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1

Diphenylurea Derivatives Induce Somatic Embryogenesis in Citrus  

Microsoft Academic Search

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

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

2006-01-01

2

Somatic embryogenesis - Stress-induced remodeling of plant cell fate.  

PubMed

Plants as sessile organisms have remarkable developmental plasticity ensuring heir continuous adaptation to the environment. An extreme example is somatic embryogenesis, the initiation of autonomous embryo development in somatic cells in response to exogenous and/or endogenous signals. In this review I briefly overview the various pathways that can lead to embryo development in plants in addition to the fertilization of the egg cell and highlight the importance of the interaction of stress- and hormone-regulated pathways during the induction of somatic embryogenesis. Somatic embryogenesis can be initiated in planta or in vitro, directly or indirectly, and the requirement for dedifferentiation as well as the way to achieve developmental totipotency in the various systems is discussed in light of our present knowledge. The initiation of all forms of the stress/hormone-induced in vitro as well as the genetically provoked in planta somatic embryogenesis requires extensive and coordinated genetic reprogramming that has to take place at the chromatin level, as the embryogenic program is under strong epigenetic repression in vegetative plant cells. Our present knowledge on chromatin-based mechanisms potentially involved in the somatic-to-embryogenic developmental transition is summarized emphasizing the potential role of the chromatin to integrate stress, hormonal, and developmental pathways leading to the activation of the embryogenic program. The role of stress-related chromatin reorganization in the genetic instability of in vitro cultures is also discussed. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity. PMID:25038583

Fehér, Attila

2014-07-17

3

Zygotic embryogenesis versus somatic embryogenesis  

Microsoft Academic Search

This review will summarize molecular and genetic ana- lyses aimed at identifying the mechanisms underlying the sequence of events during plant zygotic embryo- genesis. These events are being studied in parallel with the histological and morphological analyses of somatic embryogenesis. The strength and limitations of somatic embryogenesis as a model system will be discussed briefly. The formation of the zygotic

V. L. Dodeman; G. Ducreux; M. Kreis

1997-01-01

4

Developmental pathways of somatic embryogenesis  

Microsoft Academic Search

Somatic embryogenesis is defined as a process in which a bipolar structure, resembling a zygotic embryo, develops from a non-zygotic cell without vascular connection with the original tissue. Somatic embryos are used for studying regulation of embryo development, but also as a tool for large scale vegetative propagation. Somatic embryogenesis is a multi-step regeneration process starting with formation of proembryogenic

Sara von Arnold; Izabela Sabala; Peter Bozhkov; Julia Dyachok; Lada Filonova

2002-01-01

5

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

PubMed

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

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

2014-09-25

6

Somatic embryogenesis in peanut ( Arachis hypogaea L.): stimulation of direct differentiation of somatic embryos by forchlorfenuron (CPPU)  

Microsoft Academic Search

The ability of forchlorfenuron (CPPU), a substituted phenylurea compound, for inducing somatic embryogenesis in peanut (Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Embryogenic response was dependent on applied CPPU concentrations. Exposure of seedlings for only two days to CPPU induced somatic embryogenesis, but the most

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

1994-01-01

7

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

NASA Astrophysics Data System (ADS)

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

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

2006-11-01

8

Somatic embryogenesis in peanut: Influence of growth regulators and sugars  

Microsoft Academic Search

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

Susan Eapen; Leela George

1993-01-01

9

Secondary somatic embryogenesis and applications in plant breeding  

Microsoft Academic Search

Secondary somatic embryogenesis is the phenomenon whereby new somatic embryos are initiated from somatic embryos. Such cultures have been described in at least 80 Gymnosperm and Angiosperm species. In the initial step (primary somatic embryogenesis) such cultures have to be started from plant explants. In general, primary somatic embryogenesis from vegetative plant explants is, indirect and mostly driven by auxin

C. J. J. M. Raemakers; E. Jacobsen; R. G. F. Visser

1995-01-01

10

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

Microsoft Academic Search

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

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

1998-01-01

11

In vitro somatic embryogenesis and plant regeneration of cassava  

Microsoft Academic Search

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

László Szabados; Rodrigo Hoyos; William Roca

1987-01-01

12

Secondary somatic embryogenesis and plant regeneration in cassava  

Microsoft Academic Search

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

James A. Stamp; Graham G. Henshaw

1987-01-01

13

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

14

Influence of atmospheric gases, particularly ethylene, on somatic embryogenesis of Hevea brasiliensis  

Microsoft Academic Search

The atmosphere of the culture vessel is an important factor for successful somatic embryogenesis in Hevea brasiliensis (Müll. Arg.). Considerable release of carbon dioxide and ethylene occurred during the development of calli. By avoiding the accumulation of gas, unconfined conditions were the most favourable for inducing somatic embryogenesis. Trapping of ethylene was as favourable for calli development and for somatic

Erik Auboiron; Marc-Philippe Carron; Nicole Michaux-Ferričre

1990-01-01

15

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

Microsoft Academic Search

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

D. Vasic; G. Alibert; D. Skoric

2001-01-01

16

Soybean somatic embryogenesis: Effects of nutritional, physical and chemical factors  

Microsoft Academic Search

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 somatic embryogenesis. 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

1987-01-01

17

Secondary somatic embryogenesis of carnation ( Dianthus caryophyllus L.)  

Microsoft Academic Search

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

Omid Karami; Ali Deljou; Gona Karimi Kordestani

2008-01-01

18

Somatic embryogenesis and organogenesis from immature embryo cotyledons of three sour cherry cultivars ( Prunus cerasus L.)  

Microsoft Academic Search

Immature cotyledons of open-pollinated fruits from three sour cherry cultivars (Prunus cerasus L.) were excised and cultured on Murashige and Skoog medium supplemented with various combinations of auxin and cytokinin to induce somatic embryogenesis. Somatic embryogenesis occurred principally when using the combinations of 2,4-dichlorophenoxyacetic acid plus kinetin. Using a-naphthaleneacetic acid or 6-benzylaminopurine reduced the incidence of somatic embryogenesis. Conversely, formation

Haoru Tang; Zhenglong Ren; Gabi Krczal

2000-01-01

19

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

Microsoft Academic Search

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

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

2007-01-01

20

Plant regeneration via somatic embryogenesis in Schlumbergera truncata  

Microsoft Academic Search

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

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

2006-01-01

21

Soybean somatic embryogenesis: Effects of hormones and culture manipulations  

Microsoft Academic Search

Somatic embryos were induced in cultures of immature soybean (Glycine max (L.) Merr) embryos, or isolated cotyledons on MS modified medium supplemented with NAA and 2,4-D, BAP and ABA. When NAA and 2,4-D were compared at similar concentrations (25 and 23 µM), 2,4-D produced larger number of somatic embryos, however, embryogenesis efficiency was improved in media containing NAA by using

Paul A. Lazzeri; David F. Hildebrand; Glenn B. Collins

1987-01-01

22

Walnut somatic embryogenesis: physiological and histological aspects  

E-print Network

-Arboriculture, Bordeaux) from a half-sib family collected on black walnut (NG 23), which naturally produces a high levelWalnut somatic embryogenesis: physiological and histological aspects D. Cornu Amdlioration des nuts of other walnut species (Tulecke and McGranahan, 1985; Cornu, 1988). For Juglans regia the best

Paris-Sud XI, Université de

23

Somatic embryogenesis in Hedychium bousigonianum  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

24

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

PubMed

Somatic embryos were regenerated in vitro from calamondin style-stigma explants cultured in the presence of N (6)-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N'-benzothiazol-6-ylurea (PBU) and N,N'-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 muM) were able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF) conditions. In order to verify the genetic stability of the regenerants, 27 plants coming from different embryogenic events were randomly selected from each different culture condition and evaluated for somaclonal variations using inter-simple sequence repeat and random amplified polymorphic DNA analyses. We observed that 2,3-MDPU and PBU gave 3.7% of somaclonal mutants, whereas 4-CPPU gave 7.4% of mutants. No somaclonal variability was observed when plantlets were regenerated in BAP or HF medium. Although diphenylurea derivatives show a higher embryogenic potential as compared to BAP, they induce higher levels of somaclonal variability. This finding should be taken in consideration when new protocols for clonal propagation are being developed. PMID:17333016

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

2007-08-01

25

Long-term somatic embryogenesis and maturation of somatic embryos in Hevea brasiliensis  

Microsoft Academic Search

A high frequency of secondary embryogenesis was induced from isolated early cotyledonary-stage somatic embryos of Hevea brasiliensis. A long-term embryogenic line was established by the use of recurrent embryogenesis and maintained for 3 years on hormone-free medium by the transfer of selected proembryogenic masses every 10 days.The addition of 234 mM sucrose as stress with sucrose and 10?5 M abscisic

Françoise Cailloux; Josiane Julien-Guerrier; Laurent Linossier; Alain Coudret

1996-01-01

26

Callus induction and somatic embryogenesis of Phalaenopsis  

Microsoft Academic Search

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

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

1998-01-01

27

Induction of somatic embryogenesis in Azadirachta indica  

Microsoft Academic Search

A modified culture protocol has been developed for the induction of somatic embryogenesis in Azadirachta indica (neem). Embryogenic calluses were initiated from cotyledons or hypocotyls using a Murashige and Skoog (MS) agar medium supplemented\\u000a with 0.5 mg l?1 ?-napthaleneacetic acid (NAA), 1 mg l?1 6-benzylaminopurine (BA), 1 g l?1 casein hydrolysate, and 50 g l?1 sucrose. The calluses, when transferred

Wei Wen Su; Wen-Ing Hwang; Se Young Kim; Yoneo Sagawa

1997-01-01

28

Direct Somatic Embryogenesis in Northern Red Oak (Quercus rubra L.)  

E-print Network

Direct Somatic Embryogenesis in Northern Red Oak (Quercus rubra L.) G. Vengadesan and Paula M these problems is through using an in vitro culture method involving somatic embryogenesis along Research Station, HTIRC, 715 West State Street, West Lafayette, IN 47907 Abstract Somatic embryo cultures

29

Studies on Somatic Embryogenesis in Sweetpotato  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

30

Studies for Somatic Embryogenesis in Sweet Potato  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

31

A new approach to direct somatic embryogenesis in Medicago  

Microsoft Academic Search

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

P. Denchev; M. Velcheva; A. Atanassov

1991-01-01

32

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

Microsoft Academic Search

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

W. L. Koh; C. S. Loh

2000-01-01

33

Genotype specificity of the somatic embryogenesis response in cotton  

Microsoft Academic Search

Thirty eight cultivars, strains, and races ofGossypium were screened for somatic embryogenesis with the protocols developed as a model forG. hirsutum L. cv. Coker 312. Four classes of response were identified; high, moderate, low, and non-embryogenic. Four cultivars were further screened with 13 growth regulator regimes to determine if culture environment could change the classification or induce a higher level

Norma L. Trolinder; Chen Xhixian

1989-01-01

34

Somatic embryogenesis: A model for early development in higher plants  

E-print Network

The ability to produce morphologically and developmentally normal embryos and, indeed, whole plants from undifferentiated somatic cells in culture, through the process of somatic embryogenesis, resides uniquely within the plant kingdom.

J. Lynn Zimmerman

1993-01-01

35

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

Microsoft Academic Search

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

B. Chitra Devi; V. Narmathabai

2011-01-01

36

Somatic embryogenesis in cell cultures of Glycine species.  

PubMed

This report describes the development of procedures for the production of somatic embryos in cell cultures of Glycine species including soybean. The conditions for callus induction and initiation of rapidly growing cell suspension cultures were defined. Methods for inducing embryogenesis were tested on 16 lines of several Glycine species and cultivars of soybean. The SB-26 Culture of a G. soja gave the best results and was used in the experiments. Embryogenesis required the presence of picloram or 2,4-D. AMO 1618, CCC, PP-333 and Ancymidol enhanced the embryogenesis frequency. Plants of the G. soja (SB-26) were grown to maturity from seed-derived shoot tips. Characteristics of the plants are discussed. PMID:24258054

Gamborg, O L; Davis, B P; Stahlhut, R W

1983-08-01

37

Role of trace elements in somatic embryogenesis A PIXE study  

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

38

Hormone-response mutants of Arabidopsis thaliana (L.) Heynh. impaired in somatic embryogenesis  

Microsoft Academic Search

Plant hormones are considered to be the key factors involved in triggering in vitro induced plant morphogenesis, including somatic embryogenesis (SE). Mutants affected in SE and altered in hormonal response therefore provide valuable material for genetic research on in vitro induced plant embryogenesis. The capacity for SE was studied in 27 mutants with defects in response to different plant hormones:

Ma?gorzata D. Gaj; Aneta Trojanowska; Agnieszka Ujczak; Martyna M?drek; Aleksandra Kozio?; Beata Garbaciak

2006-01-01

39

Induction of somatic embryogenesis in cultured cells of Chenopodium quinoa  

Microsoft Academic Search

A major limiting factor for quinoa cultivation as a grain crop on a large scale are virus diseases, in particularly seed borne diseases. Therefore, a somatic embryogenesis protocol is a necessary tool to produce virus free plants. Somatic embryogenesis offers the possibility of mass production of transgenic plants and therefore can be used easily to study the effect on plants

S. Eisa; H. W. Koyro; K. H. Kogel; J. Imani

2005-01-01

40

Spaceflight reduces somatic embryogenesis in orchardgrass (Poaceae)  

NASA Technical Reports Server (NTRS)

Somatic embryos initiate and develop from single mesophyll cells in in vitro cultured leaf segments of orchard-grass (Dactylis glomerata L.). Segments were plated at time periods ranging from 21 to 0.9 d (21 h) prior to launch on an 11 d spaceflight (STS-64). Using a paired t-test, there was no significant difference in embryogenesis from preplating periods of 14 d and 21 d. However, embryogenesis was reduced by 70% in segments plated 21 h before launch and this treatment was significant at P=0.0001. The initial cell divisions leading to embryo formation would be taking place during flight in this treatment. A higher ratio of anticlinal:periclinal first cell divisions observed in the flight compared to the control tissue suggests that microgravity affects axis determination and embryo polarity at a very early stage. A similar reduction in zygotic embryogenesis would reduce seed formation and have important implications for long-term space flight or colonization where seeds would be needed either for direct consumption or to grow another generation of plants.

Conger, B. V.; Tomaszewski, Z. Jr; McDaniel, J. K.; Vasilenko, A.

1998-01-01

41

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

PubMed Central

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

Chen, Jen-Tsung

2014-01-01

42

Somatic embryogenesis and plant regeneration from leaflets of peanut, Arachis hypogaea  

Microsoft Academic Search

Somatic embryos were induced on peanut (Arachis hypogaea) leaflets from aseptically germinated embryo axes. Leaflet size influenced percent somatic embryogenesis; 5–8 mm long cut leaflets were superior to 2–3 mm long uncut leaflets. Maximum embryogenesis of 14.6% was obtained after a 15 d incubation on induction medium (modified MS with B5 vitamins, 30 g\\/l sucrose, 4 g\\/l Gel-Gro, 40 mg\\/l

Charleen M. Baker; Hazel Y. Wetzstein

1992-01-01

43

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

E-print Network

ENHANCING THE FREQUENCY OF SOMATIC EMBRYOGENESIS FOLLOWING AGROBACTERIUM-MEDIATED TRANSFORMATION media containing 25 mg l21 hygromycin in subsequent selection periods. However, somatic embryogenesis embryogenic explants along with the location of embryogenesis- and transformation-competent cells

Korban, Schuyler S.

44

Somatic embryogenesis in peanut (Arachis hypogaea L.): stimulation of direct differentiation of somatic embryos by forchlorfenuron (CPPU).  

PubMed

The ability of forchlorfenuron (CPPU), a substituted phenylurea compound, for inducing somatic embryogenesis in peanut (Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Embryogenic response was dependent on applied CPPU concentrations. Exposure of seedlings for only two days to CPPU induced somatic embryogenesis, but the most effective treatment was to induce seed germination on media supplemented with either 2.5 or 4.0 ?M CPPU and to maintain the seedlings on the same medium. Number of somatic embryos and the frequency of embryogenesis was higher for younger seedlings (up to 9 days), regardless of the CPPU concentrations and seedlings older than 21 days failed to produce somatic embryos. Removal of cotyledons from the seeds drastically reduced the embryogenic potential of the seedlings. Somatic embryos developed into whole plants following their separation and subculture on a medium lacking growth regulators. The induction of somatic embryos using CPPU as a sole growth regulator may provide a useful system to study the role of this compound in plant morphogenesis. PMID:24192883

Murthy, B N; Saxena, P K

1994-12-01

45

Bioreactors for Coffee Mass Propagation by Somatic Embryogenesis  

Microsoft Academic Search

Coffee somatic embryogenesis in liquid medium is a powerful alternative to other vegetative propagation techniques for mass propagation of selected Coffea canephora (Robusta) clones and F1 Coffea arabica hybrids. This review presents the different types of bioreactors used for coffee somatic embryogenesis by Nestlé R&D Centre-Tours and by other scientific teams. Mechanically agitated bioreactors were used for the production of

Jean-Paul Ducos; Charles LambotVincent Pétiard

2007-01-01

46

Genetic variation in somatic embryogenesis of Rosa Hybrida L.  

E-print Network

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

Burrell, Anna Mildred

2004-09-30

47

In vitro Propagation of Euphorbia pulcherrima Willd. Through Somatic Embryogenesis  

Microsoft Academic Search

Euphorbia pulcherrima Willd. is one of the most popular ornamental houseplants. A protocol was developed for multiplication of E. pulcherrima through somatic embryogenesis from nodal explants. The induction of somatic embryogenesis in red pigmented callus was achieved on MS supplemented with 2ip (9.8 µM) and NAA (2.69 µM). Reduced level of NAA (0.54 µM) in the same medium caused maturation

Yogesh T. Jasrai; K. N. Thaker; M. C. D'Souza

48

Direct somatic embryogenesis and synthetic seed production from Paulownia elongata.  

PubMed

We have developed a reproducible system for efficient direct somatic embryogenesis from leaf and internodal explants of Paulownia elongata. The somatic embryos obtained were subsequently encapsulated as single embryos to produce synthetic seeds. Several plant growth regulators [6-benzylaminopurine, indole-3-acetic acid, alpha-naphthaleneacetic acid, kinetin and thidiazuron (TDZ)] alone or in combination were tested for their capacity to induce somatic embryogenesis. The highest induction frequencies of somatic embryos were obtained on Murashige and Skoog (MS) medium supplemented with 3% sucrose, 0.6% Phytagel, 500 mg l(-1) casein hydrolysate and 10 mg l(-1) TDZ (medium MS10). Somatic embryos were induced from leaf (69.8%) and internode (58.5%) explants on MS10 medium after 7 days. Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos into plantlets on MS basal media. The maturation frequency of somatic embryos from leaf and internodal explants was 50.8% and 45.8%, respectively. Subculturing of mature embryos led to their germination on the same medium with a germination frequency of 50.1% and 29.8% from leaf and internode explants, respectively. Somatic embryos obtained directly on leaf explants were used for encapsulation in liquid MS medium containing different concentrations of sodium alginate with a 30-min exposure to 50 m M CaCl(2). A 3% sodium alginate concentration provided a uniform encapsulation of the embryos with survival and germination frequencies of 73.7% and 53.3%, respectively. Storage at 4 degrees C for 30 days or 60 days significantly reduced the survival and complete germination frequencies of both encapsulated and non-encapsulated embryos relative to those of non-stored somatic embryos. However, the survival and germination rates of encapsulated embryos increased following storage at 4 degrees C. After 30 days or 60 days of storage, the survival rates of encapsulated embryos were 67.8% and 53.5% and the germination frequencies were 43.2% and 32.4%, respectively. These systems could be useful for the rapid clonal propagation and dissemination of synthetic seed material of Paulownia elongata. PMID:12827435

Ipekci, Z; Gozukirmizi, N

2003-08-01

49

Somatic embryogenesis in Arachis hypogaea L.: genotype comparison  

Microsoft Academic Search

Somatic embryogenesis and embryogenic callus formation occurred from immature cotyledon and embryo axis explants of seven peanut (Arachis hypogaea L.) genotypes including one valencia, three Spanish and three Virginia botanical types. The initiation medi- um consisted of Murashige and Skoog's salts and vitamins with 3% sucrose and 0.5 mg\\/l picloram. There were significant differences among genotypes for somatic embryo formation,

Peggy Ozias-Akins; William F. Anderson; C. Corley Holbrook

1992-01-01

50

Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland  

E-print Network

Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland cotton: embryogenic potential, Gossypium hirsutum L., Polyamines Abstract Improvement in somatic embryogenesis has and Skoog; NAA ­ a-naphthalene acetic acid; SE ­ somatic embryo Somatic embryogenesis is the preferred plant

Chee, Peng W.

51

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

Microsoft Academic Search

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

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

2006-01-01

52

Somatic embryogenesis for efficient micropropagation of guava (Psidium guajava L.).  

PubMed

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. Somatic embryogenesis for efficient micropropagation of guava (P. guajava L.) has been developed to fill up the gap. Somatic embryogenesis 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 somatic embryogenesis 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 somatic embryogenesis is optimized for high efficiency micropropagation of guava species. PMID:23179697

Akhtar, Nasim

2013-01-01

53

Somatic embryogenesis in in vitro culture of Leucojum vernum L.  

PubMed

Procedures for somatic embryogenesis (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

Ptak, Agata

2010-01-01

54

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

E-print Network

G.S. Pullman and S. JohnsonSomatic embryogenesis initiation of loblolly pine Original article Somatic embryogenesis in loblolly pine (Pinus taeda L.): improving culture initiation rates Gerald S-pollinated families, initiation rates ranged from 3­33%, averaging 16%. Loblolly pine / somatic embryogenesis

Boyer, Edmond

55

Plant regeneration via somatic embryogenesis in pea ( Pisum sativum L.)  

Microsoft Academic Search

Whole plant regeneration via somatic embryogenesis 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

1987-01-01

56

Somatic embryogenesis from pea embryos and shoot apices  

Microsoft Academic Search

Conditions were defined for plant regeneration via somatic embryogenesis in pea, using explants from immature zygotic embryos or from shoot apices. For the induction of somatic embryos, an auxin (picloram or 2,4-dichlorophenoxyacetic acid) was required. Embryogenic callus originated from embryonic axis tissue of immature embryos and from the axillary-bud region and the plumula of shoot apices. A clear effect of

Wilfried Kysely; Hans-Jörg Jacobsen

1990-01-01

57

Micropropagation of Panax notoginseng by somatic embryogenesis and RAPD analysis of regenerated plantlets  

Microsoft Academic Search

Somatic embryogenesis was induced in callus tissues derived from young flower buds of Panax notoginseng via callus within 18 weeks of culture. The mature somatic embryos were germinated on half-strength Murashige and Skoog's (MS) medium supplemented with gibberellic acid A3(GA) and 6-benzyladenine (BA). The most suitable medium for optimal root formation proved to be MS medium supplemented with 1-naphthaleneacetic acid

Y. Shoyama; Xuan Xuan Zhu; R. Nakai; S. Shiraishi; H. Kohda

1997-01-01

58

Somatic embryogenesis and plant regeneration from leaf tissues of Panicum maximum Jacq  

Microsoft Academic Search

Somatic embryogenesis was induced in proliferating leaf segments of Panicum maximum Jacq., cultured on Murashige and Skoog's nutrient medium containing 2,4-dichlorophenoxyacetic acid and coconut milk. The embryoids gave rise to plants on a medium containing gibberellic acid. The plants were successfully transplanted to soil and grown to maturity. Histological examination of proliferating leaves showed that the embryogenic callus tissue was

C. Lu; I. K. Vasil

1981-01-01

59

Yield performance of cacao propagated by somatic embryogenesis and grafting  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

60

A new approach to direct somatic embryogenesis in Medicago.  

PubMed

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

Denchev, P; Velcheva, M; Atanassov, A

1991-09-01

61

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

PubMed

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

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

2010-07-01

62

Somatic embryogenesis and plant regeneration from immature zygotic embryos of Hinoki cypress ( Chamaecyparis obtusa Sieb. et Zucc.)  

Microsoft Academic Search

We established a plant regeneration system for Hinoki cypress ( Chamaecyparis obtusa) via somatic embryogenesis. Embryogenic tissues were successfully induced on three kinds of Smith media from megagametophyte explants containing pre-cotyledonary embryos of C. obtusa plus-trees. Factors affecting somatic embryo maturation were examined. The concentration of polyethylene glycol 4000 in the medium was a critical factor for embryo maturation and its

T. Taniguchi; M. Kurita; N. Itahana; T. Kondo

2004-01-01

63

Somatic embryogenesis in Arabidopsis thaliana is facilitated by mutations in genes repressing meristematic cell divisions  

Microsoft Academic Search

Embryogenesis in plants can commence from cells other than the fertilized egg cell. Embryogenesis initiated from somatic cells in vitro is an attractive system for studying early embryonic stages when they are accessible to experimental manipulation. Somatic embryogenesis in Arabidopsis offers the additional advantage that many zygotic embryo mutants can be studied under in vitro conditions. Two systems are available.

Andreas P. Mordhorst; Keete J. Voerman; Marijke V. Hartog; Ellen A. Meijer; Jacques van Went; Maarten Koornneef; Vries de S. C

1998-01-01

64

Control of somatic embryogenesis and embryo development by AP2 transcription factors  

PubMed Central

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 somatic embryogenesis and acted cooperatively with at least one other motif, euANT2, in the regulation of somatic embryogenesis and embryo development in transgenic Arabidopsis. The results provide new insights into the mechanisms by which BBM governs embryogenesis. Electronic supplementary material The online version of this article (doi:10.1007/s11103-010-9674-8) contains supplementary material, which is available to authorized users. PMID:20798978

El Ouakfaoui, Souad; Schnell, Jaimie; Abdeen, Ashraf; Colville, Adam; Labbé, Hélčne; Han, Shuyou; Baum, Bernard; Laberge, Serge

2010-01-01

65

Somatic embryogenesis from Sorghum bicolor leaves  

Microsoft Academic Search

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

Wolfgang Wernicke; Richard Brettell

1980-01-01

66

Regeneration of Syngonium podophyllum ‘Variegatum’ through direct somatic embryogenesis  

Microsoft Academic Search

A simple and effective method of regenerating Syngonium podophyllum ‘Variegatum’ via direct somatic embryogenesis has been established. Leaf and petiole explants were cultured on Murashige\\u000a 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 either ?-naphthalene acetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Somatic embryos directly formed at one or two sides of petiole explants on MS

Qian Zhang; Jianjun Chen; Richard J. Henny

2006-01-01

67

Somatic embryogenesis in Zea mays L  

Microsoft Academic Search

Immature embryos of 12 genotypes of Zea mays L. were cultured on agar nutrient media containing various concentrations of 2,4-dichlorophenoxyacetic acid and sucrose. An opaque, white, compact and organized callus tissue was formed by the proliferation of the scutellar cells present in the vicinity of the scutellar node near the coleorhiza. Well-organized somatic embryos were formed on the surface of

C. Lu; I. K. Vasil; P. Ozias-Akins

1982-01-01

68

Somatic embryogenesis and analysis of peroxidases in Phoenix dactylifera L  

Microsoft Academic Search

To determine some physiological parameters implicated in somatic embryogenesis in date palm (Phoenix dactylifera L.), peroxidases have been studied. Activated charcoal commonly used in date palm tissue culture as an essential antibrowning\\u000a factor decreased cellular protein contents and peroxidase activities. During the first months of culture, the conventionally\\u000a used medium (100 mg dm?3 of 2,4-dichlorophenoxyacetic acid, 3 g dm?3 charcoal)

I. El Hadrami; M. Baaziz

1995-01-01

69

Somatic embryogenesis in suspension cultures of Gossypium klotzschianum anderss  

Microsoft Academic Search

Somatic embryoids differentiated in suspension cultures of G. klotzschianum after 3–4 weeks of culture in a liquid medium containing glutamine (optimally, 10–15 mM). Embryogenesis occurred after a preculture of callus on a medium containing 10 mg\\/l of the cytokinin, 2iP. The embryoids had meristematic regions, a well formed epidermis, and formed roots and vestigial leaves. Asparagine was much less effective

H. James Price; Roberta H. Smith

1979-01-01

70

Callus friability and somatic embryogenesis in Hevea brasiliensis  

Microsoft Academic Search

The influence of plant growth regulators, sucrose, calcium and various macronutrient media on callus friability and somatic\\u000a embryogenesis was investigated inHevea brasiliensis Mll. Arg. Friable and embryogenic calli were spontaneously formed in two rubber tree clones (PR 107 and RRIM 600) on the\\u000a Medium for Hevea (MH), with 3,4-dichlorophenoxyacetic acid (3,4-d), kinetin and sucrose, while compact embryogenic calli were enhanced

Pascal Montoro; Hervé Etienne; Nicole Michaux-Ferričre; Marc-Philippe Carron

1993-01-01

71

Plant regeneration via somatic embryogenesis and shoot organogenesis from immature cotyledons of Camellia nitidissima Chi.  

PubMed

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 somatic embryogenesis, 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 somatic embryogenesis 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 somatic embryogenesis. 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

2013-09-01

72

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

E-print Network

Gene Expression Patterns During Somatic Embryogenesis in Maize Tissue Culture: A Bayesian Approach multiple cDNA slide scans. Section 4 applies the proposed approach in a maize embryogenesis experimental

73

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

E-print Network

Incorporating Multiple cDNA Microarray Slide Scans -Application to Somatic Embryogenesis in Maize 1 into a single estimate. We illustrate the use of the model using expression data from a maize embryogenesis

74

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

Microsoft Academic Search

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

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

2003-01-01

75

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

Microsoft Academic Search

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

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

1999-01-01

76

Somatic embryogenesis from stem and leaf explants of Quercus robur L  

Microsoft Academic Search

Internodal and leaf segments from pedunculate oak (Quercus robur L.) seedlings were used as explant source to induce somatic embryogenesis. Auxin treatment influenced embryogenic response, which\\u000a only occurred in explants initially cultured on media containing 4 mg\\/l naphthaleneacetic acid (NAA) and different benzyladenine\\u000a (BA) concentrations. After 6 weeks of culture on induction medium, the explants were transferred to medium supplemented

B. Cuenca; M. T. Martínez; A. Ballester; A. M. Vieitez

1999-01-01

77

The effects of ancymidol, abscisic acid, uniconazole and paclobutrazol on somatic embryogenesis of asparagus  

Microsoft Academic Search

Summary  The effects of ancymidol, abscisic acid (ABA), uniconazole, and paclobutrazol on asparagus somatic embryogenesis were evaluated. Calli induced from seedlings of genotype G447 were transferred to embryo induction medium (MS plus 3% sucrose, 0.1 mg L–1 NAA, 0.5 mg L–1 kinetin and 3% gelrite), with different concentrations of these compounds. After 8 weeks, the recovered bipolar or globular embryos were

Baochun Li; David J. Wolyn

1995-01-01

78

Improvement of somatic embryogenesis and plant recovery in cassava  

Microsoft Academic Search

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

1993-01-01

79

Somatic embryogenesis in Agave tequilana Weber cultivar azul  

Microsoft Academic Search

Somatic embryogenesis was achieved from leaves of Agave tequilana Weber cultivar azul utilizing MS medium supplemented with L2 vitamins and the addition of cytokinins: 6-benzylaminopurine\\u000a (BA), 1-phenyl-3(1,2,3-thiadiazol-5-yl)urea (TDZ), 6-(?-?-dimethylamino)purine (2ip) and 6-furfurylaminopurine (KIN), combined\\u000a with the auxin 2,4-dichlorophenoxyacetic acid (2,4-D). Differences among the six genotypes studied with regard to their embryogenic\\u000a response in culture were found. Embryos produced by genotype

Liberato Portillo; Fernando Santacruz-Ruvalcaba; Antonia Gutiérrez-Mora; Benjamín Rodríguez-Garay

2007-01-01

80

Regeneration of Melia volkensii Gürke (Meliaceae) through direct somatic embryogenesis  

Microsoft Academic Search

Experiments were conducted to study plant regeneration through direct somatic embryogenesis using mature zygotic embryo and\\u000a cotyledonary explants from seeds of Melia volkensii stored for 12 months. Explants were cultured on Murashige and Skoog (MS) medium supplemented with BAP, NAA and 2,4-D\\u000a (0.5, 1.0 and 2.0 mg l?1) alone, and BAP (0.5, 1.0, 2.0 and 4.0 mg l?1) in combination with 2,4-D or NAA (0.2

S. A. Indieka; D. W. Odee; G. M. Muluvi; K. N. Rao; J. Machuka

2007-01-01

81

High-frequency plant regeneration through cyclic secondary somatic embryogenesis in black pepper ( Piper nigrum L.)  

Microsoft Academic Search

A high-frequency plantlet regeneration protocol was developed for black pepper (Piper nigrum L.) through cyclic secondary somatic embryogenesis. Secondary embryos formed from the radicular end of the primary somatic embryos which were originally derived from micropylar tissues of germinating seeds on growth regulator-free SH medium in the absence of light. The process of secondary embryogenesis continued in a cyclic manner

R. Ramakrishnan Nair; S. Dutta Gupta

2006-01-01

82

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

E-print Network

Y.-S. ParkConifer somatic embryogenesis in clonal forestry Original article Implementation of conifer somatic embryogenesis in clonal forestry: technical requirements and deployment considerations Yill-Sung Park* Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, PO Box

Paris-Sud XI, Université de

83

Somatic embryogenesis and plant regeneration in Psidium guajava L. cv. Banarasi local  

Microsoft Academic Search

A protocol for plant regeneration by somatic embryogenesis was developed in guava cv. Banarasi local by using immature zygotic embryo explants. Best induction of somatic embryogenesis was achieved from 10-week-old zygotic embryos on MS medium supplemented with 2,4-d (4.52?M) and 5% sucrose. Maximum number of somatic embryos was produced when zygotic embryo explants were transferred to growth regulator free full

Manoj K. Rai; N. Akhtar; V. S. Jaiswal

2007-01-01

84

SOMATIC EMBRYOGENESIS AND REGENERATION OF PLANTLET IN SAFFRON, CROCUS SATIVUS L  

Microsoft Academic Search

Somatic embryogenesis was initiated in C. sativus L. from shoot meristems on LS medium containing BAP (2×10-5 M)+NAA (2×10-5 M). Various stages of somatic embryogenesis were observed in the same medium and the development was asynchronous. Somatic embryo development proceeded through well recognized sequences (globular to embryoids) with clearly discernible bipolar regions. Matured embryos could be germinated on half-strength MS

H. Ebrahimzadeh; R. Karamian; M. R. Noori-Daloii

85

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

86

Somatic embryogenesis and plant regeneration from immature zygotic embryos of Hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.).  

PubMed

We established a plant regeneration system for Hinoki cypress (Chamaecyparis obtusa) via somatic embryogenesis. Embryogenic tissues were successfully induced on three kinds of Smith media from megagametophyte explants containing pre-cotyledonary embryos of C. obtusa plus-trees. Factors affecting somatic embryo maturation were examined. The concentration of polyethylene glycol 4000 in the medium was a critical factor for embryo maturation and its effective concentration was 150 g/l. The addition of 30 g/l maltose to the medium had a positive effect on embryo maturation, but sucrose was ineffective. The mature somatic embryos germinated at a germination frequency of approximately 60%, and the presence of activated charcoal was effective in stimulating plantlet growth. The plantlets acclimatized successfully in a greenhouse. To our knowledge, this is first report describing details of a plant regeneration method for C. obtusa via somatic embryogenesis. PMID:15141322

Taniguchi, T; Kurita, M; Itahana, N; Kondo, T

2004-08-01

87

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

Microsoft Academic Search

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

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

2001-01-01

88

Industrial scale in vitro propagation by Somatic Embryogenesis Applied research project  

E-print Network

1 Industrial scale in vitro propagation by Somatic Embryogenesis Applied research project Swe involves large scale production of mature somatic embryos in a liquid-based bioreactor system, harvest production of somatic embryo plants. This will involve various laboratory tasks that support the running

Uppsala Universitet

89

Induction of high-frequency somatic embryogenesis in geranium (Pelargonium x hortorum Bailey cv Ringo Rose) cotyledonary cultures.  

PubMed

The cv Ringo Rose of hybrid seed geranium (Pelargonium x hortorum Bailey), previously shown to be recalcitrant in culture, produced somatic embryos when cotyledonary explants were cultured on regeneration medium containing thidiazuron (TDZ), forchlorfenuron (CPPU), or a combination of indole-3-acetic acid and N(6) benzylaminopurine (IAA+BAP). Amendment of the basal medium with TDZ (0.5 ?M) was the most effective treatment. Addition of amino acids to the medium promoted the growth of somatic embryos. Retention of the proximal region of the cotyledon was crucial for regeneration, but the removal of the distal 1/3 to 1/2 cotyledon had no significant effect on somatic embryogenesis. Cotyledonary explants formed somatic embryos in higher frequency and much earlier than hypocotyl explants cultured on the same medium. The somatic embryos induced on cotyledonary explants were germinated on basal medium. More than 70% of the somatic embryos were converted into plants and transferred to soil. PMID:24178422

Murthy, B N; Singh, R P; Saxena, P K

1996-02-01

90

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

PubMed

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

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

2009-05-01

91

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

PubMed

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

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

2013-06-01

92

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

PubMed Central

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

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

2013-01-01

93

Stimulation of Daucus carota somatic embryogenesis by inhibitors of ethylene synthesis: cobalt and nickel  

Microsoft Academic Search

The effects of Co2+ and Ni2+ on ethylene production and somatic embryogenesis by carrot (Daucus carota L.) cell cultures were studied. At concentrations of 10 µM to 50 µM, CoCl2 effectively inhibited ethylene production by embryogenic cultures and significantly stimulated somatic embryogenesis. The observed increase of embryo number was proportional to the inhibition level of ethylene production. However, CoCl2 had

J. P. Roustan; A. Latche; J. Fallot

1989-01-01

94

Temporal Regulation of Somatic Embryogenesis by Adjusting Cellular Polyamine Content in Eggplant1  

PubMed Central

Four critical stages of embryogenesis, including callus induction, cellular acquisition of morphogenetic competence, expression of embryogenic program, and development and maturation of somatic embryos during somatic embryogenesis from leaf discs of eggplant (Solanum melongena L.), were identified by scanning electron microscopy. Temporal changes in arginine decarboxylase (ADC) activity and polyamines (PAs) during critical stages of embryogenesis revealed that high levels of PAs (especially putrescine [PUT]), due to higher ADC activity in discs from the apical region (with high embryogenic capacity) than from the basal region of the leaf (with poor embryogenic capacity), were correlated with differential embryogenesis response. Kinetic studies of the up- and down-regulation of embryogenesis revealed that PUT and difluoromethylarginine pretreatments were most effective before the onset of embryogenesis. Basal discs pretreated with PUT for 4 to 7 d showed improved embryogenesis that was comparable to apical discs. PA content at various critical steps in embryogenesis from basal discs were found to be comparable to that of apical discs following adjustments of cellular PA content by PUT. In contrast, pretreatment of apical discs with difluoromethylarginine for 3 d significantly reduced ADC activity, cellular PA content, and embryogenesis to levels that were comparable to basal discs. Discs from the basal region of leaves treated with PUT for 3 d during the identified stages of embryogenesis improved their embryogenic potential. PMID:9490762

Singh Yadav, Jitender; Venkat Rajam, Manchikatla

1998-01-01

95

Polyamine biosynthesis during somatic embryogenesis in interior spruce ( Picea glauca x Picea engelmannii complex)  

Microsoft Academic Search

Putrescine, spermidine, and spermine levels during somatic embryogenesis of interior spruce (Picea glauca x Picea engelmannii complex) were quantified On abscisic acid supplemented growth medium putrescine and spermidine levels increased two-fold coinciding with maturation of the early somatic embryos to globular embryos. Polyclonal antibodies raised against Escherichia coli arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), following affinity purification specifically recognized

Vindhya Amarasinghe; Rajwinder Dhami; John E. Carlson

1996-01-01

96

Developmental pathway of somatic embryogenesis in Picea abies as revealed by time-lapse tracking  

Microsoft Academic Search

of stage I proembryogenic masses by unequal division of embryogenic cells with dense cytoplasm is the pre- Several coniferous species can be propagated via vailing process. Once somatic embryos have formed, somatic embryogenesis. This is a useful method for their further development to mature forms requires clonal propagation, but it can also be used for studying abscisic acid and shares

Lada H. Filonova; Peter V. Bozhkov; Sara von Arnold

2000-01-01

97

Optimization of somatic embryogenesis and embryo germination in soybean  

Microsoft Academic Search

Summary  Somatic embryos of soybean [Glycine max (L.) Merr.] are induced on immature cotyledons explanted onto a medium containing moderately high levels of auxin. Germinability\\u000a of embryos is related to morphologic normality, and both are reduced by excessive exposure to auxin during the induction process.\\u000a Shoot meristem development was improved by reducing exposure of cotyledonary explants from 30 to 10 to

W. A. Parrott; G. Dryden; S. Vogt; D. F. Hildebrand; G. B. Collins; E. G. Williams

1988-01-01

98

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

PubMed

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

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

2000-01-01

99

Somatic embryogenesis in cotton (Gossypium) I. Effects of source of explant and hormone regime  

Microsoft Academic Search

Optimal media for induction of somatic embryogenesis from mature and immature tissues ofG. hirsutum L. cv Coker 312 were determined. Explants of three-day-old seedlings form somatic embryos in 100% of cultures when treated with 0.1 mg\\/1 2,4-dichlorophenoxyacetic acid plus 0.5 mg\\/1 kinetin. Mature tissues are more recalcitrant than immature tissues and formed somatic embryos on a limited number of hormone

Norma L. Trolinder; J. R. Goodin

1988-01-01

100

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

Microsoft Academic Search

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

Jean-Vincent Escalant; Claude Teisson; François Cote

1994-01-01

101

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

Microsoft Academic Search

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

Tammy Estabrooks; Robin Browne; Zhongmin Dong

2007-01-01

102

Effects of light quality on somatic embryogenesis in Araujia sericifera.  

PubMed

The effects of photoperiod, light quality and end-of-day (EOD) phytochrome photoconversion on somatic embryogenesis (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

2001-03-01

103

Somatic embryogenesis and plant regeneration in myrtle (Myrtaceae)  

Microsoft Academic Search

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

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

1999-01-01

104

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

Microsoft Academic Search

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

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

1994-01-01

105

ReproducedfromCropScience.PublishedbyCropScienceSocietyofAmerica.Allcopyrightsreserved. Screening Multiple Soybean Cultivars (MG 00 to MG VIII) for Somatic Embryogenesis  

E-print Network

Multiple Soybean Cultivars (MG 00 to MG VIII) for Somatic Embryogenesis Following Agrobacterium. The transformation potential of multi- types for somatic embryogenesis (Parrott et al., 1989;ple soybean cultivars on a nonselective veloped via Agrobacterium-mediated transforma- medium, high induction of somatic embryogenesis

Korban, Schuyler S.

106

Induction of direct somatic embryogenesis and plant regeneration in pepper (Capsicum annuum L.).  

PubMed

Pepper (cv. New Mexico - 6 and Rajur Hirapur) plants were regenerated from immature zygotic embryos via direct somatic embryogenesis. 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 ?M), thidiazuron (10 ?M) and a high concentration of sucrose (6-10%). The best response was observed on MS medium containing 2,4-D (9 ?M), coconut water (10%) and high sucrose (8%). The entire process of induction and maturation of the embryos was completed on the same medium. Histological examination indicated that secondary embryogenesis also occurred directly from the primary somatic embryos. Differentiation of embryos was nonsynchronous, and some embryos were swollen and distorted with fasciation. More than 70% of the mature normal somatic embryos germinated readily on MS medium containing GA3 or TDZ, alone and in combination, and following transfer to pots developed into normal plants. PMID:24178468

Binzel, M L; Sankhla, N; Joshi, S; Sankhla, D

1996-03-01

107

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

PubMed Central

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

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

2014-01-01

108

Somatic Embryogenesis and Plant Regeneration from Two Recalcitrant Genotypes of Gossypium hirsutum L  

Microsoft Academic Search

An improved protocol has been developed for somatic embryogenesis and plant regeneration of recalcitrant cotton cultivars. High callus frequencies and embryogenic tissue were developed in MSB medium supplemented with gradient concentrations of KT and 2,4-D, their concentration decreasing from 0.1 to 0.01 mg L?1. Somatic embryos were successfully incubated in 1\\/2 macronutrient MSB suspension supplemented with 0.5 g L?1 glutamine

Yan-xia WANG; Xing-fen WANG; Zhi-ying MA; Gui-yin ZHANG; Gai-ying HAN

2006-01-01

109

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

Microsoft Academic Search

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

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

1987-01-01

110

A High-Efficiency Direct Somatic Embryogenesis System for Strawberry (Fragaria x ananassa Duch.) Cultivar Chandler  

Microsoft Academic Search

A high-efficiency, reproducible somatic embryogenesis system for strawberry cultivar Chandler was developed. Thirty-one somatic embryos per explant (max no.) were recorded in leaf discs which were cultured on medium containing MS salts + B5 vitamins + 2% glucose + 4.0 mg l -1 TDZ (Thidiazuron) and incubated at 10 ± 1 şC under darkness for one week followed by three

Amjad M. Husaini; Samina Aquil; Mukhtar Bhat; Tabassum Qadri; Malik Zainul Abdin

111

Mechanisms of somatic embryogenesis in cell cultures: Physiology, biochemistry, and molecular biology  

Microsoft Academic Search

Summary  One of the most characteristic cell functions in plants is totipotency. Somatic embryogenesis can be regarded as a model system\\u000a for the investigation of mechanisms of totipotency, because a high frequency and synchronous embryogenic system from single\\u000a somatic cells has been established in carrot suspension cultures. Four phases are recognized in this process, and several\\u000a molecular markers, viz. polypeptides, mRNAs,

A. Komamine; R. Kawahara; M. Matsumoto; S. Sunabori; T. Toya; A. Fujiwara; M. Tsukahara; J. Smith; M. Ito; H. Fukuda; K. Nomura; T. Fujimura

1992-01-01

112

Optimisation of somatic embryogenesis in fourteen cultivars of sweet potato [Ipomoea batatas (L.) Lam.  

Microsoft Academic Search

Culture procedures have been developed to facilitate the induction and maintenance of somatic embryogenic tissues in 14 out\\u000a of 16 tested cultivars of sweet potato [Ipomoea batatas (L.) Lam]. Both the size of the axillary bud explant and the type of auxin were found to be critical for the successful induction\\u000a of somatic embryogenesis. Of the five auxins screened 2,4-dichlorophenoxyacetic

S. Al-Mazrooei; M. H. Bhatti; G. G. Henshaw; N. J. Taylor; D. Blakesley

1997-01-01

113

Effects of carbohydrate addition on the induction of somatic embryogenesis in Hevea brasiliensis  

Microsoft Academic Search

The effect of different carbohydrates was tested on early somatic embryogenesis 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

1999-01-01

114

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

Microsoft Academic Search

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

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

2011-01-01

115

Comparative proteomic analysis of early somatic and zygotic embryogenesis in Theobroma cacao L.  

PubMed

Somatic embryogenesis 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 somatic embryogenesis in cacao are discussed. PMID:23178419

Noah, Alexandre Mboene; Niemenak, Nicolas; Sunderhaus, Stephanie; Haase, Christin; Omokolo, Denis Ndoumou; Winkelmann, Traud; Braun, Hans-Peter

2013-01-14

116

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

PubMed

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

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

2012-10-01

117

Somatic embryogenesis and organogenesis from cryopreserved shoot tips of Lilium Oriental hybrid ‘Siberia’  

Technology Transfer Automated Retrieval System (TEKTRAN)

Somatic embryogenesis and organogenesis were achieved from cryopreserved shoot tips of Lilium Oriental hybrid ‘Siberia’. Shoot tips (1.5-2 mm) were excised from adventitious shoots that were regenerated from basal leaf segments. Precultured shoot tips were then treated with MS containing 0.4 M sucro...

118

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

Microsoft Academic Search

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

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

1997-01-01

119

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

PubMed Central

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

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

2003-01-01

120

A temporary immersion system improves in vitro regeneration of peach palm through secondary somatic embryogenesis  

PubMed Central

Background and Aims Secondary somatic embryogenesis has been postulated to occur during induction of peach palm somatic embryogenesis. In the present study this morphogenetic pathway is described and a protocol for the establishment of cycling cultures using a temporary immersion system (TIS) is presented. Methods Zygotic embryos were used as explants, and induction of somatic embryogenesis and plantlet growth were compared in TIS and solid culture medium. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to describe in vitro morphogenesis and accompany morpho-histological alterations during culture. Key Results The development of secondary somatic embryos occurs early during the induction of primary somatic embryos. Secondary somatic embryos were observed to develop continually in culture, resulting in non-synchronized development of these somatic embryos. Using these somatic embryos as explants allowed development of cycling cultures. Somatic embryos had high embryogenic potential (65·8 ± 3·0 to 86·2 ± 5·0 %) over the period tested. The use of a TIS greatly improved the number of somatic embryos obtained, as well as subsequent plantlet growth. Histological analyses showed that starch accumulation precedes the development of somatic embryos, and that these cells presented high nucleus/cytoplasm ratios and high mitotic indices, as evidenced by DAPI staining. Morphological and SEM observations revealed clusters of somatic embryos on one part of the explants, while other parts grew further, resulting in callus tissue. A multicellular origin of the secondary somatic embryos is hypothesized. Cells in the vicinity of callus accumulated large amounts of phenolic substances in their vacuoles. TEM revealed that these cells are metabolically very active, with the presence of numerous mitochondria and Golgi apparatuses. Light microscopy and TEM of the embryogenic sector revealed cells with numerous amyloplasts, large nuclei and nucleoli, and numerous plasmodesmata. Plantlets were obtained and after 3 months in culture their growth was significantly better in TIS than on solid culture medium. However, during acclimatization the survival rate of TIS-grown plantlets was lower. Conclusions The present study confirms the occurrence of secondary somatic embryos in peach palm and describes a feasible protocol for regeneration of peach palm in vitro. Further optimizations include the use of explants obtained from adult palms and improvement of somatic embryo conversion rates. PMID:21355009

Steinmacher, D. A.; Guerra, M. P.; Saare-Surminski, K.; Lieberei, R.

2011-01-01

121

Alfalfa embryo production in airlift vessels via direct somatic embryogenesis  

Microsoft Academic Search

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

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

1994-01-01

122

Somatic embryogenesis and plantlet regeneration in the soybean Glycine max  

Microsoft Academic Search

A tissue culture procedure for the regeneration of somatic embryos and plantlets from somatic cells of the soybean Glycine max is described. Bean pods of soybean cv. TGM119 were immersed in liquid nitrogen for 20 minutes. Young embryos were excised from the immature seeds and cultured to form calli. Calli grown from the young embryos were incubated in liquid culture

B. J. Li; W. H. R. Langridge; A. A. Szalay

1985-01-01

123

Plant CellReports (1992)11:122-125 Repetitive somatic embryogenesis from peanut cultures in liquid medium  

E-print Network

Plant CellReports (1992)11:122-125 Repetitive somatic embryogenesis from peanut cultures in liquid, the somatic embryos produced massesof secondaryand tertiary embryoswhich continuedto proliferatefollowing somaticembryogenesisfor plant regeneration. Explants giving rise to somatic " ' .~. D D T\\..~h~~ Plant Cell Reports

Parrott, Wayne

124

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

PubMed Central

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

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

2015-01-01

125

Identification of novel genes potentially involved in somatic embryogenesis in chicory (Cichorium intybus L.)  

PubMed Central

Background In our laboratory we use cultured chicory (Cichorium intybus) explants as a model to investigate cell reactivation and somatic embryogenesis 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 somatic embryogenesis (SE), whereas C15 is a non-responsive genotype (non-embryogenic) and is unable to undergo SE. Previous studies [1] showed that the use of the ?-D-glucosyl Yariv reagent (?-GlcY) that specifically binds arabinogalactan-proteins (AGPs) blocked somatic embryo production in chicory root explants. This observation indicates that ?-GlcY is a useful tool for investigating somatic embryogenesis (SE) in chicory. In addition, a putative AGP (DT212818) encoding gene was previously found to be significantly up-regulated in the embryogenic K59 chicory genotype as compared to the non-embryogenic C15 genotype suggesting that this AGP could be involved in chicory re-differentiation [2]. In order to improve our understanding of the molecular and cellular regulation underlying SE in chicory, we undertook a detailed cytological study of cell reactivation events in K59 and C15 genotypes, and used microarray profiling to compare gene expression in these 2 genotypes. In addition we also used ?-GlcY to block SE in order to identify genes potentially involved in this process. Results Microscopy confirmed that only the K59, but not the C15 genotype underwent complete cell reactivation leading to SE formation. ?-GlcY-treatment of explants blocked in vitro SE induction, but not cell reactivation, and induced cell wall modifications. Microarray analyses revealed that 78 genes were differentially expressed between induced K59 and C15 genotypes. The expression profiles of 19 genes were modified by ?-GlcY-treatment. Eight genes were both differentially expressed between K59 and C15 genotypes during SE induction and transcriptionally affected by ?-GlcY-treatment: AGP (DT212818), 26 S proteasome AAA ATPase subunit 6 (RPT6), remorin (REM), metallothionein-1 (MT1), two non-specific lipid transfer proteins genes (SDI-9 and DEA1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase), and snakin 2 (SN2). These results suggest that the 8 genes, including the previously-identified AGP gene (DT212818), could be involved in cell fate determination events leading to SE commitment in chicory. Conclusion The use of two different chicory genotypes differing in their responsiveness to SE induction, together with ?-GlcY-treatment represented an efficient tool to discriminate cell reactivation from the SE morphogenetic pathway. Such an approach, together with microarray analyses, permitted us to identify several putative key genes related to the SE morphogenetic pathway in chicory. PMID:20565992

2010-01-01

126

Extensive Modulation of the Transcription Factor Transcriptome during Somatic Embryogenesis in Arabidopsis thaliana  

PubMed Central

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

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

2013-01-01

127

Regeneration of Solanum nigrum by Somatic Embryogenesis, Involving Frog Egg-Like Body, a Novel Structure  

PubMed Central

A new protocol was established for the regeneration of Solanum nigrum by frog egg-like bodies (FELBs), which are novel somatic embryogenesis (SE) structures induced from the root, stem, and leaf explants. The root, stem, and leaf explants (93.33%, 85.10%, and 100.00%, respectively) were induced to form special embryonic calli on Murashige and Skoog (MS) medium containing 1.0 mg/L 2,4-dichlorophenoxyacetic acid, under dark condition. Further, special embryonic calli from the root, stem, and leaf explants (86.97%, 83.30%, and 99.47%, respectively) were developed into FELBs. Plantlets of FELBs from the three explants were induced in vitro on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine and 0.1 mg/L gibberellic acid, and 100.00% plantlet induction rates were noted. However, plantlet induction in vivo on MS medium supplemented with 20 mg/L thidiazuron showed rates of 38.63%, 15.63%, and 61.30% for the root, stem, and leaf explants, respectively, which were lower than those of the in vitro culture. Morphological and histological analyses of FELBs at different development stages revealed that they are a novel type of SE structure that developed from the mesophyll (leaf) or cortex (stem and root) cells of S. nigrum. PMID:24896090

Xu, Kedong; Chang, Yunxia; Liu, Kun; Wang, Feige; Liu, Zhongyuan; Zhang, Ting; Li, Tong; Zhang, Yi; Zhang, Fuli; Zhang, Ju; Wang, Yan; Niu, Wei; Jia, Shuzhao; Xie, Hengchang; Tan, Guangxuan; Li, Chengwei

2014-01-01

128

Developmental Localization and Methylesterification of Pectin Epitopes during Somatic Embryogenesis of Banana (Musa spp. AAA)  

PubMed Central

Background The plant cell walls play an important role in somatic embryogenesis 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 Findings Developmental localization of pectic homogalacturonan (HG) epitopes and the (1?4)-?-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment. Conclusions/Significance These data suggest that both low- and highly-methyl-esterified HG epitopes are developmentally regulated in diverse embryogenic stages during somatic embryogenesis. This study provides new information about pectin composition, HG methyl-esterification and developmental localization of pectin epitopes during somatic embryogenesis of banana. PMID:21826225

Xu, Chunxiang; Zhao, Lu; Pan, Xiao; Šamaj, Jozef

2011-01-01

129

Role of genetic background in somatic embryogenesis in Medicago  

Microsoft Academic Search

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

Daniel C. W. Brown; Atanas Atanassov

1985-01-01

130

Somatic embryogenesis and plant regeneration in cotton ( Gossypium hirsutum L.)  

Microsoft Academic Search

Tissue culture methods for improvement of cotton has lagged seriously compared to other major crops. A method for regeneration of cotton which includes a morphogenetically competent cell suspension was needed to facilitate selection of stress-resistant variants and gene manipulation. Preliminary screening of eight strains of Gossypium hirsutum L. for embryogenic potential resulted in the production of somatic embryos in all

Norma L. Trolinder; J. R. Goodin

1987-01-01

131

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

PubMed Central

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

Zhou, Chenguang; Liu, Likun; Li, Chenghao

2014-01-01

132

Somatic embryogenesis on Thin Cell Layers of a C 4 species, Digitaria sanguinalis (L.) Scop  

Microsoft Academic Search

Somatic embryogenesis was obtained from transverse thin cell layers (tTCLs) of Digitaria sanguinalis. tTCLs (0.2 - 0.4mm thick,\\u000a 1mm in diameter) were excised from 4-week-old seedlings and placed onto Murashige and Skoog media supplemented with a varying\\u000a concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) (from 1 µM to 100 µM) and sucrose (from 3% to 24%). Somatic embryos\\u000a were obtained in the

Bui Van Le; Do My Nghieng Thao; C. Gendy; J. Vidal; K. Tran Thanh Van

1997-01-01

133

Induction of somatic embryogenesis in leaf-derived callus of Vicia narbonensis L.  

PubMed

A method for the induction of somatic embryogenesis in callus cultures, using explants from mature leaves of Vicia narbonensis L., is described. Callus developed on a solid medium (Murashige and Skoog 1962), which was supplemented with low concentrations of picloram and benzylaminopurine. Subsequent culture was carried out in different liquid media (culture length four months). The gradual reduction of auxin and cytokinin concentrations, and the addition of glutamine and pyridoxal·HCl were favourable. Somatic embryos appeared on solid media without phytohormones. PMID:24233222

Albrecht, C; Kohlenbach, H W

1989-05-01

134

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

PubMed

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

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

2012-07-01

135

Screening of diploid Medicago sativa germplasm for somatic embryogenesis  

Microsoft Academic Search

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

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

1985-01-01

136

Somatic embryogenesis, maturation and DNA transfer in Pinus  

E-print Network

NPT NS PCR psl 2, 4 dichlorophenoxyacettc acid promoter gene in cauliflower mosaic virus having a sedimentation coefficient of 35S cis-trans abscisic acid benzyladenine cauhflower mosaic virus chloramphenicol acetyltransferase casein... containing 9. 0 pM 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 4. 4 )tM benzyladenine (BA). Cell-lines were categorized mto two main groups based on morphology, those being (1) solar/polar structured somatic embryos and (2) undeveloped with a few loosely...

Marek, Kimberly Ann

1994-01-01

137

Induction of somatic embryogenesis and embryo development in Rumex acetosella L  

Microsoft Academic Search

Axillary buds of the dioecious plant Rumex acetosella L. were isolated and cultured in vitro. The callus tissue which developed at the basal parts of the explants displayed a high capacity for shoot formation. This morphogenetic pattern was predominant on Murashige and Skoog (MS) medium supplemented with 2% sucrose, 2.2 mgl-1 benzylaminopurine and 0.17 mgl-1 indole-3-acetic acid. Somatic embryogenesis was

Ljubinka ?ulafi?; SneŽana Budimir; Radmila Vuji?i?; Mirjana Neškovi?

1987-01-01

138

Optimization of biotin and thiamine requirements for somatic embryogenesis of date palm ( Phoenix dactylifera L.)  

Microsoft Academic Search

Summary  This study was conducted to examine the effect of biotin and thiamine concentrations on callus growth and somatic embryogenesis\\u000a of date palm (Phoenix dactylifera L.). Embryogenic callus derived from offshoot tip explants was cultured on hormone-free MS medium containing biotin at 0,\\u000a 0.1, 1, or 2 mg l?1 combined with thiamine at 0.1, 0.5, 2, or 5 mg l?1. Embryogenic

Jameel M. Al-Khayri

2001-01-01

139

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

Microsoft Academic Search

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

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

140

Chromatin reorganization and endogenous auxin\\/cytokinin dynamic activity during somatic embryogenesis of cultured cotton cell  

Microsoft Academic Search

We conducted a systematic assessment and comparative study on the biochemical and cellular characteristics of cultured cotton\\u000a cells during the entire process of somatic embryogenesis (SE). All staged cultures were widely investigated in this assay.\\u000a Cell and tissue ectogenesis manipulation combined with flow cytometry (FCM) was employed to cellular study during the whole\\u000a totipotency process of dedifferentiation and redifferentiation. We

Fanchang Zeng; Xianlong Zhang; Shuangxia Jin; Lei Cheng; Shaoguang Liang; Lisong Hu; Xiaoping Guo; Yichun Nie; Jinglin Cao

2007-01-01

141

Improvement of somatic embryogenesis in Hevea brasiliensis (Müll. Arg.) using the temporary immersion technique  

Microsoft Academic Search

Summary  A culture procedure using temporary immersion in a liquid medium was tested for somatic embryogenesis of Hevea brasiliensis (Mll. Arg.). Embryogenic callus was placed under regeneration conditions, either on a gelled medium (Phytagel, Sigma, St.\\u000a Louis, MO) or in a container designed for temporary immersion. The latter technique has some advantages over the use of a\\u000a gelled medium during both

H. Etienne; M. Lartaud; N. Michaux-Ferriére; M. P. Carron; M. Berthouly; C. Teisson

1997-01-01

142

Inheritance of somatic embryogenesis using leaf petioles as explants in upland cotton  

Microsoft Academic Search

Somatic embryogenesis (SE) is a critical step leading to plant regeneration in tissue culture of many plant species. The objective\\u000a of the present study was to analyze the inheritance of SE in cotton (Gossypium hirsutum L.) using leaf petioles as explants. A high embryogenic callus (HEC)—producing line, W10, was selected by petiole callus\\u000a culture from a commercial Chinese cotton cultivar

Chaojun Zhang; Shuxun Yu; Shuli Fan; Jinfa Zhang; Fuguang Li

143

Plant regeneration in Stone pine ( Pinus pinea L.) by somatic embryogenesis  

Microsoft Academic Search

Regeneration of plants by somatic embryogenesis (SE) was achieved in Stone pine (Pinus pinea), one of the most characteristic tree species of the Mediterranean ecosystem. The initial explants were megagametophytes\\u000a containing zygotic embryos from five selected half-sib families collected at different dates over 2 consecutive years. Rates\\u000a of extrusion and initiation of SE differed in both years. However, qualitative patterns

E. Carneros; C. Celestino; K. Klimaszewska; Y.-S. Park; M. Toribio; J. M. Bonga

2009-01-01

144

Plantlet production through high frequency somatic embryogenesis in long term cultures of Eucalyptus citriodora  

Microsoft Academic Search

A highly embryogenic culture ofEucalyptus citriodora was obtained by repetitive embryogenesis from somatic embryos cultured in the dark on a medium containing 500 mg\\/l each of glutamine and casein hydrolysate, 30 g\\/l of sucrose and 5 mg\\/l of 1-napthaleneacetic acid. Cultures retained morphogenetic ability for upto 36 months when maintained at 27°C by subculture at intervals of 4–5 weeks. The

E. M. Muralidharan; P. K. Gupta; A. F. Mascarenhas

1989-01-01

145

Somatic embryogenesis and plant regeneration from embryogenic callus of soybean, Glycine max L  

Microsoft Academic Search

During induction of somatic embryogenesis from immature embryos of soybean, a smooth-shiny and a rough callus were obtained. The smooth-shiny type developed from callus derived from cotyledonary tissue and cultured on media containing 10 mg\\/l 2,4-D. The rough type was derived from immature embryos, cotyledons, hypocotyls and hypocotyl segments from germinated seedlings on a medium containing various growth regulators. Plants

T. D. Ghazi; H. V. Cheema; M. W. Nabors

1986-01-01

146

Regeneration of Medicago truncatula from tissue culture: increased somatic embryogenesis using explants from regenerated plants  

Microsoft Academic Search

Plant regeneration has been achieved by somatic embryogenesis in Medicago truncatula Gaertn. (barrel medic) c.v. Jemalong, an annual legume species. Regenerated plants were obtained from cultured leaf tissue explants on a four-step modified B5 basal medium. Induction of embryo formation occurred on a medium containing 10 µM NAA and 10 µM BAP, and embryo maturation was promoted after transfer to

K. E. Nolan; R. J. Rose; J. R. Gorst

1989-01-01

147

Effect of light quality and culture medium on somatic embryogenesis of Agave tequilana Weber var. Azul  

Microsoft Academic Search

Somatic embryogenesis in Agave tequilana Weber var. Azul was affected by the interaction between the light regimes applied during the induction phase and the expression\\u000a phase. When embryogenic calli was exposed to white or red light during the expression phase, an average of two germinated\\u000a embryos per explant was obtained regardless of the light treatment used for callus induction. Conversely,

Araceli Rodríguez-Sahagún; Gustavo Acevedo-Hernández; José M. Rodríguez-Domínguez; Benjamín Rodríguez-Garay; Jesús Cervantes-Martínez; Osvaldo A. Castellanos-Hernández

2011-01-01

148

Tissue culture of saffron (Crocus sativus L.): Somatic embryogenesis and shoot regeneration  

Microsoft Academic Search

Callus was initiated from meristematic regions of corms of Crocus sativus L. on Murashige and Skoog's (1962) medium (MS) supplemented with 2,4?dichlorophenoxyacetic acid (2 mg\\/1) and kinetin (0.5 mg\\/1). Somatic embryogenesis was obtained on transfer of callus to MS medium supplemented with indole?3?acetic acid (2 mg\\/1), kinetin (2 mg\\/1) and ascorbic acid (100 mg\\/1). The globular embryos on 1\\/2 strength

P. S. George; Sujata Visvanath; G. A. Ravishankar; L. V. Venkataraman

1992-01-01

149

Somatic embryogenesis in immature cotyledons of Manchurian ash (Fraxinus mandshurica Rupr.)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Somatic embryogenesis 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 ...

150

Screening of diploid Medicago sativa germplasm for somatic embryogenesis.  

PubMed

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

Meijer, E G; Brown, D C

1985-10-01

151

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

PubMed

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 hypocotyl of the embryos began after 2-3 weeks. Three types of calli were recovered: (a) globular, (b) light green-compact, (c) white mucilaginous. Only the white mucilaginous calli were embryogenic. The globular and light green-compact calli never become embryogenic, even after several subcultures. The development of somatic embryos was accomplished on half-strength macro-elements of NSIII medium containing 1 ?M ?-naphthaleneacetic acid, 1 ?M abscisic acid, and 3% sucrose. The addition of 10(-7) M buthionine sulfoximine to the medium increased the development of somatic embryos by three fold. These results suggest that there is a great potential for increasing the frequency and development of somatic embryos in P. abies. Careful selection of the genotype and modification of the culture medium is required. PMID:24232267

Jain, S M; Newton, R J; Soltes, E J

1988-10-01

152

Genetic transformation via somatic embryogenesis to establish herbicide-resistant opium poppy.  

PubMed

A reliable genetic transformation protocol via somatic embryogenesis has been developed for the production of fertile, herbicide-resistant opium poppy plants. Transformation was mediated by Agrobacterium tumefaciens using the pCAMBIA3301 vector, which harbors the phosphinothricin acetyltransferase (pat) gene driven by a tandem repeat of the cauliflower mosaic virus (CaMV) 35S promoter and the beta-glucuronidase (gus) structural gene driven by a single copy of the CaMV 35S promoter between left- and right-border sequences. Co-cultivation of explants and A. tumefaciens was performed in the presence of 50 microM ATP and 50 microM MgCl(2). Root explants pre-cultured on callus induction medium were used for transformation. Herbicide-resistant, proliferating callus was obtained from explants on a medium containing both 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA). Globular embryogenic callus, induced by removal of the BA from the medium, was placed on a hormone-free medium to form somatic embryos, which were converted to plantlets under specific culture conditions. Plantlets with roots were transferred to soil, allowed to mature and set seed. Both pat and gus gene transcripts, and PAT and GUS enzyme activities were detected in the transgenic lines tested. Histochemical localization of GUS activity in T(1) opium poppy plants revealed transgene expression in most tissues of all plant organs. The protocol required 8-12 months to establish transgenic T(1) seed stocks and was developed using a commercial opium poppy cultivar that produces high levels of pharmaceutical alkaloids. PMID:18057938

Facchini, Peter J; Loukanina, Natalia; Blanche, Vincent

2008-04-01

153

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

Microsoft Academic Search

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

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

1991-01-01

154

A specific role for spermidine in the initiation phase of somatic embryogenesis in Panax ginseng CA Meyer  

Microsoft Academic Search

Somatic embryogenesis 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

2002-01-01

155

An efficient method for production of diploid Cantaloupe Charentais Melon ( Cucumis melo L. var. cantalupensis) by somatic embryogenesis  

Microsoft Academic Search

This paper describes a system of regeneration that allows somatic embryo formation at high frequency from mature cotyledon explants of Cucumis melo L. var. cantalupensis (cv. Védrantais). Several different growth factors, environmental conditions and carbohydrate sources were analysed in order to improve somatic embryogenesis in this cultivar. Best conditions lead to the definition of a two step protocol including a

Monique Guis; Alain Latché; Jean-Claude Pech; Jean-Paul Roustan

1997-01-01

156

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

Microsoft Academic Search

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

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

2001-01-01

157

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

PubMed

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

Capuana, Maurizio

2013-01-01

158

Polyamine biosynthesis during somatic embryogenesis in interior spruce (Picea glauca x Picea engelmannii complex).  

PubMed

Putrescine, spermidine, and spermine levels during somatic embryogenesis of interior spruce (Picea glauca x Picea engelmannii complex) were quantified On abscisic acid supplemented growth medium putrescine and spermidine levels increased two-fold coinciding with maturation of the early somatic embryos to globular embryos. Polyclonal antibodies raised against Escherichia coli arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), following affinity purification specifically recognized spruce ADC and ODC, which corresponded to 85kD and 65kD bands on western blots of total protein extracts from embryogenic masses, Immunoassays using these antibodies showed increased ADC levels corresponding to embryo maturation while ODC levels remained the same. From these results it is concluded that polyamines are involved in the maturation of somatic embryos of interior spruce. PMID:24178460

Amarasinghe, V; Dhami, R; Carlson, J E

1996-03-01

159

Somatic embryogenesis and plant regeneration from immature embryos of western larch.  

PubMed

Somatic embryogenesis was initiated from immature embryos of western larch (Larix occidentalis Nutt.) on media containing 2,4-dichlorophenoxyacetic acid and N6- benzyladenine. The effects of explant type and ammonium nitrate and glutamine concentrations on initiation were tested. Although 21-93% of explants rendered cultures in various experiments, only 3% yielded sustainable embryogenic lines. Excised embryos at the early cotyledonary stage were optimal for initiation. Maturation of somatic embryos was promoted by abscisic acid. Response to abscisic acid concentrations and duration of exposure to abscisic acid varied with genotype. Maximal results were obtained with 0.025 ? M abscisic acid for 1 to 2 weeks followed by individual culture on medium without growth regulators. Mature somatic embryos developed into shoots with roots. Plantlets have been established in peat. PMID:24201537

Thompson, R G; von Aderkas, P

1992-07-01

160

Influence of micropropagation through somatic embryogenesis on somaclonal variation in coffee (Coffea arabica) : assessment of variations at the phenotypical, cytological, genetic and epigenetic level.  

E-print Network

??Influence of micropropagation through somatic embryogenesis on somaclonal variation in coffee (Coffea arabica): assessment of variations at the phenotypical, cytological, genetic and epigenetic level Somaclonal… (more)

Bobadilla Landey, Roberto

2013-01-01

161

Arabinogalactan proteins and the extracellular matrix surface network during peach palm somatic embryogenesis.  

PubMed

Somatic embryogenesis has been described in peach palm as a reliable method for its in vitro multiplication and conservation. In this study, we evaluated the possible role of arabinogalactan proteins (AGPs) during this morphogenetic pathway. The presence of Yariv reagent, a synthesized chemical antibody that specifically binds AGP molecules, affected somatic embryos and callus development rate, but no effect was observed on fresh weight increment. This substance also had profound effects on embryo morphology: somatic embryos presented loose cells in the protoderm and no signs of polarization could be observed. To better evaluate the role of AGPs, analyses of specific monoclonal antibodies (MAbs) against different AGP epitopes revealed a specific pattern of distribution for each epitope. MAb JIM13 had differential expression and showed intense signal on the embryogenic sector and some immediately adjacent layers. MAb JIM7 against pectin recognized cell walls and a specific layer over the developing somatic embryo, as well as over the shoot meristem region of mature somatic embryos. This corresponds to an extracellular matrix surface network (ECMSN) associated with the development of somatic embryos and closely related to the expression of MAb JIM13. Scanning electron microscopy confirmed the presence of an ECMSN covering a specific group of cells and ultra-structural analyses revealed that the ECMSN had lipophilic substances. PMID:22574975

Steinmacher, Douglas A; Saare-Surminski, Katja; Lieberei, Reinhard

2012-11-01

162

Improved protocol for somatic embryogenesis and calcium alginate encapsulation in Anethum graveolens L.: a medicinal herb.  

PubMed

An improved procedure has been developed for efficient somatic embryogenesis in Anethum graveolens. Green friable embryogenic callus was obtained from hypocotyl segments on medium augmented with 2,4-dichlorophenoxyacetic acid (2,4-D). The highest embryogenic callus induction frequency of 87 % was obtained on Murashige and Skoog (MS) medium containing 1.13 ?M 2,4-D. At lower concentration of 2,4-D (0.34 ?M) callus turned dark in color and slow growing. Embryogenic cultures (76 %) responded with a mean number of 43 globular and 18 heart stage embryos. Somatic embryo maturation and subsequent conversion into plantlets took place on MS lacking growth regulators. Maximum number of somatic embryos developed on MS medium was 128.3 (per flask) and a plantlet conversion of 82 % was observed. Calcium alginate beads were produced by encapsulating somatic embryos. Highest percent germination (83 %) was observed on 0.8 % agar solidified MS medium with the plantlets acquiring an average length of 2.1 cm. Encapsulated somatic embryos could be stored at 4 °C up to 60 days with a conversion frequency of 49.3 %. Highest protein and proline content has been observed in embryogenic callus with small globular embryos. During morphological differentiation of the somatic embryos, changes in the antioxidant enzymatic system were observed. Superoxide dismutase (SOD) activity increased during initial stages and decreased catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities were detected. PMID:24974170

Dhir, Richa; Shekhawat, G S; Alam, Afroz

2014-08-01

163

Genetic improvement of the somatic embryogenesis and regeneration in soybean and transformation of the improved breeding lines  

Microsoft Academic Search

Somatic embryos of soybean [Glycine max (L.) Merrill] have been used to generate transgenic plants by particle bombardment. The induction and proliferation of somatic\\u000a embryos from immature cotyledons are dependent on the genotype of the cultivar. Whereas somatic embryogenesis and plant regeneration\\u000a are inefficient in most cultivars, they are efficient in the cultivar Jack. We previously established a breeding line,

Yoichi Kita; Keito Nishizawa; Masakazu Takahashi; Masahiko Kitayama; Masao Ishimoto

2007-01-01

164

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

PubMed

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

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

2010-11-01

165

Protocol for Callus Induction and Somatic Embryogenesis in Moso Bamboo  

PubMed Central

Moso bamboo [Phyllostachys heterocycla var. pubescens (Mazel ex J. Houz.) Ohwi] is one of the most important forest crops in China and the rest of Asia. Although many sympodial bamboo tissue culture protocols have been established, there is no protocol available for plantlet regeneration as indicated by callus induction for monopodial bamboos, such as Moso bamboo. In the present report, embryogenic callus induction, embryoid development, and germination were established for Moso bamboo from zygotic seed embryos. Callus was initiated from zygotic embryos after 10–20 d culture on MS media supplemented with 4.0 mg/L 2, 4-D and 0.1 mg/L zeatin (ZT). About 50% of the explants produced calli, and nearly 15% of the calli were found to be embryogenic in nature. These embryogenic calli can be subcultured for proliferation in the Murashige and Skoog media (MS) supplemented with 0.5–2.0 mg/L 2, 4-D. These calli were found to have maintained their capacity for regeneration even after one year of subculture. The viable somatic embryoids regenerated in medium containing 5.0–7.0 mg/L ZT. Nearly 5% of the calli were found capable of regenerating into plantlets directly in MS medium containing 5.0–7.0 mg/L ZT. Root growth was more pronounced when the plantlets were transferred to medium containing 2.0 mg/L NAA. After 30 days of subculture, the plantlets were transferred to a greenhouse. PMID:24349159

Wu, Xiao-Li; Gu, Xiao-Ping

2013-01-01

166

Effects of type of explant and age, plant growth regulators and medium strength on somatic embryogenesis and plant regeneration in Eucalyptus camaldulensis  

Microsoft Academic Search

Plant regeneration was achieved through direct and indirect somatic embryogenesis 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

M. G. Prakash; K. Gurumurthi

2010-01-01

167

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

PubMed

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

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

2014-09-01

168

THE REGENERATION OF BLACK GRAMA PLANTS VIA SOMATIC EMBRYOGENESIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seeds of Bouteloua eropida, (Torr.) Torr. were surface disinfested and germinated on a carbon mineral rich medium. Callus was initiated from embryonic shoots excised from the roots on auxin supplemented medium. After callus multiplication, embryos were induced from callus. They developed into nor...

169

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

Microsoft Academic Search

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

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

1997-01-01

170

Secondary somatic embryogenesis and plant regeneration in myrtle (Myrtus communis L.)  

Microsoft Academic Search

Immature seeds, as well as hypocotyls and cotyledons excised from seedlings of Myrtus communis L., were cultured on media containing half-strength Murashige and Skoog macronutrients (MS\\/2) with combinations of auxins\\u000a and cytokinins, in order to study their morphogenetic competence. Somatic embryogenesis was obtained from cotyledons, hypocotyls\\u000a and 2-month-old immature seeds with 0.1 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D). The percentage of explants

R. Parra; J. B. Amo-Marco

1998-01-01

171

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

PubMed Central

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

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

2013-01-01

172

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

PubMed

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

Ayil-Gutiérrez, Benajmín; Galaz-Ávalos, Rosa; Peńa-Cabrera, Eduardo; Loyola-Vargas, Victor

2013-11-01

173

The Arabidopsis somatic embryogenesis receptor kinase 1 gene is expressed in developing ovules and embryos and enhances embryogenic competence in culture  

Microsoft Academic Search

We report here the isolation of the Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (AtSERK1) gene and we demonstrate its role during establishment of somatic embryogenesis in culture. The AtSERK1 gene is highly expressed during embryogenic cell formation in culture and during early embryogenesis. The AtSERK1 gene is first expressed in planta during megasporogenesis in the nucleus of developing ovules, in

V. Hecht; J. P. Vielle-Calzada; M. V. Hartog; E. D. L. Schmidt; K. Boutilier; U. Grossniklaus; Vries de S. C

2001-01-01

174

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

NASA Technical Reports Server (NTRS)

The objectives of this study were to determine the effects of low temperature (4 degrees C) preincubation on somatic embryogenesis from orchardgrass (Dactylis glomerata L.) leaf cultures and to relate these effects to ethylene emanation during the preincubation and incubation periods. Experiments were also conducted with an ethylene biosynthesis inhibitor aminooxyacetic acid (AOA). Segments from the innermost two leaves were cultured on SH medium with 30 micromoles dicamba at 4 degrees C for 1 to 7 d before transfer to 21 degrees C. Results from a paired design showed that the embryogenic response of leaf segments preincubated at 4 degrees C was equal or superior to nonpreincubated leaves at all time periods. Ethylene emanation was decreased during the low temperature incubation. Transfer of leaf segments from 4 degrees C to 21 degrees C was accompanied by a burst of ethylene which rose to control levels within 30 min. AOA at 20 and 40 micromoles decreased ethylene emanation but did not stimulate the embryogenic response. We conclude that the stimulation of somatic embryogenesis by low temperature is probably due to factors other than suppression of ethylene biosynthesis.

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

1994-01-01

175

GhAGL15s, preferentially expressed during somatic embryogenesis, promote embryogenic callus formation in cotton (Gossypium hirsutum L.).  

PubMed

Somatic embryogenesis is a useful tool for gene transfer and propagation of plants. AGAMOUS-LIKE15 (AGL15) promotes somatic embryogenesis in many plant species. In this study, three homologous AGL15 genes were isolated from Gossypium hirsutum L., namely GhAGL15-1, GhAGL15-3, and GhAGL15-4. Their putative proteins contained a highly conserved MADS-box DNA-binding domain and a less conserved K domain. Phylogenetic analysis suggested that the three GhAGL15s clustered most closely with AGL15 proteins in other plants. Subcellular location analyses revealed that three GhAGL15s were localized in the nucleus. Furthermore, their expression levels increased following embryogenic callus induction, but sharply decreased during the embryoid stage. GhAGL15-1 and GhAGL15-3 were significantly induced by 2,4-D and kinetin, whereas GhAGL15-4 was only responsive to 2,4-D treatment. Over-expression of the three GhAGL15s in cotton callus improved callus quality and significantly increased the embryogenic callus formation rate, while GhAGL15-4 had the highest positive effect on the embryogenic callus formation rate (an increase from 38.1 to 65.2%). These results suggest that over-expression of GhAGL15s enhances embryogenic potential of transgenic calli. Therefore, spatiotemporal manipulation of GhAGL15s expression may prove valuable in improving cotton transformation efficiency. PMID:24833045

Yang, Zuoren; Li, Changfeng; Wang, Ye; Zhang, Chaojun; Wu, Zhixia; Zhang, Xueyan; Liu, Chuanliang; Li, Fuguang

2014-10-01

176

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

PubMed

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

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

1999-12-01

177

Induction by thidiazuron of somatic embryogenesis in intact seedlings of peanut  

Microsoft Academic Search

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

Praveen K. Saxena; Kamal A. Malik; R. Gill

1992-01-01

178

Morphogenesis in callus tissue of Medicago sativa : The role of ammonium ion in somatic embryogenesis  

Microsoft Academic Search

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

K. A. Walker; S. J. Sato

1981-01-01

179

Characterization and expression analysis of somatic embryogenesis receptor-like kinase genes from Phalaenopsis.  

PubMed

Somatic embryogenesis receptor-like kinase (SERK) genes have been found to be involved in the somatic embryogenesis of several plant species. We identified and characterized 5 PhSERK genes in the Phalaenopsis orchid. The amino acid sequences of PhSERKs and other SERK proteins are highly conserved, with the highest homology observed in the leucine-rich repeat-receptor-like kinase domain. All 5 PhSERKs were expressed in all Phalaenopsis organs examined (root, leaf, shoot apical meristem, and flower), with the strongest expression, particularly for PhSERK1 and 3, in the shoot apical meristem of mature plants. Expression of all PhSERKs was downregulated during early floral bud development and was upregulated gradually until the semi-open flower stage was reached. All 5 PhSERKs were expressed during both seed germination and protocorm-like-body (PLB) development. In germinated seeds, quantitative real-time PCR revealed upregulation of all PhSERKs except PhSERK4 at 1 week and downregulation after 4 weeks. The 5 PhSERKs were differentially expressed in the early stage of PLB development and maintained substantial levels during PLB formation, with PhSERK1 and 5 upregulated 1 week after culture and PhSERK2, 3, and 4 downregulated over this period. Because physical wounding of PLB stimulates secondary PLB formation, the PhSERK5 expression peak at week 3 coincided with visible and fully developed secondary PLBs. PhSERK5 may be important in PLB induction and subsequent development. Our PhSERK expression analysis revealed that these genes have a broad role during orchid plant development. PMID:25526190

Huang, Y W; Tsai, Y J; Chen, F C

2014-01-01

180

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

PubMed

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

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

2010-04-01

181

Somatic embryogenesis in quite a direct way in cultures of mesophyll protoplasts of Brassica napus L  

Microsoft Academic Search

Somatic embryos and plantlets have been obtained in quite a direct way from mesophyll protoplasts isolated from androgenetic plants of two cultivars (“Loras” and “Tower”) of Brassica napus. The procedure consists of four steps. Proembryos were induced in a medium supplemented with a cytokinin and an auxin at comparatively high concentrations. They developed to mature embryos when the auxin was

Liang-cai Li; Hans Willy Kohlenbach

1982-01-01

182

Enhanced somatic embryogenesis and plant regeneration in leaf explant cultures of Ostericum koreanum on medium of varying pH  

Microsoft Academic Search

The leaf explants of Ostericum koreanum were cultured on MS medium supplemented with 5.37 µM NAA and 0.44 µM BA and did not need transfer to growth regulator–free medium for somatic embryogenesis. The pH level of medium dropped after autoclaving and at the beginning of explant culture, then rose back to the normal pH level of medium. The low pH

Duck-Yee Cho; Eun-Kyong Lee; Sukchan Lee; Won-Il Chung; Woong-Young Soh

2003-01-01

183

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

Microsoft Academic Search

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

A. S. T. Immonen

1996-01-01

184

Clonal propagation of Trifolium Pratense, T. Resupinatum and T. Subterraneum by direct somatic embryogenesis on cultured immature embryos  

Microsoft Academic Search

Direct somatic embryogenesis 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

G. Maheswaran; E. G. Williams

1986-01-01

185

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

Microsoft Academic Search

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

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

1993-01-01

186

Initiation of somatic embryogenesis in Pinus banksiana , P. strobus , P . pinaster , and P. sylvestris at three laboratoriesin Canada and France  

Microsoft Academic Search

During 2002–2004, three laboratories in Canada and France collaborated to improve initiation of somatic embryogenesis (SE) in jack pine (Pinus banksiana Lamb.), eastern white pine (P. strobus L.), maritime pine (P. pinaster Ait.), and Scots pine (P.?sylvestris L.), giving particular attention to the effects of (1) N-(2-chloro-4-pyridyl)-N?-phenylurea (CPPU) versus various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and benzyladenine (BA), (2) differences

Y. S. Park; M. A. Lelu-Walter; L. Harvengt; J. F. Trontin; I. MacEacheron; K. Klimaszewska; J. M. Bonga

2006-01-01

187

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

Microsoft Academic Search

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

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

1998-01-01

188

agronomie: plant genetics and breeding Regulation of somatic embryo development  

E-print Network

, the system offers unique opportunities to study embryology. Somatic embryogenesis has been induced in many to the methods based on bud differentiation. The advantages with somatic embryogenesis are that the somaticagronomie: plant genetics and breeding Regulation of somatic embryo development in Norway spruce

Boyer, Edmond

189

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

PubMed

Somatic embryogenesis (SE) offers vast potential for the clonal propagation of high-value roses. However, some recalcitrant cultivars unresponsive to commonly employed SE-inducing agents and low induction rates currently hinder the commercialization of SE technology in rose. Rose SE technology requires improvement before it can be implemented as a production system on a commercial scale. In the present work, we assessed 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), a synthetic auxin not previously tested in rose, for its effectiveness to induce SE in the rose cultivar "Livin' Easy" (Rosa sp.). We ran a parallel comparison to the commonly used 2,4-dichlorophenoxyacetic acid (2,4-D). We tested each auxin with two different basal media: Murashige and Skoog (MS) basal medium and woody plant medium (WPM). MS medium resulted in somatic embryo production, whereas WPM did not. 2,4,5-T induced SE over a greater concentration range than 2,4-D's and resulted in significantly greater embryo yields. 2,4,5-T at a concentration of 10 or 25 microM was better for embrygenic tissue initiation than 2,4,5-T at 5 microM. Further embryo development occurred when the tissue was transferred to plant growth regulator (PGR) free medium or media with 40% the original auxin concentration. However, the PGR-free medium resulted in a high percentage of abnormal embryos (32.31%) compared to the media containing auxins. Upon transfer to germination medium, somatic embryos successfully converted into plantlets at rates ranging from 33.3 to 95.2%, depending on treatment. Survival rates 3 months ex vitro averaged 14.0 and 55.6% for 2,4-D- and 2,4,5-T-derived plantlets, respectively. Recurrent SE was observed in 60.2% of the plantlets growing on germination medium. This study is the first report of SE in the commercially valuable rose cultivar 'Livin' Easy' (Rosa sp.) and a suitable methodology was developed for SE of this rose cultivar. PMID:16972095

Estabrooks, Tammy; Browne, Robin; Dong, Zhongmin

2007-02-01

190

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

PubMed Central

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

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

2012-01-01

191

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

PubMed Central

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

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

2007-01-01

192

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

Microsoft Academic Search

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

Patricia Gutičrrez pesce; Eddo Rugini

2004-01-01

193

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

Microsoft Academic Search

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

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

1996-01-01

194

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

Microsoft Academic Search

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

Sui-Wen Hou; Jing-Fen Jia

2004-01-01

195

Direct somatic embryogenesis and plantlet regeneration from cotyledonary leaves of safflower  

Microsoft Academic Search

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

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

1995-01-01

196

Involvement of peroxidase activity in developing somatic embryos of Medicago arborea L. Identification of an isozyme peroxidase as biochemical marker of somatic embryogenesis.  

PubMed

The legume Medicago arborea L. is very interesting as regards the regeneration of marginal arid soils. The problem is that it does not have a good germinative yield. It was therefore decided to regenerate via somatic embryogenesis and find a marker of embryogenic potential. In this study, peroxidase activity was evaluated in non-embryogenic and embryogenic calli from M. arborea L. A decrease in soluble peroxidase activity is observed in its embryonic calli at the time at which the somatic embryos begin to appear. This activity is always lower in embryonic calli than in non-embryonic ones (unlike what happens in the case of wall-bound peroxidases). These results suggest that peroxidases can be considered to be enzymes involved in somatic embryogenesis in M. arborea. In addition, isozyme analyses were carried out on protein extracts using polyacrylamide gel electrophoresis. The band called P5 was detected only in embryogenic cultures at very early stages of development. This band was digested with trypsin and analyzed using linear ion trap (LTQ) mass spectrometer. In P5 isoform a peroxidase-L-ascorbate peroxidase was identified. It can be used as a marker that allows the identification of embryological potential. PMID:24331422

Gallego, Piedad; Martin, Luisa; Blazquez, Antonio; Guerra, Hilario; Villalobos, Nieves

2014-01-15

197

Annotation of Differentially Expressed Genes in the Somatic Embryogenesis of Musa and Their Location in the Banana Genome  

PubMed Central

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis 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 somatic embryogenesis of Musa. PMID:24027442

Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-GraciaMedrano, Rosa Maria

2013-01-01

198

[Role of exogenous Ca2+ in the somatic embryogenesis of Lycium barbarum L].  

PubMed

In this study, Embryogenic and non-embryogenic calli were separately obtained by cultivation of leaf segments on MS medium containing and not containing 2,4-D 0.2 mg/L. The calli were transferred to an 2,4-D-free MS medium containing different concentrations of (45)Ca(2+) and EGTA cultured, and microscopic examination of tissue sliced, gamma-ray energy spectrum analysis, ELISA and two-dimensional polyacrylamide-gel electrophoresis were used to study the relation between changes in Ca(2+) concentration and protein composition changes during somatic embryogenesis. The results showed that: (1) Calli of dedifferentiation were obtained by cultivating in the inductive medium (MS+2,4-D 0.2 mg/L) and then transferred to the 2,4-D-free (MS) differentiation medium. After cultivating, the large number of embryogenic cells divided and somatic embryogenic calli (EC) were formed; embryogenic cell differentiation and somatic embryo ware not formed when the dedifferentiation calli, which were cultivated in the inductive medium without 2,4-D, ware transferred to the cultivating of differentiation, so calli were called non-embryogenic calli (NEC). (2) SE frequency of EC was rised with exogenous Ca(2+) concentration was going up, and adding peak value (70.5% to 74.5%) when Ca(2+)concentration was from 0.8 to 1.6 mmol/L, then SE frequency was dropped markedly with Ca(2+) concentration was farther increasing. Formation of meristematic cell aggregates of NEC was also enhanced when exogenous Ca(2+) concentration was from 0.8 to 1.6 mmol/L. (3) After adding EGTA, which was Ca(2+) antagonist, SE frequency was dropped markedly, and SE frequency was fallen along with increased of EGTA concentration. When EGTA concentration went up to 1.2 micromol/L, SE frequency dropped to 5%, and the formation of meristematic cell aggregates on NEC was inhibited. (4) When 2 microCi (45)Ca(2+)/mL was added, the uptake of (45)Ca(2+) by EC and NEC was different, two uptake peaks of (45)Ca(2+)appeared in EC at the embryogenic cell differentiation of stage, and the uptake of (45)Ca(2+) of EC was 4-5 times higher than that of NEC, and the uptake frequency of (45)Ca(2+) improved from 54.1% to 74.5%. The uptake of (45)Ca(2+) by NEC during development not only was lower than that by EC but also there were no such marked peak as those with EC. (5) The CaM content examined by ELISA was increased markedly at multi-cellular embryo and globular embryoid stage of EC. After adding Ca(2+), the CaM content increased significantly, the CaM content of EC was 2-3 times that of NEC. (6) The IEF/SDS-PAGE results showed that the numbers and amount of protein components were widely different between the two kinds of callus with different morphogenesis patterns, the number of proteins of EC had more components than those of NEC. The largest differences protein species presented with Ca(2+) ware added, the more proteins presented on the range of molecular weight was from 43 kD to 66 kD and pI values was from 4.0 to 7.0. PMID:15599021

Xing, Geng-Mei; Jing, Ru-Fang; Li, Shan; Zhang, Xia; Xu, Hai-Xia; Cui, Kai-Rong; Yu, Chun-Hong; Wang, Ya-Fu

2004-06-01

199

High frequency plant regeneration system for Nymphoides coreana via somatic embryogenesis from zygotic embryo-derived embryogenic cell suspension cultures  

Microsoft Academic Search

Culture conditions were established for high frequency plant regeneration via somatic embryogenesis from cell suspension cultures\\u000a of Nymphoides coreana. Zygotic embryos formed pale-yellow globular structures and calluses at a frequency of 85.6% when cultured on half-strength\\u000a Murashige and Skoog (MS) medium supplemented with 0.3 mg l?1 of 2,4-D. However, the frequency of pale-yellow globular structures and white callus formation decreased slightly with

Myung Jin Oh; Hye Ryun Na; Hong-Keun Choi; Jang Ryol Liu; Suk Weon Kim

2010-01-01

200

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

PubMed

Somaclonal variation during interior spruce (Picea glauca engelmannii complex) somatic embryogenesis was evaluated using culture morphology and isozyme analysis. Genotype-specific abscisic acid-dependent developmental profiles and isozyme patterns were similar for subclone and parent line embryogenic cultures and cotyledonary somatic embryos. Extensive analysis of fifteen hundred subclone embryos of one genotype revealed no isozyme pattern variation. Initiation of embryogenic cultures was dependent on the developmental stage of the explant although cultures derived from different stages were morphologically similar. The embryogenic cultures initiated from interior spruce embryos show a high degree of genetic stability in that the morphological behavior and isozyme phenotype were always consistent with that of the explant genotype. These results support the conclusion that this culture system is appropriate for clonal propagation of interior spruce. PMID:24221739

Eastman, P A; Webster, F B; Pitel, J A; Roberts, D R

1991-10-01

201

Effect of plumule and radicle on somatic embryogenesis in the cultures of ginseng zygotic embryos  

Microsoft Academic Search

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

Yong Eui Choi; Woong Young Soh

1996-01-01

202

Initiation and maintenance of long term somatic embryogenesis from anthers and ovaries of Vitis longii ‘Microsperma’  

Microsoft Academic Search

Anthers and ovaries of Vitis longii ‘Microsperma’ produced embryogenic callus when cultured on solidified Murashige and Skoog medium with 5µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1µM benzyladenine (BA). The initial callus was short-lived. However, long-term embryogenesis from callus was maintained through serial transfers by careful selection of clustered embryos with subtending callus. Alternatively, long term culture maintenance was through secondary embryogenesis

D. J. Gray; J. A. Mortensen

1987-01-01

203

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

PubMed Central

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

2011-01-01

204

Effect of 2,4-D and 4-CPPU on somatic embryogenesis from stigma and style transverse thin cell layers of Citrus  

Microsoft Academic Search

Callus induction, somatic embryogenesis and plant regeneration were obtained in lemon [Citrus limon (L.) Burm. cv `Femminello'] and sweet orange [C. sinensis (L.) Osb. cv `Washington Navel GS'] from cultures of stigma and style transverse thin cell layer explants [(t)TCLs]. Explants were cultured on 16 different media, based on the nutrients and vitamins of Murashige and Tucker medium (MT) supplemented

Stefania Fiore; Fabio De Pasquale; Francesco Carimi; Maurizio Sajeva

2002-01-01

205

Characterization and expression analysis of SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK) genes in sexual and apomictic Paspalum notatum.  

PubMed

The SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) gene plays a fundamental role in somatic embryogenesis of angiosperms, and is associated with apomixis in Poa pratensis. The objective of this work was to isolate, characterize and analyze the expression patterns of SERK genes in apomictic and sexual genotypes of Paspalum notatum. A conserved 200-bp gene fragment was amplified from genomic DNA with heterologous primers, and used to initiate a chromosomal walking strategy for cloning the complete sequence. This procedure allowed the isolation of two members of the P. notatum SERK family; PnSERK1, which is similar to PpSERK1, and PnSERK2, which is similar to ZmSERK2 and AtSERK1. Phylogenetic analyses indicated that PnSERK1 and PnSERK2 represent paralogous sequences. Southern-blot hybridization indicated the presence of at least three copies of SERK genes in the species. qRT-PCR analyses revealed that PnSERK2 was expressed at significantly higher levels than PnSERK1 in roots, leaves, reproductive tissues and embryogenic calli. Moreover, in situ hybridization experiments revealed that PnSERK2 displayed a spatially and chronologically altered expression pattern in reproductive organs of the apomictic genotype with respect to the sexual one. PnSERK2 is expressed in nucellar cells of the apomictic genotype at meiosis, but only in the megaspore mother cell in the sexual genotype. Therefore, apomixis onset in P. notatum seems to be correlated with the expression of PnSERK2 in nucellar tissue. PMID:24146222

Podio, Maricel; Felitti, Silvina Andrea; Siena, Lorena Adelina; Delgado, Luciana; Mancini, Micaela; Seijo, José Guillermo; González, Ana María; Pessino, Silvina Claudia; Ortiz, Juan Pablo A

2014-03-01

206

NORMALIZING SWEET ORANGE (C. SINENSIS (L.) OSBECK) SOMATIC EMBRYOGENESIS WITH SEMIPERMEABLE MEMBRANES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Development of citrus somatic embryos initiated from embryogenic callus generally results in abnormal morphologies during growth and development. Shoots can be regenerated by organogenesis from these abnormal structures, excised and rooted to recover plants. To normalize development, glycerol-indu...

207

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

Microsoft Academic Search

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

Wayne A. Parrott; Matthew A. Bailey

1993-01-01

208

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

PubMed Central

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

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

2001-01-01

209

Arabidopsis LEAFY COTYLEDON2 induces maturation traits and auxin activity: Implications for  

E-print Network

by LEC2, a B3 domain transcription factor, that may underlie its ability to promote somatic embryogenesis phase. The rele- vance of these changes to the ability of LEC2 to promote somatic embryogenesis of differentiated cells of the sporophyte can be induced to undergo somatic embryogenesis, microspores can

Goldberg, Robert B.

210

Establishment of embryonic cultures and somatic embryogenesis in callus culture of guggul-Commiphora wightii (Arnott.) Bhandari.  

PubMed

Somatic embryogenesis in callus cultures of Commiphora wightii (Arnott.) Bhandari was achieved. Though the frequency of explants producing embryonic culture was low, immature zygotic embryos were the only suitable explants to produce embryonic callus after reciprocal transfers on media containing 2,4,5-trichlorophenoxy acetic acid (0.1 mgl(-1)) and kinetin (0.1 mgl(-1)) or devoid of growth regulators. All other media failed to produce embryonic callus. Embryonic cells were small, densely filled with cytoplasm and isodiametric as compared to non-embryonic cells, which were large, elongated and vacuolated. Maximum growth of embryonic callus was recorded on modified MS medium (MS-2 medium) supplemented with BA (0.25 mgl(-1)) and IBA (0.1 mgl(-1)). MS-2 salts supported higher growth of callus as compared to tissues grown on B5 medium containing same concentrations of plant growth regulators. Exogenous medium nutrients had no effect on somatic embryo development whereas plant growth regulators had little effect. Asynchronously growing embryos formed plantlets regularly which were successfully transferred to the field conditions. PMID:15267139

Kumar, Sandeep; Suri, S S; Sonie, K C; Ramawat, K G

2003-01-01

211

Effect of inhibition of biosynthesis of phenylpropanoids on sessile oak somatic embryogenesis  

Microsoft Academic Search

The inhibition of phenylpropanoid biosynthesis by 2-aminoindan-2-phosphonic acid (AIP) in embryogenic culture of sessile oak (Quercus petraea (Matt.) Liebl.) was associated with a strong reduction of the amount of cinnamic acid derivatives, decline in lignin content and changes in the proportion of different types of somatic embryos. The decrease in the level of phenylpropanoid lignin precursors after AIP application decreased

Milena Cvikrová; Jana Malá; Marie Hrubcová; Josef Eder; Jerzy Zo?; Ivana Machá?ková

2003-01-01

212

Somatic embryogenesis from grapevine cells. I-Improvement of embryo development by changes in culture conditions  

Microsoft Academic Search

In conventional culture conditions without auxin, somatic embryos arising from suspension cultures of grapevine rootstock 41B (Vitis vinifera cv. Chasselas x Vitis berlandieri) are arrested at the heart stage of development. Starting from indications that inhibitors excreted in the culture medium could be responsible for this arrest, new culture conditions based on daily subculturing embryos in fresh medium have been

Pierre Coutos-Thevenot; Isabelle Goebel-Tourand; Marie-Claude Mauro; Jean-Pierre Jouanneaul; Michel Boulay; Alain Deloire; Jean Guern

1992-01-01

213

Yield performance and bean quality traits of cacao propagated by somatic embryogenesis and grafting  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twelve cacao (Theobroma cacao) clones propagated by grafting and rooted cuttings of somatic embryo-derived plants were grown on an Ultisol soil at Corozal, Puerto Rico and evaluated for six years under intensive management. Year, variety, the year x variety and propagation treatment x variety intera...

214

An Unusual Abscisic Acid and Gibberellic Acid Synergism Increases Somatic Embryogenesis, Facilitates Its Genetic Analysis and Improves Transformation in Medicago truncatula  

PubMed Central

Somatic embryogenesis (SE) can be readily induced in leaf explants of the Jemalong 2HA genotype of the model legume Medicago truncatula by auxin and cytokinin, but rarely in wild-type Jemalong. Gibberellic acid (GA), a hormone not included in the medium, appears to act in Arabidopsis as a repressor of the embryonic state such that low ABA (abscisic acid): GA ratios will inhibit SE. It was important to evaluate the GA effect in M. truncatula in order to formulate generic SE mechanisms, given the Arabidopsis information. It was surprising to find that low ABA:GA ratios in M. truncatula acted synergistically to stimulate SE. The unusual synergism between GA and ABA in inducing SE has utility in improving SE for regeneration and transformation in M. truncatula. Expression of genes previously shown to be important in M. truncatula SE was not increased. In investigating genes previously studied in GA investigations of Arabidopsis SE, there was increased expression of GA2ox and decreased expression of PICKLE, a negative regulator of SE in Arabidopsis. We suggest that in M. truncatula there are different ABA:GA ratios required for down-regulating the PICKLE gene, a repressor of the embryonic state. In M. truncatula it is a low ABA:GA ratio while in Arabidopsis it is a high ABA:GA ratio. In different species the expression of key genes is probably related to differences in how the hormone networks optimise their expression. PMID:24937316

Nolan, Kim E.; Song, Youhong; Liao, Siyang; Saeed, Nasir A.; Zhang, Xiyi; Rose, Ray J.

2014-01-01

215

Direct somatic embryogenesis on leaf explants of Oncidium Gower Ramsey and subsequent plant regeneration  

Microsoft Academic Search

Segments taken from young leaves of an orchid (Oncidium Gower Ramsey) produced clusters of somatic embryos directly from epidermal and mesophyll cells of leaf tips and wound surfaces\\u000a without an intervening callus within 1 month when cultured on a GelriteTM-gelled 1\\/2-MS basal medium supplemented with a low dosage (0.3–1?mg\\/l) of thidiazuron. Subculturing of these embryo clusters\\u000a produced more embryos and

J. T. Chen; C. Chang; W. C. Chang

1999-01-01

216

Norway spruce somatic embryogenesis: high-frequency initiation from light-cultured mature embryos  

Microsoft Academic Search

Somatic embryos and rooted plantlets have been regenerated from light-initiated embryogenic callus derived from mature embryos of Picea abies. Under a 16 h photoperiod, mature zygotic embryos were cultured on a modified half-strength Murashige & Skoog medium without NH4NO3 and supplemented with 5 mM glutamine, 4.5 µM N6-benzyladenine and 10.7 µM naphthaleneacetic acid or 10 µM 2,4-dichlorophenoxyacetic acid. White translucent

Shirley A. Verhagen; Steven R. Wann

1989-01-01

217

Improved efficiency of somatic embryogenesis and plant regeneration in tissue cultures of maize ( Zea mays L.)  

Microsoft Academic Search

Immature embryos of eleven cultivars of hybrid maize (Zea mays L.), cultured on 2,4-D-containing nutrient media, showed rapid proliferation of the scutellum and improved efficiency in the formation of embryogenic callus and somatic embryos. High concentrations of sucrose were found to be most favorable for the formation of the embryogenic callus. Embryoids obtained in cultures of all eleven cultivars germinated

C. Lu; V. Vasil; I. K. Vasil

1983-01-01

218

Direct somatic embryogenesis and plant regeneration from leaf, petiole, and stem explants of Golden Pothos  

Microsoft Academic Search

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

Q. Zhang; J. Chen; R. J. Henny

2005-01-01

219

Direct somatic embryogenesis and plant regeneration from leaf, petiole, and stem explants of Golden Pothos.  

PubMed

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

Zhang, Q; Chen, J; Henny, R J

2005-02-01

220

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

Microsoft Academic Search

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

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

2009-01-01

221

RAPDs as an aid to evaluate the genetic integrity of somatic embryogenesis-derived populations of Picea mariana (Mill.) B.S.P  

Microsoft Academic Search

The usefulness of random amplified polymorphic DNA (RAPD) in assessing the genetic stability of somatic embryogenesis-derived populations of black spruce [Picea mariana (Mill.) B.S.P.] was evaluated. Three arbitrary 11-mer primers were successfully used to amplify DNA from both in-vivo and in-vitro material. Twenty-five embryogenic cell lines, additional zygotic embryos and megagametophytes from three controlled crosses involving four selected genotypes of

N. Isabel; L. Tremblay; M. Michaud; F. M. Tremblay; J. Bousquet

1993-01-01

222

Patterns of expression of the JIM4 arabinogalactan-protein epitope in cell cultures and during somatic embryogenesis in Daucus carota L  

Microsoft Academic Search

Spatiotemporal patterns of expression of the cell-surface arabinogalactan-protein epitope defined by monoclonal antibody JIM4 (J.P. Knox et al., 1989, Development 106, 47–56) have been characterized by indirect immunofluorescence during the process of somatic embryogenesis in Daucus carota L. The JIM 4 epitope (J4e) occurred on cells established in culture from hypocotyl explants which appeared to derive, at least in part,

Nicola J. Stacey; Keith Roberts; J. Paul Knox

1990-01-01

223

A Mathematical Model for the Coreceptors SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 and SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE3 in BRASSINOSTEROID INSENSITIVE1-Mediated Signaling[C][W  

PubMed Central

Brassinosteroids (BRs) are key regulators in plant growth and development. The main BR-perceiving receptor in Arabidopsis (Arabidopsis thaliana) is BRASSINOSTEROID INSENSITIVE1 (BRI1). Seedling root growth and hypocotyl elongation can be accurately predicted using a model for BRI1 receptor activity. Genetic evidence shows that non-ligand-binding coreceptors of the SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) family are essential for BRI1 signal transduction. A relatively simple biochemical model based on the properties of SERK loss-of-function alleles explains complex physiological responses of the BRI1-mediated BR pathway. The model uses BRI1-BR occupancy as the central estimated parameter and includes BRI1-SERK interaction based on mass action kinetics and accurately describes wild-type root growth and hypocotyl elongation. Simulation studies suggest that the SERK coreceptors primarily act to increase the magnitude of the BRI1 signal. The model predicts that only a small number of active BRI1-SERK complexes are required to carry out BR signaling at physiological ligand concentration. Finally, when calibrated with single mutants, the model predicts that roots of the serk1serk3 double mutant are almost completely brassinolide (BL) insensitive, while the double mutant hypocotyls remain sensitive. This points to residual BRI1 signaling or to a different coreceptor requirement in shoots. PMID:24072582

van Esse, Wilma; van Mourik, Simon; Albrecht, Catherine; van Leeuwen, Jelle; de Vries, Sacco

2013-01-01

224

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

Microsoft Academic Search

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

J. G. Carman

1988-01-01

225

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

PubMed

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

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

2010-07-01

226

Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells  

Microsoft Academic Search

Somatic cell nuclear transfer allows trans-acting factors present in the mammalian oocyte to reprogram somatic cell nuclei to an undifferentiated state. We show that four factors (OCT4, SOX2, NANOG, and LIN28) are sufficient to reprogram human somatic cells to pluripotent stem cells that exhibit the essential characteristics of embryonic stem (ES) cells. These induced pluripotent human stem cells have normal

Junying Yu; Maxim A. Vodyanik; Kim Smuga-Otto; Jessica Antosiewicz-Bourget; Jennifer L. Frane; Shulan Tian; Jeff Nie; Gudrun A. Jonsdottir; Victor Ruotti; Ron Stewart; Igor I. Slukvin; James A. Thomson

2007-01-01

227

Alterations in the Transcriptome of Soybean in Response to Enhanced Somatic Embryogenesis Promoted by Orthologs of AGAMOUS-Like15 and AGAMOUS-Like181[C][W][OPEN  

PubMed Central

Somatic embryogenesis (SE) is a poorly understood process during which competent cells respond to inducing conditions, allowing the development of somatic embryos. It is important for the regeneration of transgenic plants, including for soybean (Glycine max). We report here that constitutive expression of soybean orthologs of the Arabidopsis (Arabidopsis thaliana) MADS box genes AGAMOUS-Like15 (GmAGL15) and GmAGL18 increased embryogenic competence of explants from these transgenic soybean plants. To understand how GmAGL15 promotes SE, expression studies were performed. Particular genes of interest involved in embryogenesis (ABSCISIC ACID-INSENSITIVE3 and FUSCA3) were found to be directly up-regulated by GmAGL15 by using a combination of quantitative reverse transcription-polymerase chain reaction and chromatin immunoprecipitation. To look more broadly at changes in gene expression in response to GmAGL15, we assessed the transcriptome using the Affymetrix Soybean Genome Array. Interestingly, the gene expression profile of 35Spro:GmAGL15 explants (0 d in culture) was found to resemble nontransgenic tissue that had been induced for SE by being placed on induction medium for 3 d, possibly explaining the more rapid SE development observed on 35Spro:GmAGL15 tissue. In particular, transcripts from genes related to the stress response showed increased transcript accumulation in explants from 35Spro:GmAGL15 tissue. These same genes also showed increased transcript accumulation in response to culturing nontransgenic soybean explants on the medium used to induce SE. Overexpression of GmAGL15 may enhance SE by making the tissue more competent to respond to 2,4-dichlorophenoxyacetic acid induction by differential regulation of genes such as those involved in the stress response, resulting in more rapid and prolific SE. PMID:24481137

Zheng, Qiaolin; Perry, Sharyn E.

2014-01-01

228

Efficient transformation and regeneration of fig (Ficus carica L.) via somatic embryogenesis.  

PubMed

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

2010-01-01

229

Analysis of trace elements during different developmental stages of somatic embryogenesis in Plantago ovata Forssk using energy dispersive X-ray fluorescence.  

PubMed

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. Somatic embryogenesis 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

Saha, Priyanka; Raychaudhuri, Sarmistha Sen; Sudarshan, Mathummal; Chakraborty, Anindita

2010-06-01

230

Somatic Embryogenesis in Peach Palm Using the Thin Cell Layer Technique: Induction, Morpho-histological Aspects and AFLP Analysis of Somaclonal Variation  

PubMed Central

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 somatic embryogenesis 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. PMID:17670751

Steinmacher, D. A.; Krohn, N. G.; Dantas, A. C. M.; Stefenon, V. M.; Clement, C. R.; Guerra, M. P.

2007-01-01

231

New Insights into Somatic Embryogenesis: LEAFY COTYLEDON1, BABY BOOM1 and WUSCHEL-RELATED HOMEOBOX4 Are Epigenetically Regulated in Coffea canephora  

PubMed Central

Plant cells have the capacity to generate a new plant without egg fertilization by a process known as somatic embryogenesis (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. PMID:23977240

Nic-Can, Geovanny I.; López-Torres, Adolfo; Barredo-Pool, Felipe; Wrobel, Kazimierz; Loyola-Vargas, Víctor M.; Rojas-Herrera, Rafael; De-la-Peńa, Clelia

2013-01-01

232

Plant pathology Difference in somatic embryogenetic ability  

E-print Network

was noticed with reference to optimum concentration of NAA required for somatic embryogenesis. Percent and grown to ma- turity. Solanum melongena = egg plant / leaf explant / somatic embryogenesis / genotypic embryogenesis in a num- ber of species have opened the possibility of us- ing somatic embryos as a potential

Boyer, Edmond

233

High frequency shoot organogenesis and somatic embryogenesis in juvenile and adult tissues of seabuckthorn ( Hippophae rhamnoides L.)  

Microsoft Academic Search

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

Sridevy Sriskandarajah; Per-Olof Lundquist

2009-01-01

234

Induction of high-frequency somatic embryogenesis in geranium ( Pelargonium x hortorum Bailey cv Ringo Rose) cotyledonary cultures  

Microsoft Academic Search

The cv Ringo Rose of hybrid seed geranium (Pelargonium x hortorum Bailey), previously shown to be recalcitrant in culture, produced somatic embryos when cotyledonary explants were cultured on regeneration medium containing thidiazuron (TDZ), forchlorfenuron (CPPU), or a combination of indole-3-acetic acid and N6 benzylaminopurine (IAA+BAP). Amendment of the basal medium with TDZ (0.5 µM) was the most effective treatment. Addition

B. N. S. Murthy; R. P. Singh; Praveen K. Saxena

1996-01-01

235

Effect of vitamins and inorganic micronutrients on callus growth and somatic embryogenesis from leaves of chilli pepper  

Microsoft Academic Search

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

2001-01-01

236

Original article Embryogenesis in Quercus petraea  

E-print Network

of the unsteady seed produc- tion. MATERIALS AND METHODS Androgenesis and somatic embryogenesis AnthersOriginal article Embryogenesis in Quercus petraea J Jörgensen Lower Saxony Forest Research; Embryogenesis in Quercus petraea was achieved by culture of zygotic embryos and anthers on modified woody plant

Paris-Sud XI, Université de

237

Somatic embryogenesis, micropropagation and plant regeneration of "Early Mature" walnut trees (Juglans regia) that flower in vitro.  

PubMed

Some walnut trees (Juglans regia L.) originating from central Asia display an early flowering phenotype. These "Early Mature" (EM) trees may produce flowers within months of germination. Secondary flowering waves are also observed within a growing season. Inflorescences may carry male, female and hermaphrodite flowers. Progeny obtained from selected EM trees were cultured in vitro to initiate clonal propagation of these genotypes. Embryogenic lines were established through the culture of immature zygotic embryos. Microshoot lines were obtained from germinated somatic or zygotic embryos. Plants showing EM phenotypes were recovered through direct conversion of somatic embryos or adventitious rooting of microcuttings. During the in vitro propagation phase, flower buds were observed on microshoots after three to six subcultures. Histological analysis showed that most of these flowers were hermaphrodite. In vitro apical buds were used to clone the walnut orthologous cDNAs of the AGAMOUS and APETALA 3 MADS-box genes. Northern blots revealed a preferential expression of both of these homeotic genes in flowers. The results highlight the usefulness of EM lines to study the genetic cues controlling flowering and sexual maturity in woody perennials. PMID:14757582

Breton, Christian; Cornu, Daniel; Chriqui, Dominique; Sauvanet, Annie; Capelli, Pierrette; Germain, Eric; Jay-Allemand, Christian

2004-04-01

238

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

Microsoft Academic Search

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

P. V. Mauri; J. A. Manzanera

2003-01-01

239

Stereocilia displacement induced somatic motility of cochlear outer hair cells.  

PubMed Central

Outer hair cells, isolated from mammalian cochleas, are known to respond to electrical stimulation with elongation or contraction of the cell's cylindrical soma. It is assumed that such shape changes, when driven by the cell's receptor potential in vivo, are a part of the feedback process that underlies cochlear amplification. To date it has not been possible to demonstrate somatic shape changes upon normal mechanical stimulation of the cell--i.e., the deflection of its hair bundle. We show here that mechanically induced hair-bundle deflection produces somatic motility of the cell. Such motility is dependent upon a functioning forward transducer process and disappears upon interference with transduction. The motile response also reflects the hair bundle's known directional sensitivity. This demonstration of mechanically driven motility indicates that the cell may possess capabilities to affect its mechanical environment under control of its own receptor potential and, thereby, participate in a local cochlear feedback process. Images Fig. 1 PMID:8378305

Evans, B N; Dallos, P

1993-01-01

240

Plant regeneration via direct somatic embryogenesis from leaf and petiole explants of Epipremnum aureum 'Marble Queen' and characterization of selected variants  

Microsoft Academic Search

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

2012-01-01

241

Why Somatic Plant Cells Start to form Embryos?  

Microsoft Academic Search

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

Attila Fehér

242

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

Microsoft Academic Search

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

John J. Finer

1987-01-01

243

Somatic Embryogenesis in the Cycadales  

Microsoft Academic Search

\\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,

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

244

Metronidazole induced DNA damage in somatic cells of Drosophila melanogaster.  

PubMed

The standard version of the wing somatic mutation and recombination test (SMART) in Drosophila melanogaster was employed in order to evaluate the genotoxic potential of metronidazole (MTZ) as a function of exposure concentration. MTZ was administered by chronic feeding of 3-day-old larvae with the parenteral solution at 0, 500, 1000 and 2000 ?g/ml until pupation. The marker-heterozygous progeny (mwh+/+flr3) with phenotypically wild-type wings was analyzed. Non significant differences were found between control and each MTZ concentration tested for single small spots (SSS) frequencies. Large single spots (LSS) and twin spots (TS) were significantly increased with the higher dose. MTZ treatments with 1000 and 2000 ?g/ml also significantly increased the frequency of Total spots. These findings suggest that MTZ is genotoxic in the present experimental conditions and induces recombinagenesis and/or gene conversion, two major mechanisms that cause loss of heterocigosity and could play an important role in tumorigenesis and carcinogenesis processes. PMID:23845111

Palermo, Ana María; Mudry, Marta Dolores

2013-07-01

245

Induced DNA damage by dental resin monomers in somatic cells.  

PubMed

The present in vivo study investigated the genotoxicity of four dental resin monomers: triethyleneglycoldimethacrylate (TEGDMA), hydroxyethylmethacrylate (HEMA), urethanedimethacrylate (UDMA) and bisphenol A-glycidylmethacrylate (BisGMA). The Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster was applied to analyse their genotoxicity expressed as homologous mitotic recombination, point and chromosomal mutation. SMART detects the loss of heterozygosity of marker genes expressed phenotypically on the fly's wings. This fruit fly has an extensive genetic homology to mammalians, which makes it a suitable model organism for genotoxic investigations. The present findings provide evidence that the mechanistic basis underlying the genotoxicity of UDMA and TEGDMA is related to homologous recombination and gene/chromosomal mutation. A genotoxic pattern can correspondingly be discerned for both UDMA and TEGDMA: their genotoxicity is attributed respectively to 49% and 44% of mitotic recombination, as well as 51% and 56% of mutational events, including point and chromosomal alterations. The monomer UDMA is 1.6 times more active than TEGDMA to induce mutant clones per treatment unit. BisGMA and HEMA had no statistically significant effect on total spot frequencies - suggesting no genotoxic action in the SMART assay. The clinical significance of these observations has to be interpreted for data obtained in other bioassays. PMID:20041880

Arossi, Guilherme Anziliero; Lehmann, Mauricio; Dihl, Rafael Rodrigues; Reguly, Maria Luiza; de Andrade, Heloisa Helena Rodrigues

2010-02-01

246

CHAPTER 1. GENE EXPRESSION PATTERNS DURING SOMATIC EMBRYO DEVELOPMENT AND  

E-print Network

expression patterns were profiled during somatic embryogenesis in a regeneration- proficient maize hybrid are significantly up or down-regulated during somatic embryogenesis in Hi II maize line regeneration. Although many1 CHAPTER 1. GENE EXPRESSION PATTERNS DURING SOMATIC EMBRYO DEVELOPMENT AND GERMINATION IN MAIZE Hi

Carriquiry, Alicia

247

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

PubMed Central

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

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

2012-01-01

248

LEAFY COTYLEDON2 encodes a B3 domain transcription factor that induces  

E-print Network

induces the formation of somatic embryos and other organ-like structures and often confers embryonic that establishes a cellular environment sufficient to initiate embryo development. Embryogenesis in flowering to withstand desiccation at the final stage of seed development. At the end of embryogenesis, the seed consists

Goldberg, Robert B.

249

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

Microsoft Academic Search

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

Jin-Zhuo Dong; David I. Dunstan

1996-01-01

250

Can Body Condition and Somatic Indices be Used to Evaluate Metal-Induced Stress in Wild Small Mammals?  

E-print Network

Can Body Condition and Somatic Indices be Used to Evaluate Metal-Induced Stress in Wild Small) Can Body Condition and Somatic Indices be Used to Evaluate Metal-Induced Stress in Wild Small Mammals) affect behaviour and physiology of animals. Together, these parameters can create both great inter

Paris-Sud XI, Université de

251

Comparison of Somatic Embryogenesis?derived Coffee (Coffea arabica L.) Plantlets Regenerated in vitro or ex vitro: Morphological, Mineral and Water Characteristics  

PubMed Central

Coffea arabica L. plantlets obtained ex vitro after sowing somatic embryos produced in a bioreactor in horticultural substrate were compared with those obtained in vitro from the same embryo population under conventional culturing conditions on semi?solid media. The intensity and quality of aerial and root system development were compared. Shoot emergence was more efficient in vitro but rooting frequencies were low. In contrast, all ex vitro?regenerated embryos rooted. The cotyledon area of mature embryos produced in a bioreactor positively affected plantlet development when regeneration was carried out ex vitro. Embryos with an intermediate cotyledon area (0·86 cm2) had the highest rates of plant conversion ex vitro (63 %), and also resulted in vigorous plantlets. Mortality was higher in nursery conditions, but better plant development was obtained. The quality of plantlets produced under ex vitro conditions was reflected in better growth of the aerial and root systems, and also by similar morphological, mineral and water status characteristics to seedlings. Unlike roots formed on semi?solid media, those produced in soil were branched, fine (30–50 % had a diameter of less than 0·5 mm) and they bore root hairs. Leaves of plantlets regenerated ex vitro had a histological structure similar to that of seedling leaves, and a lower stomatal density (100 vs. 233 mm–2). Moreover, they were more turgid, as indicated by higher pressure potential (?P) (0·91 vs. 0·30 MPa) and relative water content values (97 vs. 93 %). Furthermore, under in vitro conditions, leaves had larger stomata which were abnormally round and raised. Direct sowing of germinated somatic embryos resulted in the rapid production of vigorous plantlets under ex vitro conditions, whilst removing the need for problematical and costly conventional acclimatization procedures. PMID:12125775

BARRY?ETIENNE, D.; BERTRAND, B.; VASQUEZ, N.; ETIENNE, H.

2002-01-01

252

Organogenesis, embryogenesis, and synthetic seed production in Arnebia euchroma —A critically endangered medicinal plant of the Himalaya  

Microsoft Academic Search

Summary  This is the first report of simultaneous organogenesis and somatic embryogenesis 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 somatic embryogenesis. 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 somatic embryogenesis

Sumit Manjkhola; Uppeandra Dhar; Meena Joshi

2005-01-01

253

Enhanced homologous recombination is induced by alpha-particle radiation in somatic cells of Arabidopsis thaliana  

NASA Astrophysics Data System (ADS)

Almost 9 percent of cosmic rays which strike the earth's atmosphere are alpha particles. As one of the ionizing radiations (IR), its biological effects have been widely studied. However, the plant genomic instability induced by alpha-particle radiation was not largely known. In this research, the Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability induced by alpha-particle radiation (3.3MeV). The pronounced effects of systemic exposure to alpha-particle radiation on the somatic homologous recombination frequency (HRF) were found at different doses. The 10Gy dose of radiation induced the maximal HRF which was 1.9-fold higher than the control. The local radiation of alpha-particle (10Gy) on root also resulted in a 2.5-fold increase of somatic HRF in non-radiated aerial plant, indicating that the signal(s) of genomic instability was transferred to non-radiated parts and initiated their genomic instability. Concurrent treatment of seedlings of Arabidopsis thaliana with alpha-particle and DMSO(ROS scavenger) both in systemic and local radiation signifi- cantly suppressed the somatic HR, indicating that the free radicals produced by alpha-particle radiation took part in the production of signal of genomic instability rather than the signal transfer. Key words: alpha-particle radiation, somatic homologous recombination, genomic instability

Bian, Po; Liu, Ping; Wu, Yuejin

254

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

E-print Network

is in preparation and will be pub- lished elsewhere. Somatic embryogenesis in pistil callus of basket willow (Salix if plants could be propagated via somatic embryogenesis. In order to facilitate identificationSomatic embryos from callus of Salix viminalis L. L. Grönroos, S. von Arnold T. Ericsson Department

Paris-Sud XI, Université de

255

Pine embryogenesis  

PubMed Central

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

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

2009-01-01

256

INTRODUCTION During the course of embryogenesis the potential of cells  

E-print Network

INTRODUCTION During the course of embryogenesis the potential of cells becomes increasingly, visceral and somatic muscle, heart (dorsal) muscle, hemocytes, gonad-sheath cells (gonadal mesoderm, 197-205) and has been proposed to function in a cell-fate choice between fat cell and somatic gonadal

Hoshizaki, Deborah K.

257

Somatic copy-number mosaicism in human skin revealed by induced pluripotent stem cells  

PubMed Central

Reprogramming human somatic cells into induced pluripotent stem cells (iPSCs) has been suspected of causing de novo copy number variations (CNVs)1-4. To explore this issue, we performed a whole-genome and transcriptome analysis of 20 human iPSC lines derived from primary skin fibroblasts of 7 individuals using next-generation sequencing. We find that, on average, an iPSC line manifests two CNVs not apparent in the fibroblasts from which the iPSC was derived. Using qPCR, PCR, and digital droplet PCR (ddPCR), we show that at least 50% of those CNVs are present as low frequency somatic genomic variants in parental fibroblasts (i.e. the fibroblasts from which each corresponding hiPSC line is derived) and are manifested in iPSC colonies due to the colonies’ clonal origin. Hence, reprogramming does not necessarily lead to de novo CNVs in iPSC, since most of line-manifested CNVs reflect somatic mosaicism in the human skin. Moreover, our findings demonstrate that clonal expansion, and iPSC lines in particular, can be used as a discovery tool to reliably detect low frequency CNVs in the tissue of origin. Overall, we estimate that approximately 30% of the fibroblast cells have somatic CNVs in their genomes, suggesting widespread somatic mosaicism in the human body. Our study paves the way to understanding the fundamental question of the extent to which cells of the human body normally acquire structural alterations in their DNA post-zygotically. PMID:23160490

Abyzov, Alexej; Mariani, Jessica; Palejev, Dean; Zhang, Ying; Haney, Michael Seamus; Tomasini, Livia; Ferrandino, Anthony; Belmaker, Lior A. Rosenberg; Szekely, Anna; Wilson, Michael; Kocabas, Arif; Calixto, Nathaniel E.; Grigorenko, Elena L.; Huttner, Anita; Chawarska, Katarzyna; Weissman, Sherman; Urban, Alexander Eckehart; Gerstein, Mark; Vaccarino, Flora M.

2012-01-01

258

Somatic coding mutations in human induced pluripotent stem cells  

PubMed Central

Defined transcription factors can induce epigenetic reprogramming of adult mammalian cells into induced pluripotent stem cells. Although DNA factors are integrated during some reprogramming methods, it is unknown whether the genome remains unchanged at the single nucleotide level. Here we show that 22 human induced pluripotent stem (hiPS) cell lines reprogrammed using five different methods each contained an average of five protein-coding point mutations in the regions sampled (an estimated six protein coding point mutations per exome). The majority of these mutations were non-synonymous, nonsense, or splice variants, and were enriched in genes mutated or having causative effects in cancers. At least half of these reprogramming-associated mutations pre-existed in fibroblast progenitors at low frequencies, while the rest were newly occurring during or after reprogramming. Thus, hiPS cells acquire genetic modifications in addition to epigenetic modifications. Extensive genetic screening should become a standard procedure to ensure hiPS safety before clinical use. PMID:21368825

Gore, Athurva; Li, Zhe; Fung, Ho-Lim; Young, Jessica; Agarwal, Suneet; Antosiewicz-Bourget, Jessica; Canto, Isabel; Giorgetti, Alessandra; Israel, Mason; Kiskinis, Evangelos; Lee, Je-Hyuk; Loh, Yuin-Han; Manos, Philip D.; Montserrat, Nuria; Panopoulos, Athanasia D.; Ruiz, Sergio; Wilbert, Melissa; Yu, Junying; Kirkness, Ewen F.; Belmonte, Juan Carlos Izpisua; Rossi, Derrick J.; Thomson, James; Eggan, Kevin; Daley, George Q.; Goldstein, Lawrence S.B.; Zhang, Kun

2011-01-01

259

The role of double-strand break-induced allelic homologous recombination in somatic plant cells.  

PubMed

During meiosis, homologous recombination occurs between allelic sequences. To evaluate the biological significance of such a pathway in somatic cells, we used transgenic tobacco plants with a restriction site for the rare cutting endonuclease I-SceI within a negative selectable marker gene. These plants were crossed with two tobacco lines containing, in allelic position, either a deletion or an insertion within the marker gene that rendered both marker gene and restriction site inactive. After the double-strand break induction, we selected for repair events resulting in a loss of marker gene function. This loss was mostly due to deletions. We were also able to detect double strand break-induced allelic recombination in which the break was repaired by a faithful copying process from the homologue carrying the shortened transgene. The estimated frequency indicates that homologous recombination in somatic cells between allelic sites appears to occur at the same order of magnitude as between ectopic sites, and is thus far too infrequent to act as major repair pathway. As somatic changes can be transferred to the germ line, the prevalence of intrachromatid rearrangements over allelic recombination might be an indirect prerequisite for the enhanced genome plasticity postulated for plants. PMID:12410807

Gisler, Brigitte; Salomon, Siegfried; Puchta, Holger

2002-11-01

260

Somatic embryogenesis in Canary Island date palm  

Microsoft Academic Search

Zygotic embryo and shoot tip explants of Phoenix canariensis were cultured on MS (1962) basal medium supplemented with 100 µM Picloram and 9.5 µM kinetin or 10.8 µM or 45.25 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 9.8 µM N6-(2-isopentenyl) adenine (2iP). These explants after 12 weeks in darkness at 28 °C, produced embryogenic callus with very compact, pale yellow, nodular structures.

Le Thi Lan Huong; Michela Baiocco; Bao Phan Huy; Bruno Mezzetti; Rodolfo Santilocchi; Pasquale Rosati

1999-01-01

261

Channelrhodopsins of Volvox carteri Are Photochromic Proteins That Are Specifically Expressed in Somatic Cells under Control of Light, Temperature, and the Sex Inducer[C][W  

PubMed Central

Channelrhodopsins are light-gated ion channels involved in the photoresponses of microalgae. Here, we describe the characterization of two channelrhodopsins, Volvox channelrhodopsin-1 (VChR1) and VChR2, from the multicellular green alga Volvox carteri. Both are encoded by nuclear single copy genes and are highly expressed in the small biflagellated somatic cells but not in the asexual reproductive cells (gonidia). Expression of both VChRs increases after cell cleavage and peaks after completion of embryogenesis, when the biosynthesis of the extracellular matrix begins. Likewise, expression of both transcripts increases after addition of the sex-inducer protein, but VChR2 is induced much more than VChR1. The expression of VChR1 is specifically promoted by extended dark periods, and heat stress reduces predominantly VChR1 expression. Expression of both VChRs increased under low light conditions, whereas cold stress and wounding reduced expression. Both VChRs were spectroscopically studied in their purified recombinant forms. VChR2 is similar to the ChR2 counterpart from Chlamydomonas reinhardtii with respect to its absorption maximum (460 nm) and photocycle dynamics. In contrast, VChR1 absorbs maximally at 540 nm at low pH (D540), shifting to 500 nm at high pH (D500). Flash photolysis experiments showed that after light excitation, the D540 dark state bleaches and at least two photoproducts, P600 and P500, are sequentially populated during the photocycle. We hypothesize that VChR2 is a general photoreceptor that is responsible for the avoidance of blue light and might play a key role in sexual development, whereas VChR1 is the main phototaxis photoreceptor under vegetative conditions, as it is more specifically adapted to environmental conditions and the developmental stages of Volvox. PMID:19641026

Kianianmomeni, Arash; Stehfest, Katja; Nematollahi, Ghazaleh; Hegemann, Peter; Hallmann, Armin

2009-01-01

262

Partial Somatic to Stem Cell Transformations Induced By Cell-Permeable Reprogramming Factors  

PubMed Central

The production of pluripotent stem cells (iPSCs) for therapeutic applications will require practical methods to achieve tight temporal and quantitative control of reprogramming factor (RF) expression, while avoiding the mutagenic potential of gene transfer. Toward this end, we have developed cell-permeable RF proteins (CP-RFs) incorporating newly developed macromolecule transduction domains (MTDs). Treatment of human dermal fibroblasts (HDFs) with combinations of cell-permeable OCT4, SOX2, KLF4, CMYC and either NANOG or LIN28 proteins induced the outgrowth of stem cell-like colonies (iSCs). iSC colonies generated with CP-RFs resembled embryonic stem cells with regard to morphology, biomarker expression, and extended capacity for self-renewal, but failed to expand as iPSC or ES cell lines. Partial reprogramming appears to be a common response to protein-based delivery of programming factors into somatic cells. PMID:24618595

Lim, Junghee; Kim, Junghee; Kang, Jinsun; Jo, Daewoong

2014-01-01

263

Partial somatic to stem cell transformations induced by cell-permeable reprogramming factors.  

PubMed

The production of pluripotent stem cells (iPSCs) for therapeutic applications will require practical methods to achieve tight temporal and quantitative control of reprogramming factor (RF) expression, while avoiding the mutagenic potential of gene transfer. Toward this end, we have developed cell-permeable RF proteins (CP-RFs) incorporating newly developed macromolecule transduction domains (MTDs). Treatment of human dermal fibroblasts (HDFs) with combinations of cell-permeable OCT4, SOX2, KLF4, CMYC and either NANOG or LIN28 proteins induced the outgrowth of stem cell-like colonies (iSCs). iSC colonies generated with CP-RFs resembled embryonic stem cells with regard to morphology, biomarker expression, and extended capacity for self-renewal, but failed to expand as iPSC or ES cell lines. Partial reprogramming appears to be a common response to protein-based delivery of programming factors into somatic cells. PMID:24618595

Lim, Junghee; Kim, Junghee; Kang, Jinsun; Jo, Daewoong

2014-01-01

264

Mechanistic and methodological aspects of chemically-induced somatic mutation and recombination in Drosophila melanogaster.  

PubMed

This study presents the analysis of chemically-induced somatic mutations and chromosomal damage in the eye imaginal discs of Drosophila larvae, assayed later as twin (TS) and single light (LS) mosaic spots in the adult eyes. Regarding the question as to what kind of DNA alterations contribute to somatic cell mutagenicity, the approach followed here has been to investigate the possible differences in response between male (hemizygous for an X) and female (homozygous) larvae, rod-X/rod-X versus ring-X/rod-X genotypes and inversion-heterozygotes versus genotypes not carrying an inversion. The systems chosen for this analysis were the white-coral/white (wco/w) and the white+/white (w+/w) eye mosaic system. The principle findings with 12 mutagens of different modes of action are as follows: (1) At least 98% of all TS and LS induced by cisplatin (DDP) in wco/w female larvae and about 95% of those by formaldehyde (FA) appear as the result of recombinogenic activity between the two homologous X-chromosomes. The corresponding estimates for MMS, EMS and ENU are 81%, 73% and 61%, respectively. (2) The long scS1L sc8R inversion, which also contains In(1)dl-49, suppresses induction of TS to 83-93%. There was also a sharp decline in the frequency of LS in inversion heterozygotes for DDP (91%), FA (86%), MMS (52%) and EMS (47%). (3) Ethylnitrosourea (ENU) was the mutagen for which introduction of the inverted chromosome reduced only slightly (23%) the frequency of LS, indicating that the majority of them were somatic mutations (and deletions) at the white locus. (4) In w/RX females heterozygous for a ring-X chromosome, the frequency of LS was only approximately one tenth of that of the control (w+/w) group, after exposure to MMS or DDP. The explanation is that exchange processes involving the ring frequently lead to genetic imbalance with subsequent cell killing. PMID:3116423

Vogel, E W; Zijlstra, J A

1987-10-01

265

The role of Krüppel-like factors in the reprogramming of somatic cells to induced pluripotent stem cells  

PubMed Central

Summary The potential for clinical application of pluripotent embryonic stem cells is immense but hampered by moral and ethical complications. Recent advances in the reprogramming of somatic cells by defined factors to a state that resemble embryonic stem cells have created tremendous excitement in the field. Four factors, Sox2, Oct4, Klf4 and c-Myc, when exogenously introduced into somatic cells, can lead to the formation of induced pluripotent stem (iPS) cells that have the capacity for self-renewal and differentiation into tissues of all three germ layers. In this review, we focus on the role of Krüppel-like factors (KLFs) in regulating somatic cell reprogramming. KLFs are zinc finger-containing transcription factors with diverse biological functions. We first provide an overview of the KLF family of regulatory proteins, paying special attention to the established biological and biochemical functions of KLF4 and KLF5. We then review the role of KLFs in somatic cell reprogramming and delineate the putative mechanism by which KLFs participates the establishment and self-renewal of iPS cells. Further research is likely to provide additional insight into the mechanisms of somatic cell reprogramming and refinement of the technique with which to generate clinically relevant iPS cells. PMID:19688699

Nandan, Mandayam O.; Yang, Vincent W.

2009-01-01

266

HMGA1 Reprograms Somatic Cells into Pluripotent Stem Cells by Inducing Stem Cell Transcriptional Networks  

PubMed Central

Background Although recent studies have identified genes expressed in human embryonic stem cells (hESCs) that induce pluripotency, the molecular underpinnings of normal stem cell function remain poorly understood. The high mobility group A1 (HMGA1) gene is highly expressed in hESCs and poorly differentiated, stem-like cancers; however, its role in these settings has been unclear. Methods/Principal Findings We show that HMGA1 is highly expressed in fully reprogrammed iPSCs and hESCs, with intermediate levels in ECCs and low levels in fibroblasts. When hESCs are induced to differentiate, HMGA1 decreases and parallels that of other pluripotency factors. Conversely, forced expression of HMGA1 blocks differentiation of hESCs. We also discovered that HMGA1 enhances cellular reprogramming of somatic cells to iPSCs together with the Yamanaka factors (OCT4, SOX2, KLF4, cMYC – OSKM). HMGA1 increases the number and size of iPSC colonies compared to OSKM controls. Surprisingly, there was normal differentiation in vitro and benign teratoma formation in vivo of the HMGA1-derived iPSCs. During the reprogramming process, HMGA1 induces the expression of pluripotency genes, including SOX2, LIN28, and cMYC, while knockdown of HMGA1 in hESCs results in the repression of these genes. Chromatin immunoprecipitation shows that HMGA1 binds to the promoters of these pluripotency genes in vivo. In addition, interfering with HMGA1 function using a short hairpin RNA or a dominant-negative construct blocks cellular reprogramming to a pluripotent state. Conclusions Our findings demonstrate for the first time that HMGA1 enhances cellular reprogramming from a somatic cell to a fully pluripotent stem cell. These findings identify a novel role for HMGA1 as a key regulator of the stem cell state by inducing transcriptional networks that drive pluripotency. Although further studies are needed, these HMGA1 pathways could be exploited in regenerative medicine or as novel therapeutic targets for poorly differentiated, stem-like cancers. PMID:23166588

Shah, Sandeep N.; Kerr, Candace; Cope, Leslie; Zambidis, Elias; Liu, Cyndi; Hillion, Joelle; Belton, Amy; Huso, David L.; Resar, Linda M. S.

2012-01-01

267

Exclusion of germ plasm proteins from somatic lineages by  

E-print Network

from somatic lineages by cullin-dependent degradation Cynthia DeRenzo1 *, Kimberly J. Reese1, or `germ plasm', to a small number of germline precursor cells during early embryogenesis1 . Germ plasm-germline (somatic) cells. We show that five CCCH finger proteins, components of the Cae- norhabditis elegans germ

Seydoux, Geraldine

268

Concise Review: Generation of Neurons From Somatic Cells of Healthy Individuals and Neurological Patients Through Induced Pluripotency or Direct Conversion  

PubMed Central

Access to healthy or diseased human neural tissue is a daunting task and represents a barrier for advancing our understanding about the cellular, genetic, and molecular mechanisms underlying neurogenesis and neurodegeneration. Reprogramming of somatic cells to pluripotency by transient expression of transcription factors was achieved a few years ago. Induced pluripotent stem cells (iPSC) from both healthy individuals and patients suffering from debilitating, life-threatening neurological diseases have been differentiated into several specific neuronal subtypes. An alternative emerging approach is the direct conversion of somatic cells (i.e., fibroblasts, blood cells, or glial cells) into neuron-like cells. However, to what extent neuronal direct conversion of diseased somatic cells can be achieved remains an open question. Optimization of current expansion and differentiation approaches is highly demanded to increase the differentiation efficiency of specific phenotypes of functional neurons from iPSCs or through somatic cell direct conversion. The realization of the full potential of iPSCs relies on the ability to precisely modify specific genome sequences. Genome editing technologies including zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeat/CAS9 RNA-guided nucleases have progressed very fast over the last years. The combination of genome-editing strategies and patient-specific iPSC biology will offer a unique platform for in vitro generation of diseased and corrected neural derivatives for personalized therapies, disease modeling and drug screening. Stem Cells 2014;32:2811–2817 PMID:24989459

Velasco, Iván; Salazar, Patricia; Giorgetti, Alessandra; Ramos-Mejía, Verónica; Castańo, Julio; Romero-Moya, Damiŕ; Menendez, Pablo

2014-01-01

269

Hormone-Induced Indirect Regeneration Protocol for Scutellaria baicalensis Georgi (Huang-qin)  

Microsoft Academic Search

There is no report available to date on somatic embryogenesis or even callus formation and plant regeneration in Scutellaria baiclensis (Huang qin). Ours is the first report on somatic embryo development in Scutellaria baicalensis. Plant growth regulators Thidiazuron [TDZ: N-phenyl N'- (1,2,3-thidiazol-5-ylurea)], 6-benzyladenine (BA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were tested alone or in combination for their capacity to induce indirect

Mala Trivedi; Rajesh Kumar Tiwari; Zhang Chun Guang; Guang-Qin Guo; Guo-Chang Zheng

2011-01-01

270

Original article Soybean mosaic virus helper component-protease enhances somatic  

E-print Network

; Somatic embryogenesis 1. Introduction Significant advances have been made in Agrobacterium- mediatedOriginal article Soybean mosaic virus helper component-protease enhances somatic embryo production of soybean hygromycin-resistant somatic embryos (HR-SEs), and stabilize transgene expression. Immature

Korban, Schuyler S.

271

Optimization of the uidA gene transfer into somatic embryos of rose via Agrobacterium tumefaciens  

E-print Network

; Somatic embryogenesis; Transformation; uidA gene 1. Introduction Roses are among the leading floriculturalOptimization of the uidA gene transfer into somatic embryos of rose via Agrobacterium tumefaciens somatic embryos via Agrobacterium-mediated transformation, but no transgenic plants were recovered

Korban, Schuyler S.

272

Repeated variate stress in male rats induces increased voiding frequency, somatic sensitivity, and urinary bladder nerve growth factor expression  

PubMed Central

Stress exacerbates symptoms of functional lower urinary tract disorders including interstitial cystitis (IC)/bladder pain syndrome (BPS) and overactive bladder (OAB) in humans, but mechanisms contributing to symptom worsening are unknown. These studies address stress-induced changes in the structure and function of the micturition reflex using an animal model of stress in male rats. Rats were exposed to 7 days of repeated variate stress (RVS). Target organ (urinary bladder, thymus, adrenal gland) tissues were collected and weighed following RVS. Evans blue (EB) concentration and histamine, myeloperoxidase (MPO), nerve growth factor (NGF), brain-derived neurotropic factor (BDNF), and CXCL12 protein content (ELISA) were measured in the urinary bladder, and somatic sensitivity of the hindpaw and pelvic regions was determined following RVS. Bladder function was evaluated using continuous, open outlet intravesical infusion of saline in conscious rats. Increases in body weight gain were significantly (P ? 0.01) attenuated by day 5 of RVS, and adrenal weight was significantly (P ? 0.05) increased. Histamine, MPO, NGF, and CXCL12 protein expression was significantly (P ? 0.01) increased in the urinary bladder after RVS. Somatic sensitivity of the hindpaw and pelvic regions was significantly (P ? 0.01) increased at all monofilament forces tested (0.1–4 g) after RVS. Intercontraction interval, infused volume, and void volume were significantly (P ? 0.01) decreased after RVS. These studies demonstrate increased voiding frequency, histamine, MPO, NGF, and CXCL12 bladder content and somatic sensitivity after RVS suggesting an inflammatory component to stress-induced changes in bladder function and somatic sensitivity. PMID:23657640

Merrill, Liana; Malley, Susan

2013-01-01

273

Inducing pluripotency in somatic cells from the snow leopard (Panthera uncia), an endangered felid.  

PubMed

Induced pluripotency is a new approach to produce embryonic stem-like cells from somatic cells that provides a unique means to understand both pluripotency and lineage assignment. To investigate whether this technology could be applied to endangered species, where the limited availability of gametes makes production and research on embryonic stem cells difficult, we attempted generation of induced pluripotent stem (iPS) cells from snow leopard (Panthera uncia) fibroblasts by retroviral transfection with Moloney-based retroviral vectors (pMXs) encoding four factors (OCT4, SOX2, KLF4 and cMYC). This resulted in the formation of small colonies of cells, which could not be maintained beyond four passages (P4). However, addition of NANOG, to the transfection cocktail produced stable iPS cell colonies, which formed as early as D3. Colonies of cells were selected at D5 and expanded in vitro. The resulting cell line was positive for alkaline phosphatase (AP), OCT4, NANOG, and Stage-Specific embryonic Antigen-4 (SSEA-4) at P14. RT-PCR also confirmed that endogenous OCT4 and NANOG were expressed by snow leopard iPS cells from P4. All five human transgenes were transcribed at P4, but OCT4, SOX2 and NANOG transgenes were silenced as early as P14; therefore, reprogramming of the endogenous pluripotent genes had occurred. When injected into immune-deficient mice, snow leopard iPS cells formed teratomas containing tissues representative of the three germ layers. In conclusion, this was apparently the first derivation of iPS cells from the endangered snow leopard and the first report on induced pluripotency in felid species. Addition of NANOG to the reprogramming cocktail was essential for derivation of iPS lines in this felid. The iPS cells provided a unique source of pluripotent cells with utility in conservation through cryopreservation of genetics, as a source of reprogrammed donor cells for nuclear transfer or for directed differentiation to gametes in the future. PMID:22079579

Verma, R; Holland, M K; Temple-Smith, P; Verma, P J

2012-01-01

274

Comparative proteomic analysis of somatic embryo maturation in Carica papaya L.  

PubMed Central

Background Somatic embryogenesis is a complex process regulated by numerous factors. The identification of proteins that are differentially expressed during plant development could result in the development of molecular markers of plant metabolism and provide information contributing to the monitoring and understanding of different biological responses. In addition, the identification of molecular markers could lead to the optimization of protocols allowing the use of biotechnology for papaya propagation and reproduction. This work aimed to investigate the effects of polyethylene glycol (PEG) on somatic embryo development and the protein expression profile during somatic embryo maturation in papaya (Carica papaya L.). Results The maturation treatment supplemented with 6% PEG (PEG6) resulted in the greatest number of somatic embryos and induced differential protein expression compared with cultures grown under the control treatment. Among 135 spots selected for MS/MS analysis, 76 spots were successfully identified, 38 of which were common to both treatments, while 14 spots were unique to the control treatment, and 24 spots were unique to the PEG6 treatment. The identified proteins were assigned to seven categories or were unclassified. The most representative class of proteins observed in the control treatment was associated with the stress response (25.8%), while those under PEG6 treatment were carbohydrate and energy metabolism (18.4%) and the stress response (18.4%). Conclusions The differential expression of three proteins (enolase, esterase and ADH3) induced by PEG6 treatment could play an important role in maturation, and these proteins could be characterized as candidate biomarkers of somatic embryogenesis in papaya. PMID:25076862

2014-01-01

275

A late embryogenesis abundant protein HVA1 regulated by an inducible promoter enhances root growth and abiotic stress tolerance in rice without yield penalty.  

PubMed

Regulation of root architecture is essential for maintaining plant growth under adverse environment. A synthetic abscisic acid (ABA)/stress-inducible promoter was designed to control the expression of a late embryogenesis abundant protein (HVA1) in transgenic rice. The background of HVA1 is low but highly inducible by ABA, salt, dehydration and cold. HVA1 was highly accumulated in root apical meristem (RAM) and lateral root primordia (LRP) after ABA/stress treatments, leading to enhanced root system expansion. Water-use efficiency (WUE) and biomass also increased in transgenic rice, likely due to the maintenance of normal cell functions and metabolic activities conferred by HVA1 which is capable of stabilizing proteins, under osmotic stress. HVA1 promotes lateral root (LR) initiation, elongation and emergence and primary root (PR) elongation via an auxin-dependent process, particularly by intensifying asymmetrical accumulation of auxin in LRP founder cells and RAM, even under ABA/stress-suppressive conditions. We demonstrate a successful application of an inducible promoter in regulating the spatial and temporal expression of HVA1 for improving root architecture and multiple stress tolerance without yield penalty. PMID:25200982

Chen, Yi-Shih; Lo, Shuen-Fang; Sun, Peng-Kai; Lu, Chung-An; Ho, Tuan-Hua D; Yu, Su-May

2015-01-01

276

Activation-induced cytidine deaminase: a dual role in class-switch recombination and somatic hypermutation  

Microsoft Academic Search

Maturation of the antibody repertoire is mediated by two different mechanisms: class-switch recombination (CSR) and somatic hypermutation (SHM). These two processes are T cell dependent and occur in the germinal centers of secondary lymphoid organs. CSR leads to the production of antibodies of different isotypes whereas SHM leads to the selection of B cells expressing a BCR with high affinity

Anne Durandy

277

Embryogenesis: anchors away!  

PubMed

It has long been appreciated that the oocyte cortex plays a key role in regulating fertilization and establishing embryonic polarity. Recent studies have identified the anti-phosphatase EGG-3 as a cortical anchor for regulatory proteins required for launching embryogenesis in Caenhorhabditis elegans. PMID:17956750

Govindan, J Amaranath; Greenstein, David

2007-10-23

278

Decrease in topoisomerase I is responsible for activation-induced cytidine deaminase (AID)-dependent somatic hypermutation  

PubMed Central

Somatic hypermutation (SHM) and class-switch recombination (CSR) of the Ig gene require both the transcription of the locus and the expression of activation-induced cytidine deaminase (AID). During CSR, AID decreases the amount of topoisomerase I (Top1); this decrease alters the DNA structure and induces cleavage in the S region. Similarly, Top1 is involved in transcription-associated mutation at dinucleotide repeats in yeast and in triplet-repeat contraction in mammals. Here, we report that the AID-induced decrease in Top1 is critical for SHM. Top1 knockdown or haploinsufficiency enhanced SHM, whereas Top1 overexpression down-regulated it. A specific Top1 inhibitor, camptothecin, suppressed SHM, indicating that Top1's activity is required for DNA cleavage. Nonetheless, suppression of transcription abolished SHM, even in cells with Top1 knockdown, suggesting that transcription is critical. These results are consistent with a model proposed for CSR and triplet instability, in which transcription-induced non-B structure formation is enhanced by Top1 reduction and provides the target for irreversible cleavage by Top1. We speculate that the mechanism for transcription-coupled genome instability was adopted to generate immune diversity when AID evolved. PMID:22080610

Kobayashi, Maki; Sabouri, Zahra; Sabouri, Somayeh; Kitawaki, Yoko; Pommier, Yves; Abe, Takaya; Kiyonari, Hiroshi; Honjo, Tasuku

2011-01-01

279

The germline of multicellular animals is segregated from somatic tissues, which is an essential developmental process for  

E-print Network

4113 Summary The germline of multicellular animals is segregated from somatic tissues, which segregate their germline during embryogenesis, animals from other taxa segregate their germline after embryogenesis from multipotent progenitor cells. An overlapping set of genes, including vasa, nanos and piwi

Wessel, Gary M.

280

Modulatory effects of Tabebuia impetiginosa (Lamiales, Bignoniaceae) on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster.  

PubMed

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and ?-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10%, 20% or 40% w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0%) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture. PMID:21637695

de Sousa, Neila C; de Rezende, Alexandre A A; da Silva, Regildo M G; Guterres, Zaira R; Graf, Ulrich; Kerr, Warwick E; Spanó, Mário A

2009-04-01

281

Modulatory effects of Tabebuia impetiginosa (Lamiales, Bignoniaceae) on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster  

PubMed Central

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and ?-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10%, 20% or 40% w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0%) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture. PMID:21637695

2009-01-01

282

Siberian Sturgeon Oocyte Extract Induces Epigenetic Modifications of Porcine Somatic Cells and Improves Developmental Competence of SCNT Embryos  

PubMed Central

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with 4 ?g/mL of digitonin for 2 min at 4°C in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at 18°C was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos. PMID:25049951

Kim, So-Young; Kim, Tae-Suk; Park, Sang-Hoon; Lee, Mi-Ran; Eun, Hye-Ju; Baek, Sang-Ki; Ko, Yeoung-Gyu; Kim, Sung-Woo; Seong, Hwan-Hoo; Campbell, Keith H.S.; Lee, Joon-Hee

2014-01-01

283

Somatic mosaicism and allele complexity induced by CRISPR/Cas9 RNA injections in mouse zygotes  

PubMed Central

Tyrosinase is the rate-limiting enzyme for the production of melanin pigmentation. In the mouse and other animals, homozygous null mutations in the Tyrosinase gene (Tyr) result in the absence of pigmentation, i.e. albinism. Here we used the CRISPR/Cas9 system to generate mono- and bi-allelic null mutations in the Tyr locus by zygote injection of two single-guide and Cas9 RNAs. Injection into C57BL/6N wild-type embryos resulted in one completely albino founder carrying two different Tyr mutations. In addition, three pigmentation mosaics and fully pigmented littermates were obtained that transmitted new mutant Tyr alleles to progeny in test crosses with albinos. Injection into Tyr heterozygous (B6CBAF1/J × FVB/NJ) zygotes resulted in the generation of numerous albinos and also mice with a graded range of albino mosaicism. Deep sequencing revealed that the majority of the albinos and the mosaics had more than two new mutant alleles. These visual phenotypes and molecular genotypes highlight the somatic mosaicism and allele complexity in founders that occurs for targeted genes during CRISPR/Cas9-mediated mutagenesis by zygote injection in mice. PMID:24984260

Yen, Shuo-Ting; Zhang, Min; Deng, Jian Min; Usman, Shireen J.; Smith, Chad N.; Parker-Thornburg, Jan; Swinton, Paul G.; Martin, James F.; Behringer, Richard R.

2014-01-01

284

Somatic mosaicism and allele complexity induced by CRISPR/Cas9 RNA injections in mouse zygotes.  

PubMed

Tyrosinase is the rate-limiting enzyme for the production of melanin pigmentation. In the mouse and other animals, homozygous null mutations in the Tyrosinase gene (Tyr) result in the absence of pigmentation, i.e. albinism. Here we used the CRISPR/Cas9 system to generate mono- and bi-allelic null mutations in the Tyr locus by zygote injection of two single-guide and Cas9 RNAs. Injection into C57BL/6N wild-type embryos resulted in one completely albino founder carrying two different Tyr mutations. In addition, three pigmentation mosaics and fully pigmented littermates were obtained that transmitted new mutant Tyr alleles to progeny in test crosses with albinos. Injection into Tyr heterozygous (B6CBAF1/J×FVB/NJ) zygotes resulted in the generation of numerous albinos and also mice with a graded range of albino mosaicism. Deep sequencing revealed that the majority of the albinos and the mosaics had more than two new mutant alleles. These visual phenotypes and molecular genotypes highlight the somatic mosaicism and allele complexity in founders that occurs for targeted genes during CRISPR/Cas9-mediated mutagenesis by zygote injection in mice. PMID:24984260

Yen, Shuo-Ting; Zhang, Min; Deng, Jian Min; Usman, Shireen J; Smith, Chad N; Parker-Thornburg, Jan; Swinton, Paul G; Martin, James F; Behringer, Richard R

2014-09-01

285

Isolation of the phagocytosis-inducing IgG-binding antigen on senescent somatic cells  

NASA Astrophysics Data System (ADS)

To remove senescent red blood cells (RBCs) from the circulation, macrophages must distinguish them from mature RBCs. That is achieved by a specific recognition system1,2. An antigen that develops on the surface of a senescing RBC is recognized and bound by the Fab region1 of an IgG autoantibody in the serum2. Subsequently the Fc region of the autoantibody is recognized and bound by a macrophage3, which proceeds to phagocytose the RBC. The antigenic molecule can be extracted from senescent but not young RBCs with Triton X-100 (ref. 4), although 10-30% as much antigen can be extracted from middle-aged as from senescent RBCs4. I have now used IgG autoantibodies eluted from senescent RBCs to isolate and purify the IgG-binding antigen on senescent RBCs, andto detect the antigen on other somatic cells. The antigen is a ~=62,000-Mr protein which is present on stored platelets, lymphocytes and neutrophils, and on cultured human adult liver and embryonic kidney cells, as well as senescent RBCs.

Kay, Marguerite M. B.

1981-02-01

286

Paternal effects on early embryogenesis  

PubMed Central

Historically, less attention has been paid to paternal effects on early embryogenesis than maternal effects. However, it is now apparent that certain male factor infertility phenotypes are associated with increased DNA fragmentation and/or chromosome aneuploidies that may compromise early embryonic development. In addition, there is a growing body of evidence that the fertilizing sperm has more function than just carrying an intact, haploid genome. The paternally inherited centrosome is essential for normal fertilization, and the success of higher order chromatin packaging may impact embryogenesis. Epigenetic modifications of sperm chromatin may contribute to the reprogramming of the genome, and sperm delivered mRNA has also been hythesized to be necessary for embryogenesis. There is less information about the epigenetic factors affecting embryogenesis than genetic factors, but the epigenetics of gamete and early embryogenesis is a rapidly advancing field. PMID:18485208

Nanassy, Laszlo; Carrell, Douglas T

2008-01-01

287

NMDA receptor mediates chronic visceral pain induced by neonatal noxious somatic stimulation.  

PubMed

NMDA receptors (NMDAR) are important in the development and maintenance of central sensitization. Our objective was to investigate the role of spinal neurons and NMDAR in the maintenance of chronic visceral pain. Neonatal rats were injected with acidic saline adjusted to pH 4.0 in the gastrocnemius muscle every other day for 12 days. In adult rats, NR1 and NR2B subunits were examined in the lumbo-sacral (LS) spinal cord. A baseline, visceromotor response (VMR) to graded colorectal distension (CRD) was recorded before and after administration of the NMDA antagonist, CGS-19755. Extracellular recordings were performed from CRD-sensitive LS spinal neurons and pelvic nerve afferents (PNA) before and after CGS-19755. Rats that received pH 4.0 saline injections demonstrated a significant increase in the expression NR2B subunits and VMR response to CRD>20mmHg. CGS-19755 (i.v. or i.t.) had no effect in naďve rats, but significantly decreased the response to CRD in pH 4.0 saline injected rats. CGS-19755 had no effect on the spontaneous firing of SL-A, but decreased that of SL-S. Similarly, CGS-19755 attenuates the responses of SL-S neurons to CRD, but had no effect on SL-A neurons or on the response characteristics of PNA fibers. Neonatal noxious somatic stimulation results in chronic visceral hyperalgesia and sensitizes a specific subpopulation of CRD-sensitive spinal neurons. The sensitization of these SL-S spinal neurons is attenuated by the NMDAR antagonist. The results of this study suggest that spinal NMDARs play an important role in the development of hyperalgesia early in life. PMID:25281204

Miranda, Adrian; Mickle, Aaron; Bruckert, Mitchell; Kannampalli, Pradeep; Banerjee, Banani; Sengupta, Jyoti N

2014-12-01

288

PIWI proteins are essential for early Drosophila embryogenesis  

PubMed Central

PIWI proteins, a subfamily of the ARGONAUTE/PIWI protein family, have been implicated in transcriptional and posttranscriptional gene regulation and transposon silencing mediated by small non-coding RNAs, especially piRNAs. Although these proteins are known to be required for germline development, their somatic function remains elusive. Here, we examine the maternal function of all three PIWI proteins in Drosophila; Piwi, Aubergine (Aub) and Argonaute3 (Ago3) during early embryogenesis. In syncytial embryos, Piwi displays an embryonic stage-dependent localization pattern. Piwi is localized in the cytoplasm during mitotic cycles 1-10. Between cycles 11 and 14, Piwi remains in the cytoplasm during mitosis but moves into the somatic nucleus during interphase. Beyond cycle 14, it stays in the nucleus. Aub and Ago3 are diffusely cytoplasmic from cycle 1-14. Embryos maternally depleted of any one of the three PIWI proteins display severe mitotic defects, including abnormal chromosome and nuclear morphology, cell cycle arrest, asynchronous nuclear division and aberrant nuclear migration. Furthermore, all three PIWI proteins are required for the assembly of mitotic machinery and progression through mitosis. Embryos depleted of maternal PIWI proteins also exhibit chromatin organization abnormalities. These observations indicate that maternal Piwi, Aub and Ago3 play a critical role in the maintenance of chromatin structure and cell cycle progression during early embryogenesis, with compromised chromatin integrity as a possible cause of the observed mitotic defects. Our study demonstrates the essential function of PIWI proteins in the first phase of somatic development. PMID:24184635

Mani, Sneha Ramesh; Megosh, Heather; Lin, Haifan

2014-01-01

289

Somatic Embryogenesis in Eastern White Pine ( Pinus Strobus L.)  

Microsoft Academic Search

\\u000a \\u000a Pinus strobus L. (eastern white pine or weymouth pine) is an important timber species of North America. It is one of the about one hundred\\u000a species of the genus Pinus of the family Pinaceae of the order Coniferae (Mirov, 1967). Like all other species of Pinus, the haploid genome of Pinus strobus consists of 12 chromosomes and its diploid genome

Karan Kaul

290

Alfalfa heat shock genes are differentially expressed during somatic embryogenesis  

Microsoft Academic Search

We have isolated two cDNA clones (Mshsp18-1; Mshsp18-2) from alfalfa (Medicago sativa L.) which encode for small heat shock proteins (HSPs) belonging to the hsp17 subfamily. The predicted amino acid sequences of the two alfalfa proteins are 92% identical and a similar degree of homology (90%) can be detected between Mshsp 18-2 and the pea hsp 17. In comparison to

János Györgyey; Anton Gartner; Kinga Németh; Zoltán Magyar; Heribert Hirt; Erwin Heberle-Bors; Dénes Dudits

1991-01-01

291

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

Microsoft Academic Search

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

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

1988-01-01

292

Somatic Embryogenesis From Mature Seed Cultures of Pistacia atlantica  

Microsoft Academic Search

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

Ahmet ONAY

2000-01-01

293

Somatic rearrangements across cancer reveal classes of samples with distinct patterns of DNA breakage and rearrangement-induced hypermutability  

E-print Network

Whole-genome sequencing using massively parallel sequencing technologies enables accurate detection of somatic rearrangements in cancer. Pinpointing large numbers of rearrangement breakpoints to base-pair resolution allows ...

Lander, Eric S.

294

Fishery-induced selection for slow somatic growth in European eel.  

PubMed

Both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. We compared body growth rates in European eel (Anguilla anguilla) from three Mediterranean stocks subject to different fishing pressure. Results are consistent with the hypotheses that i) fast-growing individuals are more likely to survive until sexual maturity than slow-growing ones under natural conditions (no fishing) and ii) fishing can select for slow-growing individuals by removing fast-growing ones. Although the possibility of human-induced evolution seems remote for a panmictic species like such as the European eel, further research is desirable to assess the implications of the intensive exploitation on this critically endangered fish. PMID:22666373

Bevacqua, Daniele; Capoccioni, Fabrizio; Meliŕ, Paco; Vincenzi, Simone; Pujolar, José M; De Leo, Giulio A; Ciccotti, Eleonora

2012-01-01

295

Morphogenic competence of Vitis rupestris S. secondary somatic embryos with a long culture history  

Microsoft Academic Search

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

2001-01-01

296

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

PubMed

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

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

2014-02-01

297

Myogenin induces higher oxidative capacity in pre-existing mouse muscle fibres after somatic DNA transfer  

PubMed Central

Muscle is a permanent tissue, and in the adult pronounced changes can occur in pre-existing fibres without the formation of new fibres. Thus, the mechanisms responsible for phenotype transformation in the adult might be distinct from mechanisms regulating muscle differentiation during muscle formation and growth. Myogenin is a muscle-specific, basic helix-loop-helix transcription factor that is important during early muscle differentiation. It is also expressed in the adult, where its role is unknown. In this study we have overexpressed myogenin in glycolytic fibres of normal adult mice by electroporation and single-cell intracellular injection of expression vectors. Myogenin had no effects on myosin heavy chain fibre type, but induced a considerable increase in succinate dehydrogenase and NADH dehydrogenase activity, with some type IIb fibres reaching the levels observed histochemically in normal type IIx and IIa fibres. mRNA levels for malate dehydrogenase were similarly altered. The size of the fibres overexpressing myogenin was reduced by 30–50 %. Thus, the transfected fibres acquired a phenotype reminiscent of the phenotype obtained by endurance training in man and other animals, with a higher oxidative capacity and smaller size. We conclude that myogenin can alter pre-existing glycolytic fibres in the intact adult animal. PMID:12598590

Ekmark, Merete; Grřnevik, Eirik; Schjerling, Peter; Gundersen, Kristian

2003-01-01

298

A threshold exists in the dose-response relationship for somatic mutation frequency induced by X irradiation of Drosophila.  

PubMed

The dose-response relationship of ionizing radiation and its stochastic effects has been thought to be linear without any thresholds. The basic data for this model were obtained from mutational assays in the male germ cells of the fruit fly Drosophila melanogaster. However, it is more appropriate to examine carcinogenic activity in somatic cells than in germ cells. Here the dose-response relationship of X irradiation and somatic mutation was examined in Drosophila. A threshold at approximately 1 Gy was observed in DNA repair-proficient flies. In the repair-deficient siblings, the threshold was smaller and the inclination of the dose-response curve was much steeper. These results suggest that the dose-response relationship between X irradiation and somatic mutation has a threshold and that the DNA repair function contributes to its formation. PMID:15038774

Koana, Takao; Takashima, Yoshio; Okada, Mikie O; Ikehata, Masateru; Miyakoshi, Junji; Sakai, Kazuo

2004-04-01

299

Proteomic Analysis of Early Reprogramming Events in Murine Somatic Cells Incubated with Xenopus laevis Oocyte Extracts Demonstrates Network Associations with Induced Pluripotency Markers  

PubMed Central

Abstract The reprogramming of somatic cells into a pluripotent/embryonic-like state holds great potential for regenerative medicine, bypassing ethical issues associated with embryonic stem cells (ESCs). Numerous methods, including somatic cell nuclear transfer (SCNT), fusion to pluripotent cells, the use of cell extracts, and expression of transcription factors, have been used to reprogram cells into ES-like cells [termed induced pluripotent stem cells (iPSCs)]. This study investigated early events in the nuclei of permeabilized murine somatic cells incubated in cytoplasmic extract prepared from Xenopus laevis germinal vesicle–stage oocytes by identifying proteins that showed significant quantitative changes using proteomic techniques. A total of 69 protein spots from two-dimensional electrophoresis were identified as being significantly altered in expression after treatment, and 38 proteins were identified by tandem mass spectrometry. Network analysis was used to highlight pathway connections and interactions between these identified proteins, which were found to be involved in many functions—primarily nuclear structure and dynamics, transcription, and translation. The pluripotency markers Klf4, c-Myc, Nanog, and POU5F1 were highlighted by the interaction network analysis, as well as other compounds/proteins known to be repressed in pluripotent cells [e.g., protein kinase C (PRKC)] or enhanced during differentiation of ESCs (e.g., retinoic acid). The network analysis also indicated additional proteins and pathways potentially involved in early reprogramming events. PMID:23768116

Liddell, Susan; Campbell, Keith H.S.

2013-01-01

300

Inhibitory effects of water extract of propolis on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster  

Microsoft Academic Search

Propolis is a substance produced by honeybees (Apis mellifera L.). Its components are strong antioxidants and free radical scavengers. The aim of this study was to evaluate the protective effects of a water extract of Brazilian green propolis (WEP) combined with the antitumor agent doxorubicin (DXR) on Drosophila melanogaster wing cells through the somatic mutation and recombination test (SMART). Two

B. L. B. Valadares; U. Graf; M. A. Spanó

2008-01-01

301

Analysis of Human and Mouse Reprogramming of Somatic Cells to Induced Pluripotent Stem Cells. What Is in the Plate?  

Microsoft Academic Search

After the hope and controversy brought by embryonic stem cells two decades ago for regenerative medicine, a new turn has been taken in pluripotent cells research when, in 2006, Yamanaka's group reported the reprogramming of fibroblasts to pluripotent cells with the transfection of only four transcription factors. Since then many researchers have managed to reprogram somatic cells from diverse origins

Stéphanie Boué; Ida Paramonov; María José Barrero; Juan Carlos Izpisúa Belmonte

2010-01-01

302

Control of ciliation in embryogenesis.  

PubMed

The protrusion of cilia into extracellular space provides cells with sensors of localized environmental cues that include fluid flow, mechanical force and important growth factors such as Hedgehog. Live imaging has now captured the initial appearance of cilia during embryogenesis, and defined lineage-specific determinants that restrict extra-embryonal ciliogenesis. PMID:25633272

Nikonova, Anna S; Golemis, Erica A

2015-01-30

303

Plant regeneration from somatic embryos of Taxus brevifolia  

Microsoft Academic Search

Summary Taxusbrevifolia is the source of paclitaxel (Taxol®), an anticancer drug. A method for regeneration ofTaxus brevifolia from immature zygotic embryos via somatic embryogenesis is described. Embryogenic callus tissues were obtained by culturing immature zygotic embryos on Lloyd and McCown medium (MCM) supplemented with 160 ?M 2,4-dichlorophenoxyacetic acid (2,4-D) + 5 ?M benzylaminopurine (BA) + 5 ?M naphthaleneacetic acid (NAA)

Paula P. Chee

1996-01-01

304

Somatic rearrangements across cancer reveal classes of samples with distinct patterns of DNA breakage and rearrangement-induced hypermutability  

PubMed Central

Whole-genome sequencing using massively parallel sequencing technologies enables accurate detection of somatic rearrangements in cancer. Pinpointing large numbers of rearrangement breakpoints to base-pair resolution allows analysis of rearrangement microhomology and genomic location for every sample. Here we analyze 95 tumor genome sequences from breast, head and neck, colorectal, and prostate carcinomas, and from melanoma, multiple myeloma, and chronic lymphocytic leukemia. We discover three genomic factors that are significantly correlated with the distribution of rearrangements: replication time, transcription rate, and GC content. The correlation is complex, and different patterns are observed between tumor types, within tumor types, and even between different types of rearrangements. Mutations in the APC gene correlate with and, hence, potentially contribute to DNA breakage in late-replicating, low %GC, untranscribed regions of the genome. We show that somatic rearrangements display less microhomology than germline rearrangements, and that breakpoint loci are correlated with local hypermutability with a particular enrichment for transversions. PMID:23124520

Drier, Yotam; Lawrence, Michael S.; Carter, Scott L.; Stewart, Chip; Gabriel, Stacey B.; Lander, Eric S.; Meyerson, Matthew; Beroukhim, Rameen; Getz, Gad

2013-01-01

305

Reprogramming of somatic cells induced by fusion of embryonic stem cells using hemagglutinating virus of Japan envelope (HVJ-E)  

SciTech Connect

In this research, hemagglutinating virus of Japan envelope (HVJ-E) was used to reprogram somatic cells by fusion with mouse embryonic stem (ES) cells. Neomycin-resistant mouse embryonic fibroblasts (MEFs) were used as somatic cells. Nanog-overexpressing puromycin-resistant EB3 cells were used as mouse ES cells. These two cells were fused by exposing to HVJ-E and the generated fusion cells were selected by puromycin and G418 to get the stable fusion cell line. The fusion cells form colonies in feeder-free culture system. Microsatellite analysis of the fusion cells showed that they possessed genes from both ES cells and fibroblasts. The fusion cells were tetraploid, had alkali phosphatase activity, and expressed stem cell marker genes such as Pou5f1, Nanog, and Sox2, but not the fibroblast cell marker genes such as Col1a1 and Col1a2. The pluripotency of fusion cells was confirmed by their expression of marker genes for all the three germ layers after differentiation induction, and by their ability to form teratoma which contained all the three primary layers. Our results show that HVJ-E can be used as a fusion reagent for reprogramming of somatic cells.

Yue, Xiao-shan [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan) [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Fujishiro, Masako [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)] [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Toyoda, Masashi [Department of Reproductive Biology, National Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535 (Japan)] [Department of Reproductive Biology, National Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan)] [Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Ito, Yoshihiro, E-mail: y-ito@riken.jp [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan) [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan)

2010-04-16

306

Somatic Cell-Induced Hyperacetylation, But Not Hypomethylation, Positively and Reversibly Affects the Efficiency of In Vitro Cloned Blastocyst Production in Cattle  

PubMed Central

Abstract 5-Aza-2?-deoxycytidine (AzC), trichostatin A (TSA), and its natural mimetic, sodium butyrate (NaB), are antineoplastic drugs that can modify the epigenetic status of donor cells prior to somatic cell nuclear transfer (SCNT). In this study, we used fibroblast cells treated with these drugs to investigate the direct and indirect effects of induced changes in DNA methylation and acetylation of the lysine 9 residue of histone H3 (H3K9). Additionally, we assayed cellular characteristics (cell growth, cell proliferation, cell cycle progression, and apoptosis) and SCNT efficiency in response to these drugs as well as monitoring these effects 24?h after removing the drugs. We observed the following: (1) AzC, TSA, and NaB all showed dose-dependent effects on different cellular characteristics; (2) TSA and NaB induced H3K9 hyperacetylation accompanied by DNA hypermethylation, whereas AzC induced DNA hypomethylation with no effect on H3K9 hyperacetylation; (3) TSA and NaB improved cloning efficiency, whereas AzC reduced it; and (4) unlike AzC, the effects of TSA and NaB on cellular characteristics and SCNT efficiency were reversed following drug removal. Our results indicate that somatic cells treated with TSA and NaB show better survival and recovery rates following the removal of these drugs. Moreover, H3K9 hyperacetylation (induced with TSA and NaB), but not DNA hypomethylation (induced with AzC), favors cloning efficiency. PMID:21919704

Jafarpour, Farnoosh; Hosseini, Sayed Morteza; Hajian, Mehdi; Forouzanfar, Mohsen; Ostadhosseini, Somayyeh; Abedi, Parvaneh; Gholami, Soghra; Ghaedi, Kamran; Gourabi, Hamid; Shahverdi, Abdol Hossein; Vosough, Ahmad Dizaj Taghi

2011-01-01

307

A Critical Role of Mitochondrial Phosphatase Ptpmt1 in Embryogenesis Reveals a Mitochondrial Metabolic Stress-Induced Differentiation Checkpoint in Embryonic Stem Cells ?  

PubMed Central

Mitochondria are highly dynamic organelles that play multiple roles in cells. How mitochondria cooperatively modulate embryonic stem (ES) cell function during development is not fully understood. Global disruption of Ptpmt1, a mitochondrial Pten-like phosphatidylinositol phosphate (PIP) phosphatase, resulted in developmental arrest and postimplantation lethality. Ptpmt1?/? blastocysts failed to outgrow, and inner-cell-mass cells failed to thrive. Depletion of Ptpmt1 in conditional knockout ES cells decreased proliferation without affecting energy homeostasis or cell survival. Differentiation of Ptpmt1-depleted ES cells was essentially blocked. This was accompanied by upregulation of cyclin-dependent kinase inhibitors and a significant cell cycle delay. Reintroduction of wild-type but not of catalytically deficient Ptpmt1 C132S or truncated Ptpmt1 lacking the mitochondrial localization signal restored the differentiation capabilities of Ptpmt1 knockout ES cells. Intriguingly, Ptpmt1 is specifically important for stem cells, as ablation of Ptpmt1 in differentiated embryonic fibroblasts did not disturb cellular function. Further analyses demonstrated that oxygen consumption of Ptpmt1-depleted cells was decreased, while glycolysis was concomitantly enhanced. In addition, mitochondrial fusion/dynamics were compromised in Ptpmt1 knockout cells due to accumulation of PIPs. These studies, while establishing a crucial role for Ptpmt1 phosphatase in embryogenesis, reveal a mitochondrial metabolic stress-activated checkpoint in the control of ES cell differentiation. PMID:21986498

Shen, Jinhua; Liu, Xia; Yu, Wen-Mei; Liu, Jie; Groot Nibbelink, Milou; Guo, Caiying; Finkel, Toren; Qu, Cheng-Kui

2011-01-01

308

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

Microsoft Academic Search

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

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

1993-01-01

309

SYCHRONIZED SOMATIC EMBRYO DEVELOPMENT IN EMBRYOGENIC SUSPENSIONS OF GRAPEVINE (MUSCADINIA ROTUNDIFOLIA SMALL AND VITIS VINIFERA L.)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The full advantages of somatic embryogenesis 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...

310

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

E-print Network

,3 When plant tissues are damaged, the linamarin and its hydrolytic enzyme, linamarase, come into contact hydrolytic enzyme, linamarase. In this paper, a protocol for high frequency cyclic somatic embryogenesis or ligands of many enzymes.5 In humans, cyanide exposure could lead to a number of disorders such as goitre

Yeoh, Hock Hin

311

Effects of abscisic acid and high concentrations of PEG on Hevea brasiliensis somatic embryos development  

Microsoft Academic Search

The effects of polyethylene glycol (PEG) and abscisic acid (ABA) were analysed on Hevea brasiliensis somatic embryos development. The presence of osmoticum greatly reduced the phenomenon of secondary embryogenesis and improved the conversion of proembryonic masses (PEMs) into torpedo-shaped embryos, while the addition of exogenous ABA favoured only the formation of globular-stage embryos. The development of embryos with a desirable

Laurent Linossier; Philippe Veisseire; Françoise Cailloux; Alain Coudret

1997-01-01

312

Microspore embryogenesis in Apiaceae  

Microsoft Academic Search

Haploid technology is used to develop uniform, true-breeding lines, as well as to accelerate crop improvement programs. Among\\u000a 20 Apiaceae species screened for response to doubled haploidy, 11 generated microspore-derived embryos, and all but one of\\u000a the latter yielded doubled haploid plants. Donor plant conditions, basal media, and culture conditions were evaluated for\\u000a their efficacy on inducing microspore-derived embryos. Growing

A. M. R. Ferrie; T. D. Bethune; M. Mykytyshyn

2011-01-01

313

A new microspore embryogenesis system under low temperature which mimics zygotic embryogenesis initials, expresses auxin and efficiently regenerates doubled-haploid plants in Brassica napus  

PubMed Central

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 embryogenesis induction. 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 embryogenesis induction 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. PMID:22857779

2012-01-01

314

Embryogenesis of Xyleborus ferrugineus (Fabr.) (Coleoptera, Scolytidae). I. External morphogenesis of male and female embryos.  

PubMed

A description of the external morphogenesis of male and female embryos of X. ferrugineus, derived from in vivo observation, is presented here. The embryogenesis of this beetle is typical of the Coleoptera, and is also similar in most respects to the generalized insect plan. Observed unusual aspects of X. ferrugineus embryogenesis include the precocious formation of primordial g/rm cells and their temporary exclusion from somatic blastoderm; the precocious in situ delineation of gnathal metameres, the closing of the gastral groove beginning at both ends and proceeding towards its middle, the formation of several paired lateral amnio-serosal folds, the formation of cellular processes between the amnion and serosa, and the absorption of the thoracic limbs to produce an apodous larva. The embryonic developmental picture provided here, and the previously established means of rearing X. ferrugineus in controlled laboratory culture jointly provide a promising basis for the further use of this insect in developmental studies. PMID:864710

Beeman, S L; Norris, D M

1977-05-01

315

Epigenetic and hormonal profile during maturation of Quercus Suber L. somatic embryos.  

PubMed

Somatic embryogenesis is a powerful alternative to conventional mass propagation of Quercus suber L. However, poor quality and incomplete maturation of somatic embryos restrict any application. Given that epigenetic and hormonal control govern many developmental stages, including maturation of zygotic embryos, global DNA methylation and abscisic acid (ABA) were analyzed during development and maturation of cork oak somatic embryos. Our results indicated that development of somatic embryos concurred with a decrease in 5-mdC. In contrast, endogenous ABA content showed a transient increase with a peak in immature E2 embryos denoting the onset of the maturation phase. A cold stratification phase was necessary for embryos to acquire germination ability, which coincided with a significant decrease in 5-mdC and ABA content. Immunohistochemical analyses showed that there was a specific spatial-temporal regulation during embryogenesis, particularly after the cold treatment. The acquisition of germination capacity concurred with a general low 5-mdC signal in the root meristem, while retention of the 5-mdC signal was mainly located in the shoot meristem and provascular tissues. Conversely, ABA immunolocalization was mainly located in the root and shoot apical meristems. Furthermore, a strong decrease in the ABA signal was observed in the root cap after the stratification treatment suggesting a role for the root cap during development of somatic embryos. These results suggest that, in addition to ABA, epigenetic control appears to play an important role for the correct maturation and subsequent germination of cork oak somatic embryos. PMID:25462078

Pérez, Marta; Viejo, Marcos; LaCuesta, Maite; Toorop, Peter; Cańal, María Jesús

2014-09-17

316

Glucocorticoid receptors participate in the opiate withdrawal-induced stimulation of rats NTS noradrenergic activity and in the somatic signs of morphine withdrawal  

PubMed Central

BACKGROUND AND PURPOSE Recent evidence suggests that glucocorticoid receptor (GR) is a major molecular substrate of addictive properties of drugs of abuse. Hence, we performed a series of experiments to further characterize the role of GR signalling in opiate withdrawal-induced physical signs of dependence, enhanced noradrenaline (NA) turnover in the hypothalamic paraventricular nucleus (PVN) and tyrosine hydroxylase (TH) phosphorylation (activation) as well as GR expression in the nucleus of the solitary tract noradrenergic cell group (NTS-A2). EXPERIMENTAL APPROACH The role of GR signalling was assessed by i.p. pretreatment of the selective GR antagonist, mifepristone. Rats were implanted with two morphine (or placebo) pellets. Six days later, rats were pretreated with mifepristone or vehicle 30 min before naloxone and physical signs of abstinence, NA turnover, TH activation, GR expression and the hypothalamus–pituitary–adrenocortical axis activity were measured using HPLC, immunoblotting and RIA. KEY RESULTS Mifepristone alleviated the somatic signs of naloxone-induced opiate withdrawal. Mifepristone attenuated the increase in the NA metabolite, 3-methoxy-4-hydroxyphenylethylen glycol (MHPG), in the PVN, and the enhanced NA turnover observed in morphine-withdrawn rats. Mifepristone antagonized the TH phosphorylation at Ser31 and the expression of c-Fos expression induced by morphine withdrawal. Finally, naloxone-precipitated morphine withdrawal induced up-regulation of GR in the NTS. CONCLUSIONS AND IMPLICATIONS These results suggest that the physical signs of opiate withdrawal, TH activation and stimulation of noradrenergic pathways innervating the PVN are modulated by GR signalling. Overall, the present data suggest that drugs targeting the GR may ameliorate stress and aversive effects associated with opiate withdrawal. PMID:22364199

Navarro-Zaragoza, Javier; Hidalgo, Juana M; Laorden, M Luisa; Milanés, M Victoria

2012-01-01

317

High Efficiency Somatic Embrogenesis and Plant Regeneration in Suspension Cultures of an Ornamental Ginger Hybrid (Hedychium muluense x cv ‘Starburst’)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants were successfully regenerated via somatic embryogenesis from shoot apex-derived callus of an ornamental ginger hybrid, Hedychium muluense x cv ‘Starburst’. H. muluense is a dwarf species and ‘Starburst’ is a hybrid cultivar with white and very fragrant flowers in a circular, wheel-like arrang...

318

Protective effects of new medicinal mushroom, Grifola gargal singer (higher Basidiomycetes), on induced DNA damage in somatic cells of Drosophila melanogaster.  

PubMed

Grifola gargal is an edible mushroom with attributed antioxidant properties. Different sources of G. gargal materials, i.e., fruit bodies and mycelia grown in liquid or solid media, were used to study its potential protective capacity when somatic mutation and recombination is induced in Drosophila melanogaster using DMBA (7-12-dimethyl-benz(?)anthracene) as promutagen. Heterozygote larvae (white/white+) were grown in media with different concentrations of DMBA. Grifola gargal fruit bodies (GgFB) or mycelia from liquid culture (GgLC) or from solid culture (GgWG), i.e., biotransformed wheat kernel flour, were added to the culture media in combined treatments with DMBA. Water, DMBA solvent, or wheat flour (WF) plus DMBA solvent were used as negative controls. Larval mortality increased from 9% to 11% in negative controls to 31% to 36% in DMBA treatments. The addition of GgFB, GgLC, or GgWG materials produced a protective effect on 25 ?mol/vial DMBA-induced mortality. Mutations observed in SMART, as light spots per 100 eyes (LS/100 eyes), increased with increasing doses of DMBA; this was also true when considering the mutation incidence expressed as percentage of eyes exhibiting light spots (% eyes with LS). Interestingly, mycelia from GgFB, GgLC, or GgWG, in the presence of 25 ?mol/vial DMBA, showed lower values in SMART of both the total LS/100 eyes and the percentage of eyes with LS. Thus, Grifola gargal materials were not only nontoxic, but in combination with 25 ?mol/vial DMBA lowered the mortality induced by the promutagen and showed antimutagenic effects. Protective effects of G. gargal against DMBA are discussed in terms of the onset of desmutagenic and/or bioantimutagenic mechanisms of detoxification in the host organism, probably due to some bioactive compounds known to occur in higher mushrooms. PMID:22181846

Postemsky, Pablo Daniel; Palermo, Ana Maria; Curvetto, Néstor Raúl

2011-01-01

319

Plant Cell, Tissue and Organ Culture 73: 147157, 2003. 2003 Kluwer Academic Publishers. Printed in the Netherlands.  

E-print Network

. Printed in the Netherlands. A novel method to induce direct somatic embryogenesis, secondary embryogenesis, rye, species independent, wheat, wheat­wild grass amphiploids Abstract A direct somatic embryogenesis induction of direct somatic embryogenesis in barley (Hordeum vulgare), common wheat (Triticum aestivum

Selinger, Brent

320

Robotic workcell for quality sorting of somatic embryos  

NASA Astrophysics Data System (ADS)

Somatic embryogenesis is a process considered very promising in mass regeneration of plant materials. Quality evaluation of embryos' viability is deemed necessary during the process. Machine vision techniques have been or are being developed for quality sorting of embryos immediately before germination. In this project, a robotic workcell has been conceptually designed for quality sorting of somatic embryos employing machine vision system. The configuration of the workcell has been modeled using a 3D graphic modeling software package. The workcell component requirements, layout, and materials flow have been investigated for its workability. A numerical model has been developed to simulate the productivity of a workable layout. Some stochastic factors affecting the workcell productivity were considered in the numerical model. Engineering economic analysis was performed on the workcell for evaluating its cost-effectiveness.

Chen, F. S.; Ting, K. C.

1995-01-01

321

Influences of Aging on Taste Perception and Oral Somatic Sensation  

Microsoft Academic Search

Background. Many elderly persons report reduced taste perception of the foods they eat. Any disturbance of taste and oral somatic sensations can induce this phenomenon. To determine the cause of decreased taste perception in older persons, the authors investigated age-related changes in taste perception and somatic sensations in the anterior tongue. Methods. Thirty healthy young and elderly persons participated in

Akiko Fukunaga; Hiroshi Uematsu; Kumiko Sugimoto

2005-01-01

322

Development and germination of pecan somatic embryos derived from liquid culture  

Microsoft Academic Search

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

J. Austin Burns; Hazel Y. Wetzstein

1995-01-01

323

Colchicine-induced microspore embryogenesis in coffee  

Microsoft Academic Search

A protocol for the induction of androgenesis and plant regeneration from C. arabica cv. Caturra isolated microspores in vitro using colchicine pretreatment has been developed. Microspores were mechanically isolated and then carefully purified. Before colchicine pretreatment, microspores were cultured in a semi-solid medium for further develop and regeneration. Different times of colchicine exposure as well as different concentrations were tested.

J. C. Herrera; L. G. Moreno; J. R. Acuńa; M. De Peńa; D. Osorio

2002-01-01

324

N2O induces mitotic polyploidization in anther somatic cells and restores fertility in sterile interspecific hybrid lilies  

PubMed Central

Fertile plants undergoing male gametogenesis can be treated with nitrous oxide (N2O) gas to obtain 2n male gametes. N2O treatment is also expected to restore the fertility of interspecific hybrids through meiotic restitution or mitotic amphidiploidization. However, this technique has few applications to date, and it is un-known how N2O treatment restores fertility in sterile hybrids. To establish optimal N2O treatment conditions and determine its cytological mechanism of action, we treated various sized floral buds with N2O gas at different anther developmental stages from fertile and sterile hybrid lilies. N2O treatment using the optimal 1–4 mm floral buds induced mitotic polyploidization of male archesporial cells to produce 2n pollen in fertile hybrid lilies. In sterile hybrid lilies, N2O treatment doubled the chromosome number in male archesporial cells followed by homologous chromosome pairing and normal meiosis in pollen mother cells (PMC), resulting in restoration of pollen fertility. Backcrossing the resultant fertile pollen to Lilium × formolongi produced many triploid BC1 plants. Thus N2O treatment at the archesporial cell proliferating stage effectively overcame pollen sterility in hybrid lilies, resulting in fertile, 2n pollen grains that could produce progeny. The procedure presented here will promote interspecific or interploidy hybridization of lilies. PMID:23136469

Nukui, Shotarou; Kitamura, Satomi; Hioki, Tomoyo; Ootsuka, Hideaki; Miyoshi, Kazumitsu; Satou, Takao; Takatori, Yuka; Oomiya, Tomo; Okazaki, Keiichi

2011-01-01

325

Low Immunogenicity of Neural Progenitor Cells Differentiated from Induced Pluripotent Stem Cells Derived from Less Immunogenic Somatic Cells  

PubMed Central

The groundbreaking discovery of induced pluripotent stem cells (iPS cells) provides a new source for cell therapy. However, whether the iPS derived functional lineages from different cell origins have different immunogenicity remains unknown. It had been known that the cells isolated from extra-embryonic tissues, such as umbilical cord mesenchymal cells (UMCs), are less immunogenic than other adult lineages such as skin fibroblasts (SFs). In this report, we differentiated iPS cells from human UMCs and SFs into neural progenitor cells (NPCs) and analyzed their immunogenicity. Through co-culture with allologous peripheral blood mononuclear cells (PBMCs), we showed that UMCs were indeed less immunogenic than skin cells to simulate proliferation of PBMCs. Surprisingly, we found that the NPCs differentiated from UMC-iPS cells retained low immunogenicity as the parental UMCs based on the PBMC proliferation assay. In cytotoxic expression assay, reactions in most kinds of immune effector cells showed more perforin and granzyme B expression with SF-NPCs stimulation than that with UMC-NPCs stimulation in PBMC co-culture system, in T cell co-culture system as well. Furthermore, through whole genome expression microarray analysis, we showed that over 70 immune genes, including all members of HLA-I, were expressed at lower levels in NPCs derived from UMC-iPS cells than that from SF-iPS cells. Our results demonstrated a phenomenon that the low immunogenicity of the less immunogenic cells could be retained after cell reprogramming and further differentiation, thus provide a new concept to generate functional lineages with lower immunogenicity for regenerative medicine. PMID:23922758

Li, Xiang; Qin, Li; Huang, Ke; Wang, Lihui; Huang, Wenhao; Li, Shengbiao; Jia, Bei; Zhong, Mei; Pan, Guangjin; Cai, Jinglei; Pei, Duanqing

2013-01-01

326

Vitamin C deficiency improves somatic embryo development through distinct gene regulatory networks in Arabidopsis.  

PubMed

Changes in the endogenous ascorbate redox status through genetic manipulation of cellular ascorbate levels were shown to accelerate cell proliferation during the induction phase and improve maturation of somatic embryos in Arabidopsis. Mutants defective in ascorbate biosynthesis such as vtc2-5 contained ~70 % less cellular ascorbate compared with their wild-type (WT; Columbia-0) counterparts. Depletion of cellular ascorbate accelerated cell division processes and cellular reorganization and improved the number and quality of mature somatic embryos grown in culture by 6-fold compared with WT tissues. To gain insight into the molecular mechanisms underlying somatic embryogenesis (SE), we profiled dynamic changes in the transcriptome and analysed dominant patterns of gene activity in the WT and vtc2-5 lines across the somatic embryo culturing process. Our results provide insight into the gene regulatory networks controlling SE in Arabidopsis based on the association of transcription factors with DNA sequence motifs enriched in biological processes of large co-expressed gene sets. These data provide the first detailed account of temporal changes in the somatic embryo transcriptome starting with the zygotic embryo, through tissue dedifferentiation, and ending with the mature somatic embryo, and impart insight into possible mechanisms for the improved culture of somatic embryos in the vtc2-5 mutant line. PMID:25151615

Becker, Michael G; Chan, Ainsley; Mao, Xingyu; Girard, Ian J; Lee, Samantha; Elhiti, Mohamed; Stasolla, Claudio; Belmonte, Mark F

2014-11-01

327

Vitamin C deficiency improves somatic embryo development through distinct gene regulatory networks in Arabidopsis  

PubMed Central

Changes in the endogenous ascorbate redox status through genetic manipulation of cellular ascorbate levels were shown to accelerate cell proliferation during the induction phase and improve maturation of somatic embryos in Arabidopsis. Mutants defective in ascorbate biosynthesis such as vtc2-5 contained ~70 % less cellular ascorbate compared with their wild-type (WT; Columbia-0) counterparts. Depletion of cellular ascorbate accelerated cell division processes and cellular reorganization and improved the number and quality of mature somatic embryos grown in culture by 6-fold compared with WT tissues. To gain insight into the molecular mechanisms underlying somatic embryogenesis (SE), we profiled dynamic changes in the transcriptome and analysed dominant patterns of gene activity in the WT and vtc2-5 lines across the somatic embryo culturing process. Our results provide insight into the gene regulatory networks controlling SE in Arabidopsis based on the association of transcription factors with DNA sequence motifs enriched in biological processes of large co-expressed gene sets. These data provide the first detailed account of temporal changes in the somatic embryo transcriptome starting with the zygotic embryo, through tissue dedifferentiation, and ending with the mature somatic embryo, and impart insight into possible mechanisms for the improved culture of somatic embryos in the vtc2-5 mutant line. PMID:25151615

Becker, Michael G.; Chan, Ainsley; Mao, Xingyu; Girard, Ian J.; Lee, Samantha; Elhiti, Mohamed; Stasolla, Claudio; Belmonte, Mark F.

2014-01-01

328

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

329

From callus to embryo: a proteomic view on the development and maturation of somatic embryos in Cyclamen persicum.  

PubMed

In this study, the proteome structures following the pathway in somatic embryogenesis of Cyclamen persicum were analysed via high-resolution 2D-SDS-PAGE with two objectives: (1) to identify the significant physiological processes during somatic embryogenesis in Cyclamen and (2) to improve the maturation of somatic embryos. Therefore, the effects of maturation-promoting plant growth regulator abscisic acid (ABA) and high sucrose levels on torpedo-shaped embryos were investigated. In total, 108 proteins of differential abundance were identified using a combination of tandem mass spectrometry and a digital proteome reference map. In callus, enzymes related to energy supply were especially distinct, most likely due to energy demand caused by fast growth and cell division. The switch from callus to globular embryo as well as from globular to torpedo-shaped embryo was associated with controlled proteolysis via the ubiquitin-26S proteasome pathway. Storage compound accumulation was first detected 21 days after transfer to plant growth regulator (PGR)-free medium in early torpedo-shaped embryos. Increase in abundance of auxin-amidohydrolase during embryogenesis suggests a possible increase in auxin release in the late embryo stages of Cyclamen. A development-specific isoelectric point switch of catalases has been reported for the first time for somatic embryogenesis. Several proteins were identified to represent markers for the different developmental stages analysed. High sucrose levels and ABA treatment promoted the accumulation of storage compounds in torpedo-shaped embryos. Additionally, proteins of the primary metabolic pathways were decreased in the proteomes of ABA-treated embryos. Thus, ABA and high sucrose concentration in the culture medium improved maturation and consequently the quality of somatic embryos in C. persicum. PMID:22127736

Rode, Christina; Lindhorst, Kathrin; Braun, Hans-Peter; Winkelmann, Traud

2012-05-01

330

Discovery of genes expressed in Hydra embryogenesis  

Microsoft Academic Search

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

Grigory Genikhovich; Ulrich Kürn; Georg Hemmrich; Thomas C. G. Bosch

2006-01-01

331

Shusterman on Somatic Experience  

ERIC Educational Resources Information Center

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…

Maattanen, Pentti

2010-01-01

332

Selection of Norway spruce somatic embryos by computer vision  

NASA Astrophysics Data System (ADS)

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 somatic embryogenesis 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.

Hamalainen, Jari J.; Jokinen, Kari J.

1993-05-01

333

Genes directly regulated by LEAFY COTYLEDON2 provide insight into the control of embryo  

E-print Network

and somatic embryogenesis Siobhan A. Braybrook* , Sandra L. Stone*, Soomin Park*, Anhthu Q. Bui , Brandon H of somatic embryogenesis. Arabidopsis B3 domain Embryogenesis in higher plants can be divided conceptually) is required for several aspects of embryogenesis, including the maturation phase, and is sufficient to induce

Goldberg, Robert B.

334

MaSERK1 Gene Expression Associated with Somatic Embryogenic Competence and Disease Resistance Response in Banana ( Musa spp.)  

Microsoft Academic Search

A banana somatic embryogenesis receptor-like kinase (SERK) gene, designated as MaSERK1, was isolated from Musa acuminata cv. Mas (AA). It encoded a protein of 628 amino acids with above 82% identities to reported SERKs of coconut, rice, maize,\\u000a Arabidopsis, carrot, and Medicago truncatula. MaSERK1 was expressed weakly in male flower clusters, but not in male flower-derived nonembryogenic calli, but it

Xia Huang; Xiao-Yan Lu; Jie-Tang Zhao; Jie-Kai Chen; Xue-Mei Dai; Wang Xiao; Ya-Ping Chen; Yun-Feng Chen; Xue-Lin Huang

2010-01-01

335

Whole chromosome elimination and chromosome terminus elimination both contribute to somatic differentiation in Taiwanese hagfish Paramyxine sheni  

Microsoft Academic Search

Chromosome elimination is a process in which some chromatins are discarded from the presumptive somatic cells during early\\u000a embryogenesis. Eliminated chromatins in hagfish generally consist of repetitive sequences, and they are highly heterochromatinized\\u000a in germ cells. In this study, we characterized four novel eliminated DNA families, EEPs1–4, from the Taiwanese hagfish Paramyxine sheni. Sequences of these four elements occupied 20–27%

Noriko F. Kojima; Kenji K. Kojima; Shuichi Kobayakawa; Naoki Higashide; Chiemi Hamanaka; Ayumi Nitta; Ikuyo Koeda; Toru Yamaguchi; Motoharu Shichiri; Sei-ichi Kohno; Souichirou Kubota

2010-01-01

336

Periderm prevents pathological epithelial adhesions during embryogenesis  

PubMed Central

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

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

2014-01-01

337

Transcriptome Analysis of Zebrafish Embryogenesis Using Microarrays  

PubMed Central

Zebrafish (Danio rerio) is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula) revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition, a time point earlier than when the zygotic genome was traditionally thought to become active. Here we provide, for the first time to our knowledge, a comprehensive list of developmentally regulated zebrafish genes and their expression profiles during embryogenesis, including novel information on the temporal expression of several thousand previously uncharacterized genes. The expression data generated from this study are accessible to all interested scientists from our institute resource database (http://giscompute.gis.a-star.edu.sg/~govind/zebrafish/data_download.html). PMID:16132083

Mathavan, Sinnakaruppan; Lee, Serene G. P; Mak, Alicia; Miller, Lance D; Murthy, Karuturi Radha Krishna; Govindarajan, Kunde R; Tong, Yan; Wu, Yi Lian; Lam, Siew Hong; Yang, Henry; Ruan, Yijun; Korzh, Vladimir; Gong, Zhiyuan; Liu, Edison T; Lufkin, Thomas

2005-01-01

338

Checkpoint kinase 1 negatively regulates somatic hypermutation  

PubMed Central

Immunoglobulin (Ig) diversification by somatic hypermutation in germinal center B cells is instrumental for maturation of the humoral immune response, but also bears the risk of excessive or aberrant genetic changes. Thus, introduction of DNA damage by activation-induced cytidine deaminase as well as DNA repair by multiple pathways need to be tightly regulated during the germinal center response to prevent lymphomagenesis. In the present study, we show that DNA damage checkpoint signaling via checkpoint kinase 1 (Chk1) negatively regulates somatic hypermutation. Chk1 inhibition in human B cell lymphoma lines as well as inactivation of Chk1 alleles by gene targeting in DT40 B cells leads to increased somatic hypermutation. This is apparently due to changes in DNA repair pathways regulated by Chk1, such as a decreased homologous recombination efficiency that also leads to decreased Ig gene conversion in DT40. Our data show that Chk1 signaling plays a crucial role in regulation of Ig diversification and sheds unexpected light on potential origins of aberrant somatic hypermutation in B cell lymphomagenesis. PMID:24423870

Frankenberger, Samantha; Davari, Kathrin; Fischer-Burkart, Sabine; Böttcher, Katrin; Tomi, Nils-Sebastian; Zimber-Strobl, Ursula; Jungnickel, Berit

2014-01-01

339

Does DNA repair occur during somatic hypermutation?  

PubMed Central

Activation-induced deaminase (AID) initiates a flood of DNA damage in the immunoglobulin loci, leading to abasic sites, single-strand breaks and mismatches. It is compelling that some proteins in the canonical base excision and mismatch repair pathways have been hijacked to increase mutagenesis during somatic hypermutation. Thus, the AID-induced mutagenic pathways involve a mix of DNA repair proteins and low fidelity DNA polymerases to create antibody diversity. In this review, we analyze the roles of base excision repair, mismatch repair, and mutagenesis during somatic hypermutation of rearranged variable genes. The emerging view is that faithful base excision repair occurs simultaneously with mutagenesis, whereas faithful mismatch repair is mostly absent. PMID:22728014

Saribasak, Huseyin; Gearhart, Patricia J.

2012-01-01

340

ReproducedfromCropScience.PublishedbyCropScienceSocietyofAmerica.Allcopyrightsreserved. GENOMICS, MOLECULAR GENETICS  

E-print Network

, MOLECULAR GENETICS & BIOTECHNOLOGY Induction of Somatic Embryogenesis and Plant Regeneration in Select cultivars by backcross breeding (Trolinder, 1995). The via somatic embryogenesis. We tested 15 elite Upland by augmenting the use of genecapable of inducing somatic embryogenesis in diverse cotton species

Chee, Peng W.

341

Changes in the 2-DE protein profile during zygotic embryogenesis in the Brazilian Pine (Araucaria angustifolia).  

PubMed

Araucaria angustifolia is the only native conifer of economic importance in the Brazilian Atlantic Rainforest. Due to a clear-cutting form of exploitation this species has received the status of vulnerable. The aim of this work was to investigate and characterize changes in protein expression profile during seed development of this endangered species. For this, the proteome of developing seeds was characterized by 2-DE and LC-MS/MS. Ninety six proteins were confidently identified and classified according to their biological function and expression profile. Overaccumulated proteins in early seed development indicated a higher control on oxidative stress metabolism during this phase. In contrast, highly expressed proteins in late stages revealed an active metabolism, leading to carbon assimilation and storage compounds accumulation. Comprehensive protein expression profiles and identification of overaccumulated proteins provide new insights into the process of embryogenesis in this recalcitrant species. Considerations on the improvement and control of somatic embryogenesis through medium manipulation and protein markers screening using data generated are also discussed. PMID:19367732

Balbuena, Tiago S; Silveira, Vanildo; Junqueira, Magno; Dias, Leonardo L C; Santa-Catarina, Claudete; Shevchenko, Andrej; Floh, Eny I S

2009-04-13

342

Arabinogalactan protein profiles and distribution patterns during microspore embryogenesis and pollen development in Brassica napus.  

PubMed

Arabinogalactan proteins (AGPs), present in cell walls, plasma membranes and extracellular secretions, are massively glycosylated hydroxyproline-rich proteins that play a key role in several plant developmental processes. After stress treatment, microspores cultured in vitro can reprogramme and change their gametophytic developmental pathways towards embryogenesis, thereby producing embryos which can further give rise to haploid and double haploid plants, important biotechnological tools in plant breeding. Microspore embryogenesis constitutes a convenient system for studying the mechanisms underlying cell reprogramming and embryo formation. In this work, the dynamics of both AGP presence and distribution were studied during pollen development and microspore embryogenesis in Brassica napus, by employing a multidisciplinary approach using monoclonal antibodies for AGPs (LM2, LM6, JIM13, JIM14, MAC207) and analysing the expression pattern of the BnAGP Sta 39-4 gene. Results showed the developmental regulation and defined localization of the studied AGP epitopes during the two microspore developmental pathways, revealing different distribution patterns for AGPs with different antigenic reactivity. AGPs recognized by JIM13, JIM14 and MAC207 antibodies were related to pollen maturation, whereas AGPs labelled by LM2 and LM6 were associated with embryo development. Interestingly, the AGPs labelled by JIM13 and JIM14 were induced with the change of microspore fate. Increases in the expression of the Sta 39-4 gene, JIM13 and JIM14 epitopes found specifically in 2-4 cell stage embryo cell walls, suggested that AGPs are early molecular markers of microspore embryogenesis. Later, LM2 and LM6 antigens increased progressively with embryo development and localized on cell walls and cytoplasmic spots, suggesting an active production and secretion of AGPs during in vitro embryo formation. These results give new insights into the involvement of AGPs as potential regulating/signalling molecules in microspore reprogramming and embryogenesis. PMID:23729197

El-Tantawy, Ahmed-Abdalla; Solís, María-Teresa; Da Costa, Mario L; Coimbra, Silvia; Risueńo, María-Carmen; Testillano, Pilar S

2013-09-01

343

Gamete derivation from embryonic stem cells, induced pluripotent stem cells or somatic cell nuclear transfer-derived embryonic stem cells: state of the art.  

PubMed

Generating gametes from pluripotent stem cells (PSCs) has many scientific justifications and several biomedical rationales. Here, we consider several strategies for deriving gametes from PSCs from mice and primates (human and non-human) and their anticipated strengths, challenges and limitations. Although the 'Weismann barrier', which separates the mortal somatic cell lineages from the potentially immortal germline, has long existed, breakthroughs first in mice and now in humans are artificially creating germ cells from somatic cells. Spermatozoa with full reproductive viability establishing multiple generations of seemingly normal offspring have been reported in mice and, in humans, haploid spermatids with correct parent-of-origin imprints have been obtained. Similar progress with making oocytes has been published using mouse PSCs differentiated in vitro into primordial germ cells, which are then cultured after xenografting reconstructed artificial ovaries. Progress in making human oocytes artificially is proving challenging. The usefulness of these artificial gametes, from assessing environmental exposure toxicity to optimising medical treatments to prevent negative off-target effects on fertility, may prove invaluable, as may basic discoveries on the fundamental mechanisms of gametogenesis. PMID:25472048

Easley, Charles A; Simerly, Calvin R; Schatten, Gerald

2014-12-01

344

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

Microsoft Academic Search

Brassica napus cultivar Westar is non-embryogenic under all standard protocols for induction of micro- spore embryogenesis; however, the rare embryos pro- duced 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

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

2008-01-01

345

Somatic embryogenesis in cultured immature kernels of Pistachio, Pistacia vera L  

Microsoft Academic Search

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

A. Onay; C. E. Jeffree; M. M. Yeoman

1995-01-01

346

Silver nitrate and 2-isopentyladenine promote somatic embryogenesis in date palm ( Phoenix dactylifera L.)  

Microsoft Academic Search

Embryogenic callus derived from offshoot tip of date palm (Phoenix dactylifera L.) was transferred to MS medium containing 0, 25, 50, 75, or 100?M AgNO3 combined with 0 or 0.5?M 2iP. Embryogenic callus weight, number of embryos developed and embryo elongation were significantly influenced by the interaction between silver nitrate (AgNO3) and 2iP. In the absence of 2iP, callus weight

Jameel M Al-Khayri; Abdulaziz M Al-Bahrany

2001-01-01

347

Influence of physical conditions of nutrient medium and sucrose on somatic embryogenesis of date palm  

Microsoft Academic Search

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

J. Veramendi; L. Navarro

1996-01-01

348

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

Microsoft Academic Search

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

2000-01-01

349

INDUCTION OF SOMATIC EMBRYOGENESIS IN O'HENRY CULTIVAR OF PEACH (PRUNUS PERSICA)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The peach industry plays an important role in the agricultural economy of the southeastern United States, annually producing 35% of the American peach crop. Peach tree short life (PTSL) syndrome results in the drastic decline in peach tree population and orchard longevity. It prematurely kills trees...

350

Somatic embryogenesis and plant regeneration from leaf tissues and anthers of Pennisetum purpureum Schum  

Microsoft Academic Search

Expiants obtained from leaves of Pennisetum purpureum Schum. gave rise to callus tissues when cultured on Murashige and Skoog's nutrient medium containing only 2,4-dichlorophenoxyacetic acid (2,4-D), or 2,4-D supplemented with naphthalene-acetic acid and\\/or 6-benzylaminopurine. Embryoids were formed in the white, compact and highly organised areas of the callus and developed into plants. Histological examination of cultured leaf segments showed that

Z. Haydu; I. K. Vasil

1981-01-01

351

Plantlet regeneration via somatic embryogenesis from subcultured callus of mature embryos of Picea abies (Norway spruce)  

Microsoft Academic Search

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

Pramod K. Gupta; Don J. Durzan

1986-01-01

352

Arabinogalactan proteins are essential in somatic embryogenesis of Daucus carota L  

Microsoft Academic Search

Daucus carota L. cell lines secrete a characteristic set of arabinogalactan proteins (AGPs) into the medium. The composition of this set of AGPs changes with the age of the culture, as can be determined by crossed electrophoresis with the specific AGP-binding agent, ß-glucosyl Yariv reagent. Addition of AGPs isolated from the medium of a non-embryogenic cell line to an expiant

Marc Kreuger; Gerrit-Jan van Hoist

1993-01-01

353

Characterization of somatic embryogenesis and plant regeneration in cotton ( Gossypium hirsutum L.)  

Microsoft Academic Search

Seventeen cultivars of cotton (Gossypium hirsutum L.) were evaluated for callus initiation and maintenance using 3 initiation media and 3 maintenance media. After a series of transfers of a 3% glucose media, calli were placed on a 3% sucrose medium. After several weeks calli were observed for the presence of embryo-like structures. Cultivars Coker 201 and Coker 315 were identified

R. C. Shoemaker; L. J. Couche; D. W. Galbraith

1986-01-01

354

Somatic embryogenesis and plant regeneration in tissue cultures of sweet potato ( Ipomea batatas Poir.)  

Microsoft Academic Search

Leaf, shoot-tip, stem, and root explants of sweet potato (Ipomea batatas Poir.) gave rise to two kinds of callus on nutrient agar medium containing 0.5 to 2.0 mg\\/l 2,4-D. One callus, bright- to\\u000a pale-yellow, was compact and organized, while the other was dull-yellow and friable. The former callus gave rise to numerous\\u000a globular and heart-shaped embryoids. When transferred onto hormone-free

Jang R. Liu; Daniel J. Cantliffe

1984-01-01

355

Plant regeneration via somatic embryogenesis in many cultivars of cotton ( Gossypium hirsutum L.)  

Microsoft Academic Search

Summary  Embryogenic callus was formed from several cultivars of cotton (Gossypium hirsutum L.) when sections of hypocotyl and cotyledon were cultured on medium supplemented with 5 mg\\/liter 6-(?, ?-dimethylallyl-amino)-purine\\u000a (2iP) and 0.1 mg\\/liter ?-naphthaleneacetic acid (NAA) for callus initiation and proliferation, and subcultured on medium supplemented\\u000a with 5 mg\\/liter NAA and 0.1 to 1 mg\\/liter 2iP for embryogenic callus induction. It

E. Firoozabady; D. L. DeBoer

1993-01-01

356

Somatic embryogenesis in cotton (Gossypium). II. Requirements for embryo development and plant regeneration  

Microsoft Academic Search

Calli of cotton (Gossypium hirsutum L.) initiated from seedling hypocotyl tissue were placed in liquid suspension and maintained by serial subculture in hormone-free Murashige and Skoog (MS) medium. Suspensions were sieved and globular embryos collected, washed, resuspended in basal medium and plated onto various semi-solid media. High inorganic salts (MS), low salt (2\\/3 MS), excess KNO3, and the growth regulators

Norma L. Trolinder; J. R. Goodin

1988-01-01

357

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

Microsoft Academic Search

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

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

1994-01-01

358

Somatic embryogenesis and somaclonal variation in Norway spruce: morphogenetic, cytogenetic and molecular approaches  

Microsoft Academic Search

Four embryogenic clones of Norway spruce have been subcultivated and observed over several years to determine the evolution\\u000a of production of mature embryos and to assess the quality of the embryos produced. A wide range of intraclonal quantitative\\u000a and qualitative variability has been observed within this production. Certain morphologic deviations appeared at the immature\\u000a stage and after maturation, such as

J.-L. Fourré; P. Berger; L. Niquet; P. André

1997-01-01

359

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

Microsoft Academic Search

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

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

1993-01-01

360

Embryogenesis and plant regeneration of pakchoi ( Brassica rapa L. ssp. chinensis) via in vitro isolated microspore culture  

Microsoft Academic Search

Isolated microspores of various populations of three varieties of the Chinese cabbage pakchoi (Brassica rapa ssp. chinensis) were cultivated in vitro on NLN82 medium (Lichter 1982) and embryos and plantlets obtained with nine cultivars. The best embryo yield per bud was 57.4. A 33°C one day heat treatment was generally necessary to induce embryogenesis. Analysis of ploidy level through flow

Ming Qing Cao; Yan Li; Fan Liu; Claire Doré

1994-01-01

361

The p53-induced lincRNA-p21 derails somatic cell reprogramming by sustaining H3K9me3 and CpG methylation at pluripotency gene promoters.  

PubMed

Recent studies have boosted our understanding of long noncoding RNAs (lncRNAs) in numerous biological processes, but few have examined their roles in somatic cell reprogramming. Through expression profiling and functional screening, we have identified that the large intergenic noncoding RNA p21 (lincRNA-p21) impairs reprogramming. Notably, lincRNA-p21 is induced by p53 but does not promote apoptosis or cell senescence in reprogramming. Instead, lincRNA-p21 associates with the H3K9 methyltransferase SETDB1 and the maintenance DNA methyltransferase DNMT1, which is facilitated by the RNA-binding protein HNRNPK. Consequently, lincRNA-p21 prevents reprogramming by sustaining H3K9me3 and/or CpG methylation at pluripotency gene promoters. Our results provide insight into the role of lncRNAs in reprogramming and establish a novel link between p53 and heterochromatin regulation. PMID:25512341

Bao, Xichen; Wu, Haitao; Zhu, Xihua; Guo, Xiangpeng; Hutchins, Andrew P; Luo, Zhiwei; Song, Hong; Chen, Yongqiang; Lai, Keyu; Yin, Menghui; Xu, Lingxiao; Zhou, Liang; Chen, Jiekai; Wang, Dongye; Qin, Baoming; Frampton, Jon; Tse, Hung-Fat; Pei, Duanqing; Wang, Huating; Zhang, Biliang; Esteban, Miguel A

2015-01-01

362

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

Microsoft Academic Search

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

B. K. VIG

1973-01-01

363

Genetic Regulatory Networks in Embryogenesis and Evolution  

NASA Technical Reports Server (NTRS)

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 and body plan evolution, changes in cell lineage specification elucidate evolutionary relations in spiralia, axial patterning in the leech: developmental mechanisms and evolutionary implications, hox genes in arthropod development and evolution, heterochronic genes in development and evolution, a common theme for LIM homeobox gene function across phylogeny, and mechanisms of specification in ascidian embryos.

1998-01-01

364

Embryogenesis of brassica rapa l. under clinorotation  

NASA Astrophysics Data System (ADS)

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.

Popova, A.; Ivanenko, G.

365

Real-time Embryogenesis in Live Caenorhabditis elegans Worms  

NSDL National Science Digital Library

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)

2011-11-21

366

Intravenous somatic gene transfer with antisense tissue factor restores blood flow by reducing tumor necrosis factor-induced tissue factor expression and fibrin deposition in mouse meth-A sarcoma.  

PubMed Central

Fibrin is deposited on the endothelial cell surface in the vasculature of murine methylcholanthrene A-induced sarcomas after injection of tumor necrosis factor (TNF). Capillary endothelial cells of the tumor vascular bed become positive for tissue factor after TNF injection, based on immunocytochemistry and in situ hybridization. Intravascular clot formation was not dependent on tissue factor derived from tumor cells, since in vessels of tumors not expressing tissue factor, TNF also induced fibrin/fibrinogen deposition. However, the time course of fibrin/fibrinogen deposition after TNF differed in tumors expressing no, little, or greater amounts of tissue factor. Fibrin/fibrinogen deposition was more rapid in tumors in which the neoplastic cells expressed tissue factor than in tumors not expressing tissue factor. In the tumors not expressing tissue factor, activation of coagulation was dependent on TNF-induced synthesis of tissue factor by host cells, i.e., endothelium or monocytes/macrophages. Intravenous somatic gene transfer with tissue factor cDNA in the antisense orientation (but not sense or vector alone) reduced intravascular fibrin/fibrinogen deposition and restored blood flow to the tumor, showing that de novo tissue factor expression is central in TNF-induced activation of the coagulation mechanism. PMID:8636400

Zhang, Y.; Deng, Y.; Wendt, T.; Liliensiek, B.; Bierhaus, A.; Greten, J.; He, W.; Chen, B.; Hach-Wunderle, V.; Waldherr, R.; Ziegler, R.; Männel, D.; Stern, D. M.; Nawroth, P. P.

1996-01-01

367

Somatic embryo-like structures of strawberry regenerated in vitro on media supplemented with 2,4-D and BAP.  

PubMed

Somatic embryo-like structures (SELS) were produced in vitro from leaf disk and petiole explants of two cultivars of strawberry (Fragaria x ananassa Duch) on Murashige and Skoog medium with different concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and sucrose to check the embryonic nature of these structures histologically. A large number of SELS could be regenerated in both cultivars on media with 2-4 mg L(-1) 2,4-D in combination with 0.5 -1 mg L(-1) BAP and 50 g x L(-1) sucrose. Histological examination of SELS revealed the absence of a root pole. Therefore these structures cannot be strictly classified as somatic embryos. The SELS formed under the tested culture conditions represent malformed shoot-like and leaf-like structures. The importance of these results for the propagation of strawberries via somatic embryogenesis is discussed. PMID:24377134

Omar, Genesia F; Mohamed, Fouad H; Haensch, Klaus-Thomas; Sarg, Sawsan H; Morsey, Mohamed M

2013-09-01

368

High Genetic and Epigenetic Stability in Coffea arabica Plants Derived from Embryogenic Suspensions and Secondary Embryogenesis as Revealed by AFLP, MSAP and the Phenotypic Variation Rate  

PubMed Central

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 somatic embryogenesis-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 somatic embryogenesis. 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. PMID:23418563

Bobadilla Landey, Roberto; Cenci, Alberto; Georget, Frédéric; Bertrand, Benoît; Camayo, Gloria; Dechamp, Eveline; Herrera, Juan Carlos; Santoni, Sylvain; Lashermes, Philippe; Simpson, June; Etienne, Hervé

2013-01-01

369

Ophiobolin A from Bipolaris oryzae Perturbs Motility and Membrane Integrities of Porcine Sperm and Induces Cell Death on Mammalian Somatic Cell Lines  

PubMed Central

Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1–2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration. PMID:25251540

Bencsik, Ottó; Papp, Tamás; Berta, Máté; Zana, Annamária; Forgó, Péter; Dombi, György; Andersson, Maria A.; Salkinoja-Salonen, Mirja; Vágvölgyi, Csaba; Szekeres, András

2014-01-01

370

Ophiobolin A from Bipolaris oryzae perturbs motility and membrane integrities of porcine sperm and induces cell death on mammalian somatic cell lines.  

PubMed

Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1-2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration. PMID:25251540

Bencsik, Ottó; Papp, Tamás; Berta, Máté; Zana, Annamária; Forgó, Péter; Dombi, György; Andersson, Maria A; Salkinoja-Salonen, Mirja; Vágvölgyi, Csaba; Szekeres, András

2014-09-01

371

The effects of microgravity on gametogenesis, fertilization, and early embryogenesis  

NASA Astrophysics Data System (ADS)

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

Tan, X.

372

ARTICLE doi:10.1038/nature09805 Somatic coding mutations in human  

E-print Network

ARTICLE doi:10.1038/nature09805 Somatic coding mutations in human induced pluripotent stem cells, and could carry a mutational load due to normal in vivo somatic mutation. Furthermore, many hiPS cell repro- gramming methods use oncogenes that may increase the mutation rate. Additionally, some hiPS cell lines have

Church, George M.

373

Isolation and characterization of a molecule stimulatory to growth of somatic embryos from early stage female gametophyte tissue of loblolly pine  

Microsoft Academic Search

Loblolly pine (LP, Pinus taeda) is the primary commercial species in southern forests of the US. Somatic embryogenesis (SE) is an effective technique to\\u000a implement clonal tree production of high-value genotypes from breeding and genetic engineering programs. Unlike angiosperm\\u000a embryos with attached cotyledons as seed storage organs, the diploid conifer embryo is surrounded by the unattached haploid\\u000a female gametophyte (FG).

Veronica De Silva; David Bostwick; Kristi L. Burns; Charlie D. Oldham; Anna Skryabina; M. Cameron Sullards; Di Wu; Yalin Zhang; Sheldon W. May; Gerald S. Pullman

2008-01-01

374

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

PubMed Central

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

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

2008-01-01

375

Mechanisms and models of somatic cell reprogramming  

PubMed Central

Conversion of somatic cells to pluripotency by defined factors is a long and complex process that yields embryonic stem cell-like cells that vary in their developmental potential. To improve the quality of resulting induced pluripotent stem cells (iPSCs), which is important for potential therapeutic applications, and to address fundamental questions about control of cell identity, molecular mechanisms of the reprogramming process must be understood. Here we discuss recent discoveries regarding the role of reprogramming factors in remodeling the genome, including new insights into the function of c-Myc, and describe the different phases, markers and emerging models of reprogramming. PMID:23681063

Buganim, Yosef; Faddah, Dina A.; Jaenisch, Rudolf

2014-01-01

376

The freshwater planarian Schmidtea mediterranea: embryogenesis, stem cells and regeneration  

E-print Network

The freshwater planarian Schmidtea mediterranea: embryogenesis, stem cells and regeneration function in planarians during development and regeneration. These advances promise to shed mechanistic Commentary Alejandro Sa´ nchez Alvarado Planarians have been used as a model to study development

Alvarado, Alejandro Sánchez

377

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

SciTech Connect

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)

1994-09-01

378

Cryopreservation of zygotic embryo axes and somatic embryos of European chestnut.  

PubMed

This work describes experiments demonstrating the feasibility of long-term conservation of Castanea sativa germplasm through cryopreservation of embryonic axes or somatic embryo clumps. Between 93 % and 100 % of excised embryonic axes of recalcitrant chestnut seeds survived storage in liquid nitrogen (LN) following desiccation in a laminar flow cabinet to moisture contents of 20-24 % (on a fresh weight basis), and some 63 % subsequently developed as whole plants. Desiccation to moisture contents less than 19 % produced damage resulting in loss of organized plant development after cryostorage, allowing only root growth. When 6-8 mg clumps of globular or heart-shaped somatic embryos were precultured for 7 days on high-sucrose medium and then desiccated to a moisture content of 25 % before storage in LN, the embryogenesis resumption level after thawing was 33 %. When the embryo clumps were precultured for 3 days on high-sucrose medium followed by 60 min application of PVS2 vitrification solution before cryostorage, the post-storage embryogenesis resumption level was 68 %. PMID:15031743

Corredoira, Elena; San-José, M Carmen; Ballester, Antonio; Vieitez, Ana M

2004-01-01

379

Somatic cell mutagenesis in Drosophila: recovery of genetic damage in relation to the types of DNA lesions induced in mutationally unstable and stable X-chromosomes.  

PubMed

This paper reports the results of a study on the genotoxic activities of 12 mutagens and clastogens of widely differing mode of action in somatic cells in vivo, i.e., in the eye primordia of Drosophila larvae. After emergence, adult flies were monitored for aberrantly colored sectors in the compound eyes of the following genotypes: UZ males and females (zeste) carrying a genetically unstable transposable element, SZ males and females (zeste) carrying a partial duplication of the w+ locus plus a transposon insert, white-coral/white (wco/w) females, w+/w females and w+ males. The UZ and SZ marker sets make it possible to monitor shifts from zeste to red (scored as mosaic red spots, RS) and for loss of the white locus (light spots, LS). wco/w+ females were scored for mosaic twin spots (TS) and LS, w+ genotypes for just LS. The genotoxins analyzed were methyl methanesulfonate (MMS), dimethyl sulfate (DMS) and ethylnitrosourea (ENU) (alkylating), adriamycin (AM) and daunomycin (DM) (intercalating), Trenimon, Thio-TEPA and cisplatin (DDP) (cross-linking), bleomycin (strand-breaking), 7,12-dimethylbenz[a]anthracene (DMBA) and 9,10-dimethylanthracene (DA) (bulky monoadducts) and cytosine arabinofuranoside (inhibition of DNA synthesis). The relative mutabilities with frequencies of mosaic light spots (LS) in w+/w female as the standard (relative mutability = 1) vs. genotypes UZ (RS in male) vs. SZ (RS in male) vs. w+ (LS in male) were 1:0.6:0.2:0.3 for MMS, 1:0.09:0.05:0.7 for DDP, and 1:1.6:0.2:1.0 for ENU, ENU showed exceptional behavior in that it was the only compound for which mutational response, measured by the induction of red spots, was highest with the UZ marker set. Occurrence of large light spots (LS) in male but not in female genotypes was negatively correlated with efficiency of agents for chromosomal damage, suggesting that in the hemizygous condition, as in males, selection of damaged cells and mitotic delay may have played a significant role. In general, the results indicate that there is no association between the ability of an agent to act as a clastogen and the recovery of aberrant (red spots) sectors in either the UZ or the SZ strain, and of single light spots (LS) in w+, UZ and SZ males. The possibility is considered that the process causing the genetic instability in the UZ strain is under genetic control, and that strong point mutagens such as ENU through efficient gene mutation induction can interfere with it. PMID:2466199

Vogel, E W

1989-03-01

380

Gene expression throughout a vertebrate's embryogenesis  

PubMed Central

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. PMID:21356103

2011-01-01

381

Metabolome Analysis of Drosophila melanogaster during Embryogenesis  

PubMed Central

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos’ metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo. PMID:25121768

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

382

Environmental magnetic fields: Influences on early embryogenesis  

SciTech Connect

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))

1993-04-01

383

Drosophila Embryogenesis Scales Uniformly across Temperature in Developmentally Diverse Species  

PubMed Central

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

Kuntz, Steven G.; Eisen, Michael B.

2014-01-01

384

Reprogramming somatic cells to pluripotency  

PubMed Central

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

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

2013-01-01

385

Histone variant macroH2A marks embryonic differentiation in vivo and acts as an epigenetic barrier to induced pluripotency  

PubMed Central

Summary How cell fate becomes restricted during somatic cell differentiation is a long-lasting question in biology. Epigenetic mechanisms not present in pluripotent cells and acquired during embryonic development are expected to stabilize the differentiated state of somatic cells and thereby restrict their ability to convert to another fate. The histone variant macroH2A acts as a component of an epigenetic multilayer that heritably maintains the silent X chromosome and has been shown to restrict tumor development. Here we show that macroH2A marks the differentiated cell state during mouse embryogenesis. MacroH2A.1 was found to be present at low levels upon the establishment of pluripotency in the inner cell mass and epiblast, but it was highly enriched in the trophectoderm and differentiated somatic cells later in mouse development. Chromatin immunoprecipitation revealed that macroH2A.1 is incorporated in the chromatin of regulatory regions of pluripotency genes in somatic cells such as mouse embryonic fibroblasts and adult neural stem cells, but not in embryonic stem cells. Removal of macroH2A.1, macroH2A.2 or both increased the efficiency of induced pluripotency up to 25-fold. The obtained induced pluripotent stem cells reactivated pluripotency genes, silenced retroviral transgenes and contributed to chimeras. In addition, overexpression of macroH2A isoforms prevented efficient reprogramming of epiblast stem cells to naďve pluripotency. In summary, our study identifies for the first time a link between an epigenetic mark and cell fate restriction during somatic cell differentiation, which helps to maintain cell identity and antagonizes induction of a pluripotent stem cell state. PMID:23077180

Pasque, Vincent; Radzisheuskaya, Aliaksandra; Gillich, Astrid; Halley-Stott, Richard P.; Panamarova, Maryna; Zernicka-Goetz, Magdalena; Surani, M. Azim; Silva, José C. R.

2012-01-01

386

Somatic Treatments for Mood Disorders  

Microsoft Academic Search

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

Moacyr A Rosa; Sarah H Lisanby

2012-01-01

387

[Functional somatization: a conceptual review].  

PubMed

The authors have brought together and analised texts about the history of the concept of hysteria. In these texts hysteria is fundamentally considered a disease of organic origin (of the womb), and, in the Middle Age, evidence of demonic possession. From the XVII century onwards, apart from the etiopathogenic concepts, also taken into consideration are aspects connected to the differential diagnosis with other similar entities and the therapy used each period. Even, in subsequent centuries, authors such as Syndenham, who consider hysteria to be a multidimensional entity, are rare. Empiricism has contributed to discoveries in biology and physiology, both general and of the nervous system itself, and given birth to the formulation of the Spinal Irritation Theory and Reflex Theory. These theories have led to strictly organic treatment of hysteria, in the same way that hysterectomies were performed to alleviate somatic symptoms connected to this disease. The introduction of hypnosis in medical practice, with Charcot in X1X century, allowed for the element of suggestion to be observed ( a non organic element) which accompanies the symptoms of hysteria. Two of his disciples, Janet and Freud, would define and isolate psychic mechanisms in the symptoms of hysteria: Dissociation of the consciousness (Janet) and Conversion (Freud). The last one developed a therapeutic method of a psychological nature for hysteria. The therapeutic implications and the pertinence of the distinction between unspecific somatization or functional (of somatic origin) somatization and somatization linked to disassociation mechanisms and conversion (psychic origin) are discussed as well as the evolution of international classification systems of somatization and the questions posed by the algorithms chosen for the cataloguing of symptoms. A revision of the relevant empirical studies about the association of somatization with depressive and anxiety disorders, within the general population, is made. The characteristics that permeate the clinical descriptions of somatoform disorders (whose validity criteria remain weak) and are not integrated within the diagnostic criteria for somatoform disorders are considered. We draw conclusions about the difficulties and consequences of the changes that some authors advocate in relation to the new classification system for somatoform syndromes. PMID:22525627

Fabiăo, Cristina; Fleming, Manuela; Barbosa, António

2011-01-01

388

Photodynamic inactivation of somatic frog nerve ex vivo  

NASA Astrophysics Data System (ADS)

New techniques research mechanisms of photdynamic reactions at somatic frog nerve was approved. Dosimetry PDT with minimum time resolution ~1ms determined by changing the amplitude of compound action potential of somatic frog nerve. Light-induced inactivation of dynamic response of somatic frog nerve on electrical pulsed excitation was study ex vivo. The light-sensitive dyes: methylene blue (Mb), Indocianin green and eryhtrocin-B has been used on photodynamic induced inactivation of the processes generation nerve pulses. Inactivation of consequence action potential of somatic frog nerve using excitation of electical pulsed was achieved by irradiation with He-Ne laser light in a red spectral region (?=633 nm, power level 2-20 mW), diode laser (?=805 nm, P<0.1-1 W/cm2) in the case of Indocianin green and YAG:Nd laser (?=532 nm, P~1mW) for eryhtrocin-B. It was discovered that methylene blue, Indocainine green and erytrocin-B decrease of the amplitude compound action potential of the ensemble neurons. The possible cell death mechanism was connected with damage of the sodium potassium adenosine triphosphatase (K-Na ATP) active transport which decrease of amplitude of compound action potential and decrease lifetime ionic channel of membrane nerve.

Akchurin, Garif G.; Seliverstov, George A.; Akchurin, George G.; Kudryashova, Svetlana Y.

2004-06-01

389

Genotoxic effects of cisplatin in somatic tissue of Drosophila melanogaster  

SciTech Connect

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.

Katz, A.J.

1987-01-01

390

Somatic mutations in cancer development  

PubMed Central

The transformation of a normal cell into a cancer cell takes place through a sequence of a small number of discrete genetic events, somatic mutations: thus, cancer can be regarded properly as a genetic disease of somatic cells. The analogy between evolution of organisms and evolution of cell populations is compelling: in both cases what drives change is mutation, but it is Darwinian selection that enables clones that have a growth advantage to expand, thus providing a larger target size for the next mutation to hit. The search for molecular lesions in tumors has taken on a new dimension thanks to two powerful technologies: the micro-arrays for quantitative analysis of global gene expresssion (the transcriptome); and ‘deep’ sequencing for the global analysis of the entire genome (or at least the exome). The former offers the most complete phenotypic characterization of a tumor we could ever hope for – we could call this the ultimate phenotype; the latter can identify all the somatic mutations in an individual tumor – we could call this the somatic genotype. However, there is definitely the risk that while we are ‘drowned by data, we remain thirsty for knowledge’. If we want to heed the teachings of Lorenzo Tomatis, I think the message is clear: we ought to take advantage of the new powerful technologies – not by becoming their slaves, but remaining their masters. Identifying somatic mutations in a tumor is important not because it qualifies for ‘oncogenomics’, but because through a deeper understanding of the nature of that particular tumor it can help us to optimize therapy or to design new therapeutic approaches. PMID:21489208

2011-01-01

391

Somatic mutations in cancer development.  

PubMed

The transformation of a normal cell into a cancer cell takes place through a sequence of a small number of discrete genetic events, somatic mutations: thus, cancer can be regarded properly as a genetic disease of somatic cells. The analogy between evolution of organisms and evolution of cell populations is compelling: in both cases what drives change is mutation, but it is Darwinian selection that enables clones that have a growth advantage to expand, thus providing a larger target size for the next mutation to hit. The search for molecular lesions in tumors has taken on a new dimension thanks to two powerful technologies: the micro-arrays for quantitative analysis of global gene expresssion (the transcriptome); and 'deep' sequencing for the global analysis of the entire genome (or at least the exome). The former offers the most complete phenotypic characterization of a tumor we could ever hope for--we could call this the ultimate phenotype; the latter can identify all the somatic mutations in an individual tumor--we could call this the somatic genotype. However, there is definitely the risk that while we are 'drowned by data, we remain thirsty for knowledge'. If we want to heed the teachings of Lorenzo Tomatis, I think the message is clear: we ought to take advantage of the new powerful technologies--not by becoming their slaves, but remaining their masters. Identifying somatic mutations in a tumor is important not because it qualifies for 'oncogenomics', but because through a deeper understanding of the nature of that particular tumor it can help us to optimize therapy or to design new therapeutic approaches. PMID:21489208

Luzzatto, Lucio

2011-01-01

392

Generation of Leukemia Inhibitory Factor and Basic Fibroblast Growth Factor-Dependent Induced Pluripotent Stem Cells from Canine Adult Somatic Cells  

PubMed Central

For more than thirty years, the dog has been used as a model for human diseases. Despite efforts made to develop canine embryonic stem cells, success has been elusive. Here, we report the generation of canine induced pluripotent stem cells (ciPSCs) from canine adult fibroblasts, which we accomplished by introducing human OCT4, SOX2, c-MYC, and KLF4. The ciPSCs expressed critical pluripotency markers and showed evidence of silencing the viral vectors and normal karyotypes. Microsatellite analysis indicated that the ciPSCs showed the same profile as the donor fibroblasts but differed from cells taken from other dogs. Under culture conditions favoring differentiation, the ciPSCs could form cell derivatives from the ectoderm, mesoderm, and endoderm. Further, the ciPSCs required leukemia inhibitory factor and basic fibroblast growth factor to survive, proliferate, and maintain pluripotency. Our results demonstrate an efficient method for deriving canine pluripotent stem cells, providing a powerful platform for the development of new models for regenerative medicine, as well as for the study of the onset, progression, and treatment of human and canine genetic diseases. PMID:21495906

Luo, Jiesi; Suhr, Steven T.; Chang, Eun Ah; Wang, Kai; Ross, Pablo J.; Nelson, Laura L.; Venta, Patrick J.; Knott, Jason G.

2011-01-01

393

Plant regeneration of Korean wild ginseng (Panax ginseng Meyer) mutant lines induced by ?-irradiation (60Co) of adventitious roots  

PubMed Central

An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic callus proliferation and somatic embryo induction occurred on MS medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid. The induced somatic embryos further developed to maturity on MS medium with 5 mg/L gibberellic acid, and 85% of them germinated. The germinated embryos were developed to shoots and elongated on MS medium with 5 mg/L gibberellic acid. The shoots developed into plants with well-developed taproots on one-third strength Schenk and Hildebrandt basal medium supplemented with 0.25 mg/L 1-naphthaleneacetic acid. When the plants were transferred to soil, about 30% of the regenerated plants developed into normal plants. PMID:25378998

Zhang, Jun-Ying; Sun, Hyeon-Jin; Song, In-Ja; Bae, Tae-Woong; Kang, Hong-Gyu; Ko, Suk-Min; Kwon, Yong-Ik; Kim, Il-Woung; Lee, Jaechun; Park, Shin-Young; Lim, Pyung-Ok; Kim, Yong Hwan; Lee, Hyo-Yeon

2014-01-01

394

Plant regeneration of Korean wild ginseng (Panax ginseng Meyer) mutant lines induced by ?-irradiation ((60)Co) of adventitious roots.  

PubMed

An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic callus proliferation and somatic embryo induction occurred on MS medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid. The induced somatic embryos further developed to maturity on MS medium with 5 mg/L gibberellic acid, and 85% of them germinated. The germinated embryos were developed to shoots and elongated on MS medium with 5 mg/L gibberellic acid. The shoots developed into plants with well-developed taproots on one-third strength Schenk and Hildebrandt basal medium supplemented with 0.25 mg/L 1-naphthaleneacetic acid. When the plants were transferred to soil, about 30% of the regenerated plants developed into normal plants. PMID:25378998

Zhang, Jun-Ying; Sun, Hyeon-Jin; Song, In-Ja; Bae, Tae-Woong; Kang, Hong-Gyu; Ko, Suk-Min; Kwon, Yong-Ik; Kim, Il-Woung; Lee, Jaechun; Park, Shin-Young; Lim, Pyung-Ok; Kim, Yong Hwan; Lee, Hyo-Yeon

2014-07-01

395

Marker genes identify three somatic cell types in the fetal mouse ovary.  

PubMed

The two main functions of the ovary are the production of oocytes, which allows the continuation of the species, and secretion of female sex hormones, which control many aspects of female development and physiology. Normal development of the ovaries during embryogenesis is critical for their function and the health of the individual in later life. Although the adult ovary has been investigated in great detail, we are only starting to understand the cellular and molecular biology of early ovarian development. Here we show that the adult stem cell marker Lgr5 is expressed in the cortical region of the fetal ovary and this expression is mutually exclusive to FOXL2. Strikingly, a third somatic cell population can be identified, marked by the expression of NR2F2, which is expressed in LGR5- and FOXL2 double-negative ovarian somatic cells. Together, these three marker genes label distinct ovarian somatic cell types. Using lineage tracing in mice, we show that Lgr5-positive cells give rise to adult cortical granulosa cells, which form the follicles of the definitive reserve. Moreover, LGR5 is required for correct timing of germ cell differentiation as evidenced by a delay of entry into meiosis in Lgr5 loss-of-function mutants, demonstrating a key role for LGR5 in the differentiation of pre-granulosa cells, which ensure the differentiation of oogonia, the formation of the definitive follicle reserve, and long-term female fertility. PMID:25158167

Rastetter, Raphael H; Bernard, Pascal; Palmer, James S; Chassot, Anne-Amandine; Chen, Huijun; Western, Patrick S; Ramsay, Robert G; Chaboissier, Marie-Christine; Wilhelm, Dagmar

2014-10-15

396

Introduction Building tissues and organs during embryogenesis involves a  

E-print Network

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

Parkhurst, Susan

397

Gene function in mouse embryogenesis: get set for gastrulation  

Microsoft Academic Search

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,

David A. F. Loebel; Patrick P. L. Tam

2007-01-01

398

Regional Specification during Embryogenesis in the Inarticulate Brachiopod Discinisca  

Microsoft Academic Search

The process of embryogenesis is described for the inarticulate brachiopodDiscinisca strigataof the family Discinidae. A fate map has been constructed for the early embryo. The animal half of the egg forms the dorsal ectoderm of the apical and mantle lobes. The vegetal half forms mesoderm and endoderm and is the site of gastrulation; it also forms the ectoderm of the

Gary Freeman

1999-01-01

399

Transformation of white spruce ( Picea glauca) somatic embryos by microprojectile bombardment  

Microsoft Academic Search

Cotyledonary somatic embryos of white spruce [Picea glauca (Moench) Voss] were subjected to microprojectile bombardment with a gene construct containing a gus::nptll fusion gene. Somatic embryos were used to re-induce the embryogenic tissue after bombardments. Histochemical assay using X-gluc as a substrate showed that all the embryos (100%) were GUS positive 48 h after bombardment. However, only thirteen out of

V. R. Bommineni; R. N. Chibbar; R. S. S. Datla; E. W. T. Tsang

1993-01-01

400

Genome-wide analysis reveals divergent patterns of gene expression during zygotic and somatic embryo maturation of Theobroma cacao L., the chocolate tree  

PubMed Central

Background Theobroma cacao L. is a tropical fruit tree, the seeds of which are used to create chocolate. In vitro somatic embryogenesis (SE) of cacao is a propagation system useful for rapid mass-multiplication to accelerate breeding programs and to provide plants directly to farmers. Two major limitations of cacao SE remain: the efficiency of embryo production is highly genotype dependent and the lack of full cotyledon development results in low embryo to plant conversion rates. With the goal to better understand SE development and to improve the efficiency of SE conversion we examined gene expression differences between zygotic and somatic embryos using a whole genome microarray. Results The expression of 28,752 genes was determined at 4 developmental time points during zygotic embryogenesis (ZE) and 2 time points during cacao somatic embryogenesis (SE). Within the ZE time course, 10,288 differentially expressed genes were enriched for functions related to responses to abiotic and biotic stimulus, metabolic and cellular processes. A comparison ZE and SE expression profiles identified 10,175 differentially expressed genes. Many TF genes, putatively involved in ethylene metabolism and response, were more strongly expressed in SEs as compared to ZEs. Expression levels of genes involved in fatty acid metabolism, flavonoid biosynthesis and seed storage protein genes were also differentially expressed in the two types of embryos. Conclusions Large numbers of genes were differentially regulated during various stages of both ZE and SE development in cacao. The relatively higher expression of ethylene and flavonoid related genes during SE suggests that the developing tissues may be experiencing high levels of stress during SE maturation caused by the in vitro environment. The expression of genes involved in the synthesis of auxin, polyunsaturated fatty acids and secondary metabolites was higher in SEs relative to ZEs despite lack of lipid and metabolite accumulation. These differences in gene transcript levels associated with critical processes during seed development are consistent with the fact that somatic embryos do not fully develop the large storage cotyledons found in zygotic embryos. These results provide insight towards design of improved protocols for cacao somatic embryogenesis. PMID:25030026

2014-01-01

401

Can Somatic Stem Cells Regenerate Myocardial Tissue?  

Microsoft Academic Search

Somatic stem cells can be obtained from various sources and their differentiation potential is not restricted only to the\\u000a differentiated cell phenotypes of the source tissue. Therefore, somatic stem cells offer a great promise for cell replacement\\u000a therapy in diseased hearts. Yet, much confusion has been created concerning the use of somatic stem cells. Different methods\\u000a have been used to

Marie Jose Goumans; Anke Smits; Piet van Vliet; Simone Post; Rutger J. Hassink; Pieter Stella; Pieter A. Doevendans

402

Somatization symptoms in pediatric abdominal pain patients: Relation to chronicity of abdominal pain and parent somatization  

Microsoft Academic Search

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

Lynn S. Walker; Judy Garber; John W. Greene

1991-01-01

403

Instant neurons: directed somatic cell reprogramming models of central nervous system disorders.  

PubMed

Nuclear transplantation, cell fusion, and induced pluripotent stem cell studies have revealed a surprising degree of plasticity in mature mammalian cell fates. Somatic cell reprogramming also has been achieved more recently by the directed conversion of nonneuronal somatic cells, such as skin fibroblasts, to neuronal phenotypes. This approach appears particularly applicable to the in vitro modeling of human neurologic disorders. Central nervous system neurons are otherwise difficult to obtain from patients with neurologic disorders; however, nonhuman models may not reflect patient pathology. Somatic cell reprogramming may afford models of nonfamilial "sporadic" neurologic disorders, which are likely caused by multiple interacting genetic and nongenetic factors. Directed somatic cell reprogramming, which does not pass through typical in vivo developmental stages, toward many mature neuronal phenotypes has now been described. This article reviews the field and discusses the potential utilities of such models, such as for the development of personalized medicine strategies. PMID:24525100

Qiang, Liang; Inoue, Keiichi; Abeliovich, Asa

2014-06-15

404

Axes, planes and tubes, or the geometry of embryogenesis  

Microsoft Academic Search

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

Sabine Brauckmann

2011-01-01

405

Expression of the Tgf?2 gene during chick embryogenesis.  

PubMed

We performed a comprehensive analysis of the expression of transforming growth factor (TGF) ?2 during chick embryogenesis from stage 6 to 30 (Hamburger and Hamilton, J Morphol 1951;88:49-92) using in situ hybridization. During cardiogenesis, Tgf?2 was expressed in the endothelial/mesenchymal cells of the valvulo-septal endocardial cushion tissue and in the epicardium until the end of embryogenesis. During the formation of major arteries, Tgf?2 was localized in smooth muscle progenitors but not in the vascular endothelium. During limb development, Tgf?2 was expressed in the mesenchymal cells in the presumptive limb regions at stage 16, and thereafter it was localized in the skeletal muscle progenitors. In addition, strong Tgf?2 expression was seen in the mesenchymal cells in the pharyngeal arches. Tgf?2 mRNA was also detected in other mesoderm-derived tissues, such as the developing bone and pleura. During ectoderm development, Tgf?2 was expressed in the floor plate of the neural tube, lens, optic nerve, and otic vesicle. In addition, Tgf?2 was expressed in the developing gut epithelium. Our results suggest that TGF?2 plays an important role not only in epithelial-mesenchymal interactions but also in cell differentiation and migration and cell death during chick embryogenesis. We also found that chick and mouse Tgf?2 RNA show very similar patterns of expression during embryogenesis. Chick embryos can serve as a useful model to increase our understanding in the roles of TGF?2 in cell-cell interactions, cell differentiation, and proliferation during organogenesis. PMID:22190426

Yamagishi, Toshiyuki; Ando, Katsumi; Nakamura, Hiroaki; Nakajima, Yuji

2012-02-01

406

Integrative analysis of a cancer somatic mutome  

Microsoft Academic Search

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

2007-01-01

407

Genomic profiling to improve embryogenesis in the pig.  

PubMed

Over the past decade the technology to characterize transcription during embryogenesis has progressed from estimating a single transcript to a reliable description of the entire transcriptome. Northern blots were followed by sequencing ESTs, quantitative real time PCR, cDNA arrays, custom oligo arrays, and more recently, deep sequencing. The amount of information that can be generated is overwhelming. The challenge now is how to glean information from these vast data sets that can be used to understand development and to improve methods for creating and culturing embryos in vitro, and for reducing reproductive loss. The use of ESTs permitted the identification of SPP1 as an oviductal component that could reduce polyspermy. Microarrays identified LDL and NMDA as components to replace BSA in embryo culture media. Deep sequencing implicated arginine, glycine, and folate as components that should be adjusted in our current culture system, and identified a characteristic of embryo metabolism that is similar to cancer and stem cells. Not only will these characterizations aid in improving in vitro production of embryos, but will also be useful for identifying, or creating conditions for donor cells that will be more likely to result in normal development of cloned embryos. The easily found targets have been identified, and now more sophisticated methods are being employed to advance our understanding of embryogenesis. Here the technology to study the global transcriptome is reviewed followed by specific examples of how the technology has been used to understand and improve porcine embryogenesis both in vitro and in vivo. PMID:24878355

Prather, Randall S; Redel, Bethany K; Whitworth, Kristin M; Zhao, Ming-Tao

2014-09-01

408

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

PubMed

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

Lebold, Katie M; Traber, Maret G

2014-01-01

409

Somatic Mosaicism in the Human Genome  

PubMed Central

Somatic mosaicism refers to the occurrence of two genetically distinct populations of cells within an individual, derived from a postzygotic mutation. In contrast to inherited mutations, somatic mosaic mutations may affect only a portion of the body and are not transmitted to progeny. These mutations affect varying genomic sizes ranging from single nucleotides to entire chromosomes and have been implicated in disease, most prominently cancer. The phenotypic consequences of somatic mosaicism are dependent upon many factors including the developmental time at which the mutation occurs, the areas of the body that are affected, and the pathophysiological effect(s) of the mutation. The advent of second-generation sequencing technologies has augmented existing array-based and cytogenetic approaches for the identification of somatic mutations. We outline the strengths and weaknesses of these techniques and highlight recent insights into the role of somatic mosaicism in causing cancer, neurodegenerative, monogenic, and complex disease. PMID:25513881

Freed, Donald; Stevens, Eric L.; Pevsner, Jonathan

2014-01-01

410

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

PubMed

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

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

2014-11-01

411

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

PubMed Central

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

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

2014-01-01

412

Somatic embryogenesis, regeneration and in vitro production of glycyrrhizic acid from root cultures of Taverniera cuneifolia (Roth) Arn  

Microsoft Academic Search

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

Vitthal Awad; Rohit Shirke; Sourav Mukherjee; Suresh Khadke; Pankaj Pawar; Nilambika Meti; Abhay Harsulkar

413

Characterization of LEAFY COTYLEDON1LIKE gene in Helianthus annuus and its relationship with zygotic and somatic embryogenesis  

Microsoft Academic Search

The Helianthus annuus LEAFY COTYLEDON1-LIKE (HaL1L) gene encodes a heme-activated protein 3 subunit of the CCAAT box-binding factor. The phylogenetic analysis indicates that HaL1L is closely related to LEAFY COTYLEDON1 (LEC1)-type of Arabidopsis thaliana. In particular, the peptide results homologous to the LEC1-LIKE gene of A. thaliana, with which it shares a high amino acid sequence identity (56%). HaL1L transcripts

Marco Fambrini; Chiara Durante; Giuliano Cionini; Chiara Geri; Lucia Giorgetti; Vania Michelotti; Mariangela Salvini; Claudio Pugliesi

2006-01-01

414

Rapid and efficient transformation of diploid Medicago truncatula and Medicago sativa ssp. falcata lines improved in somatic embryogenesis  

Microsoft Academic Search

We describe a simple and efficient protocol for regeneration-transformation of two diploid Medicago lines: the annual M. truncatula R108-1(c3) and the perennial M. sativa ssp. falcata (L.) Arcangeli PI.564263 selected previously as highly embryogenic genotypes. Here, embryo regeneration of R108-1 to complete\\u000a plants was further improved by three successive in vitro regeneration cycles resulting in the line R108-1(c3). Agrobacterium tumefaciens-mediated

T. H. Trinh; P. Ratet; E. Kondorosi; P. Durand; K. Kamaté; P. Bauer; A. Kondorosi

1998-01-01

415

Genotype and plant growth regulator-dependent response of somatic embryogenesis from G entiana spp. leaf explants  

Microsoft Academic Search

Gentiana kurroo (Royle), Gentiana cruciata (L.), Gentiana tibetica (King. ex Hook. f.), Gentiana lutea (L.), and Gentiana pannonica (Scop.) leaves derived from axenic shoot culture were used as explants. For culture initiation, leaves from the first and\\u000a second whorls from the apical dome were dissected and cultured on Murashige and Skoog (MS) basal medium supplemented with\\u000a three different auxins: 2,4-dichlorophenoxyacetic

Agnieszka Fiuk; Jan J. Rybczy?ski

2008-01-01

416

In vitro regeneration of chickpea (Cicer arietinum L.): Stimulation of direct organogenesis and somatic embryogenesis by thidiazuron  

Microsoft Academic Search

In vitro regeneration in chickpea (Cicer arietinum L.) was achieved by direct culture of mature seeds on Murashige and Skoog (MS) medium supplemented with either N-phenyl-N'(-1,2,3-thidiazol-5-yl) urea (thidiazuron, TDZ) or N6-benzylaminopurine (BAP). Multiple shoots formed de novo without an intermediary callus phase at the cotyledonary notch region of the seedlings within 2 to 3 weeks of culture initiation. TDZ was

B. N. S. Murthy; Jerrin Victor; Rana P. Singh; R. A. Fletcher; Praveen K. Saxena

1996-01-01

417

Plant regeneration through somatic embryogenesis in root-derived callus of ginseng ( Panax ginseng C. A. Meyer)  

Microsoft Academic Search

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.

W. C. Chang; Y. I. Hsing

1980-01-01

418

In vitro regeneration of Echinacea purpurea L.: Direct somatic embryogenesis and indirect shoot organogenesis in petiole culture  

Microsoft Academic Search

Summary  An in vitro propagation system was developed for Echinacea purpurea L. (purple coneflower), a medicinal plant commonly used in the treatment of colds, flu and related ailments. Echinacea seeds were found to be contaminated with systemic fungi and therefore an optimized minimal concentration of Plant Preservation\\u000a Mixture (PPM) was incorporated in the seed germination medium to recover sterile seedlings. Regeneration

Kristen L. Choffe; Jerrin M. R. Victor; Susan J. Murch; Praveen K. Saxena

2000-01-01

419

Thin cell suspension layer as a new methodology for somatic embryogenesis in Agave tequilana Weber cultivar azul  

Microsoft Academic Search

Commercial micropropagation of plants is enhanced with the use of liquid media cultures; however the presence of hyperhydricity is commonly observed in cultures of the succulent plant Agave tequilana Weber cultivar azul, this phenomenon persists even with the use of temporary immersion systems (TIS). Thin cell suspension layer technology is proposed to solve this problem. This technology fuses the advantages

Fernando Santacruz-Ruvalcaba; Liberato Portillo

2009-01-01

420

Effect of in vitro shoot multiplication and somatic embryogenesis on 5-methylcytosine content in DNA of Myrtus communis L  

Microsoft Academic Search

Reversed-phase HPLC analysis of 2'-deoxynucleosides was performedto study the amount of 5-methylcytosine in genornic DNA of Myrtuscommunis L. About 11% cytosines were found to be methylated inDNA of field growing shoots. This amount showed no variation after theestablishment of shoots in vitro or their subsequentrooting and acclimatisation to ex vitro conditions.Therefore, adult elite plants can be micropropagated and transferred to

R. Parra; M. T. Pastor; E. Pérez-Payá; J. B. Amo-Marco

2001-01-01

421

Embryogenesis and plant regeneration from isolated microspores of Brassica rapa L. ssp. Oleifera  

Microsoft Academic Search

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

Laurie Burnett; Stephen Yarrow; Bin Huang

1992-01-01

422

Somatic development in cleidocranial dysplasia.  

PubMed

As part of a more comprehensive investigation of general and craniofacial development in cleidocranial dysplasia (CCD), the present study describes general somatic development and analyzes longitudinal growth of 17 patients (seven males, ten females, aged 5-46 years) with CCD. Eleven were followed longitudinally. Data included family history, anthropometric measurements, and radiographs of the right hand and forearm. Height and radius length were significantly decreased, being most pronounced in females. The longitudinal growth data showed growth retardation and slightly retarded skeletal maturity throughout childhood. Metacarpophalangeal pattern profile analysis demonstrated great variation in bone lengths, presumably resulting from extra epiphyses in the 2nd and 5th metacarpals and from multiple cone-shaped epiphyses. Findings of the present study support the view that CCD is a generalized skeletal dysplasia. PMID:2301472

Jensen, B L

1990-01-01

423

Low-level mesodermal somatic mutation mosaicism: late-onset craniofacial and cervical spinal hyperostoses.  

PubMed

Craniofacial and cervical spinal hyperostoses are rarely seen in the absence of other abnormalities. Only seven patients with isolated cranial hyperostoses have been reported, and only a single patient with both calvarial and cervical vertebral hyperostoses. We report on an adult with late-onset right-sided asymmetrical hyperostoses of the cranium, mandible, and cervical vertebrae in the absence of an AKT1 mutation. At presentation, the patient displayed neither generalized overgrowth nor dysregulated adipose tissue. Standard polymerase chain reaction and Sanger sequencing of DNA extracted from formalin-fixed paraffin-embedded frontal bone and mandibular angular bone was negative for an AKT1 mutation. Though the patient's clinical manifestations did not fulfill the consensus diagnostic criteria of Proteus syndrome, the mosaic distribution of lesions, the sporadic occurrence, and the patient's progressive course were consistent with a somatic mosaicism similar to that syndrome. Hence, the patient's phenotype may have been caused by a very late mesodermal somatic mutation during embryogenesis. PMID:24357582

Kubota, Yoshitaka; Mitsukawa, Nobuyuki; Uchida, Michiko; Uchida, Yuuki; Akita, Shinsuke; Hasegawa, Masakazu; Satoh, Kaneshige

2014-03-01

424

Hypothesis: Somatic Mosaicism and Parkinson Disease  

PubMed Central

Mutations causing genetic disorders can occur during mitotic cell division after fertilization, which is called somatic mutations. This leads to somatic mosaicism, where two or more genetically distinct cells are present in one individual. Somatic mutations are the most well studied in cancer where it plays an important role and also have been associated with some neurodegenerative disorders. The study of somatic mosaicism in Parkinson disease (PD) is only in its infancy, and a case with somatic mutation has not yet been described. However, we can speculate that a somatic mutation affecting cells in the central nervous system including substantia nigra dopaminergic neurons could lead to the development of PD through the same pathomechanisms of genetic PD even in the absence of a germ-line mutation. Theoretically, a number of genes could be candidates for genetic analysis for the presence of somatic mosaicism. Among them, SNCA and PARK2 could be the best candidates to analyze. Because analyzing brain tissues in living patients is impossible, alternative tissues could be used to indicate the genetic status of the brain. Performance of the technology is another factor to consider when analyzing the tissues. PMID:25548528

Kim, Han-Joon

2014-01-01

425

Hypothesis: somatic mosaicism and Parkinson disease.  

PubMed

Mutations causing genetic disorders can occur during mitotic cell division after fertilization, which is called somatic mutations. This leads to somatic mosaicism, where two or more genetically distinct cells are present in one individual. Somatic mutations are the most well studied in cancer where it plays an important role and also have been associated with some neurodegenerative disorders. The study of somatic mosaicism in Parkinson disease (PD) is only in its infancy, and a case with somatic mutation has not yet been described. However, we can speculate that a somatic mutation affecting cells in the central nervous system including substantia nigra dopaminergic neurons could lead to the development of PD through the same pathomechanisms of genetic PD even in the absence of a germ-line mutation. Theoretically, a number of genes could be candidates for genetic analysis for the presence of somatic mosaicism. Among them, SNCA and PARK2 could be the best candidates to analyze. Because analyzing brain tissues in living patients is impossible, alternative tissues could be used to indicate the genetic status of the brain. Performance of the technology is another factor to consider when analyzing the tissues. PMID:25548528

Kim, Han-Joon; Jeon, Beom S

2014-12-01

426

Fusion as the result of sperm-somatic cell interaction.  

PubMed

The research has been designed to investigate whether acrosome-reacted spermatozoa can fuse with somatic cells and to check whether this event may involve the molecular machinery implicated in the sperm-egg fusion. Boar spermatozoa were capacitated in vitro and then treated with A23187 to induce acrosome reaction and activate their fusogenic potential. Reacted spermatozoa, loaded with the membrane-permeant fluorescent dye calcein AM, were incubated with plated granulosa cells or cells derived from stable cell lines: CRFK, VERO, and ESK4. The fusion between spermatozoa and somatic cells was revealed by the diffusion of the fluorescent dye from the sperm to the cell as membrane fusion and cytoplasmic continuity between the two cells were established. The involvement of integrin alpha6 and tetraspanin CD9 in the process of fusion was assessed by carrying out the experiment in the presence of antibodies against these molecules. Moreover, the incidence of fusion displayed by the different cell types used was analyzed in relation to their content in the above molecules assessed by western blot and immunostaining. The role of CD9 was additionally investigated by using CD9-negative cells. The data presented demonstrate that boar spermatozoa can fuse with different somatic cell types derived from different species and the process requires the combined presence of both integrin and tetraspanin molecules on the cell plasma membrane. PMID:19584174

Mattioli, M; Gloria, A; Mauro, A; Gioia, L; Barboni, B

2009-10-01

427

E3 ubiquitin ligases promote progression of differentiation during C. elegans embryogenesis.  

PubMed

Regulated choice between cell fate maintenance and differentiation provides decision points in development to progress toward more restricted cell fates or to maintain the current one. Caenorhabditis elegans embryogenesis follows an invariant cell lineage where cell fate is generally more restricted upon each cell division. EMS is a progenitor cell in the four-cell embryo that gives rise to the endomesoderm. We recently found that when ubiquitin-mediated protein degradation is compromised, the anterior daughter of EMS, namely MS, reiterates the EMS fate. This observation demonstrates an essential function of ubiquitin-mediated protein degradation in driving the progression of EMS-to-MS differentiation. Here we report a genome-wide screen of the ubiquitin pathway and extensive lineage analyses. The results suggest a broad role of E3 ligases in driving differentiation progression. First, we identified three substrate-binding proteins for two Cullin-RING ubiquitin ligase (CRL) E3 complexes that promote the progression from the EMS fate to MS, namely LIN-23/?-TrCP and FBXB-3 for the CRL1/SCF complex and ZYG-11/ZYG-11B for the CRL2 complex. Genetic analyses suggest these E3 ligases function through a multifunctional protein OMA-1 and the endomesoderm lineage specifier SKN-1 to drive differentiation. Second, we found that depletion of components of the CRL1/SCF complex induces fate reiteration in all major founder cell lineages. These data suggest that regulated choice between self-renewal and differentiation is widespread during C. elegans embryogenesis as in organisms with regulative development, and ubiquitin-mediated protein degradation drives the choice towards differentiation. Finally, bioinformatic analysis of time series gene expression data showed that expression of E3 genes is transiently enriched during time windows of developmental stage transitions. Transcription factors show similar enrichment, but not other classes of regulatory genes. Based on these findings we propose that ubiquitin-mediated protein degradation, like many transcription factors, function broadly as regulators driving developmental progression during embryogenesis in C. elegans. PMID:25523393

Du, Zhuo; He, Fei; Yu, Zidong; Bowerman, Bruce; Bao, Zhirong

2015-02-15

428

The use of centrifugation to study early Drosophila embryogenesis  

NASA Technical Reports Server (NTRS)

By the end of 10th nuclear cycle, the somatic nuclei of the Drosophila embryo have migrated to the periphery of the egg. Centrifugation of embryos did not result in the displacement of these nuclei, since cytoskeletal elements anchor them to the cortex. But, mild centrifugal forces displace the centrally located, nascent yolk nuclei. If this increased sensitivity to hypergravity occurs before the beginning of nuclear differentiation during cycle 8, when the nascent yolk and somatic nuclei physically separate, then it would mark the earliest functional difference between these two lineages.

Abbott, M. K.; Spooner, B. S. (Principal Investigator)

1993-01-01

429

In vivo imaging of zebrafish embryogenesis  

PubMed Central

The zebrafish Danio rerio has emerged as a powerful vertebrate model system that lends itself particularly well to quantitative investigations with live imaging approaches, owing to its exceptionally high optical clarity in embryonic and larval stages. Recent advances in light microscopy technology enable comprehensive analyses of cellular dynamics during zebrafish embryonic development, systematic mapping of gene expression dynamics, quantitative reconstruction of mutant phenotypes and the system-level biophysical study of morphogenesis. Despite these technical breakthroughs, it remains challenging to design and implement experiments for in vivo long-term imaging at high spatio-temporal resolution. This article discusses the fundamental challenges in zebrafish long-term live imaging, provides experimental protocols and highlights key prop1erties and capabilities of advanced fluorescence microscopes. The article focuses in particular on experimental assays based on light sheet-based fluorescence microscopy, an emerging imaging technology that achieves exceptionally high imaging speeds and excellent signal-to-noise ratios, while minimizing light-induced damage to the specimen. This unique combination of capabilities makes light sheet microscopy an indispensable tool for the in vivo long-term imaging of large developing organisms. PMID:23523701

Keller, Philipp J.

2013-01-01

430

Regeneration of Plants by Embryogenesis with Callus Cultures of Carum carvi L.  

PubMed

This report describes the regeneration of plants from callus cultures of caraway, Carum carvi L. Callus of hypocotyl origin was maintained on medium containing Murashige and Skoog salts with Nitsch and Nitsch vitamins in the presence of 0.3 mg · l(-1) 2,4-D. Formation of somatic embryos was induced with suspension cultures once 2,4-D had been removed. Embryos developed into plantlets when subcultured on solid medium supplemented with 0.5 mg · l(-1) IBA and 10.0 mg · l(-1) adenine sulphate. Regenerated plantlets were transferred to soil. PMID:23194576

Furmanowa, M; Oledzka, H; Sowi?ska, D

1984-07-01

431

Disruption of Circulation by Ethanol Promotes Fetal Alcohol Spectrum Disorder (FASD) in Medaka (Oryzias latipes) Embryogenesis  

PubMed Central

Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features of fetal alcohol spectrum disorder (FASD) observed in human. The present experiment was designed to show that the disruption in circulation by ethanol during embryogenesis is a potential cause of FASD. Fertilized eggs were exposed to ethanol (0, 100 and/or 400 mM) for 24 or 48 h at various developmental stages (Iwamatsu stages 4–30) and were analyzed at 6 day post fertilization (dpf). It was observed that controls and the embryos exposed to 100 mM ethanol were in circulating state; however, a significant number of embryos of stages 4–24 exposed to 400 mM ethanol had disrupted circulation. Compared to controls, protein and RNA contents were significantly reduced in non-circulating embryos. Lipid peroxidation (LPO) analysis was made at 3, 6, 24, 48, 96 and 144 hour post fertilization (hpf). LPO was increased with the advancement of morphogenesis; however, ethanol or the circulation status had no effect. We further analyzed alcohol dehydrogenase (Adh 5 and adh8) and aldehyde dehydrogenase (Aldh9A and Aldh1A2) enzyme mRNAs in the embryos exposed to 400 mM ethanol for 24h. A developmental stage specific reduction in these enzyme mRNAs by ethanol was observed. We conclude that ethanol-induced disruption in circulation during embryogenesis is a potential cause of the development of FASD features in medaka. PMID:18621148

Hu, Yuhui; Khan, Ikhlas A.; Dasmahapatra, Asok K.

2008-01-01

432

Epithelial self-organization in fruit fly embryogenesis  

NASA Astrophysics Data System (ADS)

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.

Hutson, M. Shane

2010-03-01

433

Somatization: a borderland between medicine and psychiatry.  

PubMed Central

Somatization is the tendency to experience and communicate psychologic distress in the form of somatic symptoms that the patient misinterprets as signifying serious physical illness. Patients with persistent somatization relentlessly seek medical diagnosis and treatment despite repeated reassurance that physical illness is either absent or insufficient to account for their symptoms and disability. Such abnormal illness behaviour leads to overuse of health care facilities and contributes to the high cost of health care. Somatization may occur transiently in response to stressful life events or it may be persistent and result in chronic partial or total disability. Diagnostic and therapeutic guidelines that may help physicians identify and manage such patients more effectively are discussed. PMID:3489512

Lipowski, Z J

1986-01-01

434

Lipid Rafts: Keys to Sperm Maturation, Fertilization, and Early Embryogenesis  

PubMed Central

Cell membranes are composed of many different lipids and protein receptors, which are important for regulating intracellular functions and cell signaling. To orchestrate these activities, the cell membrane is compartmentalized into microdomains that are stably or transiently formed. These compartments are called “lipid rafts”. In gamete cells that lack gene transcription, distribution of lipids and proteins on these lipid rafts is focused during changes in their structure and functions such as starting flagella movement and membrane fusion. In this paper, we describe the role of lipid rafts in gamete maturation, fertilization, and early embryogenesis. PMID:21490798

Kawano, Natsuko; Yoshida, Kaoru; Miyado, Kenji; Yoshida, Manabu

2011-01-01

435

From Traumatic Attachment to Somatization Disorder  

Microsoft Academic Search

Objective: This paper emphasizes attachment trauma as an important etiological factor in somatization disorder and psychoanalytic psychotherapy as an effective treatment.Method: Weekly psychotherapy with an 18 year old with somatization disorder, using the Conversational Model, is described.Conclusion: Early cumulative trauma has far-reaching health consequences. Brief psychotherapy produces symptom relief, and long-term analytic therapy is necessary for sustained improvement.

Joan Haliburn

2011-01-01

436

High-Dose Irradiation Induces Cell Cycle Arrest, Apoptosis, and Developmental Defects during Drosophila Oogenesis  

PubMed Central

Ionizing radiation (IR) treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs) generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis. PMID:24551207

Shim, Hee Jin; Lee, Eun-Mi; Nguyen, Long Duy; Shim, Jaekyung; Song, Young-Han

2014-01-01

437

Exome sequencing identifies recurrent somatic MAP2K1 and MAP2K2 mutations in melanoma  

Microsoft Academic Search

We performed exome sequencing to detect somatic mutations in protein-coding regions in seven melanoma cell lines and donor-matched germline cells. All melanoma samples had high numbers of somatic mutations, which showed the hallmark of UV-induced DNA repair. Such a hallmark was absent in tumor sample–specific mutations in two metastases derived from the same individual. Two melanomas with non-canonical BRAF mutations

Christian Iseli; Armand Valsesia; Daniel Robyr; Corinne Gehrig; Keith Harshman; Michel Guipponi; Olesya Bukach; Vincent Zoete; Olivier Michielin; Katja Muehlethaler; Daniel Speiser; Jacques S Beckmann; Ioannis Xenarios; Thanos D Halazonetis; C Victor Jongeneel; Brian J Stevenson; Sergey I Nikolaev; Donata Rimoldi; Stylianos E Antonarakis

2011-01-01

438

Transcriptomic study of the red palm weevil Rhynchophorus ferrugineus embryogenesis.  

PubMed

The red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae), is an invasive, concealed and destructive tissue borer, and it becomes a lethal pest of the palm family of plants and has been reported to attack 20 palm species around the globe. Here we report a systematic transcriptomic study on embryogenesis of RPW, where we analyze the transcriptomes across five developmental stages of RPW embryogenesis, involving four embryonic stages (E1, E2, E3 and E4) and one larval stage (L1). Using the RNA-seq and next-generation platforms, we generated 80 to 91 million reads for each library and assemble 22 532 genes that are expressed at different embryonic stages. Among the total transcripts from the five embryonic development stages, we found that 30.45 % are differentially expressed, 10.10?% show stage-specificity and even a larger fraction, 62.88 %, exhibit constitutive expression in all the stages. We also analyzes the expression dynamics of several conserved signaling pathways (such as Hedgehog, JAK-STAT, Notch, TGF-?, Ras/MAPK and Wnt), as well as key developmental genes, including those related to apoptosis, axis formation, Hox complex, neurogenesis and segmentation. The datasets provide an essential resource for gene annotation and RPW functional genomics, including studies by using tools and concepts from multiple disciplines, such as development, physiology, biochemistry, molecular biology and genetics. PMID:24347559

Yin, An; Pan, Linlin; Zhang, Xiaowei; Wang, Lei; Yin, Yuxin; Jia, Shangang; Liu, Wanfei; Xin, Chengqi; Liu, Kan; Yu, Xiaoguang; Sun, Gaoyuan; Al-Hudaib, Khalid; Hu, Songnian; Al-Mssallem, Ibrahim S; Yu, Jun

2015-02-01

439

Anopheles albitarsis embryogenesis: morphological identification of major events.  

PubMed

Anopheles albitarsis embryogenesis was analyzed through confocal microscopy of clarified eggs. Using Drosophila melanogaster as reference system, the major morphogenetic events (blastoderm, gastrulation, germ band extension, germ band retraction, dorsal closure) were identified. The kinetics of early events is proportionally similar in both systems, but late movements (from germ band retraction on) progress slower in An. albitarsis. Major differences in An. albitarsis related to D. melanogaster were: (1) pole cells do not protrude from the blastoderm; (2) the mosquito embryo undergoes a 180 degrees rotation movement, along its longitudinal axis; (3) the head remains individualized throughout embryogenesis; (4) extraembryonary membranes surround the whole embryo. A novel kind of malaria control is under development and is based on the use of genetically modified mosquitoes. Phenotypic analysis of the embryonic development of mutants will be imposed as part of the evaluation of effectiveness and risk of employment of this strategy in the field. In order to accomplish this, knowledge of the wild type embryo is a prerequisite. Morphological studies will also serve as basis for subsequent development biology approaches. PMID:12118297

Monnerat, Adelaide Tardin; Machado, Marcelo Pelajo; Vale, Bruno Silva; Soares, Maurilio José; Lima, José Bento Pereira; Lenzi, Henrique Leonel; Valle, Denise

2002-06-01

440

Effect of repetitive acute cold exposures during the last phase of broiler embryogenesis on cold resistance through the life span.  

PubMed

The time just before hatch is critical, because the embryo shifts toward internal and external pipping. This study aimed to determine the beneficial effect of repeated acute reductions of the incubation temperature during the last phase of broiler embryogenesis on posthatch cold tolerance and on the development of ascites syndrome. Fertile eggs were incubated at 37.8 degrees C and 56% RH. At 18 and 19 d of incubation, 3 treatments were conducted, comprising 2 or 3 exposures to 15 degrees C for 30 or 60 min each. During these cold exposures, egg temperature was measured by infrared thermography to determine sensible heat loss from the eggs. At hatch, BW and body temperature were measured. At 3 and 14 d of age, chicks were challenged by cold exposure to 10 degrees C for 3 h. From 14 d of age onward, three-quarters of the chicks were raised under ascites-inducing conditions (AIC) and the others were raised under regular conditions. The sensible heat loss from the eggs was 512 +/- 66 cal and 718 +/- 126 cal for 30 and 60 min of cold exposure, respectively. No effect of treatment on hatchability was observed, but body temperature and BW were greater to significantly greater in the treated chicks. Cold challenges at 3 and 14 d of age revealed a relative thermoregulatory advantage of embryos exposed to cold for 60 min. Under AIC, fewer treated chickens than controls developed ascites. At 38 d of age, BW and relative breast muscle weight were numerically to significantly greater in the treated chicks than in the control chicks when both were raised under regular conditions, whereas no differences were observed among the chicks raised under AIC. Repeated brief acute cold exposures during the last phase of embryogenesis appeared to improve the ability of growing broilers to withstand low ambient temperatures during their life span. Moreover, chickens treated during embryogenesis improved their performance under regular growth conditions. PMID:19211536

Shinder, D; Rusal, M; Giloh, M; Yahav, S

2009-03-01

441

Somatic Genome Variations in Health and Disease  

PubMed Central

It is hard to imagine that all the cells of the human organism (about 1014) share identical genome. Moreover, the number of mitoses (about 1016) required for the organism’s development and maturation during ontogeny suggests that at least a proportion of them could be abnormal leading, thereby, to large-scale genomic alterations in somatic cells. Experimental data do demonstrate such genomic variations to exist and to be involved in human development and interindividual genetic variability in health and disease. However, since current genomic technologies are mainly based on methods, which analyze genomes from a large pool of cells, intercellular or somatic genome variations are significantly less appreciated in modern bioscience. Here, a review of somatic genome variations occurring at all levels of genome organization (i.e. DNA sequence, subchromosomal and chromosomal) in health and disease is presented. Looking through the available literature, it was possible to show that the somatic cell genome is extremely variable. Additionally, being mainly associated with chromosome or genome instability (most commonly manifesting as aneuploidy), somatic genome variations are involved in pathogenesis of numerous human diseases. The latter mainly concerns diseases of the brain (i.e. autism, schizophrenia, Alzheimer’s disease) and immune system (autoimmune diseases), chromosomal and some monogenic syndromes, cancers, infertility and prenatal mortality. Taking into account data on somatic genome variations and chromosome instability, it becomes possible to show that related processes can underlie non-malignant pathology such as (neuro)degeneration or other local tissue dysfunctions. Together, we suggest that detection and characterization of somatic genome behavior and variations can provide new opportunities for human genome research and genetics. PMID:21358982

Iourov, I.Y.; Vorsanova, S.G.; Yurov, Y.B.

2010-01-01

442

Formulation of nutrient medium for in vitro somatic embryo induction in Plantago ovata forsk.  

PubMed

A nutrient medium has been formulated by altering the macro- and micro-elemental concentration in the culture medium for in vitro somatic embryo induction of economically important medicinal plant Plantago ovata Forsk .A comparison was made between induced embryos with normal embryos (produced in Murashige and Skoog (MS) medium) to observe frequency of embryo induction and also to determine regeneration efficiency. In the present investigation, three different media have been formulated. Among them, FM3 (formulated media, treatment 3) was the most suitable for increasing the frequency of somatic embryo production and regeneration of P. ovata Forsk. Better result was obtained using formulated medium than with MS medium. PMID:20405339

Saha, Priyanka; Bandyopadhyay, Subhendu; Raychaudhuri, Sarmistha Sen

2011-05-01

443

A longitudinal study of somatic complaints in urban adolescents: the role of internalizing psychopathology and somatic anxiety.  

PubMed

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

Ruchkin, Vladislav; Schwab-Stone, Mary

2014-05-01

444

The expression and roles of parent-of-origin genes in early embryogenesis of angiosperms  

PubMed Central

Uniparental transcripts during embryogenesis may arise due to gamete delivery during fertilization or genomic imprinting. Such transcripts have been found in a number of plant species and appear critical for the early development of embryo or endosperm in seeds. Although the regulatory expression mechanism and function of these genes in embryogenesis require further elucidation, recent studies suggest stage-specific and highly dynamic features that might be essential for critical developmental events such as zygotic division and cell fate determination during embryogenesis. Here, we summarize the current work in this field and discuss future research directions. PMID:25566300

Luo, An; Shi, Ce; Zhang, Liyao; Sun, Meng-Xiang

2014-01-01

445

Cellular Mechanisms of Somatic Stem Cell Aging  

PubMed Central

Tissue homeostasis and regenerative capacity rely on rare populations of somatic stem cells endowed with the potential to self-renew and differentiate. During aging, many tissues show a decline in regenerative potential coupled with a loss of stem cell function. Cells including somatic stem cells have evolved a series of checks and balances to sense and repair cellular damage to maximize tissue function. However, during aging the mechanisms that protect normal cell function begin to fail. In this review, we will discuss how common cellular mechanisms that maintain tissue fidelity and organismal lifespan impact somatic stem cell function. We will highlight context-dependent changes and commonalities that define aging, by focusing on three age-sensitive stem cell compartments: blood, neural, and muscle. Understanding the interaction between extrinsic regulators and intrinsic effectors that operate within different stem cell compartments is likely to have important implications for identifying strategies to improve health span and treat age-related degenerative diseases. PMID:24439814

Jung, Yunjoon

2014-01-01

446

Mechanics in embryogenesis and embryonics: prime mover or epiphenomenon?  

PubMed

Mechanics is shown to be an important, perhaps central component to the differentiation and development of embryos. Mechanics of the nucleus may also be involved in determining which genes are expressed in a given cell. There are two major approaches at present to the mechanics of differentiation in embryos: morphomechanics and differentiation waves. These are compared in detail, to provide a starting point for future experimental work to bring them into one conceptual framework. This may rationalize the present cookbookery of stem cell production by placing it in the context of differentiation waves and the differentiation code. Embryonics, the realization of concepts from embryology in computer hardware and software, might be considerably enhanced by incorporating mechanical concepts of embryogenesis. Segmented robots, modular robotics, cellular microrobotics, flexible electronics, wearable computers, diatom nanotechnology and waves in active media point to a synthesis that we could call embryonic robotics. PMID:16479492

Gordon, Richard

2006-01-01

447

A Reverse Genetic Approach to Test Functional Redundancy During Embryogenesis  

PubMed Central

Gene function during embryogenesis is typically defined by loss-of-function experiments, for example by targeted mutagenesis (knockout) in the mouse. In the zebrafish model, effective reverse genetic techniques have been developed using microinjection of gene-specific antisense morpholinos. Morpholinos target an mRNA through specific base-pairing and block gene function transiently by inhibiting translation or splicing for several days during embryogenesis (knockdown). However, in vertebrates such as mouse or zebrafish, some gene functions can be obscured by these approaches due to the presence of another gene that compensates for the loss. This is especially true for gene families containing sister genes that are co-expressed in the same developing tissues. In zebrafish, functional compensation can be tested in a relatively high-throughput manner, by co-injection of morpholinos that target knockdown of both genes simultaneously. Likewise, using morpholinos, a genetic interaction between any two genes can be demonstrated by knockdown of both genes together at sub-threshold levels. For example, morpholinos can be titrated such that neither individual knockdown generates a phenotype. If, under these conditions, co-injection of both morpholinos causes a phenotype, a genetic interaction is shown. Here we demonstrate how to show functional redundancy in the context of two related GATA transcription factors. GATA factors are essential for specification of cardiac progenitors, but this is revealed only by the loss of both Gata5 and Gata6. We show how to carry out microinjection experiments, validate the morpholinos, and evaluate the compensated phenotype for cardiogenesis. PMID:20736915

Rikin, Amir; Rosenfeld, Gabriel E.; McCartin, Kellie; Evans, Todd

2010-01-01

448

Dynamic Nucleosome Organization at hox Promoters during Zebrafish Embryogenesis  

PubMed Central

Nucleosome organization at promoter regions plays an important role in regulating gene activity. Genome-wide studies in yeast, flies, worms, mammalian embryonic stem cells and transformed cell lines have found well-positioned nucleosomes flanking a nucleosome depleted region (NDR) at transcription start sites. This nucleosome arrangement depends on DNA sequence (cis-elements) as well as DNA binding factors and ATP-dependent chromatin modifiers (trans-factors). However, little is understood about how the nascent embryonic genome positions nucleosomes during development. This is particularly intriguing since the embryonic genome must undergo a broad reprogramming event upon fusion of sperm and oocyte. Using four stages of early embryonic zebrafish development, we map nucleosome positions at the promoter region of 37 zebrafish hox genes. We find that nucleosome arrangement at the hox promoters is a progressive process that takes place over several stages. At stages immediately after fertilization, nucleosomes appear to be largely disordered at hox promoter regions. At stages after activation of the embryonic genome, nucleosomes are detectable at hox promoters, with positions becoming more uniform and more highly occupied. Since the genomic sequence is invariant during embryogenesis, this progressive change in nucleosome arrangement suggests that trans-factors play an important role in organizing nucleosomes during embryogenesis. Separating hox genes into expressed and non-expressed groups shows that expressed promoters have better positioned and occupied nucleosomes, as well as distinct NDRs, than non-expressed promoters. Finally, by blocking the retinoic acid-signaling pathway, we disrupt early hox gene transcription, but observe no effect on nucleosome positions, suggesting that active hox transcription is not a driving force behind the arrangement of nucleosomes at the promoters of hox genes during early development. PMID:23671670

Weicksel, Steven E.; Xu, Jia; Sagerström, Charles G.

2013-01-01

449

Coherent Somatic Mutation in Autoimmune Disease  

PubMed Central

Background Many aspects of autoimmune disease are not well understood, including the specificities of autoimmune targets, and patterns of co-morbidity and cross-heritability across diseases. Prior work has provided evidence that somatic mutation caused by gene conversion and deletion at segmentally duplicated loci is relevant to several diseases. Simple tandem repeat (STR) sequence is highly mutable, both somatically and in the germ-line, and somatic STR mutations are observed under inflammation. Results Protein-coding genes spanning STRs having markers of mutability, including germ-line variability, high total length, repeat count and/or repeat similarity, are evaluated in the context of autoimmunity. For the initiation of autoimmune disease, antigens whose autoantibodies are the first observed in a disease, termed primary autoantigens, are informative. Three primary autoantigens, thyroid peroxidase (TPO), phogrin (PTPRN2) and filaggrin (FLG), include STRs that are among the eleven longest STRs spanned by protein-coding genes. This association of primary autoantigens with long STR sequence is highly significant (). Long STRs occur within twenty genes that are associated with sixteen common autoimmune diseases and atherosclerosis. The repeat within the TTC34 gene is an outlier in terms of length and a link with systemic lupus erythematosus is proposed. Conclusions The results support the hypothesis that many autoimmune diseases are triggered by immune responses to proteins whose DNA sequence mutates somatically in a coherent, consistent fashion. Other autoimmune diseases may be caused by coherent somatic mutations in immune cells. The coherent somatic mutation hypothesis has the potential to be a comprehensive explanation for the initiation of many autoimmune diseases. PMID:24988487

Ross, Kenneth Andrew

2014-01-01

450

Somatic Symptoms in Traumatized Children and Adolescents  

ERIC Educational Resources Information Center

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.

2012-01-01

451

Endangered Wolves Cloned from Adult Somatic Cells  

Microsoft Academic Search

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

2007-01-01

452

Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems  

PubMed Central

Abstract Embryologists working with livestock species were the pioneers in the field of reprogramming by somatic cell nuclear transfer (SCNT). Without the “Dolly experiment,” the field of cellular reprogramming would have been slow and induced plutipotent cells (iPSCs) would not have been conceived. The major drive of the work in mammalian cloning was the interest of the breeding industry to propagate superior genotypes. Soon it was realized that the properties of oocytes could be used also to clone endangered mammalian species or to reprogram the genomes of unrelated species through what is known as interspecies (i) SCNT, using easily available oocytes of livestock species. iSCNT for cloning animals works only for species that can interbreed, and experiments with taxonomically distant species have not been successful in obtaining live births or deriving embryonic stem cell (ESC) lines to be used for regenerative medicine. There are controversial reports in the literature, but in most cases these experiments have underlined some of the cellular and molecular mechanisms that are incomplete during cell nucleus reprogramming, including the failure to organize nucleoli, silence somatic cell genes, activate the embryonic genome, and resume mitochondrial replication and function, thus indicating nucleus–cytoplasmic incompatibility. PMID:24033141

Lagutina, Irina; Fulka, Helena; Lazzari, Giovanna

2013-01-01

453

High frequency embryogenesis in immature zygotic embryos of sunflower  

Microsoft Academic Search

In the present investigation, nutritional requirements for induction of a high frequency of well formed somatic embryos (SEs)\\u000a from zygotic embryos (ZEs) of sunflower were assessed. Variables like genotype, embryo size (0.5–10 mm), sucrose concentration\\u000a (30–240 g l?1), carbohydrate source (sucrose, glucose, maltose), agar strength (0.2–1.0%), basal media (MS, Gamborg, Nitsch, White), photoperiod\\u000a (light\\/dark) and temperature (20–36C) were tested. All

M. Sujatha; A. J. Prabakaran

2001-01-01

454

Correction: Somatic mutations in cancer development  

PubMed Central

Since publication of Environmental Health 2011, 10(Suppl 1):S12 [1] it has been noticed that titles and captions for the figures and tables were incorrectly applied. In this full-length correction article, figures and tables have been renumbered with legends and captions applied appropriately. Some minor typographical errors have also been corrected. The inconvenience caused to readers by premature publication of the original paper is regretted. The transformation of a normal cell into a cancer cell takes place through a sequence of a small number of discrete genetic events, somatic mutations: thus, cancer can be regarded properly as a genetic disease of somatic cells. The analogy between evolution of organisms and evolution of cell populations is compelling: in both cases what drives change is mutation, but it is Darwinian selection that enables clones that have a growth advantage to expand, thus providing a larger target size for the next mutation to hit. The search for molecular lesions in tumors has taken on a new dimension thanks to two powerful technologies: the micro-arrays for quantitative analysis of global gene expresssion (the transcriptome); and ‘deep’ sequencing for the global analysis of the entire genome (or at least the exome). The former offers the most complete phenotypic characterization of a tumor we could ever hope for – we could call this the ultimate phenotype; the latter can identify all the somatic mutations in an individual tumor – we could call this the somatic genotype. However, there is definitely the risk that while we are ‘drowned by data, we remain thirsty for knowledge’. If we want to heed the teachings of Lorenzo Tomatis, I think the message is clear: we ought to take advantage of the new powerful technologies – not by becoming their slaves, but remaining their masters. Identifying somatic mutations in a tumor is important because through a deeper understanding of the nature of that particular tumor it can help us to optimize therapy or to design new therapeutic approaches.

2011-01-01

455

The ?-tocopherol transfer protein is essential for vertebrate embryogenesis.  

PubMed

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. PMID:23077608

Miller, Galen W; Ulatowski, Lynn; Labut, Edwin M; Lebold, Katie M; Manor, Danny; Atkinson, Jeffrey; Barton, Carrie L; Tanguay, Robert L; Traber, Maret G

2012-01-01

456

Modeling cell-cycle synchronization during embryogenesis in Xenopus laevis  

NASA Astrophysics Data System (ADS)

A widely conserved aspect of embryogenesis is the ability to synchronize nuclear divisions post-fertilization. How is synchronization achieved? Given a typical protein diffusion constant of 10 ?m^2sec, and an embryo length of 1mm, it would take diffusion many hours to propagate a signal across the embryo. Therefore, synchrony cannot be attained by diffusion alone. We hypothesize that known autocatalytic reactions of cell-cycle components make the embryo an ``active medium'' in which waves propagate much faster than diffusion, enforcing synchrony. We report on robust spatial synchronization of components of the core cell cycle circuit based on a mathematical model previously determined by in vitro experiments. In vivo, synchronized divisions are preceded by a rapid calcium wave that sweeps across the embryo. Experimental evidence supports the hypothesis that increases in transient calcium levels lead to derepression of a negative feedback loop, allowing cell divisions to start. Preliminary results indicate a novel relationship between the speed of the initial calcium wave and the ability to achieve synchronous cell divisions.

McIsaac, R. Scott; Huang, K. C.; Sengupta, Anirvan; Wingreen, Ned

2010-03-01

457

Role of Somatic Testicular Cells during Mouse Spermatogenesis in Three-Dimensional Collagen Gel Culture System  

PubMed Central

Objective Spermatogonial stem cells (SSCs) are the only cell type that can restore fertility to an infertile recipient following transplantation. Much effort has been made to develop a protocol for differentiating isolated SSCs in vitro. Recently, three-dimensional (3D) culture system has been introduced as an appropriate microenvironment for clonal expansion and differentiation of SSCs. This system provides structural support and multiple options for several manipulation such as addition of different cells. Somatic cells have a critical role in stimulating spermatogenesis. They provide complex cell to cell interaction, transport proteins and produce enzymes and regulatory factors. This study aimed to optimize the culture condition by adding somatic testicular cells to the collagen gel culture system in order to induce spermatogenesis progression. Materials and Methods In this experimental study, the disassociation of SSCs was performed by using a two-step enzymatic digestion of type I collagenase, hyaluronidase and DNase. Somatic testicular cells including Sertoli cells and peritubular cells were obtained after the second digestion. SSCs were isolated by Magnetic Activated Cell Sorting (MACS) using GDNF family receptor alpha-1 (Gfr?-1) antibody. Two experimental designs were investigated. 1. Gfr?-1 positive SSCs were cultured in a collagen solution. 2. Somatic testicular cells were added to the Gfr?-1 positive SSCs in a collagen solution. Spermatogenesis progression was determined after three weeks by staining of synaptonemal complex protein 3 (SCP3)-positive cells. Semi-quantitative Reverse Transcription PCR was undertaken for SCP3 as a meiotic marker and, Crem and Thyroid transcription factor-1 (TTF1) as post meiotic markers. For statistical analysis student t test was performed. Results Testicular