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Callus induction and plant regeneration through somaticembryogenesis 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
The low induction rates of somaticembryogenesis (SE) in Eucalyptus\\u000a globulus hamper scaling up the process for commercialization. We analyzed the effectiveness of several media (MS, 1\\/2MS, B5, WPM,\\u000a DKW and JADS) during SE induction and expression. MS and B5 were the best media for SE induction and embling regeneration.\\u000a In general, MS was the best medium for expression, independently
A procedure for inducing somatic embryos in shoot apex explants (2 mm) excised from shoot proliferation cultures established\\u000a from adult oak trees (Quercus robur) was investigated. Embryogenesis was induced in shoot tip as well as leaf explants in three out of the five genotypes evaluated.\\u000a Somatic embryos were formed by culture in induction medium supplemented with 21.48 ?M naphthalene acetic acid and
E. Corredoira; M. T. Martínez; N. Vidal; S. Valladares; R. Mallón; A. M. Vieitez
In spite of the importance of somaticembryogenesis 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 somaticembryogenesis 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 somaticembryogenesisinduction 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 somaticembryogenesis. Our observations pointed out that induction of somaticembryogenesis 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
A protocol has been developed for the induction of somaticembryogenesis from flower explants of chamomile (Chamomilla recutita L.). The effects of several plant growth regulators [?-naphthylacetic acid (NAA), 2,4-dichlorophenoxyacetic acid, 6-benzyladenine (BA) and kinetin (Kin), alone or in combination]\\u000a and the flower type (disk or ray flower) were investigated. Both types of flowers responded to the callus and shoot
Somaticembryogenesis is an important biotechnological tool that demonstrates significant benefits\\u000a when applied to forest tree species; clonal propagation, cryostorage of valuable germoplasm and genetic\\u000a transformation are among the most promising of its applications. In this chapter, the state of the\\u000a art of somaticembryogenesis in chestnut (an important economical tree species of the genus Castanea) is assessed and discussed.
E. Corredoira; A. Ballester; F. J. Vieitez; A. M. Vieitez
Codiaeum variegatum (L) Blume cv. "Corazon de oro" and cv. "Norma" are successfully micropropagated when culture are initiated with explants taken from newly sprouted shoots. The establishment and multiplication steps are possible when 1 mg/L BA or 1 mg/L IAA and 3 mg/L 2iP are added to MS medium, according to the cultivar respectively selected.Adventive organogenesis and somaticembryogenesis are induced from leaf explants taken from in vitro buds of croton. On leaf-sectioned of "Corazon de oro" cultured in vitro, 1 mg/L BA stimulates continuous somatic embryos development and induces some shoots too. Replacing BA with 1 mg/L TDZ induces up to 100% bud regeneration in the same explants. On the other hand, leaf-sectioned of C. variegatum cv. Norma does not start somatic embryo differentiation if 1 mg/L TDZ is not added to the MS basal medium. Incipient callus is observed after 30 days of culture, and then, subculture to MS with 1 mg/L BA allows the same process to show on the "Corazon de oro" cultivar. Somatic embryos show growth arrest that is partially overcome by transfer to hormone-free basal medium with activated charcoal. Root induction is possible on basal medium plus 1 mg/L IBA. Plantlets in the greenhouse have variegated leaves true-to-type. PMID:20099102
An effective tissue culture system to regenerate Melia azedarach (Meliaceae), an important multipurpose - including ornamental value - tree, was established. The optimized protocol resulted in plant formation from cotyledon explants via organogenesis and somaticembryogenesis. Embryogenic callus induction occurred on full strength (salts and vitamins) MS medium containing 3 mg\\/L 1-naphthaleneacetic acid (NAA) and 1 mg\\/L 6-benzyladenine (BA) with
The effect of different carbohydrates was tested on early somaticembryogenesis of Hevea brasiliensis. Sucrose was replaced with maltose, fructose or glucose. Somatic embryo production was significantly higher with maltose.\\u000a With maltose, the initial yellow colour of the calli turned orange, and dry matter production after 28 days' culture was half\\u000a that obtained with sucrose. Maltose also reduced the soluble
G. Blanc; N. Michaux-Ferričre; C. Teisson; L. Lardet; M. P. Carron
Pepper (cv. New Mexico — 6 and Rajur Hirapur) plants were regenerated from immature zygotic embryos via direct somaticembryogenesis. Somatic embryos were formed directly, without any intervening callus, on the zygotic embryo apex, embryo axis and cotyledons on Murashige and Skoog's (MS) medium containing 2,4-D (418 µM), thidiazuron (10 µM) and a high concentration of sucrose (6–10%). The best
Marla L. Binzel; N. Sankhla; Sangeeta Joshi; Daksha Sankhla
The capacity for somaticembryogenesis is a remarkable property of plant cells. Somatic\\u000a embryogenesis is the process by which somatic cells develop into plants through characteristic morphological\\u000a changes, thus rendering it a good model system for studying early plant development. Most of\\u000a the important crops and grasses are recalcitrant for in vitro culturing, which hampers the development\\u000a of reliable regeneration techniques. Better
\\u000a Somaticembryogenesis (SE) is a remarkable developmental process enabling nonzygotic plant cells to form embryos and, ultimately,\\u000a fertile plants. It is an expression of totipotency. This chapter initially considers the genotypic component and the progenitor\\u000a stem cells where SE is induced to form the initial asymmetric division of the somaticembryogenesis program. These cells are\\u000a part of a stem cell
R. J. Rose; F. R. Mantiri; S. Kurdyukov; S. K. Chen; X. D. Wang; K. E. Nolan; M. B. Sheahan
An efficient protocol has been developed for regeneration of complete plants through somaticembryogenesis 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
Somaticembryogenesis 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. Somaticembryogenesis differs from zygotic embryogenesis in that it is observable, its various culture conditions can be controlled, and a lack of material is not a
Francisco R. Quiroz-Figueroa; Rafael Rojas-Herrera; Rosa M. Galaz-Avalos; Víctor M. Loyola-Vargas
Somaticembryogenesis is the developmental process by which somatic cells undergo restructuring to generate embryogenic cells. These cells then go through a series of morphological and biochemical changes that result in the formation of a somatic or non-zygotic embryo capable of regenerating plants. Somaticembryogenesis represents a unique developmental pathway that includes a number of characteristic events: dedifferentiation of cells,
An efficient regeneration protocol via somaticembryogenesis was optimized for mung bean [Vigna radiata (L.) Wilczek; cv. Vamban 1]. Primary leaf explants were used for embryogenic callus induction in MMS medium (Murashige and\\u000a Skoog salts with B5 vitamins) containing 2.0 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D), 150 mg dm?3 glutamine and 3 % sucrose. Fast growing, highly embryogenic cell suspensions were
P. Sivakumar; R. Gnanam; K. Ramakrishnan; A. Manickam
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 somaticembryogenesis 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
Angela Carra; Fabio De Pasquale; Ada Ricci; Francesco Carimi
In vitro cultures from two strains of Narcissus confusus (Amaryllidaceae) initiated from mature seeds were screened for their ability to produce alkaloids. Protocols for callus induction,\\u000a somaticembryogenesis and organogenesis were established. The alkaloid contents were determined by HPLC. Undifferentiated\\u000a calli produced small amounts of galanthamine, which increased with the degree of tissue differentiation. Scanning electron\\u000a micrographs of the cultures
In planta differentiation of somatic embryos was induced in seedlings of peanut (Arachis hypogaea L.) obtained from mature seeds germinated on a medium supplemented with thidiazuron (TDZ: N-phenyl-N1- (1,2,3 thiadiazol-yl)urea). At optimum levels of TDZ (10 µM), all germinating seeds produced embryogenic seedlings, and somatic embryos developed in the apical region and on the surface of cotyledons and hypocotyls. These
The aim of this research was to establish a long-term somatic embryogenic cultures that could be used for cryopreservation.\\u000a For the induction of somaticembryogenesis, different levels of 2,4-D as well as the combination of 2,4-D and indole-3-acetyl-l-aspartic acid (IASP) were tested on cotyledons of zygotic embryos. The somatic embryogenic cultures were established and\\u000a maintained up to 2 years through frequent
This study reports the induction of somatic embryos in Mucuna pruriens. Different explants cultured on MS medium supplemented with 11.31 µM 2,4-D produced golden yellow embryogenic callus that induced synchronized embryo development on MS basal liquid medium. Organization of pre-embryonic mass was noticed 15 d after sub culturing the callus, which progressively developed to globular, heart, torpedo and cotyledonary shaped
Indirect somaticembryogenesis 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 somaticembryogenesis.\\u000a Another cycle of somaticembryogenesis 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
Guava (Psidium guajava L.) is well known for edible fruit, environment friendly pharmaceutical and commercial products for both national and international market. The conventional propagation and in vitro organogenesis do not meet the demand for the good quality planting materials. Somaticembryogenesis for efficient micropropagation of guava (P. guajava L.) has been developed to fill up the gap. Somaticembryogenesis and plantlets regeneration are achieved from 10-week post-anthesis zygotic embryo explants by 8-day inductive treatment with different concentrations of 2,4-dichlorophenoxy acetic acid (2,4-D) on MS agar medium containing 5% sucrose. Subsequent development and maturation of somatic embryos occur after 8 days on MS basal medium supplemented with 5% sucrose without plant growth regulator. The process of somaticembryogenesis shows the highest relative efficiency in 8-day treatment of zygotic embryo explants with 1.0 mg L(-1) 2,4-D. High efficiency germination of somatic embryos and plantlet regeneration takes place on half strength semisolid MS medium amended with 3% sucrose within 2 weeks of subculture. Somatic plantlets are grown for additional 2 weeks by subculturing in MS liquid growth medium containing 3% sucrose. Well-grown plantlets from liquid medium have survived very well following 2-4 week hardening process. The protocol of somaticembryogenesis is optimized for high efficiency micropropagation of guava species. PMID:23179697
Whole plant regeneration via somaticembryogenesis was obtained in pea (Pisum sativum L.) using explants from immature embryos or shoot apex segments. The induction of somatic embryos required picloram or 2,4-D. Germination of fully-developed embryos was accomplished by subculture on medium with only cytokinin and then on medium supplemented with cytokinins in combination with a reduced auxin concentration. Plantlets obtained
Wilfried Kysely; James R. Myers; Paul A. Lazzeri; Glenn B. Collins; Hans-Jorg Jacobsen
To optimize an in vitro protocol for propagation of saffron through somaticembryogenesis, 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
The effect of GA3 on somaticembryogenesis from petiole fragments excised from micropropagated fennel plantlets was studied. Explants were maintained for 4 weeks on an induction medium containing, 2,4-d and kinetin and were then transferred to a medium devoid of these growth regulators to allow embryo development. The addition of autoclaved or filter-sterilized GA3 to the induction medium or to
In cassava, somaticembryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented\\u000a with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants\\u000a for a new cycle of somaticembryogenesis. The cotyledons undergo secondary somaticembryogenesis on both liquid and solid\\u000a Murashige and Skoog-based
The embryogenic capacity of Araujia sericifera petals and some of the factors involved in the induction of embryos was investigated.\\u000a The influence of 6-benzyladenine and ?-naphthalene acetic acid, light intensity (90 or 5 mol m-2 s-1) and silver thiosulphate (inhibitor of ethylene action) were studied. It was found that petals are an easy system in which\\u000a to induce somaticembryogenesis.
J. M. Torné; P. Rodriguez; A. Manich; I. Claparols; M. A. Santos
Background and Aims The thin cell layer (TCL) technique is based on the use of very small explants and has allowed enhanced in vitro morphogenesis in several plant species. The present study evaluated the TCL technique as a procedure for somatic embryo production and plantlet regeneration of peach palm. Methods TCL explants from different positions in the shoot apex and leaf sheath of peach palm were cultivated in MS culture medium supplemented with 0–600 µm Picloram in the presence of activated charcoal. The production of primary calli and embryogenic calli was evaluated in these different conditions. Histological and amplified fragment length polymorphism (AFLP) analyses were conducted to study in vitro morphogenetic responses and genetic stability, respectively, of the regenerated plantlets. Key Results Abundant primary callus induction was observed from TCLs of the shoot meristem in culture media supplemented with 150–600 µm Picloram (83–97 %, respectively). The production of embryogenic calli depends on Picloram concentration and explant position. The best response observed was 43 % embryogenic callus production from shoot meristem TCL on 300 µm Picloram. In maturation conditions, 34 ± 4 somatic embryos per embryogenic callus were obtained, and 45·0 ± 3·4 % of these fully developed somatic embryos were converted, resulting in plantlets ready for acclimatization, of which 80 % survived. Histological studies revealed that the first cellular division events occurred in cells adjacent to vascular tissue, resulting in primary calli, whose growth was ensured by a meristematic zone. A multicellular origin of the resulting somatic embryos arising from the meristematic zone is suggested. During maturation, histological analyses revealed bipolarization of the somatic embryos, as well as the development of new somatic embryos. AFLP analyses revealed that 92 % of the regenerated plantlets were true to type. The use of TCL explants considerably improves the number of calli and somatic embryos produced in comparison with previously described protocols for in vitro regeneration of peach palm. Conclusions The present study suggests that the TCL somaticembryogenesis protocol developed is feasible, although it still requires further optimization for in vitro multiplication of peach palm, especially the use of similar explants obtained from adult palm trees.
Steinmacher, D. A.; Krohn, N. G.; Dantas, A. C. M.; Stefenon, V. M.; Clement, C. R.; Guerra, M. P.
Summary \\u000a Kalopanax pictus (Thunb.) Nakai is a tall tree, and its wood has been used in making furniture, while its stem bark is used for medicinal\\u000a purposes. Here, we report on the micropropagation of Kalopanax pictus via somaticembryogenesis. Embryogenic callus was induced from immature zygotic embryos. The frequency embryogenic callus\\u000a induction is influenced by days of seed harvest. Callus
Somaticembryogenesis and whole plant regeneration were achieved in callus cultures derived from hypocotyl, cotyledon and leaf explants excised from seedlings of Gymnema sylvestre. Embryogenic callus was induced on Murashige and Skoog (MS) medium containing 2,4-D (0.5–5.0 µM) +BA (0.5–2.0 µM) and 2% (w\\/v) sucrose in 6–8 weeks of culture. Globular\\/heart stage embryos developed on induction medium. These embryos produced
Many important food and fibre crops have attained close to their maximum yields as a result of conventional breeding approaches and advances in agronomic and horticultural practices. The manipulation of cell and tissue cultures to produce somatic embryos efficiently is one of the keystones of the new technologies that will greatly alter the way crops are planted (as synthetic seed)
The effects of methyl jasmonate (MeJA) in relation to abscisic acid (ABA) on different phases of somaticembryogenesis were\\u000a studied in Medicago sativa L. Different concentrations of both the growth inhibitors (0.0, 0.5, 5.0, 50.0 and 500.0 ?M) were tested in five distinct phases of somaticembryogenesis, viz., induction, proliferation, differentiation, maturation\\u000a and regeneration. Like ABA, MeJA also inhibited callus induction,
Somaticembryogenesis was obtained from cotyledon and mature zygotic embryo callus cultures of Terminalia chebula Retz. Callus cultures of cotyledon and mature zygotic embryo were initiated on induction medium containing Murashige and Skoog (MS) nutrients with 1.0 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D) either 0.01 or 0.1 mg\\/l Kinetin and 30 g\\/l sucrose. Induction of somaticembryogenesis, proliferation and development was obtained through different culture
The effect of smoke saturated-water (SSW) on somaticembryogenesis was studied using geranium hypocotyl culture as a model system. Treatment of explants with 10% SSW or the inclusion of SSW with thidiazuron, a compound which induces somaticembryogenesis, enhanced the embryogenic potential of the geranium hypocotyl culture. Prolonged exposure to SSW was detrimental to embryogenesis. The SSW treatment also accelerated
Tissa Senaratna; Kingsley Dixon; Eric Bunn; Darren Touchell
An efficient procedure has been developed for inducing somaticembryogenesis from leaf cultures of potato cv. Jyothi. Leaf sections were initially cultured on 2,4-dichlorophenoxyacetic acid (2,4-D) + benzyladenine (BA) and a-naphthaleneacetic acid (NAA) + BA supplemented Murashige and Skoog (MS) media. Nodular embryogenic callus developed from the cut ends of explants on media containing 2,4-D and BA, whereas compact callus
T. JayaSree; U. Pavan; M. Ramesh; A. V. Rao; K. Jagan Mohan Reddy; A. Sadanandam
In cassava, somaticembryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants for a new cycle of somaticembryogenesis. The cotyledons undergo secondary somaticembryogenesis on both liquid and solid Murashige and Skoog-based medium supplemented with auxins. Depending on the auxin, new somatic embryos are formed after 14-30 d after which they can be used for a new cycle of somaticembryogenesis. In liquid medium, more than 20 secondary somatic embryos are formed per initial cultured embryo. In both primary and secondary somaticembryogenesis, the somatic embryos originate directly from the explants. Transfer of clumps of somatic embryos to a Gresshoff and Doy-based medium supplemented with auxins results in indirect somaticembryogenesis. The direct form of somaticembryogenesis has a high potential for use in plant propagation, whereas the indirect has a high potential for use in genetic modification of cassava. Mature somatic embryos germinate into plants after desiccation and culture on a Murashige and Skoog-based medium supplemented with benzylaminopurine (BA). Depending on the used BA concentration, plants can either be transferred either directly to the greenhouse or after using standard multiplication protocols. PMID:10890012
Five genotypes of chickpea (Cicer arietinum L.) PG1, PG5, PG12, N59 and C235 were evaluated for induction of somaticembryogenesis. Somaticembryogenesis was induced from immature cotyledons of genotypes PG12 and C235 and immature embryo axes of genotypes PG5, PG12 and C235. Genotypes N59 and PG1 showed no response. The maximum frequency of globular embryo formation occurred in cotyledonary segments
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. Somaticembryogenesis 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. Somaticembryogenesis 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 somaticembryogenesis 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
Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio
An elite Chinese cotton (Gossypium hirsutum L.) cultivar Simian-3 was chosen for tissue culture. Callus with a high frequency of somaticembryogenesis, somatic embryos, and regenerative plants was obtained. Callus was induced from three types of explants on MSB (MS salts with B 5 vitamins) medium supplemented with zeatin (ZT) only, but the percentage of callus induction and growth of
Bao-Hong Zhang; Rong Feng; Fang Liu; Qinglian Wang
We have developed a reproducible system for efficient direct somaticembryogenesis 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 somaticembryogenesis. The
An efficient plant transformation system depends, in large part, on the capability of the cells to produce somatic embryos (SEs) and to then produce plants. Improvement in somaticembryogenesis has been achieved in several Georgia and Pee Dee cotton lines with media containing various putrescine (P...
Efficient plant regeneration via somaticembryogenesis has been developed in pigeonpea. Cotyledon and leaf explants from\\u000a 10-day-old seedlings produced embryogenic callus and somatic embryos when cultured on Murashige and Skoog (MS) medium supplemented\\u000a with 10 µm thidiazuron (TDZ). Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos\\u000a into plantlets on MS basal
K. Sreenivasu; S. K. Malik; P. Ananda Kumar; R. P. Sharma
Somatic embryos isolated from mature seed-derived cotyledon cultures of cassava (Mannihot esculenta Crantz) underwent direct secondary somaticembryogenesis 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
Dynamic changes in callose content, which is deposited as a plant defense response to physiological changes, were analyzed during somaticembryogenesis in Eleutherococcus senticosus zygotic embryos plasmolyzed in 1.0 M mannitol. During plasmolysis, callose deposition was clearly observed inside the plasma membrane of zygotic embryo epidermal cells using confocal laser scanning microscopy. The callose content of zygotic embryos gradually increased between 0 and 12 h plasmolysis and remained stable after 24 h plasmolysis. During eight weeks induction of somaticembryogenesis, the callose content of explants plasmolyzed for 12 h was slightly higher than explants plasmolyzed for 6 or 24 h, with the largest differences observed after 6 weeks culture, which coincided with the maximum callose content and highest number of globular somatic embryos. The highest frequency of somatic embryo formation was observed in explants plasmolyzed for 12 h. The somatic embryo induction rate and number of somatic embryos per explant were markedly different in zygotic embryos pretreated with plasmolysis alone (78.0%, 43 embryos per explant) and those pretreated with plasmolysis and the callose synthase inhibitor 2-deoxy-d-glucose (11.5%, 8 embryos per explant). This study indicates that callose production is required for somaticembryogenesis in plasmolyzed explants.
The effect of the explant position on the donor plant, illumination and explant pretreatment with high cytokinin concentrations on the induction, proliferation and development of somatic embryos from young, fully expanded leaves of chilli pepper (Capsicum annuum L.) was investigated. Explants were cultured either directly on a solid Murashige and Skoog medium supplemented with 9?M 2,4-dichlorophenoxyacetic acid+12.9?M 6-benzyladenine or incubated
S Kintzios; J. B Drossopoulos; E Shortsianitis; D Peppes
Immature soybean (Glycine max (L.) Merr) embryos, or cotyledons isolated from them, were cultured on modified MS medium containing B5 vitamins and NAA (50 µM) to induce somaticembryogenesis. The effects of media variables, dissection treatments and light conditions were investigated in this system. The efficiency of embryogenesis increased as sugar concentration decreased from 12 to 1.5%; sucrose and glucose
Paul A. Lazzeri; David F. Hildebrand; Glenn B. Collins
A method for plant regeneration of Iris via somaticembryogenesis is described. Root and leaf pieces from in vitro-grown plants of several genotypes of rhizomatous Iris sp. were cultured in vitro. Callus induction occurred only on root cultures incubated under low light intensity (35 µmol m-2 s-1) on two induction media containing 2,4-D (4.5 or 22.5 µM), NAA (5.4 µM)
Genevičve Laublin; Hargurdeep S. Saini; Mario Cappadocia
Somaticembryogenesis offers great potential in plant propagation, long-term germplasm conservation, and as a suitable model system for deciphering early events during embryogenesis. The up-regulation and ectopic expression of a SOMATICEMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) gene has been shown to mark and enhance embryogenic competence in somatic cells of model plant species. We have cloned and characterised a SERK gene (StSERK1) from potato (Solanum tuberosum L.), an important crop plant. Sequence analysis of StSERK1 revealed high levels of similarity to other plant SERKs, as well as a conserved intron/exon structure which is unique to members of the SERK family. Furthermore, StSERK clustered most closely with SERK gene family members such as MtSERK1, CuSERK1, AtSERK1, and DcSERK, implicated in evoking somaticembryogenesis. Monitoring of SERK expression during progression of potato somaticembryogenesis revealed increased StSERK expression during the induction phase. Subsequently, during the embryo transition phases, StSERK expression was unchanged and did not vary among embryo-forming and inhibitory conditions. However, in isolated somatic embryos StSERK expression was again up-regulated. In other plant parts (leaves, true potato seeds, microtubers and flower buds), StSERK showed different levels of expression. Expression analysis suggests that the isolated StSERK could be a functional SERK orthologue. The possible role of SERK as a marker of pluripotency, rather than embryogenesis alone, is discussed. PMID:18491133
Repetitive embryogenesis of Ocotea catharinensis from globular\\/early cotyledonary somatic embryos was successfully supported by WPM supplemented with 22.7 g l?1 sorbitol, 20 g l?1 sucrose, 400 mg l?1 glutamine and 2 g l?1 Phytagel. The best medium to induce repetitive embryogenesis in cotyledonary somatic embryos was half strength WPM supplemented\\u000a with 20 g l?1 sucrose, 400 mg l?1 glutamine, 1.5
Alessandra dos Santos Olmedo; Geraldine de Andrade Meyer; Jonice Macedo; Wagner de Amorim; Ana Maria Viana
The subject of this study is inducing somaticembryogenesis in the callus of Lyciumbarbarum L. and determining hydrogen peroxide in somaticembryogenesis. First of all, the activities of three antioxidant enzymes (SOD, peroxidase, catalase) in different stages of somaticembryogenesis were determined. The result showed that the activity of SOD gradually increased in the early days of differentiation culture and
Cui Kairong; Xing Gengsheng; Liu Xinmin; Xing Gengmei; Wang Yafu
Macaw palm (Acrocomia aculeata) is an oleaginous palm tree that is highly productive and adapted to semiarid ecosystems, which oil can be used to produce biodiesel. Such characteristics make macaw palm a potential crop to be used by farmers from semi-arid regions, but its propagation is still problematic. This paper reports the first description of somaticembryogenesis for macaw palm
Elisa Ferreira Moura; Sérgio Yoshimitsu Motoike; Marília Contin Ventrella; Adauto Quirino de Sá Júnior; Mychelle Carvalho
Twelve cacao (Theobroma cacao) clones propagated by grafting and somaticembryogenesis 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 ...
Oplopanax elatus is a medicinal plant on the verge of extinction because of overexploitation. In the present study, the effects of various factors on enhancing somaticembryogenesis and plantlet conversion were studied. Mature seeds were collected from a total of 13 plants from 4 mountains in South Korea, and the genetic distances were calculated to analyze the effect of genotype on somaticembryogenesis. Results of cluster analysis and the unweighted-pair-group method with arithmetic mean of 13 genotypes indicated the presence of 3 main groups. Both genotype and explant type affected the induction of somatic embryos (SEs). Sorak 2 and root were found to be the most suitable genotype and explant type, respectively, for SE induction in O. elatus. Among the different types of carbon sources tested, 5% sucrose induced the maximum number of SEs. The formation and development of SEs were significantly influenced by culture density; thus, 10 mg embryonic callus was found to be the most suitable for SE induction. The highest rates of germination and SE conversion were obtained in a germination medium containing 1.8 gelrite and 3.2 g·l(-1) agar. In addition, 80% of the plantlets that were transplanted into artificial soil acclimatized successfully. Thus, our results showed that the percentage survival of O. elatus during in vitro proliferation could be increased by optimizing to the somaticembryogenesis system. PMID:24024109
Moon, Heung-Kyu; Kim, Yong-Wook; Hong, Yong-Pyo; Park, So-Young
Summary Three auxin-type herbicides, namely 2.4-dichlorophenoxyacetic acid (2,4-D), (4-chlorophenoxy)acetic acid 2-(dimethylamino)ethyl\\u000a ester (centrophenoxine), and quinolinecarboxylic acid (quinclorac) induced direct somaticembryogenesis in seed-derived zygotic\\u000a embryo explants of sweet pepper (Capsicum annuum L.) when added to Murashige and Skoog medium with 200 mM sucrose. Optimum concentrations for embryogenesisinduction were 0.40–0.45 mM and 1.15–1.30 ?M for 2.4-D and centrophenoxine, respectively (in the
Benjamin Steinitz; Mustafa Küsek; Yona Tabib; Ilan Paran; Aaron Zelcer
Callus induction, somaticembryogenesis 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
Maurizio Sajeva; Angela Carra; Fabio de Pasquale; Francesco Carimi
Callus induction, somaticembryogenesis and plant regeneration were obtained in six different citrus species [Citrus deliciosa Ten. (cv 'Avana'), C.limon (L.) Burm. (cv 'Berna'), C.madurensis Lour. (cv 'CNR P9'), C.medica L. (cv 'Cedro di Trabia'), C.tardiva Hort. ex Tan. (cv 'CNR P6'), C.sinensis (L.) Osb. (cv 'Ugdulena 7')] from cultures of pistil transverse thin cell layer explants [(t)TCL]. Explants were
Immature embryos are the best explants for induction of somaticembryogenesis. However, precocious germination of these explants is a difficult problem facing this technology in certain wheat (Triticum aestivum L.) cultivars. To overcome this problem, spikes were harvested at 10–14 days post?anthesis, sterilised, and stored under two different conditions (4°C for 4, 7, and 10 days and 8°C for 4,
Ochna integerrima is a medicinal and ornamental plant in Southeastern Asia. It has been listed as a rare and endangered species in China. Here\\u000a we studied the effects of plant growth regulators and their concentrations on the induction of somaticembryogenesis and shoot\\u000a organogenesis from leaf and shoot explants of O. integerrima for the first time. Cytokinins played a crucial
Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somaticembryogenesis. 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 somaticembryogenesis which were
Cui Kairong; Xing Gengsheng; Qin Lin; Liu Xinmin; Wang Yafu
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, somaticembryogenesis was accompanied by
Summary Leaf segments of the orchid sp. Phalaenopsis ‘Little Steve’ were used as explants testing the effects of 2,4-dichlorophenoxyacetic acid (2,4-D; 0.45, 2.26, 4.52 ?M), 6-furfurylaminopurine (kinetin; 2.32, 4.65, 13.95 ?M), N6-benzyladenine (BA; 2.22, 4.44, 13.32 ?M), and 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ; 2.27, 4.54, 13.62?M) on the induction of direct somaticembryogenesis. After 20–30 d of culture in darkness, clusters of somatic embryos
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. Somaticembryogenesis, 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 somaticembryogenesis of the selected medicinal plant.
Saha, P.; Raychaudhuri, S.; Mishra, D.; Chakraborty, A.; Sudarshan, M.
An efficient protocol was established for regeneration of Desmodium motorium via somaticembryogenesis. 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
Indirect somaticembryogenesis is effective at eliminating the most important viruses affecting grapevines. Accordingly, this\\u000a technique was tested as a method for eradicating two widespread viroids, Grapevine yellow speckle viroid 1 (GYSVd-1) and Hop stunt viroid (HSVd), from four grapevine cultivars. Both viroids were detected by RT-PCR in grapevine floral explants used for initiating\\u000a embryogenic cultures, as well as in
Giorgio Gambino; Beatriz Navarro; Rosalina Vallania; Ivana Gribaudo; Francesco Di Serio
Somaticembryogenesis (SE) offers advantages in tree breeding due to the genetic gain improvements that can be realized through selection and production of elite (clonal) lines. Additionally, it is a platform through which value-added traits can be introduced via genetic engineering.At CellFor considerable effort has been directed towards the improvement of SE protocols for coniferous species, with significant focus placed
David R. Cyr; Stephen M. Attree; Yousry A. El-Kassaby; David D. Ellis; Dan R. Polonenko; Ben C. S. Sutton
Olive is one of the most important oil crops in the Mediterranean area. Biotechnological improvement of this species is hampered\\u000a by the recalcitrant nature of olive tissue regeneration in vitro. In this investigation, we have developed an efficient regeneration\\u000a system for juvenile olive explants via somaticembryogenesis. Embryogenic cultures were obtained at a rate of 25% by culturing\\u000a isolated radicles from
Sergio Cerezo; José A. Mercado; Fernando Pliego-Alfaro
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 somaticembryogenesis 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.
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 somaticembryogenesis 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
Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somaticembryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 microM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somaticembryogenesisinduction medium containing 5 microM abscisic acid, followed by plant regeneration medium (with 5 microM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somaticembryogenesis including orientation, polarization and elongation of the embryos. PMID:16902798
Perera, Prasanthi I P; Hocher, Valerie; Verdeil, Jean Luc; Doulbeau, Sylvie; Yakandawala, Deepthi M D; Weerakoon, L Kaushalya
Camellia nitidissima Chi (Theaceae) is a world-famous economic and ornamental plant with golden-yellow flowers. It has been classified as one of the rarest and most endangered plants in China. Our objective was to induce somaticembryogenesis, shoot organogenesis and plant regeneration for C. nitidissima. Three types of callus (whitish, reddish and yellowish) were induced from immature cotyledons on improved woody plant medium (WPM) with different plant growth regulators (PGRs). Among the callus, whitish callus was induced by 4.5 ?M 2,4-dichlorophenoxyacetic acid (2,4-D) and reddish and yellowish callus were induced by strongly active cytokinins, thidiazuron (TDZ) or 6-benzylaminopurine (BAP), singly or combined with weakly active auxin, ?-naphthaleneacetic acid (NAA). The embryogenic callus could differentiate into somatic embryos, nodular embryogenic structures (large embryo-like structures) or adventitious shoots depending on the PGR used in WPM. BAP was best for adventitious buds and zeatin was best for somaticembryogenesis while kinetin (Kt) was best for the formation of nodular embryogenic structures. The three regeneration pathways often occurred in the same embryogenic callus clumps. Most shoots (80.0%) developed roots in WPM supplemented with 24.6 ?M IBA and 0.3 ?M NAA while 47.5% of somatic embryos could germinate directly and develop into plantlets on induction medium supplemented with 0.9 ?M BAP and 0.1 ?M NAA. The nodular embryogenic structures could be sub-cultured and cyclically developed in one of two differentiation pathways: shoot organogenesis or somaticembryogenesis. Plantlets derived from shoot buds rooted and somatic embryos germinated when transplanted into soil in a greenhouse; 66.7% of plantlets from shoot culture and 78.6% of plantlets from somatic embryos survived after 8 weeks' acclimatization. PMID:23790533
Lü, Jinfeng; Chen, Rong; Zhang, Muhan; da Silva, Jaime A Teixeira; Ma, Guohua
The effects of photoperiod, light quality and end-of-day (EOD) phytochrome photoconversion on somaticembryogenesis (SE) of Araujia sericifera petals have been studied. Petals from immature flowers were cultured under 8- and 16-h photoperiods using Gro-lux fluorescent lamps. The photon fluence rate was 90-100 µmol m-2 s-1 and the red (R):far-red (FR) ratio was 98. R, FR, R followed by FR (R-FR) and FR followed by R (FR-R) light treatments were applied for 3 weeks at the end of the photoperiods. In a set of experiments, DL-alpha-difluoromethylarginine (DFMA) or methylglyoxal bis(guanylhydrazone) (MGBG), both inhibitors of polyamine biosynthesis, were added to the culture medium in order to study the involvement of polyamine metabolism. The level of SE was the same in long (LD) and short (SD) days. Thus, the light effect was accomplished after 8 h. All EOD treatments that decreased the Pfr level inhibited SE when applied after SD, but not after LD. The FR-R treatment after LD caused an additional stimulatory effect on SE, even in the presence of polyamine inhibitors. DFMA inhibited SE in both SD and LD, but MGBG did not modify SE in either SD or LD. The R, FR and R-FR treatments did not alter the level of SE when applied after LD in the presence of DFMA or MGBG. However, these treatments decreased SE after SD when the medium contained polyamine inhibitors. Our results suggest that Gro-lux lamps, which produce an extremely high R:FR ratio, promote SE in A. sericifera and a timing response to phytochrome photoconversion during photoperiodic induction. Thus, our data corroborate the involvement of phytochromes and polyamines in SE in A. sericifera, which responded as a light-dominant long-day plant. PMID:11240926
Torné, Josep M.; Moysset, Luisa; Santos, Mireya; Simón, Esther
The characterization of cellular changes that occur during somaticembryogenesis 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
Rocha, Diego Ismael; Vieira, Lorena Melo; Tanaka, Francisco André Ossamu; da Silva, Luzimar Campos; Otoni, Wagner Campos
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 somaticembryogenesis. 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
Somaticembryogenesis of cucumber was affected by auxin and light during the induction phase. In the light, 2,4-dichlorophenoxyacetic\\u000a acid (2,4-D) alone induced little embryogenesis, while combined with naphthaleneacetic acid (NAA) it induced 1.25 somatic\\u000a embryos (SEs) per callus. In the dark 2,4-D alone induced 5 times more SEs per callus.
A direct somaticembryogenesis and secondary embryogenesis protocol was developed for seven cereal species, thus providing a new vista for in vitro plant genetic transformation or propagation. This paper describes a novel process that has been successfully developed for efficient regeneration of a wide range of cereal species and genotypes. This tissue culture and regeneration system does not require formation
F. Eudes; S. Acharya; A. Laroche; L. B. Selinger; K.-J. Cheng
A simple and efficient method for high frequency somaticembryogenesis and plant regeneration from hypocotyl-derived cultures and suspension cultures of Gossypium klotzschianum Anderss, a wild, diploid species of cotton is described here. Embryogenic cultures were induced from hypocotyl sections on MSB medium with 0.9 µM 2,4-D and 2.32 µM kinetin. MSB medium containing 0.045 µM 2,4-D, 0.93 µM kinetin, 2.46
Yuqiang Sun; Xianlong Zhang; Shuangxia Jin; Shaoguang Liang; Yichun Nie
Background Somaticembryogenesis (SE) is an asexual propagation pathway requiring a somatic-to-embryonic transition of differentiated\\u000a somatic cells toward embryogenic cells capable of producing embryos in a process resembling zygotic embryogenesis. In chicory,\\u000a genetic variability with respect to the formation of somatic embryos was detected between plants from a population of Cichorium intybus L. landrace Koospol. Though all plants from this population
Sylvain Legrand; Theo Hendriks; Jean-Louis Hilbert; Marie-Christine Quillet
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 somaticembryogenesis, 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.
Desai, N. S.; Joseph, D.; Suprasanna, P.; Bapat, V. A.
Procedures for somaticembryogenesis (SE) in in vitro culture of spring snowflake have been developed from different types of explants like scales and leaves isolated from bulbs, ovaries and fruits. Various plant growth regulators were tested including a cytokinin--benzyladenine (BA) and various concentrations of the exogenous auxins 3,6-dichloro-2-methoxybenzoic acid (Dicamba), 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-amino-3,5,6-trichloropicolinic acid (Picloram). Fruit explants, cultured on medium containing Picloram and BA, ensured the highest percentage of callusing and such calli were most efficient in inducing somatic embryos. The addition of abscisic acid (ABA) in combination with polyethylene glycol (PEG) stimulated somatic embryo maturation. Torpedo-stage embryos developed into plants in the presence of BA and 1-naphthaleneacetic acid (NAA). The formation and growth of adventitious bulbs required that the plantlets be chilled at 5 degrees C in the dark for 6 weeks. After chilling, the bulbs grew well in darkness 25 degrees C. High sucrose concentration in the medium was necessary for obtaining large bulbs. PMID:20099105
A simple method to induce somaticembryogenesis 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
Availability of explants with adequate embryogenic competence is one of the most important limitations for the development of regenerable cell suspensions in banana. To increase the number and ease of accessibility to potentially embryogenic explants, a novel methodology is described by which young male flower clusters isolated from adult plants are induced to form new flower buds and proliferate in vitro. Different concentrations of the plant growth regulator thidiazuron (TDZ) induced inflorescence proliferation, which could be maintained over time as a continuous source of young flower buds. Intensity of proliferation was evaluated during successive subcultures. At the third cycle of proliferation, the highest multiplication rate (2.89) was obtained on the medium containing 5 microM TDZ. Newly generated floral tissues were assessed for embryogenic competence, resulting in an average embryogenic frequency of 12.5%. The observed embryogenic capacity, together with the recurrent availability of immature flowers, allowed for the direct initiation of cell suspensions from bulked explant cultures. Regular observation and regeneration tests during the development of suspended cell cultures confirmed their embryogenic condition. Produced embryos successfully matured and germinated to regenerate hundreds of somatic in vitro plants. PMID:18259756
Pérez-Hernández, Juan Bernardo; Rosell-García, Purificación
Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstocks, and it is very useful also for breeding and germplasm preservation.In this chapter, two protocols regarding organogenesis of a rootstock and somaticembryogenesis of a cultivar have been described. PMID:23179693
The morphological fidelity of the olive plants propagated through axillary buds, microplants and somaticembryogenesis, somatic plants was evaluated. Thirty-two morphological traits were used to characterize the tissue culture propagated olive plants. The microplants showed very high phenotypic similarity compared to plants produced by conventional cutting propagation method. The somatic plants exhibited variant morphological stable phenotypes, among somaclonal population two
We have developed a reliable and high-frequency system of transformation and regeneration via somaticembryogenesis (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
Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somaticembryogenesis and regeneration.\\u000a Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were\\u000a used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison\\u000a with immature zygotic embryos. Moreover, differences
Pascal Lambé; Hity S. N. Mutambel; Roger Deltour; Monique Dinant
Protoplast culture and plant regeneration of the dessert banana cultivar Grande Naine (Musa spp., Cavendish sub-group AAA) were achieved through somaticembryogenesis. Protoplasts were isolated from cell suspensions at a yield of 3쎻 protoplasts\\/ml packed cell volume (0.5 g). For the induction of cell divisions, two banana cell suspensions, SF265 (AA) and IRFA903 (AA), were used as feeder layers. SF265
A. Assani; R. Haicour; G. Wenzel; F. Côte; F. Bakry; B. Foroughi-Wehr; G. Ducreux; M.-E. Aguillar; A. Grapin
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 somaticembryogenesis (ISE). In the indirect somaticembryogenesis 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 somaticembryogenesis, while a high ABA concentration (10-100? ? M) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somaticembryogenesis 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 somaticembryogenesis, 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
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 somaticembryogenesis (ISE). In the indirect somaticembryogenesis 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 somaticembryogenesis, while a high ABA concentration (10–100??M) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somaticembryogenesis 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 somaticembryogenesis, 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.
NAA and 2,4-D were compared for their ability to induce somaticembryogenesis 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,
E. Sofiari; C. J. J. M. Raemakers; E. Kanju; K. Danso; A. M. van Lammeren; E. Jacobsen; R. G. F. Visser
Somaticembryogenesis is an in vitro clonal propagation method with potential to contribute to the improvement of cacao varieties. Before using this technology\\u000a for commercial production, it is essential that somaticembryogenesis-derived plants be tested in field conditions. Therefore,\\u000a we established a field test at Union Vale Estate, Saint Lucia. Thirty- to 50-yr-old trees were selected for clonal propagation\\u000a as
Siela N. Maximova; Ann Young; Sharon Pishak; Mark J. Guiltinan
Plant regeneration via direct somaticembryogenesis from cotyledons, hypocotyls and leaves in seabuckthorn (Hippophae rhamnoides L.) was achieved. The influences of basal media, carbon sources, plant growth regulators (PGRs) with different concentrations\\u000a and combinations on embryogenesis capacity of explants were studied. The highest frequency of somatic embryos production and\\u000a germination was obtained on Schenk and Hildebrandt medium (SH) supplemented with
C. Q. Liu; X. L. Xia; W. L. Yin; J. H. Zhou; H. R. Tang
BACKGROUND: In our laboratory we use cultured chicory (Cichorium intybus) explants as a model to investigate cell reactivation and somaticembryogenesis and have produced 2 chicory genotypes (K59, C15) sharing a similar genetic background. K59 is a responsive genotype (embryogenic) capable of undergoing complete cell reactivation i.e. cell de- and re-differentiation leading to somaticembryogenesis (SE), whereas C15 is a
Anca Lucau-Danila; Laurent Laborde; Sylvain Legrand; Ludovic Huot; David Hot; Yves Lemoine; Jean-Louis Hilbert; Simon Hawkins; Marie-Christine Quillet; Theo Hendriks; Anne-Sophie Blervacq
Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somaticembryogenesis. The effect of hydrogen peroxide on synthesis of proteins during somaticembryogenesis 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
Cui Kairong; Li Ji; Xing Gengmei; Li Jianlong; Wang Lihong; Wang Yafu
Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somaticembryogenesis. The effect of hydrogen peroxide on synthesis of proteins during somaticembryogenesis 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
The possible involvement of Ca2+-mediated signaling in the induction/regulation of somaticembryogenesis from pro-embryogenic cells of sandalwood (Santalum album) has been investigated. 45Ca2+-uptake studies and fura-2 fluorescence ratio photometry were used to measure changes in [Ca2+]cyt of pro-embryogenic cells in response to culture conditions conducive for embryo development. Sandalwood pro-embryogenic cell masses (PEMs) are obtained in the callus proliferation medium that contains the auxin 2,4-dichlorophenoxyacetic acid. Subculture of PEMs into the embryo differentiation medium, which lacks 2,4-dichlorophenoxyacetic acid and has higher osmoticum, results in a 4-fold higher 45Ca2+ incorporation into the symplast. Fura-2 ratiometric analysis corroboratively shows a 10- to 16-fold increase in the [Ca2+]cyt of PEMs, increasing from a resting concentration of 30 to 50 nm to 650 to 800 nm. Chelation of exogenous Ca2+ with ethyleneglycol-bis(aminoethyl ether)-N,N?-tetraacetic acid arrests such an elevation in [Ca2+]cyt. Exogenous Ca2+ when chelated or deprived also arrests embryo development and inhibits the accumulation of a sandalwood Ca2+-dependent protein kinase. However, such culture conditions do not cause cell death as the PEMs continue to proliferate to form larger cell clumps. Culture treatment with N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide reduced embryogenic frequency by 85%, indicating that blockage of Ca2+-mediated signaling pathway(s) involving sandalwood Ca2+-dependent protein kinase and/or calmodulin causes the inhibition of embryogenesis. The observations presented are evidence to suggest a second messenger role for exogenous Ca2+ during sandalwood somaticembryogenesis.
We have established a high-frequency plant regeneration system via somaticembryogenesis from mature seeds of creeping bentgrass (Agrostis palustris Huds). The effects of 2,4-dichlorophenoxyacetic acid (2,4-D), 3.6-dichloroo-anisic acid (dicamba) and 6-benzyladenine (BA) on callus formation and embryogenesis were evaluated. Callus produced on the Murashige and Skoog (MS) (1962) medium containing 2,4-D had low embryogenic potency. In the presence of 30
Somatic embryos from immature cotyledons in peanut (Arachis hypogaea) were initiated on media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-d). Over 90% primary embryogenesis and 41–46% repetitive embryogenesis were obtained 12 weeks after initiation by maintaining embryogenic cultures on medium containing 20 mg 1-1 2,4-d. Maintenance of cultures on medium with 30 or 40 mg I-1 2,4-d resulted in lower primary and
Somaticembryogenesis (SE) is a propagation tool of particular interest for accelerating the deployment of new high-performance planting stock in multivarietal forestry. However, genetic conformity in in vitro propagated plants should be assessed as early as possible, especially in long-living trees such as conifers. The main objective of this work was to study such conformity based on genetic stability at simple sequence repeat (SSR) loci during somaticembryogenesis in maritime pine (Pinus pinaster Ait.). Embryogenic cell lines (ECLs) subjected to tissue proliferation during 6, 14 or 22 months, as well as emblings regenerated from several ECLs, were analyzed. Genetic variation at seven SSR loci was detected in ECLs under proliferation conditions for all time points, and in 5 out of 52 emblings recovered from somatic embryos. Three of these five emblings showed an abnormal phenotype consisting mainly of plagiotropism and loss of apical dominance. Despite the variation found in somaticembryogenesis-derived plant material, no correlation was established between genetic stability at the analyzed loci and abnormal embling phenotype, present in 64% of the emblings. The use of microsatellites in this work was efficient for monitoring mutation events during the somaticembryogenesis in P. pinaster. These molecular markers should be useful in the implementation of new breeding and deployment strategies for improved trees using SE. PMID:19153739
Somaticembryogenesis receptor-like kinase (SERK) belonging to the receptor-like kinases (RLKs) has been shown to be implicated in somaticembryogenesis (SE). In this study, a somaticembryogenesis receptor-like\\u000a gene CitSERK1-like was cloned and characterized from Citrus sinensis cv. ‘Valencia’, a genotype with high somaticembryogenesis capacity for over 26 years. Fifteen consecutive amino acids in\\u000a putative leucine zipper domain of CitSERK1-like
An efficient somaticembryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somaticembryogenesis (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 somaticembryogenesis (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.
Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker
Somatic embryogenic callus was initiated from in vitro-derived petiole and root explants, but not leaves, of the Floribunda rose cultivars Trumpeter and Glad Tidings following repeated subculture of callus on Schenk and Hildebrandt (SH) medium containing 2,4-dichlorophenoxyacetic acid (2,4-D). The use of a high auxin pretreatment increased the frequency of somaticembryogenesis, whilst l-proline, as a media supplement, had a
Robert Marchant; Michael R. Davey; John A. Lucas; J. Brian Power
Medicago truncatula ssp Narbonensis and four genotypes of M. truncatula Gaertn cv. Jemalong were tested for their somaticembryogenesis potential using a two-step protocol. In the first step, embryogenic\\u000a callus was induced in folioles isolated from shoots grown in vitro and cultured on Murashige and Skoog (MS) medium supplemented\\u000a with 2,4-dichlorophenoxyacetic acid and zeatin. In the second step, somatic embryos
L. O. das Neves; S. R. L. Duque; J. S. de Almeida; P. S. Fevereiro
Three different types of morphogenesis were identified in embryogenic cultures of Prunus avium grown on a proliferation medium\\u000a containing 0.54 ?M NAA, 0.46 ?M kinetin and 0.44 ?M BA: a friable hyperhydric callus, repetitive embryogenesis and an embryogenic\\u000a tissue. Translucent and white somatic embryos were produced from the three types of morphogenesis but mainly from the embryogenic\\u000a tissue. These somatic
Summary A protocol of somaticembryogenesis and plant regeneration from petiole segments of Parthenocissus tricuspidata Planch. has been developed. Embryogenic tissue was induced on B5 (Gamborg) basal medium supplemented with 2.25–9.0 ?M 2,4-dichlorophenoxyacetic acid, 500 mg l?1 casein hydrolysate (CH), and 0.1 gl?1 activated charcoal. Somatic embryos were induced on B5 medium containing various concentrations of benzyladenine (BA) (4.44,\\u000a 6.66, and
Somaticembryogenesis can efficiently foster the propagation of Theobroma cacao, but the poor quality of resulted plantlet hinders the use of this technique in the commercial scale. The current study has been initiated to systematically compare the physiological mechanisms underlying somatic and zygotic embryogenesis in T. cacao on the proteome level. About 1000 protein spots per fraction could be separated by two-dimensional isoelectric focusing/SDS PAGE. More than 50 of the protein spots clearly differed in abundance between zygotic and somatic embryos: 33 proteins spots were at least 3-fold higher in abundance in zygotic embryos and 20 in somatic embryos. Analyses of these protein spots differing in volume by mass spectrometry resulted in the identification of 68 distinct proteins. Many of the identified proteins are involved in genetic information processing (21 proteins), carbohydrate metabolism (11 proteins) and stress response (7 proteins). Somatic embryos especially displayed many stress related proteins, few enzymes involved in storage compound synthesis and an exceptional high abundance of endopeptidase inhibitors. Phosphoenolpyruvate carboxylase, which was accumulated more than 3-fold higher in zygotic embryos, represents a prominent enzyme in the storage compound metabolism in cacao seeds. Implications on the improvement of somaticembryogenesis in cacao are discussed. PMID:23178419
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
Helena Mathews; C. Schopke; R. Carcamo; P. Chavarriaga; C. Fauquet; R. N. Beachy
Various characteristics including the saponin content in the root of Bupleurum falcatum plants propagated in vitro through somaticembryogenesis of callus cultures were compared with those of the plants propagated by seeds. The asexually propagated plants had an aerial part of more uniform characteristics than those of sexually propagated ones. However, both the mean and variance of root weight of
Somaticembryogenesis of carrot (Daucus carota L.) is inhibited by the glycosylation inhibitor tunicamycin. This inhibition is reversible by the addition of correctly glycosylated glycoproteins which have been secreted into the culture medium. To identify the proteins responsible for complementation, glycoproteins present in the medium of embryo cultures were purified and tested for their activity in the tunicamycin inhibition\\/ complementation
J. H. G. Cordewener; Hiibert Booij; Hans van der Zandt; Fred van Engelen; Ab van Kammen; Sacco de Vries
Somaticembryogenesis leading to plant regeneration has been achieved in the bamboo, Dendrocalamus strictus, by culturing seeds (caryopses) on B5 basal medium supplemented with 2,4-dichlorophenoxyacetic acid. Callus cultures obtained from the embryonal end of the seeds differentiated chlorophyllous embryoids. On transfer to a germination medium (B5 liquid, sucrose, indolebutyric acid, and ? -naphthaleneacetic acid) 40% of the embryoids developed into
The present study is the first report of the establishment of embryogenic callus cultures from seedling tissue, the regeneration of plants via somaticembryogenesis and the development of a regeneration system from protoplast to plant, using three wild species of Cyclamen, Cyclamen graecum Link, Cyclamen mirabile Hildebrand, Cyclamen trochopteranthum Schwarz (syn. Cyclamen alpinum hort. Dammann ex Sprenger). The ability to
Members of the AP2 family of transcription factors, such as BABY BOOM (BBM), play important roles in cell proliferation and embryogenesis in Arabidopsis thaliana (AtBBM) and Brassica napus (BnBBM) but how this occurs is not understood. We have isolated three AP2 genes (GmBBM1, GmAIL5, GmPLT2) from somatic embryo cultures of soybean, Glycine max (L.) Merr, and discovered GmBBM1 to be homologous to AtBBM and BnBBM. GmAIL5 and GmPLT2 were homologous to Arabidopsis AINTEGUMENTA-like5 (AIL5) and PLETHORA2 (PLT2), respectively. Constitutive expression of GmBBM1 in Arabidopsis induced somatic embryos on vegetative organs and other pleiotropic effects on post-germinative vegetative organ development. Sequence comparisons of BBM orthologues revealed the presence of ten sequence motifs outside of the AP2 DNA-binding domains. One of the motifs, bbm-1, was specific to the BBM-like genes. Deletion and domain swap analyses revealed that bbm-1 was important for somaticembryogenesis and acted cooperatively with at least one other motif, euANT2, in the regulation of somaticembryogenesis and embryo development in transgenic Arabidopsis. The results provide new insights into the mechanisms by which BBM governs embryogenesis. PMID:20798978
El Ouakfaoui, Souad; Schnell, Jaimie; Abdeen, Ashraf; Colville, Adam; Labbé, Hélčne; Han, Shuyou; Baum, Bernard; Laberge, Serge; Miki, Brian
Immature zygotic embryos of ginseng produced somatic embryos on MS medium without growth regulators. However, in the culture of mature zygotic embryos, excision of the embryo was required for somatic embryo induction. Somatic embryos formed only on excised cotyledons without an embryo axis or on excised embryos without the plumule and radicle of the axis. This observation suggests that the
Somaticembryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somaticembryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal.
Kim, Yu-Jin; Lee, Ok Ran; Kim, Kyung-Tack; Yang, Deok-Chun
Somaticembryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somaticembryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal. PMID:23717148
Kim, Yu-Jin; Lee, Ok Ran; Kim, Kyung-Tack; Yang, Deok-Chun
Somatic embryos are being considered as an alternative material for in vitro germplasm conservation of sweet potato [(Ipomoea batatas (L.) Lam.)]. Picolinic acid was tested for somatic embryo production in sweet potato apical meristem tip cultures. Low level (0.2 mgl-1) of picolinic acid combined with kinetin or 6-benzylamino purine (6-BAP) (1.0 and 2.0 mgl-1) suppressed shoot growth and induced callus
Nenite V. Desamero; Billy B. Rhodes; Dennis R Decoteau; William C Bridges
Plant regeneration was achieved through direct and indirect somaticembryogenesis in Eucalyptus camaldulensis. Callus was induced from mature zygotic embryos and from cotyledon explants collected from 10, 15, 25, and 30-day-old seedlings\\u000a cultured on Murashige and Skoog (MS) basal medium supplemented with different concentrations of naphthaleneacetic acid (NAA).\\u000a Maximum callus induction from mature zygotic embryos was obtained on MS basal
The present study describes a system for efficient plant regeneration via organogenesis and somaticembryogenesis 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.
J. Vijaya Kumar; B. D. Ranjitha Kumari; G. Sujatha; Enrique Castańo
Seventy-six cultivars of alfalfa (Medicago sativa L., M. falcata L. and M. varia Martyn) were tested in vitro for their capacity to produce callus and somatic embryos. A three-step media protocol was used to survey the response of the cotyledons and hypocotyl of each genotype while the epicotyl region was conserved in order to recover highly responding genotypes. The best
Synchronization of somaticembryogenesis at high frequency is a useful system for the mass production of embryos. Many attempts have been carried out, however, it was difficult to obtain the system in which most of the initial embryogenic cells or cell clusters synchronously differentiate to embryos. In carrot suspension cultures, high frequency, synchronous embryogenesis systems (following three systems) have been
Enhanced somaticembryogenesis and plant regeneration have been obtained using young leaf bases of naked oat (Avena nuda) as explants by including salicylic acid (SA) and carrot embryogenic callus extracts (CECE) in media. A 5- and 4-fold improvement\\u000a was achieved in somaticembryogenesis and plant regeneration on the corresponding media supplemented with 0.5 mM SA and CECE\\u000a as compared to control,
A complete protocol for large-scale propagation of Dendrocalamus strictus Nees by somaticembryogenesis has been developed. Seeds cultured on agar-solidified Murashige and Skoog (MS) medium supplemented\\u000a with 2,4-dichlorophenoxyacetic acid (2,4-D; 3×10–5\\u000a m) produced embryogenic callus from proliferation of the embryo. Somatic embryos formed in vitro multiplied rapidly (two- to\\u000a five fold every 5 weeks) on semi-solid MS medium containing 2,4-D
The morphogenetic potential of node, internode and leaf explants of Brahmi [Bacopa monniera (L.) Wettst.] was investigated to develop reliable protocols for shoot regeneration and somaticembryogenesis. The explants\\u000a were excised from shoots raised from axillary buds of nodal explants cultured on Murashige and Skoog (MS) basal medium. Presence\\u000a of 6-benzylaminopurine (BA) or kinetin influenced the degree of callus formation,
BackgroundThe plant cell walls play an important role in somaticembryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development.Methodology\\/Principal FindingsDevelopmental localization of pectic homogalacturonan
Leaf explants of Phalaenopsis amabilis var. formosa formed clusters of somatic embryos directly from epidermal cells without an intervening callus within 20 – 30 d when cultured\\u000a on 1\\/2-strength modified Murashige and Skoog medium supplemented with 0.1, 1 and 3 mg dm?3 TDZ. Repetitive production of embryos involved secondary embryogenesis could be obtained by culturing segments of embryogenic\\u000a masses on
A somaticembryogenesis (SE) protocol was established for the regeneration of Lilium ledebourii (Baker) Boiss. whole plants using new vegetative bulblet microscales and transverse thin cell layers (tTCLs) of young bulblet\\u000a roots as the explant sources. Bulblets were induced from bulb scale explants cultured for at least 3 months in the dark on\\u000a Murashige and Skoog (MS) medium containing 3%
Mehdi BakhshaieMesbah Babalar; Mesbah Babalar; Masoud Mirmasoumi; Ahmad Khalighi
Real-time reverse transcriptase PCR is a powerful tool to investigate relevant changes in gene expression during plant somaticembryogenesis (S.E.); however, this method lacks ideal reference genes. To select the most stable reference genes for S.E. studies, the expression profiles of seven frequently used reference genes (18S RNA, eIF-4a, UBQ, ACTB, EF-1a, Histone H3, and 2-TUB) and functional genes (Fe-SOD,
Tissue culture techniques are useful for ex situ conservation of rare, endemic or threatened plant species. This report describes a protocol for somaticembryogenesis 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).
Jayachandran Philip Robinson; S. John Britto; V. Balakrishnan
Somatic embryos ofHevea brasiliensis can be obtained by culturing thin sections of inner tegument of seed on two successive different media, MH1 and MH3. Histological study showed that in calli cultured on non-renewed medium MH1 for 40 days, the embryogenesis process initiated on the 20th day did not produce results owing to early degeneration of the cells involved in the
A protocol has been developed for somaticembryogenesis 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,
S. Zdravkovi?-Kora?; J. Milojevic ´; Lj. Tubi?; D. ?ali?-Dragosavac; N. Miti?; B. Vinterhalter
Among the >200 members of the leucine-rich repeat receptor kinase family in Arabidopsis thaliana, only a few have been functionally characterized. Here, we report a critical function in anther development for the SOMATICEMBRYOGENESIS RECEPTOR KINASE1 (SERK1) and SERK2 genes. Both SERK1 and SERK2 are expressed widely in locules until stage 6 anthers and are more concentrated in the tapetal
Jean Colcombet; Aurelien Boisson-Dernier; Roc Ros-Palau; Carlos E. Vera; Julian I. Schroeder
The response of five Coffea canephora Pierre genotypes with regard to somaticembryogenesis was tested on media containing silver nitrate (AgNO3) and different carbohydrates (sucrose, fructose, maltose and glucose). The presence of AgNO3 caused only small modifications to the ionic equilibrium of the media. At concentrations between 30–60 µM, AgNO3 improved embryo yield for the genotypes evaluated, while higher doses
Sandra R. L. Fuentes; Maria B. P. Calheiros; Joăo Manetti-Filho; Luiz G. E. Vieira
For maximum avoidance of somaclonal variation risks, the commonly used medium for somaticembryogenesis inPhoenix dactylifera has been lowered in growth regulators and activated charcoal. When initially cultured on MS basal medium containing only\\u000a 150 mg dm?3 charcoal, 5 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D) and 5 mg dm?3 benzylaminopurine (BAP), 10 to 20% of shoot-tip explants developed into embryogenic calli.
Somatic embryos (SEs) have been produced from bulb and shoot culture leaf explants of Narcissus pseudonarcissus cvs. Golden Harvest and St. Keverne. Initial experiments with cv. Golden Harvest resulted in SEs from leaf lamina, leaf base, bulb scale and scape (flower stem) explants. Embryogenesis was induced on media with a range of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP) concentrations. There
Somaticembryogenesis was induced from mature cotyledons, hypocotyl, nodal segment, and leaf explants of two Indian cultivars of Vigna radiata (L.) Wilczek on Murashige and Skoog’s medium supplemented with several combinations of growth regulators. The greatest response was obtained with the combination 1.809?M 2,4-dichlorophenoxyacetic acid (2,4-D) with 3.555?M benzyl adenine (BA). Better response was obtained when cultures were incubated under
Prathibha Devi; P Radha; L Sitamahalakshmi; D Syamala; S Manoj Kumar
A protocol for plant regeneration from protoplasts of Musa acuminata cv. Mas (AA) via somaticembryogenesis was developed. Viable protoplasts were isolated from embryogenic cell suspensions\\u000a at a yield of 1.2 × 107 protoplasts\\/ml packed cell volume (PCV). Liquid and feeder layer culture systems with medium-A and medium-B were used for\\u000a protoplast culture. In liquid culture system, medium-B was more efficient for
Somaticembryogenesis was obtained from immature cotyledon explants that were cultured on half-strength Murashige and Skoog (MS) salts and vitamins with 5.4 uM naphthaleneacetic acid (NAA) and 0.2 uM thidiazuron (TDZ) plus a 4x4 factorial combination of 0,9.8, 34.6, or 49.2 uM indole-3-butyric acid ...
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
Somaticembryogenesis of Panax ginseng CA Meyer was initiated from suspension aggregates of an embryogenic callus, in a liquid medium consisting of half strength Murashige and Skoog (1962) supplemented with the synthetic auxin benzoselenienyl-3 acetic acid. The addition of spermidine to this initiation medium significantly increased the production of somatic embryos. In this case, the total polyamine content of the
Marta Monteiro; Claire Kevers; Jacques Dommes; Thomas Gaspar
Embryogenic cultures of Panax ginseng were established without using phytohormones. Somatic embryos developed from the roots of an in vitro seedling and from excised leaf and petiole segments cultured in half-macro-salt strength Murashige and Skoog medium. Excised leaf and petiole segments were obtained from in vitro germinated seedlings. Plantlets were subsequently obtained from developing somatic embryos in phytohormone-free media. Shoot formation from somatic embryos was influenced by light intensity. The rate of growth and frequency of embryogenesis were improved when cut-up embryogenic tissues were inoculated into liquid media in the dark. The ginsenoside contents of a 4 year-old field-cultivated root, seedlings from zygotic embryos, somatic embryos and embryogenic tissues were determined and compared. Somatic embryos contained 1.7 times the amount of ginsenoside Rb1 and 2.3 times the amount of ginsenoside Re compared to seedlings from zygotic embryos. Ginsenoside Rd, which was absent in the seedlings derived from zygotic embryos, was detected in somatic embryos. Higher ginsenosides Rd and Rg1 levels were found in embryogenic tissues grown on solid media than in tissues grown in liquid media. The total ginsenoside yields, including the ginsenosides Rb1 and Rg1 levels, of cut-up embryogenic tissues, were higher than those of clump tissues. PMID:10859948
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods. PMID:16532531
Rao, Abdul Qayyum; Hussain, S Sarfraz; Shahzad, M Saqib; Bokhari, S Yassir Abbas; Raza, M Hashim; Rakha, Allah; Majeed, A; Shahid, A Ali; Saleem, Zafar; Husnain, Tayyab; Riazuddin, S
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.
Rao, Abdul Qayyum; Hussain, S. Sarfraz; Shahzad, M. Saqib; Bokhari, S. Yassir Abbas; Raza, M. Hashim; Rakha, Allah; Majeed, A.; Shahid, A. Ali; Saleem, Zafar; Husnain, Tayyab; Riazuddin, S.
The inter-relationship between exogenous calcium (Ca2+) during cold pretreatment and cold-enhanced somaticembryogenesis 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
An efficient method was established for high frequency somaticembryogenesis and plant regeneration from callus cultures of a hybrid of sympodial orchid (Oncidium ‘Gower Ramsey’). Compact and yellow–white embryogenic calli formed from root tips and cut ends of stem and leaf segments on 1\\/2 MS  basal medium supplemented with 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ, 0.1–3 mg\\/l), 2,4-dichlorophenoxyacetic acid (2,4-D, 3–10 mg\\/l) and
Cultures were initiated from immature seeds derived from controlled pollinations between two sweetgum species (Liquidambar styraciflua and L. formosana) cultured on two induction media supplemented with 2,4-dichlorophenoxyacetic acid. Repetitive embryogenic cultures capable of producing somatic seedlings were obtained from 2% of the 1,020 seeds cultured, representing nine crosses between L. styraciflua and L. formosana. Hybrid genotypes of somatic seedlings were
Somaticembryogenesis and further plant regeneration were observed using zygotic embryos, young inflorescences and young leaves\\u000a ofEuterpe edulis (Palmae) as explants. Both for the cultures of zygotic embryos and inflorescences, activated charcoal in the medium was essential\\u000a for the establishment of viable cultures. Embryogenesis was induced by using a gelled basal medium with MS or Euwens salts\\u000a supplemented by high
Summary Anthers and ovaries of six grapevine cultivars (three Vitis vinifera L., two V Labruscana L. H. Bailey, and one complex hybrid) were extracted from flower buds over 2 yr and cultured on three media reported to promote\\u000a somaticembryogenesis in Vitis tissues. The highest percent embryogenesis from the hybrid ‘Chancellor’ and V. vinifera ‘Chardonnay’, ‘Merlot’, and ‘Pinot Noir’ occurred on
Julie R. Kikkert; Michael J. Striem; José R. Vidal; Patricia G. Wallace; John Barnard; Bruce I. Reisch
Plant regeneration and somaticembryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somaticembryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets.
Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah
Plant regeneration and somaticembryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somaticembryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F(1) plantlets confirmed the presence of the hybrid plantlets. PMID:23235330
Azad, Md Abul Kalam; Rabbani, Md Golam; Amin, Latifah
.Using immature zygotic embryos as explants, we have developed an efficient method for somaticembryogenesis in three germplasm accessions collected from China, India and Indonesia. Indirect somaticembryogenesis 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
• Background and Aims The date palm is a dioecious perennial species of the Arecaceae for which in vitro micropropagation is essential to ensure the renewal of palm plantations. This study presents a histocytological analysis of the traditional Mauritanian Amsekhsi cultivar beginning from the initial callogenesis and continuing up to the establishment of the cellular embryogenic cell suspensions. The formation of somatic embryos and their development into rooted plants are also described. • Methods Foliar segments of seedlings cultured in the presence of 2,4-D produced primary calli that were chopped to produce fine friable granular calli that subsequently produced cellular suspensions when transferred to liquid medium. The somatic proembryos that developed after removal of the 2,4-D were plated on agar medium where they developed into rooted plants. Thin sections of tissue fragments taken at each stage of the process were stained using Periodic Acid Schiff and Naphthol Blue-Black. • Key Results The first cellular divisions were localized close to the vascular vessels of the leaf. The primary calli were obtained within 2 months. Fine friable granular calli grew quickly after the primary calli were chopped. Individual embryogenic cells were identified that rapidly started to divide and developed into globular proembryos. In addition, in the microcalli, breaking zones appeared in the thick pectocellulosic walls which delimited the pluricellular proembryos. The anatomy of somatic embryos is similar to that of zygotic embryos despite a deficit in the accumulation of intracellular proteins. When rooted with NAA, the vitroplants developed a strong orthotropic taproot. • Conclusions This study contributes to understanding the whole process of somaticembryogenesis, but two specific questions remain to be answered: what factors are involved in the reactivation of the somatic cells at the beginning of the initial callogenesis, and why do the somatic embryos not accumulate proteins in their tissues during maturation?
SANE, D.; ABERLENC-BERTOSSI, F.; GASSAMA-DIA, Y. K.; SAGNA, M.; TROUSLOT, M. F.; DUVAL, Y.; BORGEL, A.
Many of the regulatory processes occurring during plant embryogenesis are still unknown. Relatively few cells are involved, and they are embedded within maternal tissues, making this developmental phase difficult to study. Somaticembryogenesis is a more accessible system, and many important regulatory genes appear to function similar to zygotic development, making somaticembryogenesis a valuable model for the study of zygotic processes. To better understand the role of the Arabidopsis (Arabidopsis thaliana) MADS factor AGAMOUS-Like15 (AGL15) in the promotion of somaticembryogenesis, direct target genes were identified by chromatin immunoprecipitation-tiling arrays and expression arrays. One potential directly up-regulated target was At5g61590, which encodes a member of the ethylene response factor subfamily B-3 of APETALA2/ETHYLENE RESPONSE FACTOR transcription factors and is related to Medicago truncatula SOMATIC EMBRYO-RELATED FACTOR1 (MtSERF1), which has been shown to be required for somaticembryogenesis in M. truncatula. Here, we report confirmation that At5g61590 is a directly expressed target of AGL15 and that At5g61590 is essential for AGL15’s promotion of somaticembryogenesis. Because At5g61590 is a member of the ETHYLENE RESPONSE FACTOR family, effects of ethylene on somaticembryogenesis were investigated. Precursors to ethylene stimulate somaticembryogenesis, whereas inhibitors of ethylene synthesis or perception reduce somaticembryogenesis. To extend findings to a crop plant, we investigated the effects of ethylene on somaticembryogenesis in soybean (Glycine max). Furthermore, we found that a potential ortholog of AGL15 in soybean (GmAGL15) up-regulates ethylene biosynthesis and response, including direct regulation of soybean orthologs of At5g61590/MtSERF1 named here GmSERF1 and GmSERF2, in concordance with the M. truncatula nomenclature.
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 somaticembryogenesis 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
Plants were successfully regenerated via somaticembryogenesis 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. ...
A method for somaticembryogenesis and fertile green plant regeneration from suspension cell-derived protoplasts of rye ( Secale cereale L. cv. Auvinen) was developed. Fast-growing and friable embryogenic calli with a high regeneration capacity were induced from immature rye inflorescences using modified MS medium. These friable embryogenic calli were used for suspension culture initiation in liquid AA medium. A high
Brassinosteroids, which control plant growth and development, are sensed by the leucine-rich repeat (LRR) domain of the membrane receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1), but it is unknown how steroid binding at the cell surface activates the cytoplasmic kinase domain of the receptor. A family of somaticembryogenesis receptor kinases (SERKs) has been genetically implicated in mediating early brassinosteroid signaling events. We found a direct and steroid-dependent interaction between the BRI1 and SERK1 LRR domains by analysis of their complex crystal structure at 3.3 angstrom resolution. We show that the SERK1 LRR domain is involved in steroid sensing and, through receptor-co-receptor heteromerization, in the activation of the BRI1 signaling pathway. Our work reveals how known missense mutations in BRI1 and in SERKs modulate brassinosteroid signaling and the targeting mechanism of BRI1 receptor antagonists. PMID:23929946
Santiago, Julia; Henzler, Christine; Hothorn, Michael
Summary \\u000a In vitro regeneration of plants via somaticembryogenesis through cell suspension culture was achieved in horsegram. Embryogenic calluses\\u000a were induced on leaf segments on solid Murashige and Skoog (MS) medium with 9.0 ?M 2,4-dichlorophenoxyacetic acid (2,4-D). Differentiation of somatic embryos occurred when the embryogenic calluses were transferred\\u000a to liquid MS medium containing 2,4-D. Maximum frequency (33.2%) of somatic embryos
S. Varisai Mohamed; C. S. Wang; M. Thiruvengadam; N. Jayabalan
The genetic basis of the regeneration process in cultured immature embryos of rye (Secale cereale L.) was analyzed. The experiments were designed to reveal differences between the in vitro culture responses of two inbred lines: L318 (a high regeneration ability) and L9 (a low potential for regeneration). The rye ortologues of plant genes previously recognized as crucial for somaticembryogenesis and morphogenesis in vitro were identified. Using oligonucleotide primers designed to conserved regions of the genes SomaticEmbryogenesis Receptor-like Kinase (SERK), Leafy Cotyledon 1 (LEC1), Viviparous 1 (VP1) and NiR (encoding ferredoxin-nitrite reductase), it was possible to amplify specific homologous sequences from rye RNA by RT-PCR. The transcript levels of these genes were then measured during the in vitro culture of zygotic embryos, and the sites of expression localized. The expression profiles of these genes indicate that their function is likely to be correlated with the in vitro response of rye. In line L9, increased expression of the rye SERK ortologue was observed at most stages during the culture of immature embryos. The suppression of ScSERK expression appears to start after the induction of somaticembryogenesis and lasts up to plant regeneration. The rye ortologues of the LEC1 and VP1 genes may function in a complimentary manner and have a negative effect on the production of the embryogenic callus. The expression of the rye NiR ortologue during in vitro culture reveals its importance in the process of plant regeneration.
Summary. The objective of this paper is to review the relationship between induction of microspore embryogenesis and chromosome doubling.\\u000a It has been augmented with relative data on chromosome doubling by nuclear fusion. Some of the treatments used for induction\\u000a of embryogenesis may also lead to doubling of the chromosome number, either through nuclear fusion or endomitosis. High frequencies\\u000a of spontaneous chromosome
The purpose of the study was to evaluate the possible genetic effect on vegetative propagation of Coffea canephora. Diversity for somaticembryogenesis (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
The aim of this study was to improve the direct somaticembryogenesis and initiate embryogenic callus formation in camphor\\u000a tree (Cinnamomum camphora L.) on hormone-free medium. The influence of osmotic stress pretreatment of immature zygotic embryos (0.5 and 1.0 M solution\\u000a of sucrose for 12, 24, 48, 72, 96, 120, and 144 h at 4 or 25°C) before cultured on hormone-free medium,
Plant cells have the capacity to generate a new plant without egg fertilization by a process known as somaticembryogenesis (SE), in which differentiated somatic cells can form somatic embryos able to generate a functional plant. Although there have been advances in understanding the genetic basis of SE, the epigenetic mechanism that regulates this process is still unknown. Here, we show that the embryogenic development of Coffea canephora proceeds through a crosstalk between DNA methylation and histone modifications during the earliest embryogenic stages of SE. We found that low levels of DNA methylation, histone H3 lysine 9 dimethylation (H3K9me2) and H3K27me3 change according to embryo development. Moreover, the expression of LEAFY COTYLEDON1 (LEC1) and BABY BOOM1 (BBM1) are only observed after SE induction, whereas WUSCHEL-RELATED HOMEOBOX4 (WOX4) decreases its expression during embryo maturation. Using a pharmacological approach, it was found that 5-Azacytidine strongly inhibits the embryogenic response by decreasing both DNA methylation and gene expression of LEC1 and BBM1. Therefore, in order to know whether these genes were epigenetically regulated, we used Chromatin Immunoprecipitation (ChIP) assays. It was found that WOX4 is regulated by the repressive mark H3K9me2, while LEC1 and BBM1 are epigenetically regulated by H3K27me3. We conclude that epigenetic regulation plays an important role during somatic embryogenic development, and a molecular mechanism for SE is proposed.
Nic-Can, Geovanny I.; Lopez-Torres, Adolfo; Barredo-Pool, Felipe; Wrobel, Kazimierz; Loyola-Vargas, Victor M.; Rojas-Herrera, Rafael; De-la-Pena, Clelia
Energy dispersive X-ray fluorescence (ED-XRF) technique has been used for the determination of trace element profile during different developmental stages of somatic embryogenic callus of an economically important medicinal plant, Plantago ovata Forssk. Somaticembryogenesis is a plant tissue culture-based technique, which is used for plant regeneration and crop improvement. In the present investigation, elemental content was analysed using ED-XRF technique during different developmental stages and also determine the effect of additives--casein hydrolysate and coconut water on the trace elemental profile of embryogenic callus tissue of P. ovata. Subsequent experiments showed significant alteration in the concentration of K, Ca, Mn, Fe, Zn, Cu, Br, and Sr in both the embryogenic and non-embryogenic callus. Higher K, Ca, Fe, Cu, and Zn accumulation was in embryogenic tissue stage compared to other stages, suggesting these elements are crucial for successful embryogenesis. The results suggest that this information could be useful for formulating a media for in vitro embryo induction of P. ovata. PMID:19696971
Direct somaticembryogenesis on immature zygotic embryos in vitro has been confirmed for Trifolium pratense and extended to T. resupinatum and T. subterraneum. For all species direct embryo cloning can be achieved on an appropriate basal medium supplemented with 1gl-1 yeast extract and 0.05 mgl-1 BAP. Basal medium\\/sucrose formulation, level of yeast extract and level of BAP affected the nature
Somaticembryogenesis inChamaecyparis pisifera was initiated from immature seeds collected from the end of June to early July. We obtained initiation frequencies ranging\\u000a from 12.5 to 33.3% using whole seed explants in liquid media. Embryogenic cultures were maintained and proliferated for more\\u000a than a year in solid and liquid media. High maturation frequencies of ‘high quality’ embryos were obtained on
Here we report on the isolation and characterization of a somaticembryogenesis receptor-like kinase (OsSERK1) gene in rice (Oryza sativa). The OsSERK1 gene belongs to a small subfamily of receptor-like kinase genes in rice and shares a highly conserved gene structure and extensive sequence homology with previously reported plant SERK genes. Though it has a basal level of expression in
The ontogenetic developmental stages of saffron somaticembryogenesis have been studied and characterized using light microscopy\\u000a and the biochemical determination of the antioxidant enzymatic system. The embryogenic callus underwent internal segmented\\u000a divisions with the formation of globular embryos that were attached to the callus surface by a broad multicellular structure.\\u000a Further development of the embryoids was characterized by the emergence
Silvia Blazquez; Enrique Olmos; José Antonio Hernández; Nieves Fernández-García; José Antonio Fernández; Abel Piqueras
We describe here a simple and efficient system of soybean (Glycine max L. Merrill) regeneration through direct somaticembryogenesis by using immature embryonic shoot tips (IEST) as explants.\\u000a The cultivar Kaohsiung 10 (cv. K10) used in this study did not show embryogenic response either from mature seed-derived explants\\u000a (cotyledon, embryonic tip, leaf, shoot and root) or immature cotyledons. However, it
An efficient in vitro plant regeneration protocol through somaticembryogenesis and direct shoot organogenesis has been developed for pearl millet\\u000a (Pennisetum glaucum). Efficient plant regeneration is a prerequisite for a complete genetic transformation protocol. Shoot tips, immature inflorescences,\\u000a and seeds of two genotypes (843B and 7042-DMR) of pearl millet formed callus when cultured on Murashige and Skoog (MS) medium\\u000a supplemented
Basal media and plant growth regulators were tested for the promotion of somaticembryogenesis 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
Efficient plant regeneration through somaticembryogenesis was achieved from callus cultures derived from semi-mature cotyledon explants of Dalbergia sissoo Roxb., a timber-yielding leguminous tree. Somatic embryos developed over the surface of embryogenic callus and occasionally, directly from cotyledon explants without intervening callus phase. Callus cultures were initiated from cotyledon pieces of D. sissoo on Murashige and Skoog (1962) medium supplemented with 4.52, 9.04, 13.57, and 18.09 mumol/L 2,4-dichlorophenoxyacetic acid and 0.46 mumol/L Kinetin. Maximum percentage response for callus formation was 89% on MS medium supplemented with 9.04 mumol/L 2,4-D' and 0.46 mumol/L Kn. Somaticembryogenesis was achieved after transfer of embryogenic callus clumps to 1/2-MS medium without plant growth regulators (1/2-MSO). Average numbers of somatic embryos per callus clump was 26.5 on 1/2-MSO medium after 15 weeks of culture. Addition of 0.68 mmol/L L-glutamine to 1/2-MSO medium enhanced somaticembryogenesis frequency from 55% to 66% and the number of somatic embryos per callus clump from 26.5 to 31.1. Histological studies were carried out to observe various developmental stages of somatic embryos. About 50% of somatic embryos converted into plantlets on 1/2-MSO medium containing 2% sucrose, after 20 days of culture. Transfer of somatic embryos to 1/29-MSO medium containing 10% sucrose for 15 days prior to transfer on 1/2-MS medium with 2% sucrose enhanced the conversion of somatic embryos into plantlets from 50 to 75%. The plantlets with shoots and roots were transferred to 1/2 and 1/4-liquid MS medium, each for 10 days, and then to plastic pots containing autoclaved peat moss and compost mixture (1:1). 70% of the plantiets survived after 10 weeks of transfer to pots. 120 regenerated plantlets out of 150 were successfully acclimatised. After successful acclimatisation, plants were transferred to earthen pots. PMID:12756922
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 188.8.131.52) is closely linked with the precocious phases of somaticembryogenesis in leaf tissues of an interspecific chicory hybrid (Cichorium intybus L. var. sativa x 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
Somaticembryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results in somaticembryogenesis, the mechanisms underlying the initiation of somatic embryos (SEs) are poorly understood. In this study, we showed that YUCCAs (YUCs) encoding key enzymes in auxin biosynthesis are required for SE induction in Arabidopsis. To identify other factors mediating SE initiation, we performed transcriptional profiling and gene expression analysis. The results showed that genes involved in ethylene biosynthesis and its responses were down-regulated during SE initiation. Ethylene level decreased progressively during SE initiation, whereas treatment with the metabolic precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), or mutation of ETHYLENE-OVERPRODUCTION1 (ETO1) disrupted SE induction, suggesting that ethylene plays a role in this process. Suppression of SE induction was also observed in the constitutive triple response 1 (ctr1) mutant, in which ethylene signaling was enhanced. These results indicate that down-regulation of not only ethylene biosynthesis, but also ethylene response is critical for SE induction. We further showed that ethylene disturbed SE initiation through inhibiting YUC expression that might be involved in local auxin biosynthesis and subsequent auxin distribution. Our results provide new information on the mechanisms of hormone-regulated SE initiation. PMID:23271028
Bai, Bo; Su, Ying Hua; Yuan, Jia; Zhang, Xian Sheng
The frequency of long-term secondary somaticembryogenesis 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
Summary This is the first report of simultaneous organogenesis and somaticembryogenesis in Arnebia euchroma, a highly valued, critically endangered medicinal plant of the Himalaya. Root-derived callus showed only rhizogenesis, whereas\\u000a leaf-derived callus showed simutaneous organogenesis and somaticembryogenesis. Organogenesis was optimal (12.2 shoots per\\u000a culture) in 1 ?M indole-3-butyric acid combined with 2.5 ?M 6-benzyladenine and induction of somaticembryogenesis
Little is known about the genes expressed during grapevine somaticembryogenesis. Both groups of SomaticEmbryogenesis Receptor Kinase (SERK) and Leafy Cotyledon (LEC and L1L) genes seem to play key roles during somaticembryogenesis 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
Paul Schellenbaum; Alban Jacques; Pascale Maillot; Christophe Bertsch; Flore Mazet; Sibylle Farine; Bernard Walter
It was shown earlier, that ginseng embryogenic cell culture 2c3 was obtained as a result of callus cells transformation with the Agrobacterium rhizogenes rolC oncogene. In the present report we determine that inhibitors of Ca2+-channels (LaCl3, verapamil, niflumic acid) certainly lowered the quantity of somatic embryos in the 2c3 cell culture. This is the evidence of the influence of calcium-dependent signal system on plant embryogenesis. Protein kinases inhibitors W7 and H7 also caused the lowering of somatic embryos quantity in the 2c3 cell culture. We analysed changes of CDPK genes expression in embryogenic 2c3 cell culture. Total expression decreased 1.2-1.5 times comparing with the control callus culture. CDPK expression in the 2c3 embryogenic culture lowered by the inhibition of expression of the gene subfamilies PgCDPK1 (PgCDPK1a and PgCDPK1b) and PgCDPK3 (PgCDPK3a). At the same time, expression of PgCDPK2 gene subfamily (PgCDPK2b and PgCDPK2d) was increased. We suppose that genes of PgCDPK2 subfamily might be responsible for the embryogenesis initiation in the 2c3 ginseng cell culture. It was shown for the first time that the rolC gene and the process of embryogenesis could change expression of particular forms of CDPK genes. PMID:18610836
Kiselev, K V; Gorpenchenko, T Iu; Chernoded, G K; Dubrovina, A S; Grishchenko, O V; Bulgakov, V P; Zhuravlev, Iu N
Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somaticembryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100–4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somaticembryogenesis of Musa.
Maldonado-Borges, Josefina Ines; Ku-Cauich, Jose Roberto; Escobedo-GraciaMedrano, Rosa Maria
The Arabidopsis thaliana somaticembryogenesis receptor kinases (SERKs) consist of five members, SERK1 to SERK5, of the leucine-rich repeat receptor-like kinase subfamily II (LRR-RLK II). SERK3 was named BRI1-Associated Receptor Kinase 1 (BAK1) due to its direct interaction with the brassinosteroid (BR) receptor BRI1 in vivo, while SERK4 has also been designated as BAK1-Like 1 (BKK1) for its functionally redundant role with BAK1. Here we provide genetic and biochemical evidence to demonstrate that SERKs are absolutely required for early steps in BR signaling. Overexpression of four of the five SERKs-SERK1, SERK2, SERK3/BAK1, and SERK4/BKK1-suppressed the phenotypes of an intermediate BRI1 mutant, bri1-5. Overexpression of the kinase-dead versions of these four genes in the bri1-5 background, on the other hand, resulted in typical dominant negative phenotypes, resembling those of null BRI1 mutants. We isolated and generated single, double, triple, and quadruple mutants and analyzed their phenotypes in detail. While the quadruple mutant is embryo-lethal, the serk1 bak1 bkk1 triple null mutant exhibits an extreme de-etiolated phenotype similar to a null bri1 mutant. While overexpression of BRI1 can drastically increase hypocotyl growth of wild-type plants, overexpression of BRI1 does not alter hypocotyl growth of the serk1 bak1 bkk1 triple mutant. Biochemical analysis indicated that the phosphorylation level of BRI1 in serk1 bak1 bkk1 is incapable of sensing exogenously applied BR. As a result, the unphosphorylated level of BES1 has lost its sensitivity to the BR treatment in the triple mutant, indicating that the BR signaling pathway has been completely abolished in the triple mutant. These data clearly demonstrate that SERKs are essential to the early events of BR signaling. PMID:22253607
Gou, Xiaoping; Yin, Hongju; He, Kai; Du, Junbo; Yi, Jing; Xu, Shengbao; Lin, Honghui; Clouse, Steven D; Li, Jia
The Arabidopsis thaliana SomaticEmbryogenesis Receptor Kinases (SERKs) consist of five members, SERK1 to SERK5, of the leucine-rich repeat receptor-like kinase subfamily II (LRR-RLK II). SERK3 was named BRI1-Associated Receptor Kinase 1 (BAK1) due to its direct interaction with the brassinosteroid (BR) receptor BRI1 in vivo, while SERK4 has also been designated as BAK1-Like 1 (BKK1) for its functionally redundant role with BAK1. Here we provide genetic and biochemical evidence to demonstrate that SERKs are absolutely required for early steps in BR signaling. Overexpression of four of the five SERKs—SERK1, SERK2, SERK3/BAK1, and SERK4/BKK1—suppressed the phenotypes of an intermediate BRI1 mutant, bri1-5. Overexpression of the kinase-dead versions of these four genes in the bri1-5 background, on the other hand, resulted in typical dominant negative phenotypes, resembling those of null BRI1 mutants. We isolated and generated single, double, triple, and quadruple mutants and analyzed their phenotypes in detail. While the quadruple mutant is embryo-lethal, the serk1 bak1 bkk1 triple null mutant exhibits an extreme de-etiolated phenotype similar to a null bri1 mutant. While overexpression of BRI1 can drastically increase hypocotyl growth of wild-type plants, overexpression of BRI1 does not alter hypocotyl growth of the serk1 bak1 bkk1 triple mutant. Biochemical analysis indicated that the phosphorylation level of BRI1 in serk1 bak1 bkk1 is incapable of sensing exogenously applied BR. As a result, the unphosphorylated level of BES1 has lost its sensitivity to the BR treatment in the triple mutant, indicating that the BR signaling pathway has been completely abolished in the triple mutant. These data clearly demonstrate that SERKs are essential to the early events of BR signaling.
Du, Junbo; Yi, Jing; Xu, Shengbao; Lin, Honghui; Clouse, Steven D.; Li, Jia
Culture temperature determines the developmental fate of isolated microspores from Brassica napus L. At 18°C, tricellular pollen develops, whereas culture at 32°C for 8 h leads to the quantitative and synchronous induction of embryogenesis, and ultimately to the formation of embryos. We investigated the changes in protein synthesis that are associated with this 8-h inductive period by using in-situ [35S]methionine
Jan H. G. Cordewener; Ronald Busink; Jan A. Traas; Jan B. M. Custers; Hans J. M. Dons; Michiel M. Lookeren Campagne
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
Masana Noma; Jochen Huber; Dieter Ernst; Richard P. Pharis
Isolated microspores of flowering plants can undergo embryogenesis when cultured in vitro under appropriate conditions. This process is triggered by various stresses including cold, heat and starvation. We have studied the effects of these stresses on the induction of embryogenesis in wheat microspores isolated from freshly cut or cold pretreated tillers. We show that the stress can be applied directly
Ari Indrianto; Erwin Heberle-Bors; Alisher Touraev
Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant\\u000a originating from a 20-year-old tree of H. r. rhamnoides × mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis\\u000a in leaf explants and in roots of intact seedlings, and induction of direct somatic
An efficient somaticembryogenesis system has been established in Catharanthus roseus (L.) G. Don in which primary and secondary embryogenic calluses were developed from hypocotyls and primary cotyledonary somatic\\u000a embryos (PCSEs), respectively. Two types of calluses were different in morphology and growth behaviour. Hypocotyl-derived\\u000a embryogenic callus (HEC) was friable and fast-growing, while secondary callus derived from PCSE was compact and
Somaticembryogenesis (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
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 somaticembryogenesis 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 somaticembryogenesis. Proper content and localization of hydroxyproline rich glycoproteins seem to be essential for the formation and regeneration of banana somatic embryos.
In this thesis a study of the regulation of coordinated growth and the development of polarity during embryogenesis of carrot, Daucus carota L., is described. To this end, several microscopical techniques were used, such as light microscopy, fluorescence microscopy, confocal scanning laser microscopy and electron microscopy. Next to this, immunocytochemical methods were used frequently to localize proteins in plant tissue
Plants of Coffea arabica L. derived via somaticembryogenesis, namely, somaclones, were evaluated with C. arabica seedlings grown in the nursery. At the time of their transfer to the nursery, somaclones of C. arabica cvs. Caturra and Costa Rica 95 (Catimor) were smaller and less vigorous than seedlings of the same cultivars. Following an\\u000a initial slow growth for a period
Andrea Menéndez-Yuffá; Dominique Barry-Etienne; Benoît Bertrand; Frédéric Georget; Hervé Etienne
A new culture medium, originally designed and shown to grow cell suspensions from a variety of loblolly pine (Pinus taeda L.) explants, was used to study growth and somaticembryogenesis of the wild carrot (Daucus carota L.) in cell suspensions. The new loblolly pine medium (LM) differed from the standard wild carrot medium (WCM) in having very low Ca2+, very
The aim of this study was the improvement of embryo production in wheat anther culture. Three butanol alcohols, n-butanol, sec-butanol and tert-butanol, were evaluated for their effect on microspore embryogenesis in two spring cultivars\\u000a of wheat, Pavon and Caramba. Application of n-butanol, at 0.1 and 0.2% (v\\/v) in the induction media for 5 h, highly improved embryo production in both cultivars.
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
José Luis Cabrera-Ponce; Ariadne Vegas-Garcia; Luis Herrera-Estrella
Exogenously supplied ammonium ion is critical to alfalfa morphogenesis in vitro. In alfalfa, the ability to induce the formation\\u000a of either roots or somatic embryos provided an opportunity to examine the effects of ammonium ion on each pattern of morphogenesis.\\u000a Somatic embryo formation required a minimum of 12.5 mM NH\\u000a 4\\u000a +\\u000a in regeneration medium for optimal expression. Root formation
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
We report here the isolation of the Arabidopsis SOMATICEMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (AtSERK1) gene and we demonstrate its role during establishment of somaticembryogenesis 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 somaticembryogenesis. Thus, an increased AtSERK1 level is sufficient to confer embryogenic competence in culture.
Hecht, Valerie; Vielle-Calzada, Jean-Philippe; Hartog, Marijke V.; Schmidt, Ed D.L.; Boutilier, Kim; Grossniklaus, Ueli; de Vries, Sacco C.
With the aim of understanding the molecular mechanisms underlying somaticembryogenesis (SE) in oil palm, we examined transcriptome changes that occur when embryogenic suspension cells are initiated to develop somatic embryos. Two reciprocal suppression subtractive hybridization (SSH) libraries were constructed from oil palm embryogenic cell suspensions: one in which embryo development was blocked by the presence of the synthetic auxin analogue 2,4-dichlorophenoxyacetic acid (2,4-D: ) in the medium (proliferation library); and another in which cells were stimulated to form embryos by the removal of 2,4-D: from the medium (initiation library). A total of 1867 Expressed Sequence Tags (ESTs) consisting of 1567 potential unigenes were assembled from the two libraries. Functional annotation indicated that 928 of the ESTs correspond to proteins that have either no similarity to sequences in public databases or are of unknown function. Gene Ontology (GO) terms assigned to the two EST populations give clues to the underlying molecular functions, biological processes and cellular components involved in the initiation of embryo development. Macroarrays were used for transcript profiling the ESTs during SE. Hierarchical cluster analysis of differential transcript accumulation revealed 4 distinct profiles containing a total of 192 statistically significant developmentally regulated transcripts. Similarities and differences between the global results obtained with in vitro systems from dicots, monocots and gymnosperms will be discussed. PMID:19199047
Lin, Hsiang-Chun; Morcillo, Fabienne; Dussert, Stéphane; Tranchant-Dubreuil, Christine; Tregear, James W; Tranbarger, Timothy John
The effect of different vitamins and inorganic micronutrients on callus growth and the induction and proliferation of somatic embryos from young mature, fully expanded leaves of chilli pepper (Capsicum annuum L.) was investigated. Explants were cultured on a solid Murashige and Skoog (MS) medium supplemented with 8% (w\\/v) sucrose, 12.9 µM 6-benzyladenine, 9 µM 2,4-dichlorophenoxyacetic acid and 0.5 mg l-1
S. Kintzios; J. B. Drossopoulos; Ch. Lymperopoulos
In vitro cultures of flax (Linum usitatissimum L.) were established on MS medium and four samplings were made during the 7 weeks of culture. The samples varied from the original hypocotyl segments (HS) at t0 and segments with incipient calli formation (HSC) after 2 weeks (t2), to embryogenic calli (EC), non-embryogenic calli (NEC) and somatic embryos (SE) collected after 5
The influence of media components on the initiation of somaticembryogenesis in three genotypes of soybean was investigated. The following genotypes were used: Iroquois, Macon, and Savoy. Media modifications included sucrose concentration, type and concentration of auxin at two pH levels, and pH l...
Embryogenic cell suspension cultures of Coffea arabica cv. Caturra Rojo were treated with salicylic acid (SA). Two concentrations, 10-12 and 10-10 M, had a significant effect on the growth rate of the cell cultures when compared to the control, and this effect was concentration-dependent. These two SA concentrations also had a dramatic effect on both the number of somatic embryos
F. Quiroz-Figueroa; M. Méndez-Zeel; A. Larqué-Saavedra; V. Loyola-Vargas
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
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
The involvement of the plant growth regulator ethylene in somatic embryo maturation of Pinus sylvestris (L.) was investigated. Genes that encoded 1-aminocyclopropane-1-carboxylate synthase (ACS), the rate-limiting enzyme in the\\u000a ethylene biosynthesis pathway, were isolated and characterized. Two novel complementary DNAs (cDNAs) of PsACS1 and PsACS2 that encode ACS were isolated from embryogenic cultures (ECs) along with their polymerase chain reaction
The effect of TDZ was studied on seedlings of pigeonpea. Seedlings raised from decoated seeds on MS basal medium supplemented with a low concentration of TDZ (0.05–1.0 ?M) induced multiple shoots, and an intermediary concentration (5.0 ?M) produced clusters of leafy structures, and a higher concentration (10.0 or 20.0 ?M) completely switched the regeneration pathway by inducing somatic embryos at
N. Dolendro Singh; Lingaraj Sahoo; Neera Bhalla Sarin; Pawan K Jaiwal
Somatic embryos directly formed at cut edges or on the surface of leaf explants, around cut ends or along side surfaces of petiole and stem explants of ‘Golden Pothos’ [ Epipremnum aureum (Linden & Andre) Bunt.] on Murashige and Skoog (MS) medium supplemented with N-(2-chloro-4-pyridyl)- N?-phenylurea (CPPU) or N-phenyl- N?-1, 2, 3-thiadiazol-5-ylurea (TDZ) with ?-naphthalene acetic acid (NAA) and a
Somatic embryos directly formed at cut edges or on the surface of leaf explants, around cut ends or along side surfaces of petiole and stem explants of 'Golden Pothos' [Epipremnum aureum (Linden & Andre) Bunt.] on Murashige and Skoog (MS) medium supplemented with N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) or N-phenyl-N'-1, 2, 3-thiadiazol-5-ylurea (TDZ) with alpha-naphthalene acetic acid (NAA) and a medium called MK containing MS salts with Kao's vitamins, supplemented with 2.0 mg/l TDZ and 0.2 mg/l NAA. Somatic embryos were also produced on MS medium containing 2.0 mg/l kinetin (KN) and 0.5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) from leaf and petiole explants, MS medium supplemented with 2.0 mg/l CPPU and 0.5 mg/l 2,4-D from petiole and stem explants, and 2.0 mg/l TDZ and 0.2 mg/l or 0.5 mg/l 2,4-D from stem explants. In addition, somatic embryos occurred from stem explants on Chu's N6 medium containing 2.0 mg/l CPPU and 0.2 mg/l NAA. Somatic embryos matured and grew into multiple buds, shoots, or even plantlets after 2-3 months on the initial culture medium. Germination was optimal on MS medium containing either 2 mg/l 6-benzylaminopurine (BA) and 0.2 mg/l NAA or 2 mg/l zeatin and 0.2 mg/l NAA. Shoots elongated better and roots developed well on MS medium with no growth regulators. Approximately 30-100 plantlets were regenerated from each explant. The regenerated plants grew vigorously after transplanting to a soil-less container substrate in a shaded greenhouse. PMID:15688236
Background Somaticembryogenesis (SE), by which somatic cells of higher plants can dedifferentiate and reorganize into new plants, is a notable illustration of cell totipotency. However, the precise molecular mechanisms regulating SE remain unclear. To characterize the molecular events of this unique process, transcriptome analysis, in combination with biochemical and histological approaches, were conducted in cotton, a typical plant species in SE. Genome-wide profiling of gene expression allowed the identification of novel molecular markers characteristic of this developmental process. Results RNA-Seq was used to identify 5,076 differentially expressed genes during cotton SE. Expression profile and functional assignments of these genes indicated significant transcriptional complexity during this process, associated with morphological, histological changes and endogenous indole-3-acetic acid (IAA) alteration. Bioinformatics analysis showed that the genes were enriched for basic processes such as metabolic pathways and biosynthesis of secondary metabolites. Unigenes were abundant for the functions of protein binding and hydrolase activity. Transcription factor–encoding genes were found to be differentially regulated during SE. The complex pathways of auxin abundance, transport and response with differentially regulated genes revealed that the auxin-related transcripts belonged to IAA biosynthesis, indole-3-butyric acid (IBA) metabolism, IAA conjugate metabolism, auxin transport, auxin-responsive protein/indoleacetic acid-induced protein (Aux/IAA), auxin response factor (ARF), small auxin-up RNA (SAUR), Aux/IAA degradation, and other auxin-related proteins, which allow an intricate system of auxin utilization to achieve multiple purposes in SE. Quantitative real-time PCR (qRT-PCR) was performed on selected genes with different expression patterns and functional assignments were made to demonstrate the utility of RNA-Seq for gene expression profiles during cotton SE. Conclusion We report here the first comprehensive analysis of transcriptome dynamics that may serve as a gene expression profile blueprint in cotton SE. Our main goal was to adapt the RNA-Seq technology to this notable development process and to analyse the gene expression profile. Complex auxin signalling pathway and transcription regulation were highlighted. Together with biochemical and histological approaches, this study provides comprehensive gene expression data sets for cotton SE that serve as an important platform resource for further functional studies in plant embryogenesis.
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 somaticembryogenesis 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 somaticembryogenesis. 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 somaticembryogenesis in leaf explants from untreated, field-grown plants. Glyphosate was inhibitory to somaticembryogenesis but only at concentrations above 5 milligrams per liter. Fluridone inhibited somaticembryogenesis at all concentrations tested. Inhibition of somaticembryogenesis 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 somaticembryogenesis and reduced the formation of nonembryogenic callus. Application of IAA or gibberellic acid (GA(3); >5 milligrams per liter) was inhibitory to somaticembryogenesis. These results indicate that endogenous ABA is one of the important factors controlling the embryogenic capacity of leaf explants in Napier grass. PMID:16665403
Efficient in vitro propagation of medicinally important endangered plant C. borivilianum has been achieved through somaticembryogenesis. 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 somaticembryogenesis 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
Rizvi, Mohd Zahid; Kukreja, Arun Kumar; Bisht, Narendra Singh
This study examined the role of endogenous abscisic acid (ABA) and jasmonic acid (JA) in indirect somaticembryogenesis 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
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 somaticembryogenesis, plant regeneration and plant recovery were achieved\\u000a from leaf explants of a mature, elite plant of C. arabica cv. Cauvery
V. Rani; K. P. Singh; B. Shiran; S. Nandy; S. Goel; R. M. Devarumath; H. L. Sreenath; S. N. Raina
Plant regeneration from cultured immature inflorescence segments of Eleusine coracana was obtained by direct shoot development and somaticembryogenesis. Direct development of shoots from cultured inflorescence segments occurred on MS medium supplemented with 2,4-D in combination with zeatin. Inflorescences with well developed spikelets differentiated at a low frequency (<5%) from callus cultures initiated on media supplemented with 2,4-D in combination
Two cDNAs isolated from white spruce [Picea glauca (Moench) Voss] somatic embryos, are predicted to encode a basic class IV chitinase and a ß-1,3-glucanase, respectively corresponding to genesPgChi-1 andPgGlu-1. Each represents a multigene family in spruce. Transcripts homologous toPgChi-1 orPgGlu-1 genes were highly abundant in embryogenic tissues and gradually decreased after tissues were placed on abscisic acid-containing maturation medium, with
Summary Development of somatic embryos of soybeanGlycine max (L.) Merr. has been studied using cultivars J103 and McCall and five auxin-sucrose treatment: naphthalene acetic acid at\\u000a 10 mg\\/liter with 1.5% sucrose (N10); 2,4-dichlorophenoxyacetic acid (2,4-D) at 0.25, 0.5 or 1.0 mg\\/liter with 1.5% sucrose\\u000a (D.25, D.5 D1); and 2,4-D at 25 mg\\/liter with 3% sucrose (D25). Cotyledons were excised aseptically from
L. M. Hartweck; P. A. Lazzeri; D. Cui; G. B. Collins; E. G. Williams
Somatic embryo formation was induced from cotyledon explants of Styrian pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) by using a solid MS medium supplemented with 16.11?µM NAA and 4.44?µM BA or 26.85?µM NAA and 13.32?µM BA. The callus proliferation was more efficient on medium supplemented with 26.85?µM NAA and 13.32?µM BA. In contrast, the embryogenic response was higher
To get a broader view on the molecular mechanisms underlying somaticembryogenesis (SE) in cotton (Gossypium hirsutum L.), global analysis of cotton transcriptome dynamics during SE in different sister lines was performed using RNA-Seq. A total of 204?349 unigenes were detected by de novo assembly of the 214?977?462 Illumina reads. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurements were positively correlated with the RNA-Seq results for almost all the tested genes (R(2) ?=?0.841, correlation was significant at the 0.01 level). Different phytohormone (auxin and cytokinin) concentration ratios in medium and the endogenous content changes of these two phytohormones at two stages in different sister lines suggested the roles of auxin and cytokinin during cotton SE. On the basis of global gene regulation of phytohormone-related genes, numerous genes from all the differentially expressed transcripts were involved in auxin and cytokinin biosynthesis and signal transduction pathways. Analyses of differentially expressed genes that were involved in these pathways revealed the substantial changes in gene type and abundance between two sister lines. Isolation, cloning and silencing/overexpressing the genes that revealed remarkable up- or down-expression during cotton SE were important. Furthermore, auxin and cytokinin play a primary role in SE, but potential cross-talk with each other or other factors remains unclear. PMID:23710882
Plant regeneration via somaticembryogenesis was obtained from pea protoplasts. Strong auxins (picloram or 2.4-D) and increased osmolarity of the medium were necessary for embryo induction. Relatively high amounts of embryogenic calli could be obtained in 2 genotypes. After a period on hormone-free medium, a second induction of somatic embryos was possible. Further development of somatic embryos was accomplished on
A protocol has been developed for plant regeneration from protoplast culture of Crocus pallasii subsp. haussknechtii using regenerable embryogenic calli obtained from shoot meristem culture on MS+9.28 microM kinetin+4.52 microM 2,4-D. Protoplasts were isolated directly from embryogenic calli, embedded in Ca-alginate beads and cultured with nurse cells in MS+4.64 microM kinetin+4.52 microM 2,4-D+5.68 microM ascorbic acid+0.3 M mannitol at 20 +/- 2 degrees C in darkness. After appearing ofmicrocalli on the surface of the beads, they were transferred onto 1/2MS+2.32 microM kinetin+2.26 microM 2,4-D+5.68 microM ascorbic acid for growth of embryogenic calli. Somatic embryos matured on MS medium growth regulator free and germinated on 1/2MS+14.45 microM GA3 +4.43 microM BA at 20 +/- 2 degrees C in a 16/8 h light/dark cycle. PMID:19069554
The LEAFY COTYLEDON2 (LEC2) transcription factor with a plant-specific B3 domain plays a central role in zygotic and somaticembryogenesis (SE). LEC2 overexpression induced in planta leads to spontaneous somatic embryo formation, but impairs the embryogenic response of explants cultured in vitro under auxin treatment. The auxin-related functions of LEC2 appear during SE induction, and the aim of the present study was to gain further insights into this phenomenon. To this end, the effect of LEC2 overexpression on the morphogenic responses of Arabidopsis explants cultured in vitro under different auxin treatments was evaluated. The expression profiles of the auxin biosynthesis genes were analysed in embryogenic cultures with respect to LEC2 activity. The results showed that LEC2 overexpression severely modifies the requirement of cultured explants for an exogenous auxin concentration at a level that is effective in SE induction and suggested an increase in the auxin content in 35S::LEC2-GR transgenic explants. The assumption of an LEC2 promoted increase in endogenous auxin in cultured explants was further supported by the expression profiling of the genes involved in auxin biosynthesis. The analysis indicated that YUCCAs and TAA1, working in the IPA-YUC auxin biosynthesis pathway, are associated with SE induction, and that the expression of three YUCCA genes (YUC1, YUC4 and YUC10) is associated with LEC2 activity. The results also suggest that the IAOx-mediated auxin biosynthesis pathway involving ATR1/MYB34 and CYP79B2 does not seem to be involved in SE induction. We conclude that de novo auxin production via the tryptophan-dependent IPA-YUC auxin biosynthesis pathway is implicated in SE induction, and that LEC2 plays a key role in this mechanism. PMID:23722561
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
The influence of light regime, explant position and orientation on direct embryo formation from leaf explants of two Phalaenopsis, P. amabilis and P. Nebula, were investigated to optimize the protocol for regenerating of this orchid. When explants were cultured in light,\\u000a direct embryogenesis was retarded in both species. Embryos showed whitish to pale green in color and larger size than
The influence of media components on the initiation of somaticembryogenesis in three genotypes of soybean was investigated. The following genotypes were used: Iroquois, Macon, and Savoy. Media modifications included sucrose concentration, type and concentration of auxin at two pH levels, and pH level independently. Immature cotyledons were used as the source of explant. Cotyledons were placed on a medium
Nicolle Hofmann; Randall L. Nelson; Schuyler S. Korban
Four-step protocol was established for the in vitro regeneration of Citrus sinensis cv. Tarocco somatic embryos that were morphologically similar to small somatic embryos in vivo. The regeneration procedure\\u000a comprises a mechanical destruction of embryogenic culture to obtain proembryogenic cell masses (PEMs) (step 1) followed by\\u000a culturing on three different media (steps 2–4). The approach developed allows in vitro simulating
N. A. Moiseeva; V. N. Serebryakova; L. Nardi; S. Lucretti; R. G. Butenko
Mature zygotic embryos of Paspalum scrobiculatum L. cv. PSC 1 on MS or N6 nutrient medium supplemented with various concentrations of 2,4-D (4.5 – 22.5 µM) formed embryogenic callus, which differentiated\\u000a into somatic embryos within 5 weeks of culture. The somatic embryos after transfer to hormone-free regeneration medium germinated\\u000a and formed plantlets. Of the two nutrient formulations, N6 was relatively
By manipulating hormone levels, light intensities and temperature, we have developed an efficient leaf-disc method for the regeneration of plants via embryogenesis and for transformation in four genotypes of Vitis vinifera L. In MS basal medium supplemented with 1 mg l-1 6-benzylaminopurine (BAP) and 0.1 mg l-1 2,4-dichlorophenoxyacetic acid, leaf discs cultured for 2 weeks under dark conditions produced calli
D. K. Das; M. K. Reddy; K. C. Upadhyaya; S. K. Sopory
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
Tina Lopes; Ana Capelo; Gina Brito; Joăo Loureiro; Conceiçăo Santos
Cytophotometric analysis of nuclear DNA was carried out in leaves of Coffea arabica L. plants grown in vitro. They were maintained for more than 1 year on MS media containing 0.53 ?M NAA, and 2.32 ?M kinetin, and embryogenic calli and somatic embryos were derived from them. Four suspension cultures of C. arabica differing in their embryogenic potential were also
Svetlana E Zoriniants; Alexander V Nosov; Miriam Monforte-Gonzalez; Marcela Mendes-Zeel; Victor M Loyola-Vargas
Cultured caryopses of finger millet (Eleusine coracana GAERTN) produced callus from shoot apices or mesocotyls depending upon the concentration of picloram and combination of cytokinins in MS basal medium. On subsequent subcultures, numerous somatic embryos differentiated from the callus on MS medium supplemented with picloram and kinetin. The embryos germinated into complete plants on medium devoid of phytohormones. When different
Summary Protoplasts isolated from actively growing cell-suspensions ofAtropa belladonna have been induced to divide repeatedly, and to undergo embryogenesis. An optimal protoplast yield of up to 80% was obtained in 4–5 hours by treating cell-suspensions with an enzyme mixture of cellulase R 10 (1%) and macerozyme R 10 (0.5%) in 0.6 M sorbitol at 30 °C. The protoplasts cultured at
In this work, it was observed a straight relationship between the manipulation of the reduced glutathione (GSH)/glutathione disulfide (GSSG) ratio, nitric oxide emission and quality and number of early somatic embryos in Araucaria angustifolia, a Brazilian endangered native conifer. In low concentrations GSH (0.01 and 0.1mM) is a potential NO scavenger in the culture medium. Furthermore, it can increase the number of early SE formed in cell suspension culture media in a few days. However, the maintenance in this low redox state lead to a loss of early somatic embryos polarization. In gelled culture medium, high levels of GSH (5mM) allows the development of globular embryos presenting a high NO emission on embryo apex, stressing its importance in the differentiation and cell division. Taken together these results indicate that the modification of the embryogenic cultures redox state might be an effective strategy to develop more efficient embryogenic systems in A. angustifolia. PMID:22921001
Vieira, Leila do Nascimento; Santa-Catarina, Claudete; de Freitas Fraga, Hugo Pacheco; Dos Santos, André Luis Wendt; Steinmacher, Douglas André; Schlogl, Paulo Sérgio; Silveira, Vanildo; Steiner, Neusa; Floh, Eny Iochevet Segal; Guerra, Miguel Pedro
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
Summary An in vitro culture procedure was established for repetitive embryogenesis and plant regeneration from seed-derived protocorms of Phalaenopsis amabilis var. formosa Shimadzu (Orchidaceae). Seed-derived protocorms were cultured on modified half-strength Murashige and Skoog (1962) basal medium (1\\/2MS) devoid\\u000a of plant growth regulators. After 45 d, 28.1% of protocorms formed embryos from their posterior regions. 1-Phenyl-3-(1,2,3-thiadiazol-5-yl)-urea\\u000a (TDZ; 0.45, 4.54, and 13.62
The relative biological efficiency of 650-kev neutrons and 250-kvp x ; rays for the induction of somatic mutations in the staminal hair cells of a ; variety of Tradescantia occidentalis is described. Six inflorescences were ; irradiated at various neutron and x-ray doses, and somatic mutations were scored ; in the staminal hairs of the flowers e rging for six
Callus was obtained from hypocotyls of Mesembryanthemum crystallinum seedlings cultured on two types of medium-germination medium (GM) and callus induction medium (CIM). Following subculture on shoot induction medium SIM1, the callus formed on CIM medium regenerated roots or somatic embryos, while that obtained on GM medium was non-regenerative. The activities of CuZn-superoxidase dismutase (SOD) were comparable in all calli, but the activities of FeSOD and MnSOD varied according to the activity of photosystem II and the regenerative potential of the tissues. Catalase (CAT) activity was related to H2O2 concentration and affected by both the culture conditions and the morphogenic potential of the calli. The possible role of CAT, SODs and H2O2 in the regeneration of M. crystallinum from callus is discussed. PMID:15517278
Libik, Marta; Konieczny, Robert; Pater, Beata; Slesak, Ireneusz; Miszalski, Zbigniew
Anthers of Morus indica L., with microspores at the uninucleate stage were cultured; and the influence of temperature and kinetin pretreatment on induction of androgenic calluses was examined. The effects of various pretreatments revealed that 24 h cold pretreatment increased the percentage of cultures inducing callus. First microspore division was observed after 16 to 20 days of culture. Th anthers
\\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,
The dosimetry is described for an investigation of the induction of somatic aberrations in Tradescantia occidentalis by substantially mono-energetic neutrons in the energy range 100 keV to 15 MeV, by 200 keV X-rays and cobalt-60 gamma-radiation. Spectrometry was carried out for both neutrons and X-rays. Neutron fluence was measured by uranium fission chambers. Two types of ionization chamber were employed for dose measurement. One chamber was manufactured of CH-plastic and filled with acetylene and the other of graphite and filled with carbon dioxide. Dosimetry for X- and gamma-radiation was by means of lithium fluoride thermoluminescent dosemeters calibrated against a Victoreen ionization chamber. PMID:1084865
Dennis, J A; Delafield, H J; Peaple, L H; Boot, S J
Summary A population of 1,500 plants of the banana hybrid ‘FHIA-18’ (AAAB), regenerated from somatic embryos, which were multiplied in bioreactors, showed similar characteristics to plants propagated from shoot tip cultures both in the acclimatization stage and in field experiments carried out in Cuba. The plants originating from somatic embryos were similar to the plants obtained from shoot tips with respect
Rafael Gómez Kosky; Luis Antonio Barranco; Borys Chong Pérez; Dion Daniels; Maritza Reyes Vega; Manuel de Feria Silva
Spanish red cedar (Cedrela\\u000a odorata L.) is a tropical timber tree native to the Americas from southern Mexico to northern Argentina. Commercial plantations are\\u000a scarce and, consequently, natural populations are overexploited. Traditional propagation practices for the establishment of\\u000a large-scale plantations have had limited success in this species due to the relative scarcity of seeds, its broad genetic\\u000a diversity and the
Yuri J. Peńa-Ramírez; Israel García-Sheseńa; Ángel Hernández-Espinoza; Alfredo Domínguez-Hernández; Felipe A. Barredo-Pool; José A. González-Rodríguez; Manuel L. Robert
High-frequency somaticembryogenesis and shoot regeneration of broccoli (Brassica oleracea var. italica) were achieved. Cotyledon and hypocotyl explants from four varieties of broccoli were cultured on MS and modified MS media (mMS, supplemented with PG-96 organic components) with different combinations of growth regulator. The effects of genotypes, different explants, growth regulator combinations, organic components and AgNO3 on induction of calli
This study describes the formation of somatic embryos directly on the surface of hypocotyl sections of Daucus carota L. after exposure to 450??M of 2,4-D for 2?h, followed by culturing without 2,4-D for 2 weeks. A search for differentially expressed genes immediately\\u000a after the 2,4-D treatment resulted in the identification of two genes, Dchsp-1 and Dcarg-1. Dchsp-1 has homology to
A simple protocol is described for high frequency plant regeneration from protoplasts isolated from leaf-derived embryogenic calli of grapevine (Vitis vinifera L. cv. Koshusanjaku). The protoplasts successfully divided to form somatic embryos by culturing in gellan gum disc-method in which protoplasts were embedded in 2 g\\/l gellan gum-solidified Nitsch's medium containing 2.0 mg\\/l NAA, 0.5 mg\\/l BA, 0.09 M sucrose
Yan-Ming Zhu; Yoichiro Hoshino; Masaru Nakano; Eikichi Takahashi; Masahiro Mii
Summary This research was designed to: a) characterize the normal pH changes that occur when cotton cell are grown in culture; b)\\u000a determine if cotton cells can regulate the pH of their extracellular medium; and c) explore the effects of starting pH on\\u000a cellular differentiation in culture, including formation of somatic embryos. When an aliquot of cotton cell suspension culture\\u000a (Gossypium
Xiao Min Shang; Ji Ying Huang; Candace H. Haigler; Norma L. Trolinder
Leaf and petiole explants of Epipremnum aureum 'Marble Queen' were cultured on Murashige and Skoog basal medium containing three concentrations of either N-(2- chloro-4-pyridl)-N'-phenylurea (CPPU) or N-phenyl-N'-1, 2, 3-thiadiazol-5-ylurea (TDZ) with 1.07 lM a-naphthalene acetic acid (NAA). Somatic embryos appeared directly from explants after 4-6 weeks of culture. TDZ at 4.54 l Mw ith 1.07 lM NAA induced 75% of
Jietang ZhaoQian ZhangJiahua; J. HennyJianjun Chen
Summary Somatic embryos of sweet potato have potential as synthetic seeds. The effects of abscisic acid (ABA) (0,0,0.1, 1.0, 10.0\\u000a and 50.0 ?M) were examined to improve synchrony and proliferation of somatic embryos. Transferring embryos compared to those cultures\\u000a transferred at day 0. The development of embryos in suspension culture supplemented with ABA was poor. However, when calli\\u000a proliferation cultures were
Antonio C. Torres; Nicolas Mfe'e Ze; Daniel J. Cantliffe
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
Javed A. Qureshi; Kutty K. Kartha; Suzanne R. Abrams; Lee Steinhauer
The cell line designated PIR-2 is a nonimmunogenic X-ray-induced thymoma of C57BL/6 origin that is unable to induce antitumor immunity in syngeneic lymphocytes in vitro and in mice in vivo. Fusion of PIR-2 with an allogeneic universal fuser A9HT (clone 3c) resulted in the establishment of a somatic cell hybrid designated A9/PIR. C57BL/6 lymphocytes sensitized in vitro with A9/PIR could lyse parental PIR-2 cells, as well as other syngeneic tumors. However, immunization of mice with the hybrid significantly enhanced PIR-2 tumor takes while it partially protected the animals against a challenge with unrelated syngeneic tumors. The results imply that somatic cell hybridization can increase the immunogenicity of an otherwise nonimmunogenic tumor. However, in view of the enhancing effects of hybrid preimmunization on parental tumor cell growth, the possible application of this approach for immunotherapy is questionable.
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
Any class II type active transposons have not been discovered in rice though transposon (mobile element) is very useful for gene isolation in several plant species. In order to capture somatic instability induced by an endogenous active transposon in rice, stable yellow leaf plants derived from a variegated yellow leaf (yl-v) mutant found in F2 of a cross between distantly related rice varieties were irradiated with carbon and helium ion beams. In M1 plants derived from the seeds irradiated with 50 Gy of 220 MeV carbon ions, a variegated yl plant was generated and this plant showed small or large sectors in leaves expanded later. Most of panicle-row M2 lines segregated into variegated and stable yl plants. In total, the ratio of variegated to stable yl plants was 3:1, suggesting that clear variegation observed on M1 plants might be caused by activation of a cryptic inactive autonomous element by carbon ion beam irradiation.
\\u000a Maritime pine (Pinus pinaster) has originated from the central and western coasts of the Mediterranean. It is well adapted to sandy soil in temperate climates.\\u000a Small natural forests of maritime pine can still be found in many African and European countries. In France, Pinus pinaster covers 1.4 million hectares and out of which 950000 hectares are located in the southwest
\\u000a Black spruce (Picea mariana (Miller)) is one of seven spruce species native to North America. Its natural distribution extends from Labrador to Alaska\\u000a and southward to New York, Minnesota, and Montana. The wood of Picea\\u000a mariana is of great economic importance because of its wide use in the manufacture of paper pulp. It forms a considerable part of\\u000a the pulpwood
Embryogenic callus cultures of ginger were induced from young leaf segments taken from in vitro shoot cultures. Among the four auxins tested in Murashige & Skoog medium, dicamba at 2.7 µM was most effective in inducing and maintaining embryogenic cultures. Efficient plant regeneration was achieved when embryogenic cultures were transferred to Murashige & Skoog medium containing 8.9 µM benzyladenine. Histological
A. Kackar; S. R. Bhat; K. P. S. Chandel; S. K. Malik
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.: sendai 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
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. Postmortem histopathological examination of a donor's brain, combined with premortem clinical criteria, is often the most robust approach to correctly classify an individual as a disease-specific case or unaffected control. In this study, we describe iPSCs generated from a skin biopsy collected postmortem during the rapid autopsy of a 75-year-old male, whole body donor, defined as an unaffected neurological control by both clinical and histopathological criteria. These iPSCs were established in a feeder-free system by lentiviral transduction of the Yamanaka factors, Oct3/4, Sox2, Klf4, and c-Myc. Selected iPSC clones expressed both nuclear and surface antigens recognized as pluripotency markers of human embryonic stem cells (hESCs) and were able to differentiate in vitro into neurons and glia. Statistical analysis also demonstrated that fibroblast proliferation was significantly affected by biopsy site, but not donor age (within an elderly cohort). These results provide evidence that autopsy donor-derived fibroblasts can be successfully reprogrammed into iPSCs, and may provide an advantageous approach for generating iPSC-based neurological disease models.
Hjelm, Brooke E.; Rosenberg, Jon B.; Szelinger, Szabolcs; Sue, Lucia I.; Beach, Thomas G.; Huentelman, Matthew J.; Craig, David W.
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.: sendaď 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.
Zinc-finger nucleases are chimeric proteins consisting of engineered zinc-finger DNA-binding motifs attached to an endonuclease domain. These proteins can induce site-specific DNA double-strand breaks in genomic DNA, which are then substrates for cellular repair mechanisms. Here, we demonstrate that engineered zinc-finger nucleases function effectively in somatic cells of the nematode Caenorhabditis elegans. Although gene-conversion events were indistinguishable from uncut DNA in our assay, nonhomologous end joining resulted in mutations at the target site. A synthetic target on an extrachromosomal array was targeted with a previously characterized nuclease, and an endogenous genomic sequence was targeted with a pair of specifically designed nucleases. In both cases, ?20% of the target sites were mutated after induction of the corresponding nucleases. Alterations in the extrachromosomal targets were largely products of end-filling and blunt ligation. By contrast, alterations in the chromosomal target were mostly deletions. We interpret these differences to reflect the abundance of homologous templates present in the extrachromosomal arrays versus the paucity of such templates for repair of chromosomal breaks. In addition, we find evidence for the involvement of error-prone DNA synthesis in both homologous and nonhomologous pathways of repair. DNA ligase IV is required for efficient end joining, particularly of blunt ends. In its absence, a secondary end-joining pathway relies more heavily on microhomologies in producing deletions.
Morton, Jason; Davis, M. Wayne; Jorgensen, Erik M.; Carroll, Dana
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 mutations, all of which may be induced by the same treatment of the mutagen given to seeds. This is made possible because gene Y(11) for chlorophyll development in the variety L65-1237 is incompletely dominant over its allele y(11), so that twin or double spots composed of a dark green (Y(11)Y(11)) and a yellow (y(11)y(11)) component can be observed adjacent to and as mirror images of each other on the light green Y(11)y(11) leaves in the areas of complementary exchange for these genes. Lack of growth of either component of this double spot as well as several types of chromosomal disturbances give rise to single spots resembling phenotypes of y(11)y(11) or Y(11)Y(11) leaves. Point mutations can be studied by looking for green sectors originating from Y(11)y(11) genotype on the y(11)y(11) plants. Seeds obtained from heterozygous plants were treated with caffeine, cytosine arabinoside, actinomycin D and 5-fluoro-deoxyuridine, all known inhibitors of DNA synthesis, and puromycin, an inhibitor of synthesis of proteins. The treatments with caffeine and actinomycin D increased the frequency of somatic crossing over as measured by the frequency of double spots on Y(11)y(11) leaves, but cytosine arabinoside, 5-fluorodeoxyuridine and puromycin did not. Thus somatic crossing over was induced only by those chemicals which are known to allow rejoining of chromosomes, thereby suggesting a correlation between the two phenomena. These observations indicate that it is not the mere inhibition of DNA synthesis, but some rather more specific event in DNA repair which is responsible for complementary exchanges. Some of these results differ from studies carried out with fungi. The main effect of all chemicals tested, except caffeine and actinomycin D, was inferred to be the production of deletions in Y(11)y(11) plants which raised the frequency of single (dark green or yellow) spots relative to the doubles. Caffeine was the only chemical which constantly increased the frequency of specific point mutations. In the control material, the great majority of spots are found on the upper surface of the leaf. This picture could not be changed in any of the treated materials, thus indicating uniform resistance of spongy mesophyll tissue to the mutagens applied. PMID:17248598
Hyophorbe lagenicaulis is a critically endangered palm of Mauritius. Zygotic embryos were isolated from seeds and germinated in vitro on MS salts and vitamins containing activated charcoal. When seedlings were pre-treated in vitro for 2 weeks in liquid medium containing 0.05 mg l-1 paclobutrazol, 80% survived the transfer to soil. Three-week-old seedlings were sectioned longitudinally and partially embedded in medium
Availability of explants with adequate embryogenic competence is one of the most important limitations for the development\\u000a of regenerable cell suspensions in banana. To increase the number and ease of accessibility to potentially embryogenic explants,\\u000a a novel methodology is described by which young male flower clusters isolated from adult plants are induced to form new flower\\u000a buds and proliferate in
Juan Bernardo Pérez-Hernández; Purificación Rosell-García
Biochemical marker is one of the important tools for the early identification and selection of somaticembryogenesis in plants.\\u000a Studies in developing the biochemical marker for somaticembryogenesis ofEurycoma longifolia disclosed that the regenerated and non-regenerated cotyledons as well as embryogenic and non-embryogenic callus were significantly\\u000a different in terms of the total protein content as well as the specific activity
Sobri Hussein; Rusli Ibrahim; Anna Ling Pick Kiong
IgM+IgD+CD27+ B cells from peripheral blood have been described as circulating marginal zone B cells. It is still unknown when and where these cells develop. These IgM+IgD+CD27+ B cells exhibit somatic hypermutations (SHMs) in their B cell receptors, but the exact nature of the signals leading to induction of these SHMs remains elusive. Here, we show that IgM+IgD+CD27+ B cells carrying SHMs are observed during human fetal development. To examine the role of T cells in human IgM+IgD+CD27+ B cell development we used an in vivo model in which Rag2?/??C?/? mice were repopulated with human hematopoietic stem cells. Using Rag2?/??C?/? mice on a Nude background, we demonstrated that development and induction of SHMs of human IgM+IgD+CD27+ B cells can occur in a T cell–independent manner.
Somaticembryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic seedling production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic seedling production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somaticembryogenesis for mass clonal propagation of the tree. PMID:15789206
Somatic hybridization between triploid and diploid bananas was attempted by using protoplast electrofusion and nurse culture\\u000a techniques. Protoplasts from embryogenic cell suspensions of 'Maçă' (Musa sp. AAB group) were fused with protoplasts from nonembryogenic calli of`Lidi' (Musa sp. AA group). Direct somaticembryogenesis was observed when the fusion-treated protoplasts were cultured with rice nurse\\u000a cells (Oryza sativa L. A-58 line).
Kazumitsu Matsumoto; Alberto Duarte Vilarinhos; Seibi Oka
Somaticembryogenesis is well established for the economic relevant ornamental crop Cyclamen and thus could supplement the elaborate propagation via seeds. However, the use of somaticembryogenesis for commercial large\\u000a scale propagation is still limited due to physiological disorders and asynchronous development within emerged embryos. To\\u000a overcome these problems, profound knowledge of the physiological processes in Cyclamen embryogenesis is essential.
Christina Rode; Sébastien Gallien; Dimitri Heintz; Alain Van Dorsselaer; Hans-Peter Braun; Traud Winkelmann
Embryogenic tissue was induced from developing immature zygotic embryos in Bunge’s pine (Pinus bungeana Zucc. ex Endl.). Induction rate reached 84.4% with our best treatment. Zygotic embryos were dissected from megagametophytes\\u000a and inoculated on different induction media, DCR1 (Gupta PK, Durzan DJ (1985) Plant Cell Rep 4:177–179), BM1 (Gupta PK, Pullman G (1991) U.S. Patent No. 5,036,00) and MSG (Becwar
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.
Edelman, Lucas B.; Chandrasekaran, Sriram; Price, Nathan D.
Somatic embryos and embryogenic callus were initiated from immature zygotic embryos of ginseng (Panax ginseng C.A. Meyer). These somatic embryos were multiplied by adventitious (secondary and tertiary) embryogenesis and their growth and development were dependent on growth hormones in the medium. Auxins, 2,4-d, NAA, and IAA at 1.0 mg l-1 were effective in inducing secondary and tertiary somatic embryos, which
IgM(+)IgD(+)CD27(+) B cells from peripheral blood have been described as circulating marginal zone B cells. It is still unknown when and where these cells develop. These IgM(+)IgD(+)CD27(+) B cells exhibit somatic hypermutations (SHMs) in their B cell receptors, but the exact nature of the signals leading to induction of these SHMs remains elusive. Here, we show that IgM(+)IgD(+)CD27(+) B cells carrying SHMs are observed during human fetal development. To examine the role of T cells in human IgM(+)IgD(+)CD27(+) B cell development we used an in vivo model in which Rag2(-/-)gamma(C)(-/-) mice were repopulated with human hematopoietic stem cells. Using Rag2(-/-)gamma(C)(-/-) mice on a Nude background, we demonstrated that development and induction of SHMs of human IgM(+)IgD(+)CD27(+) B cells can occur in a T cell-independent manner. PMID:18695003
Stress is an essential component during embryogenesisinduction in microspore culture. Cold pretreatment has been used in cereal microspore culture but very seldom attempted in Brassica microspore culture. The effect of cold pretreatment of flower buds subjected to a liquid medium on microspore embryogenesis was investigated in spring and winter Brassica napus, as well as in B. rapa and B.
The described protocol for repetitive somaticembryogenesis (SE) in Eucalyptus globulus produced more somatic embryos than the primary SE protocol. Primary somatic embryos (induced on MS3NAA) were transferred to the same medium, leading to new cycles of somatic embryos, for at least 2 years. The influence of medium\\u000a (MS and B5), plant growth regulators (auxins and cytokinins), and light on secondary
Embryogenesis in plants is not restricted to the fertilized egg cell but can be naturally or\\u000a artificially induced in many different cell types, including somatic cells. Although genetic components\\u000a clearly determine the potential of species\\/genotypes to form somatic embryos, the expression of embryogenic\\u000a competence at the cellular level is defined by developmental and physiological cues. Competent cells\\u000a can respond to
American chestnut (Castanea dentata (Marsh.) Borkh.) plants were regenerated from developing ovules through somaticembryogenesis.\\u000a On an initiation medium containing 18.18 ?M 2,4-dichlorophenoxyacetic acid and 1.11 ?M 6-benzyladenine (BA), 25 out of 1,576\\u000a ovules were induced to form proembryogenic masses (PEMs). These PEMs were cultivated on a development medium for 4 weeks.\\u000a Individual somatic embryos were then grown on a
Zizhuo Xing; William A. Powell; Charles A. Maynard
Flow cytometry was used to measure the nuclear DNA content of Eucalyptus globulus Labill. somatic and zygotic embryos and leaves in order to determine if somaticembryogenesis induces DNA content and ploidy changes in this species. Mature zygotic embryos derived from open-pollination orchard families were collected from a location in the centre of Portugal. One group was kept for nuclear
Elaeocarpus robustus L. (Indian olive, Fam. Elaeocarpaceae) is a well-known evergreen fruit tree and 25 m tall. It is native to Bangladesh and India. The tree is of great economic importance for its fruits and timber. The importance of fleshy sour fruits having citric acid occupy an important position in tropical countries since they provide needed vitamin-C in diets. Its
Immature embryos of Quercus acutissima were collected weekly beginning 5 weeks post-fertilization and cultured on modified MS(Murashige and Skoog) medium containing 1,000 mg\\/l glutamine and 5 mM proline with different combinations of IBA(0.5–10.0 mg\\/l) and BA(0 or 1.0 mg\\/l) in light. The highest percentage of embryogenic cultures occurred on the medium containing 0.5 mg\\/l IBA or 1.0 mg\\/l BA and
Jatropha curcas L. is one potential source of non-edible biofuel-producing energy crop. Its importance also lies in its medicinal properties.\\u000a The species is primarily propagated through heterozygous seeds, and thus the seed oil content varies from 4 to 40%. Moreover,\\u000a due to its perennial nature, seed setting requires 2 to 3 years time. The seed viability and rate of germination are
Timir baran Jha; Priyanka Mukherjee; Mukul Manjari Datta
Leaf explants of Nerium oleander L. produced masses of callus when both an auxin and a cytokinin were included in the medium. Leaves cultured on the B5 medium of Gamborg et al. supplemented with 2,4-dichlorophenoxyacetic acid (2,4-d; 9.05 µM) plus benzyladenine (BA; 4.4 µM) produced callus and profuse rhizogenesis was observed from callus developed from older leaves. On Murashige &
... the biochemical basis of hormonal regulation of the developmental process. This knowledge should lead to the planning of media and various treatments that allow ... This article was written and prepared by U.S. Government employees on ...
A b s t r a c t Bananas and plantains are one of the major fruit crops and a staple food in the developing world. Most of the edible bananas are triploid, highly sterile and hence integration of in vitro techniques banana improvement becomes crucial. In this milieu, technique of somaticembryogenesis in combination with genetic manipulation, has become
Meenakshi Sidha; P. Suprasanna; V. A. Bapat; U. G. Kulkarni; B. N. Shinde
Elevation of the culture temperature to 32°C for approximately 8 h can irreversibly change the developmental fate of isolatedBrassica napus microspores from pollen development to embryogenesis. This stress treatment was accompanied by de-novo synthesis of a number of heat-shock proteins (HSPs) of the 70-kDa class: HSP68 and HSP70. A detailed biochemical and cytological analysis was performed of the HSP68 and
Jan H. G. Cordewener; Gerd Hause; Elke Görgen; Ronald Busink; Bettina Hause; Hans J. M. Dons; André A. M. Van Lammeren; Michiel M. Van Lookeren Campagne; Paul Pechan
Triploid hybrid Citrus plants were regenerated by somaticembryogenesis in vitro from endosperm derived calli. A sequence of media formulations was used to induce and support proliferation of primary callus from endosperm, to induce embryogenesis from primary callus, and to allow embryo development leading to viable plantlets. Calli were induced from cellular endosperm of Citrus sinensis (sweet orange), C. Xparadisi
Background Microspore embryogenesis represents a unique system of single cell reprogramming in plants wherein a highly specialized cell, the microspore, by specific stress treatment, switches its fate towards an embryogenesis pathway. In Brassica napus, a model species for this phenomenon, incubation of isolated microspores at 32°C is considered to be a pre-requisite for embryogenesisinduction. Results We have developed a new in vitro system at lower temperature (18°C) to efficiently induce microspore embryogenesis throughout two different developmental pathways: one involving the formation of suspensor-like structures (52.4%) and another producing multicellular embryos without suspensor (13.1%); additionally, a small proportion of non-responsive microspores followed a gametophytic-like development (34.4%) leading to mature pollen. The suspensor-like pathway followed at 18°C involved the establishment of asymmetric identities from the first microspore division and an early polarity leading to different cell fates, suspensor and embryo development, which were formed by cells with different organizations and endogenous auxin distribution, similar to zygotic embryogenesis. In addition, a new strategy for germination of microspore derived embryos was developed for achieving more than 90% conversion of embryos to plantlets, with a predominance of spontaneous doubled haploids plants. Conclusion The present work reveals a novel mechanism for efficient microspore embryogenesisinduction in B. napus using continuous low temperature treatment. Results indicated that low temperature applied for longer periods favours an embryogenesis pathway whose first division originates asymmetric cell identities, early polarity establishment and the formation of suspensor-like structures, mimicking zygotic embryogenesis. This new in vitro system provides a convenient tool to analyze in situ the mechanisms underlying different developmental pathways during the microspore reprogramming, breaking or not the cellular symmetry, the establishment of polarity and the developmental embryo patterning, which further produce mature embryos and plants.
This essay addresses somatic development during sexual reproduction of ciliated protozoa, which is interpreted as an embryological phenomenon resembling embryogenesis of multicellular organisms. The uniqueness of this somatic development, as distinct from asexual development, resides in its dependence on new information associated with the germ nucleus, and on its involvement of both maternal and postzygotic informational inputs. This understanding derives
A protocol for preserving grape embryogenic cultures indefinitely has been defined, and through recurrent cycles of secondary embryogenesis, Vitis rupestris Scheele cultures are still regenerating after 10 years. The morphogenic competence of a sample of 1,204 somatic embryos with such a long history has been evaluated. Within a 15-month-long culture, secondary embryogenesis regeneration reached an average efficiency of 23%, proving
L. Martinelli; E. Candioli; D. Costa; V. Poletti; N. Rascio
With few exceptions, most cells in adult organisms have lost the expression of stem cell-associated proteins and are instead characterized by tissue-specific gene expression and function. This cell fate specification is dictated spatially and temporally during embryogenesis. It has become increasingly apparent that the elegant and complicated process of cell specification is "undone" in cancer. This may be because cancer cells respond to their microenvironment and mutations by acquiring a more permissive, plastic epigenome, or because cancer cells arise from mutated stem cells. Regardless, these advanced cancer cells must use stem cell-associated proteins to sustain their phenotype. One such protein is Nodal, an embryonic morphogen belonging to the transforming growth factor-? (TGF-?) superfamily. First described in early developmental models, Nodal orchestrates embryogenesis by regulating a myriad of processes, including mesendoderm induction, left-right asymmetry and embryo implantation. Nodal is relatively restricted to embryonic and reproductive cell types and is thus absent from most normal adult tissues. However, recent studies focusing on a variety of malignancies have demonstrated that Nodal expression re-emerges during cancer progression. Moreover, in almost every cancer studied thus far, the acquisition of Nodal expression is associated with increased tumourigenesis, invasion and metastasis. As the list of cancers that express Nodal grows, it is essential that the scientific and medical communities fully understand how this morphogen is regulated in both normal and neoplastic conditions. Herein, we review the literature relating to normal and pathological Nodal signalling. In particular, we emphasize the role that this secreted protein plays during morphogenic events and how it signals to support stem cell maintenance and tumour progression. PMID:23291354
Quail, Daniela F; Siegers, Gabrielle M; Jewer, Michael; Postovit, Lynne-Marie
Oil palm (Elaeis guineensis Jacq.) somatic embryos differ from zygotic embryos in that they accumulate only small amounts of storage proteins. We compared the balance between deposition and degradation of storage proteins during zygotic or somaticembryogenesis and germinative growth in the two types of embryos. During mid to late zygotic embryogenesis, storage proteins accumulated and globulin 7S (GLO7A) gene transcripts were detected, whereas neither protease activity nor cysteine proteinase (CPR) gene transcripts were detected. Globulin degradation occurred after 8 days of in vitro germination in zygotic embryos and was accompanied by a decrease in GLO7A transcripts. Transcripts of three cysteine proteinase genes of the papain family were detected as early as Day 2 of in vitro germination. Several proteolytically active protein bands were identified by zymography, and CPR-like proteins were detected with an antibody raised against the Vicia sativa L. cysteine proteinase CPR1. Protease activities and CPR-like proteins were observed from Day 8 onward when globulin degradation occurred. During somaticembryogenesis and subsequent germinative growth, only small amounts of storage proteins accumulated, even though GLO7A transcripts were detected. Two of the three cysteine proteinase genes were expressed throughout both somaticembryogenesis and germinative growth. Protease activities and CPR-like protein species were detected in somatic embryos at several developmental stages. In contrast to zygotic embryogenesis, the accumulation of globulins and their subsequent mobilization appear to be concomitant processes during somaticembryogenesis, which could explain the low accumulation of storage proteins in somatic embryos. PMID:18519247
Aberlenc-Bertossi, Frédérique; Chabrillange, Nathalie; Duval, Yves; Tregear, James
At a nonpermissive temperature, somatic embryos of the temperature-sensitive (ts) carrot cell mutant ts11 only proceed beyond the globular embryo stage in the presence of medium conditioned by wild-type embryos. The causative component in the conditioned medium has previously been identified as a 32-kD acidic endochitinase. In search of a function for this enzyme in plant embryogenesis, several compounds that
Jong de A. J; Renze Heidstra; Herman P. Spaink; Marijke V. Hartog; Ellen A. Meijer; Theo Hendriks; Fiorella Lo Schiavo; M. Terzi; T. Bisseling; Kammen van A; Vries de S. C
Since the first report of induced pluripotent stem cells (iPSCs) using somatic cell nuclear transfer (SCNT), much focus has been placed on iPSCs due to their great therapeutic potential for diseases such as abnormal development, degenerative disorders, and even cancers. Subsequently, Takahashi and Yamanaka took a novel approach by using four defined transcription factors to generate iPSCs in mice and human fibroblast cells. Scientists have since been trying to refine or develop better approaches to reprogramming, either by using different combinations of transcription factors or delivery methods. However, recent reports showed that the microRNA expression pattern plays a crucial role in somatic cell reprogramming and ectopic introduction of embryonic stem cell-specific microRNAs revert cells back to an ESC-like state, although, the exact mechanism underlying this effect remains unclear. This review describes recent work that has focused on microRNA-mediated approaches to somatic cell reprogramming as well as some of the pros and cons to these approaches and a possible mechanism of action. Based on the pivotal role of microRNAs in embryogenesis and somatic cell reprogramming, studies in this area must continue in order to gain a better understanding of the role of microRNAs in stem cells regulation and activity. PMID:22961769
337 Chromatin diminution is programmed elimination of a part of the genome from presumptive somatic cells during early embryogenesis of some animal species. Chromatin diminution was described for a fairly small number of species of different groups of animals, such as ascarides, myxines, dipterans, Cyclops , and protozoans [2, 3, 6, 8, 10, 13, 14]. Although a great variety of
M. V. Zagoskin; A. K. Grishanin; A. L. Korolev; M. V. Palenko; D. V. Mukha
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 somaticembryogenesis. Red and green light were not different from dark treatments which produced the highest total number of embryoids. After extended time in culture, carrot
The full advantages of somaticembryogenesis as a regeneration system and essential model for performing functional genomics studies and understanding molecular aspect of the ontogenesis of higher plants are demonstrated only in high-frequency, synchronous embryogenic system in liquid culture. In t...
The coat and eye colour mutant beige (bg) leads to the production of distinctive retinal melanocytes with abnormally large pigment granules. Heterozygotes for bg were given 2 Gy acute X-irradiation at various times between day 11.5 of fetal life and 3 days after birth, at which age whole mounts were prepared of the retinal pigmented epithelium (RPE). These were scanned for the presence of mutant retinal melanocytes with large granules, either as single cells or as clones. The earlier the fetal irradiation, the greater was the effect on RPE area at 3 days post-partum (p.p.), which fell to about half normal with the 11.5-day fetal exposures. However, the ultimate size of the retinal melanocytes seemed little affected by the irradiation, although their normal size increased approximately 3-fold between 12.5 days post-coitum (p.c.) and 3 days p.p. Mean numbers of mutant melanocytes per eye were markedly higher than in +/bg controls at all irradiation ages other than 3 days p.p.; when allowance was made for final sizes of irradiated RPE's mutation frequencies fell steadily from 30.0 x 10(-5) at 11.5 days p.c. to 1.0 x 10(-5) at 3 days p.p., with 0.8 x 10(-5) in +/bg and 0.1 x 10(-5) in +/+ controls. The doubling dose of 0.18 Gy at 16.5 days p.c. was similar to that found at 17.5 days p.c. in a previous somatic mutation experiment in which follicular melanocytes were scanned for mutations at different (d and ln) loci.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3333270
This study provides a physiological analysis of somaticembryogenesis 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
Here, we investigate to what extent and under which circumstances cells with dendritic resonance may be misclassified as nonresonant by somatic measurement of resonance properties. We use simple conductance-based multicompartmental models to analyze the effect of dendritic resonance on somatic input (and hence resonance estimates based on somatic recordings). We find that indeed, even a strong dendritic resonance may not
Biological results, including statistical features, are described for the irradiation of Tradescantia occidentalis with 250 kVp X-rays, cobalt-60 gamma-radiation and monoenergetic neutrons with energies between 0-08 and 15 MeV. The effect studied was that of the induction of pink sectors in the otherwise blue staminal hairs of the flowers at low doses of radiation. Statistical aspects of the results suggest that a fraction of the asynchronous cell population in the hairs is very sensitive to neutron radiation, but not necessarily to lower LET radiations. All the results were fitted by a least-squares method by polynomials of different degrees. Best fits to X- and gamma-ray data were provided by second-degree polynomials, and to the neutron data by either second- or third-degree polynomials. Limiting r.b.e. and o.e.r. values at low doses are derived. Some computed microdosimetric parameters are presented in comparison with the r.b.e. values. It is concluded that the effect studied is complex and may not provide a critical test of bio-physical theories of radiation effects. PMID:1084866
The article introduces a series of papers that were originally presented at a workshop titled Genetic Regulatory Network in Embryogenesis and Evaluation. Contents include the following: evolution of cleavage programs in relationship to axial specification...
The plant-specific “no apical meristem” genes are transcription factors that play diverse roles in plant development and stress\\u000a responses. However, whether the gene family is also involved in somaticembryogenesis remains unknown, and no NAC family genes\\u000a have been identified from orchid species. Here, we cloned and characterized a new member of NAC family from somatic embryos\\u000a of Dendrobium candidum.
Polar auxin transport provides a developmental signal for cell fate specification during somaticembryogenesis. Some members of the HD-ZIP III transcription factors participate in regulation of auxin transport, but little is known about this regulation in somaticembryogenesis. 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 somaticembryogenesis 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 somaticembryogenesis. PMID:23566830
Isolated microspores of Brassica napus are developmentally programmed to form gametes; however, microspores can be reprogrammed through stress treatments to undergo appropriate divisions and form embryos. We are interested in the identification and isolation of factors and genes associated with the induction and establishment of embryogenesis in isolated microspores. Standard and normalized cDNA libraries, as well as subtractive cDNA libraries, were constructed from freshly isolated microspores (0 h) and microspores cultured for 3, 5, or 7 d under embryogenesis-inducing conditions. Library comparison tools were used to identify shifts in metabolism across this time course. Detailed expressed sequence tag analyses of 3 and 5 d cultures indicate that most sequences are related to pollen-specific genes. However, semiquantitative and real-time reverse transcription-polymerase chain reaction analyses at the initial stages of embryo induction also reveal expression of embryogenesis-related genes such as BABYBOOM1, LEAFY COTYLEDON1 (LEC1), and LEC2 as early as 2 to 3 d of microspore culture. Sequencing results suggest that embryogenesis is clearly established in a subset of the microspores by 7 d of culture and that this time point is optimal for isolation of embryo-specific expressed sequence tags such as ABSCISIC ACID INSENSITIVE3, ATS1, LEC1, LEC2, and FUSCA3. Following extensive polymerase chain reaction-based expression profiling, 16 genes were identified as unequivocal molecular markers for microspore embryogenesis in B. napus. These molecular marker genes also show expression during zygotic embryogenesis, underscoring the common developmental pathways that function in zygotic and gametic embryogenesis. The quantitative expression values of several of these molecular marker genes are shown to be predictive of embryogenic potential in B. napus cultivars (e.g. ‘Topas’ DH4079, ‘Allons,’ ‘Westar,’ ‘Garrison’).
Malik, Meghna R.; Wang, Feng; Dirpaul, Joan M.; Zhou, Ning; Polowick, Patricia L.; Ferrie, Alison M.R.; Krochko, Joan E.
To understand the mechanism in induction of embryogenesis from microspores of Brassica napus, we isolated exhaustively the genes expressed differentially during the early stage of microspore culture. A subtracted cDNA\\u000a library composed of up-regulated genes during androgenic initiation was produced by suppression subtractive hybridization\\u000a followed by differential screening by dot blot hybridization, and a total of 136 non-redundant expressed sequence
Pollen embryogenesis occurred in anther cultures of two genotypes ofBrassica carinata A. Braun. Pretreatment of anthers at 35°C for 3 or 6 days was essential for the induction of androgenesis on growth regulator-free\\u000a culture medium. A combination of sucrose and glucose was better than sucrose alone. None of the pollen embryos germinated\\u000a normally. Full plants were raised through adventitious bud
Somatic hypermutation (SHM) introduces mutations in the variable region of immunoglobulin genes at a rate of ?10?3 mutations per base pair per cell division, which is 106-fold higher than the spontaneous mutation rate in somatic cells. To ensure genomic integrity, SHM needs to be targeted specifically to immunoglobulin genes. The rare mistargeting of SHM can result in mutations and translocations
This volume traces the major developments of somatic cell genetics via 47 critical papers on somatic cell hybridization, gene transfer, and mutant mammalian cells. Recognized authorities emphasize the importance of applying the combined approach of cell genetics and recombinant DNA to questions of developments, regulations, and growth of both normal and tumor cells.
In some species of hagfish, the phenomenon of chromosome elimination occurs during embryogenesis. However, only two repetitive\\u000a DNA families are known to be represented in chromosomes that are eliminated from somatic cells of the Japanese hagfish Eptatretus okinoseanus. Using molecular analyses, another germ line-restricted, highly repetitive DNA family has been detected in another Japanese\\u000a hagfish, Paramyxine atami. The repeat unit
Feijoa (Acca sellowiana, Myrtaceae), a native fruit species from southern Brazil and northern Uruguay, is considered to constitute a reference system\\u000a for somaticembryogenesis 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
Gabriela Claudia Cangahuala-Inocente; Andrea Villarino; Daniela Seixas; Eliane Dumas-Gaudot; Hernán Terenzi; Miguel Pedro Guerra
Oil palm (Elaeis guineensis Jacq.) is a plant with highest productivity of oil among others oil-producing plants with total product per year is 5-6 ton\\/ha. Micropropagation of oil palm by somaticembryogenesis has several advantages: homogenous plants, higher production of fresh fruit bunches and larger amount of high quality seeds in a relatively shorter time. Oil palm 635 clone (15
A significant proportion of patients seen in the Emergency Department will present with somatic complaints for which there is no apparent physiologic cause. Such patients may be divided into two broad categories: (1) those with symptoms and signs consciously synthesized by the patient, either for obvious secondary gain (malingering) or as a result of more subtle and complex motivations (factitious disorders); and (2) those patients with symptoms that are the unconscious expression of psychological stress (somatoform disorders). The somatoform disorders include (1) somatization disorder (characterized by a chronic history of numerous and widely divergent somatic complaints), (2) psychogenic pain disorder (somatization expressed in terms of persistent pain), (3) hypochondriasis (a conviction that one is diseased and disabled in conjunction with a well-focused constellation of supporting symptoms), and (4) conversion disorder (a single, usually nonpainful neurologic symptom, often with identifiable coping value for the patient). The first three disorders have been aggregately termed the "common somatization syndrome." Management of the somatically focused patient includes the communication of a caring attitude to the patient in conjunction with a cautious and diligent search for treatable medical or psychiatric illness. Resocialization and development of patient links with ongoing, nurturing nonmedical as well as medical support systems is of benefit. PMID:2001663
Papaya production is seriously limited by Papaya ringspot virus (PRSV) worldwide and Papaya leaf-distortion mosaic virus (PLDMV) in Eastern Asia. An efficient transformation method for developing papaya lines with transgenic resistance to these viruses and commercially desirable traits, such as hermaphroditism, is crucial to shorten the breeding program for this fruit crop. In this investigation, an untranslatable chimeric construct pYP08 containing truncated PRSV coat protein (CP) and PLDMV CP genes coupled with the 3' untranslational region of PLDMV, was generated. Root segments from different portions of adventitious roots of in vitro multiple shoots of hermaphroditic plants of papaya cultivars 'Tainung No. 2', 'Sunrise', and 'Thailand' were cultured on induction medium for regeneration into somatic embryos. The highest frequency of somaticembryogenesis was from the root-tip segments of adventitious roots developed 2-4 weeks after rooting in perlite medium. After proliferation, embryogenic tissues derived from somatic embryos were wounded in liquid-phase by carborundum and transformed by Agrobacterium carrying pYP08. Similarly, another construct pBG-PLDMVstop containing untranslatable CP gene of PLDMV was also transferred to 'Sunrise' and 'Thailand', the parental cultivars of 'Tainung No. 2'. Among 107 transgenic lines regenerated from 349 root-tip segments, nine lines of Tainung No. 2 carrying YP08 were highly resistant to PRSV and PLDMV, and 9 lines (8 'Sunrise' and 1 'Thailand') carrying PLDMV CP highly resistant to PLDMV, by a mechanism of post-transcriptional gene silencing. The hermaphroditic characteristics of the transgenic lines were confirmed by PCR with sex-linked primers and phenotypes of flower and fruit. Our approach has generated transgenic resistance to both PRSV and PLDMV with commercially desirable characters and can significantly shorten the time-consuming breeding programs for the generation of elite cultivars of papaya hybrids. PMID:19943109
Transglutaminase (TG) has been examined in different stages of preimplantation mouse embryogenesis. The specific activity of this enzyme in the soluble cellular fraction increases 2-fold from 2-cell embryos to 8-cell morulae and 4-fold from 2-cell embryos to blastocyst. The same developmental profile was seen when either N,N-dimethylcasein or endogenous substrates were used in the TG assay. Using high-speed supernatants from different stage embryos as a source of enzyme and (/sup 3/H)putrescine as acyl acceptor, the major acyl donor components were tubulin and a high molecular weight (HMW) cross-linkage product, as assessed by electrophoresis and immunoblotting. When either assembled or monomeric cytoskeleton proteins were compared as subtrates, microtubules were the best acyl donors. These studies indicate that TG activity is modulated during the changing demands of blastomeres for microtubule cytoskeleton in early embryogenesis.
|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…
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…
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.
I. Wilmut; N. Beaujean; P. A. de Sousa; A. Dinnyes; T. J. King; L. A. Paterson; D. N. Wells; L. E. Young
Somatic cell nuclear transfer (SCNT), the technique commonly known as cloning, permits transformation of a somatic cell into an undifferentiated zygote with the potential to develop into a newborn animal (i.e., a clone). In somatic cells, chromatin is programmed to repress most genes and express some, depending on the tissue. It is evident that the enucleated oocyte provides the environment in which embryonic genes in a somatic cell can be expressed. This process is controlled by a series of epigenetic modifications, generally referred to as "nuclear reprogramming," which are thought to involve the removal of reversible epigenetic changes acquired during cell differentiation. A similar process is thought to occur by overexpression of key transcription factors to generate induced pluripotent stem cells (iPSCs), bypassing the need for SCNT. Despite its obvious scientific and medical importance, and the great number of studies addressing the subject, the molecular basis of reprogramming in both reprogramming strategies is largely unknown. The present review focuses on the cellular and molecular events that occur during nuclear reprogramming in the context of SCNT and the various approaches currently being used to improve nuclear reprogramming. A better understanding of the reprogramming mechanism will have a direct impact on the efficiency of current SCNT procedures, as well as iPSC derivation. PMID:22979962
Background Smad ubiquitination regulatory factor (Smurf) 1 and 2 are E3 ubiquitin ligases originally identified as inhibitors of transforming growth factor beta signaling and are shown to modulate multiple cellular activities. The roles of Smurfs in vertebrate embryogenesis, however, are not completely understood. Results Here we investigate the function of Smurf2 during early Xenopus development. We show that distinctly from Smurf1, overexpression of Smurf2 in presumptive mesoderm interfered with mesoderm induction and caused axial defects, whereas knockdown of Smurf2 with antisense morpholino oligonucleotides resulted in expansion of the mesoderm. These results imply that Smurf2 may modulate nodal-mediated mesodermal induction. Consistently, ventral expression of Smurf2 induced a partial secondary axis with head structures. In the ectoderm, Smurf2 resembled Smurf1 in controlling neural and epidermal marker expression and influencing head formation. Smurf1, but not Smurf2, additionally affected neural tube closure. Interestingly, both Smurfs could enhance as well as repress neural crest markers, implying that they modulate their targets dynamically during neural plate border specification. Conclusion Our data demonstrate that Smurf1 and Smurf2 have overlapping and distinct functionalities during early frog embryogenesis; collectively, they regulate ectodermal and mesodermal induction and patterning to ensure normal development of Xenopus embryos.
Promoters of the late embryogenesis abundant protein genes, HVA1s, Dhn8s and Dhn4s from barley and wsi18j and rab16Bj from rice, were analysed in barley seedlings to assess their strength and timing of induction under water deficit conditions using a transient expression system. Of the drought-inducible promoters, Dhn4s exhibited the highest activity, followed by HVA1s, wsi18j and rab16Bj. Dehydration-induced #-glucuronidase expression
Somatic embryo-like structures were produced from the hypocotyls of ten cultivars of Pelargonium x hortorum using the protocols of Marsolais et al. (1991; Can J Bot 69:1188-1193) and Slimmon et al. (1991; Plant Cell Rep 10:587-589) and their embryonic natures evaluated. Nine cultivars responded, and 937 structures were formed. Regeneration corresponded well with published data. The somatic embryo-like structures were globular- to leaf-shaped or similar to shoots. A root pole was never visible. Histological examinations confirmed the lack of bipolarity and revealed vascular connections to the explant in the more developed structures. Therefore, these structures cannot be classified as somatic embryos. The importance of these results is discussed in terms of evaluating published protocols for the propagation of these pelargoniums by somaticembryogenesis from hypocotyls. PMID:14569413
Hydra's remarkable capacity to regenerate, to proliferate asexually by budding, and to form a pattern de novo from aggregates allows studying complex cellular and molecular processes typical for embryonic development. The underlying assumption is that patterning in adult hydra tissue relies on factors and genes which are active also during early embryogenesis. Previously, we reported that in Hydra the timing of expression of conserved regulatory genes, known to be involved in adult patterning, differs greatly in adults and embryos (Fröbius, A.C., Genikhovich, G., Kürn, U., Anton-Erxleben, F. and Bosch, T.C.G., 2003. Expression of developmental genes during early embryogenesis of Hydra. Dev. Genes Evol. 213, 445-455). Here, we describe an unbiased screening strategy to identify genes that are relevant to Hydra vulgaris embryogenesis. The approach yielded two sets of differentially expressed genes: one set was expressed exclusively or nearly exclusively in the embryos, while the second set was upregulated in embryos in comparison to adult polyps. Many of the genes identified in hydra embryos had no matches in the database. Among the conserved genes upregulated in embryos is the Hydra orthologue of Embryonic Ectoderm Development (HyEED). The expression pattern of HyEED in developing embryos suggests that interstitial stem cells in Hydra originate in the endoderm. Importantly, the observations uncover previously unknown differences in genes expressed by embryos and polyps and indicate that not only the timing of expression of developmental genes but also the genetic context is different in Hydra embryos compared to adults. PMID:16337937
Genikhovich, Grigory; Kürn, Ulrich; Hemmrich, Georg; Bosch, Thomas C G
A computer vision system was developed for the classification of plant somatic embryos. The embryos are in a Petri dish that is transferred with constant speed and they are recognized as they pass a line scan camera. A classification algorithm needs to be installed for every plant species. This paper describes an algorithm for the recognition of Norway spruce (Picea abies) embryos. A short review of conifer micropropagation by somaticembryogenesis is also given. The recognition algorithm is based on features calculated from the boundary of the object. Only part of the boundary corresponding to the developing cotyledons (2 - 15) and the straight sides of the embryo are used for recognition. An index of the length of the cotyledons describes the developmental stage of the embryo. The testing set for classifier performance consisted of 118 embryos and 478 nonembryos. With the classification tolerances chosen 69% of the objects classified as embryos by a human classifier were selected and 31$% rejected. Less than 1% of the nonembryos were classified as embryos. The basic features developed can probably be easily adapted for the recognition of other conifer somatic embryos.
Investigation of reproductive development of higher plants in spaceflight represents scientific interest first of all with the necessity to work out the plant space technologies for creation of controlled life-support systems. In such systems mainly the higher plants are considered to be an important component that makes it necessary to obtain the several generations of higher plants with their full ontogenesis. As a rule, seeds obtained in three species of the higher plants in a series of experiments differ from the control by some parameters (Merkis, Laurinavichius, 1983; Musgrave et al., 1998; 2000; Levinskikh et all. 1999; Stankovich et al., 2002). It was shown, that immature embryos generated in microgravity were at a range of developmental stage, while the ground control embryos had all reached the premature stage of development (Kuang et al., 2003). Besides, the distinctions in a degree of nutrient substances accumulation in them were revealed (Kuang et al., 2000). Therefore, the elucidation of the possible reasons for distortion of plant reproduction in microgravity demands the further research. In this study we examined embryogenesis of higher plant Brassica rapa L. with an application of slow horizontal clinostats, that allows to deprive the plants the opportunity to perceive the gravitational stimulus. Some plants were clinorotated from the moment sowing of seeds; in other series the experiment plants were placed on clinostats after formation of flower buds. Temporal fixation of the material was used in these experiments, which allow to obtain material for studying of consecutive stages of embryogenesis. The development of 2-21 day-old embryos was studied. Comparative embryological analysis has shown a similarity in the main of process of embryo differentiation produced under clinorotation and in the stationary control. At the early stages of embryogenesis, the distortion in suspensor formation was observed more frequently. Embryos generated in clinorotation variant had a wider range of developmental stages in comparison with the stationary control. At the stage of embryo maturation the various deviations in embryo differentiation were revealed. These distortions were connected both with cotyledon and radicle development. Possible reasons for deviations in the process of embryogenesis in condition of altered gravity are discussed.
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.
Malik, Meghna R.; Wang, Feng; Dirpaul, Joan M.; Zhou, Ning; Hammerlindl, Joe; Keller, Wilf; Abrams, Suzanne R.; Ferrie, Alison M. R.; Krochko, Joan E.
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),
C. Y. Shao; E. Russinova; A. Iantcheva; A. Atanassov; A. McCormac; D. F. Chen; M. C. Elliott; A. Slater
Summary The influences of various carbohydrate sources, dried yeast (DY), and 6-benzylaminopurine (BA) were estimated on growth and\\u000a development of shoot tip-derived suspension cells of phalaenopsis orchid. Among the carbohydrates tested on Doriataenopsis cultured on gelled medium, glucose at 58.4 mM gave the highest efficiency of protocorm-like body (PLB) formation. Maltose and sorbitol only induced PLB formation without\\u000a callus proliferation. Sucrose
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
Mohd Zahid Rizvi; Arun Kumar Kukreja; Narendra Singh Bisht
Callus was obtained from segments of immature inflorescence of Coix lacryma-jobi cultured on N6 medium containing 1–2 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 3–5% sucrose. Plantlets were regenerated when embryogenic calluses were transferred onto MS medium with 0.5 mg\\/l kinetin and 0.01 mg\\/l naphthaleneacetic acid (NAA). Regenerated plants had the diploid chromosome number (2n=20).
Complete plants were grown from zygotic embryos cultured on Y3 basal liquid medium supplemented with coconut milk, BA and NAA. Explants from stem, leaf and rachilla of mature coconut trees turned green and swelled on Y3 semi-solid basal media supplemented with 2,4-D, K, NAA, BA and activated charcoal. Callus was initiated in explants from the subapical regions of the stem
P. K. Gupta; S. V. Kendurkar; V. M. Kulkarni; M. V. Shirgurkar; A. F. Mascarenhas
Non-embryogenic cells (NEC) and embryogenc cells (EC) were separated from cell clusters derived from the hypocotyl segments\\u000a of celery seedlings, which had been suspension-cultured in MS medium supplemented with 105 M 2,4-D. The EC formed globular embryos in medium without 2,4-D. The globular embryo developed through heart-shaped, torpedo\\u000a to cotyledonary embryos within 10 days. The EC and developing embryos were
Shoot tips and leafy bud fragments removed from offshoots of adult date palms (Phoenix dactylifera L.) were cultured on a nutrient medium containing the Murashige and Skoog inorganic salts, 453 µM 2,4-dichlorophenoxyacetic acid, 14.8 µM N6-(2-isopentenyl)adenine and 3 g l-1 activated charcoal to develop nodular callus after 8 months of culture. Callus was cultured in agar-solidified and stationary or shaken
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 cul...
R. G. Butenko N. N. Dmitriyeva V. Ongko L. V. Basyrova
Summary Embryogenic callus was initiated from radicles of mature embryos removed from imbibed seeds (24 h). Embryogenic and other\\u000a nonembryogenic types of callus proliferated on a modified half-strength Murashige-Skoog medium (MS) basal medium (BM) supplemented\\u000a withmyo-inositol, casein hydrolysate (CH), L-glutamine (gln) and growth regulators kinetin (KN), N6-benzyladenine (BAP) each (2010?6\\u000a M), 2,4-dichlorophenoxyacetic acid (2,4-D) (5010?6\\u000a M) Embryogenic callus bearing suspensor-like cells
Embryogenic tissue was produced from kernels of immature fruits of Pistachio (Pistacia vera L.) cultured in liquid Murashige and Skoog media, supplemented with 200 mgl-1 casein hydrolysate, 114 µM 1-ascorbic acid, and benzylaminopurine. Compact embryogenic masses differentiated directly from the fruit explants after culture for 2 weeks in liquid medium with 8.9 µM benzylaminopurine. After transfer of the embryogenic masses
Yellow pitaya (Mediocactus coccineus) seeds were sown on Murashige and Skoog (1962) mineral salt medium. After germination, epicotyls were placed on media enriched with a combination of naphthaleneacetic acid (NAA) (0.05, 0.27 or 0.54 µM) and benzyladenine (BA) (2.2 or 4.4 µM). The apical tip was excised from half of the shoots and the other half were kept intact. Different
Embryogenic cell suspensions of Lavatera thuringiaca L. were established from leaf petiole and shoot regeneration was achieved when cells were plated on medium without growth regulators. We tested three methods for protoplast culture, isolated from a one-year old embryogenic cell suspension, to determine the best conditions for L. thuringiaca protoplast culture and shoot regeneration. The highest protoplast plating efficiency was
Fig is one of the most important fruit trees in Egypt. It used to constitute the major source of income for the inhabitants of the western north coast of Egypt. Since 1993 fig cultivations were threatened by a number of factors including virus, insect and mite infections. An efficient system for regeneration and transformation of the common fig Ficus carica L. cultivar Sultani (fresh consumption) was required to conserve fig cultivation in the area. The effect of different combinations of BA and NAA/2,4-D and kinetin on callus formation from leaf segments were studied. Results showed that the best medium for callus formation was MS supplemented with 2.0 mg/l 2,4-D and 0.2 mg/l kinetin. The best plantlet differentiation was obtained at concentrations of 30 mg/l 2iP and 7 mg/l TDZ with 0.25 mg/l NAA (with a regeneration efficiency of 83 and 79%, respectively). On the other hand, the obtained callus failed to induce organogenesis on media containing a combination of BA and kinetin. The highest shoot formation percentage (89%) was obtained when using 2 mg/l TDZ and 4 mg/l 2iP. The highest percentage of shoots forming roots (95%) was obtained when using MS medium supplemented with 1.0 mg/l IBA. Explants were transformed using Agrobacterium and microprojectile bombardment using the plasmid pISV2678 which harbors the gus-intron and bar genes. Results showed that the highest transformation efficiency using the Agrobacterium (17.5%) was obtained when explants were co-cultivated with the bacteria for 30 min. The highest transformation efficiency recorded using the microprojectile bombardment (12%) was obtained with 2.0 ?g DNA per shot at 1,100 psi and a distance of 6 cm repeated twice. The transgenic nature of regenerated plants was confirmed by PCR analysis, histochemical GUS assay and leaf painting assay. PMID:21912211
Soliman, Hemaid Ibrahim; Gabr, Mahdia; Abdallah, Naglaa A
\\u000a Plant regeneration from immature embryos may follow different pathways. First, one may distinguish between a direct and an\\u000a indirect way. The former implies the de novo development of meristems on the immature embryo from which new expiants originate.\\u000a In the case of indirect regeneration, the development of new plantlets from the expiant is interrupted by an intervening callus\\u000a phase. A
Reprogramming of adult somatic cells into pluripotent stem cells may provide an attractive source of stem cells for regenerative medicine. It has emerged as an invaluable method for generating patient-specific stem cells of any cell lineage without the use of embryonic stem cells. A revolutionary study in 2006 showed that it is possible to convert adult somatic cells directly into pluripotent stem cells by using a limited number of pluripotent transcription factors and is called as iPS cells. Currently, both genomic integrating viral and nonintegrating nonviral methods are used to generate iPS cells. However, the viral-based technology poses increased risk of safety, and more studies are now focused on nonviral-based technology to obtain autologous stem cells for clinical therapy. In this review, the pros and cons of the present iPS cell technology and the future direction for the successful translation of this technology into the clinic are discussed. PMID:22917226
In response to an assault by foreign organisms, peripheral B cells can change their antibody affinity and isotype by somatically mutating their genomic DNA. The ability of a cell to modify its DNA is exceptional in light of the potential consequences of genetic alterations to cause human disease and cancer. Thus, as expected, this mechanism of antibody diversity is tightly regulated and coordinated through one protein, activation induced deaminase (AID). AID produces diversity by converting cytosine to uracil within the immunoglobulin loci. The deoxyuracil residue is mutagenic when paired with deoxyguanosine, since it mimics thymidine during DNA replication. Additionally, B cells can manipulate the DNA repair pathways so that deoxyuracils are not faithfully repaired. Therefore, an intricate balance exists which is regulated at multiple stages to promote mutation of immunoglobulin genes, while retaining integrity of the rest of the genome. Here we discuss and summarize the current understanding of how AID functions to cause somatic hypermutation.
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.
Dr. Anita G Fernandez (Fairfield University Biology); Ian Chin-Sing (Queens University)
Our laboratory investigates systemic autoimmune disease in the context of mouse models of systemic lupus erythematosus (SLE). SLE is associated with high titers of serum autoantibodies of the IgG class that are predominantly directed against nuclear antigens, with pathological manifestations that are considered by many to be characteristic of an immune-complex mediated disease. In this review, we focus on the known and potential roles of somatic mutagenesis in SLE. We will argue that anti-nuclear antibodies (ANA) arise predominantly from nonautoreactive B cells that are transformed into autoreactive cells by the process of somatic hypermutation (SHM), which is normally associated with affinity maturation during the germinal center reaction. We will also discuss the role of SHM in creating antigenic peptides in the V region of the B cell receptor (BCR) and its potential to open an avenue of unregulated T cell help to autoreactive B cells. Finally, we will end this review with new experimental evidence suggesting that spontaneous somatic mutagenesis of genes that regulate B cell survival and activation is a rate-limiting causative factor in the development of ANA. PMID:23249093
Detanico, Thiago; St Clair, James B; Aviszus, Katja; Kirchenbaum, Greg; Guo, Wenzhong; Wysocki, Lawrence J
In order to validate the propagation technology of Coffea canephoraPierre var. Robusta via somaticembryogenesis in liquid medium, the clonal fidelity of regenerated trees has been assessed\\u000a for the first time in large-scale field trials. A total of 5067 trees originating from 5- to 7-month-old embryogenic cell\\u000a suspension cultures were planted in the Philippines and in Thailand for comparing with
J. P. Ducos; R. Alenton; J. F. Reano; C. Kanchanomai; A. Deshayes; V. Pétiard
Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen. For avians (chicks’ and turkeys’ embryos), it has been shown that, a few days after fertilization, the mucosal epithelium of the duodenum is smooth, and then folds emerge, which present 2 d later a pronounced zigzag instability. Many debates and biological studies are devoted to this specific morphology, which regulates the cell renewal in the intestine. After reviewing experimental results about duodenum morphogenesis, we show that a model based on simplified hypothesis for the growth of the mesenchyme can explain buckling and postbuckling instabilities. Being completely analytical, it is based on biaxial compressive stresses due to differential growth between layers and it predicts quantitatively the morphological changes. The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability. The model is compared with available experimental data on chick’s duodenum and can be applied to other intestinal tissues, the zigzag being a common and spectacular microstructural pattern of intestine embryogenesis.
In this study, efficient plant regeneration through somaticembryogenesis is achieved in four cultivars of carnation (Nelson, Sagres, Spirit and Impulse). Embryogenic calli were induced on petal explants only, all the calli established on leaf, sepal, receptacle and style explants were not embryogenic. Embryogenic calli were obtained on Morashige and Skoog basal medium (1962) containing sucrose 9%, 2.0 mg L?1
At a nonpermissive temperature, somatic embryos of the temperature-sensitive (ts) carrot cell mutant ts11 only proceed beyond the globular embryo stage in the presence of medium conditioned by wild-type embryos. The causative component in the conditioned medium has previously been identified as a 32-kD acidic endochitinase. In search of a function for this enzyme in plant embryogenesis, several compounds that contain oligomers of N-acetylglucosamine were tested for their ability to promote ts11 embryo formation. Of these compounds, only the Rhizobium lipooligosaccharides or nodulation (Nod) factors were found to be effective in rescuing the formation of ts11 embryos. These results suggest that N-acetylglucosamine-containing lipooligosaccharides from bacterial origin can mimic the effect of the carrot endochitinase. This endochitinase may therefore be involved in the generation of plant analogs of the Rhizobium Nod factors.
De Jong, AJ; Heidstra, R; Spaink, HP; Hartog, MV; Meijer, EA; Hendriks, T; Schiavo, FL; Terzi, M; Bisseling, T; Van Kammen, A; De Vries, SC
Agrobacterium tumefaciens strain KYRT1 harboring the virulence helper plasmid pKYRT1 induces transgenic somatic embryos (SEs) at high frequency from infected immature soybean cotyledons. KYRT1 is derived from the highly oncogenic strain Chry5. However, pKYRT1 is not completely disarmed and still contains an entire T-right (T(R)) and a portion of T-left (T(L)). In this report, binary strains, each carrying fully disarmed vir helper plasmids including pKPSF2, which is a fully disarmed version of pKYRT1, were compared to strain KYRT1 for their ability to induce transgenic SEs on immature cotyledons of soybean. Six weeks following cocultivation, histochemical GUS assays of cultured explants indicated that all fully disarmed vir helper plasmids transferred their binary T-DNA, containing a GUS-intron gene, into soybean tissues. However, none of these transformed tissues developed SEs on medium with or without 2,4-dichlorophenoxyactic acid (2,4-D). On the other hand, immature cotyledons cocultivated with strain KYRT1 exhibited high induction of transgenic SEs, but only on medium supplemented with 2,4-D. Derivatives of strain Chry5 harboring other vir helper plasmids did not induce transgenic SEs under any conditions tested, thus suggesting that the chromosomal background of KYRT1 alone was not sufficient to promote somaticembryogenesis. PCR analysis indicated that 55% of transgenic embryogenic cultures and 29% of transgenic T(0) soybean plants derived by transformation using strain KYRT1 contained T(R) from pKYRT1 in addition to the uidA gene from the binary construct. None of the transgenic tissues or T(0) plants contained T(L) DNA. These results suggest that some function coded for by T(R) of pKYRT1 influences somaticembryogenesis in conjunction with exposure of the plant tissues to 2,4-D. Since the co-transformation frequency of the undesirable T-DNA sequences from the vir helper plasmid was relatively low, the partially disarmed strain KYRT1 will likely be very useful for the production of normal transgenic plants of diverse soybean cultivars. PMID:14618322
Ko, Tae-Seok; Lee, Sangman; Farrand, Stephen K; Korban, Schuyler S
Modern studies of the genetic control of development have increased the need for an accurate and comprehensive storage and display of gene expression data. This can be achieved in the form of an electronic graphic database of development. Here, we introduce the first steps towards a database of Drosophila embryogenesis. For each morphologically defined stage, a complete series of histological and/or optical sections are generated (optical sections are generated by laser confocal microscopy). Digitized sections are imported into a drawing program where they serve as templates to define the contours of organs and the position of individual cells. From these data, surface and point cloud models of all developmental stages are generated. Gene expression data can be entered by translating the expression domain of a given gene into the three-dimensional coordinate system of the database. PMID:7716807
Embryogenic suspensions that involve extensive cell division are risky in respect to genome and epigenome instability. Elevated frequencies of somaclonal variation in embryogenic suspension-derived plants were reported in many species, including coffee. This problem could be overcome by using culture conditions that allow moderate cell proliferation. In view of true-to-type large-scale propagation of C. arabica hybrids, suspension protocols based on low 2,4-D concentrations and short proliferation periods were developed. As mechanisms leading to somaclonal variation are often complex, the phenotypic, genetic and epigenetic changes were jointly assessed so as to accurately evaluate the conformity of suspension-derived plants. The effects of embryogenic suspensions and secondary embryogenesis, used as proliferation systems, on the genetic conformity of somaticembryogenesis-derived plants (emblings) were assessed in two hybrids. When applied over a 6 month period, both systems ensured very low somaclonal variation rates, as observed through massive phenotypic observations in field plots (0.74% from 200 000 plant). Molecular AFLP and MSAP analyses performed on 145 three year-old emblings showed that polymorphism between mother plants and emblings was extremely low, i.e. ranges of 0–0.003% and 0.07–0.18% respectively, with no significant difference between the proliferation systems for the two hybrids. No embling was found to cumulate more than three methylation polymorphisms. No relation was established between the variant phenotype (27 variants studied) and a particular MSAP pattern. Chromosome counting showed that 7 of the 11 variant emblings analyzed were characterized by the loss of 1–3 chromosomes. This work showed that both embryogenic suspensions and secondary embryogenesis are reliable for true-to-type propagation of elite material. Molecular analyses revealed that genetic and epigenetic alterations are particularly limited during coffee somaticembryogenesis. The main change in most of the rare phenotypic variants was aneuploidy, indicating that mitotic aberrations play a major role in somaclonal variation in coffee.
– \\u000a \\u000a • Development of both somatic and gametic embryogenesis has many applications in clonal forestry and genetic improvement,\\u000a for instance as mass-propagation of genetically improved plants and production of pure lines through doubled-haploid plant\\u000a regeneration from gametic embryos.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • The goal of this work was to improve growth, maturation and plantlet regeneration of cork oak (Quercus suber L.) embryos
Beatriz Pintos; Jose A. Manzanera; M. Angeles Bueno
Somatic musical exposure system for a person, preferably in recumbent position on substantially rigid supporting means. Music emanates from an air chamber in a sound housing spaced apart from the person-supporting means. A relatively fixed frame carries the person-supporting means and also the sound housing, at least the former and optionally the latter being resiliently mounted relative to the frame and thereby partly decoupled therefrom. Such resilient mounting is preferably provided by elastomeric means intervening between the frame and the means resiliently supported thereby and extending both lengthwise and widthwise. Striplike resilient mounting means preferably extends both along peripheral edges of the person-supporting means and transversely thereof between its ends.
Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early embryogenesis. Whether, however, Hydra embryogenesis is governed by the same mechanisms which are controlling adult patterning, remains to be shown. In this paper, in precisely staged Hydra embryos, we examined the expression pattern of 15 regulatory genes shown previously to play a role in adult patterning and cell differentiation. RT-PCR revealed that most of the genes examined were expressed in rather late embryonic stages. In situ hybridization, nuclear run-on experiments, and staining of nucleolar organizer region-associated proteins indicated that genes expressed in early embryos are transcribed in the engulfed "nurse cells" (endocytes). This is the first direct evidence that endocytes in Hydra not only provide nutrients to the developing oocyte but also produce maternal factors critical for embryogenesis. Our findings are an initial step towards understanding the molecular machinery controlling embryogenesis of a key group of basal metazoans and raise the possibility that in Hydra there are differences in the mechanisms controlling embryogenesis and adult patterning. PMID:12883882
Fröbius, Andreas C; Genikhovich, Gregory; Kürn, Ulrich; Anton-Erxleben, Friederike; Bosch, Thomas C G
Somatic-embryogenic competence of eleven cassava genotypes was determined in induction media containing 8 and 12 mg\\/l of the auxin picloram, using axillary meristems and leaf lobes as explants. There were significant differences (p<0.01) among the cassava genotypes for ability to form somatic embryos. Proembryo formation took between 27 to 35 days and ranged between 34.5% for TME 596 and 0%
A 10-mG, 50 to 60-Hz magnetic field is in the intensity and frequency range that people worldwide are often exposed to in homes and in the workplace. Studies about the effects of 50- to 100-Hz electromagnetic fields on various species of animal embryos (fish, chick, fly, sea urchin, rat, and mouse) indicate that early stages of embryonic development are responsive to fluctuating magnetic fields. Chick, sea urchin, and mouse embryos are responsive to magnetic field intensities of 10-100 mG. Results from studies on sea urchin embryos indicate that exposure to conditions of rotating 60-Hz magnetic fields, e.g., similar to those in our environment, interferes with cell proliferation at the morula stage in a manner dependent on field intensity. The cleavage stages, prior to the 64-cell stage, were not delayed by this rotating 60-Hz magnetic field suggesting that the ionic surges, DNA replication, and translational events essential for early cleavage stages were not significantly altered. Studies of histone synthesis in early sea urchin embryos indicated that the rotating 60-Hz magnetic field decreased zygotic expression of early histone genes at the morula stage and suggests that this decrease in early histone production was limiting to cell proliferation. Whether these comparative observations from animal development studies will be paralleled by results from studies of human embryogenesis, as suggested by some epidemiology studies, has yet to be established. 38 refs.
Cameron, I.L.; Hardman, W.E.; Winters, W.D.; Zimmerman, S.; Zimmerman, A.M. (Univ. of Texas Health Science Center, San Antonio (United States))
Biologists have extensively studied embryonic development in the fruit fly (Drosophila melangaster) as a model for morphogenesis. Our overall goal is to understand how the cellular rearrangements of morphogenesis are caused by the underlying forces between cells. To that end, we are developing means to replicate fruit fly embryogenesis (from cellular differentiation to dorsal closure) using cellular Potts models. Cells are described as collections of like ``spins''; and spin-spin interaction energies are used to describe the forces along cell boundaries. Using a four state (spin-type) model (three tissue types and the surrounding media) we have reproduced cell sorting as well as engulfment of a surface grouping of tissue. Cell sorting can be accomplished using only the spin-spin interaction energies with the volume components being used only for cell size management. We are currently attempting to replicate the experimentally determined geometry and dynamics of dorsal closure. This modeling will take advantage of software tools developed at Notre Dame for looking at cellular Potts models and packaged as CompuCell3D.
Background Describing the patterns of gene expression during embryonic development has broadened our understanding of the processes and patterns that define morphogenesis. Yet gene expression patterns have not been described throughout vertebrate embryogenesis. This study presents statistical analyses of gene expression during all 40 developmental stages in the teleost Fundulus heteroclitus using four biological replicates per stage. Results Patterns of gene expression for 7,000 genes appear to be important as they recapitulate developmental timing. Among the 45% of genes with significant expression differences between pairs of temporally adjacent stages, significant differences in gene expression vary from as few as five to more than 660. Five adjacent stages have disproportionately more significant changes in gene expression (> 200 genes) relative to other stages: four to eight and eight to sixteen cell stages, onset of circulation, pre and post-hatch, and during complete yolk absorption. The fewest differences among adjacent stages occur during gastrulation. Yet, at stage 16, (pre-mid-gastrulation) the largest number of genes has peak expression. This stage has an over representation of genes in oxidative respiration and protein expression (ribosomes, translational genes and proteases). Unexpectedly, among all ribosomal genes, both strong positive and negative correlations occur. Similar correlated patterns of expression occur among all significant genes. Conclusions These data provide statistical support for the temporal dynamics of developmental gene expression during all stages of vertebrate development.
The cell biological events that guide early embryonic development occur with great precision within species but can be quite diverse across species. How these cellular processes evolve and which molecular components underlie evolutionary changes is poorly understood. To begin to address these questions, we systematically investigated early embryogenesis, from the one- to the four-cell embryo, in 34 nematode species related to C. elegans. We found 40 cell-biological characters that captured the phenotypic differences between these species. By tracing the evolutionary changes on a molecular phylogeny, we found that these characters evolved multiple times and independently of one another. Strikingly, all these phenotypes are mimicked by single-gene RNAi experiments in C. elegans. We use these comparisons to hypothesize the molecular mechanisms underlying the evolutionary changes. For example, we predict that a cell polarity module was altered during the evolution of the Protorhabditis group and show that PAR-1, a kinase localized asymmetrically in C. elegans early embryos, is symmetrically localized in the one-cell stage of Protorhabditis group species. Our genome-wide approach identifies candidate molecules—and thereby modules—associated with evolutionary changes in cell-biological phenotypes.
Brauchle, Michael; Kiontke, Karin; MacMenamin, Philip; Fitch, David H. A.; Piano, Fabio
Somaticembryogenesis in gymnosperms is an effective approach to clonally propagating germplasm. However, embryogenic cultures frequently lose regenerative capacity. The interactions between metabolic composition, physiological state, genotype and embryogenic capacity in Pinus taeda (loblolly pine) somatic embryogenic cultures were explored using metabolomics. A stepwise modelling procedure, using the Bayesian information criterion, generated a 47 metabolite predictive model that could explain culture productivity. The model performed extremely well in cross-validation, achieving a correlation coefficient of 0.98 between actual and predicted mature embryo production. The metabolic composition and structure of the model implied that variation in culture regenerative capacity was closely linked to the physiological transition of cultures from the proliferation phase to the maturation phase of development. The propensity of cultures to advance into this transition appears to relate to nutrient uptake and allocation in vivo, and to be associated with the tolerance and response of cultures to stress, during the proliferation phase. PMID:19906246
Robinson, Andrew R; Dauwe, Rebecca; Ukrainetz, Nicholas K; Cullis, Ian F; White, Rick; Mansfield, Shawn D
In the present study, skin conductance responses (SCRs) were measured postdecision and prefeedback in a go\\/no-go (GNG) task\\u000a in which participants used response feedback to learn when to respond or not to respond to numeric stimuli. Like somatic markers\\u000a in gambling tasks and somatic reactions to error monitoring in choice reaction time tasks, SCR patterns distinguished between\\u000a correct and incorrect
Paul Whitney; John M. Hinson; Aaron Wirick; Heather Holben
The stability, both genetic and phenotypic, of potato (Solanum tuberosum L.) cultivar Desiree plants derived from alternative propagation methodologies has been compared. Plants obtained through\\u000a three clonal propagation routes—axillary-bud-proliferation, microtuberisation and a novel somaticembryogenesis system, and\\u000a through true potato seeds (TPS) produced by selfing were evaluated at three levels: gross phenotype and minituber yield, changes\\u000a in ploidy (measured by
Sanjeev Kumar Sharma; Glenn J. Bryan; Mark O. Winfield; Steve Millam
During neural induction, the `organizer' of the vertebrate embryo instructs neighbouring ectodermal cells to become nervous system rather than epidermis. This process is generally thought to occur around the mid-gastrula stage of embryogenesis. Here we report the isolation of ERNI, an early response gene to signals from the organizer (Hensen's node). Using ERNI as a marker, we present evidence that
Andrea Streit; Alyson J. Berliner; Costis Papanayotou; Andrés Sirulnik; Claudio D. Stern
In this work the influence of high concentration of antibodies to NGF on mouse's progeny has been investigated. During immunization with NGF the highest concentrations of antibodies were created in the first and third days of pregnancy (in different groups of animals). The dependence of abnormalities of mice postnatal development on level of antibodies to NGF at different stages of early embryogenesis has been established. Increasing of abnormalities in the formation of early behavioral acts and more clinically apparent anomalies in the somatic maturation in case of maximum of antibodies on day I of pregnancy has been showed. Immune responses to NGF during early embryogenesis of mice cause lag in the formation of behavioral acts. The latter are characterized by difficulties in sensor-motor coordination of the limbs and more clinically apparent in mice with a maximum of antibodies on day 1 of embryonic development. Infantilism in developing of contacts between progeny and mothers detected in mice with immune reactions may be a sign of serious mental dysontogenesis. The accelerated development of working memory established in mice with immune response to NGF requires further study of the development of cognitive abilities in these animals. The obtained results illustrate the important regulatory role of NGF at the early stages of development of the nervous system. PMID:23072115
Rodionov, A N; Lobanov, A V; Morozov, S G; Sidiakin, A A; Anikina, O M; Gribova, I E; Rybakov, A S; Protsenko, A N; Murashev, A N; Kliushnik, T P
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.
Schaefer, F.V.; Calikoglu, A.S.; Whetsell, L.H. [H.A. Chapman Research Institute of Medical Genetics, Tulsa, OK (United States)
Pleiotropy refers to the phenomenon in which a single gene controls several distinct, and seemingly unrelated, phenotypic effects. We use C. elegans early embryogenesis as a model to conduct systematic studies of pleiotropy. We analyze high-throughput RNA interference (RNAi) data from C. elegans and identify “phenotypic signatures”, which are sets of cellular defects indicative of certain biological functions. By matching phenotypic profiles to our identified signatures, we assign genes with complex phenotypic profiles to multiple functional classes. Overall, we observe that pleiotropy occurs extensively among genes involved in early embryogenesis, and a small proportion of these genes are highly pleiotropic. We hypothesize that genes involved in early embryogenesis are organized into partially overlapping functional modules, and that pleiotropic genes represent “connectors” between these modules. In support of this hypothesis, we find that highly pleiotropic genes tend to reside in central positions in protein-protein interaction networks, suggesting that pleiotropic genes act as connecting points between different protein complexes or pathways.
Biochemical signaling pathways in developmental processes have been extensively studied, yet the role of mechanical cues during embryogenesis is much less explored. Here we have used selective plane illumination microscopy in combination with a simple mechanical model to quantify and rationalize cell motion during early embryogenesis of the small nematode Caenorhabditis elegans. As a result, we find that cell organization in the embryo until gastrulation is well described by a purely mechanical model that predicts cells to assume positions in which they face the least repulsive interactions from other cells and the embryo’s egg shell. Our findings therefore suggest that mechanical interactions are key for a rapid and robust cellular arrangement during early embryogenesis of C. elegans.
Somatic symptoms are often common causes for medical consultation. The treatment of somatic symptoms disorders is complicated by lack of boundary, conceptual clarity, and overemphasis on psychosocial causation and effectiveness of psychological treatments. In clinical practice all classes of psychotropics are used to treat somatic symptoms disorder. Five principal groups of drugs such as tricyclic antidepressants (TCA), serotonin reuptake inhibitors (SSRI), serotonin and noradrenalin reuptake inhibitors (SNRI), atypical antipsychotics and herbal medication are systematically studied. The evidence indicates that all five groups are effective in a wide range of disorders. All classes of antidepressants seem to be effective against somatoform and related disorders. SSRIs are more effective against hypochondriasis and body dysmorphic disorder (BDD), and SNRIs appear to be more effective than other antidepressants when pain is the predominant symptom. Research leaves many unanswered questions regarding dosing, duration of treatment, sustainability of improvement in the long term and differential response to different class drugs. Further studies need to focus on treatments based on clinical features/psychopathology and collaborative research with other specialists in understanding the relation of somatic symptom disorders and functional somatic syndromes (FSS), and comparing psychotropics and non-psychotropics and combinations treatments. PMID:23383672
The developmental plasticity of plants is beautifully illustrated by the competence of the immature male gametophyte to change its developmental fate from pollen to embryo development when exposed to stress treatments in culture. This process, referred to as microspore embryogenesis, is widely exploited in plant breeding, but also provides a unique system to understand totipotency and early cell fate decisions. We summarize the major concepts that have arisen from decades of cell and molecular studies on microspore embryogenesis and put these in the context of recent experiments, as well as results obtained from the study of pollen and zygotic embryo development. PMID:23852380
Fusions between somatic cell lines have previously yielded evidence for the existence of trans-acting gene regulatory factors. For this reason, we developed a cell line containing a "locked in" human 11-X translocation chromosome (containing the beta-globin-like gene cluster) in MEL cells. The human 11-X chromosome is stably integrated in the "M11-X" cell line, and single-copy human gamma and beta genes are present. After induction with HMBA, M11-X cells produced 500 copies per cell of correctly initiated, processed, and terminated human beta-globin mRNA; authentic human beta-globin chains were also produced at a low level. Despite the presence of normally arranged human gamma-globin genes, no gamma-globin mRNA could be detected after HMBA induction. However, cytosine residues near the gamma-globin gene promoters are completely methylated in these cells, suggesting that the gamma-globin genes may be repressed in part by DNA methylation. The pattern of human globin gene expression in M11-X cells may be affected by methylation and/or by trans-acting factors produced by these tetraploid cells. PMID:6320217
Anderson, W F; Chiang, Y L; Sanders-Haigh, L; Ley, T J
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.
Rodriguez-Serrano, Maria; Barany, Ivett; Prem, Deepak; Coronado, Maria-Jose; Risueno, Maria C.; Testillano, Pilar S.
Third instar larvae of Drosophila melanogaster transdihybrid for mwh and flr were exposed to varying concentrations of cisplatin by feeding on dry media wetted with aqueous solutions of the test compound. Larval feeding continued until pupation, and surviving transdihybrid adults were collected seven days following commencement of feeding. Wings of adults were removed and scored under 400X magnification for the presence of twin spots and single spots comprised of clones of cells possessing malformed wing hairs. Cisplatin was found to induce both twin spots and single spots, and significant linear concentration-response relationships were obtained with respect to the induction of all endpoints. This capacity to induce mitotic exchange in the somatic tissue of Drosophila compares well with the compound's reported ability to induce chromosome breaks in Drosophila germ cells. However, not all compounds possess similar genotoxic profiles in the somatic an germ tissue of Drosophila.
During early mouse embryogenesis, temporal and spatial regulation of gene expression and cell signalling influences lineage specification, embryonic polarity, the patterning of tissue progenitors and the morphogenetic movement of cells and tissues. Uniquely in mammals, the extraembryonic tissues are the source of signals for lineage specification and tissue patterning. Here we discuss recent discoveries about the lead up to gastrulation,
During fruit fly embryogenesis, there are several morphogenetic events in which sheets of epithelial cells expand, contract and bend due to coordinated intra- and intercellular forces. This tissue-level reshaping is accompanied by changes in the shape and arrangement of individual cells -- changes that can be measured quantitatively and dynamically using modern live-cell imaging techniques. Such data sets represent rich
Gametogenesis fertilization and early embryogenesis are crucial periods for normal development afterwards In past three decades many experiments have been conducted in space and in simulated weightlessness induced by clinostats to elucidate the issue Different animal species including Drosophila wasp shrimp fish amphibian mouse rats etc have been used for the study Oogenesis and spermatogenesis are affected by microgravity in
Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early
Andreas C. Fröbius; Gregory Genikhovich; Ulrich Kürn; Friederike Anton-Erxleben; Thomas C. G. Bosch
Totipotency is the ability of a cell to regenerate the entire organism, even after previous differentiation as a specific cell. When totipotency is coupled with active cell division, it was presumed that cell division is essential for this expression. Here, using the stress-induction system of somatic embryos in carrots, we show that cell division is not essential for the expression of totipotency in somatic/embryonic conversion. Morphological and histochemical analyses showed that the cell did not divide during embryo induction. Inhibitors of cell division did not affect the rate of somatic embryo formation. Our results indicate that the newly acquired trait of differentiation appears without cell division, but does not arise with cell division as a newborn cell. PMID:22878456
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
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
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
Haldane's rule stating that viability and fertility in the heterogametic sex of hybrids are lower than in the homogametic sex is explained on the basis of the assumption that diploidy is aimed at protecting individuals having large body size and large genomes from somatic mutations. The presence of hemizygous sex chromosomes, which are effectively haploid in the heterogametic sex, results in the phenotypic expression of all deleterious somatic mutations arising in them. In the homogametic sex, somatic mutations that affect one out of two identical sex chromosomes are not expressed because the unaffected chromosome functions normally. Thus, the heterogametic sex is more sensitive to the harmful effect of somatic mutations. In hybrids, this difference may be critical. Consequently, when genetic distance between hybridizing species increases, the heterogametic sex of hybrids loses viability and fertility earlier than the homogametic sex, which agrees with Haldane's rule. On the basis of Haldane's rule and data on the small size of natural hybrid zones, restrictions on maximum heterozygosity compatible with viability were established. PMID:10505261
Soybean (Glycine max L. Merrill) somatic embryos have proven useful to assay seed-specific traits prior to plant recovery. The usefulness of soybean somatic embryos for the evaluation of seed-specific traits for transgenic or reverse genetics programs could be further enhanced if soybean somatic em...
The evidence supporting the reverse transcriptase model of somatic hypermutation is critically reviewed. The model provides a coherent explanation for many apparently unrelated findings. We also show that the somatic hypermutation pattern in the human BCL-6 gene can be interpreted in terms of the reverse transcriptase model and the notion of feedback of somatically mutated sequences to the germline over evolutionary time.
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,
Two field studies in two cities in Northrhine-Westfalia were carried out in order to characterize the degree of association between environmental odour-exposure, annoyance, and somatic symptoms. In both studies, odour effects were assessed through personal interviews by means of standardised questionnaires. In the first study, the odour source was a fertilizer plant for mushroom cultivation with particularly offensive odour emissions. The distance from the source was taken to characterize the intensity of odour exposure. 250 subjects were interviewed at close, medium or remote distance from the plant. Apart from an extremely high degree of annoyance, an increasing frequency of somatic symptoms was found with increasing proximity to the odour source. Somatic symptoms were directly linked to odour exposure and additionally mediated by annoyance. In the second study (n = 322), the odour source was a pig rearing facility, and the degree of odour exposure was assessed by measuring the frequency of odour-events by means of systematic field observations. Results showed that the degree of odour-annoyance as well as the frequency of somatic symptoms increased significantly with increasing odour-exposure, although their frequency was reduced relative to the first study, and mediated by annoyance. In both studies, perceived negative health was associated with increased symptom reports, however, results for old age were inconsistent. Response tendencies and biases were controlled. Environmental odours have been shown to be associated with somatic symptoms and, may, thus, be considered as a risk factor for health and wellbeing of exposed populations, especially for vulnerable subjects with perceived negative health. PMID:10507121
Approximately two-thirds of Duchenne muscular dystrophy (DMD) patients have a deletion in the dystrophin gene located at Xp21.1. Two PCR-based multiplex systems have been developed which detect 98% of deletions in affected males. Diagnosis of carrier females requires densitometry of PCR products following gel electrophoresis to calculate dosage of specific exons. We have developed a system in which fluorescently labelled PCR products are analysed using a GENESCANNER automated fragment analyser (ABI). Dosage is determined using computer-assisted laser densitometry (CALD). Recently, we diagnosed somatic mosaicism in the mother of an affected boy using this method. PCR analysis showed that the patient had a deletion that included exons 47-51 of his dystrophin gene. CALD analysis on the patient`s 36-year-old mother revealed a 29-34% reduction in the intensity of the bands corresponding to the deleted region of the gene rather than the 50% reduction normally seen in carrier females. A skin biopsy was obtain and monoclonal fibroblast colonies were tested by CALD for the deletion. Four of the twenty colonies screened were found to be deleted while the remaining colonies had two intact copies of the gene. We conclude that this patient is a somatic mosaic for DMD and that the mutation was the result of a post-zygotic event. This is the only case of somatic mosaicism detected among 800 women from 400 DMD families tested using CALD in our laboratory. At least one other case of possible somatic mosaicism has been reported but not confirmed. Germinal mosaicism is thought to occur in approximately 10% of mothers of sporadic DMD patients. Our findings indicate that somatic mosaicism is a much rarer condition among DMD carriers, thus suggesting that mitotic mutations in the dystrophin gene are more likely to occur later in embryogenesis after differentiation of the germline.
Sutherland, J.E.; Allingham-Hawkins, D.J.; MacKenzie, J. [Hospital for Sick Children, Toronto (Canada)] [and others
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
Poduri, Annapurna; Evrony, Gilad D; Cai, Xuyu; Walsh, Christopher A
Functional enuresis is a heterogeneous group of syndromes with different aetiology and pathophysiology. The aim was to identify\\u000a specific somatic correlates of enuresis non-invasively in child psychiatric patients after exclusion of neurologic and structural\\u000a forms of incontinence. One hundred sixty-seven consecutive children, aged 5 to 10 years with day and\\/or night wetting were\\u000a examined prospectively with: urinalysis and bacteriology; ultrasonography,
A. von Gontard; B. Benden; K. Mauer-Mucke; G. Lehmkuhl
The classical pluripotency factors Oct4, Klf4, Sox2, and Nanog are required for the maintenance of pluripotency and self-renewal of embryonic stem (ES) cells and can reprogram terminally differentiated cells into a pluripotent state. Alteration in the levels of these factors in ES cells will cause differentiation into different lineages, suggesting that they are critical determinants of cell fates. These factors show dynamic expression patterns during embryogenesis, in particular in the pluripotent or multipotent cells of an early stage embryo, implying that they are involved in the cell fate decision during early embryonic development. Functions and the underlying molecular mechanisms have been extensively studied for these factors in ES cells under cultured conditions. However, this does not mean that the results also hold true for intact embryos. In the review, I have summarized and discussed the findings on the functions and the underlying mechanisms of the classical pluripotency factors during early embryogenesis, in particular during germ layer formation.
Since the end of the American Civil War, unexplained symptoms in military personnel arising after a war or peace mission have frequently been described. The pattern of symptoms is highly similar for all of the various war syndromes although the conditions of each war or peace mission are widely different. Many somatic hypotheses have been formulated to explain these syndromes; a considerable proportion of them are already outdated. In the last few years much attention has been given to Gulf War Syndrome and to unexplained symptoms of military personnel who were sent to Cambodia, Rwanda, Burundi, Zaire, or the former Yugoslavia. In this review the symptoms of war syndromes will be considered in more detail and the suggested somatic explanations will be discussed. During the last decade the following somatic causes have been suggested as possible explanations for these symptoms: (persistent) infection, abnormal immune response, administration of multiple vaccinations within a short period of time, use of malaria chemoprophylaxis, neurological abnormalities, exposure to toxicological substances and environmental factors. The various investigations performed to study these hypotheses are discussed. The fact that bias regularly occurs in the course of these investigations is pointed out. For the future, a reliable investigation of a war syndrome should be a prospective multidisciplinary study and should distinguish between causative and sustaining factors. PMID:10886303
Soetekouw, P M; de Vries, M; van Bergen, L; Galama, J M; Keyser, A; Bleijenberg, G; van der Meer, J W
Summary The development of in vitro fertilization methods in plants, the characterization of developmental mutants, and the adaptation of molecular biology techniques to construct cDNA libraries from minute samples, all represent important recent technical break-throughs. They allow the study of fertilization and early embryogenesis at a molecular level and considerable improvement in the under-standing of higher plant reproduction can be
\\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
Denny Sakkas; Maria Lalioti; Hasan M. El-Fakahany; Emre Seli
\\u000a Errors in chromosome segregation occurring during human oogenesis and early embryogenesis are very common. Meiotic chromosome\\u000a development during oogenesis is subdivided into three distinct phases. The crucial events, including meiotic chromosome pairing\\u000a and recombination, take place from around 11 weeks until birth. Oogenesis is then arrested until ovulation, when the first\\u000a meiotic division takes place, with the second meiotic division
Glucose metabolism plays an essential role in the physiology and development of almost all living organisms. In the present study we investigated glucose metabolism during the embryogenesis of the hard tick Boophilus microplus. An increase in glucose and glycogen content during the embryonic development of B. microplus was detected and shown to be due to the high enzyme activity of both gluconeogenesis and glycolytic pathways. Glucose 6-phosphate (G-6P), formed by hexokinase, is driven mainly to pentose-phosphate pathway, producing fundamental substrates for cellular biosynthesis. We detected an increase in glucose 6-phosphate dehydrogenase and pyruvate kinase activities after embryo cellularization. Accumulation of key metabolites such as glycogen and glucose was monitored and revealed that glycogen content decreases from day 1 up to day 6, as the early events of embryogenesis take place, and increases after the formation of embryo cellular blastoderm on day 6. Glucose and guanine (a sub-product of amino acids degradation in arachnids) accumulate almost concomitantly. The activity of phosphoenolpyruvate carboxykinase was increased after embryo cellularization. Taken together these data indicate that glycogen and glucose, formed during B. microplus embryogenesis after blastoderm formation, are produced by intense gluconeogenesis. PMID:16904922
Moraes, Jorge; Galina, Antônio; Alvarenga, Patrícia H; Rezende, Gustavo Lazzaro; Masuda, Aoi; da Silva Vaz, Itabajara; Logullo, Carlos
Developmental events can be monitored at the cellular and molecular levels by using noninvasive imaging techniques. Among the biomolecules that might be targeted for imaging analysis, glycans occupy a privileged position by virtue of their primary location on the cell surface. We previously described a chemical method to image glycans during zebrafish larval development; however, we were unable to detect glycans during the first 24 hours of embryogenesis, a very dynamic period in development. Here we report an approach to the imaging of glycans that enables their visualization in the enveloping layer during the early stages of zebrafish embryogenesis. We microinjected embryos with azidosugars at the one-cell stage, allowed the zebrafish to develop, and detected the metabolically labeled glycans with copper-free click chemistry. Mucin-type O-glycans could be imaged as early as 7 hours postfertilization, during the gastrula stage of development. Additionally, we used a nonmetabolic approach to label sialylated glycans with an independent chemistry, enabling the simultaneous imaging of these two distinct classes of glycans. Imaging analysis of glycan trafficking revealed dramatic reorganization of glycans on the second time scale, including rapid migration to the cleavage furrow of mitotic cells. These studies yield insight into the biosynthesis and dynamics of glycans in the enveloping layer during embryogenesis and provide a platform for imaging other biomolecular targets by microinjection of appropriately functionalized biosynthetic precursors.
Baskin, Jeremy M.; Dehnert, Karen W.; Laughlin, Scott T.; Amacher, Sharon L.; Bertozzi, Carolyn R.
Stress-induced plant cell reprogramming involves changes in global genome organization, being the epigenetic modifications key factors in the regulation of genome flexibility. DNA methylation, accomplished by DNA methyltransferases, constitutes a prominent epigenetic modification of the chromatin fibre which is locked in a transcriptionally inactive conformation. Changes in DNA methylation accompany the reorganization of the nuclear architecture during plant cell differentiation and proliferation. After a stress treatment, in vitro-cultured microspores are reprogrammed and change their gametophytic developmental pathway towards embryogenesis, the process constituting a useful system of reprogramming in isolated cells for applied and basic research. Gene expression driven by developmental and stress cues often depends on DNA methylation; however, global DNA methylation and genome-wide expression patterns relationship is still poorly understood. In this work, the dynamics of DNA methylation patterns in relation to nuclear architecture and the expression of BnMET1a-like DNA methyltransferase genes have been analysed during pollen development and pollen reprogramming to embryogenesis in Brassica napus L. by a multidisciplinary approach. Results showed an epigenetic reprogramming after microspore embryogenesisinduction which involved a decrease of global DNA methylation and its nuclear redistribution with the change of developmental programme and the activation of cell proliferation, while DNA methylation increases with pollen and embryo differentiation in a cell-type-specific manner. Changes in the presence, abundance, and distribution of BnMET1a-like transcripts highly correlated with variations in DNA methylation. Mature zygotic and pollen embryos presented analogous patterns of DNA methylation and MET1a-like expression, providing new evidence of the similarities between both developmental embryogenic programmes.
Somatic cell reprogramming is achieved by four reprogramming transcription factors (RTFs), Oct3/4, Sox2, Klf4, and c-Myc. However, in addition to the induction of pluripotent cells, these RTFs also generate pseudo-pluripotent cells, which do not show Nanog promoter activity. Therefore, it should be possible to fine-tune the RTFs to produce only fully pluripotent cells. For this study, a tagging system was developed to sort induced pluripotent stem (iPS) cells according to the expression levels of each of the four RTFs. Using this system, the most effective ratio (Oct3/4-high, Sox2-low, Klf4-high, c-Myc-high) of the RTFs was 88 times more efficient at producing iPS cells than the worst effective ratio (Oct3/4-low, Sox2-high, Klf4-low, c-Myc-low). Among the various RTF combinations, Oct3/4-high and Sox2-low produced the most efficient results. To investigate the molecular basis, microarray analysis was performed on iPS cells generated under high (Oct3/4-high and Sox2-low) and low (Oct3/4-low and Sox2-high) efficiency reprogramming conditions. Pathway analysis revealed that the G protein-coupled receptor (GPCR) pathway was up-regulated significantly under the high efficiency condition and treatment with the chemokine, C-C motif ligand 2, a member of the GPCR family, enhanced somatic cell reprogramming 12.3 times. Furthermore, data from the analysis of the signature gene expression profiles of mouse embryonic fibroblasts at 2 days after RTF infection revealed that the genetic modifier, Whsc1l1 (variant 1), also improved the efficiency of somatic cell reprogramming. Finally, comparison of the overall gene expression profiles between the high and low efficiency conditions will provide novel insights into mechanisms underlying somatic cell reprogramming.
Summary Conditions favourable to embryogenesis from isolated microspores of Brassica rapa L. ssp. oleifera (canola quality) were identified. A population with enhanced responsiveness for microspore embryogenesis (C200) was synthesized by crossing individual plants showing microspore embryogenic potential. For optimal microspore embryogenesis, buds (2–3mm in length, containing mid-late uninucieate microspores) were collected from older plants (2 months old) and microspores isolated and
Cell suspension cultures were established from immature cotyledon derived calli from drought tolerant legume horsegram [Macrotyloma uniflorum (Lam.) Verdc.]. Embryogenic callus could be originated from cut slices of the immature cotyledons on MS solid medium [Murashige, T. Skoog, K., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473–497] augmented with 1.0?M zeatin
Shamsudeen Varisai Mohamed; Jih-Min Sung; Toong-Long Jeng; Chang-Sheng Wang
Summary Tissue cultures ofTriticum aestivum L. (wheat) initiated from young inflorescences and immature embryos possessed the potential for regeneration of whole plants. Both a friable and a compact type of callus were produced on Murashige and Skoog's medium with 2 mg\\/l 2,4-dichlorophenoxyacetic acid. The friable callus contained meristematic centers in which the peripheral cells ceased dividing, elongated, and could be
Taverniera cuneifolia (Roth) Arn. or Indian licorice is considered to be a substitute for Glycyrrhiza glabra L. owing to an equivalent content of glycyrrhizic acid (GA). GA recognized as the main active ingredient of T. cuneifolia, GA imparts several medicinal properties to these plants. However, research on this plant is scanty with no published record\\u000a on tissue culture studies. Present
Cell suspension cultures, which retained embryogenic potential for almost 2 years, were established from young, expanding, juvenile leaves of a mature Thevetia peruviana L. tree. Calli were obtained by culturing young leaf discs on MS medium supplemented with 2 mg\\/L 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 0.1 mg\\/L kinetin. Suspension cultures were initiated by transfer of calli to liquid medium
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
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.
It had been long assumed that almost all insertions of mobile DNA elements occurred during germ-cell development rather than in somatic-cell development, but solid evidence for transposition in somatic cells is now accumulating. To add to this evidence, a recent paper in Mobile DNA reports the somatic transposition of a site-specific retrotransposon, R2, into its insertion site in 28S ribosomal DNA in Drosophila embryos. PMID:21958341
Symptoms of somatization were investigated in pediatric patients with recurrent abdominal pain (RAP) and comparison groups of patients with organic etiology for abdominal pain and well patients. Somatization scores were higher in RAP patients than well patients at the clinic visit, and higher than in either well patients or organic patients at a 3- month followup. Higher somatization scores in
Problems in establishing a therapeutic alliance make somatizing patients poor candidates for psychotherapy. A logical analysis is presented of the conspiracy of silence between the somatizing patient, the medical doctor, and the health insurance industry regarding the psychosocial factors contributing to somatization. Alternatives are sought to repeated biomedical tests and therapies that are clinically unproductive and iatrogenic. Two psychophysiological pathways
Insulin-like growth factors-I and-II (IGF-I and IGF-II) play important roles in growth and development of mammals. Toll-like receptors (TLRs) are pattern recognition molecules that orchestrate the induction of early innate immune response by recognition of specific sequences. Evidence is growing that suggests a relationship between growth and immune function. The objective of the study was to examine changes in gene expression of IGF-I, IGF-II, TLR3, and TLR5 during embryogenesis and early larval development in hybrid (channel catfishxblue catfish) and channel catfish. Egg samples were taken pre- and post-fertilization; embryos were collected at two stages of embryogenesis, at hatch, and at swim-up. All genes were detected in unfertilized catfish eggs. Expression levels of TLR5 and IGF-I mRNA in channel catfish and expression levels of TLR3, IGF-I, and IGF-II mRNA in hybrids increased over time (P<0.01). Effect of time was not significant for expression of IGF-II or TLR3 mRNA in channel catfish and for TLR5 mRNA in hybrid catfish. Results of this study suggest growth (IGF-I and IGF-II) and immune (TLR3 and TLR5) associated genes could be functional and play important roles during embryogenesis and early development of hybrid and channel catfish. PMID:15882955
Peterson, Brian C; Bosworth, Brian G; Bilodeau, A Lelania
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.
McGee, Sean P.; Cooper, Ellen M.; Stapleton, Heather M.
During fruit fly embryogenesis, there are several morphogenetic events in which sheets of epithelial cells expand, contract and bend due to coordinated intra- and intercellular forces. This tissue-level reshaping is accompanied by changes in the shape and arrangement of individual cells -- changes that can be measured quantitatively and dynamically using modern live-cell imaging techniques. Such data sets represent rich targets for computational modeling of self-organization; however, reproducing the observed cell- and tissue-level reshaping is not enough. The inverse problem of using cell shape changes to determine cell-level forces is ill-posed -- yielding non-unique solutions that cannot discriminate between active changes in cell shape and passive deformation. These non-unique solutions can be tested experimentally using in vivo laser-microsurgery -- i.e., cutting a targeted region of an epithelium and carefully tracking the temporal and spatial dependence of the subsequent strain relaxation. This technique uses a variety of incisions (hole, line or closed curve) to probe different aspects of epithelial mechanics: the local mesoscopic strain; the distribution of intracellular forces; changes in the cell-level power-law rheology; and the question of active versus passive deformation. I will discuss my group's work using laser-microsurgery to investigate two morphogenetic events in fruit fly embryogenesis: germband retraction and dorsal closure. In both cases, we find a substantial active mechanical role for the amnioserosa -- an epithelium that undergoes apoptosis near the end of embryogenesis and makes no part of the fly larva -- in reshaping an adjacent epithelium that becomes the larval epidermis. In these examples, self-organization of the fly embryo relies not only on self-organization of individual tissues, but also on the mechanical interactions between tissues.
Six identical bioreactors were constructed and built at the Agricultural University of Norway to provide optimal conditions for plant cell regeneration from cells into somatic embryos (‘clonal or somatic seeds’). This was made possible through cooperation in COST87 by a European network in a working group on regeneration from plant cell cultures. The bioreactor design provides gentle stirring through a
Anne Kathrine Hvoslef-Eide; Odd Arild S. Olsen; Ragnhild Lyngved; Cristel Munster; Petter H. Heyerdahl
Six identical bioreactors were constructed and built at the Agricultural University of Norway to provide optimal conditions for plant cell regeneration from cells into somatic embryos (“clonal or somatic seeds”). This was made possible through cooperation in COST87 by a European network in a working group on regeneration from plant cell cultures. The bioreactor design provides gentle stirring through a
Somatic education offers the promise of freer and easier movement and enhanced body awareness through gentle exercises and\\/or body manipulation. This column explores Web resources that offer useful information for learning more about somatic education practices including the Alexander Technique, the Feldenkrais Method, and a few other key practices.
In this report 50 subjects with multiple sclerosis are compared to 50 subjects with multiple personality disorder. The multiple sclerosis patients endorsed an average (1 3.0 somatic symptoms on structuredinterview, the multiple personality subjects an average of 14.5. The somatic symptoms characteristic of neurological illness were trouble walking, paralysis, and muscle weakness. Those characteristic of psychiatric illness were genitourinary and
Colin A. Ross; Geri Anderson; Anthony Auty; Judy Todd; Cohn A. Ross
Background In our research we examined the frequency of somatic symptoms among bereaved (N?=?185) and non-bereaved men and women in a national representative sample (N?=?4041) and investigated the possible mediating factors between bereavement status and somatic symptoms. Methods Somatic symptoms were measured by the Patient Health Questionnaire (PHQ-15), anxiety with a four-point anxiety rating scale, and depression with a nine-item shortened version of the Beck Depression Inventory. Results Among the bereaved, somatic symptoms proved to be significantly more frequent in both genders when compared to the non-bereaved, as did anxiety and depression. On the multivariate level, the results show that both anxiety and depression proved to be a mediator between somatic symptoms and bereavement. The effect sizes indicated that for both genders, anxiety was a stronger predictor of somatic symptoms than depression. Conclusions The results of our research indicate that somatic symptoms accompanying bereavement are not direct consequences of this state but they can be traced back to the associated anxiety and depression. These results draw attention to the need to recognize anxiety and depression looming in the background of somatic complaints in bereavement and to the importance of the dissemination of related information.
BACKGROUND: The consecutive acquisition of genetic alterations characterizes neoplastic processes. As a consequence of these alterations, molecular interactions are reprogrammed in the context of highly connected and regulated cellular networks. The recent identification of the collection of somatically mutated genes in breast tumors (breast cancer somatic \\
Pilar Hernández; Xavier Solé; Joan Valls; Víctor Moreno; Gabriel Capellá; Ander Urruticoechea; Miguel Angel Pujana
The principle objective of this research programme, to analyse chemical induction of somatic recombination and related endpoints, i.e., mobilization of transposing elements and gene amplification, has been approached by means of several assay systems. These have included Drosophila, Saccharomyces and mammalian cell cultures. 6.1. Screening assays for mitotic recombination. A large number of chemicals have been investigated in the three Drosophila assay systems employed--the multiple wing hair/flare wing spot system developed by Graf et al., 1984, the white-ivory system developed by Green et al., 1986 and the white/white+ eye spot assay developed by Vogel (Vogel and Nivard, 1993). Particularly the screening of 181 chemicals, covering a wide array of chemical classes, by the last mentioned assay has shown that measurement of somatic recombination in Drosophila constitutes a sensitive and efficient short-term test which shows a remarkably good correlation with the agent score of 83 short-term tests analysed by ICPEMC (Mendelsohn et al., 1992; Table 2) as well as the assay performance in international collaborative programmes measuring carcinogen/non-carcinogens (de Serres and Ashby, 1981; Ashby et al., 1985, 1988). Also the wing spot assay has gained wide international recognition as a similarly sensitive test. These two assay systems in Drosophila measure both intrachromosomal events and interchromosomal recombination. The white-ivory system on the other hand is based on the loss of a tandem duplication in the white locus, the mechanism of which is less known, but probably involves intrachromosomal recombination. The difference in the mechanism between this assay and the former two was indicated by the lack of response to methotrexate in the white-ivory assay, while this compound was strongly recombinogenic in both the wing spot and white/white+ assays. The use of different strains of Drosophila with the white/white+ assay demonstrated the importance of the background genotype for the outcome of the test. Up to a 60-fold variation was found between the different genotypes in the response to procarcinogens, evidently dependent on differences in the metabolic activation of procarcinogens. In 1989 Schiestl presented results on intrachromosomal recombination in the strain RS112 of Saccharomyces, which indicated a capability to detect a range of chemical carcinogens, which gave negative results in Ames Salmonella assay. Such a test system, which could identify a larger range of potential carcinogens than conventional short-term tests evidently would be of great value and it therefore seemed of importance to follow up the observations by Schiestl. However, studies within this programme on the same strain of Saccharomyces, as well as the strains D7 (measuring intragenic recombination, intergenic recombination, and point mutation) and JD1 (measuring intragenic recombination at two loci) could not support the observations and interpretation by Schiestl (1989). The Drosophila white-ivory system, which presumably responds primarily by intrachromosomal recombination, did not give positive results with these Salmonella-negative agents either. One system to measure mitotic recombination in mammalian cell cultures was developed in the present programme. It was based on heterozygous mutations in both alleles of the adenosine deaminase gene (ADA). The system selects for proficient recombinants generated by the deficient cells. So far only pilot experiments, indicating that this experimental system operates as planned, have been performed. 6.2 Mechanisms of mitotic recombination The induction of mosaic spots in the wing spot and the white/white+ assays is predominantly dependent on interchromosomal recombination. This is evident from the fact that heterozygous inversions reduce the frequency of spots. A relationship between the length of inversions and the reduction of spots was demonstrated in the white/white+ assay--the long inversion ln(l)sc4L PMID:8692194
Ramel, C; Cederberg, H; Magnusson, J; Vogel, E; Natarajan, A T; Mullender, L H; Nivard, J M; Parry, J M; Leyson, A; Comendador, M A; Sierra, L M; Ferreiro, J A; Consuegra, S
In this study we examine whether a somatic cell, once returned to a pluripotent state, gains the ability to reprogram other somatic cells. We reprogrammed mouse embryonic fibroblasts by viral induction of oct4, sox2, c-myc, and klf-4 genes. Upon fusion of the resulting iPS cells with somatic cells harboring an Oct4-GFP transgene we observed, GFP expression along with activation of Oct4 from the somatic genome, expression of key pluripotency genes, and positive immunostaining for Oct4, SSEA-1, and alkaline phosphatase. The iPS-somatic hybrids had the ability to differentiate into cell types indicative of the three germ layers and were able to localize to the inner cell mass of aggregated embryos. Furthermore, ntES cells were used as fusion partners to generate hybrids, which were also confirmed to be reprogrammed to a pluripotent state. These results demonstrate that once a somatic cell nucleus is reprogrammed, it acquires the capacity and potency to reprogram other somatic cells by cell fusion and shares this functional property with normal embryonic stem (ES) cells. PMID:19637940
Formation of a properly branched vascular system during embryogenesis is crucial for embryo survival. Here we review the regulation of the morphogenesis of the arterial and venous system during embryogenesis. We show that in addition to deterministic patterning mechanisms and plasticity of endothelial cells, arterial-venous differentiation and branching morphogenesis involves a prominent role for blood flow. Based on in vivo
V. Fleury; A. Pries; P. Corvol; A. Eichmann; R. S. Reneman
Isolated microspore culture experiments were carried out to induce microspore embryogenesis in Chamomilla recutita, Solidago virgaurea, Sanvitalia procumbens of the Asteracea, and Valeriana officinalis of the Valerianaceae. The Asteracea is one the largest plant families of commercial significance for medicinal, aromatic, food and ornamental\\u000a use. Availability of protocols for an efficient production of doubled haploids via microspore embryogenesis would facilitate
That the yolk proteins (YPs), or vitellins, stored in the oocytes of insects are a nutritional store for subsequent embryogenesis has long been assumed. Exhaustive data base searching programs revealed highly significant sequence similarity between the three YPs of Drosophila melanogaster and part of the triacylglycerol lipase of the domestic pig. Based upon time of degradation of YPs during embryogenesis,
Mary Bownes; Alan Shirras; Mairead Blair; John Collins; Andrew Coulson
Bone morphogenetic protein 15 (BMP15) belongs to an unusual subgroup of the transforming growth factor ? (TGF?) superfamily of signaling ligands as it lacks a key cysteine residue in the mature region required for proper intermolecular dimerization. Naturally occurring BMP15 mutation leads to early ovarian failure in humans, and BMP15 has been shown to activate the Smad1/5/8 pathway in that context. Despite its important role in germ cell specification, the embryological function of BMP15 remains unknown. Surprisingly, we find that during early Xenopus embryogenesis BMP15 acts solely as an inhibitor of the Smad1/5/8 pathway and the Wnt pathway. BMP15 gain-of-function leads to embryos with secondary ectopic heads and to direct neural induction in intact explants. BMP15 inhibits BMP4-mediated epidermal induction in dissociated explants. BMP15 strongly inhibits BRE response induced by BMP4 and blocks phosphorylation and activation of Smad1/5/8 MH2-domain. Mechanistically, BMP15 protein specifically interacts with BMP4 protein, suggesting inhibition upstream of receptor binding. Loss-of-function experiments using morpholinos or a naturally occurring human BMP15 dominant-negative mutant (BMP15-Y235C) leads to embryos lacking head. BMP15-Y235C also eliminates the inhibitory activity of BMP15 on BRE (BMP-responsive element). Finally, we show that BMP15 inhibits the canonical branch of the Wnt pathway, upstream of ?-catenin. We, thus, demonstrate that BMP15 is necessary and sufficient for the specification of dorso-anterior structures and highlight novel mechanisms of BMP15 function that strongly suggest a reinterpretation of its function in ovaries specially for ovarian failure.
Background Cell-fate specification and tissue differentiation during development are largely achieved by the regulation of gene transcription. Results As a first step to creating a comprehensive atlas of gene-expression patterns during Drosophila embryogenesis, we examined 2,179 genes by in situ hybridization to fixed Drosophila embryos. Of the genes assayed, 63.7% displayed dynamic expression patterns that were documented with 25,690 digital photomicrographs of individual embryos. The photomicrographs were annotated using controlled vocabularies for anatomical structures that are organized into a developmental hierarchy. We also generated a detailed time course of gene expression during embryogenesis using microarrays to provide an independent corroboration of the in situ hybridization results. All image, annotation and microarray data are stored in publicly available database. We found that the RNA transcripts of about 1% of genes show clear subcellular localization. Nearly all the annotated expression patterns are distinct. We present an approach for organizing the data by hierarchical clustering of annotation terms that allows us to group tissues that express similar sets of genes as well as genes displaying similar expression patterns. Conclusions Analyzing gene-expression patterns by in situ hybridization to whole-mount embryos provides an extremely rich dataset that can be used to identify genes involved in developmental processes that have been missed by traditional genetic analysis. Systematic analysis of rigorously annotated patterns of gene expression will complement and extend the types of analyses carried out using expression microarrays.
Epidemiological studies have correlated arsenic exposure in drinking water with adverse developmental outcomes such as stillbirths, spontaneous abortions, neonatal mortality, low birth weight, delays in the use of musculature, and altered locomotor activity. Killifish (Fundulus heteroclitus) were used as a model to help to determine the mechanisms by which arsenic could impact development. Killifish embryos were exposed to three different sodium arsenite concentrations and were collected at 32 h post-fertilization (hpf), 42 hpf, 168 hpf, or < 24 h post-hatch. A killifish oligo microarray was developed and used to examine gene expression changes between control and 25-ppm arsenic-exposed hatchlings. With artificial neural network analysis of the transcriptomic data, accurate prediction of each group (control vs. arsenic-exposed embryos) was obtained using a small subset of only 332 genes. The genes differentially expressed include those involved in cell cycle, development, ubiquitination, and the musculature. Several of the genes involved in cell cycle regulation and muscle formation, such as fetuin B, cyclin D–binding protein 1, and CapZ, were differentially expressed in the embryos in a time- and dose-dependent manner. Examining muscle structure in the hatchlings showed that arsenic exposure during embryogenesis significantly reduces the average muscle fiber size, which is coupled with a significant 2.1- and 1.6-fold upregulation of skeletal myosin light and heavy chains, respectively. These findings collectively indicate that arsenic exposure during embryogenesis can initiate molecular changes that appear to lead to aberrant muscle formation.
Gaworecki, Kristen M.; Chapman, Robert W.; Neely, Marion G.; D'Amico, Angela R.; Bain, Lisa J.
Recently, radiation-induced bystander effects (RIBE) have been studied in mouse models in vivo, which clearly demonstrated bystander effects among somatic cells. However, there is currently no evidence for RIBE between somatic cells and germ cells in animal models in vivo. In the current study, the model animal Caenorhabditis elegans was used to investigate the bystander signaling from somatic cells to germ cells, as well as underlying mechanisms. C. elegans body size allows for precise microbeam irradiation and the abundant mutant strains for genetic dissection relative to currently adopted mouse models make it ideal for such analysis. Our results showed that irradiation of posterior pharynx bulbs and tails of C. elegans enhanced the level of germ cell apoptosis in bystander gonads. The irradiation of posterior pharynx bulbs also increased the level of DNA damage in bystander germ cells and genomic instability in the F1 progeny of irradiated worms, suggesting a potential carcinogenic risk in progeny even only somatic cells of parents are exposed to ionizing radiation (IR). It was also shown that DNA damage-induced germ cell death machinery and MAPK signaling pathways were both involved in the induction of germ cell apoptosis by microbeam induced bystander signaling, indicating a complex cooperation among multiple signaling pathways for bystander effects from somatic cells to germ cells. PMID:23931723
We examined the distribution of the somatic subtypes of histone H1 and the variant subtype, H1(0), and their encoding mRNAs during oogenesis and early embryogenesis in the mouse. As detected using immunocytochemistry, somatic H1 was present in the nuclei of oocytes of 18-day embryos. Following birth, however, somatic H1 became less abundant in both growing and non-growing oocytes, beginning as early as 4 days of age in the growing oocytes, and was scarcely detectable by 19 days. Together with previous results, this defines a period of time when somatic H1 is depleted in oocytes, namely, from shortly after birth when the oocytes are at prophase I until the 4-cell stage following fertilization. At the stages when somatic H1 was undetectable, oocyte nuclei could be stained using an antibody raised against histone H1(0), which suggests that this may be a major linker histone in these cells. In contrast to the post-natal loss of somatic H1 protein, mRNAs encoding four (H1a, H1b, H1d, H1e) of the five somatic subtypes were present, as detected using RT-PCR in growing oocytes of 9-day pups, and all five subtypes including H1c were present in fully grown oocytes of adults. All five subtypes were also present in embryos, both before and after activation of the embryonic genome. mRNA encoding H1(0) was also detected in oocytes and early embryos. Whole-mount in situ hybridization using cloned H1c and H1e cDNAs revealed that the mRNAs were present in the cytoplasm of oocytes and 1-cell embryos, in contrast to the sea urchin early embryo where they are sequestered in the cell nucleus. We suggest that, as in many somatic cell types, the chromatin of mouse oocytes becomes depleted of somatic H1 and relatively enriched in histone H1(0) postnatally, and that somatic H1 is reassembled onto chromatin in cleavage-stage embryos. The post-natal loss of somatic H1 appears to be regulated post-transcriptionally by a mechanism not involving nuclear localization. PMID:9067599
The authors studied the effects of caffeine withdrawal on 14 subjects at baseline and during a 4-day period of abstinence from caffeine. They studied the results from quantitative electroencephalograms performed on these subjects and gauged any changes that may have been evoked during this withdrawal period. The participants were also evaluated for the occurrence of somatic dysfunctions. Examinations for the presence of somatic dysfunctions were performed on the participants before caffeine cessation and on Days 1, 2 and 4 of abstinence. Results showed that the number of somatic dysfunctions increased significantly during the process of caffeine withdrawal. PMID:9284612
Evolution is based on genetic variability and subsequent phenotypic selection. Mechanisms that modulate the rate of mutation according to environmental cues, and thus control the balance between genetic stability and flexibility, might provide a distinct evolutionary advantage. Stress-induced mutations stimulated by unfavorable environments, and possible mechanisms for their induction, have been described for several organisms, but research in this area has mainly focused on microorganisms. We have analyzed the influence of adverse environmental conditions on the genetic stability of the higher plant Arabidopsis thaliana. Here we show that a biotic stress factor-attack by the oomycete pathogen Peronospora parasitica-can stimulate somatic recombination in Arabidopsis. The same effect was observed when plant pathogen-defense mechanisms were activated by the chemicals 2,6-dichloroisonicotinic acid (INA) or benzothiadiazole (BTH), or by a mutation (cim3). Together with previous studies of recombination induced by abiotic factors, these findings suggest that increased somatic recombination is a general stress response in plants. The increased genetic flexibility might facilitate evolutionary adaptation of plant populations to stressful environments. PMID:11836502
Lucht, Jan M; Mauch-Mani, Brigitte; Steiner, Henry-York; Metraux, Jean-Pierre; Ryals, John; Hohn, Barbara
A study was made of a series of 139 outpatients referred by the medical and surgical services of a general hospital for evaluation by the psychiatry unit. In accordance with established criteria, this population was divided into somatizers (56) and non-somatizers (75), and the socio-demographic and clinical characteristics of both groups were comparatively analyzed. The results show that the group of somatizers was younger, had more histrionic personality traits and more stress factors related with alterations in interpersonal relationships or death or disease of relatives. It is emphasized that somatization is poorly known by psychiatrists--whose diagnostic criteria practically omit these aspects--and by other physicians, in spite of its importance and frequency. PMID:3673644
de León, J; Saiz-Ruiz, J; Chinchilla, A; Morales, P
The volume was written to fill a knowledge gap by providing busy primary care practitioners with practical, state-of-the-art assessment, treatment, and management techniques for somatization disorder. It is intended to aid clinicians in more effectively r...
Microelectrophysiological studies have been made on the development of neuronal activity in the structures of the striatal complex 17--21-day chick embryos. The density of spontaneously active neurones, their frequency parameters, the pattern of impulse activity and presentation of synaptic inputs for different modalities were investigated. The data obtained indicate the existence of significant heterochrony in the onset of neuronal activity in different parts of the telencephalon: the development of neuronal systems in phylogenetically more ancient structures, i.e. archi- and paliostriatum--takes place earlier than in younger formations--neo- and hyperstriatum. It is concluded that at final stages of embryogenesis the structure of neuronal activity of motor analyser undergoes deep functional changes which provide for the necessary level of plasticity of functional brain systems accounting for adaptive changes in the motor activity during embryonic development. PMID:7405442
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.
This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer (cloning)," last published in Fertil Steril 2000;74:873-6. PMID:22795681
Rhythmical contractile activity of amnion accompanies development of reptiles and birds in the course of a large part of embryogenesis.\\u000a These rhythmical contractions are myogenic and spontaneous. The strength, frequency, and character of the amnion contractions\\u000a change in embryogenesis in a regular way. This type of rhythmical activity is sensitive to many neurotransmitters and external\\u000a factors. Features of similarity and
Using callus derived from immature embryos, regeneration of viable plants was obtained in soybean (Glycine max (L.) Merr.). Depending on the composition of the medium, regeneration occurred via embryogenesis or via organogenesis. Embryogenesis resulted when embryos were plated on Murashige and Skoog (MS) medium containing 43 µM a-naphthaleneacetic acid. In work with the cultivar Williams 82, the addition of 5.0
Mitogen-activated protein kinase (MAPK) is activated by MAPK kinase (MAPKK) in a variety of signaling pathways. This kinase cascade has been shown to function in cell proliferation and differentiation, but its role in early vertebrate development remains to be investigated. During early vertebrate embryogenesis, the induction and patterning of mesoderm are thought to be determined by signals from intercellular factors such as members of the fibroblast growth factor (FGF) family and members of the transforming growth factor-beta family. Here we show that the microinjection of either mRNA encoding a constitutively active mutant of MAPKK or mRNA encoding a constitutively active form of STE11, a MAPKK kinase, leads to the induction of mesoderm in ectodermal explants from Xenopus embryos. Moreover, the expression of MAPK phosphatase-1 (MKP-1, also called CL100) blocks the growth factor-stimulated mesoderm induction. Furthermore, injection of CL100 mRNA into two-cell stage embryos causes severe defects in gastrulation and posterior development. The effects induced by CL100 can be rescued by co-injection of wild-type MAPK mRNA. Thus, the MAPK cascade may play a crucial role in early vertebrate embryogenesis, especially during mesoderm induction. Images
Gotoh, Y; Masuyama, N; Suzuki, A; Ueno, N; Nishida, E
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.
Anderson, Thomas T. (Downers Grove, IL); Roop, Conard J. (Lockport, IL); Schmidt, Kenneth J. (Midlothian, IL); Brewer, John (Oak Lawn, IL)
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.
Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.
Despite the frequent association between anxiety and somatization, the role of somatic anxiety-a tendency to experience somatic sensations, when anxious-in relationship to persistent somatic complaints has not been addressed previously. This study assessed the predictive role of internalizing psychopathology (anxiety, posttraumatic stress, depression) and somatic anxiety for somatic complaints over a 1-year period in a community sample of urban youth. The Social and Health Assessment, a self-report survey, was administered to 2,524 (mean age = 12.8, 54 % female) American urban adolescents in two consecutive years. There was significant continuity of somatic complaints over 1 year. Girls reported higher levels of somatic complaints and somatic anxiety than boys. All types of internalizing psychopathology significantly predicted somatic complaints over time. Somatic anxiety was associated with somatic complaints over and above the role of internalizing symptoms. Internalizing psychopathology and somatic anxiety should both be considered in the assessment and treatment of youth with persistent somatic complaints. PMID:23744452
Pluripotent cells of the early preimplantation embryo originate all types of somatic cell and germ cells of the adult organism. Permanent pluripotent cell lines (ES and EG cells) that were derived from an inner cell mass of blastocysts and primordial germ cells have a high proliferative potential and ability to differentiate in vitro into a wide variety of somatic and extraembryonic tissues as well as germ cells and to contribute to different organs of chimeric animals. In some cases pluripotent cells and primordial germ cells can generate teratomas, teratocarsinomas and some kinds of seminomas as the results of damages of differentiation programme of these cells. Experimental teratomas which formed after transplantation of undifferentiated ES and EG cells into immunocompromiced mice may provide a unique opportunity to study pluripotent cell specification and to develop novel approaches in carcinogenesis investigations. Research of signaling and metabolic pathways regulating the pluripotent cell maintenance and their multilineage differentiation are essential to search molecular targets to eliminate undifferentiated cells in tumors. Analysis of interactions between pluripotent cells and differentiated cells of the recipient animals, identification of the factors that may drive differentiation ES and EG cells in vivo contribute in understanding the mechanisms involved in the determination of cell fate during normal development and tumorigenesis. These data are important for development of effective and safe stem cell based technologies for prospective clinical treatment. PMID:22997845
Transposable elements (TEs) are abundant in the human genome, and some are capable of generating new insertions through RNA intermediates. In cancer, the disruption of cellular mechanisms that normally suppress TE activity may facilitate mutagenic retrotranspositions. We performed single-nucleotide resolution analysis of TE insertions in 43 high-coverage whole-genome sequencing data sets from five cancer types. We identified 194 high-confidence somatic TE insertions, as well as thousands of polymorphic TE insertions in matched normal genomes. Somatic insertions were present in epithelial tumors but not in blood or brain cancers. Somatic L1 insertions tend to occur in genes that are commonly mutated in cancer, disrupt the expression of the target genes, and are biased toward regions of cancer-specific DNA hypomethylation, highlighting their potential impact in tumorigenesis. PMID:22745252
Lee, Eunjung; Iskow, Rebecca; Yang, Lixing; Gokcumen, Omer; Haseley, Psalm; Luquette, Lovelace J; Lohr, Jens G; Harris, Christopher C; Ding, Li; Wilson, Richard K; Wheeler, David A; Gibbs, Richard A; Kucherlapati, Raju; Lee, Charles; Kharchenko, Peter V; Park, Peter J
The patterns of Glut1 and Glut3 glucose transporter protein and mRNA expression were assessed during embryogenesis of chicken brain and skeletal muscle, Glut4 protein levels were also evaluated in skeletal muscle and heart, and Glut1 was examined in the developing heart and liver. Glut1 protein expression was detectable throughout brain ontogeny but was highest during early development. Glut1 mRNA levels in the brain remained very high throughout development. Glut3 protein was highest very early and very late and mRNA was highest during the last half of development. In embryonic skeletal muscle, the levels of Glut1 and Glut3 proteins and mRNA were highest very early, and declined severely by mid-development. Glut1 protein and mRNA in the heart also peaked early and then decreased steadily. Although Glut1 mRNA levels were consistently high in the embryonic liver, Glut1 protein expression was not detected. These results suggest that (1) Glut1 is developmentally regulated in chick brain, skeletal muscle, and heart, (2) Glut1 mRNA is present in liver but does not appear to be translated, (3) Glut3 in brain increases developmentally but is virtually absent in muscle, and (4) Glut4 protein and mRNA appear to be absent from chick heart and skeletal muscle. PMID:11361097
Carver, F M; Shibley, I A; Pennington, J S; Pennington, S N
Er71 mutant embryos are nonviable and lack hematopoietic and endothelial lineages. To further define the functional role for ER71 in cell lineage decisions, we generated genetically modified mouse models. We engineered an Er71-EYFP transgenic mouse model by fusing the 3.9 kb Er71 promoter to the EYFP reporter gene. Using FACS and transcriptional profiling, we examined the EYFP(+) population of cells in Er71 mutant and wild-type littermates. In the absence of ER71, we observed an increase in the number of EYFP-expressing cells, increased expression of the cardiac molecular program and decreased expression of the hemato-endothelial program, as compared with wild-type littermate controls. We also generated a novel Er71-Cre transgenic mouse model using the same 3.9 kb Er71 promoter. Genetic fate-mapping studies revealed that the ER71-expressing cells give rise to the hematopoietic and endothelial lineages in the wild-type background. In the absence of ER71, these cell populations contributed to alternative mesodermal lineages, including the cardiac lineage. To extend these analyses, we used an inducible embryonic stem/embryoid body system and observed that ER71 overexpression repressed cardiogenesis. Together, these studies identify ER71 as a critical regulator of mesodermal fate decisions that acts to specify the hematopoietic and endothelial lineages at the expense of cardiac lineages. This enhances our understanding of the mechanisms that govern mesodermal fate decisions early during embryogenesis. PMID:21989919
Rasmussen, Tara L; Kweon, Junghun; Diekmann, Mackenzie A; Belema-Bedada, Fikru; Song, Qingfeng; Bowlin, Kathy; Shi, Xiaozhong; Ferdous, Anwarul; Li, Tongbin; Kyba, Michael; Metzger, Joseph M; Koyano-Nakagawa, Naoko; Garry, Daniel J
Gametogenesis fertilization and early embryogenesis are crucial periods for normal development afterwards In past three decades many experiments have been conducted in space and in simulated weightlessness induced by clinostats to elucidate the issue Different animal species including Drosophila wasp shrimp fish amphibian mouse rats etc have been used for the study Oogenesis and spermatogenesis are affected by microgravity in different ways Some researches found that microgravity condition perturbed the process of oogenesis in many species A significant increased frequency of chromosomal non-disjunction was found in Drosophila females resulting the loss of chromosomes during meiosis and inhibition of cell division Studies on wasp showed a decreased hatchability and accumulation of unhatched eggs when the insects were exposed to spaceflight at different stages of oogenesis For experiments conducted on vertebrate animal models the results are somehow different however Microgravity has no significant effect for fish Medaka etc amphibian South African clawed toad Xenopus laevis or mammals mouse Spermatogenesis on the other hand is more significantly affected by microgravity condition Some researches indicated sperm are sensitive to changes in gravitational force and this sensitivity affects the ability of sperm to fertilize eggs Sperm swim with higher velocity in microgravity which is coupled with altered protein phosphorylation level in sperm under microgravity condition Microgravity also induced activation of the
We have recently presented evidence that the structural integrity of the mouse sperm nuclear matrix may be necessary for the proper unpackaging of sperm DNA for participation in embryogenesis. It is likely that the sperm nuclear matrix contributes to the organisation of the sperm DNA and its disturbance can seriously damage the paternal genome or its expression. In this work, we confirm our previous data and further suggest that even very subtle changes in the sperm nuclear structure may have a significant impact on embryo development. As reported previously, dithiothreitol (DTT) in the presence of an ionic detergent, ATAB, destabilized the nuclear matrix as measured by the halo assay, and oocytes injected with these nuclei failed to develop. We also discovered that omitting the protease inhibitor PMSF from the buffers used to extract spermatozoa prevented sperm injected into oocytes from participating in development. The organization of DNA into loop domains by the nuclear matrix in these nuclei appeared normal, as measured by the halo assay. Oocytes injected with sperm nuclei that had been washed with ATAB in the presence of phenylmethylsulphonyl fluoride (PMSF) but in the absence of DTT resulted in live births. Neither DTT treatment nor the absence of PMSF would be expected to disrupt the integrity of the paternal DNA. The data therefore suggest that even very subtle alterations in the structural proteins of the nucleus are enough to deprive sperm DNA of the ability to contribute to embryonic development. PMID:10840874
Ward, W S; Kishikawa, H; Akutsu, H; Yanagimachi, H; Yanagimachi, R
The hepatic ?-tocopherol transfer protein (TTP) is required for optimal ?-tocopherol bioavailability in humans; mutations in the human TTPA gene result in the heritable disorder ataxia with vitamin E deficiency (AVED, OMIM #277460). TTP is also expressed in mammalian uterine and placental cells and in the human embryonic yolk-sac, underscoring TTP’s significance during fetal development. TTP and vitamin E are essential for productive pregnancy in rodents, but their precise physiological role in embryogenesis is unknown. We hypothesize that TTP is required to regulate delivery of ?-tocopherol to critical target sites in the developing embryo. We tested to find if TTP is essential for proper vertebrate development, utilizing the zebrafish as a non-placental model. We verify that TTP is expressed in the adult zebrafish and its amino acid sequence is homologous to the human ortholog. We show that embryonic transcription of TTP mRNA increases >7-fold during the first 24 hours following fertilization. In situ hybridization demonstrates that Ttpa transcripts are localized in the developing brain, eyes and tail bud at 1-day post fertilization. Inhibiting TTP expression using oligonucleotide morpholinos results in severe malformations of the head and eyes in nearly all morpholino-injected embryos (88% compared with 5.6% in those injected with control morpholinos or 1.7% in non-injected embryos). We conclude that TTP is essential for early development of the vertebrate central nervous system.
Miller, Galen W.; Ulatowski, Lynn; Labut, Edwin M.; Lebold, Katie M.; Manor, Danny; Atkinson, Jeffrey; Barton, Carrie L.; Tanguay, Robert L.; Traber, Maret G.
The plastid is an organelle vital to all photosynthetic and some non-photosynthetic eukaryotes. In the model plant Arabidopsis thaliana, a number of nuclear genes encoding plastid proteins have been found to be necessary for embryo development. However, the exact roles of plastids in this process remain largely unknown. Here we use publicly available datasets to obtain insights into the relevance of plastid activities to A. thaliana embryogenesis. By searching the SeedGenes database (http://www.seedgenes.org) and recent literature, we found that, of the 339 non-redundant genes required for proper embryo formation, 108 genes likely encode plastid-targeted proteins. Nineteen of these genes are necessary for development of preglobular embryos and/or their conversion to globular embryos, of which 13 genes encode proteins involved in non-photosynthetic metabolism. By contrast, among 38 genes which are dispensable for globular embryo formation but necessary for further development, only one codes for a protein involved in metabolism. Products of 21 of the 38 genes play roles in plastid gene expression and maintenance. Examination of RNA profiles of embryos at distinct growth stages obtained in laser-capture microdissection coupled with DNA microarray experiments revealed that most of the identified genes are expressed throughout embryo morphogenesis and maturation. These findings suggest that metabolic activities are required at preglobular and throughout all stages of embryo development, whereas plastid gene expression becomes necessary during and/or after the globular stage to sustain various activities of the organelle including photosynthetic electron transport.
Hsu, Shih-Chi; Belmonte, Mark F; Harada, John J; Inoue, Kentaro
Although the pathogenesis and treatment of anorexia nervosa and bulimia nervosa have traditionally been discussed in psychological terms, these eating disorders are always accompanied by somatic symptoms, symptoms which may become very serious. Moreover, as the anorexic or bulimic patient seeking medical treatment does not as a rule reveal the self-inflicted nature of her symptoms to the doctor, it is vital that physicians recognize such symptoms as manifestations of eating disorders. The article consists in a review of somatic complications commonly accompanying anorexia and bulimia, and their relationship to different body systems. PMID:10089732
Objective To examine the association between biological stress regulation and somatic complaints in young girls prior to the onset of clear psychopathology such as somatization disorder. Methods Salivary cortisol, heart rate variability (HRV), and negative mood were assessed in 48 12-year-old girls in response to the Trier Social Stress Test for Children (TSST-C). Parent and child report on the Children's Somatization Inventory was used to identify girls with high and low somatic complaints. Results Girls with high levels of somatic complaints had significantly higher initial levels of cortisol, which decreased over time, and showed a trend for a more limited HRV in response to the TSST-C than girls with low levels of somatic complaints. Conclusions High levels of cortisol and possibly low HRV among girls with somatic complaints may interfere with flexibility in responding to typical psychosocial stressors, which may increase vulnerability to the onset of somatic illnesses in females.
Opportunities for genetic errors during reproduc- tion are so frequent that one wonders how any of us turn out healthy. Although many of these errors are inconsequential, and some can beneficially in- crease human diversity, germ-line mutations un- derlie risks for thousands of diseases. Genetic dis- eases, however, need not be inherited through the germ line: somatic mutations can arise
Over the world, canine species, including the gray wolf, have been gradually endangered or extinct. Many efforts have been made to recover and conserve these canids. The aim of this study was to produce the endangered gray wolf with somatic cell nuclear transfer (SCNT) for conservation. Adult ear fibroblasts from a female gray wolf (Canis lupus) were isolated and cultured
Min Kyu Kim; Goo Jang; Hyun Ju Oh; Fibrianto Yuda; Hye Jin Kim; Woo Suk Hwang; Mohammad Shamim Hossein; Joung Joo Kim; Nam Shik Shin; Sung Keun Kang; Byeong Chun Lee
Chart reviews and telephone interviews with 72 sexual abuse victims found that 48 of the children had symptoms similar to the "rape trauma" syndrome. Two-thirds of victims commonly had somatic complaints (such as abdominal pain) and emotional/behavioral problems (runaway behavior, suicide attempts). (DB)
Deoxycholate C. diphtheriae extract was separated into fractions differing in the size of their molecules. Correlation between the molecular weight of each fraction, its specific protein content and its immunogenicity was observed. The high-molecular fraction (mol. wt. exceeding 300,000 daltons) was shown to be the protective somatic antigen of C. diphtheriae. PMID:6778025
Birger, M O; Grenkova, E P; Fish, N G; Zavodnova, T I; Kuzikov, A N
Discusses the somatic mind, a permeable materiality in which mind and body resolve into a single entity which is (re)formed by the constantly shifting boundaries of discursive and corporeal intertextualities. Addresses its importance in composition studies. Critiques the poststructuralist disregard of corporeality. (CR)
|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…
Kugler, Brittany B.; Bloom, Marlene; Kaercher, Lauren B.; Truax, Tatyana V.; Storch, Eric A.
Thyroid nodules can be found in up to 50% of inhabitants of iodine-deficient areas and are classified as hot or cold thyroid nodules according to their scintigraphic characteristics. Studies of hot thyroid nodules with comparable mutation detection methods and screening at least exon 10 of the TSH receptor reported frequencies for somatic TSH-receptor mutations ranging from 20 to 82% in
Three culture methods of carrot somatic embryos were compared: conventional shake flask culture, static suspension culture using Erlenmeyer flasks, and static suspension culture using petri dishes. Compared with the former two cultures, the last one resulted in an enhanced ratio of torpedo-shaped embryos and suppressed cotyledonary-stage embryo formation. PMID:16233794
The World Health Organization has recently launched an international study of somatoform disorders in different cultures. Five centres representing distinct cultures participated in phase I of the project, the main objective of which was to test the cross-cultural applicability and reliability of instruments for the assessment of somatoform disorders. The analysis of the assessed somatic symptoms showed that various aches
Mohan Isaac; Aleksandar Janca; Kimberly Christie Burke; Jorge Alberto Costa e Silva; Stanley Wilson Acuda; Carlo Altamura; C. R. Chandrashekar; Claudio T. Miranda; Gianluigi Tacchin
|Briefly reviews number of theories which address role of psychological factors in etiology of somatic disorders. Focuses on psychological treatment approaches that have been used to alleviate or reduce symptomatic behaviors associated with eating disorders, elimination disorders, and headaches in children. Discusses role of school psychologists…
Somatic sensation can be localized precisely, whereas local- ization of visceral sensation is vague, possibly reflecting differ- ences in the pattern of somatic and visceral input to the cere- bral cortex. We used functional magnetic resonance imaging to study the cortical processing of sensation arising from the proximal (somatic) and distal (visceral) esophagus in six healthy male subjects. Esophageal stimulation
Q. Aziz; D. G. Thompson; V. W. K. Ng; S. Hamdy; S. Sarkar; M. J. Brammer; E. T. Bullmore; A. Hobson; I. Tracey; L. Gregory; A. Simmons; S. C. R. Williams
Beginning 10 hours after fertilization, zygotes of Fucus distichus L. Powell incorporate 35S into polysaccharides as a sulfate ester of fucose. These sulfated polysaccharides are sequestered in only the rhizoid cell of the two-celled embryo and can serve as a marker of cellular differentiation. Zygotes were pulsed at different times after fertilization with Na235SO4 to identify and isolate the fucans localized within the region of cytoplasm destined to become the rhizoid cell. Low molecular weight pools of 35S were saturated within 60 minutes, with the greatest incorporation into ethanol-soluble and insoluble fractions occurring with 0.1 mm Na2SO4 in the artificial sea water medium. At the time of rhizoid formation, four fucose-containing polysaccharide fractions incorporated 35S. When each fraction was subjected to diethylaminoethyl chromatography, two components were eluted with KCl that contained over 84% of the fucose and 93% of the 35S of the particular fraction. Highvoltage paper electrophoresis of each fraction also resulted in the separation of these two major components. Both components from each of the four fractions behaved identically when separated by diethylaminoethyl chromatography and paper electrophoresis. By comparing the incorporation of 35S into the polysaccharide fractions at 4 and 16 hours after fertilization, the fucan-sulfate components that are localized in the cytoplasm at the time of rhizoid formation were isolated. Although sulfated polysaccharides in brown algae are reported to be very heterogeneous in terms of their sugar composition and complexes with other heteropolymers, we propose that there are two major components that are sulfated during early embryogenesis in Fucus. The location of these two sulfated polysaccharides in different chemical fractions may reflect their subcellular localization (e.g., cytoplasmic vesicles or cell walls), or their association with other heteropolymers.
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.
The origin of tetrapods is a complex question that webs together genetic, paleontological, developmental and physical facts. Basically, the development of embryos is described by a complex mix of mechanical movements and biochemical inductions of genetic origin. It is difficult to sort out in this scientific question what are the fundamental features imposed by conservation laws of physics, and by
Plastid gene expression is essential to embryogenesis in higher plants, but the underlying mechanism is obscure. Through molecular characterization of an embryo defective 16 (emb16) locus, here we report that the requirement of plastid translation for embryogenesis is dependent on the genetic background in maize (Zea mays). The emb16 mutation arrests embryogenesis at transition stage and allows the endosperm to develop largely normally. Molecular cloning reveals that Emb16 encodes WHIRLY1 (WHY1), a DNA/RNA binding protein that is required for genome stability and ribosome formation in plastids. Interestingly, the previous why1 mutant alleles (why1-1 and why1-2) do not affect embryogenesis, only conditions albino seedlings. The emb16 allele of why1 mutation is in the W22 genetic background. Crosses between emb16 and why1-1 heterozygotes resulted in both defective embryos and albino seedlings in the F1 progeny. Introgression of the emb16 allele from W22 into A188, B73, Mo17, Oh51a and the why1-1 genetic backgrounds yielded both defective embryos and albino seedlings. Similar results were obtained with two other emb mutants (emb12 and emb14) that are impaired in plastid protein translation process. These results indicate that the requirement of plastid translation for embryogenesis is dependent on genetic backgrounds, implying a mechanism of embryo lethality suppression in maize.
Plastid gene expression is essential to embryogenesis in higher plants, but the underlying mechanism is obscure. Through molecular characterization of an embryo defective 16 (emb16) locus, here we report that the requirement of plastid translation for embryogenesis is dependent on the genetic background in maize (Zea mays). The emb16 mutation arrests embryogenesis at transition stage and allows the endosperm to develop largely normally. Molecular cloning reveals that Emb16 encodes WHIRLY1 (WHY1), a DNA/RNA binding protein that is required for genome stability and ribosome formation in plastids. Interestingly, the previous why1 mutant alleles (why1-1 and why1-2) do not affect embryogenesis, only conditions albino seedlings. The emb16 allele of why1 mutation is in the W22 genetic background. Crosses between emb16 and why1-1 heterozygotes resulted in both defective embryos and albino seedlings in the F1 progeny. Introgression of the emb16 allele from W22 into A188, B73, Mo17, Oh51a and the why1-1 genetic backgrounds yielded both defective embryos and albino seedlings. Similar results were obtained with two other emb mutants (emb12 and emb14) that are impaired in plastid protein translation process. These results indicate that the requirement of plastid translation for embryogenesis is dependent on genetic backgrounds, implying a mechanism of embryo lethality suppression in maize. PMID:23840682
The normal development of eyes relies on proper signaling through Fibroblast growth factor (FGF) receptors, but the source and identity of cognate ligands have remained largely unknown. We have found that Fgf19 is expressed in the developing chicken retina. In situ hybridization discloses dynamic expression patterns for Fgf19 in the optic vesicle, lens primordia and retinal horizontal cells. Overall expression pattern of Fgf19 during chicken embryogenesis was also examined: Fgf19 is expressed in the regions associated with cranial placodes induction, boundary regions of rhombomeres, somites, specific groups of neural cells in midbrain, hindbrain, and those derived from epibranchial placodes, and the apical ectodermal ridge of limb buds. Expression pattern of the Fgf19-orthologous gene Fgf15 was further examined in the mouse developing eye. Fgf15 is expressed in the optic vesicle, a subset of progenitor cells of neural retina, and emerging ganglion and amacrine cells during retinogenesis. PMID:15465490