likely depends on the expression of specific proteins throughout the process, as seen in E callus under maturation treatment. On the other hand, some exclusive proteins can also specifically prevent of somatic embryos development, as seen in the NE callus. PMID:26035435

  14. Direct somatic embryogenesis, plant regeneration and in vitro flowering in rapid-cycling Brassica napus

    Microsoft Academic Search

    W. L. Koh; C. S. Loh

    2000-01-01

    A simple method to induce somatic embryogenesis from seeds of rapid-cycling Brassica napus is described. Seedlings cultured on Murashige and Skoog (MS) basal medium produced somatic embryos directly on hypocotyls\\u000a and cotyledons after 2 to 3 subcultures onto the same medium. A low pH of the medium (3.5–5) was more conducive to somatic\\u000a embryogenesis than a higher pH (6 and

  15. Isolation and Characterization of Genes Associated to Cotton Somatic Embryogenesis by Suppression Subtractive Hybridization and Macroarray

    Microsoft Academic Search

    Fanchang Zeng; Xianlong Zhang; Longfu Zhu; Lili Tu; Xiaoping Guo; Yichun Nie

    2006-01-01

    Somatic embryogenesis (SE) is the developmental reprogramming of somatic cells toward the embryogenesis pathway and is a notable\\u000a illustration of cell totipotency. To identify genes involved in SE, subtractive polymerase chain reaction (PCR) was performed\\u000a to generate transcripts highly enriched for SE-related genes, using cDNA prepared from a mixture of embryogenic callus and\\u000a preglobular somatic embryos, as the tester, and

  16. In vitro somatic embryogenesis and plantlet regeneration from immature male inflorescence of adult dura and tenera palms of Elaeis guineensis (Jacq.).

    PubMed

    Jayanthi, Madhavan; Susanthi, Bollarapu; Murali Mohan, Nandiganti; Mandal, Pranab Kumar

    2015-01-01

    We report here a method for plant regeneration through somatic embryogenesis from explants collected from immature male inflorescence of adult oil palm cultivated in India. Callus induction was successful from tissues of immature male inflorescence collected from both dura and tenera varieties of oil palm. A modified Y3 (Eeuwens) media supplemented with several additives and activated charcoal (3%) were used for the experiments. Out of four different auxin treatments, 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid (picloram) produced maximum callus induction (82%) and it was not significantly different from 2,4-dichlorophenoxyacetic acid (2,4-D) and a combination of 2,4-D + picloram. The callus induction obtained with auxin ?-naphthalene acetic acid was only 54% and it was significantly low as compared to the other treatments. Highest embryogenesis was obtained with a combination of 2,4-D + picloram (4.9%) followed by picloram (3.4%). Genotypic variation in response to the same auxins was observed both for callus induction and embryogenesis. Callus induction and embryogenesis ranged from 42 to 72% and 6.8 to 9.35%, respectively in tenera. The formation of embryogenic calli was marked by the appearance of white to yellowish globular or nodular structures which subsequently formed clear somatic embryos. Somatic embryogenesis was asynchronous and at one time we could find different stages of embryogenesis like the globular, torpedo and the cotyledonary stages. The somatic embryos when exposed to light in the same basal media along with 6-benzyladenine (18 µM), abscisic acid (3.78 µM) and gibberellic acid (5.78 µM) regenerated into plantlets. To the best of our knowledge this is the first report o f callus induction and somatic embryogenesis from immature male inflorescence of oil palm. PMID:26085976

  17. N-acetylglucosamine and glucosamine-containing arabinogalactan proteins control somatic embryogenesis

    Microsoft Academic Search

    Hengel van A. J; Zewdie Tadesse; Peter Immerzeel; Henk Schols; Ab van Kammen; Vries de S. C

    2001-01-01

    In plants, complete embryos can develop not only from the zygote, but also from somatic cells in tissue culture. How somatic cells undergo the change in fate to become embryogenic is largely unknown. Proteins, secreted into the culture medium such as endochitinases and arabinogalactan proteins (AGPs) are required for somatic embryogenesis. Here we show that carrot (Daucus carota) AGPs can

  18. 2,4,5-Trichlorophenoxyacetic acid promotes somatic embryogenesis in the rose cultivar ‘Livin’ Easy’ ( Rosa sp.)

    Microsoft Academic Search

    Tammy Estabrooks; Robin Browne; Zhongmin Dong

    2007-01-01

    Somatic embryogenesis (SE) offers vast potential for the clonal propagation of high-value roses. However, some recalcitrant\\u000a cultivars unresponsive to commonly employed SE-inducing agents and low induction rates currently hinder the commercialization\\u000a of SE technology in rose. Rose SE technology requires improvement before it can be implemented as a production system on a\\u000a commercial scale. In the present work, we assessed

  19. High-efficiency transformation of Lycium barbarum mediated by Agrobacterium tumefaciens and transgenic plant regeneration via somatic embryogenesis

    Microsoft Academic Search

    Z. Hu; J. Yang; G. Guo; G. Zheng

    2002-01-01

    We have developed a reliable and high-frequency system of transformation and regeneration via somatic embryogenesis (SE) of Lycium barbarum. Leaf segments were co-cultivated with Agrobacterium tumefaciens EHA101 (pIG121Hm) carrying the neomycin phosphotransferase II gene as a selectable marker and an intron-#-glucuronidase (GUS) gene as a reporter marker. On the medium for callus-induction, which contained 50 mg l-1 kanamycin (Km), approximately

  20. Initiation of somatic embryogenesis from immature zygotic embryos of oocarpa pine (Pinus oocarpa Schiede ex Schlectendal).

    PubMed

    Lara-Chavez, Alejandra; Flinn, Barry S; Egertsdotter, Ulrika

    2011-05-01

    The focus of the current project was to establish somatic embryogenesis protocols for the tropical pine species Pinus oocarpa using immature zygotic embryos (ZEs) as explants. Somatic embryogenesis is best supported by mimicking natural seed-embryo developmental conditions, through a tissue culture medium formulation based on the mineral content of the seed nutritive tissue [megagametophyte (MG)]. A novel culture medium (P. oocarpa medium, PO) was tested in combination with different plant growth regulator (PGR) concentrations and compared with standard Pinus taeda media for the initiation of somatic embryogenesis from immature ZEs of P. oocarpa. Immature MGs containing immature ZEs of two mother trees were used with 12 and 8% extrusion rates for mother tree genotypes 3 and 5, respectively. In both mother trees the percentage capture was 2%. Multiplication of two captured cell lines (T5C2S01 and T5C1S12) was improved by lowering the concentrations of PGRs to 2.5 µM each 2,4-dichlorophenoxyacetic acid and abscisic acid (ABA) plus 1.0 µM each 6-benzylaminopurine and kinetin. Mature somatic embryos formed on 40 µM ABA, 6% (w/v) maltose, 12% (w/v) PEG 8000 and 0.6% (w/v) Phytagel. While PO medium appeared suboptimal for somatic embryo induction, it did exhibit potential for enhanced culture proliferation and subsequent improved maturation with cell line T5C2S01, where microscopic analysis revealed better embryo morphology on PO medium than on 1250 medium. However, this enhancement was not observed with cell line T5C1S12. Germination was preceded by partial desiccation for a period of 2-3 weeks before transferring the embryos to germination medium. Germination was observed after 7 days under low light, and apical primordia slowly expanded after transfer to ex vitro conditions. To our knowledge, this is the first report on the production of somatic seedlings in P. oocarpa. PMID:21636694

  1. An efficient in vitro system for somatic embryogenesis and podophyllotoxin production in Podophyllum hexandrum Royle.

    PubMed

    Rajesh, Manoharan; Sivanandhan, Ganeshan; Jeyaraj, Murugaraj; Chackravarthy, Rajan; Manickavasagam, Markandan; Selvaraj, N; Ganapathi, Andy

    2014-09-01

    Podophyllum hexandrum Royle known as Indian mayapple is an important medicinal plant found only in higher altitudes (2,700 to 4,200 m) of the Himalayas. The highly valued anticancer drug Podophyllotoxin is obtained from the roots of this plant. Due to over exploitation, this endemic plant species is on the verge of extinction. In vitro culture for efficient regeneration and the production of podophyllotoxin is an important research priority for this plant. Hence, in the present study, an efficient plant regeneration system for mass multiplication through somatic embryogenesis was developed. We have screened P. hexandrum seeds collected from three different regions in the Himalayas to find their regenerative potentials. These variants showed variation in germination percentage as well as somatic embryogenic frequency. The seeds collected from the Milam area of Pithoragarh district showed better germination response (99.3%) on Murashige and Skoog (MS) medium fortified with Gibberellic acid (GA3 [5 mg/l]) and higher direct somatic embryogenic frequency (89.6%). Maximum production of embryogenic callus (1.2 g fresh weight [FW]) was obtained when cotyledons containing the direct somatic embryo clusters were cultured in MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D [1.5 mg/l]) after 4 week of culture in complete darkness. In the present investigation, somatic embryogenesis was accomplished either by direct organogenesis or callus mediated pathways. The latter method resulted in a higher frequency of somatic embryo induction in hormone-free MS medium yielding 47.7 embryos/50 mg of embryogenic callus and subsequent germination in MS medium supplemented with GA3 (5 mg/l). Seventy-nine percent of embryos attained complete maturity and germinated into normal plants with well-developed roots. Systematic histological analysis revealed the origin of somatic embryo and their ontogenesis. The higher level of podophyllotoxin (1.8 mg/g dry weight [DW]) was recorded in germinated somatic embryos when compared to field grown plants. The present system can be widely used for mass propagation, transgenic recovery, and podophyllotoxin production for commercial utilization. PMID:24633328

  2. High frequency regeneration via direct somatic embryogenesis and efficient Agrobacterium-mediated genetic transformation of tobacco.

    PubMed

    Pathi, Krishna Mohan; Tula, Suresh; Tuteja, Narendra

    2013-06-01

    A direct somatic embryogenesis protocol was developed for four cultivars of Nicotiana species, by using leaf disc as an explant. Direct somatic embryogenesis of Nicotiana by using BAP and IAA has not been investigated so far. This method does not require formation of callus tissues which leads to somaclonal variations. The frequency of somatic embryogenesis was strongly influenced by the plant growth hormones. The somatic embryos developing directly from explant tissue were noticed after 6 d of culture. Somatic embryogenesis of a high frequency (87-96%) was observed in cultures of the all four genotypes (Nicotiana tabacum, N. benthamiyana, N. xanthi, N. t cv petihavana). The results showed that the best medium for direct somatic embryogenesis was MS supplemented with 2.5 mg/l, 0.2 mg/l IAA and 2% sucrose. Subculture of somatic embryos onto hormone free MS medium resulted in their conversion into plants for all genotypes. About 95% of the regenerated somatic embryos germinated into complete plantlets. The plants showed morphological and growth characteristics similar to those of seed-derived plants. Explants were transformed using Agrobacterium tumifacious LBA4404 plasmid pCAMBIA1301 harboring the GUS gene. The regenerated transgenic plants were confirmed by PCR analysis and histochemical GUS assay. The transformation efficiency obtained by using the Agrobacterium- mediated transformation was more than 95%. This method takes 6 wk to accomplish complete transgenic plants through direct somatic embryogenesis. The transgenic plantlets were acclimatized successfully with 98% survival in greenhouse and they showed normal morphological characteristics and were fertile. The regeneration and transformation method described herein is very simple, highly efficient and fast for the introduction of any foreign gene directly in tobacco through direct somatic embryogenesis. PMID:23518589

  3. Pine somatic embryogenesis using zygotic embryos as explants.

    PubMed

    Pullman, Gerald S; Bucalo, Kylie

    2011-01-01

    Somatic embryogenesis (SE) has the potential to be the lowest-cost method to rapidly produce large numbers of high-value somatic seedlings with desired characteristics for plantation forestry. At least 24 of the 115-120 known Pinus species can undergo SE. Initiation for most species works best with immature megagametophytes as starting material, although a few pines can initiate SE cultures from isolated mature seed embryos. Successful initiation depends heavily on explant type, embryo developmental stage, and medium salt base. Most first reports of initiation used 2,4-D and BAP or a combination of cytokinins. More recent reports have optimized initiation for many Pinus spp., but still use mostly the combinations of auxin and cytokinins. Initiation can be stimulated with medium supplements including abscisic acid (ABA), brassinosteroids, ethylene inhibitors, gibberellin inhibitors, organic acids, putrescine, specific sugar types (maltose, galactose, D-chiro-inositol, and D-xylose), triacontanol, vitamins (B12, biotin, vitamin E, and folic acid), or manipulation of environmental factors including pH, water potential, cone cold storage, gelling agent concentration, and liquid medium. Embryo development and maturation usually occur best on medium containing ABA along with water potential reduction (with sugars and polyethylene glycol) or water availability reduction (with raised gelling agent increasing gel-strength). Activated carbon and maltose may also improve embryo maturation. The main issues holding SE technology back are related to the high cost of producing a somatic seedling, incurred from low initiation percentages for recalcitrant species, culture loss, and decline after initiation and poor embryo maturation resulting in no or poor germination. Although vast progress has been made in pine SE technology over the past 24 years, fundamental studies on seed and embryo physiology, biochemistry, and gene expression are still needed to help improve the technology to a point where large-scale commercialization is economically viable for a broad range of pine species. PMID:21207275

  4. Comparison of NAA and 2,4-D induced somatic embryogenesis in Cassava

    Microsoft Academic Search

    E. Sofiari; C. J. J. M. Raemakers; E. Kanju; K. Danso; A. M. van Lammeren; E. Jacobsen; R. G. F. Visser

    1997-01-01

    NAA and 2,4-D were compared for their ability to induce somatic embryogenesis in cassava (Manihot esculenta Crantz). In all seven cultivars tested, only 2,4-D had the capacity to induce primary somatic embryos from leaf explants,\\u000a however, both NAA and 2,4-D were capable of inducing secondary somatic embryos. More secondary somatic embryos were formed\\u000a in NAA than in 2,4-D medium. Furthermore,

  5. Influence of Abscisic Acid and Sucrose on Somatic Embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa

    PubMed Central

    Lema-Rumi?ska, J.; Goncerzewicz, K.; Gabriel, M.

    2013-01-01

    Having produced the embryos of cactus Copiapoa tenuissima Ritt. forma monstruosa at the globular stage and callus, we investigated the effect of abscisic acid (ABA) in the following concentrations: 0, 0.1, 1, 10, and 100??M on successive stages of direct (DSE) and indirect somatic embryogenesis (ISE). In the indirect somatic embryogenesis process we also investigated a combined effect of ABA (0, 0.1, 1??M) and sucrose (1, 3, 5%). The results showed that a low concentration of ABA (0-1??M) stimulates the elongation of embryos at the globular stage and the number of correct embryos in direct somatic embryogenesis, while a high ABA concentration (10–100??M) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somatic embryogenesis study in this cactus suggests that lower ABA concentrations enhance the increase in calli fresh weight, while a high concentration of 10??M ABA or more changes calli color and decreases its proliferation rate. However, in the case of indirect somatic embryogenesis, ABA had no effect on the number of somatic embryos and their maturation. Nevertheless, we found a positive effect of sucrose concentration for both the number of somatic embryos and the increase in calli fresh weight. PMID:23843737

  6. Effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum

    Microsoft Academic Search

    Cui Kairong; Li Ji; Xing Gengmei; Li Jianlong; Wang Lihong; Wang Yafu

    2002-01-01

    Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somatic embryogenesis. The effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum L. was studied. One-dimensional gel electrophoresis showed that new protein was synthesized by embryogenic callus II (in MS+200 µmol l-1 H2O2 medium). Therefore, we suggested that there was a

  7. Effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum

    Microsoft Academic Search

    Cui Kairong; Xing Gengmei; Wang Lihong; Wang Yafu

    2002-01-01

    Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somatic embryogenesis. The effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum L. was studied. One-dimensional gel electrophoresis showed that new protein was synthesized by embryogenic callus II (in MS+200 µmol l?1 H2O2 medium). Therefore, we suggested that there was a

  8. Proteomic Analysis of Immature Fraxinus mandshurica Cotyledon Tissues during Somatic Embryogenesis: Effects of Explant Browning on Somatic Embryogenesis

    PubMed Central

    Liu, Chun-Ping; Yang, Ling; Shen, Hai-Long

    2015-01-01

    Manchurian ash (Fraxinus mandshurica Rupr.) is a valuable hardwood species in Northeast China. In cultures of F. mandshurica, somatic embryos were produced mainly on browned explants. Therefore, we studied the mechanism of explant browning and its relationship with somatic embryogenesis (SE). We used explants derived from F. mandshurica immature zygotic embryo cotyledons as materials. Proteins were extracted from browned embryogenic explants, browned non-embryogenic explants, and non-brown explants, and then separated by 2-dimensional electrophoresis. Differentially and specifically expressed proteins were analyzed by mass spectrometry to identify proteins involved in the browning of explants and SE. Some stress response and defense proteins such as chitinases, peroxidases, aspartic proteinases, and an osmotin-like protein played important roles during SE of F. mandshurica. Our results indicated that explant browning might not be caused by the accumulation and oxidation of polyphenols only, but also by some stress-related processes, which were involved in programmed cell death (PCD), and then induced SE. PMID:26084048

  9. Proteomic Analysis of Immature Fraxinus mandshurica Cotyledon Tissues during Somatic Embryogenesis: Effects of Explant Browning on Somatic Embryogenesis.

    PubMed

    Liu, Chun-Ping; Yang, Ling; Shen, Hai-Long

    2015-01-01

    Manchurian ash (Fraxinus mandshurica Rupr.) is a valuable hardwood species in Northeast China. In cultures of F. mandshurica, somatic embryos were produced mainly on browned explants. Therefore, we studied the mechanism of explant browning and its relationship with somatic embryogenesis (SE). We used explants derived from F. mandshurica immature zygotic embryo cotyledons as materials. Proteins were extracted from browned embryogenic explants, browned non-embryogenic explants, and non-brown explants, and then separated by 2-dimensional electrophoresis. Differentially and specifically expressed proteins were analyzed by mass spectrometry to identify proteins involved in the browning of explants and SE. Some stress response and defense proteins such as chitinases, peroxidases, aspartic proteinases, and an osmotin-like protein played important roles during SE of F. mandshurica. Our results indicated that explant browning might not be caused by the accumulation and oxidation of polyphenols only, but also by some stress-related processes, which were involved in programmed cell death (PCD), and then induced SE. PMID:26084048

  10. Somatic embryogenesis and plant regeneration from leaf tissue of jojoba

    Microsoft Academic Search

    L. Hamama; M. Baaziz; R. Letouzé

    2001-01-01

    A protocol was developed for the induction, maturation and germination of somatic embryos from leaf tissue of jojoba [Simmondsia chinensis (Link) Schneider]. Explants were placed on their adaxial sides in Petri dishes and maintained in darkness on half-strength\\u000a Murashige and Skoog basal medium (MS\\/2). Combinations of 2,4-dichlorophenoxyacetic acid (1.35–4.52 ?M) with 6-benzylaminopurine\\u000a (1.33–4.43?M) and 2 synthetic cytokinins, N-(2-chloro-4pyridyl)-N?-phenylurea (1.21–4.03?M) or

  11. Ammonium nitrate improves direct somatic embryogenesis and biolistic transformation of Triticum aestivum.

    PubMed

    Greer, Michael S; Kovalchuk, Igor; Eudes, Francois

    2009-10-01

    Triticum aestivum is of major importance both nutritionally and economically. Introduction of new genes has been difficult to apply to elite wheat varieties mainly as a result of their recalcitrance to prerequisite tissue culture. We attempted to improve the frequency of wheat transformation by exposing plants to high level of ammonium nitrate. Our experiments showed that modification of the ammonium nitrate content in the direct somatic embryogenesis induction medium can increase the number of primary embryos produced over twofold in the elite hard red wheat cultivar Superb. The number of primary embryos that were capable of transitioning into shoot development also increased twofold. Biolistic transformation efficiency improved as much as sevenfold when targeted scutellar tissue was exposed to elevated ammonium nitrate levels. This simple approach could become extremely useful for increasing transformation efficiency in wheat. PMID:19818315

  12. Improved efficiency of somatic embryogenesis from zygotic embryos in Hyoscyamus niger by seed water-soaking

    Microsoft Academic Search

    Shanjun Tu; R. S. Sangwan; B. S. Sangwan-Norreel

    2005-01-01

    We describe an efficient procedure to obtain somatic embryos from mature zygotic embryos of Hyoscyamus niger (black henbane). It has several advantages over previous regeneration methods, which are: the use of mature seeds, an average 80% somatic embryogenesis rate and a high (eight-fold higher than the control) plant regeneration frequency. The critical step in this protocol was soaking of the

  13. Screening of diploid Medicago sativa germplasm for somatic embryogenesis.

    PubMed

    Meijer, E G; Brown, D C

    1985-10-01

    Nineteen accessions of diploid Medicago sativa L. belonging to the four subspecies sativa, caerula, falcata and xvaria were screened for their ability to produce somatic embryos on hypocotyl-derived callus. Two medium protocols were used in this study, a three-step sequence with exposure of the callus cultures to a high 2,4-D concentration and a two-step sequence without exposure to a high 2,4-D concentration. Considerable variation for callus proliferation was observed. In general, the diploid M. sativa accessions showed poor regenerability and it was not possible to correlate high regeneration frequencies with a particular germplasm source. It was, however, possible to identify regenerable genotypes in all four subspecies. One falcata accession produced somatic embryos on the callus induction media at high frequencies. This response was also obtained with a few genotypes from one xvaria accession. All regenerable plants were maintained as shoot cultures and were able to form somatic embryos on petiole-derived calli. PMID:24253990

  14. Somatic Embryogenesis, Rhizogenesis, and Morphinan Alkaloids Production in Two Species of Opium Poppy.

    PubMed

    Kassem, My Abdelmajid; Jacquin, Annie

    2001-01-01

    A study of somatic embryogenesis and rhizogenesis and their influence on production of morphinan alkaloids on two species of opium poppy is presented. We identified the ratios of auxin and cytokinin that caused somatic embryogenesis and rhizogenesis in hypocotyl and cotyledons of Papaver somniferum album and Papaver orientale splendidissimum. The hypocotyls and cotyledons both show somatic embryogenesis in Papaver somniferum album whereas only the cotyledons were embryogenic in Papaver orientale splendidissimum. For rhizogenesis, the most important response is on the cotyledons and leaves in these two species. Histology showed characteristic stages of somatic embryo: Globular, cotyledonous, and heart cotyledonary. High performance liquid chromatography analysis showed that the roots of both species synthesized codeine, thebaine, and papaverine. Morphine was only detected in aerial parts of Papaver somniferum album. Codeine and thebaine were detected in the rhizogenous but no embryonic callus. These results suggest that root organogenesis is causally related to alkaloid biosynthesis. PMID:12488612

  15. Amplified somatic embryogenesis from male flowers of triploid banana and plantain cultivars ( Musa spp.)

    Microsoft Academic Search

    Jean-Vincent Escalant; Claude Teisson; François Cote

    1994-01-01

    Summary  Somatic embryogenesis and plant regeneration of banana and plantain cultivars (Musa spp.) were obtained by culturing young male flowers. Multiplication and maintenance of embryogenic cultures were achieved\\u000a by culturing somatic embryos in a temporary immersion system (SIT). A multiplication rate of 40 allowed us to obtain more\\u000a than 6000 somatic embryos after 6 mo. of subculture. Plant recovery frequencies were

  16. Analysis of the rolC promoter region involved in somatic embryogenesis-related activation in carrot cell cultures.

    PubMed Central

    Fujii, N; Yokoyama, R; Uchimiya, H

    1994-01-01

    In cell cultures of carrot (Daucus carota L.), somatic embryogenesis can be induced by transferring cells from a medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) to one devoid of 2,4-D. Previous analysis of transgenic carrot cells containing the 5' non-coding sequence of the Ri plasmid rolC and a structural gene for bacterial beta-glucuronidase (uidA) has shown that the chimeric gene is actively expressed after induction of somatic embryogenesis. In this study, we demonstrate that activation of the rolC promoter is dependent on the process of embryo development but not on the duration of the cell culture in 2,4-D-free medium. We also analyzed the cis region of the rolC promoter that is responsible for somatic embryogenesis-related activation (SERA), namely relatively low beta-glucuronidase (GUS) activity in calli and proembryogenic masses (PEM) and high GUS activity in heart- and torpedo-stage embryos. When the -255-bp region of the rolC gene was used, SERA was retained. Internal deletions within this -255-bp region did not alter SERA by the rolC promoter. Furthermore, when a rolC promoter fragment (-848 to -94 bp) was fused to the cauliflower mosaic virus (CaMV) 35S core region (-90 to +6 bp), it conferred relatively low GUS activity in calli and PEM but high GUS activity in heart and torpedo embryos. When -848 to -255-bp or -255- to -94-bp fragments of the rolC promoter were fused to the same CaMV 35S core region, GUS activity patterns were not related to somatic embryogenesis. These results suggest that the combination of several regulatory regions in the rolC promoter may be required for SERA in carrot cell cultures. PMID:8016259

  17. Extensive modulation of the transcription factor transcriptome during somatic embryogenesis in Arabidopsis thaliana.

    PubMed

    Gliwicka, Marta; Nowak, Katarzyna; Balazadeh, Salma; Mueller-Roeber, Bernd; Gaj, Malgorzata D

    2013-01-01

    Molecular mechanisms controlling plant totipotency are largely unknown and studies on somatic embryogenesis (SE), the process through which already differentiated cells reverse their developmental program and become embryogenic, provide a unique means for deciphering molecular mechanisms controlling developmental plasticity of somatic cells. Among various factors essential for embryogenic transition of somatic cells transcription factors (TFs), crucial regulators of genetic programs, are believed to play a central role. Herein, we used quantitative real-time polymerase chain reaction (qRT-PCR) to identify TF genes affected during SE induced by in vitro culture in Arabidopsis thaliana. Expression profiles of 1,880 TFs were evaluated in the highly embryogenic Col-0 accession and the non-embryogenic tanmei/emb2757 mutant. Our study revealed 729 TFs whose expression changes during the 10-days incubation period of SE; 141 TFs displayed distinct differences in expression patterns in embryogenic versus non-embryogenic cultures. The embryo-induction stage of SE occurring during the first 5 days of culture was associated with a robust and dramatic change of the TF transcriptome characterized by the drastic up-regulation of the expression of a great majority (over 80%) of the TFs active during embryogenic culture. In contrast to SE induction, the advanced stage of embryo formation showed attenuation and stabilization of transcript levels of many TFs. In total, 519 of the SE-modulated TFs were functionally annotated and transcripts related with plant development, phytohormones and stress responses were found to be most abundant. The involvement of selected TFs in SE was verified using T-DNA insertion lines and a significantly reduced embryogenic response was found for the majority of them. This study provides comprehensive data focused on the expression of TF genes during SE and suggests directions for further research on functional genomics of SE. PMID:23874927

  18. Somatic embryogenesis in white spruce ( Picea glauca ): genetic control in somatic embryos exposed to storage, maturation treatments, germination, and cryopreservation

    Microsoft Academic Search

    Y. S. Park; S. E. Pond; J. M. Bonga

    1994-01-01

    Genetic controls for growth of embryogenic cultures, storage, maturation treatments, germination and cryopreservation in white spruce somatic embryogenesis (SE) were examined. These SE processes were under genetic control but less strongly so than the initiation phase. For all the SE characters examined, variance due to clones within families was significant and often the largest genetic component of variance. This was

  19. Establishment of embryonic shoot–root axis is involved in auxin and cytokinin response during Arabidopsis somatic embryogenesis

    PubMed Central

    Su, Ying Hua; Liu, Yu Bo; Bai, Bo; Zhang, Xian Sheng

    2015-01-01

    Auxin and cytokinin signaling participates in regulating a large spectrum of developmental and physiological processes in plants. The shoots and roots of plants have specific and sometimes even contrary responses to these hormones. Recent studies have clearly shown that establishing the spatiotemporal distribution of auxin and cytokinin response signals is central for the control of shoot apical meristem (SAM) induction in cultured tissues. However, little is known about the role of these hormones in root apical meristem (RAM) initiation. Here, we found that the expression patterns of several regulatory genes critical for RAM formation were correlated with the establishment of the embryonic root meristem during somatic embryogenesis in Arabidopsis. Interestingly, the early expression of the WUS-RELATED HOMEOBOX 5 (WOX5) and WUSCHEL genes was induced and was nearly overlapped within the embryonic callus when somatic embryos (SEs) could not be identified morphologically. Their correct expression was essential for RAM and SAM initiation and embryonic shoot–root axis establishment. Furthermore, we analyzed the auxin and cytokinin response during SE initiation. Notably, cytokinin response signals were detected in specific regions that were correlated with induced WOX5 expression and subsequent SE formation. Overexpression of the ARABIDOPSIS RESPONSE REGULATOR genes ARR7 and ARR15 (feedback repressors of cytokinin signaling), disturbed RAM initiation and SE induction. These results provide new information on auxin and cytokinin-regulated apical–basal polarity formation of shoot–root axis during somatic embryogenesis. PMID:25642237

  20. Microarray Analysis of Siberian Ginseng Cyclic Somatic Embryogenesis Culture Systems Provides Insight into Molecular Mechanisms of Embryogenic Cell Cluster Generation

    PubMed Central

    Zhou, Chenguang; Liu, Likun; Li, Chenghao

    2014-01-01

    Four systems of cyclic somatic embryogenesis of Siberian ginseng (Eleutherococcus senticosus Maxim) were used to study the mechanism of embryonic cell cluster generation. The first, direct somatic embryo induction (DSEI), generates secondary embryos directly from the primary somatic embryos; the second, direct embryogenic cell cluster induction (DEC)), induces embryogenic cell clusters directly from somatic embryos in agar medium. Subsequently, we found that when DEC-derived somatic embryos are transferred to suspension culture or a bioreactor culture, only somatic embryos are induced, and embryogenic cell clusters cannot form. Therefore, these new lines were named DEC cultured by liquid medium (ECS) and DEC cultured by bioreactor (ECB), respectively. Transmission electron microscopy showed that DEC epidermal cells contained a variety of inclusions, distinct from other lines. A cDNA library of DEC was constructed, and 1,948 gene clusters were obtained and used as probes. RNA was prepared from somatic embryos from each of the four lines and hybridized to a microarray. In DEC, 7 genes were specifically upregulated compared with the other three lines, and 4 genes were downregulated. EsXTH1 and EsPLT1, which were among the genes upregulated in DEC, were cloned using the rapid amplification of cDNA ends (RACE). Real-time quantitative PCR showed EsXTH1 was more highly expressed in DEC than in other lines throughout the culture cycle, and EsPLT1 expression in DEC increased as culture duration increased, but remained at a low expression level in other lines. These results suggest that EsXTH1 and EsPLT1 may be the essential genes that play important roles during the induction of embryogenic cell clusters. PMID:24743225

  1. Differential regulation of SERK, LEC1-like and pathogenesis-related genes during indirect secondary somatic embryogenesis in grapevine.

    PubMed

    Maillot, Pascale; Lebel, Sylvain; Schellenbaum, Paul; Jacques, Alban; Walter, Bernard

    2009-08-01

    A culture model was developed in Vitis vinifera L., cultivar 'Chardonnay' for studying SE (Somatic Embryogenesis). The auxin 2,4-D (2,4-Dichlorophenoxyacetic acid) was used to induce indirect secondary embryogenesis at a high rate, starting from embryos derived from embryogenic cultures previously obtained. Cotyledonary embryos were shown to be more responsive to SE induction than embryos at the torpedo-stage and were used for molecular analyses. The expression of SERK (Somatic Embryogenesis Receptor Kinase), L1L (Leafy Cotyledon1 Like) and a set of PR (Pathogenesis-Related) genes was monitored during the whole SE process. VvSERK1, VvSERK2 and VvL1L were down-regulated by the 2,4-D treatment but expressed in embryonic tissues. On the contrary, VvPR1, VvPR8, VvPR10.1 and VvPR10.3 were strongly up-regulated by the 2,4-D treatment, and their transcripts were not or only weakly detected in clusters of secondary embryos. VvSERK3, VvPR3 and VvPR10.2 were more stably expressed in all tissues examined. The discussion deals with the putative role of the different genes in grapevine SE. PMID:19406655

  2. Whole Transcriptome Profiling of Maize during Early Somatic Embryogenesis Reveals Altered Expression of Stress Factors and Embryogenesis-Related Genes

    PubMed Central

    Salvo, Stella A. G. D.; Hirsch, Candice N.; Buell, C. Robin; Kaeppler, Shawn M.; Kaeppler, Heidi F.

    2014-01-01

    Embryogenic tissue culture systems are utilized in propagation and genetic engineering of crop plants, but applications are limited by genotype-dependent culture response. To date, few genes necessary for embryogenic callus formation have been identified or characterized. The goal of this research was to enhance our understanding of gene expression during maize embryogenic tissue culture initiation. In this study, we highlight the expression of candidate genes that have been previously regarded in the literature as having important roles in somatic embryogenesis. We utilized RNA based sequencing (RNA-seq) to characterize the transcriptome of immature embryo explants of the highly embryogenic and regenerable maize genotype A188 at 0, 24, 36, 48, and 72 hours after placement of explants on tissue culture initiation medium. Genes annotated as functioning in stress response, such as glutathione-S-transferases and germin-like proteins, and genes involved with hormone transport, such as PINFORMED, increased in expression over 8-fold in the study. Maize genes with high sequence similarity to genes previously described in the initiation of embryogenic cultures, such as transcription factors BABY BOOM, LEAFY COTYLEDON, and AGAMOUS, and important receptor-like kinases such as SOMATIC EMBRYOGENESIS RECEPTOR LIKE KINASES and CLAVATA, were also expressed in this time course study. By combining results from whole genome transcriptome analysis with an in depth review of key genes that play a role in the onset of embryogenesis, we propose a model of coordinated expression of somatic embryogenesis-related genes, providing an improved understanding of genomic factors involved in the early steps of embryogenic culture initiation in maize and other plant species. PMID:25356773

  3. Somatic embryogenesis, scanning electron microscopy, histology and biochemical analysis at different developing stages of embryogenesis in six date palm (Phoenix dactylifera L.) cultivars

    PubMed Central

    Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker

    2011-01-01

    An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1?l). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1?1) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N6-benzyladenine (BAP, 0.75 mg 1?l) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1?l) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further. PMID:23961149

  4. Elimination of Grapevine fanleaf virus from three Vitis vinifera cultivars by somatic embryogenesis

    Microsoft Academic Search

    Giorgio Gambino; Daniele Di Matteo; Ivana Gribaudo

    2009-01-01

    Indirect somatic embryogenesis was tested as a method for eradication of Grapevine fanleaf virus (GFLV) in three grapevine cultivars. Reverse transcriptase-polymerase chain reaction for GFLV detection was performed on\\u000a tissues sampled at various steps of the embryogenic process: flower explants, embryogenic and non-embryogenic calli, single\\u000a somatic embryos and regenerated plants. The virus was detected in all tested anthers and ovaries,

  5. The effectiveness of somatic embryogenesis in eliminating the cocoa swollen shoot virus from infected cocoa trees

    Microsoft Academic Search

    A. K. Quainoo; A. C. Wetten; J. Allainguillaume

    2008-01-01

    Investigations were undertaken on the use of somatic embryogenesis to generate cocoa swollen shoot virus (CSSV) disease free clonal propagules from infected trees. Polymerase chain reaction (PCR) capillary electrophoresis revealed the presence of CSSV in all the callus tissues induced from the CSSV-infected Amelonado cocoa trees (T1, T2 and T4). The virus was transmitted to primary somatic embryos induced from

  6. Changes in soluble carbohydrates and starch amounts during somatic and zygotic embryogenesis of Acca sellowiana (Myrtaceae)

    Microsoft Academic Search

    Rosete Pescador; Gilberto B. Kerbauy; Jane E. Kraus; Wagner de Melo Ferreira; Miguel Pedro Guerra; Rita de Cássia L. Figueiredo-Ribeiro

    2008-01-01

    Comparative analysis of zygotic and somatic embryogenesis of Acca sellowiana showed higher amounts of sucrose, fructose, raffinose, and myo-inositol in zygotic embryos at different developmental stages than in corresponding somatic ones. These differences were\\u000a mostly constant. In general, glucose levels were significantly lower than the other soluble carbohydrates analyzed, showing\\u000a minor variation in each embryo stage. Despite the presence of

  7. Evidence for in vitro induced mutation which improves somatic embryogenesis in Asparagus officinalis L

    Microsoft Academic Search

    B. Delbreil; M. Jullien

    1994-01-01

    Summary  Somatic embryogenesis from different genotypes of Asparagus officinalis L. could be obtained by in vitro culture of shoot apices. Apices were first cultured on an auxin-rich inducing medium and then transferred onto a hormone-free development medium. All genotypes tested in this way produced a few somatic embryos. In some experiments, during the development phase, a new kind of friable highly

  8. The effectiveness of somatic embryogenesis in eliminating the cocoa swollen shoot virus from infected cocoa trees.

    PubMed

    Quainoo, A K; Wetten, A C; Allainguillaume, J

    2008-04-01

    Investigations were undertaken on the use of somatic embryogenesis to generate cocoa swollen shoot virus (CSSV) disease free clonal propagules from infected trees. Polymerase chain reaction (PCR) capillary electrophoresis revealed the presence of CSSV in all the callus tissues induced from the CSSV-infected Amelonado cocoa trees (T1, T2 and T4). The virus was transmitted to primary somatic embryos induced from the infected callus tissues at the rate of 10 (19%), 18 (14%) and 16 (15%) for T1, T2 and T4, respectively. Virus free primary somatic embryos from the infected callus tissues converted into plantlets tested CSSV negative by PCR/capillary electrophoresis 2 years after weaning. Secondary somatic embryos induced from the CSSV-infected primary somatic embryos revealed the presence of viral fragments at the rate of 4 (4%) and 9 (9%) for T2 and T4, respectively. Real-time PCR revealed 23 of the 24 secondary somatic embryos contained no detectable virus. Based on these findings, it is proposed that progressive elimination of the CSSV in infected cocoa trees occurred from primary embryogenesis to secondary embryogenesis. PMID:18294704

  9. The effectiveness of various nitrogen sources in white spruce [ Picea glauca (Moench) Voss] somatic embryogenesis

    Microsoft Academic Search

    J. D. Barrett; Y. S. Park; J. M. Bonga

    1997-01-01

    The effects of glutamine-based dipeptides, glutamine and casein hydrolysate, as well as the deletion of organic nitrogen, were investigated during white spruce [Picea glauca (Moench) Voss] somatic embryogenesis. There were no differences in the fresh weight increase of the tissue masses grown on initiation medium with different combinations of organic nitrogen. This was also the case for subsequent growth on

  10. Localization and Identification of Phenolic Compounds in Theobroma cacao L. Somatic Embryogenesis

    PubMed Central

    ALEMANNO, L.; RAMOS, T.; GARGADENEC, A.; ANDARY, C.; FERRIERE, N.

    2003-01-01

    Cocoa breeders and growers continue to face the problem of high heterogeneity between individuals derived from one progeny. Vegetative propagation by somatic embryogenesis could be a way to increase genetic gains in the field. Somatic embryogenesis in cocoa is difficult and this species is considered as recalcitrant. This study was conducted to investigate the phenolic composition of cocoa flowers (the explants used to achieve somatic embryogenesis) and how it changes during the process, by means of histochemistry and conventional chemical techniques. In flowers, all parts contained polyphenolics but their locations were specific to the organ considered. After placing floral explants in vitro, the polyphenolic content was qualitatively modified and maintained in the calli throughout the culture process. Among the new polyphenolics, the three most abundant were isolated and characterized by 1H? and 13C?NMR. They were hydroxycinnamic acid amides: N?trans?caffeoyl?l?DOPA or clovamide, N?trans?p?coumaroyl?l?tyrosine or deoxiclovamide, and N?trans?caffeoyl?l?tyrosine. The same compounds were found also in fresh, unfermented cocoa beans. The synthesis kinetics for these compounds in calli, under different somatic embryogenesis conditions, revealed a higher concentration under non?embryogenic conditions. Given the antioxidant nature of these compounds, they could reflect the stress status of the tissues. PMID:12933367

  11. Localization and identification of phenolic compounds in Theobroma cacao L. somatic embryogenesis.

    PubMed

    Alemanno, L; Ramos, T; Gargadenec, A; Andary, C; Ferriere, N

    2003-10-01

    Cocoa breeders and growers continue to face the problem of high heterogeneity between individuals derived from one progeny. Vegetative propagation by somatic embryogenesis could be a way to increase genetic gains in the field. Somatic embryogenesis in cocoa is difficult and this species is considered as recalcitrant. This study was conducted to investigate the phenolic composition of cocoa flowers (the explants used to achieve somatic embryogenesis) and how it changes during the process, by means of histochemistry and conventional chemical techniques. In flowers, all parts contained polyphenolics but their locations were specific to the organ considered. After placing floral explants in vitro, the polyphenolic content was qualitatively modified and maintained in the calli throughout the culture process. Among the new polyphenolics, the three most abundant were isolated and characterized by 1H- and 13C-NMR. They were hydroxycinnamic acid amides: N-trans-caffeoyl-l-DOPA or clovamide, N-trans-p-coumaroyl-l-tyrosine or deoxiclovamide, and N-trans-caffeoyl-l-tyrosine. The same compounds were found also in fresh, unfermented cocoa beans. The synthesis kinetics for these compounds in calli, under different somatic embryogenesis conditions, revealed a higher concentration under non-embryogenic conditions. Given the antioxidant nature of these compounds, they could reflect the stress status of the tissues. PMID:12933367

  12. Influence of low temperature preincubation on somatic embryogenesis and ethylene emanation from orchardgrass leaves

    Microsoft Academic Search

    Z. Tomaszewski Jr; A. I. Kuklin; C. E. Sams; B. V. Conger

    1994-01-01

    The objectives of this study were to determine the effects of low temperature (4 °C) preincubation on somatic embryogenesis from orchardgrass (Dactylis glomerata L.) leaf cultures and to relate these effects to ethylene emanation during the preincubation and incubation periods. Experiments were also conducted with an ethylene biosynthesis inhibitor aminooxyacetic acid (AOA). Segments from the innermost two leaves were cultured

  13. Alfalfa embryo production in airlift vessels via direct somatic embryogenesis

    Microsoft Academic Search

    Alexander I. Kuklin; Plamen D. Denchev; Atanas I. Atanassov; Alan H. Scragg

    1994-01-01

    A procedure for the development of alfalfa (Medicago falcata L.) somatic embryos to the torpedo stage in air-lift vessels is described. Embryos were initiated from chopped leaf explants and were formed by direct somatic embryogensis. The system produced a high number of torpedo stage embryos. The effect of various inoculation densities on embryo development was studied. A procedure for the

  14. Improvement of somatic embryogenesis and plant recovery in cassava

    Microsoft Academic Search

    Helena Mathews; C. Schopke; R. Carcamo; P. Chavarriaga; C. Fauquet; R. N. Beachy

    1993-01-01

    Methods for improving the efficiency of plant recovery from somatic embryos of cassava (Manihot esculenta Crantz) were investigated by optimizing the maturation regime and incorporating a desiccation stage prior to inducing germination. Somatic embryos were induced from young leaf lobes of in vitro grown shoots of cassava on Murashige and Skoog medium with 2,4-dichlorophenoxy acetic acid. After 15 to 20

  15. Assessment of ploidy stability of the somatic embryogenesis process in Quercus suber L. using flow cytometry.

    PubMed

    Loureiro, J; Pinto, G; Lopes, T; Dolezel, J; Santos, C

    2005-08-01

    Flow cytometry analyses were used to verify the ploidy stability of Quercus suber L. somatic embryogenesis process. Leaf explants of two adult cork oak trees (QsG0 and QsG5) of the North of Portugal were inoculated on MS medium with 2,4-D and zeatin. After 3 months, calluses with embryogenic structures were isolated and transferred to fresh MS medium without growth regulators and somatic embryo evolution was followed. Morphologically normal somatic embryos (with two cotyledons) and abnormal somatic embryos (with one or three cotyledons) were used in this assay. Flow cytometry combined with propidium iodide staining was employed to estimate DNA ploidy levels and nuclear DNA content of somatic embryos and leaves from mother plants. No significant differences (P< or =0.05) were detected among embryos, and between the embryos and the mother plants. Also, after conversion of these embryos, no significant morphological differences were observed among the somatic embryo-derived plants. These results and further studies using converted plantlet leaves and embryogenic callus tissue indicate that embryo cultures and converted plantlets were stable with regard to ploidy level. As no major somaclonal variation was detected our primary goal of "true-to-type" propagation of cork oak using somatic embryogenesis was assured at this level. The estimation of the 2C nuclear DNA content for this species is similar to the previously obtained value. PMID:15744492

  16. Production of plants resistant to Alternaria carthami via organogenesis and somatic embryogenesis of safflower cv. NARI-6 treated with fungal culture filtrates

    Microsoft Academic Search

    J. Vijaya Kumar; B. D. Ranjitha Kumari; G. Sujatha; Enrique Castaño

    2008-01-01

    The present study describes a system for efficient plant regeneration via organogenesis and somatic embryogenesis of safflower\\u000a (Carthamus\\u000a tinctorius L.) cv. NARI-6 in fungal culture filtrates (FCF)-treated cultures. FCF was prepared by culturing Alternaria carthami fungal mycelia in selection medium for host-specific toxin production. Cotyledon explants cultured on callus induction medium\\u000a with different levels of FCF (10–50%) produced embryogenic callus.

  17. Somatic embryogenesis and plant regeneration from immature embryo cultures of onion (Allium cepa L.)

    Microsoft Academic Search

    C. C. Eady; R. C. Butler; Y. Suo

    1998-01-01

    Somatic embryos were obtained and plants regenerated from immature embryos of onion following culture on embryogenic induction\\u000a media. Highest rates of somatic embrogenesis resulted from 0.5- to 1.5-mm immature embryos cultured on media containing 5\\u000a mg\\/l of picloram. Somatic embryos formed either directly on the surface of embryos or developed from compact cultures. The\\u000a production of somatic embryos was significantly

  18. Somatic embryogenesis and Agrobacterium -mediated transformation in Bixa orellana L

    Microsoft Academic Search

    Rangan Parimalan; Akshatha Venugopalan; Parvatam Giridhar; G. A. Ravishankar

    2011-01-01

    Establishment, maintenance, regeneration, and transformation of somatic embryos by both direct and indirect means (callus-mediated)\\u000a was achieved for Bixa orellana, a tropical plant whose seeds produce commercially edible ‘annatto pigment,’ which mainly constitutes an apocarotenoid called\\u000a bixin. Callus-mediated methodology was found to be efficient in producing a greater number of embryos in a short time. The\\u000a maximum of 28 somatic

  19. Influence of antibiotic cefotaxime on somatic embryogenesis and plant regeneration in indica rice.

    PubMed

    Grewal, Deepinder; Gill, Raman; Gosal, Satbir Singh

    2006-10-01

    An antibiotic, cefotaxime (Omnatax) has been found to promote somatic embryogenesis and subsequent plant regeneration in vitro in indica-type basmati rice cultures. Response was highly genotype specific. The number, mass and morphology of the calli formed on the scutellar tissues were dependent on the growth medium (with or without cefotaxime). The embryogenic nature of nodular calli was confirmed through histological analysis and their plant regeneration ability. The calli of variety Pusa basmati 1 grown on medium supplemented with cefotaxime (100 mg/L) exhibited up to 70.5% plant regeneration as compared to control (51.51%). Plants regenerated from emryogenic calli were phenotypically normal and identical to seed-derived plants and exhibited normal fertility. A limited humidity and an optimal aeration of the culture tubes further enhanced the frequency of somatic embryogenesis and plant regeneration. PMID:17125131

  20. Regeneration of Plants Through Somatic Embryogenesis in Emilia zeylanica C. B. Clarke a Potential Medicinal Herb

    Microsoft Academic Search

    Jayachandran Philip Robinson; S. John Britto; V. Balakrishnan

    Tissue culture techniques are useful for ex situ conservation of rare, endemic or threatened plant species. This report describes a protocol for somatic embryogenesis of Emilia zeylanica (Asteraceae) a rare medicinal plant species, using stem explants. Highest frequency of embryogenic callus formation obtained from stem explants on MS media supplemented with KIN (0.50 mg\\/l) and 2, 4- D (0.10 mg\\/l).

  1. Somatic embryogenesis and plant regeneration from root sections of Allium schoenoprasum L

    Microsoft Academic Search

    S. Zdravkovi?-Kora?; J. Milojevic ´; Lj. Tubi?; D. ?ali?-Dragosavac; N. Miti?; B. Vinterhalter

    2010-01-01

    A protocol has been developed for somatic embryogenesis and subsequent plant regeneration in Allium schoenoprasum L. Calli were induced from root sections isolated from axenic seedlings and cultivated on media containing either Murashige\\u000a and Skoog’s (MS) or Dunstan and Short’s mineral solution supplemented with 5 ?M 2,4-dichlorophenoxyacetic acid (2,4-D) in\\u000a combination with 6-benzylaminopurine (BA), 6-furfurylaminopurine (Kin) or thidiazuron (TDZ) at 1,

  2. Somatic embryogenesis and plant regeneration in cultured immature inflorescences of Setaria italica

    Microsoft Academic Search

    Zhi-hong Xu; Da-yuan Wang; Li-jun Yang; Zhi-ming Wei

    1984-01-01

    Young inflorescence explants of Setaria italica in culture showed high capacity for regenerating plantlets through somatic embryogenesis. Embryogenic callus formation was initiated from the explants cultured on Murashige and Skoog's medium with 2 mg\\/l 2,4-D and 0.2–0.5 mg\\/l KT or BAP, but it was better for the maintenance of embryogenic growth to subculture the calli on the medium with 2,4-D

  3. High frequency somatic embryogenesis and plant regeneration from papaya hypocotyl callus

    Microsoft Academic Search

    Maureen M. M. Fitch

    1993-01-01

    High frequency somatic embryogenesis in papaya (Carica papaya L.) tissue cultures was achieved by culturing hypocotyl sections from ten-day-old seedlings on half-strength Murashige and Skoog salts (MS) medium containing modified MS vitamins, 2.3 to 112.5 µM 2,4-dichlorophenoxyacetic acid (2,4-d), 400 mg l-1 glutamine, and 6% sucrose. Four hermaphroditic Hawaiian cultivars produced embryogenic calluses after ten to 14 weeks of culture

  4. Indirect somatic embryogenesis and plant regeneration from leaf and internode explants of Paulownia elongata

    Microsoft Academic Search

    Zeliha Ipekci; Nermin Gozukirmizi

    2005-01-01

    Several plant growth regulators BA, TDZ, 2,4- and Kn were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf and internode explants of Paulownia elongata. Calli were produced when leaf explants were cultured on Murashige and Skoog (MS) medium containing 3 % sucrose, 0.4 % phytagel, 4 mg l-1 TDZ and 0.1 mg l-1

  5. Somatic embryogenesis and plant regeneration of Abelmoschus esculentus through suspension culture

    Microsoft Academic Search

    M. Ganesan; R. Chandrasekar; B. D. Ranjitha Kumari; N. Jayabalan

    2007-01-01

    A simple and reliable protocol for regeneration of okra through somatic embryogenesis from suspension cultures has been developed.\\u000a Embryogenic callus was obtained from hypocotyl explants cultured on media with Murashige and Skoog (MS) salts, Gamborg (B5)\\u000a vitamins, 2.0 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D), 1.0 mg dm?3 naphthaleneacetic acid (NAA), 25 mg dm?3 polyvinylpyrrolidone and 30 g dm?3 sucrose. More number

  6. Plant regeneration through somatic embryogenesis from zygotic embryo-derived callus of Areca catechu L. (Arecaceae)

    Microsoft Academic Search

    Hsiang-Chih Wang; Jen-Tsung Chen; Shieh-Ping Wu; Mei-Chun Lin; Wei-Chin Chang

    2003-01-01

    Summary  An in vitro culture procedure was established for somatic embryogenesis and plant regeneration from callus cultures of the important\\u000a palm ‘betel nut’ (Areca catechu L.). Segments of zygotic embryos of Areca catechu L. were cultured on Murashige and Skoog basal medium supplemented with dicamba (9.05, 18.1, 27.15, and 36.2 ?M). After 7–8 wk in darkness, wounded regions of explants formed

  7. Screening of diploid Medicago sativa germplasm for somatic embryogenesis

    Microsoft Academic Search

    Eltjo G. M. Meijer; Daniel C. W. Brown

    1985-01-01

    Nineteen accessions of diploid Medicago sativa L. belonging to the four subspecies sativa, caerula, falcata and xvaria were screened for their ability to produce somatic embryos on hypocotyl-derived callus. Two medium protocols were used in this study, a three-step sequence with exposure of the callus cultures to a high 2,4-D concentration and a two-step sequence without exposure to a high

  8. Somatic embryogenesis and plant regeneration in myrtle (Myrtaceae)

    Microsoft Academic Search

    Jorge M. Canhoto; Maria L. Lopes; Gil S. Cruz

    1999-01-01

    Somatic embryos of myrtle (Myrtus communis L.) were induced from mature zygotic embryos cultured in MS medium supplemented\\u000a with several concentrations of 2,4-D (2.26 ?M – 18.98 ?M) or Picloram (2.07 ?M – 16.5 ?M) combined with 0.087 M or 0.23 M\\u000a sucrose. For all the concentrations of 2,4-D or Picloram tested, 0.087 M sucrose proved to be more effective

  9. Somatic embryogenesis, maturation and DNA transfer in Pinus 

    E-print Network

    Marek, Kimberly Ann

    1994-01-01

    the first report in 1985 (Hakman et al. 1985). Currently, the development of somatic embryos on solid media has been reported in Norway spruce (Picea abies (L. ) Karst) (Hakman et al. 1985; Krogstrup 1986; von Arnold and Hakman 1986), sugar pine (Pinus... slash pine trees (source) were made from an open-pollinated orchard of the Texas Forest Service in Magnolia Springs, Texas during the time interval of June 11, 1991 to July 2, 1991. Cones labeled 1 through 10 correspond to the field identity of each...

  10. Enhanced somatic embryogenesis by salicylic acid of Astragalus adsurgens Pall.: relationship with H 2O 2 production and H 2O 2-metabolizing enzyme activities

    Microsoft Academic Search

    Jian-Ping Luo; Shao-Tong Jiang; Li-Jun Pan

    2001-01-01

    Salicylic acid (SA), when added to the differentiation medium below 200 ?mol\\/l, significantly enhanced somatic embryogenesis in callus culture of Astragalus adsurgens Pall. The highest frequency of somatic embryogenesis occurred at 150 ?mol\\/l SA. Enhanced somatic embryogenesis by SA was accompanied by an increase in the endogenous H2O2 level as compared with controls. This increased endogenous H2O2 level was related

  11. Effect of 2-( n-morpholino)ethanesulfonic acid and myo-inositol on somatic embryogenesis and plant regeneration from zygotic embryos of Hyoscyamus niger L

    Microsoft Academic Search

    Shanjun Tu; Thiérry Tétu; Rajbir S. Sangwan; Brigitte S. Sangwan-Norreel

    1996-01-01

    A rapid and efficient regeneration system via somatic embryogenesis has been developed from zygotic embryos of Hyoscyamus niger (black henbane). The effect of 2-(n-morpholino)ethanesulfonic acid (MES), myo-inositol (MI) and different combinations of them with a number of growth regulators on somatic embryogenesis was evaluated. Maximum frequency of direct somatic embryogenesis and germination (30.6%) was achieved after 2–5 weeks by a

  12. Plant regeneration of Iris pallida Lam. and Iris germanica L. via somatic embryogenesis from leaves, apices and young flowers.

    PubMed

    Jéhan, H; Courtois, D; Ehret, C; Lerch, K; Pétiard, V

    1994-09-01

    Irones are violet-scented ketonic compounds contained in the rhizome of certain species of iris. As cultivation of the iris tends to decrease, a selection program has been initiated to find the best performing clones in terms of growth and yield. Parallel to this selection, in vitro regeneration studies have been carried out in order to multiply interesting clones. A method of rapid multiplication by somatic embryogenesis associated with multibudding was developed. Callus was obtained from leaf bases, flower pieces or rhizome apices; the best explants were flower pieces. The induction media used to obtain embryogenic callus were Murashige & Skoog (1962) media. Assays with adding of proline in these media have showed that it could double the yield of embryogenic callus. The embryogenic expression medium was the Knudson's orchid agar (Knudson 1946) medium. Conformity of the plants obtained was checked by comparing their chemotypes with those of the mother plants. PMID:24193517

  13. Evaluation of somaclonal variation during somatic embryogenesis of interior spruce ( Picea glauca engelmannii complex) using culture morphology and isozyme analysis

    Microsoft Academic Search

    P. Ann K. Eastman; Fiona B. Webster; Jack A. Pitel; Dane R. Roberts

    1991-01-01

    Somaclonal variation during interior spruce (Picea glauca engelmannii complex) somatic embryogenesis was evaluated using culture morphology and isozyme analysis. Genotype-specific abscisic acid-dependent developmental profiles and isozyme patterns were similar for subclone and parent line embryogenic cultures and cotyledonary somatic embryos. Extensive analysis of fifteen hundred subclone embryos of one genotype revealed no isozyme pattern variation. Initiation of embryogenic cultures was

  14. Enhancement of somatic embryogenesis in Norway spruce ( Picea abies L.)

    Microsoft Academic Search

    S. Mohan Jain; R. J. Newton; E. J. Soltes

    1988-01-01

    Embryogenic callus developed in 55% of the mature embryo explants of Norway spruce (Picea abies L.) growing on a LP medium minus the amino acids and sugars (except sucrose). This is the highest reported yield of embryogenic callus from mature embryos of P. abies that has ever been reported. Callus induction from either the middle or the end of the

  15. Cold-enhanced somatic embryogenesis in cell suspension cultures of Astragalus adsurgens Pall.: relationship with exogenous calcium during cold pretreatment

    Microsoft Academic Search

    Jian-Ping Luo; Shao-Tong Jiang; Li-Jun Pan

    2003-01-01

    The inter-relationship between exogenous calcium (Ca2+) during cold pretreatment and cold-enhanced somatic embryogenesis was investigated using cell suspension cultures of Astragalus adsurgens Pall. Cell suspension was obtained from embryogenic callus and could be induced to form somatic embryos in the differentiation medium. Suspension cells, after cold-treatment at 8 °C for 2 to 3 wk, displayed an enhanced capacity for somatic

  16. Stress induced acquisition of somatic embryogenesis in common bean Phaseolus vulgaris L.

    PubMed

    Cabrera-Ponce, José Luis; López, Liliana; León-Ramírez, Claudia G; Jofre-Garfias, Alba E; Verver-y-Vargas, Aurora

    2015-03-01

    Common bean Phaseolus vulgaris L. has been shown to be a recalcitrant plant to induce somatic embryogenesis (SE) under in vitro conditions. We used an alternative strategy to induce SE in common bean based upon the use of a cytokinin (BAP) coupled with osmotic stress adaptation instead of SE response that is induced by auxins. Explants derived from zygotic embryos of common bean were subjected to osmotic stress (sucrose 12 % w/v, 0.5 M) in the presence of BAP 10 mg/L and adenine free base 40 mg/L to induce somatic embryos from specific competent cells of the apical meristem and cotyledonary node. Somatic embryos were obtained from the competent cells in a direct response (direct SE). In a secondary response (secondary SE), those somatic embryos formed proembryogenic masses (PEM) that originated/developed into secondary somatic embryos and showed the SE ontogeny. Maturation of somatic embryos was achieved by using different osmolality media and converted to plants. Full-visible light spectrum was necessary to achieve efficient plant regeneration. Long-term recurrent SE was demonstrated by propagation of PEM at early stages of SE. This protocol is currently being applied for stable genetic transformation by means of Agrobacterium tumefaciens and bioballistics as well as for basic biochemical and molecular biology experiments. PMID:25252886

  17. Tobacco arabinogalactan protein NtEPc can promote banana (Musa AAA) somatic embryogenesis.

    PubMed

    Shu, H; Xu, L; Li, Z; Li, J; Jin, Z; Chang, S

    2014-12-01

    Banana is an important tropical fruit worldwide. Parthenocarpy and female sterility made it impossible to improve banana varieties through common hybridization. Genetic transformation for banana improvement is imperative. But the low rate that banana embryogenic callus was induced made the transformation cannot be performed in many laboratories. Finding ways to promote banana somatic embryogenesis is critical for banana genetic transformation. After tobacco arabinogalactan protein gene NtEPc was transformed into Escherichia coli (DE3), the recombinant protein was purified and filter-sterilized. A series of the sterilized protein was added into tissue culture medium. It was found that the number of banana immature male flowers developing embryogenic calli increased significantly in the presence of NtEPc protein compared with the effect of the control medium. Among the treatments, explants cultured on medium containing 10 mg/l of NtEPc protein had the highest chance to develop embryogenic calli. The percentage of lines that developed embryogenic calli on this medium was about 12.5 %. These demonstrated that NtEPc protein can be used to promote banana embryogenesis. This is the first paper that reported that foreign arabinogalactan protein (AGP) could be used to improve banana somatic embryogenesis. PMID:25227688

  18. Metabolic footprinting study of white spruce somatic embryogenesis using NMR spectroscopy.

    PubMed

    Dowlatabadi, Reza; Weljie, Aalim M; Thorpe, Trevor A; Yeung, Edward C; Vogel, Hans J

    2009-05-01

    White spruce is an important commercial species for reforestation. The success in its propagation through somatic embryogenesis is well documented; however the physiological processes involved are poorly understood and remain unoptimized. The variable quality embryos generated in vitro from the same genotype suggest control at the protein and metabolite level. In order to probe metabolic changes, we have conducted a "metabolic footprinting" study, whereby culture media from growing cells was quantitatively analyzed to determine which metabolites were consumed and excreted. Such experiments are advantageous in that there is no need to quench cellular metabolism or extract intracellular metabolites through time-consuming protocols. In this paper we demonstrate the application of the footprinting assay to somatic embryo cells of white spruce (Picea glauca) using 1D (1)H NMR spectroscopy. We have surveyed embryogenesis metabolism in two types of media, maintenance (MN) and maturation (MT). MN medium does not result in shoot apical meristem (SAM) formation, while MT medium induces the necessary changes leading to fully developed somatic embryos. The two types of media were easily distinguished using metabolomics analysis, namely multivariate pattern recognition statistics (orthogonal partial least squares discriminatory analysis). From this analysis, we have identified numerous compounds involved with branched chain amino acid pathways such as valine and isoleucine. These results are explained on the basis of known metabolic pathways implicated in plant and animal developmental processes, and ultimately implicate altered CoA biosynthesis. PMID:19195904

  19. The role of nickel on somatic embryogenesis in Setaria italica L. in vitro

    Microsoft Academic Search

    G. R. Rout; S. Samantaray; P. Das

    1998-01-01

    Nickel (0.13, 0.25, 0.5, 1.0 and 1.5 mg\\/l) increased the efficiency of somatic embryogenesis in leaf base and mesocotyl derived\\u000a calli of Setaria italica. A lower concentration of nickel in the culture media promoted long-term maintenance of embryogenic\\u000a calli that regenerated into plantlets. The plants obtained from embryogenic calli grown on Ni-containing medium showed tolerance\\u000a to nickel. The growth of

  20. Somatic embryogenesis and plant regeneration from immature embryos of five families of Quercus acutissima

    Microsoft Academic Search

    Y. W. Kim; Y. Youn; E. R. Noh; J. C. Kim

    1997-01-01

    Immature embryos of sawtooth oak (Quercus acutissima Carruth.) were obtained from five seed families and cultured on modified Murashige and Skoog nutrient medium containing 1\\u000a g\\/l l-glutamine and 5 mM proline and supplemented with 1.0 mg\\/l indole-3-butyric acid and 1.0 mg\\/l 6-benzylaminopurine. The frequency of somatic embryogenesis\\u000a from immature embryos was a function of the collection date and seed family.

  1. Somatic embryogenesis of tissue cultures of Papaver somniferum and Papaver orientale and its relationship to alkaloid and lipid metabolism

    Microsoft Academic Search

    R. Schuchmann; E. Wellmann

    1983-01-01

    Transfer from complete to 2,4-D free Gamborg's B5-medium efficiently induced somatic embryogenesis in Papaver tissue cultures (P. somniferum and P. orientale). Embryogenesis was preceded by a strong temporary accumulation of triacylglycerols. In both tissue cultures large amounts of sanguinarine type alkaloids were present, which disappeared during regeneration in the P. orientale cultures but persisted in the P. somniferum cultures. In

  2. [Improved protoplast-derived plants of Astragalus adsurgens through somatic embryogenesis].

    PubMed

    Luo, J P; Jia, J F; Gu, Y H; Liu, J

    2000-01-01

    Embryogenic callus was obtained only from hypocotyl explants of Astragalus adsurgens and light inhibited the formation of embryogenic callus. A high yield (1.2 x 10(6)/g F. Wt.) of protoplasts with high viability (over 80%) could be isolated from 10-day-old embryogenic callus. Protoplasts were induced to undergo sustained division and to form cell colonies when cultured in agarose-solidified medium (KMP) containing 1/4 strength of mineral salts and supplemented with 1.5 mg/L 2, 4-D, 0.5 mg/L BA and 0.5 mol/L glucose at a plating density of 1.0 x 10(5)mL, where the plating efficinency was 16.8%. Conditioning medium significantly improved the formation of cell colonies. When protoplast-derived colonies were maintained at 4 degrees C for 2 weeks and subsequently transferred onto medium (MS) with 0.1 mg/L NAA and 1.0 mg/L BA, somatic embryogenesis occurred. Frequency of cell colonies producing somatic embryos reached 70%, and the number of somatic embryos per gram cells was over 200. Cultured on hormone-free half-strength MS medium, somatic embryos developed into healthy plantlets with normal chromosome complement. PMID:10883269

  3. Regeneration of Jatropha curcas through efficient somatic embryogenesis and suspension culture.

    PubMed

    Cai, Lin; Fu, Lin; Ji, Lianghui

    2011-01-01

    .Using immature zygotic embryos as explants, we have developed an efficient method for somatic embryogenesis in three germplasm accessions collected from China, India and Indonesia. Indirect somatic embryogenesis was achieved when endosperm tissue and immature embryos between 0.5-1.0 cm in length were cultured in a medium with 2,4-D, preferably at 5-10 mg/l, followed by a shift to a hormone-free medium supplemented with glutamine and asparagine. Production of secondary embryos was improved by supplementing KNO3, glutamine and asparagine. 2,4-D (0.1-0.2 mg/l). PEG 8000 (5-10%) were essential for maintenance of embryogenic calli in liquid medium. Regeneration of soil-ready plants took as short as 3 months using the suspension cultures. Over 95% of the regenerated trees were able to flower and set seeds with no discernable morphological abnormality. This regeneration method is expected to facilitate the development of more efficient transformation system for Jatropha curcas. PMID:21865864

  4. Somatic embryogenesis and in vitro rosmarinic acid accumulation in Salvia officinalis and S. fruticosa leaf callus cultures

    Microsoft Academic Search

    S. Kintzios; A. Nikolaou; M. Skoula

    1999-01-01

    The effect of explant age, plant growth regulators and culture conditions on somatic embryogenesis and rosmarinic acid production\\u000a from leaf explants of Salvia officinalis and S. fruticosa plants collected in Greece was investigated. Embryogenic callus with numerous spherical somatic embryos could be induced\\u000a on explants derived from both species and cultured for 3 weeks on a Murashige and Skoog (MS)

  5. Somatic embryogenesis and plant regeneration from leaf and petiole explants of Campanula punctata Lam. var. rubriflora Makino

    Microsoft Academic Search

    Iyyakkannu Sivanesan; Mi Young Lim; Byoung Ryong Jeong

    A simple and efficient protocol was developed for somatic embryogenesis from leaf and petiole explants of Campanula punctata Lam. var. rubriflora Makino. Somatic embryos (SE) were obtained with greater frequency from petiole explants than from leaf explants when cultured\\u000a on Murashige and Skoog (MS) medium supplemented with 2.0 mg L?1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L?1 6-benzyladenine (BA). On this medium, a mean

  6. Influence of boric acid on somatic embryogenesis of a cytosterile line of indica rice

    Microsoft Academic Search

    N. A. Sahasrabudhe; Madhumita Nandi; R. A. Bahulikar

    1999-01-01

    The effect of boric acid on somatic embryo induction in rice was investigated using mature seeds of a widely used cytoplasmic\\u000a male sterile line of indica rice IR-58025. Boric acid was added at a concentration of 100.00, 161.29, 241.93, 322.58 and 403.22\\u000a ?M to the embryo induction medium containing basal salts, with 9.84 ?M 2,4-dichlorophenoxyacetic acid. Boric acid was found

  7. First Report of Plant Regeneration via Somatic Embryogenesis from Shoot Apex-derived Callus of Hedychium muluense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants were successfully regenerated via somatic embryogenesis from shoot apex-derived callus of Hedychium muluense R.M. Smith, an important monocotyledonous ornamental ginger plant. Callus was induced on a modified Murashige and Skoog (MS) medium supplemented with 9.05 µM 2-4, D and 4.6µM kinetin. ...

  8. Developmental modulation of tubulin protein and mRNA levels during somatic embryogenesis in cultured carrot cells

    Microsoft Academic Search

    R. J. Cyr; M. M. Bustos; M. J. Guiltinan; D. E. Fosket

    1987-01-01

    The number of cortical microtubules (MTs) increases considerably as cultured carrot (Daucus carota L.) cells initiate and progress through somatic embryogenesis. The basis for this increase in MT number was investigated. A radioimmune assay was used to show that tubulin-protein per cell first decreased as the undifferentiated cells initiated embryonic development, but subsequently increased approximately fivefold between the globular and

  9. Regeneration of Astragalus adsurgens via somatic embryogenesis from cell suspension protoplasts.

    PubMed

    Luo, J P; Jia, J F; Gu, Y H

    1999-12-01

    Protoplasts from 4-day-old embryogenic cell suspension cultures of Astragalus adsurgens, when cultured in KM8P medium which ammonium concentration was reduced to 2.5 mmol/L and supplemented with 0.5 mg/L NAA, 1.0 mg/L 2, 4-D, 0.7 mg/L BA and 0.4 mol/L glucose, underwent cell sustained divisions and formed cell colonies at a frequency of 16%-20%. Preplasmolysis or low temperature treatment of suspension cells prior to enzyme incubation enhanced colony formation. Following proliferation on MS medium containing 1.0 mg/L 2, 4-D and 0.5 mg/L BA, cell colonies were cultured on MS medium containing 0.1 mg/L NAA and 1.0 mg/L BA, where approximately 40% of colonies produced somatic embryos ranging in number from 20 to 40 per colony. No significant decrease was found in the potential of somatic embryogenesis when protoplast colonies were obtained from long-term cell suspensions. On hormone-free 1/2 MS medium, somatic embryos developed into intact plants, which showed normal morphology and stable chromosome number. PMID:12548868

  10. In vitro organogenesis and somatic embryogenesis from leaf explants of Leucosceptrum canum sm.

    PubMed

    Pal, A; Banerjee, A; Dhar, K

    1985-10-01

    Plantlets were obtained from leaf explants of a Labiatae tree - Leucosceptrum canum Sm. using plant tissue culture techniques. Two types of calli proliferated from the leaf explants when grown on different media, one of which was amenable to somatic embryogenesis. Differentiation of the embryoids started from the fourth passage of culture and continued up to the seventh passage. The number of embryoids decreased with the age of the callus. The capacity of such embryoids to form entire plantlets was studied using different nutrient mileux. Embryoids formed plantlets on Murashige and Skoog's (MS) medium fortified with benzylaminopurine plus indolebutyric acid. Organogenesis was observed in shoot-buds derived from explants of in vitro regenerated plantlets on MS basal medium supplemented with benzylaminopurine. Culture regenerated plantlets were transferred to MS medium without sucrose and growth hormones; finally transferred to pots containing sterile vermiculite where they are growing. PMID:24253989

  11. Ammonium-related metabolic changes affect somatic embryogenesis in pumpkin (Cucurbita pepo L.).

    PubMed

    Mihaljevi?, Snježana; Radi?, Sandra; Bauer, Nataša; Gari?, Rade; Mihaljevi?, Branka; Horvat, Gordana; Leljak-Levani?, Dunja; Jelaska, Sibila

    2011-11-01

    Somatic embryogenesis in pumpkin can be induced on auxin-containing medium and also on hormone-free medium containing 1mM ammonium (NH(4)(+)) as the sole source of nitrogen. Growth of NH(4)(+)-induced embryogenic tissue was slow and caused considerable acidification of the culture medium. Small spherical cells with dense cytoplasma formed proembryogenic cell clusters that could not develop into late stage embryos. Buffering of NH(4)(+) medium with 25mM 2-(N-morpholino)-ethane-sulfonic acid enhanced tissue proliferation, but no further differentiation was observed. Later stage embryos developed only after re-supply of nitrogen in form of nitrate or l-glutamine. Effects of nitrogen status and pH of culture media on ammonium assimilation were analyzed by following the activity of glutamine synthetase (GS) in relation to phenylalanine ammonia-lyase (PAL). Increased activity of GS and PAL in NH(4)(+) induced tissue coincided with significantly higher activity of stress-related enzymes superoxide dismutase (SOD) and soluble peroxidase (POD), indicating oxidative stress response of embryogenic tissue to NH(4)(+) as the sole source of nitrogen. In addition, considerable increase was observed in callose accumulation and esterase activity, the early markers of somatic embryogenesis. Activity of stress-related enzymes decreased after the re-supply of nitrate (20mM) or Gln (10mM) in combination with NH(4)(+) (1mM), which subsequently triggered globular embryo development. Together, these results suggest that stress responses, as affected by nitrogen supply, contribute to the regulation of embryogenic competence in pumpkin. PMID:21807439

  12. Protocol for in vitro somatic embryogenesis and regeneration of rice (Oryza sativa L.).

    PubMed

    Verma, Dipti; Joshi, Rohit; Shukla, Alok; Kumar, Pramod

    2011-12-01

    Development of highly efficient and reproducible plant regeneration system has tremendous potential to provide improved technology to assist in genetic transformation of indica rice cultivars for their further exploitation in selection. For the development of a highly reproducible regeneration system through somatic embryogenesis, mature embryos of highly popular rice cultivars i.e., Govind (for rainfed areas), Pusa Basmati-1 (aromatic basmati) and Jaya (for irrigated areas) were used. Optimum callus formation (%) to MS medium supplemented with 2, 4-D was obtained at 12.0 microM in Govind, 14.0 microM in Jaya and 15.0 microM in Pusa Basmati-1. All the cultivars showed good proliferation on MS medium without hormone. In Govind, highest embryogenic response was observed in MS medium supplemented with 2, 4-D (0.4 microM) + kinetin (0.4 microM), while in Pusa Basmati-1 with 2, 4-D (0.4 microM) + kinetin (2.0 microM) and in Jaya on hormone-free MS medium. Excellent embryo regeneration in Govind was observed on MS medium supplemented with low concentrations (1.1 microM) of BAP or hormone-free MS medium, while in Pusa Basmati-1 and Jaya embryogenesis was observed on MS medium supplemented with higher concentration of BAP (2.2 microM). Similarly, maximum plantlets with proliferated roots were observed in Govind on hormone-free MS medium, while in Pusa Basmati-1 and Jaya on MS medium supplemented with high concentration of NAA (4.0 microM). Developed plantlets were further successfully acclimatized and grown under pot culture up to maturity. Further the yield potential of in vitro developed plants was accessed at par to the direct seeded one under pot culture. Present, protocol standardizes somatic embryogenesis and efficient regeneration of agronomically important, high yielding and diverse indica rice cultivars which can be utilized as an efficient tool for molecular studies and genetic transformation in future. PMID:22403871

  13. Developmental Plasticity of Glandular Trichomes into Somatic Embryogenesis in Tilia amurensis

    PubMed Central

    Kim, T. D.; Lee, B. S.; Kim, T. S.; Choi, Y. E.

    2007-01-01

    Background and Aims In Tilia amurensis, two types of trichomes (hairy and glandular) develop from epidermal surfaces of cotyledons and hypocotyls of zygotic embryos soon after germination. Here, it is demonstrated that glandular trichome initials develop directly into somatic embryos when treated in vitro with 2,4-dichlorophenoxyacetic acid (2,4-D). Methods Zygotic embryos of Tilia amurensis were cultured on Murashige and Skoog medium with 3 % sucrose and various concentrations (0, 2·2, 4·4 and 8·8 µm) of 2,4-D. Morphological development of trichomes and somatic embryos was analysed by scanning electron microscope and light microscope after histological sectioning. Key Results In zygotic embryos cultured on medium with 4·4 µm 2,4-D, formation of hairy trichomes was completely suppressed but formation of glandular trichome initials increased. That some filamentous trichome initials developed directly into somatic embryos was confirmed by histological and scanning electron microscope observation. When explants with different stages of trichome initials (two-, four- and eight-celled filamentous and fully mature trichomes) were temporally pre-treated with 4·4 µm 2,4-D for 24 h and transferred into hormone-free medium, two-celled and four-celled filamentous trichome initials were the effective stage of trichomes for somatic embryo induction. Conclusions It is suggested that early developing filamentous trichome initials have developmental plasticity and that with 2,4-D treatment these trichome initials develop directly into somatic embryos. PMID:17565972

  14. Interactions of ancymidol with sucrose and ?-naphthaleneacetic acid in promoting asparagus (Asparagus officinalis L.) somatic embryogenesis

    Microsoft Academic Search

    B. Li; D. J. Wolyn

    1997-01-01

    Interactions of varying ancymidol concentrations with those of ?-naphthaleneacetic acid (NAA) or sucrose in embryo induction medium were related to the production and development of asparagus\\u000a (Asparagus officinalis L.) somatic embryos, and to the ability of these embryos to germinate. A significant sucrose×ancymidol interaction was observed\\u000a only for the production of bipolar embryos; 4% sucrose with 0.75 mg l–1 ancymidol

  15. Somatic embryogenesis and vegetative cutting capacity are under distinct genetic control in Coffea canephora Pierre.

    PubMed

    Priyono; Florin, Bruno; Rigoreau, Michel; Ducos, Jean-Paul; Sumirat, Ucu; Mawardi, Surip; Lambot, Charles; Broun, Pierre; Pétiard, Vincent; Wahyudi, Teguh; Crouzillat, Dominique

    2010-04-01

    The purpose of the study was to evaluate the possible genetic effect on vegetative propagation of Coffea canephora. Diversity for somatic embryogenesis (SE) ability was observed not only among two groups of C. canephora Pierre (Congolese and Guinean), but also within these different genetic groups. The results therefore showed that, under given experimental conditions, SE ability is depending on genotype. Furthermore the detection of quantitative trait loci (QTLs) controlling the SE and cutting abilities of C. canephora was performed on a large number of clones including accessions from a core collection, three parental clones and their segregating progenies. On the one hand we detected eight QTLs determining SE. Six positive QTLs for SE ability, whatever the criteria used to quantify this ability, were localized on one single chromosome region of the consensus genetic map. Two negative QTLs for SE ability (frequency of micro calli without somatic embryo) were detected on another linkage group. Deep analysis of the six QTLs detected for SE ability came to the conclusion that they can be assimilated to one single QTL explaining 8.6-12.2% of the observed variation. On the other hand, two QTLs for average length of roots and length of the longest sprouts of cuttings were detected in two linkage groups. These QTLs detected for cutting ability are explaining 12-27% of the observed variation. These observations led to conclude that SE and cutting abilities of C. canephora Pierre appeared to be genetic dependent but through independent mechanisms. PMID:20145933

  16. Somatic embryogenesis and plant regeneration from immature embryos of saw palmetto, an important landscape and medicinal plant

    Microsoft Academic Search

    M. Gallo-Meagher; J. Green

    2002-01-01

    Somatic embryogenesis and plant regeneration from immature zygotic embryos was achieved for saw palmetto (Serenoa repens (Bartr.) Small). Embryos, isolated from immature fruit of native-grown plants, were cultured on Murashige and Skoog medium plus 0.15% (w\\/v) activated charcoal and supplemented with 452 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 14.7 µM N6-(2-isopentenyl)adenine (2iP). Clusters of somatic embryos developed from all immature zygotic

  17. Initiation of somatic embryogenesis in white spruce ( Picea glauca ): genetic control, culture treatment effects, and implications for tree breeding

    Microsoft Academic Search

    Y. S. Park; S. E. Pond; J. M. Bonga

    1993-01-01

    The degree of genetic control and the effects of cultural treatments on somatic embryogenesis (SE) in white spruce were investigated with material derived from six-parent diallel crosses, including reciprocals. Thirty zygotic embryos from both immature and mature cones of each family were cultured in media with either 2,4-D or Picloram immediately after the collection of cones and after 2 months

  18. Application of somatic embryogenesis in high-value clonal forestry: Deployment, genetic control, and stability of cryopreserved clones

    Microsoft Academic Search

    Y. S. Park; J. D. Barrett; J. M. Bonga

    1998-01-01

    Summary  The most important advantage of cloning conifers by somatic embryogenesis (SE) is that the embryogenic tissue can be cryopreserved\\u000a without changing its genetic make-up and without loss of juvenility. This offers an opportunity to develop high-value clonal\\u000a varieties by defrosting and repropagating cryopreserved clones after genetic testing has shown which clones are the best performers.\\u000a In the current absence of

  19. Influence of media and growth regulators on somatic embryogenesis and plant regeneration for production of primary triticales

    Microsoft Academic Search

    A. S. T. Immonen

    1996-01-01

    Basal media and plant growth regulators were tested for the promotion of somatic embryogenesis from immature wheat-rye hybrid embryos. Influence of growth regulators and chilling on plant regeneration were tested on two media. A medium containing four amino acids-glutamine, arginine, glycine and aspartic acid-as the nitrogen source, promoted the production of, on average, twice as much embryogenic callus as the

  20. Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling

    PubMed Central

    Fayos, Oreto; Vallés, María P.; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M.

    2015-01-01

    The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2–3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20–23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 ?M APM in liquid medium. However, the application of 25 ?M in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis efficiency.

  1. Glutathione-S-Transferase is Detected During Somatic Embryogenesis in Chicory

    PubMed Central

    Galland, Rachel; Blervacq, Anne-Sophie; Blassiau, Christelle; Smagghe, Benoît; Decottignies, Jean-Pierre

    2007-01-01

    Glutathione S-tranferases (GSTs) are a heterogeneous family of proteins, which perform diverse pivotal catalytic and non-enzymatic functions during plant development and in plant stress responses. Previous studies have shown that a GST activity (EC 2.5.1.18) is closely linked with the precocious phases of somatic embryogenesis in leaf tissues of an interspecific chicory hybrid (Cichorium intybus L. var. sativa × C. endivia L. var. latifolia). In order to learn more about the involvement of this enzyme in this process, in situ-hybridization as well as immunolocalization were performed in parallel. GST-mRNAs and proteins were colocalized in small veins, particularly in young protoxylem cell walls. During cell reactivation, the in situ and protein signals became less intense and were associated with chloroplasts. The GST-mRNAs and corresponding proteins were not always colocalized in the same tissues. While high amounts of transcripts could be detected in multicellular embryos, the proteins were not well labeled. Our results indicated that GSTs belong to a complex anti-oxidant mechanism within the cell, and also at the cell wall level. GSTs presence in reactivated cell and multicellular embryos is discussed in relation to redox cell status. PMID:19516999

  2. Characterization of VvSERK1 , VvSERK2 , VvSERK3 and VvL1L genes and their expression during somatic embryogenesis of grapevine ( Vitis vinifera L.)

    Microsoft Academic Search

    Paul Schellenbaum; Alban Jacques; Pascale Maillot; Christophe Bertsch; Flore Mazet; Sibylle Farine; Bernard Walter

    2008-01-01

    Little is known about the genes expressed during grapevine somatic embryogenesis. Both groups of Somatic Embryogenesis Receptor Kinase (SERK) and Leafy Cotyledon (LEC and L1L) genes seem to play key roles during somatic embryogenesis in various plant species. Therefore, we identified and analysed\\u000a the sequences of VvSERK and VvL1L (Leafy cotyledon1-Like) genes. The deduced amino acid sequences of VvSERK1, VvSERK2

  3. Influence of plant growth regulators, carbon sources and iron on the cyclic secondary somatic embryogenesis and plant regeneration of transgenic cherry rootstock `Colt' ( Prunus avium × P. pseudocerasus )

    Microsoft Academic Search

    Patricia Gutièrrez pesce; Eddo Rugini

    2004-01-01

    The frequency of long-term secondary somatic embryogenesis and shoot meristem development from embryogenic masses of the cherry rootstock `Colt' ( Prunus avium × P. pseudocerasus), differentiated from transgenic roots containing the T-DNA of Agrobacterium rhizogenes, has opened the way for genetic improvement by biotechnological techniques. Whole plants were produced by stimulating shoot meristem development from somatic embryos. The combination of

  4. Alterations in the transcriptome of soybean in response to enhanced somatic embryogenesis promoted by orthologs of Agamous-like15 and Agamous-like18.

    PubMed

    Zheng, Qiaolin; Perry, Sharyn E

    2014-03-01

    Somatic embryogenesis (SE) is a poorly understood process during which competent cells respond to inducing conditions, allowing the development of somatic embryos. It is important for the regeneration of transgenic plants, including for soybean (Glycine max). We report here that constitutive expression of soybean orthologs of the Arabidopsis (Arabidopsis thaliana) MADS box genes Agamous-like15 (GmAGL15) and GmAGL18 increased embryogenic competence of explants from these transgenic soybean plants. To understand how GmAGL15 promotes SE, expression studies were performed. Particular genes of interest involved in embryogenesis (abscisic acid-insensitive3 and FUSCA3) were found to be directly up-regulated by GmAGL15 by using a combination of quantitative reverse transcription-polymerase chain reaction and chromatin immunoprecipitation. To look more broadly at changes in gene expression in response to GmAGL15, we assessed the transcriptome using the Affymetrix Soybean Genome Array. Interestingly, the gene expression profile of 35Spro:GmAGL15 explants (0 d in culture) was found to resemble nontransgenic tissue that had been induced for SE by being placed on induction medium for 3 d, possibly explaining the more rapid SE development observed on 35Spro:GmAGL15 tissue. In particular, transcripts from genes related to the stress response showed increased transcript accumulation in explants from 35Spro:GmAGL15 tissue. These same genes also showed increased transcript accumulation in response to culturing nontransgenic soybean explants on the medium used to induce SE. Overexpression of GmAGL15 may enhance SE by making the tissue more competent to respond to 2,4-dichlorophenoxyacetic acid induction by differential regulation of genes such as those involved in the stress response, resulting in more rapid and prolific SE. PMID:24481137

  5. Small RNA and degradome sequencing reveal complex miRNA regulation during cotton somatic embryogenesis

    PubMed Central

    Yang, Xiyan; Wang, Lichen; Zhang, Xianlong

    2013-01-01

    MicroRNAs (miRNAs) are endogenous non-coding ~21 nucleotide RNAs that regulate gene expression at the transcriptional and post-transcriptional levels in plants and animals. They play an important role in development, abiotic stress, and pathogen responses. miRNAs with their targets have been widely studied in model plants, but limited knowledge is available on the small RNA population of cotton (Gossypium hirsutum)—an important economic crop, and global identification of related targets through degradome sequencing has not been developed previously. In this study, small RNAs and their targets were identified during cotton somatic embryogenesis (SE) through high-throughput small RNA and degradome sequencing, comparing seedling hypocotyl and embryogenic callus (EC) of G. hirsutum YZ1. A total of 36 known miRNA families were found to be differentially expressed, of which 19 miRNA families were represented by 29 precursors. Twenty-five novel miRNAs were identified. A total of 234 transcripts in EC and 322 transcripts in control (CK) were found to be the targets of 23 and 30 known miRNA families, respectively, and 16 transcripts were targeted by eight novel miRNAs. Interestingly, four trans-acting small interfering RNAs (tas3-siRNAs) were also found in degradome libraries, three of which perfectly matched their precursors. Several targets were further validated via RNA ligase-mediated rapid amplification of 5’ cDNA ends (RLM 5’-RACE). The profiling of the miRNAs and their target genes provides new information on the miRNAs network during cotton SE. PMID:23382553

  6. Lodgepole pine: the first evidence of seed-based somatic embryogenesis and the expression of embryogenesis marker genes in shoot bud cultures of adult trees.

    PubMed

    Park, So-Young; Klimaszewska, Krystyna; Park, Ji-Young; Mansfield, Shawn D

    2010-11-01

    Of the various alternatives for cloning elite conifers, somatic embryogenesis (SE) appears to be the best option. In recent years, significant areas of lodgepole pine (Pinus contorta) forest have been devastated by the mountain pine beetle (MPB) in Western Canada. In an attempt to establish an SE propagation system for MPB-resistant lodgepole pine, several families displaying varying levels of resistance were selected for experimentation involving shoot bud and immature seed explants. In bud cultures, eight embryogenic lines were induced from 2 of 15 genotypes following various treatments. Genotype had an important influence on embryogenic culture initiation, and this effect was consistent over time. These lines were identified by microscopic observation and genetic markers. Despite the abundance of early somatic embryos, the cultures have yet to develop into mature embryos. In contrast, immature zygotic embryos (ZEs) cultured from megagametophytes initiated SE at an early dominance stage via nodule-type callus in 1 of 10 genotypes. As part of the study, putative embryogenesis-specific genes, WOX2 (WUSCHELL homeobox 2) and HAP3A, were analyzed in cultures of both shoot bud explants and ZEs. On the basis of these analyses, we postulate that PcHAP3A was expressed mainly in callus and may be involved in cell division, whereas WOX2 was expressed mainly in embryonal mass (EM)-like tissues. The findings from this study, based on molecular assessment, suggest that the cell lines derived from bud cultures were truly EM. Moreover, these experimental observations suggest that PcWOX2 could be used as an early genetic marker to discriminate embryogenic cultures from callus. PMID:20935320

  7. Propagation of Gentiana macrophylla (Pall) from hairy root explants via indirect somatic embryogenesis and gentiopicroside content in obtained plants

    Microsoft Academic Search

    Hai Jun Wu; Xin Xin Wang; Yan Li; Dong Guang Zhang; Bing Zhang; Xin Yu Wang

    An effective protocol for plant regeneration from hairy root (HR) via indirect somatic embryogenesis was established in medicinal\\u000a plant Gentiana macrophylla, a perennial herb in Gentianaceae. On the MS medium containing 0.5–2.5 mg l?1 2,4-dichlorophenoxyacetic acid (2,4-D) or 2,4-D plus benzylaminopurine (BAP), all the HR explants produced embryogenic calli\\u000a (ECs). After transfer to plant growth regulator (PGR)-free MS medium, up to 94%

  8. Quantitation of gibberellins and the metabolism of [ 3 H]gibberellin A 1 during somatic embryogenesis in carrot and anise cell cultures

    Microsoft Academic Search

    Masana Noma; Jochen Huber; Dieter Ernst; Richard P. Pharis

    1982-01-01

    In a carrot (Daucus carota L.) cell line lacking the ability to undergo somatic embryogenasis, and in carrot and anise (Pimpinella anisum L.) cell lines in which embryogenesis could be regulated by presence or absence of 2,4-dichlorophen-oxyacetic acid (2,4-D), in the medium (+2,4-D=no embryogenesis,-2,4-D=embryo differentiation and development), the levels of endogenous gibberellin(s) (GA) were determined by the dwarfrice bioassay, and

  9. Stage and tissue-specific modulation of ten conserved miRNAs and their targets during somatic embryogenesis of Valencia sweet orange

    Microsoft Academic Search

    Xiao-Meng Wu; Mei-Ya Liu; Xiao-Xia Ge; Qiang Xu; Wen-Wu Guo

    2011-01-01

    Somatic embryogenesis (SE) is a remarkable process of plant somatic cells developing into an embryo capable of forming a complete\\u000a plant. MiRNAs play important roles in plant development by regulating expression of their target genes, but its function in\\u000a SE has rarely been studied. Herein, ten conserved miRNAs with critical functions in plant development are detected by stem-loop\\u000a qRT-PCR in

  10. A rapid system for micropropagation of Swertia chirata Buch-Ham. ex Wall.: an endangered medicinal herb via direct somatic embryogenesis

    Microsoft Academic Search

    K. Balaraju; S. Saravanan; P. Agastian; S. Ignacimuthu

    2011-01-01

    An improved method of direct somatic embryogenesis (SE) was developed in Swertia chirata for the first time using leaves and roots of in vitro-grown young seedlings. In the present study, 2,4-dichlorophenoxyacetic\\u000a acid (2,4-D) was assessed individually and in combination with other auxins, as well as with cytokinin for its effectiveness\\u000a to induce somatic embryos. Leaf explants with abaxial side in

  11. Developmental localization and the role of hydroxyproline rich glycoproteins during somatic embryogenesis of banana (Musa spp. AAA)

    PubMed Central

    2011-01-01

    Background Hydroxyproline rich glycoproteins (HRGPs) are implicated to have a role in many aspects of plant growth and development but there is limited knowledge about their localization and function during somatic embryogenesis of higher plants. In this study, the localization and function of hydroxyproline rich glycoproteins in embryogenic cells (ECs) and somatic embryos of banana were investigated by using immunobloting and immunocytochemistry with monoclonal JIM11 and JIM20 antibodies as well as by treatment with 3,4-dehydro-L-proline (3,4-DHP, an inhibitor of extensin biosynthesis), and by immunomodulation with the JIM11 antibody. Results Immunofluorescence labelling of JIM11 and JIM20 hydroxyproline rich glycoprotein epitopes was relatively weak in non-embryogenic cells (NECs), mainly on the edge of small cell aggregates. On the other hand, hydroxyproline rich glycoprotein epitopes were found to be enriched in early embryogenic cells as well as in various developmental stages of somatic embryos. Embryogenic cells (ECs), proembryos and globular embryos showed strong labelling of hydroxyproline rich glycoprotein epitopes, especially in their cell walls and outer surface layer, so-called extracellular matrix (ECM). This hydroxyproline rich glycoprotein signal at embryo surfaces decreased and/or fully disappeared during later developmental stages (e.g. pear-shaped and cotyledonary stages) of embryos. In these later developmental embryogenic stages, however, new prominent hydroxyproline rich glycoprotein labelling appeared in tri-cellular junctions among parenchymatic cells inside these embryos. Overall immunofluorescence labelling of late stage embryos with JIM20 antibody was weaker than that of JIM11. Western blot analysis supported the above immunolocalization data. The treatment with 3,4-DHP inhibited the development of embryogenic cells and decreased the rate of embryo germination. Embryo-like structures, which developed after 3,4-DHP treatment showed aberrant non-compact epidermis with discontinuous ECM at the outer surface as well as much less immunolabelling with the JIM11 antibody. This treatment also decreased the plant regeneration capacity in embryogenic banana cultures. Finally, immunomodulation of surface hydroxyproline rich glycoproteins by co-culture of embryos with the JIM11 antibody resulted in a much lower germination capacity of these embryos. Conclusions These results suggest that hydroxyproline rich glycoproteins play an important developmental role, especially in the process of regeneration and germination of embryos during plant regeneration via somatic embryogenesis. Proper content and localization of hydroxyproline rich glycoproteins seem to be essential for the formation and regeneration of banana somatic embryos. PMID:21349190

  12. The effect of auxins, time exposure to auxin and genotypes on somatic embryogenesis from mature embryos of wheat

    Microsoft Academic Search

    Mikhail Filippov; Dmitry Miroshnichenko; Darya Vernikovskaya; Sergey Dolgov

    2006-01-01

    The effects of different factors on the embryogenesis and plant regeneration from mature embryos of Russian spring and winter\\u000a genotypes were studied. Embryogenic callus induction was achieved on MS medium supplemented with different concentrations\\u000a of 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) or Dicamba (3,6-dichloro-o-anisic acid). Although all auxins were able to induce callus from explants with high frequency (98–100%), Dicamba

  13. The Arabidopsis Somatic Embryogenesis Receptor Kinase 1 Gene Is Expressed in Developing Ovules and Embryos and Enhances Embryogenic Competence in Culture1

    PubMed Central

    Hecht, Valérie; Vielle-Calzada, Jean-Philippe; Hartog, Marijke V.; Schmidt, Ed D.L.; Boutilier, Kim; Grossniklaus, Ueli; de Vries, Sacco C.

    2001-01-01

    We report here the isolation of the Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (AtSERK1) gene and we demonstrate its role during establishment of somatic embryogenesis in culture. The AtSERK1 gene is highly expressed during embryogenic cell formation in culture and during early embryogenesis. The AtSERK1 gene is first expressed in planta during megasporogenesis in the nucleus of developing ovules, in the functional megaspore, and in all cells of the embryo sac up to fertilization. After fertilization, AtSERK1 expression is seen in all cells of the developing embryo until the heart stage. After this stage, AtSERK1 expression is no longer detectable in the embryo or in any part of the developing seed. Low expression is detected in adult vascular tissue. Ectopic expression of the full-length AtSERK1 cDNA under the control of the cauliflower mosaic virus 35S promoter did not result in any altered plant phenotype. However, seedlings that overexpressed the AtSERK1 mRNA exhibited a 3- to 4-fold increase in efficiency for initiation of somatic embryogenesis. Thus, an increased AtSERK1 level is sufficient to confer embryogenic competence in culture. PMID:11706164

  14. Induction of Canonical Wnt Signaling by Alsterpaullone Is Sufficient for Oral Tissue Fate During Regeneration and Embryogenesis in Nematostella vectensis

    PubMed Central

    Trevino, Michael; Stefanik, Derek J.; Rodriguez, Richard; Harmon, Shane; Burton, Patrick M.

    2013-01-01

    Although regeneration is widespread among metazoa, the molecular mechanisms have been studied in only a handful of taxa. Of these taxa, fewer still are amenable to studies of embryogenesis. Our understanding of the evolution of regeneration, and its relation to embryogenesis, therefore remains limited. Using ?-catenin as a marker, we investigated the role of canonical Wnt signaling during both regeneration and embryogenesis in the cnidarian Nematostella vectensis. The canonical Wnt signaling pathway is known to play a conserved role in primary axis patterning in triploblasts. Induction of Wnt signaling with alsterpaullone results in ectopic oral tissue during both regeneration and embryogenesis by specifically upregulating ?-catenin expression, as measured by qRTPCR. Our data indicate that canonical Wnt signaling is sufficient for oral patterning during Nematostella regeneration and embryogenesis. These data also contribute to a growing body of literature indicating a conserved role for patterning mechanisms across various developmental modes of metazoans. PMID:22052821

  15. Characterization of recurrent somatic embryogenesis of alfalfa on auxin-free medium

    Microsoft Academic Search

    Wayne A. Parrott; Matthew A. Bailey

    1993-01-01

    Callus cultures from 300 genotypes of alfalfa (Medicago sativa L.) were initiated from leaf, petiole, and internode explants placed on Blaydes medium containing 10.74 µM a-naphthaleneacetic acid, 11.42 µM indole-3-acetic acid, and 9.29 µM kinetin. Five genotypes produced somatic embryos. Upon transfer of these embryos to growth regulator-free Murashige and Skoog medium with B5 vitamins, new somatic embryos repeatedly formed

  16. Regeneration of transgenic papaya plants via somatic embryogenesis induced by Agrobacterium rhizogenes

    Microsoft Academic Search

    José Luis Cabrera-Ponce; Ariadne Vegas-Garcia; Luis Herrera-Estrella

    1996-01-01

    AnAgrobacterium rhizogenes-mediated procedure for transformation of papaya (Carica papaya) was developed. Transgenic plants were obtained from somatic embryos that spontaneously formed at the base of transformed\\u000a roots, induced from leaf discs infected withA. rhizogenes. Transformation was monitored by autonomous growth of roots and somatic embryos, resistance to kanamycin, ?-glucuronidase\\u000a activity (GUS), and Southern hybridization analysis. Over one-third of the infected

  17. Somatic embryogenesis and plant regeneration from cell suspension cultures of Cucumis sativus L

    Microsoft Academic Search

    Paula P. Chee; David M. Tricoli

    1988-01-01

    A procedure for the regeneration of whole cucumber plants (Cucumis sativus L. cv. Poinsett 76) by embryogenesis from cell suspension cultures is described. Embryogenic callus was initiated from the primary leaves of 14–17 day old plants. Suspension cultures of embryogenic cells were grown in liquid Murashige and Skoog basal medium containing 5 uM 2,4,5-trichlorophenoxyacetic acid and 4 uM 6-benzylaminopurine. Suspension

  18. Endogenous Abscisic Acid and Indole-3-Acetic Acid and Somatic Embryogenesis in Cultured Leaf Explants of Pennisetum purpureum Schum. : Effects in Vivo and in Vitro of Glyphosate, Fluridone, and Paclobutrazol.

    PubMed

    Rajasekaran, K; Hein, M B; Vasil, I K

    1987-05-01

    Effects of application in vivo of glyphosate, fluridone, and paclobutrazol to glasshouse-grown donor plants of Pennisetum purpureum Schum. on endogenous levels of abscisic acid (ABA) and indole-3-acetic acid (IAA) in young leaves and on somatic embryogenesis in cultured leaf explants were studied. Treatment of plants with glyphosate (100 milligrams per liter) resulted in elevated levels of endogenous ABA and IAA in young leaves. In contrast, paclobutrazol (50% active ingredient; 200 milligrams per liter) did not alter the endogenous levels of ABA and IAA. Fluridone (100 milligrams per liter) markedly inhibited synthesis of ABA and leaf explants from fluridone-treated plants lost the capacity for somatic embryogenesis. Explants from glyphosate- or paclobutrazol-treated plants did not show any reduction in embryogenic capacity when compared with untreated control plants. Glyphosate and fluridone were also incorporated into the culture media at various concentrations (0 to 20 milligrams per liter) to study their effects in vitro on somatic embryogenesis in leaf explants from untreated, field-grown plants. Glyphosate was inhibitory to somatic embryogenesis but only at concentrations above 5 milligrams per liter. Fluridone inhibited somatic embryogenesis at all concentrations tested. Inhibition of somatic embryogenesis by fluridone, by either in vivo or in vitro application, could be overcome partially by (+/-)-ABA added to the culture medium. Exogenous application of (+/-)-ABA enhanced somatic embryogenesis and reduced the formation of nonembryogenic callus. Application of IAA or gibberellic acid (GA(3); >5 milligrams per liter) was inhibitory to somatic embryogenesis. These results indicate that endogenous ABA is one of the important factors controlling the embryogenic capacity of leaf explants in Napier grass. PMID:16665403

  19. Somatic embryogenesis from cell suspension and protoplast cultures of Capsella bursa-pastoris (L.) Medic

    Microsoft Academic Search

    A. C. Bonfils; S. C. Gleddie; J. A. Webb; W. A. Keller

    1992-01-01

    Summary  Rapidly growing cell suspension cultures of shepherd’s purse (Capsella bursa-pastoris L. Medic.) were established from leaf-derived calli. These suspensions remained unorganized in the presence of 2,4-D, but\\u000a underwent extensive root organogenesis in a growth regulator-free liquid medium. Attempts to induce direct embryogenesis in\\u000a liquid cultures were unsuccessful, but numerous embryos were obtained from cells plated onto growth-regulator-free solid medium.\\u000a These

  20. Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland

    E-print Network

    Chee, Peng W.

    -naphthalene acetic acid (NAA)-based treatments, S15 g.05 NAA and EMMS2, as compared to the 2,4-dichlorophenoxyacetic ­ indole-3-acetic acid; BA ­ benzyladenine; 2,4-DD ­ 2,4-dichlorophenoxyacetic acid; MS ­ Murashige acid (2,4-DD)-based culture medium, EMMS4. Inclusion of 0.5 mg l)1 Putrescine improved somatic embryo

  1. Clustering of Microarray Data Reveals Transcript Patterns Associated with Somatic Embryogenesis in Soybean1[w

    PubMed Central

    Thibaud-Nissen, Françoise; Shealy, Robin T.; Khanna, Anupama; Vodkin, Lila O.

    2003-01-01

    Globular somatic embryos can be induced from immature cotyledons of soybean (Glycine max L. Merr. cv Jack) placed on high levels of the auxin 2,4-dichlorophenoxyacetic acid (2,4-D). Somatic embryos develop from the adaxial side of the cotyledon, whereas the abaxial side evolves into a callus. Using a 9,280-cDNA clone array, we have compared steady-state RNA from the adaxial side from which embryos develop and from the abaxial callus at five time points over the course of the 4 weeks necessary for the development of globular embryos. In a second set of experiments, we have profiled the expression of each clone in the adaxial side during the same period. A total of 495 genes differentially expressed in at least one of these experiments were grouped according to the similarity of their expression profiles using a nonhierarchical clustering algorithm. Our results indicate that the appearance of somatic embryos is preceded by dedifferentiation of the cotyledon during the first 2 weeks on auxin. Changes in mRNA abundance of genes characteristic of oxidative stress and genes indicative of cell division in the adaxial side of the cotyledons suggest that the arrangement of the new cells into organized structures might depend on a genetically controlled balance between cell proliferation and cell death. Our data also suggest that the formation of somatic globular embryos is accompanied by the transcription of storage proteins and the synthesis of gibberellic acid. PMID:12746518

  2. Plant regeneration in Chlorophytum borivilianum Sant. et Fernand. from embryogenic callus and cell suspension culture and assessment of genetic fidelity of plants derived through somatic embryogenesis.

    PubMed

    Rizvi, Mohd Zahid; Kukreja, Arun Kumar; Bisht, Narendra Singh

    2012-07-01

    Efficient in vitro propagation of medicinally important endangered plant C. borivilianum has been achieved through somatic embryogenesis. Solid embryogenic medium [Murashige and Skoog medium containing 1.79 mM NH4NO3, 10.72 mM KNO3, 1.13 ?M 2,4-dichlorophenoxyacetic acid, 7.38 ?M 2-isopentenyladenine and 0.76 mM proline] supplemented with polyethylene glycol and sucrose (3 % each), exhibited 1.88-fold increase in embryo maturation compared to embryogenic medium containing 3 % sucrose. Liquid embryogenic medium supported better somatic embryo production and maturation. Highest total (79) and mature (cotyledonary stage) somatic embryos (38) as well as highest germination (57.5 %) was observed at inoculum density of 0.4 g/40 ml of liquid medium. 5.86 pH level exhibited optimal growth, maturation and germination of somatic embryos. Random amplified polymorphic DNA (RAPD) analysis of C. borivilianum plants regenerated through somatic embryogenesis revealed that they were genetically similar to the mother plant. The protocol established in the present study can be used for rapid mass multiplication of C. borivilianum in bioreactor employing liquid medium. PMID:23814440

  3. Do stress-related phytohormones, abscisic acid and jasmonic acid play a role in the regulation of Medicago sativa L. somatic embryogenesis?

    Microsoft Academic Search

    Izabela Rudu?; Elmar W. Weiler; Ewa K?pczy?ska

    2009-01-01

    This study examined the role of endogenous abscisic acid (ABA) and jasmonic acid (JA) in indirect somatic embryogenesis of\\u000a Medicago sativa L. A multiplex GC-MS\\/MS technique allowed quantitative single-run analyses of ABA, JA, 12-oxophytodienoic acid (OPDA) and\\u000a indole-3-acetic acid (IAA). The preparation of initial explants led to a strong accumulation of ABA, JA and OPDA but not of\\u000a IAA. Substantially

  4. Stepwise decrease of 2,4-D and addition of BA in subculture medium stimulated shoot regeneration and somatic embryogenesis in buffalograss

    Microsoft Academic Search

    Shui-Zhang Fei; Terry Riordan; Paul Read

    2002-01-01

    Plant regeneration of buffalograss `Texoka' was achieved through both somatic embryogenesis and organogenesis by culturing immature male inflorescences collected from field-grown plants. Three passages of subculture for calluses derived from male `Texoka' on medium containing 2.25, 4.5, or 9 µM 2,4-D combined with either 0.44 µM or 1.32 µM BA led to shoot formation via organogenesis. Higher concentrations of 2,4-D

  5. Evidence for new nuclear and mitochondrial genome organizations among high-frequency somatic embryogenesis-derived plants of allotetraploid Coffea arabica L. (Rubiaceae)

    Microsoft Academic Search

    V. Rani; K. P. Singh; B. Shiran; S. Nandy; S. Goel; R. M. Devarumath; H. L. Sreenath; S. N. Raina

    2000-01-01

    The most important commercial species of coffee, Coffea arabica, which produces 73% of the world's coffee crop and almost all of the coffee in Latin America, is the only tetraploid (allotetraploid,\\u000a 2n=4x=44) species known in the genus. High-frequency somatic embryogenesis, plant regeneration and plant recovery were achieved\\u000a from leaf explants of a mature, elite plant of C. arabica cv. Cauvery

  6. Callus production, somatic embryogenesis and plant regeneration of Lycium barbarum root explants

    Microsoft Academic Search

    Z. Hu; Y. Hu; H. H. Gao; X. Q. Guan; D. H. Zhuang

    2008-01-01

    A new micropropagation system for Lycium barbarum (L.) was developed using root explants as starting material. Callus can be produced from root explants on Murashige and Skoog\\u000a (MS) medium containing 0.2 mg dm?3 2,4-dichlorophenoxyacetic acid. After three subcultures on the same medium, callus was then transferred onto the MS medium\\u000a supplemented with 500 mg dm?3 lactalbumin hydrolysate to induce somatic

  7. Rapid propagation of lemongrass ( Cymbopogon flexuosus (Nees) Wats.) through somatic embryogenesis in vitro

    Microsoft Academic Search

    S. Nayak; B. K. Debata; S. Sahoo

    1996-01-01

    Somatic embryos induced from callus cultures of lemongrass [Cymbopogon flexuosus (Nees) Wats.] on Murashige and Skoog medium supplemented with 5 mg\\/l of 2,4-D, 0.1 mg\\/l of NAA and 0.5 mg\\/l of Kn developed into plantlets when plated on a medium supplemented with 3 mg\\/l of BA, 1 mg\\/l of GA3 and 0.1 mg\\/l of NAA. The regeneration potential of callus

  8. High Frequency Plant Regeneration from Astragalus melilotoides hypocotyl and stem explants via somatic embryogenesis and organogenesis

    Microsoft Academic Search

    Sui-Wen Hou; Jing-Fen Jia

    2004-01-01

    An efficient and reproducible procedure is established for the plant regeneration from hypocotyl explants and hypocotyl-or stem-derived calli in Astragalus melilotoides. High frequency somatic embryo formation (98.3%) occurred direct on hypocotyls on Murashige and Skoog (MS) medium supplemented with 2.69 µM NAA and 4.44 µM BA within 5 weeks. Three types of calli were induced from the hypocotyl and stem

  9. Enhanced somatic embryogenesis in Selinum candolii DC. under a mineral oil overlay

    Microsoft Academic Search

    Jaideep Mathur

    1991-01-01

    Cell suspension cultures of Selinum candolii DC. obtained on liquid Murashige & Skoog's medium supplemented with 4.52 µM 2,4-D and 1.16 µM kinetin when plated on solid medium devoid of 2,4-D proliferated into a callus and subsequently produced 15–20 somatic embryos within 60 days. However, when the plated cells were overlaid with mineral oil, a decrease in callus formation coupled

  10. Direct somatic embryogenesis and plantlet regeneration from cotyledonary leaves of safflower

    Microsoft Academic Search

    A. K. A. Mandal; A. K. Chatterji; S. Dutta Gupta

    1995-01-01

    Somatic embryos were induced directly on adaxial surface of cotyledonary leaves within 8–10 days of culture on Murashige and Skoog medium containing 5.37 to 10.74 µM 1 — napthaleneacetic acid and 2.22 µM benzyl adenine. Germinated embryos with shoot axes developed into complete plants after transfer onto half stength Murashige and Skoog medium containing 1.07 µM 1 — napthaleneacetic acid.

  11. Thidiazuron stimulates shoot organogenesis and somatic embryogenesis in white ash (Fraxinus americana L.)

    Microsoft Academic Search

    Sharon Bates; John E. Preece; Nadia E. Navarrete; J. W. Sambeek; Gerald R. Gaffney

    1992-01-01

    Immature and mature nonstratified seeds of white ash (Fraxinus americana L.) were dissected transversely and 2\\/3 of each seed was placed onto agar-solidified Murashige and Skoog medium. Adventitious buds, shoots, and somatic embryos formed on callus, cotyledons, and hypocotyls of the resulting seedlings. Shoot organogenesis was induced on explants cultured on medium with 10 µM thidiazuron but not on explants

  12. Improved culture conditions for somatic embryogenesis from Asparagus officinalis L. using an aseptic ventilative filter

    Microsoft Academic Search

    Takeo Saito; Shuji Nishizawa; Shigeo Nishimura

    1991-01-01

    Calli were induced from the crown of seedlings or lateral bud of young spears of Asparagus officinalis L. on Linsmaier and Skoog's (LS) solid-medium supplemented with 5 µ M 2,4-dichlorophenoxyacetic acid (2,4-D). Embryogenic callus was selected from induced calli and proliferated in LS liquid medium supplemented with 5 µ M 2,4-D. Non-vitrified somatic embryos were formed and efficiently developed into

  13. Pretreatments, conditioned medium and co-culture increase the incidence of somatic embryogenesis of different Cichorium species

    PubMed Central

    Couillerot, Jean-Paul; Windels, David; Vazquez, Franck; Michalski, Jean-Claude; Hilbert, Jean-Louis; Blervacq, Anne-Sophie

    2012-01-01

    Somatic embryogenesis (SE) in Cichorium involves dedifferentiation and redifferentiation of single cells and can be induced by specific in vitro culture conditions. We have tested the effect of various treatments on the incidence of SE (ISE) of an interspecific embryogenic hybrid (C. endivia x C. intybus) and of different commercial chicories (C. endivia and C. intybus) that are typically recalcitrant to SE in standard culture conditions. We found that the ISE of the hybrid is significantly increased by pretreatment of tissues by submersion in solutions of glycerol, abscisic acid, spermine, putrescine or of combinations of these compounds. Interestingly, the most efficient of these pretreatments also had an unexpectedly high effect on the ISE of the C. intybus cultivars. The ISE of the hybrid and of the commercial chicories were increased when explants were co-cultured with highly embryogenic chicory explants or when they were cultured in conditioned medium. These observations established that unidentified SE-promoting factors are released in the culture medium. HPLC analyses of secreted Arabino-Galactan Proteins (AGPs), which are known to stimulate SE, did not allow identifying a fraction containing differentially abundant AGP candidates. However, pointing to their role in promoting SE, we found that the hybrid had a drastically higher ISE when amino sugars and L-Proline, the putative precursors of secreted AGPs, were both added to the medium. PMID:22301978

  14. Genetic instability in calamondin ( Citrus madurensis Lour.) plants derived from somatic embryogenesis induced by diphenylurea derivatives

    Microsoft Academic Search

    Mirko Siragusa; Angela Carra; Lidia Salvia; Anna Maria Puglia; Fabio De Pasquale; Francesco Carimi

    2007-01-01

    Somatic embryos were regenerated in vitro from calamondin style–stigma explants cultured in the presence of N\\u000a 6-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N?-benzothiazol-6-ylurea (PBU) and N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 ?M) were\\u000a able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF)\\u000a conditions.

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

    PubMed

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

    2010-07-01

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

  16. A Novel In Vitro Protocol for Inducing Direct Somatic Embryogenesis in Phalaenopsis aphrodite without Taking Explants

    PubMed Central

    Chen, Jen-Tsung

    2014-01-01

    An alternative in vitro protocol for embryo induction directly from intact living seedlings of Phalaenopsis aphrodite subspecies formosana was established in this study. Without the supplementation of plant growth regulators (PGRs), no embryos were obtained from all the seedlings when cultured on the solid medium. In contrast, embryos formed from the seedlings on the 2-layer medium and the 2-step culture system without the use of PGRs. It was found that the age of the seedlings affected embryo induction. The 2-month-old seedlings typically had higher embryogenic responses when compared with the 4-month-old seedlings in the 2-layer medium or 2-step system. For the 2-month-old seedlings, 1?mg/L TDZ resulted in the highest number of embryos at the distal site of the shoot. However, on the leaves' surface, 0.5?mg/L TDZ induced the highest number of embryos. When the 2-month-old seedlings were cultured using the 2-step method at 1?mg/L of TDZ, the highest embryogenic response was obtained, with an average of 44 embryos formed on each seedling. These adventitious embryos were able to convert into plantlets in a PGR-free 1/2 MS medium, and the plantlets had normal morphology and growth. PMID:24963505

  17. Distribution and changes of reserve materials in cotyledon cells of Panax ginseng related to direct somatic embryogenesis and germination

    Microsoft Academic Search

    Y. E. Choi; D. C. Yang; H. S. Kim; K. T. Choi

    1997-01-01

    Cotyledon explants from zygotic embryos of Panax ginseng produced somatic embryos on Murashige and Skoog basal medium without growth regulators. Somatic embryos developed directly\\u000a from epidermal cells at the cotyledon base. Somatic embryos were always formed from the side of the cotyledon opposite to\\u000a the one attached to the medium surface regardless of cotyledon orientation. The frequency of somatic embryo

  18. Abscisic acid induction of cloned cotton late embryogenesis-abundant (Lea) mRNAs

    Microsoft Academic Search

    Glenn A. Galau; D. Wayne Hughes; Leon Dure

    1986-01-01

    Earlier studies found that cotton (Gossypium hirsutum L.) cotyledons contain several mRNAs which are more abundant during late embryogenesis than in mid-embryogenesis or early germination. They are here termed ‘Late embryogenesis-abundant’ mRNAs, encoded by Lea loci. Complementary DNA clones for 18 such mRNA sequences, defined at a hybridization criterion of Tm-15°C, were identified in a mature embryo cDNA library by

  19. Effect of 1-Aminocyclopropane-1-carboxylic acid and aminoethoxyvinylglycine on ethylene emanation and somatic embryogenesis from orchardgrass leaf cultures

    Microsoft Academic Search

    D. D. Songstad; P. D. Petracek; C. E. Sams; B. V. Conger

    1989-01-01

    Ethylene emanation rates were assessed from leaf tissues of an embryogenic seed plant (Cycle 0) and regeneration cycle plants selected for enhanced embryogenesis (Cycles I, II and IV). In all experiments, ethylene was assessed from the basal 1 cm portion of the innermost leaf. Ethylene emanation was five-fold higher in Cycle II and Cycle IV plants than in Cycle 0

  20. Effect of 1-Aminocyclopropane-1-carboxylic acid and aminoethoxyvinylglycine on ethylene emanation and somatic embryogenesis from orchardgrass leaf cultures.

    PubMed

    Songstad, D D; Petracek, P D; Sams, C E; Conger, B V

    1989-03-01

    Ethylene emanation rates were assessed from leaf tissues of an embryogenic seed plant (Cycle 0) and regeneration cycle plants selected for enhanced embryogenesis (Cycles I, II and IV). In all experiments, ethylene was assessed from the basal 1 cm portion of the innermost leaf. Ethylene emanation was five-fold higher in Cycle II and Cycle IV plants than in Cycle 0 and nonembryogenic (NE) seed plants. After two days culture on Schenk and Hildebrandt medium containing 30 ?M dicamba (SH-30), ethylene emanation from Cycle 0 and Cycle II leaf sections increased by 55-fold. Culture of leaf explants for 30 days on SH-30 containing 1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) reduced the embryogenic response by 99%. Treatment of leaf explants with 1 mM aminoethoxyvinylglycine (AVG) reduced ethylene emanation but did not affect embryogenesis. The data indicate that ethylene mediated by ACC may hinder the embryogenic response from orchardgrass leaf cultures. PMID:24240460

  1. Comparative Analysis Reveals Dynamic Changes in miRNAs and Their Targets and Expression during Somatic Embryogenesis in Longan (Dimocarpus longan Lour.)

    PubMed Central

    Lin, Yuling; Lai, Zhongxiong

    2013-01-01

    Somatic embryogenesis (SE), which resembles zygotic embryogenesis, is an essential component of the process of plant cell differentiation and embryo development. Although microRNAs (miRNAs) are important regulators of many plant develop- mental processes, their roles in SE have not been thoroughly investigated. In this study, we used deep-sequencing, computational, and qPCR methods to identify, profile, and describe conserved and novel miRNAs involved in longan (Dimocarpus longan) SE. A total of 643 conserved and 29 novel miRNAs (including star strands) from more than 169 miRNA families were identified in longan embryogenic tissue using Solexa sequencing. By combining computational and degradome sequencing approaches, we were able to predict 2063 targets of 272 miRNAs and verify 862 targets of 181 miRNAs. Target annotation revealed that the putative targets were involved in a broad variety of biological processes, including plant metabolism, signal transduction, and stimulus response. Analysis of stage- and tissue-specific expressions of 20 conserved and 4 novel miRNAs indicated their possible roles in longan SE. These miRNAs were dlo-miR156 family members and dlo-miR166c* associated with early embryonic culture developmental stages; dlo-miR26, dlo-miR160a, and families dlo-miR159, dlo-miR390, and dlo-miR398b related to heart-shaped and torpedo- shaped embryo formation; dlo-miR4a, dlo-miR24, dlo-miR167a, dlo-miR168a*, dlo-miR397a, dlo-miR398b.1, dlo-miR398b.2, dlo-miR808 and dlo-miR5077 involved in cotyledonary embryonic development; and dlo-miR17 and dlo-miR2089*-1 that have regulatory roles during longan SE. In addition, dlo-miR167a, dlo-miR808, and dlo-miR5077 may be required for mature embryo formation. This study is the first reported investigation of longan SE involving large-scale cloning, characterization, and expression profiling of miRNAs and their targets. The reported results contribute to our knowledge of somatic embryo miRNAs and provide insights into miRNA biogenesis and expression in plant somatic embryo development. PMID:23593197

  2. Genetic variability analyses of the somatic embryogenesis induction process in Olea spp . using nuclear microsatellites

    Microsoft Academic Search

    Tina Lopes; Ana Capelo; Gina Brito; João Loureiro; Conceição Santos

    2009-01-01

    The crop species Olea europaea L. (olive tree) is of great economic importance in the Mediterranean region. Hence, many efforts have been done in the last\\u000a decades to propagate this commercially valuable species by in vitro methods. On the other hand, the lesser known Olea maderensis (Lowe) Rivas Mart. & Del Arco which is a native species of the Madeira

  3. Plant regeneration of Carica papaya L. through somatic embryogenesis in response to light quality, gelling agent and phloridzin

    Microsoft Academic Search

    Azucena Ascencio-Cabral; Humberto Gutiérrez-Pulido; Benjamín Rodríguez-Garay; Antonia Gutiérrez-Mora

    2008-01-01

    Difficulties to develop an easy and reproducible protocol to get healthy and well formed plants from somatic embryos of papaya (Carica papaya L.) had included low germination, callus production at the base of the embryo radicle and the occurrence of hyperhydric plantlets among others, and by consequence unsuccessful transfer to the field. With the aim of improving a propagation method,

  4. Conifer WOX -related homeodomain transcription factors, developmental consideration and expression dynamic of WOX2 during Picea abies somatic embryogenesis

    Microsoft Academic Search

    Joakim Palovaara; Inger Hakman

    2008-01-01

    In angiosperms, the WOX family of transcription factors has important functions in meristem regulation and in control of the\\u000a partitioning of developing embryos into functional domains. In this study, a putative WOX2 homologous gene was isolated from Picea abies, and its expression pattern during somatic embryo development was followed using real-time quantitative reverse transcription\\u000a polymerase chain reaction (qRT-PCR). We used

  5. Improved somatic embryogenesis in wheat by partial simulation of the in-ovulo oxygen, growth-regulator and desiccation environments

    Microsoft Academic Search

    J. G. Carman

    1988-01-01

    The effects of O2, growth-regulators and desiccation on callus growth and somatic embryo (embryoid) development were investigated in cultures of immature embryos of two lines of Triticum aestivum L. Callus and embryoid formation were induced on media that contained N6-furfurylamin-opurine (kinetin) and either 2,4-dichlorophenoxyacetic acid or 3,6-dichloro-o-anisic acid, either with or without abscisic acid (ABA). Cultures containing differentiated embryoids were

  6. Comparative study of somatic embryogenesis from immature and mature embryos and organogenesis from leaf-base of Triticale

    Microsoft Academic Search

    Vikrant; A. Rashid

    2001-01-01

    Immature and mature zygotic embryos of hexaploid, Triticale var. DT-46 formed an embryogenic callus, with subsequent somatic embryo formation upon subculture to MS (Murashige and Skoog, 1962) or N6 (Chu et al., 1975) nutrient medium supplemented with various concentrations (9.0–22.5 µM) of 2,4-dichlorophenoxyacetic acid (2,4-D). Of the two types of explants, embryogenic tissue from immature embryos responded at a higher

  7. Factors influencing somatic embryogenesis, regeneration, and Agrobacterium-mediated transformation of cassava (Manihot esculenta Crantz) cultivar TME14

    PubMed Central

    Nyaboga, Evans N.; Njiru, Joshua M.; Tripathi, Leena

    2015-01-01

    Routine production of large numbers of transgenic plants is required to fully exploit advances in cassava biotechnology and support development of improved germplasm for deployment to farmers. This article describes an improved, high-efficiency transformation protocol for recalcitrant cassava cultivar TME14 preferred in Africa. Factors that favor production of friable embryogenic calli (FEC) were found to be use of DKW medium, crushing of organized embryogenic structures (OES) through 1–2 mm sized metal wire mesh, washing of crushed OES tissues and short exposure of tyrosine to somatic embryos; and transformation efficiency was enhanced by use of low Agrobacterium density during co-cultivation, co-centrifugation of FEC with Agrobacterium, germination of paramomycin resistant somatic embryos on medium containing BAP with gradual increase in concentration and variations of the frequency of subculture of cotyledonary-stage embryos on shoot elongation medium. By applying the optimized parameters, FEC were produced for cassava cultivar TME14 and transformed using Agrobacterium strain LBA4404 harboring the binary vector pCAMBIA2301. About 70–80 independent transgenic lines per ml settled cell volume (SCV) of FEC were regenerated on selective medium. Histochemical GUS assays confirmed the expression of gusA gene in transformed calli, somatic embryos and transgenic plants. The presence and integration of the gusA gene were confirmed by PCR and Southern blot analysis, respectively. RT-PCR analysis of transgenic plants confirmed the expression of gusA gene. This protocol demonstrates significantly enhanced transformation efficiency over existing cassava transformation protocols and could become a powerful tool for functional genomics and transferring new traits into cassava. PMID:26113851

  8. Somatic embryogenesis in sugarcane ( Saccharum officinarum L.) I. The morphology and physiology of callus formation and the ontogeny of somatic embryos

    Microsoft Academic Search

    Wai-Jane Ho; Indra K. Vasil

    1983-01-01

    Summary Embryogenic callus was induced on segments of young leaves of sugarcane (Saccharum officinarum L.) cultured on Murashige and Skoog's medium supplemented with 0.5–3.0 mg\\/2,4-D, 5% coconut milk and 3–8% sucrose. The fourth and fifth leaves, especially their midrib and sheath regions within 5 cm from the leaf base, were most suitable for the induction of embryogenic callus. Many embryoids

  9. Somatic embryogenesis and rhizogenesis of tissue cultures of two genotypes of Papaver somniferum: relationships to alkaloids production.

    PubMed

    Laurain-Mattar, D; Gillet-Manceau, F; Buchon, L; Nabha, S; Fliniaux, M A; Jacquin-Bubreuil, A

    1999-03-01

    PAPAVER SOMNIFERUM L. tissue cultures, issued from various explants (cotyledons, hypocotyls, roots) derived from plantlets belonging to two genotypes, were established on LS solid medium containing growth regulators (NAA, Kin) in various combinations. Hypocotyls and roots were found to be interesting explants to obtain cellular development. Many roots developed on calli growing on a medium containing NAA (1 mg/l) + Kin (0.1 mg/l) for the PS genotype while somatic proembryos redifferentiated on calli issued from PS 1639 genotype. The same growth substance combination was the most favourable for the production of morphinan alkaloids and papaverine: up to 10 x 10 (-3)% DW in roots redifferentiated from PS calluses. PMID:17260250

  10. Direct somatic embryogenesis and plant regeneration from immature embryos of hybrid sunflower ( Helianthus annuus L.) on a high sucrose-containing medium

    Microsoft Academic Search

    John J. Finer

    1987-01-01

    Somatic embryos of sunflower (Helianthus annuus) were obtained by placing immature zygotic embryos on a high sucrose (12%) containing medium. The somatic embryos were first observed 6 days after culture and a callus intermediate was not formed. Histological examination revealed the classical stages of embryo development. The somatic embryos proliferated directly from the surface of the zygotic embryos and germinated

  11. Somatic Embryogenesis in the Cycadales

    Microsoft Academic Search

    Richard E. Litz; Victor M. Chavez; Pamela A. Moon

    \\u000a The cycads (Fig. 1) constitute remnant species of an ancient class of gymnosperms, the cycadophytes, that evolved from the\\u000a free-sporing progymnosperms, which also gave rise to the coniferophytes. According to Gifford & Foster (1989), the cycadophytes\\u000a have included 3 orders of plants, the extinct Cycadeoidales and Pteridospermales (seed ferns), that are known only from the\\u000a fossil record, and the Cycadales,

  12. Changes in nucleus, nucleolus and cell size accompanying somatic embryogenesis of Theobroma cacao L. II. Relation between basic protein content and size of nucleus, nucleolus and cell.

    PubMed

    Kononowicz, H; Janick, J

    1988-01-01

    Embryo formation from callus of Theobroma cacao L. was associated with the changes in relationship between nuclear, nucleolar and cell sizes and the content of basic proteins (FG-FCF-stained). Together with the increase in nuclear size of callus and proembryo cells the increase in the amount of nuclear basic proteins was found. In the callus cells the increase in nucleolar protein content exceeded that in nucleolus size, which led to the rise in basic protein concentration in the nucleolus. However, in the early stage of embryogenesis the increase in protein content was not so marked as that in callus, which indicated that embryogenesis involved a decrease in concentration of nucleolar basic proteins. Differences between callus and proembryo cells were also observed in the concentration of cytoplasmic proteins. The increase in size of callus cells was the same as the increasing amount of cytoplasmic proteins. In proembryos a significant increase in cell size was accompanied by only slight changes in cytoplasmic proteins. The stimulation of embryogenesis by 2,4-D resulted in an increase of nuclear concentration of basic proteins in proembryos. The intensification of embryogenesis involved the decrease of the concentration of nucleolar proteins together with the increase in concentration of basic cytoplasmic proteins. PMID:2464508

  13. Protocols for Callus and Somatic Embryo Initiation for Hibiscus sabdariffa L. (Malvaceae): Influence of Explant Type, Sugar, and Plant Growth Regulators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A significant work on callus induction and somatic embryogenesis was realized for Hibiscus sabdariffa. Two genotypes (Hibiscus sabdariffa and Hibiscus sabdariffa var. altissima) two sugars (sucrose and glucose) and three concentrations (1 %, 2%, 3%) of each sugar, 3 explant types (root, hypocotyl, c...

  14. Camalexin induction in intertribal somatic hybrids between Camelina sativa and rapid-cycling Brassica oleracea

    Microsoft Academic Search

    M. A. Sigareva; E. D. Earle

    1999-01-01

    Camelina sativa, a wild relative of Brassica crops, is virtually immune to blackspot disease caused by Alternaria brassicicola. Intertribal somatic hybrids were produced between C. sativa and rapid-cycling Brassica oleracea as a step toward the transfer of resistance to this disease into Brassica vegetable crops. The plants recovered were confirmed as somatic hybrids by flow cytometry and RAPD analysis. All

  15. Characterization of three heat-shock-protein genes and their developmental regulation during somatic embryogenesis in white spruce [ Picea glauca (Moench) Voss

    Microsoft Academic Search

    Jin-Zhuo Dong; David I. Dunstan

    1996-01-01

    Three cDNAs (PgEMB22, 27 and 29) predicted to encode low-molecular-weight (LMW) heat-shock proteins (HSPs) were cloned and characterized from white spruce [Picea glauca (Moench) Voss] somatic embryo tissues by differentially screening a cotyledonary embryo cDNA library. Clone PgEMB22 is predicted to encode a putative mitochondria-localized LMW HSP, and PgEMB27 and 29 are predicted to encode different cytoplasmic class II LMW

  16. Induction of embryogenicTriticum aestivum L. calli. II. Quantification of organic addenda and other culture variable effects

    Microsoft Academic Search

    John G. Carman; Nancy E. Jefferson; William F. Campbell

    1988-01-01

    Nine experiments were conducted to determine effects of various culture medium addenda on induction of embryogenic calli from immature embryos of a responsiveTriticum aestivum L. genotype (PCYT 10). Effects were quatified by counting somatic embryos (embryoids) per callus. Optimal auxin concentrations to induce and maintain somatic embryogenesis were 3.62 µM 2,4-dichlorophenoxyacetic acid (2,4-D) or 9.05 µM 3,6-dichloro-o-anisic acid (dicamba). In

  17. Induction conditions for somatic and microspore-derived structures and detection of haploid status by isozyme analysis in anther culture of caraway ( Carum carvi L.)

    Microsoft Academic Search

    Iva Smýkalová; Ji?í Horá?ek; Michaela Kubošiová; Prokop Šmirous; Aleš Soukup; Nikol Gasmanová; Miroslav Griga

    Plant regeneration was obtained from cultured anthers and hypocotyl segments of caraway (Carum carvi L.). Microspore- and somatic tissue-derived embryos were compared by observation of the regeneration process under identical\\u000a induction conditions. Fluorescent microscopy with DAPI staining showed initiation of cell divisions and formation of embryogenic\\u000a callus and somatic embryos from anther sacs, with production of embryos of both microspore

  18. Modulation of somatic embryogenesis in early and late-stage embryos of wheat (Triticum aestivum L.) under the influence of (±)-abscisic acid and its analogs

    Microsoft Academic Search

    Javed A. Qureshi; Kutty K. Kartha; Suzanne R. Abrams; Lee Steinhauer

    1989-01-01

    Zygotic embryos from ten spring wheat (Triticum aestivum L.) genotypes were tested for embryogenic callus induction in the presence or absence of externally supplied (±)-abscisic acid (ABA) and two of its analogs, methyl abscisate and methyl epoxy-beta-ionylideneacetate. (±)-ABA and its analogs suppressed precocious germination of cultured late-stage embryos and promoted embryogenic callus induction. A significantly greater number of plants was

  19. Histological and transcript analyses of intact somatic embryos in an elite maize (Zea mays L.) inbred line Y423.

    PubMed

    Liu, Beibei; Su, Shengzhong; Wu, Ying; Li, Ying; Shan, Xiaohui; Li, Shipeng; Liu, Hongkui; Dong, Haixiao; Ding, Meiqi; Han, Junyou; Yuan, Yaping

    2015-07-01

    Intact somatic embryos were obtained from an elite maize inbred line Y423, bred in our laboratory. Using 13-day immature embryos after self-pollination as explants, and after 4-5 times subculture, a large number of somatic embryos were detected on the surface of the embryonic calli on the medium. The intact somatic embryos were transferred into the differential medium, where the plantlets regenerated with shoots and roots forming simultaneously. Histological analysis and scanning electron micrographs confirmed the different developmental stages of somatic embryogenesis, including globular-shaped embryo, pear-shaped embryo, scutiform embryo, and mature embryo. cDNA-amplified fragment length polymorphism (cDNA-AFLP) was used for comparative transcript profiling between embryogenic and non-embryogenic calli of a new elite maize inbred line Y423 during somatic embryogenesis. Differentially expressed genes were cloned and sequenced. Gene Ontology analysis of 117 candidate genes indicated their involvement in cellular component, biological process and molecular function. Nine of the candidate genes were selected. The changes in their expression levels during embryo induction and regeneration were analyzed in detail using quantitative real-time PCR. Two full-length cDNA sequences, encoding ZmSUF4 (suppressor of fir 4-like protein) and ZmDRP3A (dynamin-related protein), were cloned successfully from intact somatic embryos of the elite inbred maize line Y423. Here, a procedure for maize plant regeneration from somatic embryos is described. Additionally, the possible roles of some of these genes during the somatic embryogenesis has been discussed. This study is a systematic analysis of the cellular and molecular mechanism during the formation of intact somatic embryos in maize. PMID:25931320

  20. Induction of pluripotent stem cells from autopsy donor-derived somatic cells

    Microsoft Academic Search

    Brooke E. Hjelm; Jon B. Rosenberg; Szabolcs Szelinger; Lucia I. Sue; Thomas G. Beach; Matthew J. Huentelman; David W. Craig

    2011-01-01

    Human induced pluripotent stem cells (iPSCs) have become an intriguing approach for neurological disease modeling, because neural lineage-specific cell types that retain the donors’ complex genetics can be established in vitro. The statistical power of these iPSC-based models, however, is dependent on accurate diagnoses of the somatic cell donors; unfortunately, many neurodegenerative diseases are commonly misdiagnosed in live human subjects.

  1. SOMATIC CROSSING OVER IN GLYCINE MAX (L.) MERRILL: EFFECT OF SOME INHIBITORS OF DNA SYNTHESIS ON THE INDUCTION OF SOMATIC CROSSING OVER AND POINT MUTATIONS

    Microsoft Academic Search

    B. K. VIG

    1973-01-01

    Glycine max (soybean) is the only known higher plant with a definitely established occurrence of somatic crossing over. This material lends itself to the analysis of somatic crossing over, gross chromosomal aberrations and mu- tations, all of which may be induced by the same treatment of the mutagen given to seeds. This is made possible because gene Y,, for chlorophyll

  2. Pine embryogenesis

    PubMed Central

    Sutela, Suvi; Tillman-Sutela, Eila; Kauppi, Anneli; Jokela, Anne; Sarjala, Tytti; Häggman, Hely

    2009-01-01

    In plants, programmed cell death (PCD) is an important mechanism that controls normal growth and development as well as many defence responses. At present, research on PCD in different plant species is actively carried out due to the possibilities offered by modern methods in molecular biology and the increasing amount of genome data. The pine seed provides a favourable model for PCD because it represents an interesting inheritance of seed tissues as well as an anatomically well-described embryogenesis during which several tissues die via morphologically different PCD processes. PMID:19826239

  3. Technological Overview of iPS Induction from Human Adult Somatic Cells

    PubMed Central

    Bayart, Emilie; Cohen-Haguenauer, Odile

    2013-01-01

    The unlimited proliferation capacity of embryonic stem cells (ESCs) combined with their pluripotent differentiation potential in various lineages raised great interest in both the scientific community and the public at large with hope for future prospects of regenerative medicine. However, since ESCs are derived from human embryos, their use is associated with significant ethical issues preventing broad studies and therapeutic applications. To get around this bottleneck, Takahashi and Yamanaka have recently achieved the conversion of adult somatic cells into ES-like cells via the forced expression of four transcription factors: Oct3/4, Sox2, Klf4 and c-Myc. This first demonstration attracted public attention and opened a new field of stem cells research with both cognitive – such as disease modeling - and therapeutic prospects. This pioneer work just received the 2012 Nobel Prize in Physiology or Medicine. Many methods have been reported since 2006, for the generation of induced pluripotent stem (iPS) cells. Most strategies currently under use are based on gene delivery via gamma-retroviral or lentiviral vectors; some experiments have also been successful using plasmids or transposons-based systems and few with adenovirus. However, most experiments involve integration in the host cell genome with an identified risk for insertional mutagenesis and oncogenic transformation. To circumvent such risks which are deemed incompatible with therapeutic prospects, significant progress has been made with transgene-free reprogramming methods based on e.g.: sendaï virus or direct mRNA or protein delivery to achieve conversion of adult cells into iPS. In this review we aim to cover current knowledge relating to both delivery systems and combinations of inducing factors including chemicals which are used to generate human iPS cells. Finally, genetic instability resulting from the reprogramming process is also being considered as a safety bottleneck for future clinical translation and stem cell-therapy prospects based on iPS. PMID:23320476

  4. INDUCTION, MAINTENANCE AND PRESERVATION OF EMBRYOGENIC COMPETENCE OF GENTIANA CRUCIATA L. CULTURES

    Microsoft Academic Search

    ANNA MIKUèA; AGNIESZKA FIUK; JAN J. RYBCZYNSKI

    2005-01-01

    The paper describes structural and ultrastructural changes in primary explants, induction of embryogenesis, somatic embryo development, and four protocols for cryopreservation of cell suspensions. The changes during tissue culture of hypocotyl and cotyledon explants from 10-day-old seedlings and fragments of leaf explant of Gentiana cruciata L. were studied. Seedling explants were cultured on MS medium supplemented with 1.0 mg\\/l dicamba

  5. Changes in nucleus, nucleolus and cell size accompanying somatic embryogenesis of Theobroma cacao L. I. Relationship between DNA and total protein content and size of nucleus, nucleolus and cell.

    PubMed

    Kononowicz, H; Janick, J

    1988-01-01

    There was a linear relation between an increase in DNA content and size of nuclei, nucleoli and cells in callus and proembryos (Theobroma cacao L.). In callus the increase of DNA content was accompanied by proportional increase in nuclear size whereas in proembryos the increase in nuclear size did not match the increasing amount of DNA. The stimulation of embryogenesis by 10(-2) mg/l 2,4-D was associated with increase in nuclear and nucleolar size and with decrease in cell sizes. Inhibition of embryogenesis by 1.0 mg/l 2,4-D+10% coconut water did not change nuclear size, but increased cell size in relation to the control. The process of embryo formation was accompanied by changes in relationship between nuclear, nucleolar and cell size and the total (DNFB-stained) proteins content. In callus as well as in proembryo the increase in total protein content in nucleus was not equivalent to the increasing sizes of nuclei which leads to the decrease in nuclear protein concentration. Similar situation was observed for nucleoli. Differences were found in the concentration of cytoplasmic proteins between the callus and proembryo cells. The stimulation of embryogenesis by low concentration of 2,4-D resulted in decrease in concentration of total proteins in nuclei and nucleoli and the increase in cytoplasm. PMID:3220146

  6. Characterization of leafy cotyledon1-like during embryogenesis in Theobroma cacao L

    Microsoft Academic Search

    Laurence Alemanno; Martine Devic; Nicolas Niemenak; Christine Sanier; Jocelyne Guilleminot; Mariannick Rio; Jean-Luc Verdeil; Pascal Montoro

    2008-01-01

    Theobroma cacao L., an economically important crop for developing countries, can be experimentally propagated by somatic embryogenesis. Because\\u000a of their potential roles in embryogenesis, a gene candidate strategy was initiated to find gene homologues of the members\\u000a of the leafy cotyledon family of transcription factors. A homologue of the leafy cotyledon1-like gene, that encodes the HAP 3 subunit of the

  7. Systems Biology of Embryogenesis

    PubMed Central

    Edelman, Lucas B.; Chandrasekaran, Sriram; Price, Nathan D.

    2010-01-01

    The development of a complete organism from a single cell involves extraordinarily complex orchestration of biological processes that vary intricately across space and time. Systems biology seeks to describe how all elements of a biological system interact in order to understand, model, and ultimately predict aspects of emergent biological processes. Embryogenesis represents an extraordinary opportunity – and challenge – for the application of systems biology. Systems approaches have already been used successfully to study various aspects of development, from complex intracellular networks to 4D models of organogenesis. Going forward, great advancements and discoveries can be expected from systems approaches applied to embryogenesis and developmental biology. PMID:20003850

  8. Induction of microspore embryogenesis in cultured anthers of hordeum vulgare. The effects of ammonium nitrate, glutamine and asparagine as nitrogen sources

    Microsoft Academic Search

    Finn Lok Olsen

    1987-01-01

    Improvement of the yield of green plants was obtained by decreasing the concentration of ammonium nitrate in the culture medium\\u000a and using glutamine as a nontoxic nitrogen source. Embryoids developed directly from the microspores on such media, and frequently\\u000a green plants were obtained by germination of the embryoids on the induction medium, whereas formation of calli was greatly\\u000a reduced.\\u000a \\u000a Ficoll

  9. Somatic embryos from callus of Salix viminalis L. L. Grnroos, S. von Arnold T. Ericsson

    E-print Network

    Paris-Sud XI, Université de

    Somatic embryos from callus of Salix viminalis L. L. Grönroos, S. von Arnold T. Ericsson Department is in preparation and will be pub- lished elsewhere. Somatic embryogenesis in pistil callus of basket willow (Salix of embryogenic cal- lus obtained from Salix in the future, the embryogenic callus and the other callus types

  10. Cyanogenesis in somatic embryos and plantlets of cassava (Manihot esculenta Crantz)

    E-print Network

    Yeoh, Hock Hin

    Cyanogenesis in somatic embryos and plantlets of cassava (Manihot esculenta Crantz) Tessy Joseph cyclic somatic embryogenesis and plant regeneration for the cassava variety PRC 60a. Linamarin content. This system would be useful for investigating cyanogenesis in cassava. # 1999 Society of Chemical Industry

  11. In vitro plant regeneration and ethylmethanesulphonate (EMS) uptake in somatic embryos of date palm (Phoenix dactylifera L.)

    Microsoft Academic Search

    M. S. Omar; F. J. Novak

    1990-01-01

    The effect of the auxins dicamba (3,6-dichloro-2-methoxybenzoic acid) and picloram (4-amino-3,5,6-trichloropicolinic acid) on callus growth and embryogenesis in Phoenix dactylifera L. was investigated. Maximum callus fresh weight was obtained in nutrient medium enriched with 200 µm picloram. Somatic embryogenesis and subsequent plant regeneration was achieved following transfer of such calli to hormone-free medium. Germination of the somatic embryos was influenced

  12. Genetic variation in somatic embryogenesis of Rosa Hybrida L. 

    E-print Network

    Burrell, Anna Mildred

    2004-09-30

    ), caffeic acid (1 mg l-1), coconut water (10% v/v), sucrose (20 g l-1), and gel-rite (2.4 g l-1). The pH was adjusted to 5.5. The medium was autoclaved for 20 minutes at 121 ° C 15 psi. Heat labile KM-8P (1X) vitamins were filter-sterilized then added...), glycine (2.0 mg l-1), 2,4-D (2, 4-dichlorophenoxyacetic acid, 2.0 mg l- 1), zeatin (1.5 mg l-1), MS vitamins (Murashige, 1962), carbohydrate treatment and gel- rite (2.4 g l-1). The pH of the each treatment was adjusted to 5.6. The MS medium consisted...

  13. Somatic Embryogenesis From Mature Seed Cultures of Pistacia atlantica

    Microsoft Academic Search

    Ahmet ONAY

    2000-01-01

    Embryogenic mass was produced from kernels of mature fruits of Pistacia atlantica cultured in liquid Murashige and Skoog media, supplemented with 100 mg\\/l casein hydrolysate, 100 mg\\/l l-ascorbic acid, and benzylaminopurine (BAP). Embryogenic mass- es were differentiated directly from the kernel explants after culture for 3 weeks in liquid medium with 0.5-4 mg\\/l benzylaminop- urine. After transfer of the embryogenic

  14. Enhanced somatic embryogenesis in sorghum bicolor from shoot tip culture

    Microsoft Academic Search

    Shyamala Bhaskaran; Roberta H. Smith

    1988-01-01

    Summary  Shoot tip cultures from 2- to 3-d-old seedlings ofSorghum bicolor (L.) Moench cv. IS3620C develop highly embryogenic callus from which plants can be regenerated when transferred to plant\\u000a growth regulator-free medium. Isolated shoot tips were cultured on Murashige and Skoog medium supplemented with 2.5 mg\\/liter\\u000a 2,4-dichloro-phenoxyacetic acid and 0.05 mg\\/liter kinetin. Purple pigmentation characteristic of sorghum cultures on growth\\u000a regulator-free

  15. Somatic embryogenesis and plant regeneration of Tripsacum dactyloides L

    Microsoft Academic Search

    Antonella Furini; David C. Jewell

    1991-01-01

    This article reports the culture and plant regeneration of Tripsacum dactyloides. Mature embryos of Tripsacum dactyloides dactyloides were used to obtain embryogenic callus cultures. Currently, 180 normal plants have been regenerated from these cultures. Callus was initiated on MS medium supplemented with dicamba (10 µmol or 20 µmol) and sucrose (3% or 6%), and plants were regenerated on hormone free

  16. Dynamics of biochemical and morphophysiological changes during zygotic embryogenesis in Acca sellowiana (Berg.) Burr

    Microsoft Academic Search

    Gabriela Claudia Cangahuala-Inocente; Vanildo Silveira; Clarissa Alves Caprestano; Jean Pierre Henry Joseph Ducroquet; Eny Iochevet Segal Floh; Miguel Pedro Guerra

    2009-01-01

    Acca sellowiana (Berg.) Burr. is a native Myrtaceae from southern Brazil and Uruguay, now the subject of a domestication and breeding program.\\u000a Biotechnological tools have been used to assist in this program. The establishment of a reliable protocol of somatic embryogenesis\\u000a has been pursued, with a view to capturing and fixing genetic gains. The rationale behind this work relies on

  17. Somatic embryo mediated mass production of Catharanthus roseus in culture vessel (bioreactor) - A comparative study.

    PubMed

    Mujib, A; Ali, Muzamil; Isah, Tasiu; Dipti

    2014-11-01

    The purpose of this study was to evaluate and compare the use of liquid and solid Murashige and Skoog (MS) medium in different culture vessels for mass production of Catharanthus roseus, an important source of anticancerous compounds, vincristine and vinblastine. Three media conditions i.e. agar-solidified medium (S), liquid medium in agitated conical flask (L) and growtek bioreactor (B) were used. Rapid propagation was achieved through in vitro somatic embryogenesis pathway. The process of embryogenesis has been categorized into induction, proliferation, maturation and germination stages. All in vitro embryogenesis stages were conducted by withdrawing spent liquid medium and by adding fresh MS medium. In optimized 4.52 ?M 2,4-D added MS, the callus biomass growth was low in solid (1.65 g) compared to liquid medium in agitated conical flask (1.95 g) and in bioreactor (2.11 g). The number of normal somatic embryos was more in solid medium (99.75/50 mg of callus mass) compared to liquid medium used in conical flask (83.25/callus mass) and growtek bioreactor (84.88/callus mass). The in vitro raised embryos maturated in GA3 (2.60 ?M) added medium; and in bioreactor the embryo growth was high, a maximum length of 9.82 mm was observed at the end of four weeks. These embryos germinated into seedlings in BAP (2.22 ?M) added medium and the embryo germination ability was more (59.41%) in bioreactor compared to liquid medium in conical flask (55.5%). Shoot length (11.25 mm) was also high in bioreactor compared to agitated conical flask. The liquid medium used in agitated conical flask and bioreactor increased seedling production efficiency, at the same time it also reduced plant recovery time. The embryo generated plants grew normally in outdoor conditions. The exploitation of medium to large culture vessel or bioreactor may make the process more efficient in getting large number of Catharanthus plant as it is the only source of anti-cancerous alkaloids, vincristine and vinblastine. PMID:25313279

  18. Somatic embryo mediated mass production of Catharanthus roseus in culture vessel (bioreactor) – A comparative study

    PubMed Central

    Mujib, A.; Ali, Muzamil; Isah, Tasiu; Dipti

    2014-01-01

    The purpose of this study was to evaluate and compare the use of liquid and solid Murashige and Skoog (MS) medium in different culture vessels for mass production of Catharanthus roseus, an important source of anticancerous compounds, vincristine and vinblastine. Three media conditions i.e. agar-solidified medium (S), liquid medium in agitated conical flask (L) and growtek bioreactor (B) were used. Rapid propagation was achieved through in vitro somatic embryogenesis pathway. The process of embryogenesis has been categorized into induction, proliferation, maturation and germination stages. All in vitro embryogenesis stages were conducted by withdrawing spent liquid medium and by adding fresh MS medium. In optimized 4.52 ?M 2,4-D added MS, the callus biomass growth was low in solid (1.65 g) compared to liquid medium in agitated conical flask (1.95 g) and in bioreactor (2.11 g). The number of normal somatic embryos was more in solid medium (99.75/50 mg of callus mass) compared to liquid medium used in conical flask (83.25/callus mass) and growtek bioreactor (84.88/callus mass). The in vitro raised embryos maturated in GA3 (2.60 ?M) added medium; and in bioreactor the embryo growth was high, a maximum length of 9.82 mm was observed at the end of four weeks. These embryos germinated into seedlings in BAP (2.22 ?M) added medium and the embryo germination ability was more (59.41%) in bioreactor compared to liquid medium in conical flask (55.5%). Shoot length (11.25 mm) was also high in bioreactor compared to agitated conical flask. The liquid medium used in agitated conical flask and bioreactor increased seedling production efficiency, at the same time it also reduced plant recovery time. The embryo generated plants grew normally in outdoor conditions. The exploitation of medium to large culture vessel or bioreactor may make the process more efficient in getting large number of Catharanthus plant as it is the only source of anti-cancerous alkaloids, vincristine and vinblastine. PMID:25313279

  19. Characterization of leafy cotyledon1-like during embryogenesis in Theobroma cacao L.

    PubMed

    Alemanno, Laurence; Devic, Martine; Niemenak, Nicolas; Sanier, Christine; Guilleminot, Jocelyne; Rio, Mariannick; Verdeil, Jean-Luc; Montoro, Pascal

    2008-03-01

    Theobroma cacao L., an economically important crop for developing countries, can be experimentally propagated by somatic embryogenesis. Because of their potential roles in embryogenesis, a gene candidate strategy was initiated to find gene homologues of the members of the leafy cotyledon family of transcription factors. A homologue of the leafy cotyledon1-like gene, that encodes the HAP 3 subunit of the CCAAT box-binding factor, was found in the cocoa genome (TcL1L). The translated peptide shared a high amino acid sequence identity with the homologous genes of Arabidopsis thaliana, Phaseolus coccineus and Helianthus annuus. TcL1L transcripts mainly accumulated in young and immature zygotic embryos, and, to a lesser extent, in young and immature somatic embryos. In situ hybridization specified the localization of the transcripts as being mainly in embryonic cells of young embryos, the meristematic cells of the shoot and root apex of immature embryos, and in the protoderm and epidermis of young and immature embryos, either zygotic or somatic. Non-embryogenic explants did not show TcL1L expression. Ectopic expression of the TcL1L gene could partially rescue the Arabidopsis lec1 mutant phenotype, suggesting a similarity of function in zygotic embryogenesis. PMID:18094994

  20. AFLP analysis of variation in pecan somatic embryos

    Microsoft Academic Search

    W. A. Vendrame; G. Kochert; H. Y. Wetzstein

    1999-01-01

    Before somatic embryogenesis can be applied, the genetic fidelity of cultures needs to be determined. Problematic of tissue-cultured\\u000a woody species is the extensive evaluation time needed for assessments. The development of methods whereby plants could be\\u000a rapidly screened for potential tissue culture-derived genetic changes would be very valuable. We evaluated the applicability\\u000a of AFLP (amplified fragment length polymorphism) analysis for

  1. Proliferation, Maturation and Germination of Castanea sativa Mill. Somatic Embryos Originated from Leaf Explants

    PubMed Central

    CORREDOIRA, E.; BALLESTER, A.; VIEITEZ, A. M.

    2003-01-01

    Experiments were performed to determine the influence of proliferation medium on the maintenance of embryogenic competence and on repetitive embryogenesis in Castanea sativa Mill. somatic embryos derived from leaf explants. Somatic embryo proliferation was carried out by both direct secondary embryogenesis and by the culture of nodular callus tissue originated from cotyledons of somatic embryos. Both systems led to the production of cotyledonary somatic embryos on Murashige and Skoog proliferation medium supplemented with 0·1 mg l–1 benzyladenine and 0·1 mg l–1 naphthaleneacetic acid. Carbon source and concentration had a marked influence on maturation and subsequent germination ability of chestnut somatic embryos. Plantlet conversion was achieved in embryos matured on media with 6 % sucrose, and on 3 or 6 % maltose, whereas mean shoot length, root length and leaf number of produced plants were not significantly affected by these maturation media. Overall, the best results were obtained with 3 % maltose?matured somatic embryos, giving rise to 6 % plant recovery in addition to 33 % of embryos exhibiting only shoot development. The application of a 2?month cold treatment at 4 °C to somatic embryos matured on medium with 3 % maltose was necessary for achieving plant conversion, while partial desiccation did not appear to influence this response. A total of 39 % of embryos eventually produced plants either through conversion to plantlets or indirectly through rooting of shoots. Shoots formed by somatic embryos could be excised, multiplied and rooted following the micropropagation procedures previously developed for chestnut. PMID:12763755

  2. Kinetic studies of embryo development and nutrient utilization in an alfalfa direct somatic embryogenic system

    Microsoft Academic Search

    Plamen D. Denchev; Alexander I. Kuklin; Atanas I. Atanassov; Alan H. Scragg

    1993-01-01

    A method for direct somatic embryogenesis in alfalfa (Medicago falcata) is described. The time course in the development phase has been followed for fresh weight, cell density, pH, sugar uptake and embryo number and type. The method of disrupting the explant material has also been shown to influence subsequent embryo formation.

  3. Effects of light on somatic embryo development and abscisic levels in carrot suspension cultures

    Microsoft Academic Search

    Charles H. Michler; R. Daniel Lineberger

    1987-01-01

    Carrot cells were cultured under various light spectra and intensities at different times following the initiation of suspension cultures from callus. The highest intensity white and blue light treatments were inhibitory to growth and somatic embryogenesis. Red and green light were not different from dark treatments which produced the highest total number of embryoids. After extended time in culture, carrot

  4. Influence of Growth Regulators on Callogenesis and Somatic Embryo Development in Date Palm (Phoenix dactylifera L.) Sahelian Cultivars

    PubMed Central

    Sané, Djibril; Aberlenc-Bertossi, Frédérique; Diatta, Léopold Ibrahima Djitiningo; Guèye, Badara; Daher, Abdourahman; Sagna, Maurice; Duval, Yves; Borgel, Alain

    2012-01-01

    This study provides a physiological analysis of somatic embryogenesis in four elite cultivars of date palms: Ahmar, Amsekhsi, Tijib, and Amaside, from the initial callogenesis to establishment and proliferation of embryogenic suspension cultures. Somatic embryos development and in vitro plants rooting were also studied. For each step, auxins and cytokinins concentrations were optimised. The primary callogenesis from leaf explants of seedlings appeared highly dependent on genotype. Ahmar (80%) and Amsekhsi (76%) appeared highly callogenic, whereas Tijib (10%) and Amaside (2%) produced low amounts of calluses. 2,4-Dichlorophenoxyacetic acid appeared favorable to the induction of primary callogenesis and its effect was enhanced by the addition of benzyl adenine or adenine sulfate. Secondary friable calli obtained from chopped granular calli were used to initiate embryogenic cell suspensions in media supplied with 2,4-dichlorophenoxyacetic acid. Suspension cultures showed a growth rate of fourfold after four subcultures in presence of 2,4-dichlorophenoxyacetic acid 2?mg/L. Our results showed that a seven-day transitory treatment with benzyl adenine 0,5?mg/L was necessary to optimize embryos development. Naphthalene acetic acid induced the development of primary orthogravitropic roots during embryos germination. The comparison with cytofluorometry of nuclear DNA amounts showed no significant difference in ploidy level between regenerated plants and seedlings. PMID:22629211

  5. vasa and piwi are required for mitotic integrity in early embryogenesis in the spider Parasteatoda tepidariorum.

    PubMed

    Schwager, Evelyn E; Meng, Yue; Extavour, Cassandra G

    2015-06-15

    Studies in vertebrate and invertebrate model organisms on the molecular basis of primordial germ cell (PGC) specification have revealed that metazoans can specify their germ line either early in development by maternally transmitted cytoplasmic factors (inheritance), or later in development by signaling factors from neighboring tissues (induction). Regardless of the mode of PGC specification, once animal germ cells are specified, they invariably express a number of highly conserved genes. These include vasa and piwi, which can play essential roles in any or all of PGC specification, development, or gametogenesis. Although the arthropods are the most speciose animal phylum, to date there have been no functional studies of conserved germ line genes in species of the most basally branching arthropod clade, the chelicerates (which includes spiders, scorpions, and horseshoe crabs). Here we present the first such study by using molecular and functional tools to examine germ line development and the roles of vasa and piwi orthologues in the common house spider Parasteatoda (formerly Achaearanea) tepidariorum. We use transcript and protein expression patterns of Pt-vasa and Pt-piwi to show that primordial germ cells (PGCs) in the spider arise during late embryogenesis. Neither Pt-vasa nor Pt-piwi gene products are localized asymmetrically to any embryonic region before PGCs emerge as paired segmental clusters in opisthosomal segments 2-6 at late germ band stages. RNA interference studies reveal that both genes are required maternally for egg laying, mitotic progression in early embryos, and embryonic survival. Our results add to the growing body of evidence that vasa and piwi can play important roles in somatic development, and provide evidence for a previously hypothesized conserved role for vasa in cell cycle progression. PMID:25257304

  6. Somatic graviception.

    PubMed

    Mittelstaedt, H

    1996-01-01

    Psychophysical experiments show that the perception of posture is to a large degree affected by hitherto unknown graviceptors in the human trunk. By remote control subjects move themselves radially along their spinal axis over the horizontal platform of a rotating centrifuge until they feel horizontal. Normal subjects then set the centrifuge axis on average at 22-28 cm caudal of the meatus, neuromectomized subjects at 45-55 cm. Hence the mass centroid of these receptors should be situated near the last ribs. Evaluation of the residual faculties of paraplegic patients lead to the conclusion that somatic graviception is mediated by two distinctly localized inputs, the first entering the spinal cord at the 11th thoracic segment, and the second reaching the brain cranial of the 6th cervical segment, presumably via the N. phrenicus or the N. vagus. The effect of the first named input is abolished after bilateral nephrectomy. This proves that the kidneys affect gravity perception. But whether they function like statoliths or in another way cannot yet be decided. For the second input, however, the results show unequivocally that it yields gravity information through the inertia of a mass in the body. It is hypothesized that this mass may be that of the blood in the large vessels. This is corroborated by the effect of shifting blood craniad by means of positive pressure to the legs. It is inferred that the inertial forces are measured by mechanoreceptors in the structures that mechanically support the large vessels, rather than by baroreceptors. PMID:8770370

  7. [Somatization and FSS].

    PubMed

    Tsukui, Kaname; Ebana, Shoichi

    2009-09-01

    In this paper, we discussed the relationship between somatization and functional somatic syndrome (FSS). The concept of somatization takes its origin from the work of Freud S who proposed the idea of conversion as a main defense mechanism. At the same period, the term somatization was introduced by Stekel W as a hypothetical process whereby a deep-seated conflict could cause a bodily disorder. After that, Alexander F developed the emotional equivalents, which had been also proposed by Freud S, into the concept of the vegetative neurosis and psychosomatic diseases. Recently, somatization tends to be defined as 'a tendency to experience and communicate somatic distress in response to psychosocial stress and to seek medical help for it' (Lipowski ZJ, 1988). So there seems to be a strong link among conversion, somatization, FSS, and somatization disorder. PMID:19768900

  8. Tissue culture of Corydalis yanhusuo ( Fumariaceae ) and its medicinal compound production from somatic embryo-derived plants

    Microsoft Academic Search

    S. M. Nalawade; A. P. Sagare; C. L. Kuo; S. F. Lo; C. Y. Lee; Y. L. Lee; H. S. Tsay

    An efficient method for regeneration of entire plants via somatic embryogenesis in Corydalis yanhusuo using tuber-derived callus has been developed. Primary callus was obtained by culturing tuber explants on Murashige and Skoog’s (MS) (1962) medium supplemented with 2.0 mg l?1 N6-benzyladenine (BA) and 0.5 mg l?1 ?-naphthaleneacetic acid (NAA) in darkness for one month. Somatic embryos were induced by subculturing

  9. Hemoglobin Control of Cell Survival/Death Decision Regulates in Vitro Plant Embryogenesis1[W][OPEN

    PubMed Central

    Huang, Shuanglong; Hill, Robert D.; Wally, Owen S.D.; Dionisio, Giuseppe; Ayele, Belay T.; Jami, Sravan Kumar; Stasolla, Claudio

    2014-01-01

    Programmed cell death (PCD) in multicellular organisms is a vital process in growth, development, and stress responses that contributes to the formation of tissues and organs. Although numerous studies have defined the molecular participants in apoptotic and PCD cascades, successful identification of early master regulators that target specific cells to live or die is limited. Using Zea mays somatic embryogenesis as a model system, we report that the expressions of two plant hemoglobin (Hb) genes (ZmHb1 and ZmHb2) regulate the cell survival/death decision that influences somatic embryogenesis through their cell-specific localization patterns. Suppression of either of the two ZmHbs is sufficient to induce PCD through a pathway initiated by elevated NO and Zn2+ levels and mediated by production of reactive oxygen species. The effect of the death program on the fate of the developing embryos is dependent on the localization patterns of the two ZmHbs. During somatic embryogenesis, ZmHb2 transcripts are restricted to a few cells anchoring the embryos to the subtending embryogenic tissue, whereas ZmHb1 transcripts extend to several embryonic domains. Suppression of ZmHb2 induces PCD in the anchoring cells, allowing the embryos to develop further, whereas suppression of ZmHb1 results in massive PCD, leading to abortion. We conclude that regulation of the expression of these ZmHbs has the capability to determine the developmental fate of the embryogenic tissue during somatic embryogenesis through their effect on PCD. This unique regulation might have implications for development and differentiation in other species. PMID:24784758

  10. Stage-specific regulation of four HD-ZIP III transcription factors during polar pattern formation in Larix leptolepis somatic embryos.

    PubMed

    Li, Shui-gen; Li, Wan-feng; Han, Su-ying; Yang, Wen-hua; Qi, Li-wang

    2013-06-15

    Polar auxin transport provides a developmental signal for cell fate specification during somatic embryogenesis. Some members of the HD-ZIP III transcription factors participate in regulation of auxin transport, but little is known about this regulation in somatic embryogenesis. Here, four HD-ZIP III homologues from Larix leptolepis were identified and designated LaHDZ31, 32, 33 and 34. The occurrence of a miR165/166 target sequence in all four cDNA sequences indicated that they might be targets of miR165/166. Identification of the cleavage products of LaHDZ31 and LaHDZ32 in vivo confirmed that they were regulated by miRNA. Their mRNA accumulation patterns during somatic embryogenesis and the effects of 1-N-naphthylphthalamic acid (NPA) on their transcript levels and somatic embryo maturation were investigated. The results showed that the four genes had higher transcript levels at mature stages than at the proliferation stage, and that NPA treatment down-regulated the mRNA abundance of LaHDZ31, 32 and 33 at cotyledonary embryo stages, but had no effect on the mRNA abundance of LaHDZ34. We concluded that these four members of Larix HD-ZIP III family might participate in polar auxin transport and the development of somatic embryos, providing new insights into the regulatory mechanisms of somatic embryogenesis. PMID:23566830

  11. Determination of genetic stability in long-term somatic embryogenic cultures and derived plantlets of cork oak using microsatellite markers.

    PubMed

    Lopes, Tina; Pinto, Glória; Loureiro, João; Costa, Armando; Santos, Conceição

    2006-09-01

    Microsatellites were used to test genetic stability in somatic embryos (SE) of Quercus suber L. The SE were obtained by a simple somatic embryogenesis protocol: leaf explants from two adult plants (QsG0, QsG5) and from two juvenile plants (QsGM1, QsGM2) were inoculated on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid and zeatin. Calluses with primary embryogenic structures were transferred to MSWH (MS medium without growth regulators) and SE proliferated by secondary somatic embryogenesis. High morphological heterogeneity was found among cotyledonary SE. However, converted plants looked morphologically normal with well-developed rooting systems and shoots. The genetic stability of the plant material during the somatic embryogenesis process was evaluated by using six to eight nuclear microsatellites transferred from Q. myrsinifolia Blume, Q. petraea (Matts.) Liebl. and Q. robur L. Five of eight microsatellites distinguished among the genotypes analyzed, and for QsG0, QsGM1 and QsGM2, uniform microsatellite patterns were generally observed within and between SE and the respective donor genotypes. For genotype QsG5, the same pattern was observed in all samples analyzed except one, where the mutation percentage was 2.5%. We conclude that microsatellite markers can be used to assess genetic stability of clonal materials and to determine genetic stability throughout the process of somatic embryogenesis. The simple somatic embryogenesis protocol described has potential for the commercial propagation of Q. suber because it results in a low percentage of mutations. PMID:16740490

  12. Differential gene expression in bovine elongated (Day 17) embryos produced by somatic cell nucleus transfer and in vitro fertilization

    Microsoft Academic Search

    Lleretny Rodríguez-Alvarez; Jutta Sharbati; Soroush Sharbati; José Francisco Cox; Ralf Einspanier; Fidel Ovidio Castro

    2010-01-01

    Somatic cloning in cattle is associated with impaired embryo development, caused by inappropriate epigenetic reprogramming during embryogenesis; however, there is a paucity of data regarding gene expression at the critical elongation and peri-implantation stages. The objective of the present study was to identify genes differentially expressed in bovine cloned embryos at Day 17 of development (Day 0=day of nucleus transfer

  13. Somatization, Paranoia, and Language.

    ERIC Educational Resources Information Center

    Oxman, Thomas E.; And Others

    1988-01-01

    Free speech of subjects with somatization and paranoia was analyzed to identify and compare self-concept dimensions reflected in their lexical choices. The somatization disorder group conveyed a sense of negativism, distress, and preoccupation with an uncertain self-identity. The paranoid patients portrayed an artificially positive, grandiose…

  14. Somatic hybridization in Citrus: navel orange (C. sinensis Osb.) and grapefruit (C. paradisi Macf.).

    PubMed

    Ohgawara, T; Kobayashi, S; Ishii, S; Yoshinaga, K; Oiyama, I

    1989-11-01

    Protoplasts of navel orange, isolated from embryogenic nucellar cell suspension culture, were fused with protoplasts of grapefruit isolated from leaf tissue. The fusion products were cultured in the hormone-free medium containing 0.6 M sucrose. Under the culture conditions, somatic embryogenesis of navel orange protoplasts was suppressed, while cell division of grapefruit mesophyll protoplasts was not induced. Six embryoids were obtained and three lines regenerated to complete plants through embryogenesis. Two of the regenerated lines exhibited intermediate morphological characteristics of the parents in the leaf shape. Chromosome counts showed that these regenerated plants had expected 36 chromosomes (2n=2x=18 for each parent). The rDNA analysis using biotin-labeled rRNA probes confirmed the presence of genomes from both parents in these plants. This somatic hybridization system would be useful for the practical Citrus breeding. PMID:24225818

  15. Microspore embryogenesis in wheat: new marker genes for early, middle and late stages of embryo development.

    PubMed

    Sánchez-Díaz, Rosa Angélica; Castillo, Ana María; Vallés, María Pilar

    2013-09-01

    Microspore embryogenesis involves reprogramming of the pollen immature cell towards embryogenesis. We have identified and characterized a collection of 14 genes induced along different morphological phases of microspore-derived embryo development in wheat (Triticum aestivum L.) anther culture. SERKs and FLAs genes previously associated with somatic embryogenesis and reproductive tissues, respectively, were also included in this analysis. Genes involved in signalling mechanisms such as TaTPD1-like and TAA1b, and two glutathione S-transferase (GSTF2 and GSTA2) were induced when microspores had acquired a 'star-like' morphology or had undergone the first divisions. Genes associated with control of plant development and stress response (TaNF-YA, TaAGL14, TaFLA26, CHI3, XIP-R; Tad1 and WALI6) were activated before exine rupture. When the multicellular structures have been released from the exine, TaEXPB4, TaAGP31-like and an unknown embryo-specific gene TaME1 were induced. Comparison of gene expression, between two wheat cultivars with different response to anther culture, showed that the profile of genes activated before exine rupture was shifted to earlier stages in the low responding cultivar. This collection of genes constitutes a value resource for study mechanism of intra-embryo communication, early pattern formation, cell wall modification and embryo differentiation. PMID:23839308

  16. Development and germination of pecan somatic embryos derived from liquid culture

    Microsoft Academic Search

    J. Austin Burns; Hazel Y. Wetzstein

    1995-01-01

    Aggregates of globular and pre-globular stage somatic embryos from suspension cultures of pecan (Carya illinoensis Koch) were cultured on solidified media for embryo development. Embryo aggregates and pre-globular stage embryo masses were\\u000a given various treatments to further ontologic development. A 2- to 4-wk mild dehydration of the embryo aggregates suppressed\\u000a recurrent embryogenesis, promoted development of globular embryos into cotyledonary stage

  17. Differential proteomic analysis of developmental stages of Acca sellowiana somatic embryos

    Microsoft Academic Search

    Gabriela Claudia Cangahuala-Inocente; Andrea Villarino; Daniela Seixas; Eliane Dumas-Gaudot; Hernán Terenzi; Miguel Pedro Guerra

    2009-01-01

    Feijoa (Acca sellowiana, Myrtaceae), a native fruit species from southern Brazil and northern Uruguay, is considered to constitute a reference system\\u000a for somatic embryogenesis in woody dicots. This in vitro regenerative pathway is an efficient micropropagation method, and\\u000a a suitable model system for studies in plant developmental physiology. This study attempts to detect and identify proteins\\u000a that are expressed during

  18. Somatization and conversion disorder.

    PubMed

    Hurwitz, Trevor A

    2004-03-01

    Somatization is the psychological mechanism whereby psychological distress is expressed in the form of physical symptoms. The psychological distress in somatization is most commonly caused by a mood disorder that threatens mental stability. Conversion disorder occurs when the somatic presentation involves any aspect of the central nervous system over which voluntary control is exercised. Conversion reactions represent fixed ideas about neurologic malfunction that are consciously enacted, resulting in psychogenic neurologic deficits. Treatment is complex and lengthy; it includes recovery of neurologic function aided by narcoanalysis and identification and treatment of the primary psychiatric disorder, usually a mood disorder. PMID:15101499

  19. Piwi regulates Vasa accumulation during embryogenesis in the sea urchin

    PubMed Central

    Yajima, Mamiko; Gustafson, Eric A.; Song, Jia L.; Wessel, Gary M.

    2014-01-01

    Background Piwi proteins are essential for germ line development, stem cell maintenance, and more recently found to function in epigenetic and somatic gene regulation. In the sea urchin Strongylocentrotus purpuratus, two Piwi proteins, Seawi and Piwi-like1, have been identified, yet their functional contributions have not been reported. Result Here we found that Seawi protein was localized uniformly in the early embryo and then became enriched in the primordial germ cells (PGCs) (the small micromere lineage) from blastula stage and thereafter. Morpholino knockdown of Sp-seawi diminished PGC-specific localization of Seawi proteins, and altered expression of other germ line markers such as Vasa and Gustavus, but had no effect on Nanos. Further, Seawi knockdown transiently resulted in Vasa positive cell proliferation in the right coelomic pouch that appear to be derived from the small micromere lineage, yet they quickly disappeared with an indication of apoptosis by larval stage. Severe Seawi knockdown resulted in an increased number of apoptotic cells in the entire gut area. Piwi proteins appear to regulate PGC proliferation perhaps through control of Vasa accumulation. In this organism, Piwi is likely regulating mRNAs, not just transposons, and is potentially functioning both inside and outside of the germ line during embryogenesis. PMID:24218044

  20. Somatic mutations of KIT in familial testicular germ cell tumours.

    PubMed

    Rapley, E A; Hockley, S; Warren, W; Johnson, L; Huddart, R; Crockford, G; Forman, D; Leahy, M G; Oliver, D T; Tucker, K; Friedlander, M; Phillips, K-A; Hogg, D; Jewett, M A S; Lohynska, R; Daugaard, G; Richard, S; Heidenreich, A; Geczi, L; Bodrogi, I; Olah, E; Ormiston, W J; Daly, P A; Looijenga, L H J; Guilford, P; Aass, N; Fosså, S D; Heimdal, K; Tjulandin, S A; Liubchenko, L; Stoll, H; Weber, W; Einhorn, L; Weber, B L; McMaster, M; Greene, M H; Bishop, D T; Easton, D; Stratton, M R

    2004-06-14

    Somatic mutations of the KIT gene have been reported in mast cell diseases and gastrointestinal stromal tumours. Recently, they have also been found in mediastinal and testicular germ cell tumours (TGCTs), particularly in cases with bilateral disease. We screened the KIT coding sequence (except exon 1) for germline mutations in 240 pedigrees with two or more cases of TGCT. No germline mutations were found. Exons 10, 11 and 17 of KIT were examined for somatic mutations in 123 TGCT from 93 multiple-case testicular cancer families. Five somatic mutations were identified; four were missense amino-acid substitutions in exon 17 and one was a 12 bp in-frame deletion in exon 11. Two of seven TGCT from cases with bilateral disease carried KIT mutations compared with three out of 116 unilateral cases (P=0.026). The results indicate that somatic KIT mutations are implicated in the development of a minority of familial as well as sporadic TGCT. They also lend support to the hypothesis that KIT mutations primarily take place during embryogenesis such that primordial germ cells with KIT mutations are distributed to both testes. PMID:15150569

  1. Left-Right Asymmetry in Animal Embryogenesis

    E-print Network

    Levin, Michael

    1 Left-Right Asymmetry in Animal Embryogenesis Michael Levin Cell Biology dept. Bldg. C1, rm. 403 of a given type) differences between the left and right sides of an animal's morphology. This specifically of an organism looking the same to some level of detail on either side of a symmetry line). Animal body- plans

  2. Comparative and experimental embryogenesis of Plectidae (Nematoda)

    Microsoft Academic Search

    Vera Lahl; Christian Halama; Einhard Schierenberg

    2003-01-01

    Comparative analysis of early embryogenesis indicates that considerable differences exist among nematode species. To better understand to what extent the well-studied development of Caenorhabditis elegans is representative for nematodes in general, we extended our earlier studies to other families of this phylum. Here we report our findings on seven species of Plectidae. We found that Plectidae embryos share a number

  3. Embryogenesis in callus derived from rice microspores

    Microsoft Academic Search

    A. D. Genovesi; C. W. Magill

    1982-01-01

    Differentiating calli derived from rice (Oryza sativa L.) microspores were examined histologically. Shoot and root meristems were observed to be arising by both organogenesis as well as embryogenesis. Embryoid attachment to callus (as well as other embryoids) was at the scutellum adjacent to the mesocotyl and radicle. These observations could be interpreted as an indication of the totipotent plasticity of

  4. Somatic cell nuclear transfer

    Microsoft Academic Search

    I. Wilmut; N. Beaujean; P. A. de Sousa; A. Dinnyes; T. J. King; L. A. Paterson; D. N. Wells; L. E. Young

    2002-01-01

    Cloning by nuclear transfer from adult somatic cells is a remarkable demonstration of developmental plasticity. When a nucleus is placed in oocyte cytoplasm, the changes in chromatin structure that govern differentiation can be reversed, and the nucleus can be made to control development to term.

  5. Shusterman on Somatic Experience

    ERIC Educational Resources Information Center

    Maattanen, Pentti

    2010-01-01

    Richard Shusterman's "Body Consciousness" aims at formulating a theory of somaesthetics and somatic experience. There has indeed been a growing interest in the role of the body in experience. Shusterman examines the arguments of six important writers who have been influential in this discussion. The emphasis on the body is natural for a…

  6. Periderm prevents pathological epithelial adhesions during embryogenesis

    PubMed Central

    Richardson, Rebecca J.; Hammond, Nigel L.; Coulombe, Pierre A.; Saloranta, Carola; Nousiainen, Heidi O.; Salonen, Riitta; Berry, Andrew; Hanley, Neil; Headon, Denis; Karikoski, Riitta; Dixon, Michael J.

    2014-01-01

    Appropriate development of stratified, squamous, keratinizing epithelia, such as the epidermis and oral epithelia, generates an outer protective permeability barrier that prevents water loss, entry of toxins, and microbial invasion. During embryogenesis, the immature ectoderm initially consists of a single layer of undifferentiated, cuboidal epithelial cells that stratifies to produce an outer layer of flattened periderm cells of unknown function. Here, we determined that periderm cells form in a distinct pattern early in embryogenesis, exhibit highly polarized expression of adhesion complexes, and are shed from the outer surface of the embryo late in development. Mice carrying loss-of-function mutations in the genes encoding IFN regulatory factor 6 (IRF6), I?B kinase-? (IKK?), and stratifin (SFN) exhibit abnormal epidermal development, and we determined that mutant animals exhibit dysfunctional periderm formation, resulting in abnormal intracellular adhesions. Furthermore, tissue from a fetus with cocoon syndrome, a lethal disorder that results from a nonsense mutation in IKKA, revealed an absence of periderm. Together, these data indicate that periderm plays a transient but fundamental role during embryogenesis by acting as a protective barrier that prevents pathological adhesion between immature, adhesion-competent epithelia. Furthermore, this study suggests that failure of periderm formation underlies a series of devastating birth defects, including popliteal pterygium syndrome, cocoon syndrome, and Bartsocas-Papas syndrome. PMID:25133425

  7. Ultrastructural characterization of somatic embryos regenerated from NaCl selected and nonselected calli of Dactylis glomerata

    Microsoft Academic Search

    S. Dutta Gupta; P. A. Joshi; J. C. Hovanesian; B. V. Conger

    1992-01-01

    Summary Calli were induced from leaf expiants of aDactylis glomerata L. (orchardgrass) genotype which has a high capacity for somatic embryogenesis. After 7 months culture on SH medium containing NaCl, a line was selected which was tolerant to 200 mM NaCl. When both selected and nonselected calli were maintained for 56 days on media containing 0 to 300 mM NaCl,

  8. Effects of p-chlorophenoxyisobutyric acid, arabinogalactan, and activated charcoal on microspore embryogenesis in kale.

    PubMed

    Niu, R Q; Zhang, Y; Tong, Y; Liu, Z Y; Wang, Y H; Feng, H

    2015-01-01

    To improve embryogenesis in microspore cultures of kale (Brassica oleracea L. var. acephala DC.), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA), arabinogalactan (AG), p-chlo-rophenoxyisobutyric acid (PCIB), and activated charcoal (AC) were added to the medium using four varieties of kale. The results showed that the addition of AG (0.1-0.2 g/L), AC (0.1-0.2 g/L) or a combination of 6-BA (0.1-0.2 mg/L) and NAA (0.1-0.2 mg/L) promoted embryo-genesis. Adding 40 ?M PCIB or a combination of 40 ?M PCIB and 0.2 g/L AC to NLN-13 medium at pH 5.8 effectively enhanced embryogen-esis. Treatment with a combination of 40 ?M PCIB and 10 mg/L AG gave the highest rate of embryonic induction, especially in genotype "Y007," which showed a twelve-fold increase in yield. PMID:25966161

  9. Asymmetric Wolbachia Segregation during Early Brugia malayi Embryogenesis Determines Its Distribution in Adult Host Tissues

    PubMed Central

    Landmann, Frédéric; Foster, Jeremy M.; Slatko, Barton; Sullivan, William

    2010-01-01

    Wolbachia are required for filarial nematode survival and fertility and contribute to the immune responses associated with human filarial diseases. Here we developed whole-mount immunofluorescence techniques to characterize Wolbachia somatic and germline transmission patterns and tissue distribution in Brugia malayi, a nematode responsible for lymphatic filariasis. In the initial embryonic divisions, Wolbachia segregate asymmetrically such that they occupy only a small subset of cells in the developing embryo, facilitating their concentration in the adult hypodermal chords and female germline. Wolbachia are not found in male reproductive tissues and the absence of Wolbachia from embryonic germline precursors in half of the embryos indicates Wolbachia loss from the male germline may occur in early embryogenesis. Wolbachia rely on fusion of hypodermal cells to populate adult chords. Finally, we detect Wolbachia in the secretory canal lumen suggesting living worms may release bacteria and/or their products into their host. PMID:20689574

  10. Isolation of an embryogenic line from non-embryogenic Brassica napus cv. Westar through microspore embryogenesis

    PubMed Central

    Malik, Meghna R.; Wang, Feng; Dirpaul, Joan M.; Zhou, Ning; Hammerlindl, Joe; Keller, Wilf; Abrams, Suzanne R.; Ferrie, Alison M. R.; Krochko, Joan E.

    2008-01-01

    Brassica napus cultivar Westar is non-embryogenic under all standard protocols for induction of microspore embryogenesis; however, the rare embryos produced in Westar microspore cultures, induced with added brassinosteroids, were found to develop into heritably stable embryogenic lines after chromosome doubling. One of the Westar-derived doubled haploid (DH) lines, DH-2, produced up to 30% the number of embryos as the highly embryogenic B. napus line, Topas DH4079. Expression analysis of marker genes for embryogenesis in Westar and the derived DH-2 line, using real-time reverse transcription-PCR, revealed that the timely expression of embryogenesis-related genes such as LEAFY COTYLEDON1 (LEC1), LEC2, ABSCISIC ACID INSENSITIVE3, and BABY BOOM1, and an accompanying down-regulation of pollen-related transcripts, were associated with commitment to embryo development in Brassica microspores. Microarray comparisons of 7?d cultures of Westar and Westar DH-2, using a B. napus seed-focused cDNA array (10?642 unigenes), identified highly expressed genes related to protein synthesis, translation, and response to stimulus (Gene Ontology) in the embryogenic DH-2 microspore-derived cell cultures. In contrast, transcripts for pollen-expressed genes were predominant in the recalcitrant Westar microspores. Besides being embryogenic, DH-2 plants showed alterations in morphology and architecture as compared with Westar, for example epinastic leaves, non-abscised petals, pale flower colour, and longer lateral branches. Auxin, cytokinin, and abscisic acid (ABA) profiles in young leaves, mature leaves, and inflorescences of Westar and DH-2 revealed no significant differences that could account for the alterations in embryogenic potential or phenotype. Various mechanisms accounting for the increased capacity for embryogenesis in Westar-derived DH lines are considered. PMID:18552352

  11. Managing somatization disorder.

    PubMed

    Morrison, J

    1990-10-01

    Somatization disorder (SD), a chronic psychiatric illness that affects about 1% of adult women, is characterized by multiple somatic complaints. It should be suspected in any woman who presents with a vague or complicated history; unaccountable non-responsiveness to therapy; dramatic, seductive or demanding personality style; family history of personality disorder; sexual abuse as a child; substance abuse; or depression with atypical features. Its cause is unknown, although both genetic and environmental factors have been implicated. At follow-up, patients with SD continue to have somatic symptoms, but many improve with therapy. Nearly two thirds of patients with SD attempt suicide, but few complete it; however, completions may be more common than formerly realized. There is no specific treatment for SD, but management can be organized around the following ABCs: Accommodate initially to forge rapport; Behavior modification (ignore symptoms, praise for improved behavior); Confrontation later about effects of behavior style; Decrease drugs gradually, with praise for reduction; Educate about course and meaning of illness; Family involvement to give information and help with treatment; Guilt should be assuaged in physicians, who may blame themselves when patients do not improve; Hospitalize (closed psychiatric unit) only for serious suicide risk, substance abuse, or other extreme behavior; and Intercurrent depression should be treated conservatively. PMID:2209356

  12. Diverse roles of actin in C. elegans early embryogenesis

    Microsoft Academic Search

    Nathalie Velarde; Kristin C Gunsalus; Fabio Piano

    2007-01-01

    BACKGROUND: The actin cytoskeleton plays critical roles in early development in Caenorhabditis elegans. To further understand the complex roles of actin in early embryogenesis we use RNAi and in vivo imaging of filamentous actin (F-actin) dynamics. RESULTS: Using RNAi, we found processes that are differentially sensitive to levels of actin during early embryogenesis. Mild actin depletion shows defects in cortical

  13. Real-time Embryogenesis in Live Caenorhabditis elegans Worms

    NSDL National Science Digital Library

    Dr. Anita G Fernandez (Fairfield University Biology)

    2011-11-21

    This is a lab exercise geared toward first-year undergraduate biology majors, where they get to view early embryogenesis in a live animal. In this exercise students will prepare slides if live C. elegans embryos, find one- or two-cell stage embryos, and observe cleavage stage of embryogenesis over the course of 30 minutes.

  14. Induction of embryogenic Triticum aestivum L. calli. II. Quantification of organic addenda and other culture variable effects

    Microsoft Academic Search

    John G. Carman; Nancy E. Jefferson; William F. Campbell

    1987-01-01

    Nine experiments were conducted to determine effects of various culture medium addenda on inducation of embryogenic calli from immature embryos of a responsive Triticum aestivum L. genotype (PCYT 10). Effects were quantified by counting somatic embryos (embryoids) per callus. Optimal auxin concentrations to induce and maintain somatic embryogenesis were 3.62 µM 2,4-dichlorophenoxyacetic acid (2,4-D) or 9.05 µM 3,6-dichloro-o-anisic acid (dicamba).

  15. ENHANCING THE FREQUENCY OF SOMATIC EMBRYOGENESIS FOLLOWING AGROBACTERIUM-MEDIATED TRANSFORMATION OF

    E-print Network

    Korban, Schuyler S.

    transgenic plants (Yan et al., 2000; Ko et al., 2003). Shoot meristems have been utilized in particle gun). Moreover, transgenic plants obtained from these tissues are often sterile (Trick and Finer, 1998), thus of fertile transgenic soybean plants reported by Hinchee et al. (1988), there have been several reports

  16. Plant regeneration from callus and protoplasts of Brassica nigra (IC 257) through somatic embryogenesis

    Microsoft Academic Search

    Vibha Gupta; Abha Agnihotri; V. Jagannathan

    1990-01-01

    A method to obtain plants from embryogenic callus of Brassica nigra and protoplasts of hypocotyl expiants is described. Callus was initiated on Murashige and Skoog medium containing kinetin (kn) and 2,4-dichlorophenoxy acetic acid (2,4-D). Lowering of auxin induced embryo formation. Supplementation with gibberellic acid (GA3) enhanced embryogenic response tenfold. Passage through liquid medium devoid of growth regulators was essential for

  17. Y.-S. ParkConifer somatic embryogenesis in clonal forestry Original article

    E-print Network

    Paris-Sud XI, Université de

    and genetic stability of clones is re- viewed, using white spruce (Picea glauca) and eastern white pine (Pinus en utilisant comme espèces modèles l'épinette blanche (Picea glauca) et le pin blanc (Pinus strobus

  18. Rapid transformation and regeneration of alfalfa (Medicago falcata L.) via direct somatic embryogenesis

    Microsoft Academic Search

    C. Y. Shao; E. Russinova; A. Iantcheva; A. Atanassov; A. McCormac; D. F. Chen; M. C. Elliott; A. Slater

    2000-01-01

    Two simple, rapid and efficient protocols for theregeneration of transformed tetraploid lines ofalfalfa (Medicago falcata L.) have beendeveloped and compared. Leaf explants fromembryogenic lines 47\\/1-150 and 47\\/1-5 were inoculatedwith Agrobacterium tumefaciens containingconstructs carrying the nptII selectable markergene and promoter:gusA gene fusions under thecontrol of the CaMV 35S or Arabidopsis cdc2a,CycB1 and CycA2 promoters. In the firstregeneration system (the MSH system),

  19. Somatic embryogenesis and massive shoot regeneration from immature embryo explants of tef.

    PubMed

    Gugsa, Likyelesh; Kumlehn, Jochen

    2011-01-01

    Tef (Eragrostis tef) provides a major source of human nutrition in the Horn of Africa, but biotechnology has had little impact on its improvement to date. Here, we report the elaboration of an in vitro regeneration protocol, based on the use of immature zygotic embryos as explant. Explant size was an important determinant of in vitro regeneration efficiency, as was the formulation of the culture medium. Optimal results were obtained by culturing 0.2-0.35?mm embryo explants on a medium containing KBP minerals, 9.2-13.8??M 2,4-dichlorophenoxyacetic acid, 6?mM glutamine, and 0.5% Phytagel. Although this protocol was effective for both the improved cultivar "DZ-01-196" and the landrace "Fesho", the former produced consistently more embryogenic tissue and a higher number of regenerants. An average of more than 2,800 shoots could be obtained from each "DZ-01-196" explant after 12 weeks of in vitro culture. These shoots readily formed roots, and plantlets transferred to soil were able to develop into morphologically normal, fertile plants. This regeneration and multiplication system should allow for the application of a range of biotechnological methods to tef. PMID:22028975

  20. Somatic embryogenesis and callus production from cotyledon explants of Eastern black walnut

    Microsoft Academic Search

    Mark C. Neuman; John E. Preece; J. W. Sambeek; Gerald R. Gaffney

    1993-01-01

    Starting at 8 weeks and continuing until 23 weeks (nut drop) after anthesis,1 m2 explants from cotyledons of immature seeds were extracted from Juglans nigra fruits. Explants were placed on Woody Plant Medium with 1 g l-1 casein hydrolysate and 30 g l-1 sucrose. The explants remained in light for 4 weeks on primary media containing a 3×3 factorial of

  1. Plant regeneration via somatic embryogenesis of Elymus sibiricus cv . ‘ chuancao No. 2 ’

    Microsoft Academic Search

    Daxu Li; Jie Zhang; Jian Zhao; Yi Zhang; Fei Chen; Jingqiu Zhu; Shujun Liu; Zhirong Yang

    2006-01-01

    The mature seeds, mesocotyls, and young leaf tips of Elymus  sibiricus L. cv. ‘chuancao No. 2’ were cultured on Murashige and Skoog (MS) medium supplemented with 5.0 mg\\/L 2,4-dichlorophenoxyacetic acid (2,4-d) and 0.05 mg\\/L kinetin in the dark at 26°C, the calluses were produced. The rate of callus regeneration depended on the explants\\u000a source and plant growth regulators. Plants regenerated from whitish-yellow-coloured

  2. Somatic Embryogenesis of Pine Species: From Functional Genomics to Plantation Forestry

    Microsoft Academic Search

    Hely Häggman; Jaana Vuosku; Tytti Sarjala; Anne Jokela; Karoliina Niemi

    Several economically important tree species belong to the genus Pinus\\u000a and many of them form the ecological base of forest ecosystems. Pine wood is an important raw material\\u000a for the forest industry and many of the pine species have been involved in conventional tree improvement\\u000a programmes. A lot of effort has been made in the development of vegetative propagation methods,\\u000a especially

  3. Advances in somatic embryogenesis and plant production of black locust ( Robinia pseudoacacia L.)

    Microsoft Academic Search

    I. Arrillaga; J. J. Tobolski; S. A. Merkle

    1994-01-01

    Black locust (Robinia pseudoacacia L.) immature seeds of different developmental stages were tested for the ability to initiate embryogenic cultures. Best results (average of 12% embryogenic cultures) were obtained when seeds collected 2–3 weeks post-anthesis were cultured for 3 weeks on modified Finer and Nagasawa medium containing 2,4-D (45–90 µM) and BA (2.2 µM) and then transferred to the same

  4. Effect of weightlessness conditions on the somatic embryogenesis in the culture of carrot cells

    NASA Technical Reports Server (NTRS)

    Butenko, R. G.; Dmitriyeva, N. N.; Ongko, V.; Basyrova, L. V.

    1977-01-01

    A carrot cell culture seeded in Petri dishes in the United States and transported to the USSR was subjected to weightlessness for 20 days during the flight of Kosmos 782. The controls were cultures placed on a centrifuge (1 g) inside the satellite and cultures left on ground in the U.S.S.R. and the United States. A count of structures in the dishes after the flight showed that the number of developing embryonic structures and the extent of their differentiation in weightlessness did not reliably differ from the number and extent of differentiation in structures developed on the ground. Structures with long roots developed in weightlessness. Analysis of the root zones showed that these roots differed by the increased size of the zone of differentiated cells. The increased size of the zones of differentiated cells can indicate earlier development of embryonic structures.

  5. In vitro plantlet formation by organogenesis in E. camaldulensis and by somatic embryogenesis in Eucalyptus citriodora

    Microsoft Academic Search

    E. M. Muralidharan; A. F. Mascarenhas

    1987-01-01

    Adventitious shoots were formed through callus on leaf explants of Eucalyptus camaldulensis Dehnh. (River red gum) taken from shoot cultures of mature trees. Callus formed in dark on a medium containing 1 g\\/l casein hydrolysate, 3 mg\\/l 1-naphthaleneacetic acid, 0.1 mg\\/l 6-benzyladenine and 50 g\\/l sucrose. Shoot initiation occurred in 4 weeks on calli shifted to light on a regeneration

  6. Incorporating Multiple cDNA Microarray Slide Scans -Application to Somatic Embryogenesis in Maize

    E-print Network

    and the sensitivities of the camera result in different images. While a setting for laser and camera may produce a large expression below the minimum that can be captured by the instruments. The laser strength and the sensitivity of the camera to light can be adjusted by the operator to find a `best' picture, one where most of the spots

  7. Gene Expression Patterns During Somatic Embryogenesis in Maize Tissue Culture: A Bayesian Approach

    E-print Network

    strengths and the sensitivities of the camera result in different images. While a setting for laser. The laser strength and the sensitivity of the camera to light can be adjusted by the operator to find the strength of the laser and the sensitivity of the camera used to record expression levels and propose

  8. Somatic embryogenesis in Ranunculus asiaticus L. hybr. thalamus cultivated in vitro

    Microsoft Academic Search

    Margherita Beruto I; Pierre Debergh

    1992-01-01

    Calli derived from in vitro cultivated thalamus of Ranunculus asiaticus L. were initiated and maintained for 75 days on Murashige & Skoog's medium containing five concentrations of 2,4-d (0.1, 0.2, 0.4, 0.8, 1.6 mg l-1). Embryoid differentiation occurred on calli initiated on 1.6 mg l-1 2,4-d 75 days after subculture onto hormone-free medium. Calli which were initiated and maintained for

  9. In vitro propagation of an endangered medicinal herb Chlorophytum borivilianum Sant. et Fernand. through somatic embryogenesis

    Microsoft Academic Search

    Mohd Zahid Rizvi; Arun Kumar Kukreja; Narendra Singh Bisht

    2010-01-01

    Tuberous roots of Chlorophytum borivilianum Sant. et Fernand. which are a source of steroidal saponins, possess immunomodulatory, adaptogenic, aphrodisiac, antipyretic,\\u000a diuretic, hemostatic and anti-tumour properties. Poor seed setting and germination and slow growth in conventional vegetative\\u000a propagation are major constraints in the large-scale cultivation of this commercially important medicinal plant. In the present\\u000a study, a procedure for in vitro propagation

  10. Somatic embryogenesis of carrot in hormone-free medium: external pH control over morphogenesis

    NASA Technical Reports Server (NTRS)

    Smith, D. L.; Krikorian, A. D.

    1990-01-01

    Cultures of preglobular stage proembryos (PGSPs) were initiated from mechanically wounded mature zygotic embryos of carrot, Daucus carota, on a hormone-free, semisolid medium. These PGSPs have been maintained and multiplied for extended periods without their progression into later embryo stages on the same hormone-free medium containing 1 mM NH4+ as the sole nitrogen source. Sustained maintenance of cultures comprised exclusively of PGSPs was dependent on medium pH throughout the culture period. Best growth and multiplication of PGSP cultures occurred when the pH of unbuffered, hormone-free medium fell from 4.5 to 4 over a 2-week period or when buffered medium was titrated to pH 4. If the hormone-free medium was buffered to sustain a pH at or above 4.5, PGSPs developed into later embryo stages. Maintenance with continuous multiplication of PGSPs occurred equally well on medium containing NH4+ or NH4+ and NO3-, but growth was poor with NO3- alone. Additional observations on the effects of medium components such as various nitrogen sources and levels, sucrose concentration, semisolid supports, type of buffer, borate concentration, activated charcoal, and initial pH that permit optimum maintenance of the PGSPs or foster their continued developmental progression into mature embryos and plantlets are reported. The influence of the pH of the hormone-free medium as a determinant in maintaining cultures as PGSPs or allowing their continued embryonic development are unequivocally demonstrated by gross morphology, scanning electron microscopy, and histological preparations.

  11. Rapid plant regeneration through organogenesis and somatic embryogenesis from cultured protoplasts of Brassica juncea

    Microsoft Academic Search

    P. B. Kirti; V. L. Chopra

    1990-01-01

    Protoplasts derived from hypocotyls of seedlings grown on half-strength MS medium containing 1% sucrose were cultured at a density of 5×104 ml-1 in Kao's medium supplemented with 1.0 mgl-12,4-D, 0.1 mgl-1 NAA and 0.5 mgl-1 zeatin riboside. After three days of culture in darkness at 25±1°C, cultures were transferred to light (70 µEm-2s-1) in a 16\\/8 h ligø ht\\/dark cycle.

  12. Somatic embryogenesis and plant regeneration from protoplasts of asparagus ( Asparagus officinalis L.)

    Microsoft Academic Search

    Hisato Kunitake; Masahiro Mii

    1990-01-01

    Protoplasts were isolated from embryogenic calli of Asparagus officinalis L. cv. Mary Washington and cultured in 1\\/2 MS medium with 1 mg\\/l NAA, 0.5 mg\\/l zeatin, 1 g\\/l L-glutamine, 0.6 M glucose and 0.1% Gellan Gum. Protoplasts started to divide after 3–4 d of culture and formed visible colonies after 30 d of culture. The percentage of colony formation (plating

  13. Late Embryogenesis Abundant (LEA) proteins in legumes

    PubMed Central

    Battaglia, Marina; Covarrubias, Alejandra A.

    2013-01-01

    Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan, and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirm the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions. PMID:23805145

  14. 5-azacytidine promotes microspore embryogenesis initiation by decreasing global DNA methylation, but prevents subsequent embryo development in rapeseed and barley

    PubMed Central

    Solís, María-Teresa; El-Tantawy, Ahmed-Abdalla; Cano, Vanesa; Risueño, María C.; Testillano, Pilar S.

    2015-01-01

    Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypomethylation. AzaC is a useful demethylating agent to study DNA dynamics, with a potential application in microspore embryogenesis. This work analyzes the effects of short and long AzaC treatments on microspore embryogenesis initiation and progression in two species, the dicot Brassica napus and the monocot Hordeum vulgare. This involved the quantitative analyses of proembryo and embryo production, the quantification of DNA methylation, 5-methyl-deoxy-cytidine (5mdC) immunofluorescence and confocal microscopy, and the analysis of chromatin organization (condensation/decondensation) by light and electron microscopy. Four days of AzaC treatments (2.5 ?M) increased embryo induction, response associated with a decrease of DNA methylation, modified 5mdC, and heterochromatin patterns compared to untreated embryos. By contrast, longer AzaC treatments diminished embryo production. Similar effects were found in both species, indicating that DNA demethylation promotes microspore reprogramming, totipotency acquisition, and embryogenesis initiation, while embryo differentiation requires de novo DNA methylation and is prevented by AzaC. This suggests a role for DNA methylation in the repression of microspore reprogramming and possibly totipotency acquisition. Results provide new insights into the role of epigenetic modifications in microspore embryogenesis and suggest a potential benefit of inhibitors, such as AzaC, to improve the process efficiency in biotechnology and breeding programs. PMID:26161085

  15. Changes in pectins and MAPKs related to cell development during early microspore embryogenesis in Quercus suber L.

    PubMed

    Ramírez, Carmen; Testillano, Pilar S; Pintos, Beatriz; Moreno-Risueño, Miguel A; Bueno, María A; Risueño, María C

    2004-07-01

    The occurrence and significance of changes in cell wall components and signalling molecules has been investigated during early microspore embryogenesis in cork oak (Quercus suber L.) in relation to cell proliferation and cell differentiation. Microspore embryogenesis has been induced in in vitro anther cultures of Q. suber by the application of a stress treatment of 33 degrees C. After the treatment, microspores at the responsive developmental stage of vacuolate microspore switched towards proliferation and the embryogenesis pathway to further produce haploid plantlets. Ultrastructural and immunocytochemical analysis revealed changes in cell organisation after induction at different developmental stages, the cellular features displayed being in relation to the activation of proliferative activity and the beginning of differentiation in young and late proembryos. Immunogold labelling with JIM5 and JIM7 antibodies showed a different presence of pectin and level of its esterification in cell walls at different developmental stages. Non-esterified pectins were found in higher proportions in cells of late proembryos, suggesting that pectin de-esterification could be related to the beginning of differentiation. The presence and subcellular distribution of Erk 1/2 MAPK homologues have been investigated by immunoblotting, immunofluorescence and immunogold labelling. The results showed an increase in the expression of these proteins with a high presence in the nucleus, during early microspore proembryos development. The reported changes during early microspore embryogenesis are modulated in relation to proliferation and differentiation events. These findings provided new evidences for a role of MAPK signalling pathways in early microspore embryogenesis, specifically in proliferation, and would confer information for the cell fate and the direction of the cell development. PMID:15346811

  16. 5-azacytidine promotes microspore embryogenesis initiation by decreasing global DNA methylation, but prevents subsequent embryo development in rapeseed and barley.

    PubMed

    Solís, María-Teresa; El-Tantawy, Ahmed-Abdalla; Cano, Vanesa; Risueño, María C; Testillano, Pilar S

    2015-01-01

    Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypomethylation. AzaC is a useful demethylating agent to study DNA dynamics, with a potential application in microspore embryogenesis. This work analyzes the effects of short and long AzaC treatments on microspore embryogenesis initiation and progression in two species, the dicot Brassica napus and the monocot Hordeum vulgare. This involved the quantitative analyses of proembryo and embryo production, the quantification of DNA methylation, 5-methyl-deoxy-cytidine (5mdC) immunofluorescence and confocal microscopy, and the analysis of chromatin organization (condensation/decondensation) by light and electron microscopy. Four days of AzaC treatments (2.5 ?M) increased embryo induction, response associated with a decrease of DNA methylation, modified 5mdC, and heterochromatin patterns compared to untreated embryos. By contrast, longer AzaC treatments diminished embryo production. Similar effects were found in both species, indicating that DNA demethylation promotes microspore reprogramming, totipotency acquisition, and embryogenesis initiation, while embryo differentiation requires de novo DNA methylation and is prevented by AzaC. This suggests a role for DNA methylation in the repression of microspore reprogramming and possibly totipotency acquisition. Results provide new insights into the role of epigenetic modifications in microspore embryogenesis and suggest a potential benefit of inhibitors, such as AzaC, to improve the process efficiency in biotechnology and breeding programs. PMID:26161085

  17. Somatic diversification of antibody responses

    Microsoft Academic Search

    Biao Zheng; Garnett Kelsoe; Shuhua Han

    1996-01-01

    Conclusions During the last decade, a substantial body of knowledge has been obtained on the generation of somatic diversification of the B cell repertoire, especially with regard to differentiation and selection of B cells in specialized microenvironments such as GCs and GALTs which are similar to each other morphologically and physiologically. Although the mechanisms for somatic diversification remain unclear, with

  18. Epigenetic predisposition to reprogramming fates in somatic cells.

    PubMed

    Pour, Maayan; Pilzer, Inbar; Rosner, Roni; Smith, Zachary D; Meissner, Alexander; Nachman, Iftach

    2015-03-01

    Reprogramming to pluripotency is a low-efficiency process at the population level. Despite notable advances to molecularly characterize key steps, several fundamental aspects remain poorly understood, including when the potential to reprogram is first established. Here, we apply live-cell imaging combined with a novel statistical approach to infer when somatic cells become fated to generate downstream pluripotent progeny. By tracing cell lineages from several divisions before factor induction through to pluripotent colony formation, we find that pre-induction sister cells acquire similar outcomes. Namely, if one daughter cell contributes to a lineage that generates induced pluripotent stem cells (iPSCs), its paired sibling will as well. This result suggests that the potential to reprogram is predetermined within a select subpopulation of cells and heritable, at least over the short term. We also find that expanding cells over several divisions prior to factor induction does not increase the per-lineage likelihood of successful reprogramming, nor is reprogramming fate correlated to neighboring cell identity or cell-specific reprogramming factor levels. By perturbing the epigenetic state of somatic populations with Ezh2 inhibitors prior to factor induction, we successfully modulate the fraction of iPSC-forming lineages. Our results therefore suggest that reprogramming potential may in part reflect preexisting epigenetic heterogeneity that can be tuned to alter the cellular response to factor induction. PMID:25600117

  19. Non-coding RNAs as regulators of embryogenesis

    Microsoft Academic Search

    John L. Rinn; Andrea Pauli; Alexander F. Schier

    2011-01-01

    Non-coding RNAs (ncRNAs) are emerging as key regulators of embryogenesis. They control embryonic gene expression by several means, ranging from microRNA-induced degradation of mRNAs to long ncRNA-mediated modification of chromatin. Many aspects of embryogenesis seem to be controlled by ncRNAs, including the maternal–zygotic transition, the maintenance of pluripotency, the patterning of the body axes, the specification and differentiation of cell

  20. DNA sequences that activate isocitrate lyase gene expression during late embryogenesis and during postgerminative growth.

    PubMed Central

    Zhang, J Z; Santes, C M; Engel, M L; Gasser, C S; Harada, J J

    1996-01-01

    We analyzed DNA sequences that regulate the expression of an isocitrate lyase gene from Brassica napus L. during late embryogenesis and during postgerminative growth to determine whether glyoxysomal function is induced by a common mechanism at different developmental stages. beta-Glucuronidase constructs were used both in transient expression assays in B. napus and in transgenic Arabidopsis thaliana to identify the segments of the isocitrate lyase 5' flanking region that influence promoter activity. DNA sequences that play the principal role in activating the promoter during post-germinative growth are located more than 1,200 bp upstream of the gene. Distinct DNA sequences that were sufficient for high-level expression during late embryogenesis but only low-level expression during postgerminative growth were also identified. Other parts of the 5' flanking region increased promoter activity both in developing seed and in seedlings. We conclude that a combination of elements is involved in regulating the isocitrate lyase gene and that distinct DNA sequences play primary roles in activating the gene in embryos and in seedlings. These findings suggest that different signals contribute to the induction of glyoxysomal function during these two developmental stages. We also showed that some of the constructs were expressed differently in transient expression assays and in transgenic plants. PMID:8934622

  1. Characterization of conservative somatic instability of the CAG repeat region in Huntington`s disease

    SciTech Connect

    Schaefer, F.V.; Calikoglu, A.S.; Whetsell, L.H. [H.A. Chapman Research Institute of Medical Genetics, Tulsa, OK (United States)

    1994-09-01

    Instability and enlargement of a CAG repeat region at the beginning of the huntingtin gene (IT-15) has been linked with Huntington`s disease. The CAG repeat size shows a highly significant correlation with age-of-onset of clinicial features in individuals with 40 or more repeats who have Huntington disease. The clinical status of nonsymptomatic individuals with 30 to 39 CAG repeats is considered ambiguous. In order to define more carefully the nature of the HD expansion instability, we examined patients in our HD population using a discriminating fluorescence-based PCR approach. The degree of somatic mutation increases with both earlier age of onset and the size of the inherited allele. A single prominent band one repeat larger than the index peak was typical in individuals with 40-41 CAG repeats. Three to four larger bands are typically discerned in individuals with 50 or more repeats. In an extreme example, an individual with approximately 95 repeats had at least 8 prominent bands. Plotting the degree of somatic mutation relative to the size of the HD allele shows somatic mutation activity increases with size. By this approach 40-60% of the alleles in a 40-41 CAG repeat HD loci is represented in the primary allele. In contrast, the primary allele represents a relatively minor proportion of the total alleles for expansions greater than 50 CAG repeats (10-20%). The limited range of somatic mutation suggest that the instability is restricted to very early stages of embryogenesis before tissue development diverges or that persistent somatic instability occurs at a slow rate. Therefore, the properties of somatic instability in Huntington`s disease have aspects that are both in common but also different from that found in other trinucleotide repeat expanding diseases such as myotonic muscular dystrophy and fragile X syndrome.

  2. Acrolein and embryogenesis: an experimental study

    SciTech Connect

    Chhibber, G.; Cilani, S.H.

    1986-01-01

    The effects of acrolein were studied on the chick embryos of 48 and 72 hr of incubation. Acrolein was dissolved in physiological saline and injected into the air sacs of the eggs at doses ranging from 0.001 to 0.1 mg per egg. The controls received and equal amount of saline only (0.1 ml per egg). All the embryos including controls were examined at Day 13. In all, 600 eggs were utilized for this investigation. At 48 hr incubation, the percentage survival ranged from 80 to 0 as the dosage of acrolein was increased. Embryonic mortality following 72 hr incubation did not increase significantly at any dose level. Gross malformations such as short and twisted limbs, everted viscera, microphthalmia, short and twisted neck, and hemorrhage over the body were observed. The frequency and the types of gross abnormalities did not vary much in the 48- or 72-hr-treated groups. The incidence of malformation in the controls was low. The results of this study indicates that acrolein is embryotoxic at higher doses and moderately teratogenic to chick embryogenesis.

  3. Drosophila Embryogenesis Scales Uniformly across Temperature in Developmentally Diverse Species

    PubMed Central

    Kuntz, Steven G.; Eisen, Michael B.

    2014-01-01

    Temperature affects both the timing and outcome of animal development, but the detailed effects of temperature on the progress of early development have been poorly characterized. To determine the impact of temperature on the order and timing of events during Drosophila melanogaster embryogenesis, we used time-lapse imaging to track the progress of embryos from shortly after egg laying through hatching at seven precisely maintained temperatures between 17.5°C and 32.5°C. We employed a combination of automated and manual annotation to determine when 36 milestones occurred in each embryo. D. melanogaster embryogenesis takes 33 hours at 17.5°C, and accelerates with increasing temperature to a low of 16 hours at 27.5°C, above which embryogenesis slows slightly. Remarkably, while the total time of embryogenesis varies over two fold, the relative timing of events from cellularization through hatching is constant across temperatures. To further explore the relationship between temperature and embryogenesis, we expanded our analysis to cover ten additional Drosophila species of varying climatic origins. Six of these species, like D. melanogaster, are of tropical origin, and embryogenesis time at different temperatures was similar for them all. D. mojavensis, a sub-tropical fly, develops slower than the tropical species at lower temperatures, while D. virilis, a temperate fly, exhibits slower development at all temperatures. The alpine sister species D. persimilis and D. pseudoobscura develop as rapidly as tropical flies at cooler temperatures, but exhibit diminished acceleration above 22.5°C and have drastically slowed development by 30°C. Despite ranging from 13 hours for D. erecta at 30°C to 46 hours for D. virilis at 17.5°C, the relative timing of events from cellularization through hatching is constant across all species and temperatures examined here, suggesting the existence of a previously unrecognized timer controlling the progress of embryogenesis that has been tuned by natural selection as each species diverges. PMID:24762628

  4. The effect of auxin type and concentration on pecan (Carya illinoinensis) somatic embryo morphology and subsequent conversion into plants.

    PubMed

    Rodriguez, A P; Wetzstein, H Y

    1994-08-01

    Embryogenic cultures were initiated from immature pecan zygotic embryos. Explants were induced for one week on Woody Plant Medium with either ?-naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid at 2, 6 or 12 mg/l, then subcultured monthly to fresh basal medium. Observations were made on callus production, embryo formation, and embryo morphology. Somatic embryo morphology and overall callus proliferation were affected by auxin type. Callus proliferation was less extensive and more somatic embryos resembling zygotic embryos were obtained from cultures initiated with ?-naphthaleneacetic acid than with 2,4-dichlorophenoxyacetic acid. Repetitive somatic embryogenesis was obtained in all auxin treatments. Conversion into plantlets was affected by somatic embryo morphology in that embryos with poorly developed apices exhibited lower percentages of conversion than those with well developed single or multiple apices. Consequently, although more embryos were obtained with 2,4-dichlorophenoxyacetic acid, naphthaleneacetic acid was the superior auxin for production of somatic embryos more likely to convert into plants. PMID:24196238

  5. Muscle formation during embryogenesis of the polychaete Ophryotrocha diadema (Dorvilleidae) – new insights into annelid muscle patterns

    PubMed Central

    Bergter, Annette; Brubacher, John L; Paululat, Achim

    2008-01-01

    Background The standard textbook information that annelid musculature consists of oligochaete-like outer circular and inner longitudinal muscle-layers has recently been called into question by observations of a variety of complex muscle systems in numerous polychaete taxa. To clarify the ancestral muscle arrangement in this taxon, we compared myogenetic patterns during embryogenesis of Ophryotrocha diadema with available data on oligochaete and polychaete myogenesis. This work addresses the conflicting views on the ground pattern of annelids, and adds to our knowledge of the evolution of lophotrochozoan taxa. Results Somatic musculature in Ophryotrocha diadema can be classified into the trunk, prostomial/peristomial, and parapodial muscle complexes. The trunk muscles comprise strong bilateral pairs of distinct dorsal and ventral longitudinal strands. The latter are the first to differentiate during myogenesis. They originate within the peristomium and grow posteriorly through the continuous addition of myocytes. Later, the longitudinal muscles also expand anteriorly and form a complex arrangement of prostomial muscles. Four embryonic parapodia differentiate in an anterior-to-posterior progression, significantly contributing to the somatic musculature. Several diagonal and transverse muscles are present dorsally. Some of the latter are situated external to the longitudinal muscles, which implies they are homologous to the circular muscles of oligochaetes. These circular fibers are only weakly developed, and do not appear to form complete muscle circles. Conclusion Comparison of embryonic muscle patterns showed distinct similarities between myogenetic processes in Ophryotrocha diadema and those of oligochaete species, which allows us to relate the diverse adult muscle arrangements of these annelid taxa to each other. These findings provide significant clues for the interpretation of evolutionary changes in annelid musculature. PMID:18171469

  6. Somatic oxidative bioenergetics transitions into pluripotency-dependent glycolysis to facilitate nuclear reprogramming.

    PubMed

    Folmes, Clifford D L; Nelson, Timothy J; Martinez-Fernandez, Almudena; Arrell, D Kent; Lindor, Jelena Zlatkovic; Dzeja, Petras P; Ikeda, Yasuhiro; Perez-Terzic, Carmen; Terzic, Andre

    2011-08-01

    The bioenergetics of somatic dedifferentiation into induced pluripotent stem cells remains largely unknown. Here, stemness factor-mediated nuclear reprogramming reverted mitochondrial networks into cristae-poor structures. Metabolomic footprinting and fingerprinting distinguished derived pluripotent progeny from parental fibroblasts according to elevated glucose utilization and production of glycolytic end products. Temporal sampling demonstrated glycolytic gene potentiation prior to induction of pluripotent markers. Functional metamorphosis of somatic oxidative phosphorylation into acquired pluripotent glycolytic metabolism conformed to an embryonic-like archetype. Stimulation of glycolysis promoted, while blockade of glycolytic enzyme activity blunted, reprogramming efficiency. Metaboproteomics resolved upregulated glycolytic enzymes and downregulated electron transport chain complex I subunits underlying cell fate determination. Thus, the energetic infrastructure of somatic cells transitions into a required glycolytic metabotype to fuel induction of pluripotency. PMID:21803296

  7. Reprogramming somatic cells to pluripotency

    PubMed Central

    Li, Yangxin; Shen, Zhenya; Shelat, Harnath; Geng, Yong-Jian

    2013-01-01

    In 2006, Dr Shinya Yamanaka succeeded to reprogram somatic cells into pluripotent stem cells (iPSC) by delivering the genes encoding Oct4, Sox2, Klf4, and c-Myc. This achievement represents a fundamental breakthrough in stem cell biology and opens up a new era in regenerative medicine. However, the molecular processes by which somatic cells are reprogrammed into iPSC remain poorly understood. In 2009, Yamanaka proposed the elite and stochastic models for reprogramming mechanisms. To date, many investigators in the field of iPSC research support the concept of stochastic model, i.e., somatic cell reprogramming is an event of epigenetic transformation. A mathematical model, f (Cd, k), has also been proposed to predict the stochastic process. Here we wish to revisit the Yamanaka model and summarize the recent advances in this research field. PMID:24189530

  8. Comparison of somatic and sexual incompatibility between Datura innoxia and Atropa belladonna

    Microsoft Academic Search

    G. Krumbiegel; O. Schieder

    1981-01-01

    After protoplast fusion somatic hybrid calli were obtained by complementation selection between an albino mutant of Datura innoxia and the wildtype of Atropa belladonna (Krumbiegel and Schieder, 1979. Planta 145, 371–375). In the present study experiments are described concerning leaf and shoot induction on several media supplemented with different combinations and concentrations of hormones. Except for fleshy leaves and embryos,

  9. Arabidopsis transcription factor genes NF-YA1, 5, 6, and 9 play redundant roles in male gametogenesis, embryogenesis, and seed development.

    PubMed

    Mu, Jinye; Tan, Helin; Hong, Sulei; Liang, Yan; Zuo, Jianru

    2013-01-01

    Nuclear factor Y (NF-Y) is a highly conserved transcription factor presented in all eukaryotic organisms, and is a heterotrimer consisting of three subunits: NF-YA, NF-YB, and NF-YC. In Arabidopsis, these three subunits are encoded by multigene families. The best-studied member of the NF-Y transcription factors is LEAFY COTYLEDON1 (LEC1), a NF-YB family member, which plays a critical role in embryogenesis and seed maturation. However, the function of most NF-Y genes remains elusive. Here, we report the characterization of four genes in the NF-YA family. We found that a gain-of-function mutant of NF-YA1 showed defects in male gametogenesis and embryogenesis. Consistently, overexpression of NF-YA1, 5, 6, and 9 affects male gametogenesis, embryogenesis, seed morphology, and seed germination, with a stronger phenotype when overexpressing NF-YA1 and NF-YA9. Moreover, overexpression of these NF-YA genes also causes hypersensitivity to abscisic acid (ABA) during seed germination, retarded seedling growth, and late flowering at different degrees. Intriguingly, overexpression of NF-YA1, 5, 6, and 9 is sufficient to induce the formation of somatic embryos from the vegetative tissues. However, single or double mutants of these NF-YA genes do not have detectable phenotype. Collectively, these results provide evidence that NF-YA1, 5, 6, and 9 play redundant roles in male gametophyte development, embryogenesis, seed development, and post-germinative growth. PMID:22933713

  10. NO, ROS, and cell death associated with caspase-like activity increase in stress-induced microspore embryogenesis of barley

    PubMed Central

    Rodríguez-Serrano, María; Bárány, Ivett; Prem, Deepak; Coronado, María-José; Risueño, María C.; Testillano, Pilar S.

    2012-01-01

    Under specific stress treatments (cold, starvation), in vitro microspores can be induced to deviate from their gametophytic development and switch to embryogenesis, forming haploid embryos and homozygous breeding lines in a short period of time. The inductive stress produces reactive oxygen species (ROS) and nitric oxide (NO), signalling molecules mediating cellular responses, and cell death, modifying the embryogenic microspore response and therefore, the efficiency of the process. This work analysed cell death, caspase 3-like activity, and ROS and NO production (using fluorescence probes and confocal analysis) after inductive stress in barley microspore cultures and embryogenic suspension cultures, as an in vitro system which permitted easy handling for comparison. There was an increase in caspase 3-like activity and cell death after stress treatment in microspore and suspension cultures, while ROS increased in non-induced microspores and suspension cultures. Treatments of the cultures with a caspase 3 inhibitor, DEVD-CHO, significantly reduced the cell death percentages. Stress-treated embryogenic suspension cultures exhibited high NO signals and cell death, while treatment with S-nitrosoglutathione (NO donor) in control suspension cultures resulted in even higher cell death. In contrast, in microspore cultures, NO production was detected after stress, and, in the case of 4-day microspore cultures, in embryogenic microspores accompanying the initiation of cell divisions. Subsequent treatments of stress-treated microspore cultures with ROS and NO scavengers resulted in a decreasing cell death during the early stages, but later they produced a delay in embryo development as well as a decrease in the percentage of embryogenesis in microspores. Results showed that the ROS increase was involved in the stress-induced programmed cell death occurring at early stages in both non-induced microspores and embryogenic suspension cultures; whereas NO played a dual role after stress in the two in vitro systems, one involved in programmed cell death in embryogenic suspension cultures and the other in the initiation of cell division leading to embryogenesis in reprogrammed microspores. PMID:22197894

  11. ERECTA family genes regulate development of cotyledons during embryogenesis.

    PubMed

    Chen, Ming-Kun; Shpak, Elena D

    2014-11-01

    Receptor-like kinases are important regulators of plant growth. Often a single receptor is involved in regulation of multiple developmental processes in a variety of tissues. ERECTA family (ERf) receptors have previously been linked with stomata development, above-ground organ elongation, shoot apical meristem function, flower differentiation and biotic/abiotic stresses. Here we explore the role of these genes during embryogenesis. ERfs are expressed in the developing embryo, where their expression is progressively limited to the upper half of the embryo. During embryogenesis ERfs redundantly stimulate the growth of cotyledons by promoting cell proliferation and inhibiting premature stomata differentiation. PMID:25240196

  12. Bovine somatic cell nuclear transfer.

    PubMed

    Ross, Pablo J; Cibelli, Jose B

    2010-01-01

    Somatic cell nuclear transfer (SCNT) is a technique by which the nucleus of a differentiated cell is introduced into an oocyte from which its genetic material has been removed by a process called enucleation. In mammals, the reconstructed embryo is artificially induced to initiate embryonic development (activation). The oocyte turns the somatic cell nucleus into an embryonic nucleus. This process is called nuclear reprogramming and involves an important change of cell fate, by which the somatic cell nucleus becomes capable of generating all the cell types required for the formation of a new individual, including extraembryonic tissues. Therefore, after transfer of a cloned embryo to a surrogate mother, an offspring genetically identical to the animal from which the somatic cells where isolated, is born. Cloning by nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. Cattle were the second mammalian species to be cloned after Dolly the sheep, and it is probably the most widely used species for SCNT experiments. This is, in part due to the high availability of bovine oocytes and the relatively higher efficiency levels usually obtained in cattle. Given the wide utilization of this species for cloning, several alternatives to this basic protocol can be found in the literature. Here we describe a basic protocol for bovine SCNT currently being used in our laboratory, which is amenable for the use of the nuclear transplantation technique for research or commercial purposes. PMID:20336522

  13. Somatic Treatments for Mood Disorders

    Microsoft Academic Search

    Moacyr A Rosa; Sarah H Lisanby

    2012-01-01

    Somatic treatments for mood disorders represent a class of interventions available either as a stand-alone option, or in combination with psychopharmacology and\\/or psychotherapy. Here, we review the currently available techniques, including those already in clinical use and those still under research. Techniques are grouped into the following categories: (1) seizure therapies, including electroconvulsive therapy and magnetic seizure therapy, (2) noninvasive

  14. Somatic variation in Lolium perenne

    Microsoft Academic Search

    Y Shimamoto; M D Hayward

    1975-01-01

    An investigation of somatic variation in 10 plants of Lolium perenne, using a two-stage cloning process followed by two further cycles of vegetative propagation, has revealed that persistent differences in tiller number and plant height may arise at the time of the initial cloning. These effects were dependent upon the age of the clone and its past vegetative history. Transmissibility

  15. INTRODUCTION During early Drosophila embryogenesis, a number of

    E-print Network

    Patel, Nipam H.

    INTRODUCTION During early Drosophila embryogenesis, a number of developmental programs unfold and Nüsslein-Vol- hard, 1988; reviewed by Govind and Steward, 1991). Later, during germ band extension the ectoderm give rise to about 250 neurons. During germ band retraction, the CNS continues to differentiate

  16. Introduction Building tissues and organs during embryogenesis involves a

    E-print Network

    Parkhurst, Susan

    (reviewed by Grinnell, 1992; Martin, 1997; Werner and Grose, 2003). The deeper connective tissue is replaced of collagen within the healed connective tissue. Tissue repair in the mouse embryo involves largely the same3021 Introduction Building tissues and organs during embryogenesis involves a series of exquisite

  17. Early events leading to fate decisions during leech embryogenesis

    E-print Network

    Weisblat, David A.

    Early events leading to fate decisions during leech embryogenesis Marc Pilon and David A. Weisblat This paper reviews leech development up to the 12-cell embryo. Oogenesis proceeds by a system of nurse cells-nos, a leech homolog to the Drosophila gene nanos, suggests that it may be a determinant associated

  18. Somatic Mutation, Genomic Variation, and Neurological Disease

    PubMed Central

    Poduri, Annapurna; Evrony, Gilad D.; Cai, Xuyu; Walsh, Christopher A.

    2014-01-01

    Genetic mutations causing human disease are conventionally thought to be inherited through the germ line from one’s parents and present in all somatic (body) cells, except for most cancer mutations, which arise somatically. Increasingly, somatic mutations are being identified in diseases other than cancer, including neurodevelopmental diseases. Somatic mutations can arise during the course of prenatal brain development and cause neurological disease—even when present at low levels of mosaicism, for example—resulting in brain malformations associated with epilepsy and intellectual disability. Novel, highly sensitive technologies will allow more accurate evaluation of somatic mutations in neurodevelopmental disorders and during normal brain development. PMID:23828942

  19. Integration and expression of Bluetongue VP2 gene in somatic embryos of peanut through particle bombardment method.

    PubMed

    Athmaram, T N; Bali, Geetha; Devaiah, K M

    2006-04-01

    After pre-culture and treatment of osmosis, zygotic embryos of peanut (Arachis hypogaea L.) were transformed via particle bombardment with a plasmid containing a Bluetongue VP2 gene (BTVP2) comprising neutralizing epitopes. Selection for Kanamycin resistant calluses and somatic embryos was initiated at 12th day post-bombardment on medium containing 25 mg/L Kanamycin. Under continuous selection, 12.38% Kanamycin resistant plantlets were regenerated from bombarded somatic embryos. The presence and integration of BTVP2 DNA in regenerated Kanamycin resistant plants were confirmed by southern hybridization assay using non-radioactive Digoxiginin BTVP2 probe. Beta-glucuronidase (GUS) enzyme activity was detected in transgenic somatic embryos but not from control, non-transformed embryos. The expression of the BTVP2 protein was confirmed through RT-PCR (reverse transcription polymerase chain reaction) using the RNA isolated from the transgenic callus employing BTVP2-specific primers. The production of transgenic peanut was mainly focused on evaluating a newly improved somatic embryogenesis regeneration system as well as the gene transfer method and to produce the Bluetongue outer coat protein that comprises the neutralizing epitopes. PMID:16513222

  20. Comparative transcriptome analysis between somatic embryos (SEs) and zygotic embryos in cotton: evidence for stress response functions in SE development.

    PubMed

    Jin, Fangyan; Hu, Lisong; Yuan, Daojun; Xu, Jiao; Gao, Wenhui; He, Liangrong; Yang, Xiyan; Zhang, Xianlong

    2014-02-01

    As a product of asexual reproduction in plants, the somatic embryo (SE) differentiates into a new plantlet via a zygotic embryogenesis-like process. Here, we present the phenotypic and cellular differences between SEs and zygotic embryos (ZEs) revealed by histological section scanning using three parallel development stages of the two types of embryos of cotton (Gossypium hirsutum cv. YZ1), including globular, torpedo and cotyledonary-stages. To identify the molecular characteristics of SE development in cotton, the digital gene expression system was used to profile the genes active during SE and ZE development. A total of 4242 differentially expressed genes (DEGs) were identified in at least one developmental stage. Expression pattern and functional classification analysis based on these DEGs reveals that SE development exhibits a transcriptional activation of stress responses. RT-PCR analysis further confirmed enhanced expression levels of stress-related genes in SEs than in ZEs. Experimental stress treatment, induced by NaCl and ABA, accelerated SE development and increased the transcription of genes related to stress response, in parallel with decelerated proliferation of embryogenic calluses under stress treatment. Our data reveal that SE development involves the activation of stress responses, which we suggest may regulate the balance between cell proliferation and differentiation. These results provide new insight into the molecular mechanisms of SE development and suggest strategies that can be used for regulating the developmental processes of somatic embryogenesis. PMID:24112122

  1. Somatic Cell Counts in Holsteins

    Microsoft Academic Search

    B. W. KENNEDY; M. S. SETHAR; A. K. W. TONG; J. E. MOXLEY; B. R. DOWNEY; Dairy Herd

    Between February and December, 1977, 133,493 test-day observations of somatic cell count were taken on 27,009 Holstein cows in 676 herds on the Quebec Dairy Herd Analysis Service. Data were transformed to a log (natural) scale, and analyses were separate within lacta- tion age group (42, 3, 4, 5, and \\/>6 yr). Joint estimates of fixed effects of month of

  2. Neural induction in Xenopus requires inhibition of Wnt-?-catenin signaling

    Microsoft Academic Search

    Elizabeth Heeg-Truesdell; Carole LaBonne

    2006-01-01

    Canonical Wnt signals have been implicated in multiple events during early embryogenesis, including primary axis formation, neural crest induction, and A–P patterning of the neural plate. The mechanisms by which Wnt signals can direct distinct fates in cell types that are closely linked both temporally and spatially remains poorly understood. However, recent work has suggested that the downstream transcriptional mediators

  3. Attachment in romantic relationships and somatization.

    PubMed

    Neumann, Eva; Sattel, Heribert; Gündel, Harald; Henningsen, Peter; Kruse, Johannes

    2015-02-01

    Adult attachment representations have been considered to play a role in the development and treatment of somatizing behavior. In this study, the associations between the two attachment dimensions avoidance and anxiety and dimensions of psychopathology (somatization, depression, and general anxiety) were explored. The sample consists of 202 outpatients diagnosed with a somatoform disorder. Data were collected via self-report measures. A path analysis shows that the two attachment dimensions are not directly associated with somatization. There are, however, significant indirect associations between attachment and somatization mediated by depression and general anxiety, which are more pronounced for attachment anxiety than for attachment avoidance. The findings reveal that a low level of attachment security in romantic relationships, especially an anxious stance toward the partner, comes along with poor mental health, which in turn is related to a preoccupation with somatic complaints. Implications for the treatment of somatizing patients are discussed. PMID:25594785

  4. Differential tissue development during embryogenesis and regeneration in an Annelid.

    PubMed

    Myohara, Maroko

    2004-10-01

    The fragmenting potworm Enchytraeus japonensis (Oligochaeta, Annelida) reproduces asexually by dividing the body into several fragments that then regenerate to complete individuals in 4-5 days. Such large-scale regeneration, however, occurs only in some invertebrates. To better our understanding of why regeneration is so limited in many animals, despite their ability to undergo embryonic development from the single cell of a fertilized egg, comparisons were made between regeneration and embryonic development of E. japonensis by using two methods: histochemistry for alkaline phosphatase (ALP) and immunohistochemistry with an antibody against acetylated tubulin that visualizes nervous system development. The analyses revealed that both ALP expression patterns and central nervous system development differ between embryogenesis and the regeneration, suggesting that regeneration is not a simple reiteration of embryogenesis but involves different regulatory mechanisms. The study provides a basis for the elucidation of mechanisms that are unique and crucial to regeneration. PMID:15366012

  5. Cracking the egg: virtual embryogenesis of real robots.

    PubMed

    Cussat-Blanc, Sylvain; Pollack, Jordan

    2014-01-01

    All multicellular living beings are created from a single cell. A developmental process, called embryogenesis, takes this first fertilized cell down a complex path of reproduction, migration, and specialization into a complex organism adapted to its environment. In most cases, the first steps of the embryogenesis take place in a protected environment such as in an egg or in utero. Starting from this observation, we propose a new approach to the generation of real robots, strongly inspired by living systems. Our robots are composed of tens of specialized cells, grown from a single cell using a bio-inspired virtual developmental process. Virtual cells, controlled by gene regulatory networks, divide, migrate, and specialize to produce the robot's body plan (morphology), and then the robot is manually built from this plan. Because the robot is as easy to assemble as Lego, the building process could be easily automated. PMID:24730763

  6. Non-coding RNAs as regulators of embryogenesis

    PubMed Central

    Pauli, Andrea; Rinn, John L.; Schier, Alexander F.

    2014-01-01

    Non-coding RNAs (ncRNAs) are emerging as key regulators of embryogenesis. They control embryonic gene expression by several means, ranging from microRNA-induced degradation of mRNAs to long ncRNA-mediated modification of chromatin. Many aspects of embryogenesis seem to be controlled by ncRNAs, including the maternal–zygotic transition, the maintenance of pluripotency, the patterning of the body axes, the specification and differentiation of cell types and the morphogenesis of organs. Drawing from several animal model systems, we describe two emerging themes for ncRNA function: promoting developmental transitions and maintaining developmental states. These examples also highlight the roles of ncRNAs in ensuring a robust commitment to one of two possible cell fates. PMID:21245830

  7. Axes, planes and tubes, or the geometry of embryogenesis

    Microsoft Academic Search

    Sabine Brauckmann

    2011-01-01

    The paper presents selected figures of chick embryogenesis as depicted in the classic studies of Caspar Friedrich Wolff (1734–1794), Christian Heinrich Pander (1794–1865) and Karl Ernst von Baer (1792–1786). My main objective here is (1) to demonstrate how the imagery of Wolff, Pander and Baer attempted to project an image of a 3-dimensional rotating body into static figures on paper

  8. The Genetic and Epigenetic Contributions of Sperm to Early Embryogenesis

    Microsoft Academic Search

    Denny Sakkas; Maria Lalioti; Hasan M. El-Fakahany; Emre Seli

    \\u000a During fertilization, the sperm delivers a haploid set of chromosomes to the zygote. Genetic alterations, such as numerical\\u000a or structural chromosome defects, can affect the ability of the embryo to undergo normal development. Similarly, epigenetic\\u000a defects, such as abnormal methylation of gene promoters, may affect gene expression during embryogenesis and affect the viability\\u000a or health of the developing embryo. This

  9. TOPLESS Mediates Auxin-Dependent Transcriptional Repression During Arabidopsis Embryogenesis

    Microsoft Academic Search

    Heidi Szemenyei; Mike Hannon; Jeff A. Long

    2008-01-01

    The transcriptional response to auxin is critical for root and vascular development during Arabidopsis embryogenesis. Auxin induces the degradation of AUXIN\\/INDOLE-3-ACETIC ACID (AUX\\/IAA) transcriptional repressors, freeing their binding partners, the AUXIN RESPONSE FACTOR (ARF) proteins, which can activate transcription of auxin response genes. We show that TOPLESS (TPL) can physically interact with IAA12\\/BODENLOS (IAA12\\/BDL) through an ETHYLENE RESPONSE FACTOR (ERF)-associated

  10. Expression and cellular localization of Atrab28 during Arabidopsis embryogenesis

    Microsoft Academic Search

    César Arenas-Mena; Monique Raynal; Antonio Borrell; Fabrice Varoquaux; Mari Cruz Cutanda; Robin A. P. Stacy; Montserrat Pagès; Michel Delseny; Francisco A. Culiáñez-Macià

    1999-01-01

    The maize abscisic acid (ABA)-responsive gene rab28 has been shown to be ABA-inducible in embryos and vegetative tissues, expression being mostly restricted to vascular elements during late embryogenesis. In the course of an expressed sequence tags (ESTs) programme, we have isolated an Arabidopsis thaliana gene, Atrab28, encoding the orthologue of maize rab28. The Atrab28 cDNA is 1090 bp long, including a

  11. Interactions between ?-tocopherol, polyunsaturated fatty acids, and lipoxygenases during embryogenesis.

    PubMed

    Lebold, Katie M; Traber, Maret G

    2014-01-01

    ?-Tocopherol is a lipid-soluble antioxidant that is specifically required for reproduction and embryogenesis. However, since its discovery, ?-tocopherol's specific biologic functions, other than as an antioxidant, and the mechanism(s) mediating its requirement for embryogenesis remain unknown. As an antioxidant, ?-tocopherol protects polyunsaturated fatty acids (PUFAs) from lipid peroxidation. ?-Tocopherol is probably required during embryonic development to protect PUFAs that are crucial to development, specifically arachidonic (ARA) and docosahexaenoic (DHA) acids. Additionally, ARA and DHA are metabolized to bioactive lipid mediators via lipoxygenase enzymes, and ?-tocopherol may directly protect, or it may mediate the production and/or actions of, these lipid mediators. In this review, we discuss how ?-tocopherol (1) prevents the nonspecific, radical-mediated peroxidation of PUFAs, (2) functions within a greater antioxidant network to modulate the production and/or function of lipid mediators derived from 12- and 12/15-lipoxygenases, and (3) modulates 5-lipoxygenase activity. The application and implication of such interactions are discussed in the context of ?-tocopherol requirements during embryogenesis. PMID:23920314

  12. RNA-editing cytidine deaminase Apobec-1 is unable to induce somatic hypermutation in mammalian cells

    PubMed Central

    Eto, Tomonori; Kinoshita, Kazuo; Yoshikawa, Kiyotsugu; Muramatsu, Masamichi; Honjo, Tasuku

    2003-01-01

    Antibody diversification by somatic hypermutation, gene conversion, and class switch recombination is completely dependent on activation-induced cytidine deaminase (AID). A recent report showing induction of DNA mutations in Escherichia coli by overexpression of AID, Apobec-1, and related members of the RNA-editing cytidine deaminase family suggested that they may directly modify deoxycytidine in DNA in mammalian cells (DNA-editing model). We therefore examined whether Apobec-1 bona fide RNA-editing enzyme could show somatic hypermutation and class switching activities in murine B lymphocytes and fibroblasts. Unlike AID, Apobec-1 was unable to induce somatic hypermutation or class switching. The results force a reevaluation of the physiological significance of the DNA deaminase activities of AID and Apobec-1 in E. coli and in vitro. PMID:14559972

  13. Regeneration of somatic embryos in Theobroma cacao L. in temporary immersion bioreactor and analyses of free amino acids in different tissues.

    PubMed

    Niemenak, Nicolas; Saare-Surminski, Katja; Rohsius, Christina; Ndoumou, Denis Omokolo; Lieberei, Reinhard

    2008-04-01

    The present study aimed at developing temporary immersion bioreactor techniques for multiplication of cacao somatic embryos. Temporary Immersion System (TIS), i.e. flooding of plant tissue at regular time intervals provides an efficient way to propagate plants. Somatic embryos were regenerated in twin flask bioreactors. The TIS proved to be suitable for mass regeneration of somatic embryos and for their subsequent direct sowing. The number of embryos after 3 months of culture was significantly higher in TIS cultures than in the solid medium variant. TIS also improved embryo development regarding the conversion to torpedo shaped forms. Matured embryos derived from TIS and pre-treated with 6% sucrose were converted into plants after direct sowing. Additionally to the influence of culture conditions on the development of somatic embryogenesis the content and composition of free amino acids were analysed. The content of free amino acids in somatic embryos rose as immersion frequency increased. The endogenous free GABA content in embryogenic callus was significantly higher than in non-embryogenic callus. PMID:18193427

  14. Rapid and efficient transformation of diploid Medicago truncatula and Medicago sativa ssp. falcata lines improved in somatic embryogenesis

    Microsoft Academic Search

    T. H. Trinh; P. Ratet; E. Kondorosi; P. Durand; K. Kamaté; P. Bauer; A. Kondorosi

    1998-01-01

    We describe a simple and efficient protocol for regeneration-transformation of two diploid Medicago lines: the annual M. truncatula R108-1(c3) and the perennial M. sativa ssp. falcata (L.) Arcangeli PI.564263 selected previously as highly embryogenic genotypes. Here, embryo regeneration of R108-1 to complete\\u000a plants was further improved by three successive in vitro regeneration cycles resulting in the line R108-1(c3). Agrobacterium tumefaciens-mediated

  15. Effect of 2,4-dichlorophenoxyacetic acid concentration on somatic embryogenesis and heritable variation in soybean [ Glycine max (L) merr.

    Microsoft Academic Search

    Randy C. Shoemaker; Laurie A. Amberger; Reid G. Palmer; Lynnea Oglesby; Jerome P. Ranch

    1991-01-01

    Summary  The frequency and quality of embryogenic response from cotyledons of immature zygotic soybean embryos varied with 2,4-dichlorophenoxyacetic\\u000a acid (2,4-D) concentration in the culture medium. The frequency of variants among progeny of regenerated plants decreased\\u000a with an increase of 2,4-D concentration. Teratogenic effects on embryo morphology and development were greatest at 22.5µM 2,4-D and decreased with increasing 2,4-D. At the lowest

  16. Plant regeneration through somatic embryogenesis in root-derived callus of ginseng ( Panax ginseng C. A. Meyer)

    Microsoft Academic Search

    W. C. Chang; Y. I. Hsing

    1980-01-01

    Callus culture was initiated from expiants of mature root tissues of ginseng (Panax ginseng C.A. Meyer) on MS medium enriched with 2,4-D. The ageing callus produced numerous embryoids in this medium. Reculture of these embryoids in media (1\\/2 MS or B5) supplemented with benzyladenine and gibberellic acid resulted in profuse plantlet regeneration.

  17. Cryopreservation of plumular explants of coconut (Cocos nucifera L.) to support programmes for mass clonal propagation through somatic embryogenesis.

    PubMed

    Hornung, R; Domas, R; Lynch, P T

    2001-01-01

    Callus growth has been observed from plumules of ecotype Laguna Tall after cryopreservation using an encapsulation/dehydration protocol. Sucrose preculture treatment and silica gel dehydration both significantly influenced the frequency of callus formation from non-frozen and frozen plumules. The greatest frequency of post-thaw callus growth occurred after incubation of the encapsulated plumules for 72-96 h in medium containing 0.75 M sucrose followed by desiccation over silica gel for 7-8 h down to approximately 30% moisture content (fresh weight basis). Freezing and thawing were carried out rapidly. Post-thaw recovery rates in excess of 80% were recorded. PMID:11788861

  18. Detection of somaclonal variation during cocoa somatic embryogenesis characterised using cleaved amplified polymorphic sequence and the new freeware Artbio

    Microsoft Academic Search

    Carlos M. Rodríguez López; Hector Sicilia Bravo; Andrew C. Wetten; Michael J. Wilkinson

    2010-01-01

    The scarcity and stochastic nature of genetic mutations presents a significant challenge for scientists seeking to characterise\\u000a de novo mutation frequency at specific loci. Such mutations can be particularly numerous during regeneration of plants from\\u000a in vitro culture and can undermine the value of germplasm conservation efforts. We used cleaved amplified polymorphic sequence\\u000a (CAPS) analysis to characterise new mutations amongst

  19. The role of Somatic embryogenesis receptor-like kinase 1 in controlling pollen production of the Gossypium anther.

    PubMed

    Shi, Ya-li; Guo, San-dui; Zhang, Rui; Meng, Zhi-gang; Ren, Mao-zhi

    2014-01-01

    In flowering plants, male gametophytes are generated in anthers from microsporocytes. However, more evidence is needed to reveal the genetic mechanisms which regulate the differentiation and interaction of these highly specialized cells in anthers. Here we report the characterization of a series of male-sterile cotton (Gossypium hirsutum) mutants, including mutants with normal fertility, semi-sterility and complete sterility. These mutants are forms of transgenic cotton containing RNAi vectors with partial cDNA fragments of GhSERK1. The GhSERK1 gene encodes a putative leucine-rich repeat receptor protein kinase (LRR-RLK), and generally has 11 domains. In previous research, we found plants containing GhSERK1 produce an abundance of male reproductive tissue. In this paper, three RNAi constructs were designed separately to analyze its function in anther. After the three RNAi vectors were transformed into the cotton, transgenic plants with the specialized fragment exhibited normal fertility or the pollen energy decreased slightly, as ones with the homologous fragments exhibited various degrees of male sterility with different expression levels of GhSERK1 mRNA. In conclusion, for the transgenic plants with conserved fragments, lower expression levels of GhSERK1 mRNA were in transgenic plants, and a higher degree of male sterility was observed. Taking together, these findings demonstrate the GhSERK1 gene has a role in the development of anthers, especially in the formation of pollen grains. Also, we infer there must be another homolog of GhSERK1 in cotton, and both of GhSERK1 and its homolog function redundantly as important control points in controlling anther pollen production. PMID:24276918

  20. The effect of several factors on somatic embryogenesis and plant regeneration in protoplast cultures of Gentiana kurroo (Royle)

    Microsoft Academic Search

    Agnieszka Fiuk; Jan J. Rybczy?ski

    2007-01-01

    Protoplasts were isolated from cell suspensions derived from cotyledon and hypocotyl Gentiana kurroo (Royle). Cell walls were digested with an enzyme cocktail containing cellulase, macerozyme, driselase, hemicellulase and\\u000a pectolyase in CPW solution. Protoplast viability ranged from 88 to 96%. Three techniques of culture and six media were evaluated\\u000a in terms of their efficiency in producing viable cultures and regenerating whole

  1. Genotype and auxin influence direct somatic embryogenesis from protoplasts derived from embryogenic cell suspensions of Asparagus officinalis L

    Microsoft Academic Search

    Roger A. May; Kenneth C. Sink

    1995-01-01

    Embryogenic callus from four asparagus genotypes, Jersey Giant No. 8, MD10, Rutgers 22, and 86SOM1 was simultaneously initiated from spear explants on semisolid LS medium containing 5 ?M 2,4-D or 50 ?M NAA. Calluses were used to initiate cell suspensions in liquid LS medium of the same composition. The eight sets of cell suspensions were used as protoplast donors at

  2. Attachment and interpersonal communication in somatization

    Microsoft Academic Search

    SCOTT STUART; RUSSELL NOYES

    1999-01-01

    The authors review the research on childhood antecedents and personality contributions to the somatoform disorders, as well as research on social influences during adulthood. Based on these data, the authors hypothesize that somatizing patients display anxious attachment behavior that derives from childhood experiences with caregivers. Early exposure to illness increases the likeli- hood that distress will be manifested somatically. When

  3. Somatic Mosaicism in the Human Genome

    PubMed Central

    Freed, Donald; Stevens, Eric L.; Pevsner, Jonathan

    2014-01-01

    Somatic mosaicism refers to the occurrence of two genetically distinct populations of cells within an individual, derived from a postzygotic mutation. In contrast to inherited mutations, somatic mosaic mutations may affect only a portion of the body and are not transmitted to progeny. These mutations affect varying genomic sizes ranging from single nucleotides to entire chromosomes and have been implicated in disease, most prominently cancer. The phenotypic consequences of somatic mosaicism are dependent upon many factors including the developmental time at which the mutation occurs, the areas of the body that are affected, and the pathophysiological effect(s) of the mutation. The advent of second-generation sequencing technologies has augmented existing array-based and cytogenetic approaches for the identification of somatic mutations. We outline the strengths and weaknesses of these techniques and highlight recent insights into the role of somatic mosaicism in causing cancer, neurodegenerative, monogenic, and complex disease. PMID:25513881

  4. Cytogenetic effects of inhaled ethylene oxide in somatic and germ cells of mice

    Microsoft Academic Search

    Lficia Regina Ribeiro; Maria Nazareth Rabello-Gay; Daisy Maria Fávero Salvadori; Carlos Alberto Bragança Pereira; Willy Beçak

    1987-01-01

    The induction of cytogenetic effects by inhalation of ethylene oxide was tested in bone marrow cells and primary spermatocytes at diakinesis-metaphase I cells from mouse after a single treatment (6 h\\/1 day) at 0, 200, 400 and 600 ppm, and multiple treatment (6 h\\/5 days\\/2 weeks) at 0, 200 and 400 ppm. Ethylene oxide induced chromosomal aberrations in both somatic

  5. Histological events leading to somatic embryo formation in cultured petioles of alfalfa

    Microsoft Academic Search

    C. L. Wenzel; D. C. W. Brown

    1991-01-01

    Summary  An optimum 10-day exposure of petioles of alfalfa [Medicago sativa ssp.falcata (L.) Arcangeli] to 2,4-dichlorophenoxyacetic acid or 2,4,5-trichlorophenoxyacetic acid results in the semisynchronous production\\u000a of somatic embryos starting about 4 days after transfer to a non-auxin-containing medium. The timing of cell division induction\\u000a in the petiole explants was found to vary depending on the petiole tissue type. Cells adjacent to

  6. Somatic mosaicism of a novel IKBKG mutation in a male patient with incontinentia pigmenti.

    PubMed

    Hull, Sarah; Arno, Gavin; Thomson, Penelope; Mutch, Stacey; Webster, Andrew R; Rai, Harjeet; Hill, Virginia; Moore, Anthony T

    2015-07-01

    Incontinentia pigmenti (IP) is an X-linked, dominant genodermatosis usually fatal in utero in males. In rare circumstances, survival is possible due to abnormal karyotype or somatic mosaicism. In this report, the mechanism and significance of loss of detectable mutation in peripheral blood leukocytes of a somatic mosaic male is discussed and an alternative approach to achieving molecular diagnosis presented. A male patient is reported, who initially presented at 2 days of age with a rash and seizure. Clinical assessment and histology of a skin biopsy were consistent with a diagnosis of IP. He was subsequently found to have bilateral retinal detachments. Screening for the common deletion in IKBKG was negative. A novel nonsense variant, c.937C>T (p.Gln313*) in IKBKG was identified at an approximate level of 15% in a blood sample taken at 10 days of age, but was undetectable in a sample taken at 3 years most likely due to selective apoptosis of mutant cells. Samples taken from the patient when he was 5-6 years of age identified the mutation at a low level in hair root and urine but not in blood or buccal cells. The detection of the mutation in cells derived from all germ layers indicates a de novo event at an early stage of embryogenesis. This is the first report of a nonsense mutation in a male IP patient. © 2015 Wiley Periodicals, Inc. PMID:25944529

  7. Early Zebrafish Embryogenesis Is Susceptible to Developmental TDCPP Exposure

    PubMed Central

    McGee, Sean P.; Cooper, Ellen M.; Stapleton, Heather M.

    2012-01-01

    Background: Chlorinated phosphate esters (CPEs) are widely used as additive flame retardants for low-density polyurethane foams and have frequently been detected at elevated concentrations within indoor environmental media. Objectives: To begin characterizing the potential toxicity of CPEs on early vertebrate development, we examined the developmental toxicity of four CPEs used in polyurethane foam: tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and 2,2-bis(chloromethyl)propane-1,3-diyl tetrakis(2-chlorethyl) bis(phosphate) (V6). Methods: Using zebrafish as a model for vertebrate embryogenesis, we first screened the potential teratogenic effects of TDCPP, TCEP, TCPP, and V6 using a developmental toxicity assay. Based on these results, we focused on identification of susceptible windows of developmental TDCPP exposure as well as evaluation of uptake and elimination of TDCPP and bis(1,3-dichloro-2-propyl)phosphate (BDCPP, the primary metabolite) within whole embryos. Finally, because TDCPP-specific genotoxicity assays have, for the most part, been negative in vivo and because zygotic genome remethylation is a key biological event during cleavage, we investigated whether TDCPP altered the status of zygotic genome methylation during early zebrafish embryogenesis. Results: Overall, our findings suggest that the cleavage period during zebrafish embryogenesis is susceptible to TDCPP-induced delays in remethylation of the zygotic genome, a mechanism that may be associated with enhanced developmental toxicity following initiation of TDCPP exposure at the start of cleavage. Conclusions: Our results suggest that further research is needed to better understand the effects of a widely used and detected CPE within susceptible windows of early vertebrate development. PMID:23017583

  8. Systematic identification of long noncoding RNAs expressed during zebrafish embryogenesis

    PubMed Central

    Pauli, Andrea; Valen, Eivind; Lin, Michael F.; Garber, Manuel; Vastenhouw, Nadine L.; Levin, Joshua Z.; Fan, Lin; Sandelin, Albin; Rinn, John L.; Regev, Aviv; Schier, Alexander F.

    2012-01-01

    Long noncoding RNAs (lncRNAs) comprise a diverse class of transcripts that structurally resemble mRNAs but do not encode proteins. Recent genome-wide studies in humans and the mouse have annotated lncRNAs expressed in cell lines and adult tissues, but a systematic analysis of lncRNAs expressed during vertebrate embryogenesis has been elusive. To identify lncRNAs with potential functions in vertebrate embryogenesis, we performed a time-series of RNA-seq experiments at eight stages during early zebrafish development. We reconstructed 56,535 high-confidence transcripts in 28,912 loci, recovering the vast majority of expressed RefSeq transcripts while identifying thousands of novel isoforms and expressed loci. We defined a stringent set of 1133 noncoding multi-exonic transcripts expressed during embryogenesis. These include long intergenic ncRNAs (lincRNAs), intronic overlapping lncRNAs, exonic antisense overlapping lncRNAs, and precursors for small RNAs (sRNAs). Zebrafish lncRNAs share many of the characteristics of their mammalian counterparts: relatively short length, low exon number, low expression, and conservation levels comparable to that of introns. Subsets of lncRNAs carry chromatin signatures characteristic of genes with developmental functions. The temporal expression profile of lncRNAs revealed two novel properties: lncRNAs are expressed in narrower time windows than are protein-coding genes and are specifically enriched in early-stage embryos. In addition, several lncRNAs show tissue-specific expression and distinct subcellular localization patterns. Integrative computational analyses associated individual lncRNAs with specific pathways and functions, ranging from cell cycle regulation to morphogenesis. Our study provides the first systematic identification of lncRNAs in a vertebrate embryo and forms the foundation for future genetic, genomic, and evolutionary studies. PMID:22110045

  9. Comparison of developmental trajectories in the starlet sea anemone Nematostella vectensis: embryogenesis, regeneration,

    E-print Network

    Finnerty, John R.

    reproduction, (2) asexual reproduction via physal pinching, (3) asexual reproduction via polarity reversal sequences of embryogenesis, asexual reproduction, and regenera- tion have not been explicitly compared: embryogenesis, regeneration, and two forms of asexual fission Adam M. Reitzel, Patrick M. Burton, Cassandra

  10. Cytokinin and auxin interaction in root stem-cell specification during early embryogenesis

    E-print Network

    Sheen, Jen

    LETTERS Cytokinin and auxin interaction in root stem-cell specification during early embryogenesis embryogenesis2,3 , but the early embryonic function of cytokinin is obscure4­6 . Here, we introduce a synthetic reporter to visualize universally cytokinin output in vivo. Notably, the first embryonic signal is detected

  11. Monitoring udder health and milk quality using somatic cell counts

    Microsoft Academic Search

    Ynte H. Schukken; David J. Wilson; Francis Welcome; Linda Garrison-Tikofsky; Ruben N. Gonzalez

    2003-01-01

    In this article the use of somatic cell counts for monitoring udder health and milk quality is discussed. Somatic cell count dynamics at quarter, cow, herd and population level are discussed and illustrated with examples. Quarter and cow somatic cell counts directly represent the inflammatory status of the mammary gland. Herd and population somatic cell count are related to the

  12. Somatic Symptoms and Anxiety Among African American Adolescents

    Microsoft Academic Search

    Julie Newman Kingery; Golda S. Ginsburg; Candice A. Alfano

    2007-01-01

    Somatic symptoms are an associated feature of anxiety disorders that have received little research attention among non-White samples. In addition, the majority of previous studies have examined the influence of somatic symptoms in a cross-sectional rather than a prospective manner. This study examines the prevalence of 12 somatic symptoms, the association of somatic and anxiety symptoms (both concurrently and prospectively)

  13. Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

    PubMed Central

    Boyd, Lynn; Hajjar, Connie; O'Connell, Kevin

    2011-01-01

    Caenorhabditis elegans has often been used as a model system in studies of early developmental processes. The transparency of the embryos, the genetic resources, and the relative ease of transformation are qualities that make C. elegans an excellent model for early embryogenesis. Laser-based confocal microscopy and fluorescently labeled tags allow researchers to follow specific cellular structures and proteins in the developing embryo. For example, one can follow specific organelles, such as lysosomes or mitochondria, using fluorescently labeled dyes. These dyes can be delivered to the early embryo by means of microinjection into the adult gonad. Also, the localization of specific proteins can be followed using fluorescent protein tags. Examples are presented here demonstrating the use of a fluorescent lysosomal dye as well as fluorescently tagged histone and ubiquitin proteins. The labeled histone is used to visualize the DNA and thus identify the stage of the cell cycle. GFP-tagged ubiquitin reveals the dynamics of ubiquitinated vesicles in the early embryo. Observations of labeled lysosomes and GFP:: ubiquitin can be used to determine if there is colocalization between ubiquitinated vesicles and lysosomes. A technique for the microinjection of the lysosomal dye is presented. Techniques for generating transgenenic strains are presented elsewhere (1, 2). For imaging, embryos are cut out of adult hermaphrodite nematodes and mounted onto 2% agarose pads followed by time-lapse microscopy on a standard laser scanning confocal microscope or a spinning disk confocal microscope. This methodology provides for the high resolution visualization of early embryogenesis. PMID:21897352

  14. Opioid and Progesterone Signaling is Obligatory for Early Human Embryogenesis

    PubMed Central

    Gallego, Miguel J.; Porayette, Prashob; Kaltcheva, Maria M.; Meethal, Sivan Vadakkadath

    2009-01-01

    The growth factors that drive the division and differentiation of stem cells during early human embryogenesis are unknown. The secretion of endorphins, progesterone (P4), human chorionic gonadotropin, 17?-estradiol, and gonadotropin-releasing hormone by trophoblasts that lie adjacent to the embryoblast in the blastocyst suggests that these pregnancy-associated factors may directly signal the growth and development of the embryoblast. To test this hypothesis, we treated embryoblast-derived human embryonic stem cells (hESCs) with ICI 174,864, a ?-opioid receptor antagonist, and RU-486 (mifepristone), a P4 receptor competitive antagonist. Both antagonists potently inhibited the differentiation of hESC into embryoid bodies, an in vitro structure akin to the blastocyst containing all three germ layers. Furthermore, these agents prevented the differentiation of hESC aggregates into columnar neuroectodermal cells and their organization into neural tube-like rosettes as determined morphologically. Immunoblot analyses confirmed the obligatory role of these hormones; both antagonists inhibited nestin expression, an early marker of neural precursor cells normally detected during rosette formation. Conversely, addition of P4 to hESC aggregates induced nestin expression and the formation of neuroectodermal rosettes. These results demonstrate that trophoblast-associated hormones induce blastulation and neurulation during early human embryogenesis. PMID:18803462

  15. Cell morphodynamics visualization from images of zebrafish embryogenesis.

    PubMed

    Campana, Matteo; Sarti, Alessandro

    2010-07-01

    Laser scanning microscopy provides high-resolution nondestructive in vivo imaging to capture specific structures that have been fluorescently labeled, such as cellular nuclei and membranes, throughout early zebrafish embryogenesis. An increasingly challenging problem biologists must face is how to effectively explore, follow, and study the thousands of cells contained in the resulting time-varying volume data that are large in space, time, and variable domain. Visual data explorations, such as direct volume rendering, have been successfully used for the analysis of volumetric data. However, visualizing large-scale time-varying fields remains a challenging problem. In this paper we present a novel Focus+Context animated volume rendering. The technique is based on the distance map of objects of interest and on a scene graph architecture. We demonstrate that distance map driven volume rendering, implemented in modern graphics hardware, is suited to generate run time and interactive representations such as ghosted rendering and cut-away rendering. The experimental results on zebrafish embryogenesis data demonstrate that the technique is suited to uncover and to analyze biological events, such as organogenesis, contained in time-varying volumetric dataset. PMID:20171844

  16. Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula.

    PubMed

    Kurdyukov, Sergey; Song, Youhong; Tiew, Terence W-Y; Wang, Xin-Ding; Nolan, Kim E; Rose, Ray J

    2015-01-01

    Early embryogenesis starting from a single cell zygote goes through rapid cell division and morphogenesis, and is morphologically characterized by pre-globular, globular, heart, torpedo and cotyledon stages. This progressive development is under the tight regulation of a complex molecular network. Harvesting sufficient early embryos at a similar stage of development is essential for investigating the cellular and molecular regulation of early embryogenesis. This is not straightforward since early embryogenesis undergoes rapid morphogenesis in a short while e.g. 8 days for Medicago truncatula to reach the early cotyledon stage. Here, we address the issue by two approaches. The first one establishes a linkage between embryo development and pod morphology in helping indicate the stage of the zygotic embryo. This is particularly based on the number of pod spirals and development of the spines. An alternative way to complement the in vivo studies is via culturing leaf explants to produce somatic embryos. The medium includes an unusual hormone combination - an auxin (1-naphthaleneacetic acid), a cytokinin (6-benzylaminopurine), abscisic acid and gibberellic acid. The different stages can be discerned growing out of the callus without dissection. PMID:26131626

  17. Somatic retrotransposition in the cancer genome

    E-print Network

    Helman, Elena

    2014-01-01

    Cancer is a complex disease of the genome exhibiting myriad somatic mutations, from single nucleotide changes to various chromosomal rearrangements. The technological advances of next-generation sequencing enable high-throughput ...

  18. (Somatic mutations in nuclear and mitochondrial DNA)

    SciTech Connect

    Not Available

    1992-01-01

    The study is concerned the design of new assays that may detect rare somatic mutations in nuclear and mitochondrial DNA, which may increase upon exposure to mutagens, and thus become a marker of human exposure to such mutagens. Two assays for somatic mutation were presented, one for mitochondrial DNA deletions which was developed by the author, and one for deletions of the ADA gene which resides in the nucleus.

  19. The role of catastrophizing in somatic illness

    E-print Network

    Wilson, Michelle Denise

    1990-01-01

    all groups on all measures TABLE 3: Means of measures by group 29 30 INTRODUCTION The Role of Catastrophizing in Somatic Illness That stress has a role in the etiology and mai. ntenance of pain and somatic distress is widely accepted. Interest... the experience of pain and to reduce perception of pain or distress (Turk 8 Rudy, 1986). Catastrophizing may be a component of a general coping style or a narrowly focused strategy used only with specific stressors or in certain situations (Wickramasekera...

  20. Plant regeneration in vitro from embryogenic cultures of spring- and winter-type barley ( Hordeum vulgare L.) varieties

    Microsoft Academic Search

    R. Liihrs; H. Lörz

    1987-01-01

    Immature embryos of 41 lines of barley were screened in vitro for callus induction and somatic embryogenesis on different media to establish totipotent cultures. The use of modified MS and CC media, both supplemented with 1 g\\/l casein hydrolysate, and the substitution of agarose for agar resulted in the highest frequencies of somatic embryo induction. Embryogenic callus was induced and

  1. The expression and roles of parent-of-origin genes in early embryogenesis of angiosperms

    PubMed Central

    Luo, An; Shi, Ce; Zhang, Liyao; Sun, Meng-Xiang

    2014-01-01

    Uniparental transcripts during embryogenesis may arise due to gamete delivery during fertilization or genomic imprinting. Such transcripts have been found in a number of plant species and appear critical for the early development of embryo or endosperm in seeds. Although the regulatory expression mechanism and function of these genes in embryogenesis require further elucidation, recent studies suggest stage-specific and highly dynamic features that might be essential for critical developmental events such as zygotic division and cell fate determination during embryogenesis. Here, we summarize the current work in this field and discuss future research directions. PMID:25566300

  2. Current insights into hormonal regulation of microspore embryogenesis

    PubMed Central

    ?ur, Iwona; Dubas, Ewa; Krzewska, Monika; Janowiak, Franciszek

    2015-01-01

    Plant growth regulator (PGR) crosstalk and interaction with the plant’s genotype and environmental factors play a crucial role in microspore embryogenesis (ME), controlling microspore-derived embryo differentiation and development as well as haploid/doubled haploid plant regeneration. The complexity of the PGR network which could exist at the level of biosynthesis, distribution, gene expression or signaling pathways, renders the creation of an integrated model of ME-control crosstalk impossible at present. However, the analysis of the published data together with the results received recently with the use of modern analytical techniques brings new insights into hormonal regulation of this process. This review presents a short historical overview of the most important milestones in the recognition of hormonal requirements for effective ME in the most important crop plant species and complements it with new concepts that evolved over the last decade of ME studies. PMID:26113852

  3. TOPLESS mediates auxin-dependent transcriptional repression during Arabidopsis embryogenesis.

    PubMed

    Szemenyei, Heidi; Hannon, Mike; Long, Jeff A

    2008-03-01

    The transcriptional response to auxin is critical for root and vascular development during Arabidopsis embryogenesis. Auxin induces the degradation of AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors, freeing their binding partners, the AUXIN RESPONSE FACTOR (ARF) proteins, which can activate transcription of auxin response genes. We show that TOPLESS (TPL) can physically interact with IAA12/BODENLOS (IAA12/BDL) through an ETHYLENE RESPONSE FACTOR (ERF)-associated amphiphilic repression (EAR) motif. TPL can repress transcription in vivo and is required for IAA12/BDL repressive activity. In addition, tpl-1 can suppress the patterning defects of the bdl-1 mutant. Direct interaction between TPL and ARF5/MONOPTEROS, which is regulated by IAA12/BDL, results in a loss-of-function arf5/mp phenotype. These observations show that TPL is a transcriptional co-repressor and further our understanding of how auxin regulates transcription during plant development. PMID:18258861

  4. Dynamic Nucleosome Organization at hox Promoters during Zebrafish Embryogenesis

    PubMed Central

    Weicksel, Steven E.; Xu, Jia; Sagerström, Charles G.

    2013-01-01

    Nucleosome organization at promoter regions plays an important role in regulating gene activity. Genome-wide studies in yeast, flies, worms, mammalian embryonic stem cells and transformed cell lines have found well-positioned nucleosomes flanking a nucleosome depleted region (NDR) at transcription start sites. This nucleosome arrangement depends on DNA sequence (cis-elements) as well as DNA binding factors and ATP-dependent chromatin modifiers (trans-factors). However, little is understood about how the nascent embryonic genome positions nucleosomes during development. This is particularly intriguing since the embryonic genome must undergo a broad reprogramming event upon fusion of sperm and oocyte. Using four stages of early embryonic zebrafish development, we map nucleosome positions at the promoter region of 37 zebrafish hox genes. We find that nucleosome arrangement at the hox promoters is a progressive process that takes place over several stages. At stages immediately after fertilization, nucleosomes appear to be largely disordered at hox promoter regions. At stages after activation of the embryonic genome, nucleosomes are detectable at hox promoters, with positions becoming more uniform and more highly occupied. Since the genomic sequence is invariant during embryogenesis, this progressive change in nucleosome arrangement suggests that trans-factors play an important role in organizing nucleosomes during embryogenesis. Separating hox genes into expressed and non-expressed groups shows that expressed promoters have better positioned and occupied nucleosomes, as well as distinct NDRs, than non-expressed promoters. Finally, by blocking the retinoic acid-signaling pathway, we disrupt early hox gene transcription, but observe no effect on nucleosome positions, suggesting that active hox transcription is not a driving force behind the arrangement of nucleosomes at the promoters of hox genes during early development. PMID:23671670

  5. Somatic Mutations in Cerebral Cortical Malformations

    PubMed Central

    Jamuar, Saumya S.; Lam, Anh-Thu N.; Kircher, Martin; D'Gama, Alissa M.; Wang, Jian; Barry, Brenda J.; Zhang, Xiaochang; Hill, Robert Sean; Partlow, Jennifer N.; Rozzo, Aldo; Servattalab, Sarah; Mehta, Bhaven K.; Topcu, Meral; Amrom, Dina; Andermann, Eva; Dan, Bernard; Parrini, Elena; Guerrini, Renzo; Scheffer, Ingrid E.; Berkovic, Samuel F.; Leventer, Richard J.; Shen, Yiping; Wu, Bai Lin; Barkovich, A. James; Sahin, Mustafa; Chang, Bernard S.; Bamshad, Michael; Nickerson, Deborah A.; Shendure, Jay; Poduri, Annapurna; Yu, Timothy W.; Walsh, Christopher A.

    2014-01-01

    BACKGROUND Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated. METHODS Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, ?200×) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing. RESULTS Validated, causal mutations were found in 27 persons (17%; range, 10 to 30% for each phenotype). Mutations were somatic in 8 of the 27 (30%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria. CONCLUSIONS Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.) PMID:25140959

  6. Spatial Anisotropies and Temporal Fluctuations in Extracellular Matrix Network Texture during Early Embryogenesis

    E-print Network

    Loganathan, Rajprasad; Potetz, Brain R.; Rongish, Brenda J.; Little, Charles D.

    2012-05-31

    Early stages of vertebrate embryogenesis are characterized by a remarkable series of shape changes. The resulting morphological complexity is driven by molecular, cellular, and tissue-scale biophysical alterations. Operating at the cellular level...

  7. governed by fibroblast growth factor during embryogenesis. Nat. Neurosci. 2, 246253

    E-print Network

    Wang, Xiaoqin

    governed by fibroblast growth factor during embryogenesis. Nat. Neurosci. 2, 246­253 11 Raballo, R. In a modern society, we are constantly exposed to a noisy environment: for example, while driving a car during

  8. Induction voidmeter

    DOEpatents

    Anderson, Thomas T. (Downers Grove, IL); Roop, Conard J. (Lockport, IL); Schmidt, Kenneth J. (Midlothian, IL); Brewer, John (Oak Lawn, IL)

    1986-01-01

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  9. Induction voidmeter

    DOEpatents

    Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

    1983-12-21

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  10. Improved alliin yield in somatic embryos of Allium sativum L. (cv. Yamuna safed) as analyzed by HPTLC.

    PubMed

    Nasim, S A; Mujib, A; Rashmi, K; Samar, F; Junaid, A; Mahmooduzzafar

    2009-12-01

    Direct somatic embryo formation (without intervening callus) from garlic clove basal tissue was induced in which the influence of plant growth regulators (PGRs) on various explants was examined. Medium added with 2.0 mg/l 6-benzylaminopurine (BAP) and 0.5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) were the most effective PGR combination for somatic embryo induction. It induced embryos directly in 85.5% of the basal clove explant. Callus induction was also obtained from other parts of explant and 2.0 mg/l 2,4-D induced callusing in 86.5% of the inoculated explants. Protein, amino acid and alliin content were measured in callus and in embryos. Somatic embryos had more soluble protein and free amino acid compared to callus. HPTLC analysis revealed that alliin was significantly high in somatic embryos compared to undifferentiated callus tissue; the content was even more in older embryos. The present study of Allium indicates that the event of morphogenetic development including in vitro embryogeny can effectively be analysed by monitoring the changes of biochemical profiles. PMID:20015835

  11. Coherent Somatic Mutation in Autoimmune Disease

    PubMed Central

    Ross, Kenneth Andrew

    2014-01-01

    Background Many aspects of autoimmune disease are not well understood, including the specificities of autoimmune targets, and patterns of co-morbidity and cross-heritability across diseases. Prior work has provided evidence that somatic mutation caused by gene conversion and deletion at segmentally duplicated loci is relevant to several diseases. Simple tandem repeat (STR) sequence is highly mutable, both somatically and in the germ-line, and somatic STR mutations are observed under inflammation. Results Protein-coding genes spanning STRs having markers of mutability, including germ-line variability, high total length, repeat count and/or repeat similarity, are evaluated in the context of autoimmunity. For the initiation of autoimmune disease, antigens whose autoantibodies are the first observed in a disease, termed primary autoantigens, are informative. Three primary autoantigens, thyroid peroxidase (TPO), phogrin (PTPRN2) and filaggrin (FLG), include STRs that are among the eleven longest STRs spanned by protein-coding genes. This association of primary autoantigens with long STR sequence is highly significant (). Long STRs occur within twenty genes that are associated with sixteen common autoimmune diseases and atherosclerosis. The repeat within the TTC34 gene is an outlier in terms of length and a link with systemic lupus erythematosus is proposed. Conclusions The results support the hypothesis that many autoimmune diseases are triggered by immune responses to proteins whose DNA sequence mutates somatically in a coherent, consistent fashion. Other autoimmune diseases may be caused by coherent somatic mutations in immune cells. The coherent somatic mutation hypothesis has the potential to be a comprehensive explanation for the initiation of many autoimmune diseases. PMID:24988487

  12. Induction of pluripotency.

    PubMed

    Heffernan, Corey; Liu, Jun; Sumer, Huseyin; Malaver-Ortega, Luis F; Verma, Rajneesh; Carvalho, Edmund; Verma, Paul J

    2013-01-01

    The molecular and phenotypic irreversibility of mammalian cell differentiation was a fundamental principle of developmental biology at least until the 1980s, despite numerous reports dating back to the 1950s of the induction of pluripotency in amphibian cells by nuclear transfer (NT). Landmark reports in the 1980s and 1990s in sheep progressively challenged this dogmatic assumption; firstly, embryonic development of reconstructed embryos comprising whole (donor) blastomeres fused to enucleated oocytes, and famously, the cloning of Dolly from a terminally differentiated cell. Thus, the intrinsic ability of oocyte-derived factors to reverse the differentiated phenotype was confirmed. The concomitant elucidation of methods for human embryonic stem cell isolation and cultivation presented opportunities for therapeutic cell replacement strategies, particularly through NT of patient nuclei to enucleated oocytes for subsequent isolation of patient-specific (autologous), pluripotent cells from the resulting blastocysts. Associated logistical limitations of working with human oocytes, in addition to ethical and moral objections prompted exploration of alternative approaches to generate autologous stem cells for therapy, utilizing the full repertoire of factors characteristic of pluripotency, primarily through cell fusion and use of pluripotent cell extracts. Stunningly, in 2006, Japanese scientists described somatic cell reprogramming through delivery of four key factors (identified through a deductive approach from 24 candidate genes). Although less efficient than previous approaches, much of current stem cell research adopts this focused approach to cell reprogramming and (autologous) cell therapy. This chapter is a quasi-historical commentary of the various aforementioned approaches for the induction of pluripotency in lineage-committed cells, and introduces transcriptional and epigenetic changes occurring during reprogramming. PMID:23696349

  13. Somatic Cell Counts and Infection Rates for Cows of Varying Somatic Cell Count in Initial Test of First Lactation

    Microsoft Academic Search

    E. M. COFFEYfl; W. E. Vinson; R. E. Pearson

    1986-01-01

    Somatic cell counts (log, base 2)and rates of infection in first and subsequent lactations were examined by classes of somatic cell count in initial test day of first lactation to determine if cows with initially low\\

  14. Regulation of somatic firing dynamics by backpropagating dendritic spikes

    Microsoft Academic Search

    W. Hamish Mehaffey; Fernando R. Fernandez; Brent Doiron; Ray W. Turner

    2008-01-01

    Pyramidal cells of the apteronotid ELL have been shown to display a characteristic mechanism of burst discharge, which has been shown to play an important role in sensory coding. This form of bursting depends on a reciprocal dendro-somatic interaction, in which discharge of a somatic spike causes a dendritic spike, which in turn contributes a dendro-somatic current flow to create

  15. Checkpoint kinase 1 negatively regulates somatic hypermutation

    PubMed Central

    Frankenberger, Samantha; Davari, Kathrin; Fischer-Burkart, Sabine; Böttcher, Katrin; Tomi, Nils-Sebastian; Zimber-Strobl, Ursula; Jungnickel, Berit

    2014-01-01

    Immunoglobulin (Ig) diversification by somatic hypermutation in germinal center B cells is instrumental for maturation of the humoral immune response, but also bears the risk of excessive or aberrant genetic changes. Thus, introduction of DNA damage by activation-induced cytidine deaminase as well as DNA repair by multiple pathways need to be tightly regulated during the germinal center response to prevent lymphomagenesis. In the present study, we show that DNA damage checkpoint signaling via checkpoint kinase 1 (Chk1) negatively regulates somatic hypermutation. Chk1 inhibition in human B cell lymphoma lines as well as inactivation of Chk1 alleles by gene targeting in DT40 B cells leads to increased somatic hypermutation. This is apparently due to changes in DNA repair pathways regulated by Chk1, such as a decreased homologous recombination efficiency that also leads to decreased Ig gene conversion in DT40. Our data show that Chk1 signaling plays a crucial role in regulation of Ig diversification and sheds unexpected light on potential origins of aberrant somatic hypermutation in B cell lymphomagenesis. PMID:24423870

  16. Somatic Symptoms in Traumatized Children and Adolescents

    ERIC Educational Resources Information Center

    Kugler, Brittany B.; Bloom, Marlene; Kaercher, Lauren B.; Truax, Tatyana V.; Storch, Eric A.

    2012-01-01

    Childhood exposure to trauma has been associated with increased rates of somatic symptoms (SS), which may contribute to diminished daily functioning. One hundred and sixty-one children residing at a residential treatment home who had experienced neglect and/or abuse were administered the Trauma Symptom Checklist for Children (TSCC), the…

  17. Expression and cellular localization of Atrab28 during arabidopsis embryogenesis.

    PubMed

    Arenas-Mena, C; Raynal, M; Borrell, A; Varoquaux, F; Cutanda, M C; Stacy, R A; Pagès, M; Delseny, M; Culiáñez-Macià, F A

    1999-05-01

    The maize abscisic acid (ABA)-responsive gene rab28 has been shown to be ABA-inducible in embryos and vegetative tissues, expression being mostly restricted to vascular elements during late embryogenesis. In the course of an expressed sequence tags (ESTs) programme, we have isolated an Arabidopsis thaliana gene, Atrab28, encoding the orthologue of maize rab28. The Atrab28 cDNA is 1090 bp long, including a poly(A)+ stretch, and encodes a polypeptide of 262 amino acids. Atrab28 antibody against the recombinant protein recognizes a polipeptide of about 30 kDa and pI 6, in close agreement with the predicted molecular mass and pI. As for maize rab28, expression studies with Atrab28 revealed high specificity for embryo tissues, transcription being stimulated by the transcriptional activator abi3. In contrast, Atrab28 was not induced in vegetative tissues by ABA, osmotic stress or dehydration. The expression of Atrab28 mRNA and the accumulation of Atrab28 protein was largely restricted to provascular tissues of mature embryos and in the seed coat outer tegument and embryo and silique epidermis, as revealed by in situ hybridization and immunocytochemistry with anti-Atrab28 antibodies. PMID:10412913

  18. Charting Brachyury-mediated developmental pathways during early mouse embryogenesis.

    PubMed

    Lolas, Macarena; Valenzuela, Pablo D T; Tjian, Robert; Liu, Zhe

    2014-03-25

    To gain insights into coordinated lineage-specification and morphogenetic processes during early embryogenesis, here we report a systematic identification of transcriptional programs mediated by a key developmental regulator--Brachyury. High-resolution chromosomal localization mapping of Brachyury by ChIP sequencing and ChIP-exonuclease revealed distinct sequence signatures enriched in Brachyury-bound enhancers. A combination of genome-wide in vitro and in vivo perturbation analysis and cross-species evolutionary comparison unveiled a detailed Brachyury-dependent gene-regulatory network that directly links the function of Brachyury to diverse developmental pathways and cellular housekeeping programs. We also show that Brachyury functions primarily as a transcriptional activator genome-wide and that an unexpected gene-regulatory feedback loop consisting of Brachyury, Foxa2, and Sox17 directs proper stem-cell lineage commitment during streak formation. Target gene and mRNA-sequencing correlation analysis of the T(c) mouse model supports a crucial role of Brachyury in up-regulating multiple key hematopoietic and muscle-fate regulators. Our results thus chart a comprehensive map of the Brachyury-mediated gene-regulatory network and how it influences in vivo developmental homeostasis and coordination. PMID:24616493

  19. Development of an in vitro regeneration system for Theobroma cacao from mature tissues

    Microsoft Academic Search

    C. L Tan; D. B Furtek

    2003-01-01

    Induction of somatic embryogenesis from tissues in unopened flower buds of cocoa was studied with respect to physiological age, type of floral explant, genotype, and medium composition and phytohormones. Two-to-three-week-old staminodes were found to be the best explants for embryogenesis. Embryogenesis was affected by genotype and sugars. Two main types of abnormalities of the embryos were observed: fusion of the

  20. Chromatin dynamics in pollen mother cells underpin a common scenario at the somatic-to-reproductive fate transition of both the male and female lineages in Arabidopsis

    PubMed Central

    She, Wenjing; Baroux, Célia

    2015-01-01

    Unlike animals, where the germline is established early during embryogenesis, plants set aside their reproductive lineage late in development in dedicated floral organs. The specification of pollen mother cells (PMC) committed to meiosis takes place in the sporogenous tissue in anther locules and marks the somatic-to-reproductive cell fate transition toward the male reproductive lineage. Here we show that Arabidopsis PMC differentiation is accompanied by large-scale changes in chromatin organization. This is characterized by significant increase in nuclear volume, chromatin decondensation, reduction in heterochromatin, eviction of linker histones and the H2AZ histone variant. These structural alterations are accompanied by dramatic, quantitative changes in histone modifications levels compared to that of surrounding somatic cells that do not share a sporogenic fate. All these changes are highly reminiscent of those we have formerly described in female megaspore mother cells (MMC). This indicates that chromatin reprogramming is a common underlying scenario in the somatic-to-reproductive cell fate transition in both male and female lineages. PMID:25972887

  1. Effect of ovary induction on bread wheat anther culture: ovary genotype and developmental stage, and candidate gene association

    PubMed Central

    Castillo, Ana M.; Sánchez-Díaz, Rosa A.; Vallés, María P.

    2015-01-01

    Ovary pre-conditioned medium and ovary co-culture increased the efficiency of green doubled haploid plant production in bread wheat anther culture. The positive effect of this medium led to a 6- and 11-fold increase in the numbers of embryos and green plants, respectively, having a greater effect on a medium-low responding cultivar. Ovary genotype and developmental stage significantly affected microspore embryogenesis. By the use of Caramba ovaries it was possible to reach a 2-fold increase in the number of embryos and green plants, and to decrease the rate of albinism. Mature ovaries from flowers containing microspores at a late binucleate stage raised the number of embryos and green plants by 25–46% as compared to immature ovaries (excised from flowers with microspores at a mid-late uninucleate stage). The highest numbers of embryos and green plants were produced when using mature Caramba ovaries. Ovaries from Galeón, Tigre, and Kilopondio cultivars successfully induced microspore embryogenesis at the same rate as Caramba ovaries. Moreover, Tigre ovaries raised the percentage of spontaneous chromosome doubling up to 71%. Attempts were made to identify molecular mechanisms associated to the inductive effect of the ovaries on microspore embryogenesis. The genes TAA1b, FLA26, and WALI6 associated to wheat microspore embryogenesis, the CGL1 gene involved in glycan biosynthesis or degradation, and the FER gene involved in the ovary signaling process were expressed and/or induced at different rates during ovary culture. The expression pattern of FLA26 and FER could be related to the differences between genotypes and developmental stages in the inductive effect of the ovary. Our results open opportunities for new approaches to increase bread wheat doubled haploid production by anther culture, and to identify the functional components of the ovary inductive effect on microspore embryogenesis. PMID:26150821

  2. Unipolar Induction

    Microsoft Academic Search

    P. Hraskó

    2008-01-01

    The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and calculated in Sect. 1. Dielectrics are considered in Sect. 2, where the role of the electric moment due to moving magnetic dipole moment is clarified. Sect. 3

  3. Germ-granule components prevent somatic development in the C. elegans germline

    PubMed Central

    Knutson, Andrew Kek?pa'a; Egelhofer, Thea A.; Campbell, Anne C.; Strome, Susan

    2014-01-01

    Summary Specialized ribonucleoprotein organelles collectively known as germ granules are found in the germline cytoplasm from worms to humans [1]. In Drosophila, germ granules have been implicated in germline determination [2]. C. elegans germ granules, known as P granules, do not appear to be required for primordial germ cell (PGC) determination [3], but their components are still needed for fertility [4–6]. One potential role for P granules is to maintain germline fate and totipotency. This is suggested by the loss of P granules from germ cells that transform into somatic cell types, e.g. in germlines lacking MEX-3 and GLD-1 or upon neuronal induction by CHE-1 [7, 8]. However, it has not been established whether loss of P granules is the cause or effect of cell-fate transformation. To test cause-effect, we severely compromised P granules by simultaneously knocking down factors that nucleate granule formation (PGL-1 and PGL-3) and promote their perinuclear localization (GLH-1 and GLH-4) [9], and investigated if that causes germ cells to lose totipotency and initiate somatic reprogramming. We found that compromising P granules causes germ cells to express neuronal and muscle markers and send out neurite-like projections, suggesting that P granules maintain totipotency and germline identity by antagonizing somatic fate. PMID:24746798

  4. Evolution and the molecular basis of somatic hypermutation of antigen receptor genes.

    PubMed Central

    Diaz, M; Flajnik, M F; Klinman, N

    2001-01-01

    Somatic hypermutation of immunoglobulin genes occurs in many vertebrates including sharks, frogs, camels, humans and mice. Similarities among species reveal a common mechanism and these include the AGC/T sequence hot spot, preponderance of base substitutions, a bias towards transitions and strand bias. There are some differences among species, however, that may unveil layers of the mechanism. These include a G:C bias in frog and shark IgM but not in nurse shark antigen receptor (NAR), a high frequency of doublets in NAR hypermutation, and the co-occurrence of somatic hypermutation with gene conversion in some species. Here we argue that some of the similarities and differences among species are best explained by error-prone DNA synthesis by the translesion synthesis DNA polymerase zeta (Pol zeta) and, as suggested by others, induction of DNA synthesis by DNA breaks in antigen receptor variable genes. Finally, targeting of the variable genes is probably obtained via transcription-related elements, and it is the targeting phase of somatic hypermutation that is the most likely to reveal molecules unique to adaptive immunity. PMID:11205333

  5. LEAPdb: a database for the late embryogenesis abundant proteins

    PubMed Central

    2010-01-01

    Background Late Embryogenesis Abundant Proteins database (LEAPdb) contains resource regarding LEAP from plants and other organisms. Although LEAP are grouped into several families, there is no general consensus on their definition and on their classification. They are associated with abiotic stress tolerance, but their actual function at the molecular level is still enigmatic. The scarcity of 3-D structures for LEAP remains a handicap for their structure-function relationships analysis. Finally, the growing body of published data about LEAP represents a great amount of information that needs to be compiled, organized and classified. Results LEAPdb gathers data about 8 LEAP sub-families defined by the PFAM, the Conserved Domain and the InterPro databases. Among its functionalities, LEAPdb provides a browse interface for retrieving information on the whole database. A search interface using various criteria such as sophisticated text expression, amino acids motifs and other useful parameters allows the retrieving of refined subset of entries. LEAPdb also offers sequence similarity search. Information is displayed in re-ordering tables facilitating the analysis of data. LEAP sequences can be downloaded in three formats. Finally, the user can submit his sequence(s). LEAPdb has been conceived as a user-friendly web-based database with multiple functions to search and describe the different LEAP families. It will likely be helpful for computational analyses of their structure - function relationships. Conclusions LEAPdb contains 769 non-redundant and curated entries, from 196 organisms. All LEAP sequences are full-length. LEAPdb is publicly available at http://forge.info.univ-angers.fr/~gh/Leadb/index.php. PMID:20359361

  6. Trafficking of bdelloid rotifer late embryogenesis abundant proteins.

    PubMed

    Tripathi, Rashmi; Boschetti, Chiara; McGee, Brian; Tunnacliffe, Alan

    2012-08-15

    The bdelloid rotifer Adineta ricciae is an asexual microinvertebrate that can survive desiccation by entering an ametabolic state known as anhydrobiosis. Two late embryogenesis abundant (LEA) proteins, ArLEA1A and ArLEA1B, have been hypothesized to contribute to desiccation tolerance in these organisms, since in vitro assays suggest that ArLEA1A and ArLEA1B stabilize desiccation-sensitive proteins and membranes, respectively. To examine their functions in vivo, it is important to analyse the cellular distribution of the bdelloid LEA proteins. Bioinformatics predicted their translocation into the endoplasmic reticulum (ER) via an N-terminal ER translocation signal and persistence in the same compartment via a variant C-terminal retention signal sequence ATEL. We assessed the localization of LEA proteins in bdelloids and in a mammalian cell model. The function of the N-terminal sequence of ArLEA1A and ArLEA1B in mediating ER translocation was verified, but our data showed that, unlike classical ER-retention signals, ATEL allows progression from the ER to the Golgi and limited secretion of the proteins into the extracellular medium. These results suggest that the N-terminal ER translocation signal and C-terminal ATEL sequence act together to regulate the distribution of rotifer LEA proteins within intracellular vesicular compartments, as well as the extracellular space. We speculate that this mechanism allows a small number of LEA proteins to offer protection to a large number of desiccation-sensitive molecules and structures both inside and outside cells in the bdelloid rotifer. PMID:22837450

  7. Structural changes during early embryogenesis in wheat pollen

    Microsoft Academic Search

    F. J. Bonet; A. Olmedilla

    2000-01-01

    Summary We have made a detailed cytological examination of the development of wheat embryoids, monitoring their initial divisions from two to ten cells by both light and electron microscopy. According to our observations the first embryogenic division is symmetrical. After the androgenesis induction treatment, there is a decrease in ribosome population with cells that have inactive nucleoli made up almost

  8. Proliferation Rate of Somatic Cells Affects Reprogramming Efficiency*

    PubMed Central

    Xu, Yongyu; Wei, Xiaoyuan; Wang, Min; Zhang, Ru; Fu, Yanbin; Xing, Mingzhe; Hua, Qiuhong; Xie, Xin

    2013-01-01

    The discovery of induced pluripotent stem (iPS) cells provides not only new approaches for cell replacement therapy, but also new ways for drug screening. However, the undefined mechanism and relatively low efficiency of reprogramming have limited the application of iPS cells. In an attempt to further optimize the reprogramming condition, we unexpectedly observed that removing c-Myc from the Oct-4, Sox-2, Klf-4, and c-Myc (OSKM) combination greatly enhanced the generation of iPS cells. The iPS cells generated without c-Myc attained salient pluripotent characteristics and were capable of producing full-term mice through tetraploid complementation. We observed that forced expression of c-Myc induced the expression of many genes involved in cell cycle control and a hyperproliferation state of the mouse embryonic fibroblasts during the early stage of reprogramming. This enhanced proliferation of mouse embryonic fibroblasts correlated negatively to the overall reprogramming efficiency. By applying small molecule inhibitors of cell proliferation at the early stage of reprogramming, we were able to improve the efficiency of iPS cell generation mediated by OSKM. Our data demonstrated that the proliferation rate of the somatic cell plays critical roles in reprogramming. Slowing down the proliferation of the original cells might be beneficial to the induction of iPS cells. PMID:23439651

  9. Emerging patterns of somatic mutations in cancer

    PubMed Central

    Watson, Ian R.; Takahashi, Koichi; Futreal, P. Andrew; Chin, Lynda

    2014-01-01

    The advance in technological tools for massively parallel, high-throughput sequencing of DNA has enabled the comprehensive characterization of somatic mutations in large number of tumor samples. Here, we review recent cancer genomic studies that have assembled emerging views of the landscapes of somatic mutations through deep sequencing analyses of the coding exomes and whole genomes in various cancer types. We discuss the comparative genomics of different cancers, including mutation rates, spectrums, and roles of environmental insults that influence these processes. We highlight the developing statistical approaches used to identify significantly mutated genes, and discuss the emerging biological and clinical insights from such analyses as well as the challenges ahead translating these genomic data into clinical impacts. PMID:24022702

  10. Neuroendocrine regulation of somatic growth in fishes.

    PubMed

    Dai, XiangYan; Zhang, Wei; Zhuo, ZiJian; He, JiangYan; Yin, Zhan

    2015-02-01

    Growth is a polygenic trait that is under the influence of multiple physiological pathways regulating energy metabolism and muscle growth. Among the possible growth-regulating pathways in vertebrates, components of the somatotropic axis are thought to have the greatest influence. There is growing body of literature focusing on the somatotropic axis and its role regulating growth in fish. This includes research into growth hormone, upstream hypothalamic hormones, insulin-like growth factors, and downstream signaling molecules. Many of these signals have both somatic effects stimulating the growth of tissues and metabolic effects that play a role in nutrient metabolism. Signals of other endocrine axes exhibit profound effects on the function of the somatotropic axis in vivo. In this review we highlight recent advances in our understanding of the teleost fish endocrine somatotropic axis, including emerging research using genetic modified models. These studies have revealed new aspects and challenges associated with regulation of the important steps of somatic growth. PMID:25655896

  11. Factors affecting maturation of avocado somatic embryos

    Microsoft Academic Search

    a Centro de Investigación

    The effect of mineral salts, sucrose, gellan gum, abscisic acid and coconut water on maturation of avocado (Persea americanaMill.) somatic embryos was studied. Use of B5 major salts was essential to obtain white-opaque embryos. Sucrose at 175 mM, gellan gum (6.8 g l?1) or coconut water (10-20%) also enhanced the recovery of white-opaque embryos. Abscisic acid slightly enhanced the appearance

  12. Nuclear and Somatic Cell Genetic Reprogramming

    Microsoft Academic Search

    Maurizio Zuccotti; Silvia Garagna; Carlo Alberto Redi

    \\u000a Nuclear and somatic cell genetic reprogramming has seen a huge improvement during the past 10 years since the cloning of the\\u000a first mammal, Dolly the sheep. In this chapter we will summarise the advancement in nuclear and cell reprogramming by cell\\u000a fusion, using amphibian eggs or egg extracts, with cell extracts, with synthetic molecules, or by induced expression of specific

  13. [Reprogramming of somatic cells. Problems and solutions].

    PubMed

    Schneider, T A; Fishman, V S; Liskovykh, M A; Ponamartsev, S V; Serov, O L; Tomilin, A N; Alenina, N

    2014-01-01

    An adult mammal is composed of more than 200 different types of specialized somatic cells whose differentiated state remains stable over the life of the organism. For a long time it was believed that the differentiation process is irreversible, and the transition between the two types of specialized cells is impossible. The possibility of direct conversion of one differentiated cell type to another was first shown in the 80s of the last century in experiments on the conversion of fibroblasts into myoblasts by ectopic expression of the transcription factor MyoD. Surprisingly, this technology has remained unclaimed in cell biology for a long time. Interest in it revived after 200 thanks to the research of Novel Prize winner Shinya Yamanaka who has shown that a small set of transcription factors (Oct4, Sox2, Klf4 and c-Myc) is capable of restoring pluripotency in somatic cells which they lost in the process of differentiation. In 2010, using a similar strategy and the tissue-specific transcription factors Vierbuchen and coauthors showed the possibility of direct conversion of fibroblasts into neurons, i. e. the possibility of transdifferentiation of one type of somatic cells in the other. The works of these authoras were a breakthrough in the field of cell biology and gave a powerful impulse to the development of cell technologies for the needs of regenerative medicine. The present review discusses the main historical discoveries that preceded this work, evaluates the status of the problem and the progress in the development of methods for reprogramming at the moment, describes the main approaches to solving the problems of reprogramming of somatic cells into neuronal, and briefly discusses the prospect of application of reprogramming and transdifferentiation of cells for such important application areas as regenerative medicine, cell replacement therapy and drug screening. PMID:25929128

  14. Somatic Cell Nuclear Transfer in the Mouse

    NASA Astrophysics Data System (ADS)

    Kishigami, Satoshi; Wakayama, Teruhiko

    Somatic cell nuclear transfer (SCNT) has become a unique and powerful tool for epigenetic reprogramming research and gene manipulation in animals since “Dolly,” the first animal cloned from an adult cell was reported in 1997. Although the success rates of somatic cloning have been inefficient and the mechanism of reprogramming is still largely unknown, this technique has been proven to work in more than 10 mammalian species. Among them, the mouse provides the best model for both basic and applied research of somatic cloning because of its abounding genetic resources, rapid sexual maturity and propagation, minimal requirements for housing, etc. This chapter describes a basic protocol for mouse cloning using cumulus cells, the most popular cell type for NT, in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. In particular, we focus on a new, more efficient mouse cloning protocol using trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, which increases both in vitro and in vivo developmental rates from twofold to fivefold. This new method including TSA will be helpful to establish mouse cloning in many laboratories.

  15. Cloned mice derived from somatic cell nuclei.

    PubMed

    Hosaka, K; Ohi, S; Ando, A; Kobayashi, M; Sato, K

    2000-12-01

    In 1997, a cloned sheep "Dolly" was produced by nuclear transfer of somatic cell. The first birth of cloned mice derived from some somatic cells were succeeded in 1998. At present, it is shown that somatic cells, cumulus cells, fibroblasts and Sertoli cells can be used to the study of cloned animal as nuclear donor. In this study investigation was designed to compare with efficiency on the production of cloned embryos by using the microinjection and the electrofusion methods for nuclear transfer. Oocyte enucleation was performed with a micromanipulator. The oocyte was held by holding pipette, and was enucleated using a beveled pipette. Microinjection method: Cell's nucleus injection was carried out by piezo-micromanipulator. Cytochalasin B treated cumulus cell was aspirated into a injection pipette, and was broken its plasma membrane using the injection pipette. Then, the cumulus cell was injected into the enucleated ooplasm directly. Electrofusion method: The cell was aspirated into a beveled pipette, and then an aspirated cell was inserted into perivitelline space. Then, the pair of enucleated oocyte and cell was fused using electrical cell fusion apparatus. The reconstituted embryos were activated after nuclear transfer using St2+. Reconstituted embryos had been produced by the microinjection showed the embryonic development to over 8-cell stages. But, the rate of fragmentation of reconstituted embryos by the microinjection showed a little high rate in comparison with the electrofusion. When some reconstituted embryos by the microinjection were transplanted to pseudopregnant females' oviduct, 9 fetuses were observed at 14 days post coitum. PMID:11329940

  16. Predictive factors for somatization in a trauma sample

    PubMed Central

    2009-01-01

    Background Unexplained somatic symptoms are common among trauma survivors. The relationship between trauma and somatization appears to be mediated by posttraumatic stress disorder (PTSD). However, only few studies have focused on what other psychological risk factors may predispose a trauma victim towards developing somatoform symptoms. Methods The present paper examines the predictive value of PTSD severity, dissociation, negative affectivity, depression, anxiety, and feeling incompetent on somatization in a Danish sample of 169 adult men and women who were affected by a series of explosions in a firework factory settled in a residential area. Results Negative affectivity and feelings of incompetence significantly predicted somatization, explaining 42% of the variance. PTSD was significant until negative affectivity was controlled for. Conclusion Negative affectivity and feelings of incompetence significantly predicted somatization in the trauma sample whereas dissociation, depression, and anxiety were not associated with degree of somatization. PTSD as a risk factor was mediated by negative affectivity. PMID:19126224

  17. Release of somatic embryogenic potential from excised zygotic embryos of carrot and maintenance of proembryonic cultures in hormone-free medium

    NASA Technical Reports Server (NTRS)

    Smith, D. L.; Krikorian, A. D.

    1989-01-01

    Excised zygotic embryos, mericarps ("seeds") and hypocotyls of seedlings of cultivated carrot Daucus carota cv. Scarlet Nantes were evaluated for their ability to generate somatic embryos on a semisolid hormone-free nutrient medium. Neither intact zygotic embryos nor hypocotyls ever produced somatic embryos. However, mericarps and broken zygotic embryos were excellent sources for somatic embryo production (response levels as high as 86%). Somatic embryo formation was highest from cotyledons, but was also observed on isolated hypocotyls and root tips of mature zygotic embryos. On media containing unreduced nitrogen, somatic embryo formation led to the generation of vigorous cultures comprised entirely of somatic embryos at various stages of development which in turn proliferated still other somatic embryos. However, a medium was devised which when 1-5 mM NH4+ was the sole nitrogen source, led only to a proliferation of globular proembryos. Sustained subculturing of these proembryos at 2-3 week intervals enabled establishment of highly uniform cultures in which no further development into more mature stages of embryonic development occurred. These have been maintained, without decline, as morphogenetically competent proembryonic globules for over ten months. A basal medium containing from 1-5 mM NH4+ as the sole nitrogen source appears not to be inductive to somatic proembryo formation. Instead, such a medium is best thought of as permissive to the expression of embryogenically determined cells within zygotic embryos. By excising and breaking or wounding zygotic embryos, constituent cells are probably released from positional or chemical restraints and thus are able to express their innate embryogenic potential. Once a proembryonic culture is established, this medium containing 1-5 mM NH4+ as the sole nitrogen source provides a nonpermissive environment to the development and growth of later embryonic stages, but it does allow the continued formation and multiplication of globular somatic proembryos. The sequence of events leading from excised broken zygotic embryos to the formation of somatic embryos and the maintenance of somatic proembryos are demonstrated by scanning electron microscopy and histological preparations. Germination levels from intact zygotic embryos on media with varying levels and ratios of unreduced vs. reduced inorganic nitrogen were determined as well and provided baseline or control data on the type of response obtained from nonwounded material.

  18. Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells

    Microsoft Academic Search

    Junying Yu; Maxim A. Vodyanik; Kim Smuga-Otto; Jessica Antosiewicz-Bourget; Jennifer L. Frane; Shulan Tian; Jeff Nie; Gudrun A. Jonsdottir; Victor Ruotti; Ron Stewart; Igor I. Slukvin; James A. Thomson

    2007-01-01

    Somatic cell nuclear transfer allows trans-acting factors present in the mammalian oocyte to reprogram somatic cell nuclei to an undifferentiated state. We show that four factors (OCT4, SOX2, NANOG, and LIN28) are sufficient to reprogram human somatic cells to pluripotent stem cells that exhibit the essential characteristics of embryonic stem (ES) cells. These induced pluripotent human stem cells have normal

  19. Proteolysis in Milk Associated with Increasing Somatic Cell Counts

    Microsoft Academic Search

    G. F. Senyk; D. M. Barbano; W. F. Shipe

    1985-01-01

    Individual cow samples were collected and preserved with potassium dichromate. Somatic cells counts were determined. Tyrosine value was used as an index of pro- teolysis. Sixty-six samples ranged in somatic cell count from < 50,000 to > 2,000,000\\/ml. Initial milk tyrosine values and tyrosine values for milks incubated for 24 h at 37°C showed proteolytic activity increased with increasing somatic

  20. Human somatic mutation assays as biomarkers of carcinogenesis

    SciTech Connect

    Compton, P.J.E.; Smith, M.T. (Univ. of California, Berkeley (United States)); Hooper, K. (California Dept. of Health Services, Berkeley (United States))

    1991-08-01

    This paper describes four assays that detect somatic gene mutations in humans: the hypoxanthine-guanine phosphoribosyl transferase assay, the glycophorin A assay, the HLA-A assay, and the sickle cell hemoglobin assay. Somatic gene mutations can be considered a biomarker of carcinogenesis, and assays for somatic mutation may assist epidemiologists in studies that attempt to identify factors associated with increased risks of cancer. Practical aspects of the use of these assays are discussed.

  1. Advances in Reprogramming Somatic Cells to Induced Pluripotent Stem Cells

    Microsoft Academic Search

    Minal Patel; Shuying Yang

    2010-01-01

    Traditionally, nuclear reprogramming of cells has been performed by transferring somatic cell nuclei into oocytes, by combining\\u000a somatic and pluripotent cells together through cell fusion and through genetic integration of factors through somatic cell\\u000a chromatin. All of these techniques changes gene expression which further leads to a change in cell fate. Here we discuss recent\\u000a advances in generating induced pluripotent

  2. Shoot regeneration and embryogenesis in lily shoot tips cryopreserved by droplet vitrification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shoot regeneration and embryogenesis were, for the first time, achieved directly in shoot tips of Lilium Oriental hybrid ‘Siberia’ following cryopreservation by droplet-vitrification. Shoot tips (2 mm in length) including 2-3 leaf primordia were excised from 4-week-old adventitious shoots directly r...

  3. Wnt Signaling in Oncogenesis and Embryogenesis-a Look Outside the Nucleus

    Microsoft Academic Search

    Mark Peifer; Paul Polakis

    2000-01-01

    The Wnt cell-cell signaling pathway plays a critical and evolutionarily conserved role in directing cell fates during embryogenesis. In addition, inappropriate activation of the Wnt signal transduction pathway plays a role in a variety of human cancers. Many recent studies of Wnt signaling have provided mechanistic insight into these dual roles. Here we focus on two areas of rapid advance:

  4. LEA (Late Embryogenesis Abundant) proteins and their encoding genes in Arabidopsis thaliana

    Microsoft Academic Search

    Michaela Hundertmark; Dirk K Hincha

    2008-01-01

    BACKGROUND: LEA (late embryogenesis abundant) proteins have first been described about 25 years ago as accumulating late in plant seed development. They were later found in vegetative plant tissues following environmental stress and also in desiccation tolerant bacteria and invertebrates. Although they are widely assumed to play crucial roles in cellular dehydration tolerance, their physiological and biochemical functions are largely

  5. VERTEBRAL ABNORMALITIES IN JUVENILE INLAND SILVERSIDES, MENIDIA BERYLLINA, EXPOSED TO TERBUFOS DURING EMBRYOGENESIS

    EPA Science Inventory

    Embryos of the inland silverside, Menidia beryllina, were exposed to nominal concentration of 50 ug terbufos 1-1 during the first five days of embryogenesis. ilversides were maintained in clean dilute seawater until 37 days after hatching. adiographs revealed compressed and use v...

  6. Nucleic acid metabolism during seed embryogenesis. Comprehensive progress report, September 1973June 1976. [Cotton plants

    Microsoft Academic Search

    Dure

    1976-01-01

    Progress is reported on studies on the biochemistry of cotton seed embryogenesis and germination. Data are included on the processing of the stored mRNA of cotton cotyledons during early germination, the characterization of the cotton genome, and the development of the cotton chloroplast protein synthesizing system during germination. (CH)

  7. Neuro-Evolution Using Recombinational Algorithms and Embryogenesis for Robotic Control

    E-print Network

    Fernandez, Thomas

    Neuro-Evolution Using Recombinational Algorithms and Embryogenesis for Robotic Control Thesis individuals helped in the creation of the research presented here, and it would be near impossible to list has been built. #12;v Abstract Control tasks involving dramatic nonlinearities, such as decision

  8. Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to

    E-print Network

    Paris-Sud XI, Université de

    Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to Protect) seed mitochondria. PsLEAm revealed typical LEA features such as high hydrophilicity and repeated motifs. The overall results constitute, to our knowledge, the first characterization of a LEA protein in mitochondria

  9. Ancient origin of somatic and visceral neurons

    PubMed Central

    2013-01-01

    Background A key to understanding the evolution of the nervous system on a large phylogenetic scale is the identification of homologous neuronal types. Here, we focus this search on the sensory and motor neurons of bilaterians, exploiting their well-defined molecular signatures in vertebrates. Sensorimotor circuits in vertebrates are of two types: somatic (that sense the environment and respond by shaping bodily motions) and visceral (that sense the interior milieu and respond by regulating vital functions). These circuits differ by a small set of largely dedicated transcriptional determinants: Brn3 is expressed in many somatic sensory neurons, first and second order (among which mechanoreceptors are uniquely marked by the Brn3+/Islet1+/Drgx+ signature), somatic motoneurons uniquely co-express Lhx3/4 and Mnx1, while the vast majority of neurons, sensory and motor, involved in respiration, blood circulation or digestion are molecularly defined by their expression and dependence on the pan-visceral determinant Phox2b. Results We explore the status of the sensorimotor transcriptional code of vertebrates in mollusks, a lophotrochozoa clade that provides a rich repertoire of physiologically identified neurons. In the gastropods Lymnaea stagnalis and Aplysia californica, we show that homologues of Brn3, Drgx, Islet1, Mnx1, Lhx3/4 and Phox2b differentially mark neurons with mechanoreceptive, locomotory and cardiorespiratory functions. Moreover, in the cephalopod Sepia officinalis, we show that Phox2 marks the stellate ganglion (in line with the respiratory — that is, visceral— ancestral role of the mantle, its target organ), while the anterior pedal ganglion, which controls the prehensile and locomotory arms, expresses Mnx. Conclusions Despite considerable divergence in overall neural architecture, a molecular underpinning for the functional allocation of neurons to interactions with the environment or to homeostasis was inherited from the urbilaterian ancestor by contemporary protostomes and deuterostomes. PMID:23631531

  10. Mechanisms and models of somatic cell reprogramming

    PubMed Central

    Buganim, Yosef; Faddah, Dina A.; Jaenisch, Rudolf

    2014-01-01

    Conversion of somatic cells to pluripotency by defined factors is a long and complex process that yields embryonic stem cell-like cells that vary in their developmental potential. To improve the quality of resulting induced pluripotent stem cells (iPSCs), which is important for potential therapeutic applications, and to address fundamental questions about control of cell identity, molecular mechanisms of the reprogramming process must be understood. Here we discuss recent discoveries regarding the role of reprogramming factors in remodeling the genome, including new insights into the function of c-Myc, and describe the different phases, markers and emerging models of reprogramming. PMID:23681063

  11. In-depth proteomics characterization of embryogenesis of the honey bee worker (Apis mellifera ligustica).

    PubMed

    Fang, Yu; Feng, Mao; Han, Bin; Lu, Xiaoshan; Ramadan, Haitham; Li, Jianke

    2014-09-01

    Identifying proteome changes of honey bee embryogenesis is of prime importance for unraveling the molecular mechanisms that they underlie. However, many proteomic changes during the embryonic period are not well characterized. We analyzed the proteomic alterations over the complete time course of honey bee worker embryogenesis at 24, 48, and 72 h of age, using mass spectrometry-based proteomics, label-free quantitation, and bioinformatics. Of the 1460 proteins identified the embryo of all three ages, the core proteome (proteins shared by the embryos of all three ages, accounting for 40%) was mainly involved in protein synthesis, metabolic energy, development, and molecular transporter, which indicates their centrality in driving embryogenesis. However, embryos at different developmental stages have their own specific proteome and pathway signatures to coordinate and modulate developmental events. The young embryos (<24 h) stronger expression of proteins related to nutrition storage and nucleic acid metabolism may correlate with the cell proliferation occurring at this stage. The middle aged embryos (24-48 h) enhanced expression of proteins associated with cell cycle control, transporters, antioxidant activity, and the cytoskeleton suggest their roles to support rudimentary organogenesis. Among these proteins, the biological pathways of aminoacyl-tRNA biosynthesis, ?-alanine metabolism, and protein export are intensively activated in the embryos of middle age. The old embryos (48-72 h) elevated expression of proteins implicated in fatty acid metabolism and morphogenesis indicate their functionality for the formation and development of organs and dorsal closure, in which the biological pathways of fatty acid metabolism and RNA transport are highly activated. These findings add novel understanding to the molecular details of honey bee embryogenesis, in which the programmed activation of the proteome matches with the physiological transition observed during embryogenesis. The identified biological pathways and key node proteins allow for further functional analysis and genetic manipulation for both the honey bee embryos and other eusocial insects. PMID:24895377

  12. REVIEW OF INDUCTION LINACS

    E-print Network

    Faltens, A.

    2010-01-01

    accel­ erated with induction machines and steady pro­ gressof induction linacs, with several new machines becomingmachines have increased the opera­ tional experience level from the lkA level of the first generation of induction

  13. agronomie: plant genetics and breeding Regulation of somatic embryo development

    E-print Network

    Boyer, Edmond

    agronomie: plant genetics and breeding Regulation of somatic embryo development in Norway spruce; Somatic embryos can be used for vegetative propagation of genetically superior material. Additionally, that not all embryogenic cell lines contain embryos that can mature. We are using Norway spruce (Picea abies

  14. CHAPTER 1. GENE EXPRESSION PATTERNS DURING SOMATIC EMBRYO DEVELOPMENT AND

    E-print Network

    Carriquiry, Alicia

    1 CHAPTER 1. GENE EXPRESSION PATTERNS DURING SOMATIC EMBRYO DEVELOPMENT AND GERMINATION IN MAIZE Hi generated from embryogenic calli induced to undergo embryo maturation and germination. Over 1,000 genes in the 12,060 element arrays showed significant time variation during somatic embryo develop- ment

  15. Somatic (craniocervical) tinnitus and the dorsal cochlear nucleus hypothesis

    Microsoft Academic Search

    Robert Aaron Levine

    1999-01-01

    Purpose: Of all nonauditory sensory systems, only the somatosensory system seems to be related to tinnitus (eg, temporomandibular joint syndrome and whiplash). The purpose of this study is to describe the distinguishing characteristics of tinnitus associated with somatic events and to use these characteristics to develop a neurological model of somatic tinnitus.Materials and Methods: Case series.Results: Some patients with tinnitus,

  16. Birth of Beagle dogs by somatic cell nuclear transfer

    Microsoft Academic Search

    Mohammad Shamim Hossein; Yeon Woo Jeong; Sun Woo Park; Joung Joo Kim; Eugine Lee; Kyeong Hee Ko; Park Hyuk; Song Seung Hoon; Yeun Wook Kim; Sang Hwan Hyun; Taeyoung Shin; Woo Suk Hwang

    2009-01-01

    The present study was undertaken to evaluate two enucleation methods for somatic cell nuclear transfer (SCNT), and to standardize the optimum number of embryos for transfer to each recipient for canines. Oocytes retrieved from outbreed dogs were reconstructed with adult somatic cells from a male Beagle dog. A total of 134 or 267 oocytes were enucleated either by aspiration or

  17. Somatic Hypermutation of Immunoglobulin Genes Is Linked to Transcription Initiation

    Microsoft Academic Search

    Andrew Peters; Ursula Storb

    1996-01-01

    To identify DNA sequences that target the somatic hypermutation process, the immunoglobulin gene promoter located upstream of the variable (V) region was duplicated upstream of the constant (C) region of a ? transgene. Normally, ? genes are somatically mutated only in the VJ region, but not in the C region. In B cell hybridomas from mice with this ? transgene

  18. Epidemiologic Considerations in Reporting Herd Somatic Cell Counts

    Microsoft Academic Search

    W. D. Hueston; L. E. Heider

    1986-01-01

    The reporting of herd summaries of individual cow somatic cell counts differs between the nine Dairy Records Pro- cessing Centers. The objectives of this paper are 1) to review the present re- porting; 2) to compare the methods used to calculate herd somatic cell counts; and 3) to discuss the epidemio- logic implications of these methods. Estimates of central tendency

  19. Heritabilities of Measures of Somatic Cell Count per Lactation

    Microsoft Academic Search

    H. G. Monardes; B. W. Kennedy; J. E. Moxley

    1983-01-01

    Measures per lactation of somatic cell count were developed from monthly test- day observations for 3,966 Holstein cows on the official test option of the Quebec Dairy Herd Analysis Service. Cows were daughters of 99 sires that had five or more daughters in two or more herds. Two lactation periods were considered. One was based on all somatic cell counts

  20. The color image processing technology of the milk somatic cells

    Microsoft Academic Search

    Yuedong Wang; Heru Xue

    2010-01-01

    Image processing is widely applied in the field of the biology and medicine domain, however, the study of the milk somatic cell image processing technology is a new topic currently. This paper carries on the pre-processing to the milk somatic cell images firstly. Then in the foundation of the selection of the color space and the analysis based on the

  1. Reprogramming of Human Somatic Cells Using Human and Animal Oocytes

    Microsoft Academic Search

    Young Chung; Colin E. Bishop; Nathan R. Treff; Stephen J. Walker; Vladislav M. Sandler; Sandy Becker; Irina Klimanskaya; Wan-Song Wun; Randall Dunn; Rebecca M. Hall; Jing Su; Shi-Jiang Lu; Marc Maserati; Young-Ho Choi; Richard Scott; Anthony Atala; Ralph Dittman; Robert Lanza

    2009-01-01

    There is renewed interest in using animal oocytes to reprogram human somatic cells. Here we compare the re- programming of human somatic nuclei using oocytes obtained from animal and human sources. Comparative analysis of gene expression in morula-stage embryos was carried out using single-embryo transcriptome am- plification and global gene expression analyses. Genomic DNA fingerprinting and PCR analysis confirmed that

  2. Reprogramming of human somatic cells by bacteria.

    PubMed

    Ito, Naofumi; Ohta, Kunimasa

    2015-05-01

    In general, it had been believed that the cell fate restriction of terminally differentiated somatic cells was irreversible. In 1952, somatic cell nuclear transfer (SCNT) was introduced to study early embryonic development in frogs. So far, various mammalian species have been successfully cloned using the SCNT technique, though its efficiency is very low. Embryonic stem (ES) cells were the first pluripotent cells to be isolated from an embryo and have a powerful potential to differentiate into more than 260 types of cells. The generation of induced pluripotent stem (iPS) cells was a breakthrough in stem cell research, and the use of these iPS cells has solved problems such as low efficiency and cell fate restriction. These cells have since been used for clinical application, disease investigation, and drug selection. As it is widely accepted that the endosymbiosis of Archaea into eukaryotic ancestors resulted in the generation of eukaryotic cells, we examined whether bacterial infection could alter host cell fate. We previously showed that when human dermal fibroblast (HDF) cells were incorporated with lactic acid bacteria (LAB), the LAB-incorporated HDF cells formed clusters and expressed a subset of common pluripotent markers. Moreover, LAB-incorporated cell clusters could differentiate into cells derived from each of the three germinal layers both in vivo and in vitro, indicating successful reprogramming of host HDF cells by LAB. In the current review, we introduce the existing examples of cellular reprogramming by bacteria and discuss their nuclear reprogramming mechanisms. PMID:25866152

  3. Germline and somatic mutations in meningiomas.

    PubMed

    Smith, Miriam J

    2015-04-01

    Meningiomas arise from the arachnoid layer of the meninges that surround the brain and spine. They account for over one third of all primary central nervous system tumors in adults and confer a significant risk of location-dependent morbidity due to compression or displacement. A significant increase in risk of meningiomas is associated with neurofibromatosis type 2 (NF2) disease through mutation of the NF2 gene. In addition, approximately 5% of individuals with schwannomatosis disease develop meningiomas, through mutation of the SWI/SNF chromatin remodeling complex subunit, SMARCB1. Recently, a second SWI/SNF complex subunit, SMARCE1, was identified as a cause of clear cell meningiomas, indicating a wider role for this complex in meningioma disease. The sonic hedgehog (SHH)-GLI1 signaling pathway gene, SUFU, has also been identified as the cause of hereditary multiple meningiomas in a large Finnish family. The recent identification of somatic mutations in components of the SHH-GLI1 and AKT1-MTOR signaling pathways indicates the potential for cross talk of these pathways in the development of meningiomas. This review describes the known meningioma predisposition genes and their links to the recently identified somatic mutations. PMID:25857641

  4. Unipolar Induction

    E-print Network

    Hraskó, P

    2008-01-01

    The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and calculated in Sect. 1. Dielectrics are considered in Sect. 2, where the role of the electric moment due to moving magnetic dipole moment is clarified. Sect. 3 is devoted to the description of the effect in the corotating frame of reference. In Sect. 4 the theory is applied to the Earth core and it is shown that the calculated electric field falls precisely into the range of the ambient electric field observed in the Tethered Satellite System mission of NASA. In the last paragraph I reflect on whether flyby anomaly might be attributed to an electric effect.

  5. Unipolar Induction

    E-print Network

    P. Hraskó

    2010-11-07

    The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and calculated in Sect. 1. Dielectrics are considered in Sect. 2, where the role of the electric moment due to moving magnetic dipole moment is clarified. Sect. 3 is devoted to the description of the effect in the corotating frame of reference. In Sect. 4 the theory is applied to the Earth core and it is shown that the calculated electric field falls precisely into the range of the ambient electric field observed in the Tethered Satellite System mission of NASA. In the last paragraph I reflect on whether flyby anomaly might be attributed to an electric effect.

  6. Ion Induction Accelerators

    Microsoft Academic Search

    John J. Barnard; Kazuhiko Horioka

    2011-01-01

    \\u000a The description of beams in RF and induction accelerators share many common features. Likewise, there is considerable commonality\\u000a between electron induction accelerators (see Chap. 7) and ion induction accelerators. However, in contrast to electron induction\\u000a accelerators, there are fewer ion induction accelerators that have been operated as application-driven user facilities. Ion\\u000a induction accelerators are envisioned for applications (see Chap. 10)

  7. Somatic Point Mutation Calling in Low Cellularity Tumors

    PubMed Central

    Kassahn, Karin S.; Holmes, Oliver; Nones, Katia; Patch, Ann-Marie; Miller, David K.; Christ, Angelika N.; Harliwong, Ivon; Bruxner, Timothy J.; Xu, Qinying; Anderson, Matthew; Wood, Scott; Leonard, Conrad; Taylor, Darrin; Newell, Felicity; Song, Sarah; Idrisoglu, Senel; Nourse, Craig; Nourbakhsh, Ehsan; Manning, Suzanne; Wani, Shivangi; Steptoe, Anita; Pajic, Marina; Cowley, Mark J.; Pinese, Mark; Chang, David K.; Gill, Anthony J.; Johns, Amber L.; Wu, Jianmin; Wilson, Peter J.; Fink, Lynn; Biankin, Andrew V.; Waddell, Nicola; Grimmond, Sean M.; Pearson, John V.

    2013-01-01

    Somatic mutation calling from next-generation sequencing data remains a challenge due to the difficulties of distinguishing true somatic events from artifacts arising from PCR, sequencing errors or mis-mapping. Tumor cellularity or purity, sub-clonality and copy number changes also confound the identification of true somatic events against a background of germline variants. We have developed a heuristic strategy and software (http://www.qcmg.org/bioinformatics/qsnp/) for somatic mutation calling in samples with low tumor content and we show the superior sensitivity and precision of our approach using a previously sequenced cell line, a series of tumor/normal admixtures, and 3,253 putative somatic SNVs verified on an orthogonal platform. PMID:24250782

  8. Recent advancements in cloning by somatic cell nuclear transfer

    PubMed Central

    Ogura, Atsuo; Inoue, Kimiko; Wakayama, Teruhiko

    2013-01-01

    Somatic cell nuclear transfer (SCNT) cloning is the sole reproductive engineering technology that endows the somatic cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chromatin of the reconstructed embryos. Although it will take a considerable time before we fully understand the nature of genomic programming and totipotency, we may expect that somatic cell cloning technology will soon become broadly applicable to practical purposes, including medicine, pharmaceutical manufacturing and agriculture. Here we review recent progress in somatic cell cloning, with a special emphasis on epigenetic studies using the laboratory mouse as a model. PMID:23166393

  9. Stimulation of Activin A\\/Nodal signaling is insufficient to induce definitive endoderm formation of cord blood-derived unrestricted somatic stem cells

    Microsoft Academic Search

    Caitlin E Filby; Robert Williamson; Peter van Kooy; Alice Pébay; Mirella Dottori; Ngaire J Elwood; Faten Zaibak

    2011-01-01

    Introduction  Unrestricted somatic stem cells (USSC) derived from umbilical cord blood are an attractive alternative to human embryonic\\u000a stem cells (hESC) for cellular therapy. USSC are capable of forming cells representative of all three germ line layers. The\\u000a aim of this study was to determine the potential of USSC to form definitive endoderm following induction with Activin A, a\\u000a protein known

  10. Development of coffee somatic and zygotic embryos to plants differs in the morphological, histochemical and hydration aspects.

    PubMed

    Etienne, Hervé; Bertrand, Benoît; Georget, Frédéric; Lartaud, Marc; Montes, Fabienne; Dechamp, Eveline; Verdeil, Jean-Luc; Barry-Etienne, Dominique

    2013-06-01

    In Coffea arabica L., the development of direct sowing of somatic embryos (SE) in planting substrate, with subsequent nursery production of plants, has promoted the industrialization of somatic embryogenesis. However, plant conversion rates are still low and require improvements to enhance the cost-effectiveness of commercial micropropagation. With the aim of improving plant regeneration from SE, we studied the morphological and histological criteria and water characteristics during germination and plant conversion of zygotic embryos (ZE) and SE. At the cotyledonary stage, SE produced in a 1 l RITA(®) temporary immersion bioreactor (area 55.8 cm(2)) were morphologically similar in size (2-3 mm) but abnormal as compared with mature ZE. Protein and starch reserve levels were extremely low throughout germination and conversion to plantlets, while the water status remained steady [water content (WC) from 76 to 87%, ? from -0.37 to -0.47 MPa, pressure potential from 0.69 to 0.24 MPa]. In ZE, spectacular hydration occurred during the first 3 weeks (WC from 37 to 75%; ? from -6.24 to -1.0 MPa). Cotyledons remained undifferentiated for 10 weeks after sowing. Conversely, after only 3 weeks under germination conditions in a RITA(®) bioreactor, spongy and palisade parenchyma and stomata formed in SE cotyledons. The ZE plant conversion was faster than that of SE (14 vs. 22 weeks) and more efficient (rates 96 vs. 55%), with much more substantial hypocotyl and cotyledon development. The use of a new 5 l MATIS(®) bioreactor (area 355 cm(2)), designed especially to favor embryo dispersion and light transmittance to SE, markedly improved the embryo-to-plantlet conversion rate (91%). These results highlight the morphological heterogeneity and lack of protein reserves in SE at the beginning of the germination phase and marked differences in water characteristics. However, they also reveal high phenotypic plasticity, leading to a highly efficient plantlet conversion rate due to better embryo dispersion and light transmittance in more horizontal bioreactors. PMID:23729274

  11. An iTRAQ-based proteomics approach to clarify the molecular physiology of somatic embryo development in Prince Rupprecht's larch (Larix principis-rupprechtii Mayr).

    PubMed

    Zhao, Jian; Li, Hui; Fu, Shuangbin; Chen, Bo; Sun, Wenting; Zhang, Junqi; Zhang, Jinfeng

    2015-01-01

    Prince Rupprecht's larch (Larix principis-rupprechtii Mayr) is a native high-value forest tree species in North China whose clonal propagation through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. To date, research has focused on clarifying the molecular mechanism of SE, but proteomic studies are still in the early stages. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) analysis was performed on three developmental stages of SE in L. principis-rupprechtii in an attempt to identify a wide range of proteins that are regulated differentially during this process. Proteins were extracted and analyzed from the pro-embryogenic mass (PEM), globular embryo (GE), and cotyledon embryo (CE) stages of embryo development. We detected 503 proteins in total and identified 96 proteins expressed differentially during different developmental stages. The identified proteins were analyzed further to provide information about their expression patterns and functions during SE. Four clusters of proteins based on shared expression profiles were generated. Functional analysis showed that proteins involved in primary metabolism, phosphorylation, and oxidation reduction were upregulated during somatic embryo development. This work provides novel insights into the process of larch embryo development in vitro and a basis for further study of the biological process and opportunities for practical application of this knowledge. PMID:25781987

  12. Genotype by environment interaction for somatic cell score across bulk milk somatic cell count and days in milk

    Microsoft Academic Search

    M. P. L. Calus; L. L. G. Janss; R. F. Veerkamp

    2006-01-01

    The objective of this paper was to investigate the importance of a genotype x environment interaction (G x E) for somatic cell score (SCS) across levels of bulk milk somatic cell count (BMSCC), number of days in milk (DIM), and their interaction. Variance components were estimated with a model including random regressions for each sire on herd test-day BMSCC, DIM,

  13. A Digital Framework to Build, Visualize and Analyze a Gene Expression Atlas with Cellular Resolution in Zebrafish Early Embryogenesis

    E-print Network

    Luengo-Oroz, Miguel A.

    A gene expression atlas is an essential resource to quantify and understand the multiscale processes of embryogenesis in time and space. The automated reconstruction of a prototypic 4D atlas for vertebrate early embryos, ...

  14. Somatic cell mutagenicity in Drosophila melanogaster in comparison with genetic damage in early germ-cell stages.

    PubMed

    Vogel, E W; Zijlstra, J A

    1987-10-01

    With the intention of assessing the general performance, sensitivity and the underlying mechanisms of somatic cell mutagenicity assays in Drosophila, a study was undertaken to compare the effectiveness of 5 procarcinogens and 4 direct-acting agents in the white/white-coral eye mosaic assay (SMART) with their activity in early (premeiotic) male and female germ-cell stages, after exposure of Drosophila larvae. The outcome indicated a lack of agreement in the results from recessive lethal assays (SLRL) in comparison with the somatic mutation and recombination test (SMART). The procarcinogens 2-naphthylamine (NA), 3-methylcholanthrene (MC), 9,10-dimethylanthracene (DA) and 7,12-dimethylbenz[a]anthracene (DMBA), and the direct-acting mutagens bleomycin (BM), methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS), were quite efficient in producing somatic recombination and mutations in white/white-coral larvae, as opposed to only weak effects in early germ-cell stages. 2-Acetylaminofluorene (2AAF) showed marginal effects in both germ cells and somatic tissue after exposure of female larvae, but was inactive in testis. The discrepancy in mutational response between somatic cells and premeiotic germ cells is most impressive for MMS and BM. There is sufficient evidence for attributing a good sized proportion of the encountered variation to efficient error-free DNA repair of premutational damage and to segregational elimination during meiosis of deleterious mutations: (1) The efficient point mutagen ENU was the but one agent producing high levels of viable genetic alterations in early germ cells and in somatic cells. A similar behaviour was previously described for diethylnitrosamine, which ethylates DNA in the same fashion as ENU. (2) In early germ-cell stages of mei-9L1 male larvae, MMS induced multiple mutations (putative clusters) at a low dose differing by a factor 20-40 from those needed to produce an equivalent response in repair-competent strains. This is consistent with the concept of an active excision repair in premeiotic cells. (3) In the case of EMS, next to DNA repair, germinal selection seems to restrict the realization of EMS-induced genetic damage in premeiotic cells. (4) Bleomycin-induced chromosome aberrations caused high mortality rates in males (hemizygous for an X-chromosome) but not in females. MMS and BM, agents known to show preference for chromosome aberration induction, produced 3-6-fold higher rates of somatic mutational events (SME) in female genotypes as compared with the other sex.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3116419

  15. A somatic T15091C mutation in the Cytb gene of mouse mitochondrial DNA dominantly induces respiration defects.

    PubMed

    Hayashi, Chisato; Takibuchi, Gaku; Shimizu, Akinori; Mito, Takayuki; Ishikawa, Kaori; Nakada, Kazuto; Hayashi, Jun-Ichi

    2015-08-01

    Our previous studies provided evidence that mammalian mitochondrial DNA (mtDNA) mutations that cause mitochondrial respiration defects behave in a recessive manner, because the induction of respiration defects could be prevented with the help of a small proportion (10%-20%) of mtDNA without the mutations. However, subsequent studies found the induction of respiration defects by the accelerated accumulation of a small proportion of mtDNA with various somatic mutations, indicating the presence of mtDNA mutations that behave in a dominant manner. Here, to provide the evidence for the presence of dominant mutations in mtDNA, we used mouse lung carcinoma P29 cells and examined whether some mtDNA molecules possess somatic mutations that dominantly induce respiration defects. Cloning and sequence analysis of 40-48 mtDNA molecules from P29 cells was carried out to screen for somatic mutations in protein-coding genes, because mutations in these genes could dominantly regulate respiration defects by formation of abnormal polypeptides. We found 108 missense mutations existing in one or more of 40-48 mtDNA molecules. Of these missense mutations, a T15091C mutation in the Cytb gene was expected to be pathogenic due to the presence of its orthologous mutation in mtDNA from a patient with cardiomyopathy. After isolation of many subclones from parental P29 cells, we obtained subclones with various proportions of T15091C mtDNA, and showed that the respiration defects were induced in a subclone with only 49% T15091C mtDNA. Because the induction of respiration defects could not be prevented with the help of the remaining 51% mtDNA without the T15091C mutation, the results indicate that the T15091C mutation in mtDNA dominantly induced the respiration defects. PMID:26072375

  16. Domain landscapes of somatic mutations in cancer

    PubMed Central

    2012-01-01

    Background Large-scale tumor sequencing projects are now underway to identify genetic mutations that drive tumor initiation and development. Most studies take a gene-based approach to identifying driver mutations, highlighting genes mutated in a large percentage of tumor samples as those likely to contain driver mutations. However, this gene-based approach usually does not consider the position of the mutation within the gene or the functional context the position of the mutation provides. Here we introduce a novel method for mapping mutations to distinct protein domains, not just individual genes, in which they occur, thus providing the functional context for how the mutation contributes to disease. Furthermore, aggregating mutations from all genes containing a specific protein domain enables the identification of mutations that are rare at the gene level, but that occur frequently within the specified domain. These highly mutated domains potentially reveal disruptions of protein function necessary for cancer development. Results We mapped somatic mutations from the protein coding regions of 100 colon adenocarcinoma tumor samples to the genes and protein domains in which they occurred, and constructed topographical maps to depict the “mutational landscapes” of gene and domain mutation frequencies. We found significant mutation frequency in a number of genes previously known to be somatically mutated in colon cancer patients including APC, TP53 and KRAS. In addition, we found significant mutation frequency within specific domains located in these genes, as well as within other domains contained in genes having low mutation frequencies. These domain “peaks” were enriched with functions important to cancer development including kinase activity, DNA binding and repair, and signal transduction. Conclusions Using our method to create the domain landscapes of mutations in colon cancer, we were able to identify somatic mutations with high potential to drive cancer development. Interestingly, the majority of the genes involved have a low mutation frequency. Therefore, themethod shows good potential for identifying rare driver mutations in current, large-scale tumor sequencing projects. In addition, mapping mutations to specific domains provides the necessary functional context for understanding how the mutations contribute to the disease, and may reveal novel or more refined gene and domain target regions for drug development. PMID:22759657

  17. [Functional somatic syndrome in dental practice].

    PubMed

    Inamitsu, Tetsuaki

    2009-09-01

    Functional somatic syndromes (FSSs) are common in dental as well as medical practice. Many patients with unexplained symptoms in oro-maxillo-facial areas visit dentists, but they are not diagnosed and treated properly. Temporomandibular disorder, atypical facial pain, and glossodynia (burning mouth syndrome) are included in dental FSSs. These diseases overlap with each other and with FSSs in other organs, such as myofacial pain syndrome, tension-type headache, fibromyalgia, and chronic fatigue syndrome. They coexist with mental disorders, such as anxiety disorder, mood disorder, and somatoform disorder. Multidisciplinary and holistic approaches should be applied to dental FSSs; pharmacological therapy (antidepressants), physical therapy, and cognitive-behavioral therapy. Clinicians have to support a patient in"enjoying his/her life with symptoms". Dental specialists in "oral medicine" with psychosomatic viewpoints are now required. PMID:19768911

  18. The Somatic Genomic Landscape of Glioblastoma

    PubMed Central

    Brennan, Cameron W.; Verhaak, Roel G.W.; McKenna, Aaron; Campos, Benito; Noushmehr, Houtan; Salama, Sofie R.; Zheng, Siyuan; Chakravarty, Debyani; Sanborn, J. Zachary; Berman, Samuel H.; Beroukhim, Rameen; Bernard, Brady; Wu, Chang-Jiun; Genovese, Giannicola; Shmulevich, Ilya; Barnholtz-Sloan, Jill; Zou, Lihua; Vegesna, Rahulsimham; Shukla, Sachet A.; Ciriello, Giovanni; Yung, WK; Zhang, Wei; Sougnez, Carrie; Mikkelsen, Tom; Aldape, Kenneth; Bigner, Darell D.; Van Meir, Erwin G.; Prados, Michael; Sloan, Andrew; Black, Keith L.; Eschbacher, Jennifer; Finocchiaro, Gaetano; Friedman, William; Andrews, David W.; Guha, Abhijit; Iacocca, Mary; O’Neill, Brian P.; Foltz, Greg; Myers, Jerome; Weisenberger, Daniel J.; Penny, Robert; Kucherlapati, Raju; Perou, Charles M.; Hayes, D. Neil; Gibbs, Richard; Marra, Marco; Mills, Gordon B.; Lander, Eric; Spellman, Paul; Wilson, Richard; Sander, Chris; Weinstein, John; Meyerson, Matthew; Gabriel, Stacey; Laird, Peter W.; Haussler, David; Getz, Gad; Chin, Lynda

    2013-01-01

    We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer. PMID:24120142

  19. Depression in cultural context: "Chinese somatization," revisited.

    PubMed

    Ryder, Andrew G; Chentsova-Dutton, Yulia E

    2012-03-01

    We have presented a view of culture and mental health that builds on work in cultural psychiatry, anthropology, and cultural psychology, and applied it to research on culture and depression. In particular, we have returned to the well-known topic of Chinese somatization. A culture–mind–brain approach to these questions helps us think about them in a way that points toward new research. We have applied this approach to thinking about a single set of questions, relevant to a single (DSM-based) diagnosis, in a single cultural group. The potential, however, is to rethink how we conceptualize mental health in ways consistent with cultural psychiatry’s general perspective over the past several decades, while incorporating rather than rejecting the many recent advances in brain and behavior sciences. In so doing, we gain a more expanded and nuanced view of the global landscape of mental health, accompanied by a more expanded and nuanced view of individual patients. PMID:22370488

  20. The Epigenetics of Adult (Somatic) Stem Cells

    PubMed Central

    Eilertsen, Kenneth J.; Floyd, Z. Elizabeth; Gimble, Jeffrey M.

    2009-01-01

    While genetic studies have provided a wealth of information about health and disease, there is a growing awareness that individual characteristics are also determined by factors other than genetic sequences. These “epigenetic” changes broadly encompass the influence of the environment on gene regulation and expression and in a more narrow sense, describe the mechanisms controlling DNA methylation, histone modification and genetic imprinting. In this review, we focus on the epigenetic mechanisms that regulate adult (somatic) stem cell differentiation, beginning with the metabolic pathways and factors regulating chromatin structure and DNA methylation and the molecular biological tools that are currently available to study these processes. The role of these epigenetic mechanisms in manipulating adult stem cells is followed by a discussion of the challenges and opportunities facing this emerging field. PMID:18540823

  1. Somatic symptoms in traumatized children and adolescents.

    PubMed

    Kugler, Brittany B; Bloom, Marlene; Kaercher, Lauren B; Truax, Tatyana V; Storch, Eric A

    2012-10-01

    Childhood exposure to trauma has been associated with increased rates of somatic symptoms (SS), which may contribute to diminished daily functioning. One hundred and sixty-one children residing at a residential treatment home who had experienced neglect and/or abuse were administered the Trauma Symptom Checklist for Children (TSCC), the Multidimensional Anxiety Scale for Children, and the Children's Depression Inventory (CDI). Primary caregivers completed the Child Behavior Checklist. Two composite measures of SS were formed to represent both child- and caregiver-rated SS. Over 95% of children endorsed at least one SS on the child-rated measure. Children who had experienced sexual abuse had higher rates of SS relative to children who had not. Child-rated SS were highly correlated with the CDI total score and the TSCC subscales of anxiety, depression, posttraumatic stress, dissociation, and anger. The TSCC anxiety subscale mediated the relationship between sexual abuse and child-rated SS. PMID:22395849

  2. The Snail Family Gene Snai3 Is Not Essential for Embryogenesis in Mice

    PubMed Central

    Han, Xianghua; Booth, Carmen J.; Yoon, Jeong Kyo; Krebs, Luke T.; Gridley, Thomas

    2013-01-01

    The Snail gene family encodes zinc finger-containing transcriptional repressor proteins. Three members of the Snail gene family have been described in mammals, encoded by the Snai1, Snai2, and Snai3 genes. The function of the Snai1 and Snai2 genes have been studied extensively during both vertebrate embryogenesis and tumor progression and metastasis, and play critically important roles during these processes. However, little is known about the function of the Snai3 gene and protein. We describe here generation and analysis of Snai3 conditional and null mutant mice. We also generated an EYFP-tagged Snai3 null allele that accurately reflects endogenous Snai3 gene expression, with the highest levels of expression detected in thymus and skeletal muscle. Snai3 null mutant homozygous mice are viable and fertile, and exhibit no obvious phenotypic defects. These results demonstrate that Snai3 gene function is not essential for embryogenesis in mice. PMID:23762348

  3. Cells segmentation from 3-D confocal images of early zebrafish embryogenesis.

    PubMed

    Zanella, Cecilia; Campana, Matteo; Rizzi, Barbara; Melani, Camilo; Sanguinetti, Gonzalo; Bourgine, Paul; Mikula, Karol; Peyrieras, Nadine; Sarti, Alessandro

    2010-03-01

    We designed a strategy for extracting the shapes of cell membranes and nuclei from time lapse confocal images taken throughout early zebrafish embryogenesis using a partial-differential-equation-based segmentation. This segmentation step is a prerequisite for an accurate quantitative analysis of cell morphodynamics during embryogenesis and it is the basis for an integrated understanding of biological processes. The segmentation of embryonic cells requires live zebrafish embryos fluorescently labeled to highlight sub-cellular structures and designing specific algorithms by adapting classical methods to image features. Our strategy includes the following steps: the signal-to-noise ratio is first improved by an edge-preserving filtering, then the cell shape is reconstructed applying a fully automated algorithm based on a generalized version of the Subjective Surfaces technique. Finally we present a procedure for the algorithm validation either from the accuracy and the robustness perspective. PMID:19955038

  4. A highly efficient regeneration system via somatic embryogenesis from immature embryos of Egyptian wheat cultivars (Triticum aestivum L.) using different growth regulators

    Microsoft Academic Search

    Ashraf H. Fahmy; Yehia H. El-Shafy; Osama M. El-Shih; M. A. Madkour

    2004-01-01

    Two wheat cultivars (Giza 163 and Giza 164) were used to study the effect of three different growth regulators i.e. Thidiazuron (TDZ), Zeatin riboside (ZR) and Dicamba on regeneration efficiency. In comparing results of regeneration efficiency for the three growth regulators across the two cultivars, it is concluded that the highest regeneration efficiency was observed by using the highest TDZ

  5. Dynamic Hsp83 RNA localization during Drosophila oogenesis and embryogenesis.

    PubMed Central

    Ding, D; Parkhurst, S M; Halsell, S R; Lipshitz, H D

    1993-01-01

    Hsp83 is the Drosophila homolog of the mammalian Hsp90 family of regulatory molecular chaperones. We show that maternally synthesized Hsp83 transcripts are localized to the posterior pole of the early Drosophila embryo by a novel mechanism involving a combination of generalized RNA degradation and local protection at the posterior. This protection of Hsp83 RNA occurs in wild-type embryos and embryos produced by females carrying the maternal effect mutations nanos and pumilio, which eliminate components of the posterior polar plasm without disrupting polar granule integrity. In contrast, Hsp83 RNA is not protected at the posterior pole of embryos produced by females carrying maternal mutations that disrupt the posterior polar plasm and the polar granules--cappuccino, oskar, spire, staufen, tudor, valois, and vasa. Mislocalization of oskar RNA to the anterior pole, which has been shown to result in induction of germ cells at the anterior, leads to anterior protection of maternal Hsp83 RNA. These results suggest that Hsp83 RNA is a component of the posterior polar plasm that might be associated with polar granules. In addition, we show that zygotic expression of Hsp83 commences in the anterior third of the embryo at the syncytial blastoderm stage and is regulated by the anterior morphogen, bicoid. We consider the possible developmental significance of this complex control of Hsp83 transcript distribution. Images PMID:7684502

  6. Gametogenesis, embryogenesis, and larval features of the oviparous sponge Petrosia ficiformis (Haplosclerida, Demospongiae)

    Microsoft Academic Search

    Manuel Maldonado; Ana Riesgo

    2009-01-01

    This study describes the reproductive cycle of Petrosia ficiformis and documents for the first time embryogenesis in an oviparous haplosclerid demosponge. Gonochoric adults, occurring in 2:1\\u000a female\\/male ratios, spawned in late autumn, after a 7-month long oogenesis and a 2.5-week-long spermatogenesis. Following\\u000a a remarkable migration, the oocytes were released as 250 ?m eggs bearing attached polar bodies and a thin mucous

  7. Enhancement of embryogenesis and plant regeneration from barley anther culture by low doses of gamma irradiation

    Microsoft Academic Search

    M. I. E. Arabi; B. Al-Safadi; M. Jawhar; N. Mir-Ali

    2005-01-01

    Summary  The effects of 0,5 and 10 Gy doses of gamma irradiation on the enhancement of embryogenesis and plant regeneration efficiency\\u000a of three barley (Hordeum vulgare L.) genotypes, Igri, Arabi Abiad and AECS 76, were evaluated. Embryo yields at 5 and 10 Gy doses were significantly higher\\u000a than those of the control (OGy). This effect was genotype-dependent. The most responsive genotype

  8. Croup 3 Late Embryogenesis Abundant Proteins in Desiccation-Tolerant Seedlings of Wheat (Triticum aestivum 1.)

    Microsoft Academic Search

    M. K. Walker-Simmons

    Dormant seeds and young seedlings of wheat (Triticum aestivum L.) tolerate desiccation. A transcript expressed in this desiccation- tolerant tissue has been cloned and sequenced (I. Curry, C.F. Morris, M.K. Walker-Simmons (1991) Plant Mo1 Biol 16: 1073- 1076). This wheat cDNA clone encodes a protein that is homolo- gous to other group 3 late embryogenesis abundant (LEA) proteins. In this

  9. Evidence for Active Maintenance of Phylotranscriptomic Hourglass Patterns in Animal and Plant Embryogenesis

    PubMed Central

    Drost, Hajk-Georg; Gabel, Alexander; Grosse, Ivo; Quint, Marcel

    2015-01-01

    The developmental hourglass model has been used to describe the morphological transitions of related species throughout embryogenesis. Recently, quantifiable approaches combining transcriptomic and evolutionary information provided novel evidence for the presence of a phylotranscriptomic hourglass pattern across kingdoms. As its biological function is unknown it remains speculative whether this pattern is functional or merely represents a nonfunctional evolutionary relic. The latter would seriously hamper future experimental approaches designed to test hypotheses regarding its function. Here, we address this question by generating transcriptome divergence index (TDI) profiles across embryogenesis of Danio rerio, Drosophila melanogaster, and Arabidopsis thaliana. To enable meaningful evaluation of the resulting patterns, we develop a statistical test that specifically assesses potential hourglass patterns. Based on this objective measure we find that two of these profiles follow a statistically significant hourglass pattern with the most conserved transcriptomes in the phylotypic periods. As the TDI considers only recent evolutionary signals, this indicates that the phylotranscriptomic hourglass pattern is not a rudiment but possibly actively maintained, implicating the existence of some linked biological function associated with embryogenesis in extant species. PMID:25631928

  10. [Morphogenetic movement of cells in embryogenesis of Drosophila melanogaster: mechanism and genetic control].

    PubMed

    Simonova, O B; Burdina, N V

    2009-01-01

    Morphogenetic movement of cells is of significant importance in embryogenesis. It is necessary to identify the final position and configuration of the embryoTs tissues and share the positional information in differentiation. The healing of tissular injuries happens in the adult organism due to the cell layers' movement, and the directed macrophages migration to the nidus of infection assists the neutralization of inflammatory processes. Owing to the good level of knowledge, the fruit fly D. melanogaster is a perfect model object for the study of morphogenetic events in embryogenesis in connection with the cells movement. The description of Drosophila embryogenesis, mechanisms of ventral furrow formation, elongation of the germ band, and its contraction accompanied by dorsal closure was given. During these processes the movement of epithelial cells and the entire epithelial strata happens. The information about the genetic regulation of morphogenetic movement of D. melanogaster taking into consideration the scale of evolutionary conservatism of the cascades of the main signal, which control these processes in vertebrates, is presented. PMID:19894610

  11. Nuclear lamins and peripheral nuclear antigens during fertilization and embryogenesis in mice and sea urchins

    NASA Technical Reports Server (NTRS)

    Schatten, G.; Schatten, H.; Simerly, C.; Maul, G. G.; Chaly, N.

    1985-01-01

    Nuclear structural changes during fertilization and embryogenesis in mice and sea urchins are traced using four antibodies. The oocytes from virgin female mice, morulae and blastocytes from mated females, and gametes from the sea urchin Lytechnius variegatis are studied using mouse monoclonal antibodies to nuclear lamin A/C, monoclonal antibody to P1, human autoimmune antibodies to lamin A/C, and to lamin B. The mouse fertilization data reveal no lamins on the oocyte; however, lamins are present on the pronuclei, and chromosomes are found on the oocytes and pronuclei. It is detected that on the sea urchin sperm the lamins are reduced to acrosomal and centriolar fossae and peripheral antigens are around the sperm nucleus. The mouse sperm bind lamin antibodies regionally and do not contain antigens. Lamins and antigens are observed on both pronuclei and chromosomes during sea urchin fertilization. Mouse embryogenesis reveals that lamin A/C is not recognized at morula and blastocyst stages; however, lamin B stains are retained. In sea urchin embryogenesis lamin recognition is lost at the blastrula, gastrula, and plutei stages. It is noted that nuclear lamins lost during spermatogenesis are restored at fertilization and peripheral antigens are associated with the surface of chromosomes during meiosis and mitosis and with the periphery of the pronuclei and nuclei during interphase.

  12. Role of Filia, a maternal effect gene, in maintaining euploidy during cleavage-stage mouse embryogenesis.

    PubMed

    Zheng, Ping; Dean, Jurrien

    2009-05-01

    During oogenesis, mammalian eggs accumulate proteins required for early embryogenesis. Although limited data suggest a vital role of these maternal factors in chromatin reprogramming and embryonic genome activation, the full range of their functions in preimplantation development remains largely unknown. Here we report a role for maternal proteins in maintaining chromosome stability and euploidy in early-cleavage mouse embryogenesis. Filia, expressed in growing oocytes, encodes a protein that binds to MATER and participates in a subcortical maternal complex essential for cleavage-stage embryogenesis. The depletion of maternal stores of Filia impairs preimplantation embryo development with a high incidence of aneuploidy that results from abnormal spindle assembly, chromosome misalignment, and spindle assembly checkpoint (SAC) inactivation. In helping to ensure normal spindle morphogenesis, Filia regulates the proper allocation of the key spindle assembly regulators (i.e., AURKA, PLK1, and gamma-tubulin) to the microtubule-organizing center via the RhoA signaling pathway. Concurrently, Filia is required for the placement of MAD2, an essential component of the SAC, to kinetochores to enable SAC function. Thus, Filia is central to integrating the spatiotemporal localization of regulators that helps ensure euploidy and high-quality cell cycle progression in preimplantation mouse development. Defects in the well-conserved human homologue could play a similar role and account for recurrent human fetal wastage. PMID:19376971

  13. Developmental biochemistry of cottonseed embryogenesis and germination. XIII. Regulation of biosynthesis of principal storage proteins

    SciTech Connect

    Dure, L. III; Galau, G.A.

    1981-07-01

    The synthesis of the principal cottonseed storage proteins during embryogenesis was followed by analyses of protein synthesized in vivo and from purified RNA in vitro in the wheat germ system. The kinetics of in vivo labeling as well as immunochemical cross-reactivity indicate that the 52- and 48-kilodalton mature storage protein sets are derived from 70- and 67-kilodalton precursor protein sets that are abundant proteins in embryonic cotyledons and disappear in late embryogenesis. Identification of the initial translation products of the storage protein mRNA has not been clearly established although products of apparent molecular weights of 69,000 and 60,000 are the likely storage protein precursors. Storage protein synthesis falls off markedly in late embryogenesis simultaneously with the loss of a superabundant class of mRNAs that are presumed to be those for the storage proteins. The synthesis of these proteins ceases abruptly when immature embryos are removed from the boll and allowed to germinate precociously or when this precocious germination is prevented by incubation in abscisic acid. Thus, abscisic acid is not implicated in the expression of the storage protein genes. A scheme involving co-translational processing into vesicles, glycosylation, and slow in situ cleavage to produce the mature storage proteins is proposed.

  14. The Chromatin Targeting Protein Brd2 is Required for Neural Tube Closure and Embryogenesis

    PubMed Central

    Gyuris, Aron; Donovan, Diana J.; Seymour, Kimberly A.; Lovasco, Lindsay A.; Smilowitz, Nathaniel R.; Halperin, Anthony L. P.; Klysik, Jan E.; Freiman, Richard N.

    2009-01-01

    Chromatin modifications are essential for directing transcription during embryonic development. Bromodomain-containing protein 2 (Brd2; also called RING3 and Fsrg1) is one of four BET (bromodomain and extra terminal domain) family members known to selectively bind acetylated histones H3 and H4. Brd2 associates with multiple subunits of the transcriptional apparatus including the mediator, TFIID and Swi/Snf multi-protein complexes. While molecular interactions of Brd2 are known, the functions of Brd2 in mammalian embryogenesis remain unknown. In developing a mouse model deficient in Brd2, we find that Brd2 is required for the completion of embryogenesis and proper neural tube closure during development. Embryos lacking Brd2 expression survive up to embryonic day 13.5, soon after mid-gestation, and display fully penetrant neurulation defects that largely result in exencephaly of the developing hindbrain. In this study, we find that highest expression of Brd2 is detected in the developing neural tube, correlating with the neural tube defects found in Brd2-null embryos. Additionally, embryos lacking Brd2 expression display altered gene expression programs, including the mis-expression of multiple genes known to guide neuronal development. Together these results implicate essential roles for Brd2 as a critical integrator of chromatin structure and transcription during mammalian embryogenesis and neurogenesis. PMID:19362612

  15. Interactions between alpha-tocopherol, polyunsaturated fatty acids, and lipoxygenases during embryogenesis

    PubMed Central

    Lebold, Katie M; Traber, Maret G

    2013-01-01

    ?-Tocopherol is a lipid-soluble antioxidant that is specifically required for reproduction and embryogenesis. However, since its discovery, ?-tocopherol’s specific biologic functions, other than as an antioxidant, and the mechanism(s) mediating its requirement for embryogenesis, remain unknown. As an antioxidant, ?-tocopherol protects polyunsaturated fatty acids (PUFAs) from lipid peroxidation. ?-Tocopherol is likely required during embryonic development to protect PUFAs that are crucial to development, specifically arachidonic (ARA) and docosahexaenoic (DHA) acids. Additionally, ARA and DHA are metabolized to bioactive lipid mediators via lipoxygenase enzymes and ?-tocopherol may directly protect, or it may mediate the production and/or actions of these lipid mediators. In this review, we discuss how ?-tocopherol 1) prevents the nonspecific, radical-mediated peroxidation of PUFAs, 2) functions within a greater antioxidant network to modulate the production and/or function of lipid mediators derived from 12- and 12/15-lipoxygenase and 3) modulates 5-lipoxygenase activity. The application and implication of such interactions with be discussed in the context ?-tocopherol requirements during embryogenesis. PMID:23920314

  16. Molecular and cytogenetic constitution of plants obtained via two different somatic hybridization methods

    Microsoft Academic Search

    P. C. Binsfeld; H. Schnabl

    2002-01-01

    Somatic hybrids between Helianthus annuus and H. maximiliani obtained through two different hybridization methods were investigated. Random amplified polymorphic DNA markers of symmetric somatic hybrids (SSH) showed typical profiles of full somatic hybrid plants, while in asymmetric somatic hybrids (ASH) a small amount of alien genome was identified. Flow cytometric analysis of the genome size showed a strong correlation (r=0.92)

  17. Reprogramming of somatic cells induced by fusion of embryonic stem cells using hemagglutinating virus of Japan envelope (HVJ-E)

    SciTech Connect

    Yue, Xiao-shan [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan) [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Fujishiro, Masako [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)] [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Toyoda, Masashi [Department of Reproductive Biology, National Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535 (Japan)] [Department of Reproductive Biology, National Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan)] [Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Ito, Yoshihiro, E-mail: y-ito@riken.jp [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan) [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan)

    2010-04-16

    In this research, hemagglutinating virus of Japan envelope (HVJ-E) was used to reprogram somatic cells by fusion with mouse embryonic stem (ES) cells. Neomycin-resistant mouse embryonic fibroblasts (MEFs) were used as somatic cells. Nanog-overexpressing puromycin-resistant EB3 cells were used as mouse ES cells. These two cells were fused by exposing to HVJ-E and the generated fusion cells were selected by puromycin and G418 to get the stable fusion cell line. The fusion cells form colonies in feeder-free culture system. Microsatellite analysis of the fusion cells showed that they possessed genes from both ES cells and fibroblasts. The fusion cells were tetraploid, had alkali phosphatase activity, and expressed stem cell marker genes such as Pou5f1, Nanog, and Sox2, but not the fibroblast cell marker genes such as Col1a1 and Col1a2. The pluripotency of fusion cells was confirmed by their expression of marker genes for all the three germ layers after differentiation induction, and by their ability to form teratoma which contained all the three primary layers. Our results show that HVJ-E can be used as a fusion reagent for reprogramming of somatic cells.

  18. Reprogramming human somatic cells to pluripotency using RNA

    E-print Network

    Angel, Matthew (Matthew M.)

    2012-01-01

    Somatic cells can be reprogrammed to a pluripotent stem-cell state by ectopic expression of defined proteins. However, existing reprogramming methods take several weeks, suffer from low efficiencies, and most use DNA-based ...

  19. The place of asymmetric somatic hybridization in wheat breeding.

    PubMed

    Liu, Shuwei; Xia, Guangmin

    2014-04-01

    Since its first development some 40 years ago, the application of the somatic hybridization technique has generated a body of hybrid plant material involving a wide combination of parental species. Until the late 1990s, the technique was ineffective in wheat, as regeneration from protoplasts was proving difficult to achieve. Since this time, however, a successful somatic hybridization protocol for wheat has been established and used to generate a substantial number of both symmetric and asymmetric somatic hybrids and derived materials, especially involving the parental combination bread wheat and tall wheatgrass (Thinopyrum ponticum). This review describes the current state of the art for somatic hybridization in wheat and focuses on its potential application for wheat improvement. PMID:24370665

  20. Children with Psychological Distress or Epilepsy: Somatization and Adaptive Skills

    E-print Network

    Villarreal, Nichole

    2012-10-19

    with chronic illness (n = 94) to understand the relationship between adaptive skills and somatic complaints with the added medical factors of duration of illness and age of onset. The results of the children experiencing psychological distress suggest...

  1. Somatic mosaicism for oncogenic NRAS mutations in juvenile myelomonocytic leukemia.

    PubMed

    Doisaki, Sayoko; Muramatsu, Hideki; Shimada, Akira; Takahashi, Yoshiyuki; Mori-Ezaki, Makiko; Sato, Masanori; Kawaguchi, Hiroyuki; Kinoshita, Akitoshi; Sotomatsu, Manabu; Hayashi, Yasuhide; Furukawa-Hibi, Yoko; Yamada, Kiyofumi; Hoshino, Hideaki; Kiyoi, Hitoshi; Yoshida, Nao; Sakaguchi, Hirotoshi; Narita, Atsushi; Wang, Xinan; Ismael, Olfat; Xu, Yinyan; Nishio, Nobuhiro; Tanaka, Makito; Hama, Asahito; Koike, Kenichi; Kojima, Seiji

    2012-08-16

    Juvenile myelomonocytic leukemia (JMML) is a rare pediatric myeloid neoplasm characterized by excessive proliferation of myelomonocytic cells. Somatic mutations in genes involved in GM-CSF signal transduction, such as NRAS, KRAS, PTPN11, NF1, and CBL, have been identified in more than 70% of children with JMML. In the present study, we report 2 patients with somatic mosaicism for oncogenic NRAS mutations (G12D and G12S) associated with the development of JMML. The mutated allele frequencies quantified by pyrosequencing were various and ranged from 3%-50% in BM and other somatic cells (ie, buccal smear cells, hair bulbs, or nails). Both patients experienced spontaneous improvement of clinical symptoms and leukocytosis due to JMML without hematopoietic stem cell transplantation. These patients are the first reported to have somatic mosaicism for oncogenic NRAS mutations. The clinical course of these patients suggests that NRAS mosaicism may be associated with a mild disease phenotype in JMML. PMID:22753870

  2. Vision of the body increases interference on the somatic signal detection task

    Microsoft Academic Search

    Laura Mirams; Ellen Poliakoff; Richard J. Brown; Donna M. Lloyd

    2010-01-01

    Research suggests that attention has a significant effect on somatic perception in both healthy people and those who suffer\\u000a from somatic disturbance. The current study investigates the effects of attending to the body on somatic awareness and a particular\\u000a type of somatic disturbance: erroneous reports of touch sensation, as measured by the Somatic Signal Detection Task (SSDT).\\u000a During the SSDT,

  3. Somatic hypermutation and B-cell lymphoma.

    PubMed Central

    Dunn-Walters, D; Thiede, C; Alpen, B; Spencer, J

    2001-01-01

    During the B-cell response to T-cell-dependent antigens, the B cells undergo a rapid proliferative phase in the germinal centre. This is accompanied by the introduction of mutations into the immunoglobulin (Ig) variable region (V) genes. The B cells are then selected according to the affinity of the encoded immunoglobulin for antigen, resulting in affinity maturation of the response. Analysis of mutations in IgV genes has given insight into the history of individual B cells and their malignancies. In most cases, analysis of mutations confirms classifications of B-cell lineage designated by studies of cellular morphology and surface antigen expression. However, of particular interest is the subdivision of groups of malignancies by analysis of somatic hypermutation. It is now apparent that there are two subsets of chronic lymphocytic leukaemia (CLL), one with a low load of mutations and poor prognosis. and one with a heavy load of mutations with a much more favourable prognosis. In addition, in Burkitt's lymphoma, sporadic and endemic subtypes are now considered possibly to have a different pathogenesis, reflected in differences in the numbers of mutations. Hodgkin's disease, which was a mystery for many years, has now been shown to be a B-cell tumour. Although in many cases the Ig genes are crippled by somatic hypermutation, it is thought that failure to express Ig is more likely to be associated with problems of transcription. It has been proposed that the distribution of mutations in a B-cell lymphoma can be used to determine whether a lymphoma is selected. We have investigated the load and distribution of mutations in one group of lymphomas--marginal zone B-cell lymphomas of mucosa-associated lymphoid tissues (MALT-type lymphoma), which are dependent on Helicobacter pylori for disease progression, to investigate the limits of information that can be derived from such studies. Comparison of the load of mutations demonstrates that these tumours have approximately the same load of mutations as normal mucosal marginal zone B cells from the Peyer's patches and mucosal plasma cells. This is consistent with the origin of these cells from mucosal marginal zone B cells with plasma cell differentiation. To investigate selection in MALT lymphomas we compared a region of the framework region three in ten MALT lymphomas which use the V(H4) family, with the same codons in groups of V(H4) genes that are out of frame between V and J. The latter accumulate mutations but are not used and are not selected. A group of V(H4) genes are in-frame between V and J were also included for comparison. There were no obvious differences in the distribution of mutations between the groups of genes; the same hot spots and cold spots were apparent in each. In the MALT lymphomas, selection was apparent in the framework regions only and the tendency was to conserve. We therefore feel that there is selection to conserve antibody structure and that this does not reflect selection for antigen. We do not believe that antigen selection can be deduced reliably from sequence information alone. It is possible that somatic hypermutation could be a cause of malignancy since it has been shown that the process may generate DNA strand breaks and is known to be able to generate insertions and deletions. Such events may mediate the translocation of genes--a process that is pivotal in the evolution of many lymphomas. PMID:11205334

  4. Auxin Biosynthesis, Accumulation, Action and Transport are Involved in Stress-Induced Microspore Embryogenesis Initiation and Progression in Brassica napus.

    PubMed

    Rodríguez-Sanz, Héctor; Solís, María-Teresa; López, María-Fernanda; Gómez-Cadenas, Aurelio; Risueño, María C; Testillano, Pilar S

    2015-07-01

    Isolated microspores are reprogrammed in vitro by stress, becoming totipotent cells and producing embryos and plants via a process known as microspore embryogenesis. Despite the abundance of data on auxin involvement in plant development and embryogenesis, no data are available regarding the dynamics of auxin concentration, cellular localization and the expression of biosynthesis genes during microspore embryogenesis. This work involved the analysis of auxin concentration and cellular accumulation; expression of TAA1 and NIT2 encoding enzymes of two auxin biosynthetic pathways; expression of the PIN1-like efflux carrier; and the effects of inhibition of auxin transport and action by N-1-naphthylphthalamic acid (NPA) and ?-(p-chlorophenoxy) isobutyric acid (PCIB) during Brassica napus microspore embryogenesis. The results indicated de novo auxin synthesis after stress-induced microspore reprogramming and embryogenesis initiation, accompanying the first cell divisions. The progressive increase of auxin concentration during progression of embryogenesis correlated with the expression patterns of TAA1 and NIT2 genes of auxin biosynthetic pathways. Auxin was evenly distributed in early embryos, whereas in heart/torpedo embryos auxin was accumulated in apical and basal embryo regions. Auxin efflux carrier PIN1-like gene expression was induced in early multicellular embryos and increased at the globular/torpedo embryo stages. Inhibition of polar auxin transport (PAT) and action, by NPA and PCIB, impaired embryo development, indicating that PAT and auxin action are required for microspore embryo progression. NPA also modified auxin embryo accumulation patterns. These findings indicate that endogenous auxin biosynthesis, action and polar transport are required in stress-induced microspore reprogramming, embryogenesis initiation and progression. PMID:25907568

  5. [Somatic mutations in nuclear and mitochondrial DNA]. Progress report

    SciTech Connect

    Not Available

    1992-09-01

    The study is concerned the design of new assays that may detect rare somatic mutations in nuclear and mitochondrial DNA, which may increase upon exposure to mutagens, and thus become a marker of human exposure to such mutagens. Two assays for somatic mutation were presented, one for mitochondrial DNA deletions which was developed by the author, and one for deletions of the ADA gene which resides in the nucleus.

  6. Intergeneric symmetric and asymmetric somatic hybridization in Festuca and Lolium

    Microsoft Academic Search

    G. Spangenberg; Z. Y. Wang; G. Legris; P. Montavon; T. Takamizo; R. Pérez-Vicente; M. P. Vallés; J. Nagel; I. Potrykus

    1995-01-01

    Summary  Intergeneric symmetric and asymmetric somatic hybrids have been obtained by fusion of metabolically inactivated protoplasts\\u000a from embryogenic suspension cultures of tall fescue (Festuca arundinacea Schreb.) and unirradiated or 10–500 Gy-irradiated protoplasts from non-morphogenic cell suspensions of Italian ryegrass (Lolium multiflorum Lam.). Genotypically and phenotypically different somatic hybrid Festulolium mature flowering plants were regenerated.\\u000a \\u000a Species-specific sequences from F. arundinacea and L.

  7. Selection against somatic parasitism can maintain allorecognition in fungi.

    PubMed

    Czárán, Tamas; Hoekstra, Rolf F; Aanen, Duur K

    2014-12-01

    Fusion between multicellular individuals is possible in many organisms with modular, indeterminate growth, such as marine invertebrates and fungi. Although fusion may provide various benefits, fusion usually is restricted to close relatives by allorecognition, also called heterokaryon or somatic incompatibility in fungi. A possible selective explanation for allorecognition is protection against somatic parasites. Such mutants contribute less to colony functions but more to reproduction. However, previous models testing this idea have failed to explain the high diversity of allorecognition alleles in nature. These models did not, however, consider the possible role of spatial structure. We model the joint evolution of allorecognition and somatic parasitism in a multicellular organism resembling an asexual ascomycete fungus in a spatially explicit simulation. In a 1000-by-1000 grid, neighbouring individuals can fuse, but only if they have the same allotype. Fusion with a parasitic individual decreases the total reproductive output of the fused individuals, but the parasite compensates for this individual-level fitness reduction by a disproportional share of the offspring. Allorecognition prevents the invasion of somatic parasites, and vice versa, mutation towards somatic parasitism provides the selective conditions for extensive allorecognition diversity. On the one hand, if allorecognition diversity did not build up fast enough, somatic parasites went to fixation; conversely, once parasites had gone to fixation no allorecognition diversity built up. On the other hand, the mere threat of parasitism could select for high allorecognition diversity, preventing invasion of somatic parasites. Moderate population viscosity combined with weak global dispersal was optimal for the joint evolution of allorecognition and protection against parasitism. Our results are consistent with the widespread occurrence of allorecognition in fungi and the low degree of somatic parasitism. We discuss the implications of our results for allorecognition in other organism groups. PMID:25305337

  8. Somatic Pain Sensitivity in Children With Recurrent Abdominal Pain

    Microsoft Academic Search

    Katrin Zohsel; Johanna Hohmeister; Herta Flor; Christiane Hermann

    2008-01-01

    OBJECTIVE:Evidence is accumulating that recurrent abdominal pain (RAP) in children is associated with visceral hyperalgesia. However, it is not known whether somatic sensitivity is altered as well. Therefore, the aim of our study was to assess somatic pain sensitivity in children with RAP and healthy controls at the abdomen and a distal site (thenar).METHODS:We examined 20 children with RAP (age

  9. Attracting AID to targets of somatic hypermutation

    PubMed Central

    Tanaka, Atsushi; Shen, Hong Ming; Ratnam, Sarayu; Kodgire, Prashant

    2010-01-01

    The process of somatic hypermutation (SHM) of immunoglobulin (Ig) genes requires activation-induced cytidine deaminase (AID). Although mistargeting of AID is detrimental to genome integrity, the mechanism and the cis-elements responsible for targeting of AID are largely unknown. We show that three CAGGTG cis-elements in the context of Ig enhancers are sufficient to target SHM to a nearby transcribed gene. The CAGGTG motif binds E47 in nuclear extracts of the mutating cells. Replacing CAGGTG with AAGGTG in the construct without any other E47 binding site eliminates SHM. The CA versus AA effect requires AID. CAGGTG does not enhance transcription, chromatin acetylation, or overall target gene activity. The other cis-elements of Ig enhancers alone cannot attract the SHM machinery. Collectively with other recent findings, we postulate that AID targets all genes expressed in mutating B cells that are associated with CAGGTG motifs in the appropriate context. Ig genes are the most highly mutated genes, presumably because of multiple CAGGTG motifs within the Ig genes, high transcription activity, and the presence of other cooperating elements in Ig enhancers. PMID:20100870

  10. Impact of Early Lactation Somatic Cell Count in Heifers on Somatic Cell Counts Over the First Lactation

    Microsoft Academic Search

    S. De Vliegher; H. W. Barkema; H. Stryhn; G. Opsomer; A. de Kruif

    2004-01-01

    The objective of this study was to estimate the impact of somatic cell count in early lactation (SCCel) from Belgian dairy heifers on test-day somatic cell count (SCC) in first lactation. Geometric mean SCCel (5 to 14 d in milk (DIM)) of the 14,766 available samples was 104,000 cells\\/mL, and decreased from 178,000 at 5 DIM to 74,000 cells\\/mL at

  11. Electromagnetic induction methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electromagnetic induction geophysical methods are finding greater and greater use for agricultural purposes. Electromagnetic induction methods measure the electrical conductivity (or resistivity) for a bulk volume of soil directly beneath the surface. An instrument called a ground conductivity meter...

  12. Computer Science Induction to

    E-print Network

    Berger, Ulrich

    Computer Science Induction to Postgraduate Research Studies Ulrich Berger Head of Postgraduate Research Supervision Regulations Progression Regulations Computer Science Induction to Postgraduate Research Studies Ulrich Berger Head of Postgraduate Research Department of Computer Science Swansea

  13. Cytochalasin treatment disrupts the endogenous currents associated with cell polarization in fucoid zygotes: studies of the role of F-actin in embryogenesis

    PubMed Central

    1985-01-01

    We determined the distribution of F-actin in fucoid (Pelvetia, Fucus) embryos with nitrobenzoxadiazole-phallacidin, and studied the effect of cytochalasin upon the endogenous currents associated with cell polarization by using the vibrating probe. F-actin is not localized at the presumptive rhizoid immediately after experimental induction of the polar axis with a light gradient; however, a preferential distribution of F-actin develops at the presumptive rhizoid by the time the position of the polar axis is fixed. F-actin continues to be localized at the tip of the rhizoid after germination, except during cytokinesis, when the furrow is the only brightly staining region of the embryo. Incubation with cytochalasin can result in either an enhanced or a diminished pool of F-actin in the embryonic cortex (see Results). Cytochalasin D (100 micrograms/ml) significantly reduces the inward current at the rhizoid pole (n = 11) after a 2.5-h incubation. This drop is concentration dependent and occurs within approximately 30 min at 100 micrograms/ml and approximately 60 min at 10 micrograms/ml. Cytochalasin treatment eliminates the pulsatile component of the current. Preliminary results suggest that 100 micrograms/ml cytochalasin D prevents development of inward current at the presumptive rhizoid but does not completely delocalize this locus if added after photopolarization. We conclude that microfilaments are required for the establishment and maintenance of the pattern of endogenous currents observed during early embryogenesis. This suggests a new model for axis formation and fixation. PMID:3980581

  14. On Somatic Symptoms Measurement: The Scale for Assessment of Somatic Symptoms Revisited

    PubMed Central

    Desai, Geetha; Chaturvedi, Santhosh K.; Dahale, Ajit; Marimuthu, Palaniappan

    2015-01-01

    Background: Scale for assessment of somatic symptoms (SASS) has been widely used for assessing somatic complaints since many years. With impending changes in the classificatory system on somatoform disorders, we re- assessed the test-retest reliability and inter-rater reliability of SASS. Materials and Methods: SASS was administered twice with a gap of 24 h on 20 subjects for test retest reliability. Two clinicians assessed inter-rater reliability on 20 subjects. Kendall tau B and Cronbach's alpha were calculated from the data. Results: All of the items except burning sensation, weakness of mind and trembling had strong correlation with values >±0.40 on both test retest and inter-rater reliability; burning sensation and trembling were not reported by any subject. On inter-rater reliability the items constipation, diarrhea, lack of libido weren’t scored by any subjects. Cronbach's alpha for test retest was 0.982 and 0.840 indicating good internal consistency. Conclusion: Majority of the symptoms in SASS had high correlation in both test retest reliability as well as inter-rater reliability, however few items needs revision. PMID:25722506

  15. Inductive Reasoning and Writing

    ERIC Educational Resources Information Center

    Rooks, Clay; Boyd, Robert

    2003-01-01

    Induction, properly understood, is not merely a game, nor is it a gimmick, nor is it an artificial way of explaining an element of reasoning. Proper understanding of inductive reasoning--and the various types of reasoning that the authors term inductive--enables the student to evaluate critically other people's writing and enhances the composition…

  16. Embryogenesis of GABAergic elements in the nervous system of Eisenia fetida (Annelida, Oligochaeta).

    PubMed

    Koza, Anna; Csoknya, Mária

    2004-01-01

    The appearance and development of the GABA-immunoreactive nervous elements in the central nervous system of Eisenia fetida were studied by immunocytochemistry. The nervous system originates from the neuroectoderm situated on the ventral side of the embryo. The organization of the circumpharyngeal ring starts earlier than that of the ventral cord. In the elementary ring the first GABA-immunopositive neurons can be observed (E1 stage) around the mouth. Later the cell number gradually increases and parallel to this process the elementary ring is separeted into a superficial and a deeper portion. The brain and the subesophageal ganglion will be organized from the superficial ring, while the nervous elements of the deeper ring will give rise for the first GABA-immunoreactive elements of the stomatogastric nervous system. In the early stages of the embryogenesis the immunoreactive cells of the developing brain appear solitary, while from the stage E4 they gradually are observed in groups. According to their position, these cell groups are similar to those observed in the brain of the adult earthworms. During embryogenesis the level of the ventral cord ganglia depends on their position in the ectodermal germ bands. It means, that the more organized ganglia are near the circumpharyngeal ring, mean while less developed ganglia are situated caudally from them. By the end of the embryogenesis all ganglia of the ventral cord will be equally well organized. The nerve tracts of the ganglia are built up from contra- and ipsilateral by projected fibres. From E3 stage the medial tracts, mean while from the E4 stage the lateral tracts begin to be formed. During the next stages, more and more fibres connect to the both tracts. At hatching, the development of the central nervous system of Eisenia fetida is not completed, the process is continued during the postembryonic development. PMID:15270249

  17. Developmental origins of neurotransmitter and transcriptome alterations in adult female zebrafish exposed to atrazine during embryogenesis.

    PubMed

    Wirbisky, Sara E; Weber, Gregory J; Sepúlveda, Maria S; Xiao, Changhe; Cannon, Jason R; Freeman, Jennifer L

    2015-07-01

    Atrazine is an herbicide applied to agricultural crops and is indicated to be an endocrine disruptor. Atrazine is frequently found to contaminate potable water supplies above the maximum contaminant level of 3?g/L as defined by the U.S. Environmental Protection Agency. The developmental origin of adult disease hypothesis suggests that toxicant exposure during development can increase the risk of certain diseases during adulthood. However, the molecular mechanisms underlying disease progression are still unknown. In this study, zebrafish embryos were exposed to 0, 0.3, 3, or 30?g/L atrazine throughout embryogenesis. Larvae were then allowed to mature under normal laboratory conditions with no further chemical treatment until 7 days post fertilization (dpf) or adulthood and neurotransmitter analysis completed. No significant alterations in neurotransmitter levels was observed at 7dpf or in adult males, but a significant decrease in 5-hydroxyindoleacetic acid (5-HIAA) and serotonin turnover was seen in adult female brain tissue. Transcriptomic analysis was completed on adult female brain tissue to identify molecular pathways underlying the observed neurological alterations. Altered expression of 1928, 89, and 435 genes in the females exposed to 0.3, 3, or 30?g/L atrazine during embryogenesis were identified, respectively. There was a high level of overlap between the biological processes and molecular pathways in which the altered genes were associated. Moreover, a subset of genes was down regulated throughout the serotonergic pathway. These results provide support of the developmental origins of neurological alterations observed in adult female zebrafish exposed to atrazine during embryogenesis. PMID:25929836

  18. Assessing the influence of the entomopathogenic nematode Heterorhabditis baujardi LPP7 (Rhabiditina) on embryogenesis and hatching of the plant-parasitic nematode Meloidogyne mayaguensis (Tylenchina)

    Microsoft Academic Search

    Thiago de Freitas Ferreira; Ricardo Moreira Souza; Claudia Dolinski

    2011-01-01

    Two assays were conducted to assess the influence of infective juveniles (IJs) of Heterorhabditis baujardi LPP7 on the embryogenesis and hatching of Meloidogyne mayaguensis. In the first assay, eggs were incubated in water alone or in the presence of infective juveniles, and completion of embryogenesis was evaluated 14days later. In the second assay, unhatched second-stage juveniles were incubated in distilled

  19. An automatic quantification and registration strategy to create a gene expression atlas of zebrafish embryogenesis.

    PubMed

    Castro, C; Luengo-Oroz, M A; Desnoulez, S; Duloquin, L; Fernandez-de-Manuel, L; Montagna, S; Ledesma-Carbayo, M J; Bourgine, P; Peyrieras, N; Santos, A

    2009-01-01

    In order to properly understand and model the gene regulatory networks in animals development, it is crucial to obtain detailed measurements, both in time and space, about their gene expression domains. In this paper, we propose a complete computational framework to fulfill this task and create a 3D Atlas of the early zebrafish embryogenesis annotated with both the cellular localizations and the level of expression of different genes at different developmental stages. The strategy to construct such an Atlas is described here with the expression pattern of 5 different genes at 6 hours of development post fertilization. PMID:19963501

  20. In Vitro Fertilization with Isolated, Single Gametes Results in Zygotic Embryogenesis and Fertile Maize Plants.

    PubMed Central

    Kranz, E; Lorz, H

    1993-01-01

    We demonstrate here the possibility of regenerating phenotypically normal, fertile maize plants via in vitro fertilization of isolated, single sperm and egg cells mediated by electrofusion. The technique leads to the highly efficient formation of polar zygotes, globular structures, proembryos, and transition-phase embryos and to the formation of plants from individually cultured fusion products. Regeneration of plants occurs via embryogenesis and occasionally by polyembryony and organogenesis. Flowering plants can be obtained within 100 days of gamete fusion. Regenerated plants were studied by karyological and morphological analyses, and the segregation of kernel color was determined. The hybrid nature of the plants was confirmed. PMID:12271084

  1. A Transcriptional Roadmap to the Induction of Pluripotency in Somatic Cells

    Microsoft Academic Search

    Ying Wang; Nancy Mah; Alessandro Prigione; Katharina Wolfrum; Miguel A. Andrade-Navarro; James Adjaye

    2010-01-01

    Human embryonic stem (ES) cells possess an enormous potential for applications in regenerative medicine. However, these cells\\u000a have several inevitable hurdles limiting their clinical applications, such as transplant rejection and embryo destruction.\\u000a A milestone recently achieved was the derivation of induced pluripotent stem (iPS) cells by over-expressing combinations of\\u000a defined transcription factors, namely, OCT4, SOX2, NANOG, and LIN28 or OCT4,

  2. Diverse mechanisms of somatic structural variations in human cancer genomes

    PubMed Central

    Yang, Lixing; Luquette, Lovelace J.; Gehlenborg, Nils; Xi, Ruibin; Haseley, Psalm S.; Hsieh, Chih-Heng; Zhang, Chengsheng; Ren, Xiaojia; Protopopov, Alexei; Chin, Lynda; Kucherlapati, Raju; Lee, Charles; Park, Peter J.

    2013-01-01

    Summary Identification of somatic rearrangements in cancer genomes has accelerated through analysis of high-throughput sequencing data. However, characterization of complex structural alterations and their underlying mechanisms remains inadequate. Here, applying an algorithm to predict structural variations from short reads, we report a comprehensive catalog of somatic structural variations and the mechanisms generating them, using high-coverage whole-genome sequencing data from 140 patients across ten tumor types. We characterize the relative contributions of different types of rearrangements and their mutational mechanisms, find that ~20% of the somatic deletions are complex deletions formed by replication errors, and describe the differences between the mutational mechanisms in somatic and germline alterations. Importantly, we provide detailed reconstructions of the events responsible for loss of CDKN2A/B and gain of EGFR in glioblastoma, revealing that these alterations can result from multiple mechanisms even in a single genome and that both DNA double-strand breaks and replication errors drive somatic rearrangements. PMID:23663786

  3. Functional Evaluation of ES–Somatic Cell Hybrids In Vitro and In Vivo

    PubMed Central

    Kim, Kitai; Liu, Jun; Ng, Kitwa; Daley, George Q.; Verma, Paul J.

    2014-01-01

    Abstract Embryonic stem cells (ESCs) have previously been reported to reprogram somatic cells following fusion. The resulting ES–somatic cell hybrids have been shown to adopt the transcriptional profile of ESCs, suggesting that the pluripotent program is dominant. ES–somatic cell hybrids have most characteristics of pluripotent cells in vitro; however, it remains unclear whether the somatic genome is an active partner in the hybrid cells or simply retained predominately as silent cargo. Furthermore, the functional properties of ES–somatic cell hybrids in vivo have been limited to studies on their contribution to teratomas and developing embryos/chimeras. The extent of their pluripotency remains largely unclear. Here we determined that the somatic genome is actively transcribed by generating ES–somatic cell hybrids using Rag2-deficient ESCs fused to autologous wild-type somatic cells. Rag2 expression was detected during in vitro differentiation, suggesting that the somatic genome follows the correct temporal cues during differentiation. Furthermore, ES–somatic cell hybrids maintain their tetraploid state following 4 weeks of differentiation in vivo and are immune tolerated when transferred into matched individuals. The ES–somatic cell hybrids can efficiently differentiate into hematopoietic precursors in both myeloid and lymphoid lineages in vitro, suggesting that the somatic genome is actively transcribed following cell fusion based reprogramming. However, the ES–somatic cell hybrids showed an altered hematopoietic potential following in vitro differentiation and were unable to show hematopoietic engraftment in a mouse model. PMID:24787484

  4. Dynamics and regulation of bulk milk somatic cell counts.

    PubMed Central

    Schukken, Y H; Weersink, A; Leslie, K E; Martin, S W

    1993-01-01

    Somatic cell count (SCC) in milk is inversely related to dairy cow productivity and milk quality. In an effort to improve product quality, and indirectly farm productivity, regulatory limits on somatic cell counts have been established by many of the major dairy producing countries. The purpose of this paper was to assess the impact of regulations on bulk milk somatic cell counts in Ontario and to assist producers in meeting regulatory limits through development of prediction models. Through the use of a transfer function model, provincial SCC was found to have dropped by approximately 60,000 as a result of the reduction program. Limits of the regulatory program, seasonality and herd characteristics were found through time series cross-sectional models to have an impact on prediction of SCC at the farm level, but the major influence was historical SCC levels. PMID:8490807

  5. Cytospin centrifuge in differential counts of milk somatic cells.

    PubMed

    Dulin, A M; Paape, M J; Weinland, B T

    1982-07-01

    A procedure was developed for a cytospin centrifuge to concentrate cells from milk onto microscope slides in a circle with 6 mm diameter. Differential somatic cell counts with cytospin were compared to the conventional hand smearing technique to ascertain variation in differential counts. Milk samples were from each of 30 cow quarters, 10 within each of three total milk somatic cell count ranges of less than .7, .7 to 1.5, and more than 1.5 x 10(6)/ml. Two prepared from each sample. All smears were air dried; and stained with modified Wright's stain, the first 200 cells were counted. Differential cell counts from smears prepared by the two procedures were not different. Variation between duplicate smears in differential cell counts was less for cytospin technique. Cytospin can be used to obtain rapid and accurate differential cell counts in milk over a wide range of total somatic cell counts. PMID:7050194

  6. The recent history of somatic cloning in mammals.

    PubMed

    Brem, Gottfried; Kühholzer, Birgit

    2002-01-01

    The history of somatic cell nuclear transfer (NT) in mammals is full of exciting experiments and findings regarding the technique and outcome of NT, despite only covering a period of 6 years. The production of Dolly, for the first time demonstrating cloning from an adult somatic cell, had a great impact on subsequent studies. However, the more progress we make, the more obvious it becomes how little we know about the processes during NT, specifically how reprogramming events occur. Therefore, it is certainly challenging to continue investigating every step of somatic cell NT more intensively, starting from the donor cell, (type, cell cycle, synchronization, population doublings) and continuing until the cloned offspring are born and even further, to see how and if NT has an influence on health, viability, quantitative traits, and reproduction of cloned individuals. PMID:12006157

  7. Somatic cells count in cow's bulk tank milk.

    PubMed

    Olechnowicz, Jan; Ja?kowski, Jedrzej M

    2012-06-01

    The objective of this study was therefore to present factors affecting somatic cell counts in bovine bulk milk as a result of intramammary infections as well as non-infectious factors. The paper presents also the impact of on-farm management practices on the level of bulk milk somatic cell counts and presents quality indicators in bulk tank milk. At the farm level bulk milk bacterial infection takes place through three main sources: bacterial contamination from the external surface of the udder and teats, from the surface of the milking equipment, and from mastitis microorganisms within the udder. The threshold of 200,000 cells/ml identifies bacteriological negative quarters of the udder. The counts of mammary pathogens in bulk tank milk are relatively low, on average not exceeding 1,000 cfu/ml. Environmental pathogens predominate in bulk tank milk samples with somatic cells count <300 × 10(3) ml. PMID:22230979

  8. Effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in Artemia franciscana (Anostraca)

    NASA Technical Reports Server (NTRS)

    Rosowski, J. R.; Gouthro, M. A.; Schmidt, K. K.; Klement, B. J.; Spooner, B. S.

    1995-01-01

    Cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the NASA space shuttle Discovery, flight STS-60, from 3-11 February 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. The shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. Based on the position of the cyst shell crack in the attached cyst population, the ground-control nauplii emerged mostly upward. On the shuttle in microgravity, although our method of detection of orientation would not reveal emergence toward the coverslip, the ratio of the position of the cyst shell crack in the population after hatching best fit the predicted values of a random direction for nauplii emergence. Centrifugation on earth was then used to create hypergravity forces of up to 73 g during postencystment embryogenesis and hatching. The upward orientation of emerging nauplii showed a high degree of correlation (r(2) =98.8%) with a linear relationship to the log of g, with 78.2% of the total hatching upward at 1 g and 91.0% hatching upward at 73 g.

  9. Third-harmonic generation for the study of Caenorhabditis elegans embryogenesis

    NASA Astrophysics Data System (ADS)

    Aviles-Espinosa, Rodrigo; Santos, Susana I. C. O.; Brodschelm, Andreas; Kaenders, Wilhelm G.; Alonso-Ortega, Cesar; Artigas, David; Loza-Alvarez, Pablo

    2010-07-01

    Live microscopy techniques (i.e., differential interference contrast, confocal microscopy, etc.) have enabled the understanding of the mechanisms involved in cells and tissue formation. In long-term studies, special care must be taken in order to avoid sample damage, restricting the applicability of the different microscopy techniques. We demonstrate the potential of using third-harmonic generation (THG) microscopy for morphogenesis/embryogenesis studies in living Caenorhabditis elegans (C. elegans). Moreover, we show that the THG signal is obtained in all the embryo development stages, showing different tissue/structure information. For this research, we employ a 1550-nm femtosecond fiber laser and demonstrate that the expected water absorption at this wavelength does not severely compromise sample viability. Additionally, this has the important advantage that the THG signal is emitted at visible wavelengths (516 nm). Therefore, standard collection optics and detectors operating near maximum efficiency enable an optimal signal reconstruction. All this, to the best of our knowledge, demonstrates for the first time the noninvasiveness and strong potential of this particular wavelength to be used for high-resolution four-dimensional imaging of embryogenesis using unstained C. elegans in vivo samples.

  10. Cellular dynamics during early barley pollen embryogenesis revealed by time-lapse imaging

    PubMed Central

    Daghma, Diaa Eldin S.; Hensel, Goetz; Rutten, Twan; Melzer, Michael; Kumlehn, Jochen

    2014-01-01

    Plants display a remarkable capacity for cellular totipotency. An intriguing and useful example is that immature pollen cultured in vitro can pass through embryogenic development to form haploid or doubled haploid plants. However, a lack of understanding the initial mechanisms of pollen embryogenesis hampers the improvement and more effective and widespread employment of haploid technology in plant research and breeding. To investigate the cellular dynamics during the onset of pollen embryogenesis, we used time-lapse imaging along with transgenic barley expressing nuclear localized Green Fluorescent Protein. The results enabled us to identify nine distinct embryogenic and non-embryogenic types of pollen response to the culture conditions. Cell proliferation in embryogenic pollen normally started via a first symmetric mitosis (54.3% of pollen observed) and only rarely did so via asymmetric pollen mitosis I (4.3% of pollen observed). In the latter case, proliferation generally originated from the vegetative-like cell, albeit the division of the generative-like cell was observed in few types of pollen. Under the culture conditions used, fusion of cell nuclei was the only mechanism of genome duplication observed. PMID:25538715

  11. Rice globular embryo 4 (gle4) mutant is defective in radial pattern formation during embryogenesis.

    PubMed

    Kamiya, Noriko; Nishimura, Asuka; Sentoku, Naoki; Takabe, Eriko; Nagato, Yasuo; Kitano, Hidemi; Matsuoka, Makoto

    2003-09-01

    In higher plants, the main elements of the fundamental body plan, the apical-basal and radial patterns, are established during embryogenesis. We have isolated several globular embryo (gle) mutants of rice that fail to develop any embryonic organs. We expected that these gle mutants might include mutants defective in their radial pattern formation ability. We developed two markers specifically staining the L2 and L3 layers (OsSCR and OsPNH1, respectively) and characterized the gle mutants by using these markers in addition to the already developed markers Roc1 (marker for the L1 layer), Ramy1A (marker of the L1 layer of the epithelium), and OSH1 (marker of the apical region). One of the gle mutants, gle4, expressed Roc1 and Ramy1A at the normal positions, but other markers exhibited an abnormal expression pattern; that is, both OsPNH1 and OsSCR were expressed in the central region of the embryo and OSH1 expression was not observed. Calli from the gle4 epithelium regenerated plants with abnormal morphologies. These results indicate that the GLE4 gene is involved in radial pattern formation during rice embryogenesis to differentiate the L2 and L3 layers, but is not involved in the establishment of the L1 layer or in the formation of embryonic organs. PMID:14519768

  12. Response to Nodal morphogen gradient is determined by the kinetics of target gene induction

    PubMed Central

    Dubrulle, Julien; Jordan, Benjamin M; Akhmetova, Laila; Farrell, Jeffrey A; Kim, Seok-Hyung; Solnica-Krezel, Lilianna; Schier, Alexander F

    2015-01-01

    Morphogen gradients expose cells to different signal concentrations and induce target genes with different ranges of expression. To determine how the Nodal morphogen gradient induces distinct gene expression patterns during zebrafish embryogenesis, we measured the activation dynamics of the signal transducer Smad2 and the expression kinetics of long- and short-range target genes. We found that threshold models based on ligand concentration are insufficient to predict the response of target genes. Instead, morphogen interpretation is shaped by the kinetics of target gene induction: the higher the rate of transcription and the earlier the onset of induction, the greater the spatial range of expression. Thus, the timing and magnitude of target gene expression can be used to modulate the range of expression and diversify the response to morphogen gradients. DOI: http://dx.doi.org/10.7554/eLife.05042.001 PMID:25869585

  13. Response to Nodal morphogen gradient is determined by the kinetics of target gene induction.

    PubMed

    Dubrulle, Julien; Jordan, Benjamin M; Akhmetova, Laila; Farrell, Jeffrey A; Kim, Seok-Hyung; Solnica-Krezel, Lilianna; Schier, Alexander F

    2015-01-01

    Morphogen gradients expose cells to different signal concentrations and induce target genes with different ranges of expression. To determine how the Nodal morphogen gradient induces distinct gene expression patterns during zebrafish embryogenesis, we measured the activation dynamics of the signal transducer Smad2 and the expression kinetics of long- and short-range target genes. We found that threshold models based on ligand concentration are insufficient to predict the response of target genes. Instead, morphogen interpretation is shaped by the kinetics of target gene induction: the higher the rate of transcription and the earlier the onset of induction, the greater the spatial range of expression. Thus, the timing and magnitude of target gene expression can be used to modulate the range of expression and diversify the response to morphogen gradients. PMID:25869585

  14. The Dynamics of Somatic Exocytosis in Monoaminergic Neurons

    PubMed Central

    Sarkar, Bidyut; Das, Anand Kant; Arumugam, Senthil; Kaushalya, Sanjeev Kumar; Bandyopadhyay, Arkarup; Balaji, Jayaprakash; Maiti, Sudipta

    2012-01-01

    Some monoaminergic neurons can release neurotransmitters by exocytosis from their cell bodies. The amount of monoamine released by somatic exocytosis can be comparable to that released by synaptic exocytosis, though neither the underlying mechanisms nor the functional significance of somatic exocytosis are well understood. A detailed examination of these characteristics may provide new routes for therapeutic intervention in mood disorders, substance addiction, and neurodegenerative diseases. The relatively large size of the cell body provides a unique opportunity to understand the mechanism of this mode of neuronal exocytosis in microscopic detail. Here we used three photon and total internal reflection fluorescence microscopy to focus on the dynamics of the pre-exocytotic events and explore the nature of somatic vesicle storage, transport, and docking at the membrane of serotonergic neurons from raphe nuclei of the rat brain. We find that the vesicles (or unresolved vesicular clusters) are quiescent (mean square displacement, MSD ?0.04??m2/s) before depolarization, and they move minimally (<1??m) from their locations over a time-scale of minutes. However, within minutes of depolarization, the vesicles become more dynamic (MSD ?0.3??m2/s), and display larger range (several ?m) motions, though without any clear directionality. Docking and subsequent exocytosis at the membrane happen at a timescale (?25?ms) that is slower than most synaptic exocytosis processes, but faster than almost all somatic exocytosis processes observed in endocrine cells. We conclude that, (A) depolarization causes de-tethering of the neurotransmitter vesicles from their storage locations, and this constitutes a critical event in somatic exocytosis; (B) their subsequent transport kinetics can be described by a process of constrained diffusion, and (C) the pre-exocytosis kinetics at the membrane is faster than most other somatic exocytosis processes reported so far. PMID:23133421

  15. Comparison and Validation of Somatic Mutation Callers - Andrey Sivachenko, TCGA Scientific Symposium 2011

    Cancer.gov

    Home News and Events Multimedia Library Videos Comparison and Validation of Somatic Mutation Callers - Andrey Sivachenko Comparison and Validation of Somatic Mutation Callers - Andrey Sivachenko, TCGA Scientific Symposium 2011 You will need Adobe

  16. Somatic complaints in older adults: aging process or symptoms of depression 

    E-print Network

    Gentry, Ruth Anne

    2013-02-22

    This study examined the efficacy of somatic symptoms on a new measure of depression designed specifically for older adults. Resent research has shown somatic symptoms to be accurate predictors of depression in older adults, yet they have been...

  17. Sanger Institute: Catalogue of Somatic Mutations in Cancer

    NSDL National Science Digital Library

    The Catalogue of Somatic Mutations in Cancer (COSMIC) was designed by the Sanger Institute to house and exhibit information about somatic mutation and associated details and "contains information relating to human cancers." The COSMIC database draws on information from the primary literature, and allows users to browse by gene or tissue. In order to present users with "a consistent view of the data a histology and tissue ontology has been created and all mutations are mapped to a single version of each gene." The COSMIC site also links to other Sanger Institute projects such as the Cancer Genome Project. Links are provided to a number of other database resources as well.

  18. Genotoxic effects of two-generational selenium deficiency in mouse somatic and testicular cells.

    PubMed

    Graupner, Anne; Instanes, Christine; Andersen, Jill M; Brandt-Kjelsen, Anicke; Dertinger, Stephen D; Salbu, Brit; Brunborg, Gunnar; Olsen, Ann-Karin

    2015-03-01

    Many studies have investigated genotoxic effects of high Se diets but very few have addressed the genotoxicity of Se deprivation and its consequences in germ cells and none in somatic cells. To address these data gaps, C57BL/6 male mice were subjected to Se deprivation starting in the parental generation, i.e. before conception. Mice were given a diet of either low (0.01mg Se/kg diet) or normal (0.23mg Se/kg diet) Se content. Ogg1-deficient (Ogg1 (-/-) ) mice were used as a sensitive model towards oxidative stress due to their reduced capacity to repair oxidised purines. Ogg1 (-/-) mice also mimic the repair characteristics of human post-meiotic male germ cells which have a reduced ability to repair such lesions. The genotoxicity of Se deficiency was addressed by measuring DNA lesions with the alkaline single cell gel electrophoresis (+ Fpg to detect oxidised DNA lesions) in somatic cells (nucleated blood cells and lung cells) and male germ cells (testicular cells). Total Se concentration in liver and GPx activity in plasma and testicular cells were measured. Gene mutation was evaluated by an erythrocyte-based Pig-a assay. We found that Se deprivation of F1 from their conception and until early adulthood led to the induction of DNA lesions in testicular and lung cells expressed as significantly increased levels of DNA lesions, irrespective of the mouse genotype. In blood cells, Se levels did not appear to affect DNA lesions or mutant cell frequencies. The results suggest that the testis was the most sensitive tissue. Thus, genotoxicity induced by the low Se diet in the spermatozoal genome has potential implications for the offspring. PMID:25358475

  19. Time to Reconsider Stem Cell Induction Strategies

    PubMed Central

    Denker, Hans-Werner

    2012-01-01

    Recent developments in stem cell research suggest that it may be time to reconsider the current focus of stem cell induction strategies. During the previous five years, approximately, the induction of pluripotency in somatic cells, i.e., the generation of so-called ‘induced pluripotent stem cells’ (iPSCs), has become the focus of ongoing research in many stem cell laboratories, because this technology promises to overcome limitations (both technical and ethical) seen in the production and use of embryonic stem cells (ESCs). A rapidly increasing number of publications suggest, however, that it is now possible to choose instead other, alternative ways of generating stem and progenitor cells bypassing pluripotency. These new strategies may offer important advantages with respect to ethics, as well as to safety considerations. The present communication discusses why these strategies may provide possibilities for an escape from the dilemma presented by pluripotent stem cells (self-organization potential, cloning by tetraploid complementation, patenting problems and tumor formation risk). PMID:24710555

  20. Mechanistic and methodological aspects of chemically-induced somatic mutation and recombination in Drosophila melanogaster.

    PubMed

    Vogel, E W; Zijlstra, J A

    1987-10-01

    This study presents the analysis of chemically-induced somatic mutations and chromosomal damage in the eye imaginal discs of Drosophila larvae, assayed later as twin (TS) and single light (LS) mosaic spots in the adult eyes. Regarding the question as to what kind of DNA alterations contribute to somatic cell mutagenicity, the approach followed here has been to investigate the possible differences in response between male (hemizygous for an X) and female (homozygous) larvae, rod-X/rod-X versus ring-X/rod-X genotypes and inversion-heterozygotes versus genotypes not carrying an inversion. The systems chosen for this analysis were the white-coral/white (wco/w) and the white+/white (w+/w) eye mosaic system. The principle findings with 12 mutagens of different modes of action are as follows: (1) At least 98% of all TS and LS induced by cisplatin (DDP) in wco/w female larvae and about 95% of those by formaldehyde (FA) appear as the result of recombinogenic activity between the two homologous X-chromosomes. The corresponding estimates for MMS, EMS and ENU are 81%, 73% and 61%, respectively. (2) The long scS1L sc8R inversion, which also contains In(1)dl-49, suppresses induction of TS to 83-93%. There was also a sharp decline in the frequency of LS in inversion heterozygotes for DDP (91%), FA (86%), MMS (52%) and EMS (47%). (3) Ethylnitrosourea (ENU) was the mutagen for which introduction of the inverted chromosome reduced only slightly (23%) the frequency of LS, indicating that the majority of them were somatic mutations (and deletions) at the white locus. (4) In w/RX females heterozygous for a ring-X chromosome, the frequency of LS was only approximately one tenth of that of the control (w+/w) group, after exposure to MMS or DDP. The explanation is that exchange processes involving the ring frequently lead to genetic imbalance with subsequent cell killing. PMID:3116423