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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

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

Microsoft Academic Search

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

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

1997-01-01

3

Developmental Biology of Somatic Embryogenesis  

Microsoft Academic Search

\\u000a Somatic embryogenesis (SE) is a remarkable developmental process enabling nonzygotic plant cells to form embryos and, ultimately,\\u000a fertile plants. It is an expression of totipotency. This chapter initially considers the genotypic component and the progenitor\\u000a stem cells where SE is induced to form the initial asymmetric division of the somatic embryogenesis program. These cells are\\u000a part of a stem cell

R. J. Rose; F. R. Mantiri; S. Kurdyukov; S. K. Chen; X. D. Wang; K. E. Nolan; M. B. Sheahan

4

Somatic Embryogenesis in Chestnut  

Microsoft Academic Search

Somatic embryogenesis is an important biotechnological tool that demonstrates significant benefits\\u000a when applied to forest tree species; clonal propagation, cryostorage of valuable germoplasm and genetic\\u000a transformation are among the most promising of its applications. In this chapter, the state of the\\u000a art of somatic embryogenesis in chestnut (an important economical tree species of the genus Castanea) is assessed and discussed.

E. Corredoira; A. Ballester; F. J. Vieitez; A. M. Vieitez

5

Picolinic acid-induced direct somatic embryogenesis in sweet potato  

Microsoft Academic Search

Somatic embryos are being considered as an alternative material for in vitro germplasm conservation of sweet potato [(Ipomoea batatas (L.) Lam.)]. Picolinic acid was tested for somatic embryo production in sweet potato apical meristem tip cultures. Low level (0.2 mgl-1) of picolinic acid combined with kinetin or 6-benzylamino purine (6-BAP) (1.0 and 2.0 mgl-1) suppressed shoot growth and induced callus

Nenite V. Desamero; Billy B. Rhodes; Dennis R Decoteau; William C Bridges

1994-01-01

6

A novel method to induce direct somatic embryogenesis, secondary embryogenesis and regeneration of fertile green cereal plants  

Microsoft Academic Search

A direct somatic embryogenesis and secondary embryogenesis protocol was developed for seven cereal species, thus providing a new vista for in vitro plant genetic transformation or propagation. This paper describes a novel process that has been successfully developed for efficient regeneration of a wide range of cereal species and genotypes. This tissue culture and regeneration system does not require formation

F. Eudes; S. Acharya; A. Laroche; L. B. Selinger; K.-J. Cheng

2003-01-01

7

Protein Markers for Somatic Embryogenesis  

Microsoft Academic Search

The capacity for somatic embryogenesis is a remarkable property of plant cells. Somatic\\u000a embryogenesis is the process by which somatic cells develop into plants through characteristic morphological\\u000a changes, thus rendering it a good model system for studying early plant development. Most of\\u000a the important crops and grasses are recalcitrant for in vitro culturing, which hampers the development\\u000a of reliable regeneration techniques. Better

Magdalena I. Tchorbadjieva

8

Smoke-saturated water promotes somatic embryogenesis in geranium  

Microsoft Academic Search

The effect of smoke saturated-water (SSW) on somatic embryogenesis was studied using geranium hypocotyl culture as a model system. Treatment of explants with 10% SSW or the inclusion of SSW with thidiazuron, a compound which induces somatic embryogenesis, enhanced the embryogenic potential of the geranium hypocotyl culture. Prolonged exposure to SSW was detrimental to embryogenesis. The SSW treatment also accelerated

Tissa Senaratna; Kingsley Dixon; Eric Bunn; Darren Touchell

1999-01-01

9

Cloning and molecular characterisation of a potato SERK gene transcriptionally induced during initiation of somatic embryogenesis.  

PubMed

Somatic embryogenesis offers great potential in plant propagation, long-term germplasm conservation, and as a suitable model system for deciphering early events during embryogenesis. The up-regulation and ectopic expression of a SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) gene has been shown to mark and enhance embryogenic competence in somatic cells of model plant species. We have cloned and characterised a SERK gene (StSERK1) from potato (Solanum tuberosum L.), an important crop plant. Sequence analysis of StSERK1 revealed high levels of similarity to other plant SERKs, as well as a conserved intron/exon structure which is unique to members of the SERK family. Furthermore, StSERK clustered most closely with SERK gene family members such as MtSERK1, CuSERK1, AtSERK1, and DcSERK, implicated in evoking somatic embryogenesis. Monitoring of SERK expression during progression of potato somatic embryogenesis revealed increased StSERK expression during the induction phase. Subsequently, during the embryo transition phases, StSERK expression was unchanged and did not vary among embryo-forming and inhibitory conditions. However, in isolated somatic embryos StSERK expression was again up-regulated. In other plant parts (leaves, true potato seeds, microtubers and flower buds), StSERK showed different levels of expression. Expression analysis suggests that the isolated StSERK could be a functional SERK orthologue. The possible role of SERK as a marker of pluripotency, rather than embryogenesis alone, is discussed. PMID:18491133

Sharma, Sanjeev Kumar; Millam, Steve; Hein, Ingo; Bryan, Glenn J

2008-05-20

10

Regulation of Somatic Embryogenesis in Higher Plants  

Microsoft Academic Search

Somatic embryogenesis is the developmental process by which somatic cells undergo restructuring to generate embryogenic cells. These cells then go through a series of morphological and biochemical changes that result in the formation of a somatic or non-zygotic embryo capable of regenerating plants. Somatic embryogenesis represents a unique developmental pathway that includes a number of characteristic events: dedifferentiation of cells,

Xiyan Yang; Xianlong Zhang

2010-01-01

11

Direct somatic embryogenesis and synthetic seed production from Paulownia elongata  

Microsoft Academic Search

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

Z. Ipekci; N. Gozukirmizi

2003-01-01

12

Somatic embryogenesis from leaf cultures of potato  

Microsoft Academic Search

An efficient procedure has been developed for inducing somatic embryogenesis from leaf cultures of potato cv. Jyothi. Leaf sections were initially cultured on 2,4-dichlorophenoxyacetic acid (2,4-D) + benzyladenine (BA) and a-naphthaleneacetic acid (NAA) + BA supplemented Murashige and Skoog (MS) media. Nodular embryogenic callus developed from the cut ends of explants on media containing 2,4-D and BA, whereas compact callus

T. JayaSree; U. Pavan; M. Ramesh; A. V. Rao; K. Jagan Mohan Reddy; A. Sadanandam

2001-01-01

13

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

14

Effect of hydrogen peroxide on somatic embryogenesis of Lycium barbarum L  

Microsoft Academic Search

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

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

1999-01-01

15

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

Microsoft Academic Search

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

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

1996-01-01

16

Somatic embryogenesis in Mucuna pruriens  

Microsoft Academic Search

This study reports the induction of somatic embryos in Mucuna pruriens. Different explants cultured on MS medium supplemented with 11.31 µM 2,4-D produced golden yellow embryogenic callus that induced synchronized embryo development on MS basal liquid medium. Organization of pre-embryonic mass was noticed 15 d after sub culturing the callus, which progressively developed to globular, heart, torpedo and cotyledonary shaped

N. Sathyanarayana

2009-01-01

17

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

18

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

Microsoft Academic Search

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

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

1999-01-01

19

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

20

Repetitive Somatic Embryogenesis of Ocotea catharinensis Mez. (Lauraceae): Effect of Somatic Embryo Developmental Stage and Dehydration  

Microsoft Academic Search

Repetitive embryogenesis of Ocotea catharinensis from globular\\/early cotyledonary somatic embryos was successfully supported by WPM supplemented with 22.7 g l?1 sorbitol, 20 g l?1 sucrose, 400 mg l?1 glutamine and 2 g l?1 Phytagel. The best medium to induce repetitive embryogenesis in cotyledonary somatic embryos was half strength WPM supplemented\\u000a with 20 g l?1 sucrose, 400 mg l?1 glutamine, 1.5

Alessandra dos Santos Olmedo; Geraldine de Andrade Meyer; Jonice Macedo; Wagner de Amorim; Ana Maria Viana

2004-01-01

21

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

22

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

23

The use of somatic embryogenesis for plant propagation in cassava  

Microsoft Academic Search

In cassava, somatic embryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented\\u000a with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants\\u000a for a new cycle of somatic embryogenesis. The cotyledons undergo secondary somatic embryogenesis on both liquid and solid\\u000a Murashige and Skoog-based

Krit Raemakers; Evert Jacobsen; Richard Visser

2000-01-01

24

Somatic embryogenesis for agricultural improvement  

Microsoft Academic Search

Many important food and fibre crops have attained close to their maximum yields as a result of conventional breeding approaches and advances in agronomic and horticultural practices. The manipulation of cell and tissue cultures to produce somatic embryos efficiently is one of the keystones of the new technologies that will greatly alter the way crops are planted (as synthetic seed)

R. E. Litz; D. J. Gray

1995-01-01

25

Somatic embryogenesis and regeneration of Vigna radiata  

Microsoft Academic Search

An efficient regeneration protocol via somatic embryogenesis was optimized for mung bean [Vigna radiata (L.) Wilczek; cv. Vamban 1]. Primary leaf explants were used for embryogenic callus induction in MMS medium (Murashige and\\u000a Skoog salts with B5 vitamins) containing 2.0 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D), 150 mg dm?3 glutamine and 3 % sucrose. Fast growing, highly embryogenic cell suspensions were

P. Sivakumar; R. Gnanam; K. Ramakrishnan; A. Manickam

2010-01-01

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

The use of somatic embryogenesis for plant propagation in cassava.  

PubMed

In cassava, somatic embryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants for a new cycle of somatic embryogenesis. The cotyledons undergo secondary somatic embryogenesis on both liquid and solid Murashige and Skoog-based medium supplemented with auxins. Depending on the auxin, new somatic embryos are formed after 14-30 d after which they can be used for a new cycle of somatic embryogenesis. In liquid medium, more than 20 secondary somatic embryos are formed per initial cultured embryo. In both primary and secondary somatic embryogenesis, the somatic embryos originate directly from the explants. Transfer of clumps of somatic embryos to a Gresshoff and Doy-based medium supplemented with auxins results in indirect somatic embryogenesis. The direct form of somatic embryogenesis has a high potential for use in plant propagation, whereas the indirect has a high potential for use in genetic modification of cassava. Mature somatic embryos germinate into plants after desiccation and culture on a Murashige and Skoog-based medium supplemented with benzylaminopurine (BA). Depending on the used BA concentration, plants can either be transferred either directly to the greenhouse or after using standard multiplication protocols. PMID:10890012

Raemakers, K; Jacobsen, E; Visser, R

2000-03-01

28

Picomolar concentrations of salicylates induce cellular growth and enhance somatic embryogenesis in Coffea arabica tissue culture  

Microsoft Academic Search

Embryogenic cell suspension cultures of Coffea arabica cv. Caturra Rojo were treated with salicylic acid (SA). Two concentrations, 10-12 and 10-10 M, had a significant effect on the growth rate of the cell cultures when compared to the control, and this effect was concentration-dependent. These two SA concentrations also had a dramatic effect on both the number of somatic embryos

F. Quiroz-Figueroa; M. Méndez-Zeel; A. Larqué-Saavedra; V. Loyola-Vargas

2001-01-01

29

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

30

Micropropagation of Kalopanax pictus tree via somatic embryogenesis  

Microsoft Academic Search

Summary  \\u000a Kalopanax pictus (Thunb.) Nakai is a tall tree, and its wood has been used in making furniture, while its stem bark is used for medicinal\\u000a purposes. Here, we report on the micropropagation of Kalopanax pictus via somatic embryogenesis. Embryogenic callus was induced from immature zygotic embryos. The frequency embryogenic callus\\u000a induction is influenced by days of seed harvest. Callus

Heung-Kyu Moon; Yong-Wook Kim; Jae-Soon Lee; Yong-Eui Choi

2005-01-01

31

Somatic embryogenesis and plant regeneration in Gymnema sylvestre  

Microsoft Academic Search

Somatic embryogenesis and whole plant regeneration were achieved in callus cultures derived from hypocotyl, cotyledon and leaf explants excised from seedlings of Gymnema sylvestre. Embryogenic callus was induced on Murashige and Skoog (MS) medium containing 2,4-D (0.5–5.0 µM) +BA (0.5–2.0 µM) and 2% (w\\/v) sucrose in 6–8 weeks of culture. Globular\\/heart stage embryos developed on induction medium. These embryos produced

H. G. Ashok Kumar; H. N. Murthy; K. Y. Paek

2002-01-01

32

Hemoglobins, programmed cell death and somatic embryogenesis.  

PubMed

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

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

2013-06-24

33

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

34

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

35

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

Microsoft Academic Search

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

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

2002-01-01

36

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

Microsoft Academic Search

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

Cui Kairong; Xing Gengmei; Wang Lihong; Wang Yafu

2002-01-01

37

Plant regeneration via somatic embryogenesis in chick pea ( Cicer arietinum L.)  

Microsoft Academic Search

Five genotypes of chickpea (Cicer arietinum L.) PG1, PG5, PG12, N59 and C235 were evaluated for induction of somatic embryogenesis. Somatic embryogenesis was induced from immature cotyledons of genotypes PG12 and C235 and immature embryo axes of genotypes PG5, PG12 and C235. Genotypes N59 and PG1 showed no response. The maximum frequency of globular embryo formation occurred in cotyledonary segments

A. P. Sagare; K. Suhasini; K. V. Krishnamurthy

1993-01-01

38

Somatic embryogenesis and plant regeneration in wild cotton ( Gossypium klotzschianum )  

Microsoft Academic Search

A simple and efficient method for high frequency somatic embryogenesis and plant regeneration from hypocotyl-derived cultures and suspension cultures of Gossypium klotzschianum Anderss, a wild, diploid species of cotton is described here. Embryogenic cultures were induced from hypocotyl sections on MSB medium with 0.9 µM 2,4-D and 2.32 µM kinetin. MSB medium containing 0.045 µM 2,4-D, 0.93 µM kinetin, 2.46

Yuqiang Sun; Xianlong Zhang; Shuangxia Jin; Shaoguang Liang; Yichun Nie

2003-01-01

39

High frequency somatic embryogenesis and plant regeneration of an elite Chinese cotton variety  

Microsoft Academic Search

An elite Chinese cotton (Gossypium hirsutum L.) cultivar Simian-3 was chosen for tissue culture. Callus with a high frequency of somatic embryogenesis, somatic embryos, and regenerative plants was obtained. Callus was induced from three types of explants on MSB (MS salts with B 5 vitamins) medium supplemented with zeatin (ZT) only, but the percentage of callus induction and growth of

Bao-Hong Zhang; Rong Feng; Fang Liu; Qinglian Wang

2001-01-01

40

PUTRESCINE ENHANCES SOMATIC EMBRYOGENESIS AND PLANT REGENERATION IN UPLAND COTTON  

Technology Transfer Automated Retrieval System (TEKTRAN)

An efficient plant transformation system depends, in large part, on the capability of the cells to produce somatic embryos (SEs) and to then produce plants. Improvement in somatic embryogenesis has been achieved in several Georgia and Pee Dee cotton lines with media containing various putrescine (P...

41

Somatic embryogenesis of Myrciaria aureana (Brazilian grape tree)  

Microsoft Academic Search

The aim of this research was to establish a long-term somatic embryogenic cultures that could be used for cryopreservation.\\u000a For the induction of somatic embryogenesis, different levels of 2,4-D as well as the combination of 2,4-D and indole-3-acetyl-l-aspartic acid (IASP) were tested on cotyledons of zygotic embryos. The somatic embryogenic cultures were established and\\u000a maintained up to 2 years through frequent

Sergio Yoshimitsu Motoike; Edson Santana Saraiva; Marilia Contin Ventrella; Crislene Viana Silva; Luiz Carlos Chamhum Salomăo

2007-01-01

42

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

43

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

44

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

45

Shoot apex explants for induction of somatic embryogenesis in mature Quercus robur L. trees  

Microsoft Academic Search

A procedure for inducing somatic embryos in shoot apex explants (2 mm) excised from shoot proliferation cultures established\\u000a from adult oak trees (Quercus robur) was investigated. Embryogenesis was induced in shoot tip as well as leaf explants in three out of the five genotypes evaluated.\\u000a Somatic embryos were formed by culture in induction medium supplemented with 21.48 ?M naphthalene acetic acid and

E. Corredoira; M. T. Martínez; N. Vidal; S. Valladares; R. Mallón; A. M. Vieitez

2010-01-01

46

Somatic embryogenesis and plant regeneration from petioles of Parthenocissus tricuspidata planch  

Microsoft Academic Search

Summary  A protocol of somatic embryogenesis and plant regeneration from petiole segments of Parthenocissus tricuspidata Planch. has been developed. Embryogenic tissue was induced on B5 (Gamborg) basal medium supplemented with 2.25–9.0 ?M 2,4-dichlorophenoxyacetic acid, 500 mg l?1 casein hydrolysate (CH), and 0.1 gl?1 activated charcoal. Somatic embryos were induced on B5 medium containing various concentrations of benzyladenine (BA) (4.44,\\u000a 6.66, and

Yongxue Yang; Guofeng Liu; Manzhu Bao

2006-01-01

47

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

PubMed Central

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

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

2011-01-01

48

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

49

Somatic embryogenesis in macaw palm ( Acrocomia aculeata) from zygotic embryos  

Microsoft Academic Search

Macaw palm (Acrocomia aculeata) is an oleaginous palm tree that is highly productive and adapted to semiarid ecosystems, which oil can be used to produce biodiesel. Such characteristics make macaw palm a potential crop to be used by farmers from semi-arid regions, but its propagation is still problematic. This paper reports the first description of somatic embryogenesis for macaw palm

Elisa Ferreira Moura; Sérgio Yoshimitsu Motoike; Marília Contin Ventrella; Adauto Quirino de Sá Júnior; Mychelle Carvalho

2009-01-01

50

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 ...

51

Repetitive somatic embryogenesis in Medicago truncatula ssp. Narbonensis and M. truncatula Gaertn cv. Jemalong  

Microsoft Academic Search

Medicago truncatula ssp Narbonensis and four genotypes of M. truncatula Gaertn cv. Jemalong were tested for their somatic embryogenesis potential using a two-step protocol. In the first step, embryogenic\\u000a callus was induced in folioles isolated from shoots grown in vitro and cultured on Murashige and Skoog (MS) medium supplemented\\u000a with 2,4-dichlorophenoxyacetic acid and zeatin. In the second step, somatic embryos

L. O. das Neves; S. R. L. Duque; J. S. de Almeida; P. S. Fevereiro

1999-01-01

52

Control of somatic embryogenesis and embryo development by AP2 transcription factors.  

PubMed

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. PMID:20798978

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

2010-08-27

53

Enhancement of somatic embryogenesis frequency by gibberellic acid in fennel  

Microsoft Academic Search

The effect of GA3 on somatic embryogenesis from petiole fragments excised from micropropagated fennel plantlets was studied. Explants were maintained for 4 weeks on an induction medium containing, 2,4-d and kinetin and were then transferred to a medium devoid of these growth regulators to allow embryo development. The addition of autoclaved or filter-sterilized GA3 to the induction medium or to

Gérard Hunault; Abdelaziz Maatar

1995-01-01

54

Somatic embryogenesis efficiently eliminates viroid infections from grapevines  

Microsoft Academic Search

Indirect somatic embryogenesis is effective at eliminating the most important viruses affecting grapevines. Accordingly, this\\u000a technique was tested as a method for eradicating two widespread viroids, Grapevine yellow speckle viroid 1 (GYSVd-1) and Hop stunt viroid (HSVd), from four grapevine cultivars. Both viroids were detected by RT-PCR in grapevine floral explants used for initiating\\u000a embryogenic cultures, as well as in

Giorgio Gambino; Beatriz Navarro; Rosalina Vallania; Ivana Gribaudo; Francesco Di Serio

55

Application of somatic embryogenesis to tree improvement in conifers  

Microsoft Academic Search

Somatic embryogenesis (SE) offers advantages in tree breeding due to the genetic gain improvements that can be realized through selection and production of elite (clonal) lines. Additionally, it is a platform through which value-added traits can be introduced via genetic engineering.At CellFor considerable effort has been directed towards the improvement of SE protocols for coniferous species, with significant focus placed

David R. Cyr; Stephen M. Attree; Yousry A. El-Kassaby; David D. Ellis; Dan R. Polonenko; Ben C. S. Sutton

2001-01-01

56

An efficient regeneration system via somatic embryogenesis in olive  

Microsoft Academic Search

Olive is one of the most important oil crops in the Mediterranean area. Biotechnological improvement of this species is hampered\\u000a by the recalcitrant nature of olive tissue regeneration in vitro. In this investigation, we have developed an efficient regeneration\\u000a system for juvenile olive explants via somatic embryogenesis. Embryogenic cultures were obtained at a rate of 25% by culturing\\u000a isolated radicles from

Sergio Cerezo; José A. Mercado; Fernando Pliego-Alfaro

2011-01-01

57

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

2013-06-20

58

Pepper ( capsicum annuum L.) regenerants obtained by direct somatic embryogenesis fail to develop a shoot  

Microsoft Academic Search

Summary  Three auxin-type herbicides, namely 2.4-dichlorophenoxyacetic acid (2,4-D), (4-chlorophenoxy)acetic acid 2-(dimethylamino)ethyl\\u000a ester (centrophenoxine), and quinolinecarboxylic acid (quinclorac) induced direct somatic embryogenesis in seed-derived zygotic\\u000a embryo explants of sweet pepper (Capsicum annuum L.) when added to Murashige and Skoog medium with 200 mM sucrose. Optimum concentrations for embryogenesis induction were 0.40–0.45 mM and 1.15–1.30 ?M for 2.4-D and centrophenoxine, respectively (in the

Benjamin Steinitz; Mustafa Küsek; Yona Tabib; Ilan Paran; Aaron Zelcer

2003-01-01

59

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

60

Plant regeneration via somatic embryogenesis in ginger  

Microsoft Academic Search

Embryogenic callus cultures of ginger were induced from young leaf segments taken from in vitro shoot cultures. Among the four auxins tested in Murashige & Skoog medium, dicamba at 2.7 µM was most effective in inducing and maintaining embryogenic cultures. Efficient plant regeneration was achieved when embryogenic cultures were transferred to Murashige & Skoog medium containing 8.9 µM benzyladenine. Histological

A. Kackar; S. R. Bhat; K. P. S. Chandel; S. K. Malik

1993-01-01

61

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

62

Improvement of somatic embryogenesis and plantlet conversion in Oplopanax elatus, an endangered medicinal woody plant.  

PubMed

Oplopanax elatus is a medicinal plant on the verge of extinction because of overexploitation. In the present study, the effects of various factors on enhancing somatic embryogenesis and plantlet conversion were studied. Mature seeds were collected from a total of 13 plants from 4 mountains in South Korea, and the genetic distances were calculated to analyze the effect of genotype on somatic embryogenesis. Results of cluster analysis and the unweighted-pair-group method with arithmetic mean of 13 genotypes indicated the presence of 3 main groups. Both genotype and explant type affected the induction of somatic embryos (SEs). Sorak 2 and root were found to be the most suitable genotype and explant type, respectively, for SE induction in O. elatus. Among the different types of carbon sources tested, 5% sucrose induced the maximum number of SEs. The formation and development of SEs were significantly influenced by culture density; thus, 10 mg embryonic callus was found to be the most suitable for SE induction. The highest rates of germination and SE conversion were obtained in a germination medium containing 1.8 gelrite and 3.2 g·l(-1) agar. In addition, 80% of the plantlets that were transplanted into artificial soil acclimatized successfully. Thus, our results showed that the percentage survival of O. elatus during in vitro proliferation could be increased by optimizing to the somatic embryogenesis system. PMID:24024109

Moon, Heung-Kyu; Kim, Yong-Wook; Hong, Yong-Pyo; Park, So-Young

2013-08-31

63

Somatic embryogenesis and plant regeneration of Lilium ledebourii (Baker) Boiss., an endangered species  

Microsoft Academic Search

A somatic embryogenesis (SE) protocol was established for the regeneration of Lilium ledebourii (Baker) Boiss. whole plants using new vegetative bulblet microscales and transverse thin cell layers (tTCLs) of young bulblet\\u000a roots as the explant sources. Bulblets were induced from bulb scale explants cultured for at least 3 months in the dark on\\u000a Murashige and Skoog (MS) medium containing 3%

Mehdi BakhshaieMesbah Babalar; Mesbah Babalar; Masoud Mirmasoumi; Ahmad Khalighi

2010-01-01

64

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

Microsoft Academic Search

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

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

2010-01-01

65

Somatic embryogenesis in Narcissus pseudonarcissus cvs. Golden Harvest and St. Keverne  

Microsoft Academic Search

Somatic embryos (SEs) have been produced from bulb and shoot culture leaf explants of Narcissus pseudonarcissus cvs. Golden Harvest and St. Keverne. Initial experiments with cv. Golden Harvest resulted in SEs from leaf lamina, leaf base, bulb scale and scape (flower stem) explants. Embryogenesis was induced on media with a range of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP) concentrations. There

Darren O Sage; James Lynn; Neil Hammatt

2000-01-01

66

Plant regeneration via somatic embryogenesis in mung bean [ Vigna radiata (L.) Wilczek  

Microsoft Academic Search

Somatic embryogenesis was induced from mature cotyledons, hypocotyl, nodal segment, and leaf explants of two Indian cultivars of Vigna radiata (L.) Wilczek on Murashige and Skoog’s medium supplemented with several combinations of growth regulators. The greatest response was obtained with the combination 1.809?M 2,4-dichlorophenoxyacetic acid (2,4-D) with 3.555?M benzyl adenine (BA). Better response was obtained when cultures were incubated under

Prathibha Devi; P Radha; L Sitamahalakshmi; D Syamala; S Manoj Kumar

2004-01-01

67

Characterization of expressed sequence tags obtained by SSH during somatic embryogenesis in Cichorium intybus L  

Microsoft Academic Search

Background  Somatic embryogenesis (SE) is an asexual propagation pathway requiring a somatic-to-embryonic transition of differentiated\\u000a somatic cells toward embryogenic cells capable of producing embryos in a process resembling zygotic embryogenesis. In chicory,\\u000a genetic variability with respect to the formation of somatic embryos was detected between plants from a population of Cichorium intybus L. landrace Koospol. Though all plants from this population

Sylvain Legrand; Theo Hendriks; Jean-Louis Hilbert; Marie-Christine Quillet

2007-01-01

68

Somatic embryogenesis and plant regeneration in different organs of Euterpe edulis mart. (Palmae): Control and structural features  

Microsoft Academic Search

Somatic embryogenesis and further plant regeneration were observed using zygotic embryos, young inflorescences and young leaves\\u000a ofEuterpe edulis (Palmae) as explants. Both for the cultures of zygotic embryos and inflorescences, activated charcoal in the medium was essential\\u000a for the establishment of viable cultures. Embryogenesis was induced by using a gelled basal medium with MS or Euwens salts\\u000a supplemented by high

Miguel P. Guerra; Walter Handro

1998-01-01

69

Observations on the combined effects of light, NAA and 2,4-D on somatic embryogenesis of cucumber ( Cucumis sativus ) hybrids  

Microsoft Academic Search

Somatic embryogenesis of cucumber was affected by auxin and light during the induction phase. In the light, 2,4-dichlorophenoxyacetic\\u000a acid (2,4-D) alone induced little embryogenesis, while combined with naphthaleneacetic acid (NAA) it induced 1.25 somatic\\u000a embryos (SEs) per callus. In the dark 2,4-D alone induced 5 times more SEs per callus.

Khaled M. Suliman Elmeer; Michael J. Hennerty

2008-01-01

70

Micropropagation of Citrus spp. by organogenesis and somatic embryogenesis.  

PubMed

Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstocks, and it is very useful also for breeding and germplasm preservation.In this chapter, two protocols regarding organogenesis of a rootstock and somatic embryogenesis of a cultivar have been described. PMID:23179693

Chiancone, Benedetta; Germanŕ, Maria Antonietta

2013-01-01

71

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. ...

72

Somatic embryogenesis and fertile green plant regeneration from suspension cell-derived protoplasts of rye ( Secale cereale L.)  

Microsoft Academic Search

A method for somatic embryogenesis and fertile green plant regeneration from suspension cell-derived protoplasts of rye ( Secale cereale L. cv. Auvinen) was developed. Fast-growing and friable embryogenic calli with a high regeneration capacity were induced from immature rye inflorescences using modified MS medium. These friable embryogenic calli were used for suspension culture initiation in liquid AA medium. A high

R. Ma; Y.-D. Guo; S. Pulli

2003-01-01

73

Morphological evaluation of olive plants propagated in vitro culture through axillary buds and somatic embryogenesis methods  

Microsoft Academic Search

The morphological fidelity of the olive plants propagated through axillary buds, microplants and somatic embryogenesis, somatic plants was evaluated. Thirty-two morphological traits were used to characterize the tissue culture propagated olive plants. The microplants showed very high phenotypic similarity compared to plants produced by conventional cutting propagation method. The somatic plants exhibited variant morphological stable phenotypes, among somaclonal population two

Leva Annarita

74

In vitro plant regeneration via somatic embryogenesis through cell suspension cultures of horsegram [ Macrotyloma uniflorum (Lam.) verdc.  

Microsoft Academic Search

Summary  \\u000a In vitro regeneration of plants via somatic embryogenesis through cell suspension culture was achieved in horsegram. Embryogenic calluses\\u000a were induced on leaf segments on solid Murashige and Skoog (MS) medium with 9.0 ?M 2,4-dichlorophenoxyacetic acid (2,4-D). Differentiation of somatic embryos occurred when the embryogenic calluses were transferred\\u000a to liquid MS medium containing 2,4-D. Maximum frequency (33.2%) of somatic embryos

S. Varisai Mohamed; C. S. Wang; M. Thiruvengadam; N. Jayabalan

2004-01-01

75

Influence of abscisic acid and sucrose on somatic embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa.  

PubMed

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

2013-06-12

76

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.

Lema-Ruminska, J.; Goncerzewicz, K.; Gabriel, M.

2013-01-01

77

Comparative Efficacy of Abscisic Acid and Methyl Jasmonate for Indirect Somatic Embryogenesis in Medicago sativa L  

Microsoft Academic Search

The effects of methyl jasmonate (MeJA) in relation to abscisic acid (ABA) on different phases of somatic embryogenesis were\\u000a studied in Medicago sativa L. Different concentrations of both the growth inhibitors (0.0, 0.5, 5.0, 50.0 and 500.0 ?M) were tested in five distinct phases of somatic embryogenesis, viz., induction, proliferation, differentiation, maturation\\u000a and regeneration. Like ABA, MeJA also inhibited callus induction,

Izabela Rudu?; Ewa K?pczy?ska; Jan K?pczy?ski

2006-01-01

78

Somatic embryogenesis from callus cultures of Terminalia chebula Retz.: an important medicinal tree  

Microsoft Academic Search

Somatic embryogenesis was obtained from cotyledon and mature zygotic embryo callus cultures of Terminalia chebula Retz. Callus cultures of cotyledon and mature zygotic embryo were initiated on induction medium containing Murashige and Skoog (MS) nutrients with 1.0 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D) either 0.01 or 0.1 mg\\/l Kinetin and 30 g\\/l sucrose. Induction of somatic embryogenesis, proliferation and development was obtained through different culture

C. Anjaneyulu; B. Shyamkumar; C. C. Giri

2004-01-01

79

Field performance of Theobroma cacao L. plants propagated via somatic embryogenesis  

Microsoft Academic Search

Somatic embryogenesis is an in vitro clonal propagation method with potential to contribute to the improvement of cacao varieties. Before using this technology\\u000a for commercial production, it is essential that somatic embryogenesis-derived plants be tested in field conditions. Therefore,\\u000a we established a field test at Union Vale Estate, Saint Lucia. Thirty- to 50-yr-old trees were selected for clonal propagation\\u000a as

Siela N. Maximova; Ann Young; Sharon Pishak; Mark J. Guiltinan

2008-01-01

80

Direct somatic embryogenesis from leaves, cotyledons and hypocotyls of Hippophae rhamnoides  

Microsoft Academic Search

Plant regeneration via direct somatic embryogenesis from cotyledons, hypocotyls and leaves in seabuckthorn (Hippophae rhamnoides L.) was achieved. The influences of basal media, carbon sources, plant growth regulators (PGRs) with different concentrations\\u000a and combinations on embryogenesis capacity of explants were studied. The highest frequency of somatic embryos production and\\u000a germination was obtained on Schenk and Hildebrandt medium (SH) supplemented with

C. Q. Liu; X. L. Xia; W. L. Yin; J. H. Zhou; H. R. Tang

2007-01-01

81

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

Microsoft Academic Search

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

Anca Lucau-Danila; Laurent Laborde; Sylvain Legrand; Ludovic Huot; David Hot; Yves Lemoine; Jean-Louis Hilbert; Simon Hawkins; Marie-Christine Quillet; Theo Hendriks; Anne-Sophie Blervacq

2010-01-01

82

Micropropagation of Codiaeum variegatum (L.) Blume and regeneration induction via adventitious buds and somatic embryogenesis.  

PubMed

Codiaeum variegatum (L) Blume cv. "Corazon de oro" and cv. "Norma" are successfully micropropagated when culture are initiated with explants taken from newly sprouted shoots. The establishment and multiplication steps are possible when 1 mg/L BA or 1 mg/L IAA and 3 mg/L 2iP are added to MS medium, according to the cultivar respectively selected.Adventive organogenesis and somatic embryogenesis are induced from leaf explants taken from in vitro buds of croton. On leaf-sectioned of "Corazon de oro" cultured in vitro, 1 mg/L BA stimulates continuous somatic embryos development and induces some shoots too. Replacing BA with 1 mg/L TDZ induces up to 100% bud regeneration in the same explants. On the other hand, leaf-sectioned of C. variegatum cv. Norma does not start somatic embryo differentiation if 1 mg/L TDZ is not added to the MS basal medium. Incipient callus is observed after 30 days of culture, and then, subculture to MS with 1 mg/L BA allows the same process to show on the "Corazon de oro" cultivar. Somatic embryos show growth arrest that is partially overcome by transfer to hormone-free basal medium with activated charcoal. Root induction is possible on basal medium plus 1 mg/L IBA. Plantlets in the greenhouse have variegated leaves true-to-type. PMID:20099102

Radice, Silvia

2010-01-01

83

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

84

Plant regeneration via somatic embryogenesis in creeping bentgrass ( Agrostis palustris Huds.)  

Microsoft Academic Search

We have established a high-frequency plant regeneration system via somatic embryogenesis from mature seeds of creeping bentgrass (Agrostis palustris Huds). The effects of 2,4-dichlorophenoxyacetic acid (2,4-D), 3.6-dichloroo-anisic acid (dicamba) and 6-benzyladenine (BA) on callus formation and embryogenesis were evaluated. Callus produced on the Murashige and Skoog (MS) (1962) medium containing 2,4-D had low embryogenic potency. In the presence of 30

Heng Zhong; C. Srinivasan; Mariam B. Sticklen

1991-01-01

85

Repetitive somatic embryogenesis in peanut cotyledon cultures by continual exposure to 2,4-d  

Microsoft Academic Search

Somatic embryos from immature cotyledons in peanut (Arachis hypogaea) were initiated on media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-d). Over 90% primary embryogenesis and 41–46% repetitive embryogenesis were obtained 12 weeks after initiation by maintaining embryogenic cultures on medium containing 20 mg 1-1 2,4-d. Maintenance of cultures on medium with 30 or 40 mg I-1 2,4-d resulted in lower primary and

Charleen M. Baker; Hazel Y. Wetzstein

1995-01-01

86

Callose Deposition Is Required for Somatic Embryogenesis in Plasmolyzed Eleutherococcus senticosus Zygotic Embryos  

PubMed Central

Dynamic changes in callose content, which is deposited as a plant defense response to physiological changes, were analyzed during somatic embryogenesis in Eleutherococcus senticosus zygotic embryos plasmolyzed in 1.0 M mannitol. During plasmolysis, callose deposition was clearly observed inside the plasma membrane of zygotic embryo epidermal cells using confocal laser scanning microscopy. The callose content of zygotic embryos gradually increased between 0 and 12 h plasmolysis and remained stable after 24 h plasmolysis. During eight weeks induction of somatic embryogenesis, the callose content of explants plasmolyzed for 12 h was slightly higher than explants plasmolyzed for 6 or 24 h, with the largest differences observed after 6 weeks culture, which coincided with the maximum callose content and highest number of globular somatic embryos. The highest frequency of somatic embryo formation was observed in explants plasmolyzed for 12 h. The somatic embryo induction rate and number of somatic embryos per explant were markedly different in zygotic embryos pretreated with plasmolysis alone (78.0%, 43 embryos per explant) and those pretreated with plasmolysis and the callose synthase inhibitor 2-deoxy-d-glucose (11.5%, 8 embryos per explant). This study indicates that callose production is required for somatic embryogenesis in plasmolyzed explants.

Tao, Lei; Yang, Yang; Wang, Qiuyu; You, Xiangling

2012-01-01

87

Analysis of genetic stability at SSR loci during somatic embryogenesis in maritime pine (Pinus pinaster).  

PubMed

Somatic embryogenesis (SE) is a propagation tool of particular interest for accelerating the deployment of new high-performance planting stock in multivarietal forestry. However, genetic conformity in in vitro propagated plants should be assessed as early as possible, especially in long-living trees such as conifers. The main objective of this work was to study such conformity based on genetic stability at simple sequence repeat (SSR) loci during somatic embryogenesis in maritime pine (Pinus pinaster Ait.). Embryogenic cell lines (ECLs) subjected to tissue proliferation during 6, 14 or 22 months, as well as emblings regenerated from several ECLs, were analyzed. Genetic variation at seven SSR loci was detected in ECLs under proliferation conditions for all time points, and in 5 out of 52 emblings recovered from somatic embryos. Three of these five emblings showed an abnormal phenotype consisting mainly of plagiotropism and loss of apical dominance. Despite the variation found in somatic embryogenesis-derived plant material, no correlation was established between genetic stability at the analyzed loci and abnormal embling phenotype, present in 64% of the emblings. The use of microsatellites in this work was efficient for monitoring mutation events during the somatic embryogenesis in P. pinaster. These molecular markers should be useful in the implementation of new breeding and deployment strategies for improved trees using SE. PMID:19153739

Marum, Liliana; Rocheta, Margarida; Maroco, Joăo; Oliveira, M Margarida; Miguel, Célia

2009-01-20

88

Cloning, molecular characterization and expression analysis of a SOMATIC EMBRYOGENESIS RECEPTOR - LIKE KINASE gene ( CitSERK1 - like ) in Valencia sweet orange  

Microsoft Academic Search

Somatic embryogenesis receptor-like kinase (SERK) belonging to the receptor-like kinases (RLKs) has been shown to be implicated in somatic embryogenesis (SE). In this study, a somatic embryogenesis receptor-like\\u000a gene CitSERK1-like was cloned and characterized from Citrus sinensis cv. ‘Valencia’, a genotype with high somatic embryogenesis capacity for over 26 years. Fifteen consecutive amino acids in\\u000a putative leucine zipper domain of CitSERK1-like

Xiao-Xia Ge; Gai-En Fan; Li-Jun Chai; Wen-Wu Guo

2010-01-01

89

Somatic embryogenesis and plant regeneration in Floribunda rose ( Rosa hybrida L.) cvs. Trumpeter and Glad Tidings  

Microsoft Academic Search

Somatic embryogenic callus was initiated from in vitro-derived petiole and root explants, but not leaves, of the Floribunda rose cultivars Trumpeter and Glad Tidings following repeated subculture of callus on Schenk and Hildebrandt (SH) medium containing 2,4-dichlorophenoxyacetic acid (2,4-D). The use of a high auxin pretreatment increased the frequency of somatic embryogenesis, whilst l-proline, as a media supplement, had a

Robert Marchant; Michael R. Davey; John A. Lucas; J. Brian Power

1996-01-01

90

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

91

Improvement of somatic embryogenesis in wild cherry (Prunus avium). Effect of maltose and ABA supplements  

Microsoft Academic Search

Three different types of morphogenesis were identified in embryogenic cultures of Prunus avium grown on a proliferation medium\\u000a containing 0.54 ?M NAA, 0.46 ?M kinetin and 0.44 ?M BA: a friable hyperhydric callus, repetitive embryogenesis and an embryogenic\\u000a tissue. Translucent and white somatic embryos were produced from the three types of morphogenesis but mainly from the embryogenic\\u000a tissue. These somatic

Lydia Reidiboym-Talleux; Florence Diemer; Martine Sourdioux; Kathy Chapelain; Ghislaine Grenier-De March

1998-01-01

92

Plant regeneration via somatic embryogenesis in pigeonpea (Cajanus cajan L. Millsp)  

Microsoft Academic Search

Efficient plant regeneration via somatic embryogenesis has been developed in pigeonpea. Cotyledon and leaf explants from\\u000a 10-day-old seedlings produced embryogenic callus and somatic embryos when cultured on Murashige and Skoog (MS) medium supplemented\\u000a with 10 µm thidiazuron (TDZ). Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos\\u000a into plantlets on MS basal

K. Sreenivasu; S. K. Malik; P. Ananda Kumar; R. P. Sharma

1998-01-01

93

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

Microsoft Academic Search

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 µM), thidiazuron (10 µM) and a high concentration of sucrose (6–10%). The best

Marla L. Binzel; N. Sankhla; Sangeeta Joshi; Daksha Sankhla

1996-01-01

94

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

2012-01-22

95

Isolation of two genes that were induced upon the initiation of somatic embryogenesis on carrot hypocotyls by high concentrations of 2,4-D  

Microsoft Academic Search

This study describes the formation of somatic embryos directly on the surface of hypocotyl sections of Daucus carota L. after exposure to 450??M of 2,4-D for 2?h, followed by culturing without 2,4-D for 2 weeks. A search for differentially expressed genes immediately\\u000a after the 2,4-D treatment resulted in the identification of two genes, Dchsp-1 and Dcarg-1. Dchsp-1 has homology to

E. Kitamiya; S. Suzuki; T. Sano; T. Nagata

2000-01-01

96

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

2012-11-22

97

Characteristics of Bupleurum falcatum plants propagated through somatic embryogenesis of callus cultures  

Microsoft Academic Search

Various characteristics including the saponin content in the root of Bupleurum falcatum plants propagated in vitro through somatic embryogenesis of callus cultures were compared with those of the plants propagated by seeds. The asexually propagated plants had an aerial part of more uniform characteristics than those of sexually propagated ones. However, both the mean and variance of root weight of

Noboru Hiraoka; Tomoko Kodama; Miho Oyanagi; Shihoko Nakano; Yutaka Tolnita; Nobuyuki Yamada; Osamu Iida; Motoyoshi Satake

1986-01-01

98

Tunicamycin-inhibited carrot somatic embryogenesis can be restored by secreted cationic peroxidase isoenzymes  

Microsoft Academic Search

Somatic embryogenesis of carrot (Daucus carota L.) is inhibited by the glycosylation inhibitor tunicamycin. This inhibition is reversible by the addition of correctly glycosylated glycoproteins which have been secreted into the culture medium. To identify the proteins responsible for complementation, glycoproteins present in the medium of embryo cultures were purified and tested for their activity in the tunicamycin inhibition\\/ complementation

J. H. G. Cordewener; Hiibert Booij; Hans van der Zandt; Fred van Engelen; Ab van Kammen; Sacco de Vries

1991-01-01

99

Somatic embryogenesis and regeneration of plants in the bamboo Dendrocalamus strictus  

Microsoft Academic Search

Somatic embryogenesis leading to plant regeneration has been achieved in the bamboo, Dendrocalamus strictus, by culturing seeds (caryopses) on B5 basal medium supplemented with 2,4-dichlorophenoxyacetic acid. Callus cultures obtained from the embryonal end of the seeds differentiated chlorophyllous embryoids. On transfer to a germination medium (B5 liquid, sucrose, indolebutyric acid, and ? -naphthaleneacetic acid) 40% of the embryoids developed into

I. Usha Rao; I. V. Ramanuja Rao; Vibha Narang

1985-01-01

100

Regeneration of different Cyclamen species via somatic embryogenesis from callus, suspension cultures and protoplasts  

Microsoft Academic Search

The present study is the first report of the establishment of embryogenic callus cultures from seedling tissue, the regeneration of plants via somatic embryogenesis and the development of a regeneration system from protoplast to plant, using three wild species of Cyclamen, Cyclamen graecum Link, Cyclamen mirabile Hildebrand, Cyclamen trochopteranthum Schwarz (syn. Cyclamen alpinum hort. Dammann ex Sprenger). The ability to

Anika Nadja Sabine Prange; Melanie Bartsch; Margrethe Serek; Traud Winkelmann

2010-01-01

101

High Frequency of Plant Regeneration through Cyclic Secondary Somatic Embryogenesis in Panax ginseng  

PubMed Central

Somatic embryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somatic embryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal.

Kim, Yu-Jin; Lee, Ok Ran; Kim, Kyung-Tack; Yang, Deok-Chun

2012-01-01

102

High Frequency of Plant Regeneration through Cyclic Secondary Somatic Embryogenesis in Panax ginseng.  

PubMed

Somatic embryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somatic embryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal. PMID:23717148

Kim, Yu-Jin; Lee, Ok Ran; Kim, Kyung-Tack; Yang, Deok-Chun

2012-10-01

103

Unfertilized ovary: a novel explant for coconut (Cocos nucifera L.) somatic embryogenesis.  

PubMed

Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somatic embryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 microM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somatic embryogenesis induction medium containing 5 microM abscisic acid, followed by plant regeneration medium (with 5 microM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somatic embryogenesis including orientation, polarization and elongation of the embryos. PMID:16902798

Perera, Prasanthi I P; Hocher, Valerie; Verdeil, Jean Luc; Doulbeau, Sylvie; Yakandawala, Deepthi M D; Weerakoon, L Kaushalya

2006-08-11

104

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

105

Synchronization of somatic embryogenesis from carrot cells at high frequency as a basis for the mass production of embryos  

Microsoft Academic Search

Synchronization of somatic embryogenesis at high frequency is a useful system for the mass production of embryos. Many attempts have been carried out, however, it was difficult to obtain the system in which most of the initial embryogenic cells or cell clusters synchronously differentiate to embryos. In carrot suspension cultures, high frequency, synchronous embryogenesis systems (following three systems) have been

Koichi Osuga; Atsushi Komamine

1994-01-01

106

The role of salicylic acid and carrot embryogenic callus extracts in somatic embryogenesis of naked oat ( Avena nuda )  

Microsoft Academic Search

Enhanced somatic embryogenesis and plant regeneration have been obtained using young leaf bases of naked oat (Avena nuda) as explants by including salicylic acid (SA) and carrot embryogenic callus extracts (CECE) in media. A 5- and 4-fold improvement\\u000a was achieved in somatic embryogenesis and plant regeneration on the corresponding media supplemented with 0.5 mM SA and CECE\\u000a as compared to control,

Lin Hao; Lina Zhou; Xin Xu; Jun Cao; Ti Xi

2006-01-01

107

Efficient plant regeneration through direct somatic embryogenesis from leaf explants of Phalaenopsis ‘Little Steve’  

Microsoft Academic Search

Summary  Leaf segments of the orchid sp. Phalaenopsis ‘Little Steve’ were used as explants testing the effects of 2,4-dichlorophenoxyacetic acid (2,4-D; 0.45, 2.26, 4.52 ?M), 6-furfurylaminopurine (kinetin; 2.32, 4.65, 13.95 ?M), N6-benzyladenine (BA; 2.22, 4.44, 13.32 ?M), and 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ; 2.27, 4.54, 13.62?M) on the induction of direct somatic embryogenesis. After 20–30 d of culture in darkness, clusters of somatic embryos

Huei-Lan Kuo; Jen-Tsung Chen; Wei-Chin Chang

2005-01-01

108

Regeneration and large-scale propagation of bamboo (Dendrocalamus strictus Nees) through somatic embryogenesis  

Microsoft Academic Search

A complete protocol for large-scale propagation of Dendrocalamus strictus Nees by somatic embryogenesis has been developed. Seeds cultured on agar-solidified Murashige and Skoog (MS) medium supplemented\\u000a with 2,4-dichlorophenoxyacetic acid (2,4-D; 3×10–5\\u000a m) produced embryogenic callus from proliferation of the embryo. Somatic embryos formed in vitro multiplied rapidly (two- to\\u000a five fold every 5 weeks) on semi-solid MS medium containing 2,4-D

S. Saxena; V. Dhawan

1999-01-01

109

High Efficiency Secondary Somatic Embryogenesis in Hovenia dulcis Thunb. through Solid and Liquid Cultures  

PubMed Central

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

Yang, Jingli; Wu, Songquan; Li, Chenghao

2013-01-01

110

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

PubMed

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

Yang, Jingli; Wu, Songquan; Li, Chenghao

2013-05-29

111

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

2011-09-17

112

Shoot regeneration and somatic embryogenesis from different explants of Brahmi [Bacopa monniera (L.) Wettst.  

Microsoft Academic Search

The morphogenetic potential of node, internode and leaf explants of Brahmi [Bacopa monniera (L.) Wettst.] was investigated to develop reliable protocols for shoot regeneration and somatic embryogenesis. The explants\\u000a were excised from shoots raised from axillary buds of nodal explants cultured on Murashige and Skoog (MS) basal medium. Presence\\u000a of 6-benzylaminopurine (BA) or kinetin influenced the degree of callus formation,

V. Tiwari; B. Deo Singh; K. Nath Tiwari

1998-01-01

113

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

Microsoft Academic Search

BackgroundThe 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 FindingsDevelopmental localization of pectic homogalacturonan

Chunxiang Xu; Lu Zhao; Xiao Pan; Jozef Šamaj

2011-01-01

114

Direct somatic embryogenesis and plant regeneration from leaf explants of Phalaenopsis amabilis  

Microsoft Academic Search

Leaf explants of Phalaenopsis amabilis var. formosa formed clusters of somatic embryos directly from epidermal cells without an intervening callus within 20 – 30 d when cultured\\u000a on 1\\/2-strength modified Murashige and Skoog medium supplemented with 0.1, 1 and 3 mg dm?3 TDZ. Repetitive production of embryos involved secondary embryogenesis could be obtained by culturing segments of embryogenic\\u000a masses on

J. T. Chen; W. C. Chang

2006-01-01

115

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

Microsoft Academic Search

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

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

2008-01-01

116

Somatic embryogenesis and plant regeneration from pistil thin cell layers of Citrus  

Microsoft Academic Search

Callus induction, somatic embryogenesis and plant regeneration were obtained in six different citrus species [Citrus deliciosa Ten. (cv 'Avana'), C.limon (L.) Burm. (cv 'Berna'), C.madurensis Lour. (cv 'CNR P9'), C.medica L. (cv 'Cedro di Trabia'), C.tardiva Hort. ex Tan. (cv 'CNR P6'), C.sinensis (L.) Osb. (cv 'Ugdulena 7')] from cultures of pistil transverse thin cell layer explants [(t)TCL]. Explants were

F. Carimi; F. De Pasquale; F. G. Crescimanno

1999-01-01

117

In vitro plant regeneration via somatic embryogenesis from root culture of some rhizomatous irises  

Microsoft Academic Search

A method for plant regeneration of Iris via somatic embryogenesis is described. Root and leaf pieces from in vitro-grown plants of several genotypes of rhizomatous Iris sp. were cultured in vitro. Callus induction occurred only on root cultures incubated under low light intensity (35 µmol m-2 s-1) on two induction media containing 2,4-D (4.5 or 22.5 µM), NAA (5.4 µM)

Genevičve Laublin; Hargurdeep S. Saini; Mario Cappadocia

1991-01-01

118

Factors influencing somatic embryogenesis induction in Eucalyptus globulus Labill.: basal medium and anti-browning agents  

Microsoft Academic Search

The low induction rates of somatic embryogenesis (SE) in Eucalyptus\\u000a globulus hamper scaling up the process for commercialization. We analyzed the effectiveness of several media (MS, 1\\/2MS, B5, WPM,\\u000a DKW and JADS) during SE induction and expression. MS and B5 were the best media for SE induction and embling regeneration.\\u000a In general, MS was the best medium for expression, independently

Gloria Pinto; Sónia Silva; Yill-Sung Park; Lucinda Neves; Clara Araújo; Conceiçăo Santos

2008-01-01

119

Reference gene selection for qPCR analysis during somatic embryogenesis in longan tree  

Microsoft Academic Search

Real-time reverse transcriptase PCR is a powerful tool to investigate relevant changes in gene expression during plant somatic embryogenesis (S.E.); however, this method lacks ideal reference genes. To select the most stable reference genes for S.E. studies, the expression profiles of seven frequently used reference genes (18S RNA, eIF-4a, UBQ, ACTB, EF-1a, Histone H3, and 2-TUB) and functional genes (Fe-SOD,

Y. L. Lin; Z. X. Lai

2010-01-01

120

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

121

Histology of early somatic embryogenesis inHevea brasiliensis: The importance of the timing of subculturing  

Microsoft Academic Search

Somatic embryos ofHevea brasiliensis can be obtained by culturing thin sections of inner tegument of seed on two successive different media, MH1 and MH3. Histological study showed that in calli cultured on non-renewed medium MH1 for 40 days, the embryogenesis process initiated on the 20th day did not produce results owing to early degeneration of the cells involved in the

Nicole Michaux-Ferričre; Marc-Philippe Carron

1989-01-01

122

Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASES1 and 2 Are Essential for Tapetum Development and Microspore Maturation  

Microsoft Academic Search

Among the >200 members of the leucine-rich repeat receptor kinase family in Arabidopsis thaliana, only a few have been functionally characterized. Here, we report a critical function in anther development for the SOMATIC EMBRYOGENESIS RECEPTOR KINASE1 (SERK1) and SERK2 genes. Both SERK1 and SERK2 are expressed widely in locules until stage 6 anthers and are more concentrated in the tapetal

Jean Colcombet; Aurelien Boisson-Dernier; Roc Ros-Palau; Carlos E. Vera; Julian I. Schroeder

2005-01-01

123

The effects of silver nitrate and different carbohydrate sources on somatic embryogenesis in Coffea canephora  

Microsoft Academic Search

The response of five Coffea canephora Pierre genotypes with regard to somatic embryogenesis was tested on media containing silver nitrate (AgNO3) and different carbohydrates (sucrose, fructose, maltose and glucose). The presence of AgNO3 caused only small modifications to the ionic equilibrium of the media. At concentrations between 30–60 µM, AgNO3 improved embryo yield for the genotypes evaluated, while higher doses

Sandra R. L. Fuentes; Maria B. P. Calheiros; Joăo Manetti-Filho; Luiz G. E. Vieira

2000-01-01

124

Effect of cold treatment on precocious germination in somatic embryogenesis of wheat (Triticum aestivum)  

Microsoft Academic Search

Immature embryos are the best explants for induction of somatic embryogenesis. However, precocious germination of these explants is a difficult problem facing this technology in certain wheat (Triticum aestivum L.) cultivars. To overcome this problem, spikes were harvested at 10–14 days post?anthesis, sterilised, and stored under two different conditions (4°C for 4, 7, and 10 days and 8°C for 4,

K. H. Kiarostami; H. Ebrahimzadeh

2001-01-01

125

Somatic embryogenesis and plant regeneration from shoot-tip explants in Phoenix dactylifera L  

Microsoft Academic Search

For maximum avoidance of somaclonal variation risks, the commonly used medium for somatic embryogenesis inPhoenix dactylifera has been lowered in growth regulators and activated charcoal. When initially cultured on MS basal medium containing only\\u000a 150 mg dm?3 charcoal, 5 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D) and 5 mg dm?3 benzylaminopurine (BAP), 10 to 20% of shoot-tip explants developed into embryogenic calli.

I. El Hadrami; R. Cheikh; M. Baaziz

1995-01-01

126

Induction of somatic embryogenesis and in vitro flowering from inflorescences of chamomile (Chamomilla recutita L.)  

Microsoft Academic Search

A protocol has been developed for the induction of somatic embryogenesis from flower explants of chamomile (Chamomilla recutita L.). The effects of several plant growth regulators [?-naphthylacetic acid (NAA), 2,4-dichlorophenoxyacetic acid, 6-benzyladenine (BA) and kinetin (Kin), alone or in combination]\\u000a and the flower type (disk or ray flower) were investigated. Both types of flowers responded to the callus and shoot

S. Kintzios; A. Michaelakis

1999-01-01

127

Shoot organogenesis and somatic embryogenesis from leaf and shoot explants of Ochna integerrima (Lour)  

Microsoft Academic Search

Ochna integerrima is a medicinal and ornamental plant in Southeastern Asia. It has been listed as a rare and endangered species in China. Here\\u000a we studied the effects of plant growth regulators and their concentrations on the induction of somatic embryogenesis and shoot\\u000a organogenesis from leaf and shoot explants of O. integerrima for the first time. Cytokinins played a crucial

Guohua Ma; Jinfeng Lü; Xinhua Zhang; Jietang Zhao

2011-01-01

128

Plant regeneration from protoplasts of Musa acuminata cv. Mas (AA) via somatic embryogenesis  

Microsoft Academic Search

A protocol for plant regeneration from protoplasts of Musa acuminata cv. Mas (AA) via somatic embryogenesis was developed. Viable protoplasts were isolated from embryogenic cell suspensions\\u000a at a yield of 1.2 × 107 protoplasts\\/ml packed cell volume (PCV). Liquid and feeder layer culture systems with medium-A and medium-B were used for\\u000a protoplast culture. In liquid culture system, medium-B was more efficient for

Wang Xiao; Xue-Lin Huang; Xia Huang; Ya-Ping Chen; Xue-Mei Dai; Jie-Tang Zhao

2007-01-01

129

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 ...

130

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

131

Somatic embryogenesis and ginsenoside production of Panax ginseng in phytohormone-free medium.  

PubMed

Embryogenic cultures of Panax ginseng were established without using phytohormones. Somatic embryos developed from the roots of an in vitro seedling and from excised leaf and petiole segments cultured in half-macro-salt strength Murashige and Skoog medium. Excised leaf and petiole segments were obtained from in vitro germinated seedlings. Plantlets were subsequently obtained from developing somatic embryos in phytohormone-free media. Shoot formation from somatic embryos was influenced by light intensity. The rate of growth and frequency of embryogenesis were improved when cut-up embryogenic tissues were inoculated into liquid media in the dark. The ginsenoside contents of a 4 year-old field-cultivated root, seedlings from zygotic embryos, somatic embryos and embryogenic tissues were determined and compared. Somatic embryos contained 1.7 times the amount of ginsenoside Rb1 and 2.3 times the amount of ginsenoside Re compared to seedlings from zygotic embryos. Ginsenoside Rd, which was absent in the seedlings derived from zygotic embryos, was detected in somatic embryos. Higher ginsenosides Rd and Rg1 levels were found in embryogenic tissues grown on solid media than in tissues grown in liquid media. The total ginsenoside yields, including the ginsenosides Rb1 and Rg1 levels, of cut-up embryogenic tissues, were higher than those of clump tissues. PMID:10859948

Shu, W; Yoshimatsu, K; Yamaguchi, H; Shimomura, K

1999-01-01

132

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

133

Efficient plant regeneration through somatic embryogenesis from callus cultures of Oncidium (Orchidaceae)  

Microsoft Academic Search

An efficient method was established for high frequency somatic embryogenesis and plant regeneration from callus cultures of a hybrid of sympodial orchid (Oncidium ‘Gower Ramsey’). Compact and yellow–white embryogenic calli formed from root tips and cut ends of stem and leaf segments on 1\\/2 MS [11] basal medium supplemented with 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ, 0.1–3 mg\\/l), 2,4-dichlorophenoxyacetic acid (2,4-D, 3–10 mg\\/l) and

Jen-Tsung Chen; Wei-Chin Chang

2000-01-01

134

Long-term study of somatic embryogenesis from anthers and ovaries of 12 grapevine ( Vitis sp.) genotypes  

Microsoft Academic Search

Summary  Anthers and ovaries of six grapevine cultivars (three Vitis vinifera L., two V Labruscana L. H. Bailey, and one complex hybrid) were extracted from flower buds over 2 yr and cultured on three media reported to promote\\u000a somatic embryogenesis in Vitis tissues. The highest percent embryogenesis from the hybrid ‘Chancellor’ and V. vinifera ‘Chardonnay’, ‘Merlot’, and ‘Pinot Noir’ occurred on

Julie R. Kikkert; Michael J. Striem; José R. Vidal; Patricia G. Wallace; John Barnard; Bruce I. Reisch

2005-01-01

135

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species  

PubMed Central

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets.

Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah

2012-01-01

136

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species.  

PubMed

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F(1) plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Azad, Md Abul Kalam; Rabbani, Md Golam; Amin, Latifah

2012-12-12

137

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

PubMed

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

Cai, Lin; Fu, Lin; Ji, Lianghui

2011-04-01

138

Histocytological Analysis of Callogenesis and Somatic Embryogenesis from Cell Suspensions of Date Palm (Phoenix dactylifera)  

PubMed Central

• Background and Aims The date palm is a dioecious perennial species of the Arecaceae for which in vitro micropropagation is essential to ensure the renewal of palm plantations. This study presents a histocytological analysis of the traditional Mauritanian Amsekhsi cultivar beginning from the initial callogenesis and continuing up to the establishment of the cellular embryogenic cell suspensions. The formation of somatic embryos and their development into rooted plants are also described. • Methods Foliar segments of seedlings cultured in the presence of 2,4-D produced primary calli that were chopped to produce fine friable granular calli that subsequently produced cellular suspensions when transferred to liquid medium. The somatic proembryos that developed after removal of the 2,4-D were plated on agar medium where they developed into rooted plants. Thin sections of tissue fragments taken at each stage of the process were stained using Periodic Acid Schiff and Naphthol Blue-Black. • Key Results The first cellular divisions were localized close to the vascular vessels of the leaf. The primary calli were obtained within 2 months. Fine friable granular calli grew quickly after the primary calli were chopped. Individual embryogenic cells were identified that rapidly started to divide and developed into globular proembryos. In addition, in the microcalli, breaking zones appeared in the thick pectocellulosic walls which delimited the pluricellular proembryos. The anatomy of somatic embryos is similar to that of zygotic embryos despite a deficit in the accumulation of intracellular proteins. When rooted with NAA, the vitroplants developed a strong orthotropic taproot. • Conclusions This study contributes to understanding the whole process of somatic embryogenesis, but two specific questions remain to be answered: what factors are involved in the reactivation of the somatic cells at the beginning of the initial callogenesis, and why do the somatic embryos not accumulate proteins in their tissues during maturation?

SANE, D.; ABERLENC-BERTOSSI, F.; GASSAMA-DIA, Y. K.; SAGNA, M.; TROUSLOT, M. F.; DUVAL, Y.; BORGEL, A.

2006-01-01

139

Calcium-Mediated Signaling during Sandalwood Somatic Embryogenesis. Role for Exogenous Calcium as Second Messenger1  

PubMed Central

The possible involvement of Ca2+-mediated signaling in the induction/regulation of somatic embryogenesis from pro-embryogenic cells of sandalwood (Santalum album) has been investigated. 45Ca2+-uptake studies and fura-2 fluorescence ratio photometry were used to measure changes in [Ca2+]cyt of pro-embryogenic cells in response to culture conditions conducive for embryo development. Sandalwood pro-embryogenic cell masses (PEMs) are obtained in the callus proliferation medium that contains the auxin 2,4-dichlorophenoxyacetic acid. Subculture of PEMs into the embryo differentiation medium, which lacks 2,4-dichlorophenoxyacetic acid and has higher osmoticum, results in a 4-fold higher 45Ca2+ incorporation into the symplast. Fura-2 ratiometric analysis corroboratively shows a 10- to 16-fold increase in the [Ca2+]cyt of PEMs, increasing from a resting concentration of 30 to 50 nm to 650 to 800 nm. Chelation of exogenous Ca2+ with ethyleneglycol-bis(aminoethyl ether)-N,N?-tetraacetic acid arrests such an elevation in [Ca2+]cyt. Exogenous Ca2+ when chelated or deprived also arrests embryo development and inhibits the accumulation of a sandalwood Ca2+-dependent protein kinase. However, such culture conditions do not cause cell death as the PEMs continue to proliferate to form larger cell clumps. Culture treatment with N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide reduced embryogenic frequency by 85%, indicating that blockage of Ca2+-mediated signaling pathway(s) involving sandalwood Ca2+-dependent protein kinase and/or calmodulin causes the inhibition of embryogenesis. The observations presented are evidence to suggest a second messenger role for exogenous Ca2+ during sandalwood somatic embryogenesis.

Anil, Veena S.; Rao, K. Sankara

2000-01-01

140

AGAMOUS-Like15 Promotes Somatic Embryogenesis in Arabidopsis and Soybean in Part by the Control of Ethylene Biosynthesis and Response1[C][W][OA  

PubMed Central

Many of the regulatory processes occurring during plant embryogenesis are still unknown. Relatively few cells are involved, and they are embedded within maternal tissues, making this developmental phase difficult to study. Somatic embryogenesis is a more accessible system, and many important regulatory genes appear to function similar to zygotic development, making somatic embryogenesis a valuable model for the study of zygotic processes. To better understand the role of the Arabidopsis (Arabidopsis thaliana) MADS factor AGAMOUS-Like15 (AGL15) in the promotion of somatic embryogenesis, direct target genes were identified by chromatin immunoprecipitation-tiling arrays and expression arrays. One potential directly up-regulated target was At5g61590, which encodes a member of the ethylene response factor subfamily B-3 of APETALA2/ETHYLENE RESPONSE FACTOR transcription factors and is related to Medicago truncatula SOMATIC EMBRYO-RELATED FACTOR1 (MtSERF1), which has been shown to be required for somatic embryogenesis in M. truncatula. Here, we report confirmation that At5g61590 is a directly expressed target of AGL15 and that At5g61590 is essential for AGL15’s promotion of somatic embryogenesis. Because At5g61590 is a member of the ETHYLENE RESPONSE FACTOR family, effects of ethylene on somatic embryogenesis were investigated. Precursors to ethylene stimulate somatic embryogenesis, whereas inhibitors of ethylene synthesis or perception reduce somatic embryogenesis. To extend findings to a crop plant, we investigated the effects of ethylene on somatic embryogenesis in soybean (Glycine max). Furthermore, we found that a potential ortholog of AGL15 in soybean (GmAGL15) up-regulates ethylene biosynthesis and response, including direct regulation of soybean orthologs of At5g61590/MtSERF1 named here GmSERF1 and GmSERF2, in concordance with the M. truncatula nomenclature.

Zheng, Qiaolin; Zheng, Yumei; Perry, Sharyn E.

2013-01-01

141

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

PubMed

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

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

2007-11-01

142

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

PubMed

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

Verma, Manju; Bansal, Y K

2012-12-01

143

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

144

Effective Organogenesis, Somatic Embryogenesis and Salt Tolerance Induction In Vitro in the Persian Lilac Tree (Melia azedarach L.)  

Microsoft Academic Search

An effective tissue culture system to regenerate Melia azedarach (Meliaceae), an important multipurpose - including ornamental value - tree, was established. The optimized protocol resulted in plant formation from cotyledon explants via organogenesis and somatic embryogenesis. Embryogenic callus induction occurred on full strength (salts and vitamins) MS medium containing 3 mg\\/L 1-naphthaleneacetic acid (NAA) and 1 mg\\/L 6-benzyladenine (BA) with

Sandra E. Sharry

145

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

146

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

147

Molecular mechanism for plant steroid receptor activation by somatic embryogenesis co-receptor kinases.  

PubMed

Brassinosteroids, which control plant growth and development, are sensed by the leucine-rich repeat (LRR) domain of the membrane receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1), but it is unknown how steroid binding at the cell surface activates the cytoplasmic kinase domain of the receptor. A family of somatic embryogenesis receptor kinases (SERKs) has been genetically implicated in mediating early brassinosteroid signaling events. We found a direct and steroid-dependent interaction between the BRI1 and SERK1 LRR domains by analysis of their complex crystal structure at 3.3 angstrom resolution. We show that the SERK1 LRR domain is involved in steroid sensing and, through receptor-co-receptor heteromerization, in the activation of the BRI1 signaling pathway. Our work reveals how known missense mutations in BRI1 and in SERKs modulate brassinosteroid signaling and the targeting mechanism of BRI1 receptor antagonists. PMID:23929946

Santiago, Julia; Henzler, Christine; Hothorn, Michael

2013-08-08

148

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

2010-02-10

149

Enhancement of somatic embryogenesis in camphor tree ( Cinnamomum camphora L.): osmotic stress and other factors affecting somatic embryo formation on hormone-free medium  

Microsoft Academic Search

The aim of this study was to improve the direct somatic embryogenesis and initiate embryogenic callus formation in camphor\\u000a tree (Cinnamomum camphora L.) on hormone-free medium. The influence of osmotic stress pretreatment of immature zygotic embryos (0.5 and 1.0 M solution\\u000a of sucrose for 12, 24, 48, 72, 96, 120, and 144 h at 4 or 25°C) before cultured on hormone-free medium,

Xueping Shi; Xigang Dai; Guofeng Liu; Manzhu Bao

2009-01-01

150

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

Microsoft Academic Search

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

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

2002-01-01

151

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

152

Somatic embryogenesis in sawara cypress ( Chamaecyparis pisifera Sieb. et Zucc.) for stable and efficient plant regeneration, propagation and protoplast culture  

Microsoft Academic Search

Somatic embryogenesis inChamaecyparis pisifera was initiated from immature seeds collected from the end of June to early July. We obtained initiation frequencies ranging\\u000a from 12.5 to 33.3% using whole seed explants in liquid media. Embryogenic cultures were maintained and proliferated for more\\u000a than a year in solid and liquid media. High maturation frequencies of ‘high quality’ embryos were obtained on

Emilio Maruyama; Yoshihisa Hosoi; Katsuaki Ishii

2002-01-01

153

Rice SERK1 gene positively regulates somatic embryogenesis of cultured cell and host defense response against fungal infection  

Microsoft Academic Search

Here we report on the isolation and characterization of a somatic embryogenesis receptor-like kinase (OsSERK1) gene in rice (Oryza sativa). The OsSERK1 gene belongs to a small subfamily of receptor-like kinase genes in rice and shares a highly conserved gene structure and extensive sequence homology with previously reported plant SERK genes. Though it has a basal level of expression in

H. Hu; L. Xiong; Y. Yang

2005-01-01

154

Somatic embryogenesis in saffron ( Crocus sativus L.). Histological differentiation and implication of some components of the antioxidant enzymatic system  

Microsoft Academic Search

The ontogenetic developmental stages of saffron somatic embryogenesis have been studied and characterized using light microscopy\\u000a and the biochemical determination of the antioxidant enzymatic system. The embryogenic callus underwent internal segmented\\u000a divisions with the formation of globular embryos that were attached to the callus surface by a broad multicellular structure.\\u000a Further development of the embryoids was characterized by the emergence

Silvia Blazquez; Enrique Olmos; José Antonio Hernández; Nieves Fernández-García; José Antonio Fernández; Abel Piqueras

2009-01-01

155

Somatic embryogenesis in pearl millet (Pennisetum glaucum): Strategies to reduce genotype limitation and to maintain long-term totipotency  

Microsoft Academic Search

Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somatic embryogenesis and regeneration.\\u000a Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were\\u000a used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison\\u000a with immature zygotic embryos. Moreover, differences

Pascal Lambé; Hity S. N. Mutambel; Roger Deltour; Monique Dinant

1998-01-01

156

Regeneration of soybean ( Glycine max L. Merrill) through direct somatic embryogenesis from the immature embryonic shoot tip  

Microsoft Academic Search

We describe here a simple and efficient system of soybean (Glycine max L. Merrill) regeneration through direct somatic embryogenesis by using immature embryonic shoot tips (IEST) as explants.\\u000a The cultivar Kaohsiung 10 (cv. K10) used in this study did not show embryogenic response either from mature seed-derived explants\\u000a (cotyledon, embryonic tip, leaf, shoot and root) or immature cotyledons. However, it

Murugan Loganathan; Subbiyan Maruthasalam; Ling Yin Shiu; Wei Ching Lien; Wen Hwei Hsu; Pei Fang Lee; Chih Wen Yu; Chin Ho Lin

2010-01-01

157

In vitro plant regeneration through somatic embryogenesis and direct shoot organogenesis in Pennisetum glaucum (L.) R. Br  

Microsoft Academic Search

An efficient in vitro plant regeneration protocol through somatic embryogenesis and direct shoot organogenesis has been developed for pearl millet\\u000a (Pennisetum glaucum). Efficient plant regeneration is a prerequisite for a complete genetic transformation protocol. Shoot tips, immature inflorescences,\\u000a and seeds of two genotypes (843B and 7042-DMR) of pearl millet formed callus when cultured on Murashige and Skoog (MS) medium\\u000a supplemented

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

2009-01-01

158

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

159

Plant regeneration from protoplasts of dessert banana cv. Grande Naine ( Musa spp., Cavendish sub-group AAA) via somatic embryogenesis  

Microsoft Academic Search

Protoplast culture and plant regeneration of the dessert banana cultivar Grande Naine (Musa spp., Cavendish sub-group AAA) were achieved through somatic embryogenesis. Protoplasts were isolated from cell suspensions at a yield of 3쎻 protoplasts\\/ml packed cell volume (0.5 g). For the induction of cell divisions, two banana cell suspensions, SF265 (AA) and IRFA903 (AA), were used as feeder layers. SF265

A. Assani; R. Haicour; G. Wenzel; F. Côte; F. Bakry; B. Foroughi-Wehr; G. Ducreux; M.-E. Aguillar; A. Grapin

2001-01-01

160

Somatic embryogenesis and plant regeneration from cotyledon explants of a timber-yielding leguminous tree, Dalbergia sissoo Roxb.  

PubMed

Efficient plant regeneration through somatic embryogenesis was achieved from callus cultures derived from semi-mature cotyledon explants of Dalbergia sissoo Roxb., a timber-yielding leguminous tree. Somatic embryos developed over the surface of embryogenic callus and occasionally, directly from cotyledon explants without intervening callus phase. Callus cultures were initiated from cotyledon pieces of D. sissoo on Murashige and Skoog (1962) medium supplemented with 4.52, 9.04, 13.57, and 18.09 mumol/L 2,4-dichlorophenoxyacetic acid and 0.46 mumol/L Kinetin. Maximum percentage response for callus formation was 89% on MS medium supplemented with 9.04 mumol/L 2,4-D' and 0.46 mumol/L Kn. Somatic embryogenesis was achieved after transfer of embryogenic callus clumps to 1/2-MS medium without plant growth regulators (1/2-MSO). Average numbers of somatic embryos per callus clump was 26.5 on 1/2-MSO medium after 15 weeks of culture. Addition of 0.68 mmol/L L-glutamine to 1/2-MSO medium enhanced somatic embryogenesis frequency from 55% to 66% and the number of somatic embryos per callus clump from 26.5 to 31.1. Histological studies were carried out to observe various developmental stages of somatic embryos. About 50% of somatic embryos converted into plantlets on 1/2-MSO medium containing 2% sucrose, after 20 days of culture. Transfer of somatic embryos to 1/29-MSO medium containing 10% sucrose for 15 days prior to transfer on 1/2-MS medium with 2% sucrose enhanced the conversion of somatic embryos into plantlets from 50 to 75%. The plantlets with shoots and roots were transferred to 1/2 and 1/4-liquid MS medium, each for 10 days, and then to plastic pots containing autoclaved peat moss and compost mixture (1:1). 70% of the plantiets survived after 10 weeks of transfer to pots. 120 regenerated plantlets out of 150 were successfully acclimatised. After successful acclimatisation, plants were transferred to earthen pots. PMID:12756922

Singh, Ajay Kumar; Chand, Suresh

2003-04-01

161

The effect of TDZ on organogenesis and somatic embryogenesis in pigeonpea ( Cajanus cajan L. Millsp)  

Microsoft Academic Search

The effect of TDZ was studied on seedlings of pigeonpea. Seedlings raised from decoated seeds on MS basal medium supplemented with a low concentration of TDZ (0.05–1.0 ?M) induced multiple shoots, and an intermediary concentration (5.0 ?M) produced clusters of leafy structures, and a higher concentration (10.0 or 20.0 ?M) completely switched the regeneration pathway by inducing somatic embryos at

N. Dolendro Singh; Lingaraj Sahoo; Neera Bhalla Sarin; Pawan K Jaiwal

2003-01-01

162

Transcript profiling reveals complex auxin signalling pathway and transcription regulation involved in dedifferentiation and redifferentiation during somatic embryogenesis in cotton  

PubMed Central

Background Somatic embryogenesis (SE), by which somatic cells of higher plants can dedifferentiate and reorganize into new plants, is a notable illustration of cell totipotency. However, the precise molecular mechanisms regulating SE remain unclear. To characterize the molecular events of this unique process, transcriptome analysis, in combination with biochemical and histological approaches, were conducted in cotton, a typical plant species in SE. Genome-wide profiling of gene expression allowed the identification of novel molecular markers characteristic of this developmental process. Results RNA-Seq was used to identify 5,076 differentially expressed genes during cotton SE. Expression profile and functional assignments of these genes indicated significant transcriptional complexity during this process, associated with morphological, histological changes and endogenous indole-3-acetic acid (IAA) alteration. Bioinformatics analysis showed that the genes were enriched for basic processes such as metabolic pathways and biosynthesis of secondary metabolites. Unigenes were abundant for the functions of protein binding and hydrolase activity. Transcription factor–encoding genes were found to be differentially regulated during SE. The complex pathways of auxin abundance, transport and response with differentially regulated genes revealed that the auxin-related transcripts belonged to IAA biosynthesis, indole-3-butyric acid (IBA) metabolism, IAA conjugate metabolism, auxin transport, auxin-responsive protein/indoleacetic acid-induced protein (Aux/IAA), auxin response factor (ARF), small auxin-up RNA (SAUR), Aux/IAA degradation, and other auxin-related proteins, which allow an intricate system of auxin utilization to achieve multiple purposes in SE. Quantitative real-time PCR (qRT-PCR) was performed on selected genes with different expression patterns and functional assignments were made to demonstrate the utility of RNA-Seq for gene expression profiles during cotton SE. Conclusion We report here the first comprehensive analysis of transcriptome dynamics that may serve as a gene expression profile blueprint in cotton SE. Our main goal was to adapt the RNA-Seq technology to this notable development process and to analyse the gene expression profile. Complex auxin signalling pathway and transcription regulation were highlighted. Together with biochemical and histological approaches, this study provides comprehensive gene expression data sets for cotton SE that serve as an important platform resource for further functional studies in plant embryogenesis.

2012-01-01

163

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

PubMed

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 x C. endivia L. var. latifolia). In order to learn more about the involvement of this enzyme in this process, in situ-hybridization as well as immunolocalization were performed in parallel. GST-mRNAs and proteins were colocalized in small veins, particularly in young protoxylem cell walls. During cell reactivation, the in situ and protein signals became less intense and were associated with chloroplasts. The GST-mRNAs and corresponding proteins were not always colocalized in the same tissues. While high amounts of transcripts could be detected in multicellular embryos, the proteins were not well labeled. Our results indicated that GSTs belong to a complex anti-oxidant mechanism within the cell, and also at the cell wall level. GSTs presence in reactivated cell and multicellular embryos is discussed in relation to redox cell status. PMID:19516999

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

2007-09-01

164

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

165

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

Microsoft Academic Search

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

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

2008-01-01

166

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

167

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

Microsoft Academic Search

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

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

2008-01-01

168

[Calcium-dependent mechanism of somatic embryogenesis in oncogene rolC expressing cell cultures of Panax ginseng].  

PubMed

It was shown earlier, that ginseng embryogenic cell culture 2c3 was obtained as a result of callus cells transformation with the Agrobacterium rhizogenes rolC oncogene. In the present report we determine that inhibitors of Ca2+-channels (LaCl3, verapamil, niflumic acid) certainly lowered the quantity of somatic embryos in the 2c3 cell culture. This is the evidence of the influence of calcium-dependent signal system on plant embryogenesis. Protein kinases inhibitors W7 and H7 also caused the lowering of somatic embryos quantity in the 2c3 cell culture. We analysed changes of CDPK genes expression in embryogenic 2c3 cell culture. Total expression decreased 1.2-1.5 times comparing with the control callus culture. CDPK expression in the 2c3 embryogenic culture lowered by the inhibition of expression of the gene subfamilies PgCDPK1 (PgCDPK1a and PgCDPK1b) and PgCDPK3 (PgCDPK3a). At the same time, expression of PgCDPK2 gene subfamily (PgCDPK2b and PgCDPK2d) was increased. We suppose that genes of PgCDPK2 subfamily might be responsible for the embryogenesis initiation in the 2c3 ginseng cell culture. It was shown for the first time that the rolC gene and the process of embryogenesis could change expression of particular forms of CDPK genes. PMID:18610836

Kiselev, K V; Gorpenchenko, T Iu; Chernoded, G K; Dubrovina, A S; Grishchenko, O V; Bulgakov, V P; Zhuravlev, Iu N

169

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.

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

2013-01-01

170

Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid signaling.  

PubMed

The Arabidopsis thaliana somatic embryogenesis receptor kinases (SERKs) consist of five members, SERK1 to SERK5, of the leucine-rich repeat receptor-like kinase subfamily II (LRR-RLK II). SERK3 was named BRI1-Associated Receptor Kinase 1 (BAK1) due to its direct interaction with the brassinosteroid (BR) receptor BRI1 in vivo, while SERK4 has also been designated as BAK1-Like 1 (BKK1) for its functionally redundant role with BAK1. Here we provide genetic and biochemical evidence to demonstrate that SERKs are absolutely required for early steps in BR signaling. Overexpression of four of the five SERKs-SERK1, SERK2, SERK3/BAK1, and SERK4/BKK1-suppressed the phenotypes of an intermediate BRI1 mutant, bri1-5. Overexpression of the kinase-dead versions of these four genes in the bri1-5 background, on the other hand, resulted in typical dominant negative phenotypes, resembling those of null BRI1 mutants. We isolated and generated single, double, triple, and quadruple mutants and analyzed their phenotypes in detail. While the quadruple mutant is embryo-lethal, the serk1 bak1 bkk1 triple null mutant exhibits an extreme de-etiolated phenotype similar to a null bri1 mutant. While overexpression of BRI1 can drastically increase hypocotyl growth of wild-type plants, overexpression of BRI1 does not alter hypocotyl growth of the serk1 bak1 bkk1 triple mutant. Biochemical analysis indicated that the phosphorylation level of BRI1 in serk1 bak1 bkk1 is incapable of sensing exogenously applied BR. As a result, the unphosphorylated level of BES1 has lost its sensitivity to the BR treatment in the triple mutant, indicating that the BR signaling pathway has been completely abolished in the triple mutant. These data clearly demonstrate that SERKs are essential to the early events of BR signaling. PMID:22253607

Gou, Xiaoping; Yin, Hongju; He, Kai; Du, Junbo; Yi, Jing; Xu, Shengbao; Lin, Honghui; Clouse, Steven D; Li, Jia

2012-01-12

171

Genetic Evidence for an Indispensable Role of Somatic Embryogenesis Receptor Kinases in Brassinosteroid Signaling  

PubMed Central

The Arabidopsis thaliana Somatic Embryogenesis Receptor Kinases (SERKs) consist of five members, SERK1 to SERK5, of the leucine-rich repeat receptor-like kinase subfamily II (LRR-RLK II). SERK3 was named BRI1-Associated Receptor Kinase 1 (BAK1) due to its direct interaction with the brassinosteroid (BR) receptor BRI1 in vivo, while SERK4 has also been designated as BAK1-Like 1 (BKK1) for its functionally redundant role with BAK1. Here we provide genetic and biochemical evidence to demonstrate that SERKs are absolutely required for early steps in BR signaling. Overexpression of four of the five SERKs—SERK1, SERK2, SERK3/BAK1, and SERK4/BKK1—suppressed the phenotypes of an intermediate BRI1 mutant, bri1-5. Overexpression of the kinase-dead versions of these four genes in the bri1-5 background, on the other hand, resulted in typical dominant negative phenotypes, resembling those of null BRI1 mutants. We isolated and generated single, double, triple, and quadruple mutants and analyzed their phenotypes in detail. While the quadruple mutant is embryo-lethal, the serk1 bak1 bkk1 triple null mutant exhibits an extreme de-etiolated phenotype similar to a null bri1 mutant. While overexpression of BRI1 can drastically increase hypocotyl growth of wild-type plants, overexpression of BRI1 does not alter hypocotyl growth of the serk1 bak1 bkk1 triple mutant. Biochemical analysis indicated that the phosphorylation level of BRI1 in serk1 bak1 bkk1 is incapable of sensing exogenously applied BR. As a result, the unphosphorylated level of BES1 has lost its sensitivity to the BR treatment in the triple mutant, indicating that the BR signaling pathway has been completely abolished in the triple mutant. These data clearly demonstrate that SERKs are essential to the early events of BR signaling.

Du, Junbo; Yi, Jing; Xu, Shengbao; Lin, Honghui; Clouse, Steven D.; Li, Jia

2012-01-01

172

Plant regeneration via somatic embryogenesis in Styrian pumpkin: cytological and biochemical investigations  

Microsoft Academic Search

Somatic embryo formation was induced from cotyledon explants of Styrian pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) by using a solid MS medium supplemented with 16.11?µM NAA and 4.44?µM BA or 26.85?µM NAA and 13.32?µM BA. The callus proliferation was more efficient on medium supplemented with 26.85?µM NAA and 13.32?µM BA. In contrast, the embryogenic response was higher

A. Urbanek; B. Zechmann; M. Müller

2005-01-01

173

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

Microsoft Academic Search

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

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

1982-01-01

174

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

175

Growth regulators affect primary and secondary somatic embryogenesis in Madagaskar periwinkle ( Catharanthus roseus (L.) G. Don) at morphological and biochemical levels  

Microsoft Academic Search

An efficient somatic embryogenesis system has been established in Catharanthus roseus (L.) G. Don in which primary and secondary embryogenic calluses were developed from hypocotyls and primary cotyledonary somatic\\u000a embryos (PCSEs), respectively. Two types of calluses were different in morphology and growth behaviour. Hypocotyl-derived\\u000a embryogenic callus (HEC) was friable and fast-growing, while secondary callus derived from PCSE was compact and

A. Junaid; A. Mujib; M. P. Sharma; Wei Tang

2007-01-01

176

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

Microsoft Academic Search

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

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

2011-01-01

177

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.

2011-01-01

178

Imaging of polarity during zygotic and somatic embryogenesis of carrot (Daucus carota L.)  

Microsoft Academic Search

In this thesis a study of the regulation of coordinated growth and the development of polarity during embryogenesis of carrot, Daucus carota L., is described. To this end, several microscopical techniques were used, such as light microscopy, fluorescence microscopy, confocal scanning laser microscopy and electron microscopy. Next to this, immunocytochemical methods were used frequently to localize proteins in plant tissue

A. C. J. Timmers

1993-01-01

179

A comparative analysis of the development and quality of nursery plants derived from somatic embryogenesis and from seedlings for large-scale propagation of coffee ( Coffea arabica L . )  

Microsoft Academic Search

Plants of Coffea arabica L. derived via somatic embryogenesis, namely, somaclones, were evaluated with C. arabica seedlings grown in the nursery. At the time of their transfer to the nursery, somaclones of C. arabica cvs. Caturra and Costa Rica 95 (Catimor) were smaller and less vigorous than seedlings of the same cultivars. Following an\\u000a initial slow growth for a period

Andrea Menéndez-Yuffá; Dominique Barry-Etienne; Benoît Bertrand; Frédéric Georget; Hervé Etienne

2010-01-01

180

Influence of a loblolly pine ( Pinus taeda L.). Culture medium and its components on growth and somatic embryogenesis of the wild carrot ( Daucus carota L.)  

Microsoft Academic Search

A new culture medium, originally designed and shown to grow cell suspensions from a variety of loblolly pine (Pinus taeda L.) explants, was used to study growth and somatic embryogenesis of the wild carrot (Daucus carota L.) in cell suspensions. The new loblolly pine medium (LM) differed from the standard wild carrot medium (WCM) in having very low Ca2+, very

John D. Litvay; Devi C. Verma; Morris A. Johnson

1985-01-01

181

Clonal propagation of hybrid sweetgum ( Liquidambar styraciflua × L. formosana ) by somatic embryogenesis  

Microsoft Academic Search

Cultures were initiated from immature seeds derived from controlled pollinations between two sweetgum species (Liquidambar styraciflua and L. formosana) cultured on two induction media supplemented with 2,4-dichlorophenoxyacetic acid. Repetitive embryogenic cultures capable of producing somatic seedlings were obtained from 2% of the 1,020 seeds cultured, representing nine crosses between L. styraciflua and L. formosana. Hybrid genotypes of somatic seedlings were

W. A. Vendrame; C. P. Holliday; S. A. Merkle

2001-01-01

182

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

Microsoft Academic Search

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

Paula P. Chee; David M. Tricoli

1988-01-01

183

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.

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

2001-01-01

184

Transcriptome analysis during somatic embryogenesis of the tropical monocot Elaeis guineensis: evidence for conserved gene functions in early development.  

PubMed

With the aim of understanding the molecular mechanisms underlying somatic embryogenesis (SE) in oil palm, we examined transcriptome changes that occur when embryogenic suspension cells are initiated to develop somatic embryos. Two reciprocal suppression subtractive hybridization (SSH) libraries were constructed from oil palm embryogenic cell suspensions: one in which embryo development was blocked by the presence of the synthetic auxin analogue 2,4-dichlorophenoxyacetic acid (2,4-D: ) in the medium (proliferation library); and another in which cells were stimulated to form embryos by the removal of 2,4-D: from the medium (initiation library). A total of 1867 Expressed Sequence Tags (ESTs) consisting of 1567 potential unigenes were assembled from the two libraries. Functional annotation indicated that 928 of the ESTs correspond to proteins that have either no similarity to sequences in public databases or are of unknown function. Gene Ontology (GO) terms assigned to the two EST populations give clues to the underlying molecular functions, biological processes and cellular components involved in the initiation of embryo development. Macroarrays were used for transcript profiling the ESTs during SE. Hierarchical cluster analysis of differential transcript accumulation revealed 4 distinct profiles containing a total of 192 statistically significant developmentally regulated transcripts. Similarities and differences between the global results obtained with in vitro systems from dicots, monocots and gymnosperms will be discussed. PMID:19199047

Lin, Hsiang-Chun; Morcillo, Fabienne; Dussert, Stéphane; Tranchant-Dubreuil, Christine; Tregear, James W; Tranbarger, Timothy John

2009-02-07

185

Ontogenic variations in free and esterified fatty acids during somatic embryogenesis of flax ( Linum usitatissimum L.)  

Microsoft Academic Search

In vitro cultures of flax (Linum usitatissimum L.) were established on MS medium and four samplings were made during the 7 weeks of culture. The samples varied from the original hypocotyl segments (HS) at t0 and segments with incipient calli formation (HSC) after 2 weeks (t2), to embryogenic calli (EC), non-embryogenic calli (NEC) and somatic embryos (SE) collected after 5

Ana C. Cunha; Manuel Fernandes-Ferreira

2003-01-01

186

Involvement of ethylene in somatic embryogenesis in Scots pine ( Pinus sylvestris L.)  

Microsoft Academic Search

The involvement of the plant growth regulator ethylene in somatic embryo maturation of Pinus sylvestris (L.) was investigated. Genes that encoded 1-aminocyclopropane-1-carboxylate synthase (ACS), the rate-limiting enzyme in the\\u000a ethylene biosynthesis pathway, were isolated and characterized. Two novel complementary DNAs (cDNAs) of PsACS1 and PsACS2 that encode ACS were isolated from embryogenic cultures (ECs) along with their polymerase chain reaction

Jinrong Lu; Jorma Vahala; Ari Pappinen

187

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

188

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

2004-11-16

189

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

PubMed

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

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

1987-05-01

190

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

PubMed

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

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

2012-07-01

191

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

Microsoft Academic Search

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

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

2008-01-01

192

Callus induction, somatic embryogenesis and organogenesis in Narcissus confusus: correlation between the state of differentiation and the content of galanthamine and related alkaloids  

Microsoft Academic Search

In vitro cultures from two strains of Narcissus confusus (Amaryllidaceae) initiated from mature seeds were screened for their ability to produce alkaloids. Protocols for callus induction,\\u000a somatic embryogenesis and organogenesis were established. The alkaloid contents were determined by HPLC. Undifferentiated\\u000a calli produced small amounts of galanthamine, which increased with the degree of tissue differentiation. Scanning electron\\u000a micrographs of the cultures

M. Sellés; F. Viladomat; J. Bastida; C. Codina

1999-01-01

193

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

194

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

Microsoft Academic Search

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

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

2000-01-01

195

High frequency plant-regeneration through direct shoot development and somatic embryogenesis from immature inflorescence cultures of finger millet ( Eleusine coracana Gaertn)  

Microsoft Academic Search

Plant regeneration from cultured immature inflorescence segments of Eleusine coracana was obtained by direct shoot development and somatic embryogenesis. Direct development of shoots from cultured inflorescence segments occurred on MS medium supplemented with 2,4-D in combination with zeatin. Inflorescences with well developed spikelets differentiated at a low frequency (<5%) from callus cultures initiated on media supplemented with 2,4-D in combination

Leela George; Susan Eapen

1990-01-01

196

Endochitinase and ?-1,3-glucanase genes are developmentally regulated during somatic embryogenesis in Picea glauca  

Microsoft Academic Search

Two cDNAs isolated from white spruce [Picea glauca (Moench) Voss] somatic embryos, are predicted to encode a basic class IV chitinase and a ß-1,3-glucanase, respectively corresponding to genesPgChi-1 andPgGlu-1. Each represents a multigene family in spruce. Transcripts homologous toPgChi-1 orPgGlu-1 genes were highly abundant in embryogenic tissues and gradually decreased after tissues were placed on abscisic acid-containing maturation medium, with

Jin-Zhuo Dong; David I. Dunstan

1997-01-01

197

Auxin-orientation effects on somatic embryogenesis from immature soybean cotyledons  

Microsoft Academic Search

Summary  Development of somatic embryos of soybeanGlycine max (L.) Merr. has been studied using cultivars J103 and McCall and five auxin-sucrose treatment: naphthalene acetic acid at\\u000a 10 mg\\/liter with 1.5% sucrose (N10); 2,4-dichlorophenoxyacetic acid (2,4-D) at 0.25, 0.5 or 1.0 mg\\/liter with 1.5% sucrose\\u000a (D.25, D.5 D1); and 2,4-D at 25 mg\\/liter with 3% sucrose (D25). Cotyledons were excised aseptically from

L. M. Hartweck; P. A. Lazzeri; D. Cui; G. B. Collins; E. G. Williams

1988-01-01

198

Transcriptome profiling reveals auxin and cytokinin regulating somatic embryogenesis in different sister lines of cotton cultivar CCRI24.  

PubMed

To get a broader view on the molecular mechanisms underlying somatic embryogenesis (SE) in cotton (Gossypium hirsutum L.), global analysis of cotton transcriptome dynamics during SE in different sister lines was performed using RNA-Seq. A total of 204?349 unigenes were detected by de novo assembly of the 214?977?462 Illumina reads. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurements were positively correlated with the RNA-Seq results for almost all the tested genes (R(2) ?=?0.841, correlation was significant at the 0.01 level). Different phytohormone (auxin and cytokinin) concentration ratios in medium and the endogenous content changes of these two phytohormones at two stages in different sister lines suggested the roles of auxin and cytokinin during cotton SE. On the basis of global gene regulation of phytohormone-related genes, numerous genes from all the differentially expressed transcripts were involved in auxin and cytokinin biosynthesis and signal transduction pathways. Analyses of differentially expressed genes that were involved in these pathways revealed the substantial changes in gene type and abundance between two sister lines. Isolation, cloning and silencing/overexpressing the genes that revealed remarkable up- or down-expression during cotton SE were important. Furthermore, auxin and cytokinin play a primary role in SE, but potential cross-talk with each other or other factors remains unclear. PMID:23710882

Xu, Zhenzhen; Zhang, Chaojun; Zhang, Xueyan; Liu, Chuanliang; Wu, Zhixia; Yang, Zuoren; Zhou, Kehai; Yang, Xiaojie; Li, Fuguang

2013-07-01

199

Somatic embryogenesis and plant regeneration from protoplast culture of Crocus pallasii subsp. haussknechtii.  

PubMed

A protocol has been developed for plant regeneration from protoplast culture of Crocus pallasii subsp. haussknechtii using regenerable embryogenic calli obtained from shoot meristem culture on MS+9.28 microM kinetin+4.52 microM 2,4-D. Protoplasts were isolated directly from embryogenic calli, embedded in Ca-alginate beads and cultured with nurse cells in MS+4.64 microM kinetin+4.52 microM 2,4-D+5.68 microM ascorbic acid+0.3 M mannitol at 20 +/- 2 degrees C in darkness. After appearing ofmicrocalli on the surface of the beads, they were transferred onto 1/2MS+2.32 microM kinetin+2.26 microM 2,4-D+5.68 microM ascorbic acid for growth of embryogenic calli. Somatic embryos matured on MS medium growth regulator free and germinated on 1/2MS+14.45 microM GA3 +4.43 microM BA at 20 +/- 2 degrees C in a 16/8 h light/dark cycle. PMID:19069554

Karamian, Roya

2007-02-15

200

Highly-efficient somatic embryogenesis from cell suspension cultures of phalaenopsis orchids by adjusting carbohydrate sources  

Microsoft Academic Search

Summary  The influences of various carbohydrate sources, dried yeast (DY), and 6-benzylaminopurine (BA) were estimated on growth and\\u000a development of shoot tip-derived suspension cells of phalaenopsis orchid. Among the carbohydrates tested on Doriataenopsis cultured on gelled medium, glucose at 58.4 mM gave the highest efficiency of protocorm-like body (PLB) formation. Maltose and sorbitol only induced PLB formation without\\u000a callus proliferation. Sucrose

Ken Tokuhara; Masahiro Mii

2003-01-01

201

Expression analysis of somatic embryogenesis-related SERK, LEC1, VP1 and NiR ortologues in rye (Secale cereale L.)  

PubMed Central

The genetic basis of the regeneration process in cultured immature embryos of rye (Secale cereale L.) was analyzed. The experiments were designed to reveal differences between the in vitro culture responses of two inbred lines: L318 (a high regeneration ability) and L9 (a low potential for regeneration). The rye ortologues of plant genes previously recognized as crucial for somatic embryogenesis and morphogenesis in vitro were identified. Using oligonucleotide primers designed to conserved regions of the genes Somatic Embryogenesis Receptor-like Kinase (SERK), Leafy Cotyledon 1 (LEC1), Viviparous 1 (VP1) and NiR (encoding ferredoxin-nitrite reductase), it was possible to amplify specific homologous sequences from rye RNA by RT-PCR. The transcript levels of these genes were then measured during the in vitro culture of zygotic embryos, and the sites of expression localized. The expression profiles of these genes indicate that their function is likely to be correlated with the in vitro response of rye. In line L9, increased expression of the rye SERK ortologue was observed at most stages during the culture of immature embryos. The suppression of ScSERK expression appears to start after the induction of somatic embryogenesis and lasts up to plant regeneration. The rye ortologues of the LEC1 and VP1 genes may function in a complimentary manner and have a negative effect on the production of the embryogenic callus. The expression of the rye NiR ortologue during in vitro culture reveals its importance in the process of plant regeneration.

Rakoczy-Trojanowska, M.

2011-01-01

202

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

203

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.

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

2013-01-01

204

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

2009-08-21

205

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.

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

2007-01-01

206

Effects of genotype, light regime, explant position and orientation on direct somatic embryogenesis from leaf explants of Phalaenopsis orchids  

Microsoft Academic Search

The influence of light regime, explant position and orientation on direct embryo formation from leaf explants of two Phalaenopsis, P. amabilis and P. Nebula, were investigated to optimize the protocol for regenerating of this orchid. When explants were cultured in light,\\u000a direct embryogenesis was retarded in both species. Embryos showed whitish to pale green in color and larger size than

Wee-Peng Gow; Jen-Tsung Chen; Wei-Chin Chang

2009-01-01

207

Organization of initial stages of somatic embryogenesis in tissue culture of Citrus sinensis cv. Tarocco at the organismal level  

Microsoft Academic Search

Four-step protocol was established for the in vitro regeneration of Citrus sinensis cv. Tarocco somatic embryos that were morphologically similar to small somatic embryos in vivo. The regeneration procedure\\u000a comprises a mechanical destruction of embryogenic culture to obtain proembryogenic cell masses (PEMs) (step 1) followed by\\u000a culturing on three different media (steps 2–4). The approach developed allows in vitro simulating

N. A. Moiseeva; V. N. Serebryakova; L. Nardi; S. Lucretti; R. G. Butenko

2006-01-01

208

Somatic Embryogenesis or Shoot Formation Following High 2,4-D Pulse-Treatment of Mature Embryos of Paspalum scrobiculatum  

Microsoft Academic Search

Mature zygotic embryos of Paspalum scrobiculatum L. cv. PSC 1 on MS or N6 nutrient medium supplemented with various concentrations of 2,4-D (4.5 – 22.5 µM) formed embryogenic callus, which differentiated\\u000a into somatic embryos within 5 weeks of culture. The somatic embryos after transfer to hormone-free regeneration medium germinated\\u000a and formed plantlets. Of the two nutrient formulations, N6 was relatively

Vikrant; A. Rashid

2003-01-01

209

An efficient leaf-disc culture method for the regeneration via somatic embryogenesis and transformation of grape ( Vitis vinifera L.)  

Microsoft Academic Search

By manipulating hormone levels, light intensities and temperature, we have developed an efficient leaf-disc method for the regeneration of plants via embryogenesis and for transformation in four genotypes of Vitis vinifera L. In MS basal medium supplemented with 1 mg l-1 6-benzylaminopurine (BAP) and 0.1 mg l-1 2,4-dichlorophenoxyacetic acid, leaf discs cultured for 2 weeks under dark conditions produced calli

D. K. Das; M. K. Reddy; K. C. Upadhyaya; S. K. Sopory

2002-01-01

210

Variation of nuclear DNA content during somatic embryogenesis and plant regeneration of Coffea arabica L. using cytophotometry  

Microsoft Academic Search

Cytophotometric analysis of nuclear DNA was carried out in leaves of Coffea arabica L. plants grown in vitro. They were maintained for more than 1 year on MS media containing 0.53 ?M NAA, and 2.32 ?M kinetin, and embryogenic calli and somatic embryos were derived from them. Four suspension cultures of C. arabica differing in their embryogenic potential were also

Svetlana E Zoriniants; Alexander V Nosov; Miriam Monforte-Gonzalez; Marcela Mendes-Zeel; Victor M Loyola-Vargas

2003-01-01

211

Influence of phytohormones, carbohydrates, aminoacids, growth supplements and antibiotics on somatic embryogenesis and plant differentiation in finger millet  

Microsoft Academic Search

Cultured caryopses of finger millet (Eleusine coracana GAERTN) produced callus from shoot apices or mesocotyls depending upon the concentration of picloram and combination of cytokinins in MS basal medium. On subsequent subcultures, numerous somatic embryos differentiated from the callus on MS medium supplemented with picloram and kinetin. The embryos germinated into complete plants on medium devoid of phytohormones. When different

Susan Eapen; Leela George

1990-01-01

212

Embryogenesis induction in petals of Araujia sericifera  

Microsoft Academic Search

The embryogenic capacity of Araujia sericifera petals and some of the factors involved in the induction of embryos was investigated.\\u000a The influence of 6-benzyladenine and ?-naphthalene acetic acid, light intensity (90 or 5 mol m-2 s-1) and silver thiosulphate (inhibitor of ethylene action) were studied. It was found that petals are an easy system in which\\u000a to induce somatic embryogenesis.

J. M. Torné; P. Rodriguez; A. Manich; I. Claparols; M. A. Santos

1997-01-01

213

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

214

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

215

Visceral and Somatic Hypersensitivity in TNBS induced Colitis in Rats  

PubMed Central

Inflammation of visceral structures in rats has been shown to produce visceral/somatic hyperalgesia. Our objectives were to determine if trinitrobenzene sulfonic acid (TNBS) induced colitis in rats leads to visceral/somatic hypersensitivity. Male Sprague-Dawley rats (200g–250g) were treated with 20 mg of TNBS in 50% ethanol (n=40) or an equivalent volume of ethanol (n=40) or saline (n=25) via the colon. Colonic distension, Von-Frey, Hargreaves, and tail reflex test were used to evaluate for visceral, mechanical, and thermal sensitivity. The rats demonstrated visceral hypersensitivity at 2–28 days following TNBS (p<0.0001). The ethanol treated rats also demonstrated visceral hypersensitivity that resolved after day 14. TNBS treated rats demonstrated somatic hypersensitivity at days 14–28 (p<0.0001) in response to somatic stimuli of the hind-paw. TNBS colitis is associated with visceral and somatic hypersensitivity in areas of somatotopic overlap. This model of colitis should allow further investigation into the mechanisms of visceral and somatic hypersensitivity.

Zhou, QiQi; Price, Donald D.; Caudle, Robert M.; Verne, G. Nicholas

2010-01-01

216

Rapid multiplication of adventitious somatic embryos of Panax ginseng  

Microsoft Academic Search

Somatic embryos and embryogenic callus were initiated from immature zygotic embryos of ginseng (Panax ginseng C.A. Meyer). These somatic embryos were multiplied by adventitious (secondary and tertiary) embryogenesis and their growth and development were dependent on growth hormones in the medium. Auxins, 2,4-d, NAA, and IAA at 1.0 mg l-1 were effective in inducing secondary and tertiary somatic embryos, which

Sarita Arya; Inder Dev Arya; Tage Eriksson

1993-01-01

217

Factors affecting maintenance, proliferation, and germination of secondary somatic embryos of Eucalyptus globulus Labill  

Microsoft Academic Search

The described protocol for repetitive somatic embryogenesis (SE) in Eucalyptus globulus produced more somatic embryos than the primary SE protocol. Primary somatic embryos (induced on MS3NAA) were transferred to the same medium, leading to new cycles of somatic embryos, for at least 2 years. The influence of medium\\u000a (MS and B5), plant growth regulators (auxins and cytokinins), and light on secondary

Gloria Pinto; Yill-Sung Park; Sónia Silva; Lucinda Neves; Clara Araújo; Conceiçăo Santos

2008-01-01

218

Glutathione improves early somatic embryogenesis in Araucaria angustifolia (Bert) O. Kuntze by alteration in nitric oxide emission.  

PubMed

In this work, it was observed a straight relationship between the manipulation of the reduced glutathione (GSH)/glutathione disulfide (GSSG) ratio, nitric oxide emission and quality and number of early somatic embryos in Araucaria angustifolia, a Brazilian endangered native conifer. In low concentrations GSH (0.01 and 0.1mM) is a potential NO scavenger in the culture medium. Furthermore, it can increase the number of early SE formed in cell suspension culture media in a few days. However, the maintenance in this low redox state lead to a loss of early somatic embryos polarization. In gelled culture medium, high levels of GSH (5mM) allows the development of globular embryos presenting a high NO emission on embryo apex, stressing its importance in the differentiation and cell division. Taken together these results indicate that the modification of the embryogenic cultures redox state might be an effective strategy to develop more efficient embryogenic systems in A. angustifolia. PMID:22921001

Vieira, Leila do Nascimento; Santa-Catarina, Claudete; de Freitas Fraga, Hugo Pacheco; Dos Santos, André Luis Wendt; Steinmacher, Douglas André; Schlogl, Paulo Sérgio; Silveira, Vanildo; Steiner, Neusa; Floh, Eny Iochevet Segal; Guerra, Miguel Pedro

2012-06-29

219

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

Microsoft Academic Search

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

Wai-Jane Ho; Indra K. Vasil

1983-01-01

220

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

221

Analysis of the genetic stability of Eucalyptus globulus Labill. somatic embryos by flow cytometry  

Microsoft Academic Search

Flow cytometry was used to measure the nuclear DNA content of Eucalyptus globulus Labill. somatic and zygotic embryos and leaves in order to determine if somatic embryogenesis induces DNA content and ploidy changes in this species. Mature zygotic embryos derived from open-pollination orchard families were collected from a location in the centre of Portugal. One group was kept for nuclear

G. Pinto; J. Loureiro; T. Lopes; C. Santos

2004-01-01

222

Advances in reprogramming somatic cells to induced pluripotent stem cells.  

PubMed

Traditionally, nuclear reprogramming of cells has been performed by transferring somatic cell nuclei into oocytes, by combining somatic and pluripotent cells together through cell fusion and through genetic integration of factors through somatic cell chromatin. All of these techniques changes gene expression which further leads to a change in cell fate. Here we discuss recent advances in generating induced pluripotent stem cells, different reprogramming methods and clinical applications of iPS cells. Viral vectors have been used to transfer transcription factors (Oct4, Sox2, c-myc, Klf4, and nanog) to induce reprogramming of mouse fibroblasts, neural stem cells, neural progenitor cells, keratinocytes, B lymphocytes and meningeal membrane cells towards pluripotency. Human fibroblasts, neural cells, blood and keratinocytes have also been reprogrammed towards pluripotency. In this review we have discussed the use of viral vectors for reprogramming both animal and human stem cells. Currently, many studies are also involved in finding alternatives to using viral vectors carrying transcription factors for reprogramming cells. These include using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. Applications of these techniques have been discussed in detail including its advantages and disadvantages. Finally, current clinical applications of induced pluripotent stem cells and its limitations have also been reviewed. Thus, this review is a summary of current research advances in reprogramming cells into induced pluripotent stem cells. PMID:20336395

Patel, Minal; Yang, Shuying

2010-09-01

223

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

224

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

225

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

226

Development and germination of American chestnut somatic embryos  

Microsoft Academic Search

American chestnut (Castanea dentata (Marsh.) Borkh.) plants were regenerated from developing ovules through somatic embryogenesis.\\u000a On an initiation medium containing 18.18 ?M 2,4-dichlorophenoxyacetic acid and 1.11 ?M 6-benzyladenine (BA), 25 out of 1,576\\u000a ovules were induced to form proembryogenic masses (PEMs). These PEMs were cultivated on a development medium for 4 weeks.\\u000a Individual somatic embryos were then grown on a

Zizhuo Xing; William A. Powell; Charles A. Maynard

1999-01-01

227

Inflorescence proliferation for somatic embryogenesis induction and suspension-derived plant regeneration from banana (Musa AAA, cv. 'Dwarf Cavendish') male flowers.  

PubMed

Availability of explants with adequate embryogenic competence is one of the most important limitations for the development of regenerable cell suspensions in banana. To increase the number and ease of accessibility to potentially embryogenic explants, a novel methodology is described by which young male flower clusters isolated from adult plants are induced to form new flower buds and proliferate in vitro. Different concentrations of the plant growth regulator thidiazuron (TDZ) induced inflorescence proliferation, which could be maintained over time as a continuous source of young flower buds. Intensity of proliferation was evaluated during successive subcultures. At the third cycle of proliferation, the highest multiplication rate (2.89) was obtained on the medium containing 5 microM TDZ. Newly generated floral tissues were assessed for embryogenic competence, resulting in an average embryogenic frequency of 12.5%. The observed embryogenic capacity, together with the recurrent availability of immature flowers, allowed for the direct initiation of cell suspensions from bulked explant cultures. Regular observation and regeneration tests during the development of suspended cell cultures confirmed their embryogenic condition. Produced embryos successfully matured and germinated to regenerate hundreds of somatic in vitro plants. PMID:18259756

Pérez-Hernández, Juan Bernardo; Rosell-García, Purificación

2008-02-08

228

Trueness-To-Type and Yield Components of the Banana Hybrid Cultivar FHIA-18 Plants Regenerated Via Somatic Embryogenesis in a Bioreactor  

Microsoft Academic Search

Summary  A population of 1,500 plants of the banana hybrid ‘FHIA-18’ (AAAB), regenerated from somatic embryos, which were multiplied in bioreactors, showed similar characteristics to plants propagated from shoot tip cultures both in the acclimatization stage and in field experiments carried out in Cuba. The plants originating from somatic embryos were similar to the plants obtained from shoot tips with respect

Rafael Gómez Kosky; Luis Antonio Barranco; Borys Chong Pérez; Dion Daniels; Maritza Reyes Vega; Manuel de Feria Silva

2006-01-01

229

Current methods for inducing pluripotency in somatic cells.  

PubMed

The groundbreaking discovery of reprogramming fibroblasts towards pluripotency merely by introducing four transcription factors (OCT4, SOX2, KLF4 and c-MYC) by means of retroviral transduction has created a promising revolution in the field of regenerative medicine. These so-called induced pluripotent stem cells (iPSCs) can provide a cell source for disease-modelling, drug-screening platforms, and transplantation strategies to treat incurable degenerative diseases, while circumventing the ethical issues and immune rejections associated with the use of non-autologous embryonic stem cells. The risk of insertional mutagenesis, caused both by the viral and transgene nature of the technique has proven to be the major limitation for iPSCs to be used in a clinical setting. In view of this, a variety of alternative techniques have been developed to induce pluripotency in somatic cells. This review provides an overview on current reprogramming protocols, discusses their pros and cons and future challenges to provide safe and transgene-free iPSCs. PMID:23529911

Tavernier, Geertrui; Mlody, Barbara; Demeester, Jo; Adjaye, James; De Smedt, Stefaan C

2013-03-26

230

Stress-induced intrachromosomal recombination in plant somatic cells.  

PubMed Central

Levels of induced homologous recombination between chromosomal repeats in plant somatic cells were examined. Transgenic plants of Nicotiana tabacum hemi- or homozygous for pairs of deletion derivatives of the neomycin phosphotransferase (nptII) marker gene integrated at a single genomic locus were produced. Homologous recombination within the overlapping parts of the nptII gene restored the function and the resulting kanamycin resistance was used for scoring recombination frequency. The recombination events were confirmed by the appearance of a characteristic 1245-base-pair EcoRV fragment detected in all kanamycin-resistant clones tested. The rate of spontaneous recombination was found to be related to the copy number of recombination substrates and was 9 x 10(-5) and 19 x 10(-5) for hemi- and homozygote strains, respectively. Ionizing radiation, mitomycin C, and heat shock markedly increased the frequency of intrachromosomal recombination. Low doses of x-rays (1.25 Gy) enhanced the relative recombination frequency to approximately twice the spontaneous value. The presence of mitomycin C increased the frequency of recombination 9-fold and exposure to an elevated temperature (50 degrees C) increased it 6.5-fold. The x-ray and heat shock treatments reduced cell viability to 53% and 8%, respectively. Mitomycin C treatment had no effect on cell survival. Images

Lebel, E G; Masson, J; Bogucki, A; Paszkowski, J

1993-01-01

231

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.

Rodriguez-Serrano, Maria; Barany, Ivett; Prem, Deepak; Coronado, Maria-Jose; Risueno, Maria C.; Testillano, Pilar S.

2012-01-01

232

Spontaneous chromosome doubling results from nuclear fusion during in vitro maize induced microspore embryogenesis  

Microsoft Academic Search

A multidisciplinary study was carried out to analyse the chromosome doubling process during the early stages of in vitro maize microspore embryogenesis. The main stages (microspore derivatives) that were formed in the course of the culture were analysed. Chromosome number was determined from squashed cells, and DNA content was measured by cytometry. In parallel, an ultrastructural analysis of the microspore

P. Testillano; S. Georgiev; H. L. Mogensen; M. J. Coronado; C. Dumas; M. C. Risueno; E. Matthys-Rochon

2004-01-01

233

Induction of somatic embryogenesis from young, fully expanded leaves of chilli pepper ( Capsicum annuum L.): effect of leaf position, illumination and explant pretreatment with high cytokinin concentrations  

Microsoft Academic Search

The effect of the explant position on the donor plant, illumination and explant pretreatment with high cytokinin concentrations on the induction, proliferation and development of somatic embryos from young, fully expanded leaves of chilli pepper (Capsicum annuum L.) was investigated. Explants were cultured either directly on a solid Murashige and Skoog medium supplemented with 9?M 2,4-dichlorophenoxyacetic acid+12.9?M 6-benzyladenine or incubated

S Kintzios; J. B Drossopoulos; E Shortsianitis; D Peppes

2000-01-01

234

Highly efficient system of plant regeneration from protoplasts of grapevine ( Vitis vinifera L.) through somatic embryogenesis by using embryogenic callus culture and activated charcoal  

Microsoft Academic Search

A simple protocol is described for high frequency plant regeneration from protoplasts isolated from leaf-derived embryogenic calli of grapevine (Vitis vinifera L. cv. Koshusanjaku). The protoplasts successfully divided to form somatic embryos by culturing in gellan gum disc-method in which protoplasts were embedded in 2 g\\/l gellan gum-solidified Nitsch's medium containing 2.0 mg\\/l NAA, 0.5 mg\\/l BA, 0.09 M sucrose

Yan-Ming Zhu; Yoichiro Hoshino; Masaru Nakano; Eikichi Takahashi; Masahiro Mii

1997-01-01

235

Buffer capacity of cotton cells and effects of extracellular pH on growth and somatic embryogenesis in cotton cell suspensions  

Microsoft Academic Search

Summary  This research was designed to: a) characterize the normal pH changes that occur when cotton cell are grown in culture; b)\\u000a determine if cotton cells can regulate the pH of their extracellular medium; and c) explore the effects of starting pH on\\u000a cellular differentiation in culture, including formation of somatic embryos. When an aliquot of cotton cell suspension culture\\u000a (Gossypium

Xiao Min Shang; Ji Ying Huang; Candace H. Haigler; Norma L. Trolinder

1991-01-01

236

DNA methylation dynamics and MET1a-like gene expression changes during stress-induced pollen reprogramming to embryogenesis  

PubMed Central

Stress-induced plant cell reprogramming involves changes in global genome organization, being the epigenetic modifications key factors in the regulation of genome flexibility. DNA methylation, accomplished by DNA methyltransferases, constitutes a prominent epigenetic modification of the chromatin fibre which is locked in a transcriptionally inactive conformation. Changes in DNA methylation accompany the reorganization of the nuclear architecture during plant cell differentiation and proliferation. After a stress treatment, in vitro-cultured microspores are reprogrammed and change their gametophytic developmental pathway towards embryogenesis, the process constituting a useful system of reprogramming in isolated cells for applied and basic research. Gene expression driven by developmental and stress cues often depends on DNA methylation; however, global DNA methylation and genome-wide expression patterns relationship is still poorly understood. In this work, the dynamics of DNA methylation patterns in relation to nuclear architecture and the expression of BnMET1a-like DNA methyltransferase genes have been analysed during pollen development and pollen reprogramming to embryogenesis in Brassica napus L. by a multidisciplinary approach. Results showed an epigenetic reprogramming after microspore embryogenesis induction which involved a decrease of global DNA methylation and its nuclear redistribution with the change of developmental programme and the activation of cell proliferation, while DNA methylation increases with pollen and embryo differentiation in a cell-type-specific manner. Changes in the presence, abundance, and distribution of BnMET1a-like transcripts highly correlated with variations in DNA methylation. Mature zygotic and pollen embryos presented analogous patterns of DNA methylation and MET1a-like expression, providing new evidence of the similarities between both developmental embryogenic programmes.

Testillano, Pilar S.

2012-01-01

237

Differences in the activities of some antioxidant enzymes and in H2O2 content during rhizogenesis and somatic embryogenesis in callus cultures of the ice plant.  

PubMed

Callus was obtained from hypocotyls of Mesembryanthemum crystallinum seedlings cultured on two types of medium-germination medium (GM) and callus induction medium (CIM). Following subculture on shoot induction medium SIM1, the callus formed on CIM medium regenerated roots or somatic embryos, while that obtained on GM medium was non-regenerative. The activities of CuZn-superoxidase dismutase (SOD) were comparable in all calli, but the activities of FeSOD and MnSOD varied according to the activity of photosystem II and the regenerative potential of the tissues. Catalase (CAT) activity was related to H2O2 concentration and affected by both the culture conditions and the morphogenic potential of the calli. The possible role of CAT, SODs and H2O2 in the regeneration of M. crystallinum from callus is discussed. PMID:15517278

Libik, Marta; Konieczny, Robert; Pater, Beata; Slesak, Ireneusz; Miszalski, Zbigniew

2004-10-23

238

Radiation-Induced Bystander Signaling from Somatic Cells to Germ Cells in Caenorhabditis elegans.  

PubMed

Recently, radiation-induced bystander effects (RIBE) have been studied in mouse models in vivo, which clearly demonstrated bystander effects among somatic cells. However, there is currently no evidence for RIBE between somatic cells and germ cells in animal models in vivo. In the current study, the model animal Caenorhabditis elegans was used to investigate the bystander signaling from somatic cells to germ cells, as well as underlying mechanisms. C. elegans body size allows for precise microbeam irradiation and the abundant mutant strains for genetic dissection relative to currently adopted mouse models make it ideal for such analysis. Our results showed that irradiation of posterior pharynx bulbs and tails of C. elegans enhanced the level of germ cell apoptosis in bystander gonads. The irradiation of posterior pharynx bulbs also increased the level of DNA damage in bystander germ cells and genomic instability in the F1 progeny of irradiated worms, suggesting a potential carcinogenic risk in progeny even only somatic cells of parents are exposed to ionizing radiation (IR). It was also shown that DNA damage-induced germ cell death machinery and MAPK signaling pathways were both involved in the induction of germ cell apoptosis by microbeam induced bystander signaling, indicating a complex cooperation among multiple signaling pathways for bystander effects from somatic cells to germ cells. PMID:23931723

Guo, Xiaoying; Sun, Jie; Bian, Po; Chen, Lianyun; Zhan, Furu; Wang, Jun; Xu, An; Wang, Yugang; Hei, Tom K; Wu, Lijun

2013-08-09

239

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

240

A novel eye morphology induced by a P element in somatic tissue of Drosophila melanogaster  

Microsoft Academic Search

We found a specific eye morphology designated as Square, which is induced when some Drosophila melanogaster strains harboring P elements are crossed with the ?2–3 strain carrying a modified P element, P[ry+, ?2–3], which produces transposase in somatic tissue. This phenotype was dominant and also induced in the reciprocal crosses. Square was induced when the ?2–3 strain was crossed with

Eiji Nitasaka; Tsuneyuki Yamazaki

1991-01-01

241

Inflorescence proliferation for somatic embryogenesis induction and suspension-derived plant regeneration from banana ( Musa AAA, cv. ‘Dwarf Cavendish’) male flowers  

Microsoft Academic Search

Availability of explants with adequate embryogenic competence is one of the most important limitations for the development\\u000a of regenerable cell suspensions in banana. To increase the number and ease of accessibility to potentially embryogenic explants,\\u000a a novel methodology is described by which young male flower clusters isolated from adult plants are induced to form new flower\\u000a buds and proliferate in

Juan Bernardo Pérez-Hernández; Purificación Rosell-García

2008-01-01

242

Nonimmunogenic radiation-induced lymphoma: immunity induction by a somatic cell hybrid  

SciTech Connect

The cell line designated PIR-2 is a nonimmunogenic X-ray-induced thymoma of C57BL/6 origin that is unable to induce antitumor immunity in syngeneic lymphocytes in vitro and in mice in vivo. Fusion of PIR-2 with an allogeneic universal fuser A9HT (clone 3c) resulted in the establishment of a somatic cell hybrid designated A9/PIR. C57BL/6 lymphocytes sensitized in vitro with A9/PIR could lyse parental PIR-2 cells, as well as other syngeneic tumors. However, immunization of mice with the hybrid significantly enhanced PIR-2 tumor takes while it partially protected the animals against a challenge with unrelated syngeneic tumors. The results imply that somatic cell hybridization can increase the immunogenicity of an otherwise nonimmunogenic tumor. However, in view of the enhancing effects of hybrid preimmunization on parental tumor cell growth, the possible application of this approach for immunotherapy is questionable.

Yefenof, E.; Goldapfel, M.; Ber, R.

1982-05-01

243

Superior Efficacy of Secreted over Somatic Antigen Display in Recombinant Salmonella Vaccine Induced Protection against Listeriosis  

Microsoft Academic Search

Vaccination provides the most potent measure against infectious disease, and recombinant (r) viable vaccines expressing defined pathogen-derived antigens represent powerful candidates for future vaccination strategies. In a new approach we constructed r-aroA- Salmonella typhimurium displaying p60 or listeriolysin (Hly) antigen of Listeria monocytogenes in secreted or somatic form in the host cell. Vaccination of mice with r-aroA- S. typhimurium induced

Jurgen Hess; Ivo Gentschev; Diana Miko; Manuela Welzel; Christoph Ladel; Werner Goebel; Stefan H. E. Kaufmann

1996-01-01

244

Somatic Embryogenesis in Maritime Pine ( Pinus Pinaster )  

Microsoft Academic Search

\\u000a Maritime pine (Pinus pinaster) has originated from the central and western coasts of the Mediterranean. It is well adapted to sandy soil in temperate climates.\\u000a Small natural forests of maritime pine can still be found in many African and European countries. In France, Pinus pinaster covers 1.4 million hectares and out of which 950000 hectares are located in the southwest

J. Bercetche; M. Pâques

245

Somatic Embryogenesis in Picea Mariana (Mill.)  

Microsoft Academic Search

\\u000a Black spruce (Picea mariana (Miller)) is one of seven spruce species native to North America. Its natural distribution extends from Labrador to Alaska\\u000a and southward to New York, Minnesota, and Montana. The wood of Picea\\u000a mariana is of great economic importance because of its wide use in the manufacture of paper pulp. It forms a considerable part of\\u000a the pulpwood

Krystyna Klimaszewska

246

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.

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

247

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

PubMed

Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) has been suspected of causing de novo copy number variation. To explore this issue, here we perform a whole-genome and transcriptome analysis of 20 human iPSC lines derived from the primary skin fibroblasts of seven individuals using next-generation sequencing. We find that, on average, an iPSC line manifests two copy number variants (CNVs) not apparent in the fibroblasts from which the iPSC was derived. Using PCR and digital droplet PCR, we show that at least 50% of those CNVs are present as low-frequency somatic genomic variants in parental fibroblasts (that is, the fibroblasts from which each corresponding human iPSC line is derived), and are manifested in iPSC lines owing to their clonal origin. Hence, reprogramming does not necessarily lead to de novo CNVs in iPSCs, because most of the 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 F; Rosenberg Belmaker, Lior A; 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

2012-11-18

248

The metabolome of induced pluripotent stem cells reveals metabolic changes occurring in somatic cell reprogramming  

PubMed Central

Metabolism is vital to every aspect of cell function, yet the metabolome of induced pluripotent stem cells (iPSCs) remains largely unexplored. Here we report, using an untargeted metabolomics approach, that human iPSCs share a pluripotent metabolomic signature with embryonic stem cells (ESCs) that is distinct from their parental cells, and that is characterized by changes in metabolites involved in cellular respiration. Examination of cellular bioenergetics corroborated with our metabolomic analysis, and demonstrated that somatic cells convert from an oxidative state to a glycolytic state in pluripotency. Interestingly, the bioenergetics of various somatic cells correlated with their reprogramming efficiencies. We further identified metabolites that differ between iPSCs and ESCs, which revealed novel metabolic pathways that play a critical role in regulating somatic cell reprogramming. Our findings are the first to globally analyze the metabolome of iPSCs, and provide mechanistic insight into a new layer of regulation involved in inducing pluripotency, and in evaluating iPSC and ESC equivalence.

Panopoulos, Athanasia D; Yanes, Oscar; Ruiz, Sergio; Kida, Yasuyuki S; Diep, Dinh; Tautenhahn, Ralf; Herrerias, Aida; Batchelder, Erika M; Plongthongkum, Nongluk; Lutz, Margaret; Berggren, W Travis; Zhang, Kun; Evans, Ronald M; Siuzdak, Gary; Belmonte, Juan Carlos Izpisua

2012-01-01

249

MicroRNA-mediated somatic cell reprogramming.  

PubMed

Since the first report of induced pluripotent stem cells (iPSCs) using somatic cell nuclear transfer (SCNT), much focus has been placed on iPSCs due to their great therapeutic potential for diseases such as abnormal development, degenerative disorders, and even cancers. Subsequently, Takahashi and Yamanaka took a novel approach by using four defined transcription factors to generate iPSCs in mice and human fibroblast cells. Scientists have since been trying to refine or develop better approaches to reprogramming, either by using different combinations of transcription factors or delivery methods. However, recent reports showed that the microRNA expression pattern plays a crucial role in somatic cell reprogramming and ectopic introduction of embryonic stem cell-specific microRNAs revert cells back to an ESC-like state, although, the exact mechanism underlying this effect remains unclear. This review describes recent work that has focused on microRNA-mediated approaches to somatic cell reprogramming as well as some of the pros and cons to these approaches and a possible mechanism of action. Based on the pivotal role of microRNAs in embryogenesis and somatic cell reprogramming, studies in this area must continue in order to gain a better understanding of the role of microRNAs in stem cells regulation and activity. PMID:22961769

Kuo, Chih-Hao; Ying, Shao-Yao

2013-02-01

250

New windows to enhance direct reprogramming of somatic cells towards induced pluripotent stem cells.  

PubMed

Induced pluripotent stem cells are generated by direct reprogramming of somatic cells with the introduction of defined transcription factors or other means. Clinical applications of induced pluripotent stem cells are the latest of stem cell therapy approaches due to overcoming problems associated with insufficient cells from conventional sources and immune rejections. In practice, this is restricted by 4 major barriers including the use of genetic manipulations for delivering the reprogramming factors, low efficiency of this process, slow kinetics of the direct reprogramming, and potential for tumor development. Here, we review the latest achievements in improving reprogramming efficiency by alternative strategies. These alternatives mainly involve the replacement of genetic reprogramming factors with small molecules or other factors. PMID:22166043

Nakhaei-Rad, Saeideh; Bahrami, Ahmad R; Mirahmadi, Mahdi; Matin, Maryam M

2011-12-14

251

Reprogramming events of mammalian somatic cells induced by Xenopus laevis egg extracts.  

PubMed

It is known that differentiated cells can be reprogrammed to an undifferentiated state in oocyte cytoplasm after nuclear transfer. Recently, some reports suggested that Xenopus egg extracts have the ability to reprogram mammalian somatic cells. Reprogramming events of mammalian cells after Xenopus egg extract treatment and after cell culture of extract-treated cells have not been elucidated. In this experiment, we examined reprogramming events in reversibly permeabilized or nonpermeabilized porcine fibroblast cells after Xenopus egg extract treatment. The Xenopus egg-specific histone B4 was assembled on porcine chromatin and nuclear lamin LIII was incorporated into nuclei. Deacetylation of histone H3 at lysine 9 in extract-treated cells was detected in nonpermeabilized cells, suggesting that a part of reprogramming may be induced even in nonpermeabilized cells. Following culture of extract-treated cells, the cells began to express the pluripotent marker genes such as POU5F1 (OCT4) and SOX2 and to form colonies. Reactivation of the OCT4 gene in extract-treated cells was also confirmed in bovine fibroblasts transformed with an OCT4-EGFP construct. These results suggest that nuclei of mammalian cells can be partially reprogrammed to an embryonic state by Xenopus egg extracts and the remodeled cells partly dedifferentiate after cell culture. A system using egg extracts may be useful for understanding the mechanisms and processes of dedifferentiation and reprogramming of mammalian somatic cells after nuclear transfer. PMID:17474094

Miyamoto, Kei; Furusawa, Tadashi; Ohnuki, Mari; Goel, Sandeep; Tokunaga, Tomoyuki; Minami, Naojiro; Yamada, Masayasu; Ohsumi, Keita; Imai, Hiroshi

2007-10-01

252

Potential biochemical markers for somatic embryos of Eurycoma longifolia jack  

Microsoft Academic Search

Biochemical marker is one of the important tools for the early identification and selection of somatic embryogenesis in plants.\\u000a Studies in developing the biochemical marker for somatic embryogenesis ofEurycoma longifolia disclosed that the regenerated and non-regenerated cotyledons as well as embryogenic and non-embryogenic callus were significantly\\u000a different in terms of the total protein content as well as the specific activity

Sobri Hussein; Rusli Ibrahim; Anna Ling Pick Kiong

2006-01-01

253

Enhancement of American chestnut somatic seedling production.  

PubMed

Somatic embryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic seedling production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic seedling production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somatic embryogenesis for mass clonal propagation of the tree. PMID:15789206

Andrade, G M; Merkle, S A

2005-03-24

254

Morphological and molecular characterization of fertile tetraploid somatic hybrids produced by protoplast electrofusion and PEG-induced fusion between Lycopersicon esculentum Mill. and Lycopersicon peruvianum Mill  

Microsoft Academic Search

Mesophyl protoplasts of two genotypes of cultivated tomato (Lycopersicon esculentum Mill.) and one of its wild relative species (Lycopersicon peruvianum Mill.) were fused by using electrofusion and polyethyleneglycol-induced fusion. Forty-three fertile tetraploid somatic hybrid plants, each deriving from separate calli, were recovered from both fusion procedures. Electrofusion appeared more efficient than chemical fusion for the production of somatic hybrids. These

Lean Han San; Fernand Vedel; Darasinh Sihachakr; René Rémy

1990-01-01

255

Identification of cells deficient in signaling-induced alternative splicing by use of somatic cell genetics.  

PubMed Central

In recent years, a growing number of mammalian genes have been shown to undergo alternative splicing in response to extracellular stimuli. However, the factors and pathways involved in such signal-induced alternative splicing are almost entirely unknown. Here we describe a novel method for identifying candidate trans-acting factors that are involved in regulating mammalian alternative splicing, using the activation-induced alternative splicing of the human CD45 gene in T cells as a model system. We generated a cell line that stably expresses a CD45 minigene-based GFP reporter construct, such that the levels of green-fluorescent protein (GFP) expressed in the cell reflect the splicing state of the endogenous CD45 gene. Following mutagenesis of this cell line, and multiple rounds of selection for cells that displayed aberrant levels of GFP expression, we isolated several cell lines that are at least partially defective in their ability to support regulated alternative splicing of endogenous CD45 pre-mRNA in response to cell stimulation. Thus we have successfully isolated mutants in a mammalian alternative splicing pathway through use of a somatic cell-based genetic screen. This study clearly demonstrates the feasibility of using genetic screens to further our understanding of the regulation of mammalian splicing, particularly as it occurs in response to environmental cues.

Sheives, Paul; Lynch, Kristen W

2002-01-01

256

Somatic hybridization by electrofusion of banana protoplasts  

Microsoft Academic Search

Somatic hybridization between triploid and diploid bananas was attempted by using protoplast electrofusion and nurse culture\\u000a techniques. Protoplasts from embryogenic cell suspensions of 'Maçă' (Musa sp. AAB group) were fused with protoplasts from nonembryogenic calli of`Lidi' (Musa sp. AA group). Direct somatic embryogenesis was observed when the fusion-treated protoplasts were cultured with rice nurse\\u000a cells (Oryza sativa L. A-58 line).

Kazumitsu Matsumoto; Alberto Duarte Vilarinhos; Seibi Oka

2002-01-01

257

Enolases: storage compounds in seeds? Evidence from a proteomic comparison of zygotic and somatic embryos of Cyclamen persicum Mill  

Microsoft Academic Search

Somatic embryogenesis is well established for the economic relevant ornamental crop Cyclamen and thus could supplement the elaborate propagation via seeds. However, the use of somatic embryogenesis for commercial large\\u000a scale propagation is still limited due to physiological disorders and asynchronous development within emerged embryos. To\\u000a overcome these problems, profound knowledge of the physiological processes in Cyclamen embryogenesis is essential.

Christina Rode; Sébastien Gallien; Dimitri Heintz; Alain Van Dorsselaer; Hans-Peter Braun; Traud Winkelmann

2011-01-01

258

Induced somatic sector analysis of cellulose synthase (CesA) promoter regions in woody stem tissues.  

PubMed

The increasing focus on plantation forestry as a renewable source of cellulosic biomass has emphasized the need for tools to study the unique biology of woody genera such as Eucalyptus, Populus and Pinus. The domestication of these woody crops is hampered by long generation times, and breeders are now looking to molecular approaches such as marker-assisted breeding and genetic modification to accelerate tree improvement. Much of what is known about genes involved in the growth and development of plants has come from studies of herbaceous models such as Arabidopsis and rice. However, transferring this information to woody plants often proves difficult, especially for genes expressed in woody stems. Here we report the use of induced somatic sector analysis (ISSA) for characterization of promoter expression patterns directly in the stems of Populus and Eucalyptus trees. As a case study, we used previously characterized primary and secondary cell wall-related cellulose synthase (CesA) promoters cloned from Eucalyptus grandis. We show that ISSA can be used to elucidate the phloem and xylem expression patterns of the CesA genes in Eucalyptus and Populus stems and also show that the staining patterns differ in Eucalyptus and Populus stems. These findings show that ISSA is an efficient approach to investigate promoter function in the developmental context of woody plant tissues and raise questions about the suitability of heterologous promoters for genetic manipulation in plant species. PMID:23132521

Creux, Nicky M; Bossinger, Gerd; Myburg, Alexander A; Spokevicius, Antanas V

2012-11-07

259

Hostility and its association with behaviorally induced and somatic coronary risk indicators in finnish adolescents and young adults  

Microsoft Academic Search

The association of hostility to behaviorally induced (i.e. smoking behavior, alcohol consumption and physical activity) and somatic coronary risk indicators (i.e. LDL- and HDL-cholesterol, systolic and diastolic blood pressure and obesity) was studied in a randomly selected representative sample of healthy adolescents and young adults (n = 1609). The question was whether the association, previously found between hostility and CHD

Katri Räikkönen; Liisa Keltikangas-Järvinen

1991-01-01

260

Systems Biology of Embryogenesis  

PubMed Central

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

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

2010-01-01

261

Plant regeneration from pea protoplasts via somatic embyogenesis  

Microsoft Academic Search

Plant regeneration via somatic embryogenesis was obtained from pea protoplasts. Strong auxins (picloram or 2.4-D) and increased osmolarity of the medium were necessary for embryo induction. Relatively high amounts of embryogenic calli could be obtained in 2 genotypes. After a period on hormone-free medium, a second induction of somatic embryos was possible. Further development of somatic embryos was accomplished on

Renate Lehminger-Mertens; Hans-Jörg Jacobsen

1989-01-01

262

Embryogenic calli induced in interspecific (Elaeis guineensis x E. oleifera) hybrid zygotic embryos  

Microsoft Academic Search

The hybridization between oil palm (Elaeis guineensis) and caiaué (E. oleifera) plants is directed to obtain progenies presenting high yields like oil palm but with reduced shoot height and resistance to lethal yellowing like caiaué. Cloning F1, BC1 and BC2 progenies can make the replication of selection trials easier. The objective of this work was to induce somatic embryogenesis in

Paula Cristina da Silva; Ricardo Lopes; Larissa Alexandra; Cardoso Moraes; Nonato Vieira da Cunha

263

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

PubMed

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; Vizzard, Margaret A

2013-05-08

264

Visceral and somatic hypersensitivity in a subset of rats following TNBS-induced colitis  

PubMed Central

Background Chronic abdominal pain is one of the most common gastrointestinal symptoms experienced by patients. Visceral hypersensitivity has been shown to be a biological marker in many patients with chronic visceral pain. We have previously shown that IBS patients with visceral hypersensitivity also have evidence of thermal hyperalgesia of the hand/foot. Objective The objective of the current study was to develop an animal model of chronic visceral and somatic hypersensitivity in rats treated with intracolonic trinitrobenzene sulfonic acid. Design Male Sprague–Dawley rats (200–250 g) were treated with either 20 mg/rat trinitrobenzene sulfonic acid (TNBS, Sigma Chemical Co.) in 50% ethanol (n = 75), an equivalent volume of 50% ethanol (n = 20) or an equivalent volume of saline (n = 20). The agents were delivered with a 24-gauge catheter inserted into the lumen of the colon. Mechanical and thermal behavioral tests were performed using an automated von Frey and Hargreaves device to evaluate somatic hyperalgesia. Colonic distension was performed using an automated distension device to evaluate visceral pain thresholds. All animals were tested 16 weeks after TNBS treatment following complete resolution of the colitis. Results At 16 weeks, 24% of the treated rats (18/75 rats) still exhibited evidence of visceral as well as somatic hypersensitivity compared to saline- and ethanol-treated rats. Conclusion Transient colonic inflammation leads to chronic visceral and somatic hypersensitivity in a subset of rats. These findings are similar to the subset of patients who develop chronic gastrointestinal symptoms following enteric infection.

Zhou, QiQi; Price, Donald D.; Caudle, Robert M.; Verne, G. Nicholas

2010-01-01

265

Post-stimulation Inhibitory Effect on Reflex Bladder Activity Induced by Activation of Somatic Afferent Nerves in the Foot  

PubMed Central

Purpose To determine if transcutaneous electrical stimulation of somatic afferent nerves in the foot of cats can induce a post-stimulation increase in bladder capacity. Materials and Methods In ?-chloralose anesthetized cats (N=12) electrical stimulation (5 Hz) was applied to the skin of the hind foot for two periods of 30 minutes via dual pad electrodes attached on the plantar and dorsal surfaces (combination 1-2) or at two sites on the plantar surface (combination 1-3). The post-stimulation effect was examined by performing repeated CMGs following 30 minute stimulation. In the control group (N=12) the isovolumetric contractions were allowed to continue during each 30 minute period without stimulation. Results Stimulation inhibited isovolumetric rhythmic bladder contractions. The bladder capacity was not increased after the first 30 minute foot stimulation via electrode combination 1-2, but was significantly increased 47.5±2.9% after the second 30 minute stimulation via electrode combination 1-3. After inducing the post-stimulation effect, the foot stimulation applied during CMGs via electrode combinations 1-2 or 1-3 elicited a further increase in bladder capacity (23.26±17.64% and 20.07±18.59% respectively). Conclusions This study shows that the transcutaneous plantar electrical stimulation of somatic afferent nerves in the foot can induce a post-stimulation increase in bladder capacity, suggesting that an intermittent stimulation pattern rather than a continuous stimulation might be effective in clinical applications to treat overactive bladder symptoms.

Chen, Guoqing; Larson, Jeffrey A.; Ogagan, P. Dafe; Shen, Bing; Wang, Jicheng; Roppolo, James R.; de Groat, William C.; Tai, Changfeng

2011-01-01

266

On the mechanisms of induced somatic recombination by certain fungicides in Aspergillus nidulans.  

PubMed

Four fungicides interfered with the segregation of chromosomes at mitosis of Aspergillus nidulans by increasing the somatic recombination, shown as colour sectors in green colonies, in a strain heterozygous for spore colour mutations. In an attempt to discover the mechanisms by which these fungicides increased the somatic recombination, a prototrophic diploid strain, heterozygous for colour and several other appropriate markers in all chromosomes, was used which enabled the detection and classification of all colour recombinants to be made by genetic analysis. The fungicides investigated were: benomyl (methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate) a benzimidazole derivative, botran (2,6-dichloro-4-nitroaniline) and chloroneb (1,4-dichloro-2,5-dimethoxybenzene) of the aromatic hydrocarbon group of fungicides, and the antibiotic actinomycin D. At least three different mechanisms, non-disjunction, mitotic crossing-over and breakage-deletion, were found to be responsible for the recombinogenic activity of the compounds studied. PMID:357961

Kappas, A

1978-08-01

267

Increase induced by colchicine in the incidence of somatic crossing over in Glycine max  

Microsoft Academic Search

The frequency of somatic crossing over in Glycine max has been significantly increased by soaking the dry seeds in aqueous solutions of 0.0025, 0.005 and 0.01% colchicine. This increase was quite consistent for several treatments involving time × concentration interaction as well as in cases where post-treatment with mitomycin C was given. Results indicate that colchicine is inefficient in disturbing

B. K. Vig

1970-01-01

268

Inactivation of the Retinoblastoma Tumor Suppressor Induces Apoptosis Protease activating Factor1 Dependent and Independent Apoptotic Pathways during Embryogenesis1  

Microsoft Academic Search

Inactivation of the retinoblastoma (Rb) tumor suppressor in the mouse induces mid-gestational death accompanied by massive apoptosis in cer- tain tissues. Herein, we analyzed the role of the apoptosis protease- activating factor Apaf-1, an essential component of the apoptosome, in mediating apoptosis in Rb-deficient mice. Analysis of compound mutant embryos lacking Rb and Apaf-1 revealed that Apaf-1 was absolutely required

Zhong Guo; Shi Yikang; Hiroki Yoshida; Tak W. Mak; Eldad Zacksenhaus

2001-01-01

269

The roles of the reprogramming factors Oct4, Sox2 and Klf4 in resetting the somatic cell epigenome during induced pluripotent stem cell generation  

PubMed Central

Somatic cell reprogramming to induced pluripotent stem (iPS) cells by defined factors is a form of engineered reverse development carried out in vitro. Recent investigation has begun to elucidate the molecular mechanisms whereby these factors function to reset the epigenome.

2012-01-01

270

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.

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

2011-01-01

271

Will brain cells derived from induced pluripotent stem cells or directly converted from somatic cells (iNs) be useful for schizophrenia research?  

PubMed

The reprogramming of nonneuronal somatic cells to induced pluripotent stem cells and their derivation to functional brain cells as well as the related methods for direct conversion of somatic cells to neurons have opened up the possibility of conducting research on cellular disease models from living schizophrenia patients. We review the published literature on schizophrenia that has used this rapidly developing technology, highlighting the need for specific aims and reproducibility. The key issues for consideration for future schizophrenia research in this field are discussed and potential investigations using this technology are put forward for critical assessment by the reader. PMID:23884351

Filippich, Cheryl; Wolvetang, Ernst J; Mowry, Bryan J

2013-07-24

272

Influenza-B-virus-induced eye and brain malformations during early chick embryogenesis and localization of the viral RNA in specific areas  

Microsoft Academic Search

Influenza is prevalent worldwide, and the teratogenic effects of influenza infection have been suspected to occur within the developing central nervous system. We herein report the sequelae of influenza B viral infection during early chick embryogenesis. Chick embryos at Hamburger-Hamilton stage 9 were infected by an in ovo injection under the blastoderm of influenza B virus (B\\/Taiwan\\/25\\/99). At 48 h

Bo-Yie Chen; Han-Hsin Chang; Hui-Ling Chiou; David Pei-Cheng Lin

2004-01-01

273

Influenza-B-Virus-Induced Eye and Brain Malformations during Early Chick Embryogenesis and Localization of the Viral RNA in Specific Areas  

Microsoft Academic Search

Influenza is prevalent worldwide, and the teratogenic effects of influenza infection have been suspected to occur within the developing central nervous system. We herein report the sequelae of influenza B viral infection during early chick embryogenesis. Chick embryos at Hamburger-Hamilton stage 9 were infected by an in ovo injection under the blastoderm of influenza B virus (B\\/Taiwan\\/25\\/99). At 48 h

Bo-Yie Chen; Han-Hsin Chang; Hui-Ling Chiou; David Pei-Cheng Lin

2004-01-01

274

Somatic Embryogenesis in Indian Olive ( Elaeocarpus robustus L)  

Microsoft Academic Search

Elaeocarpus robustus L. (Indian olive, Fam. Elaeocarpaceae) is a well-known evergreen fruit tree and 25 m tall. It is native to Bangladesh and India. The tree is of great economic importance for its fruits and timber. The importance of fleshy sour fruits having citric acid occupy an important position in tropical countries since they provide needed vitamin-C in diets. Its

Shyamal K. Roy; Pinaki Sinha

275

Somatic embryogenesis and plant regeneration in Quercus acutissima  

Microsoft Academic Search

Immature embryos of Quercus acutissima were collected weekly beginning 5 weeks post-fertilization and cultured on modified MS(Murashige and Skoog) medium containing 1,000 mg\\/l glutamine and 5 mM proline with different combinations of IBA(0.5–10.0 mg\\/l) and BA(0 or 1.0 mg\\/l) in light. The highest percentage of embryogenic cultures occurred on the medium containing 0.5 mg\\/l IBA or 1.0 mg\\/l BA and

Yong Wook Kim; Bong Choon Lee; Suk Koo Lee; Suk Sung Jang

1994-01-01

276

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

277

Somatic embryogenesis in Jatropha curcas Linn., an important biofuel plant  

Microsoft Academic Search

Jatropha curcas L. is one potential source of non-edible biofuel-producing energy crop. Its importance also lies in its medicinal properties.\\u000a The species is primarily propagated through heterozygous seeds, and thus the seed oil content varies from 4 to 40%. Moreover,\\u000a due to its perennial nature, seed setting requires 2 to 3 years time. The seed viability and rate of germination are

Timir baran Jha; Priyanka Mukherjee; Mukul Manjari Datta

2007-01-01

278

Somatic embryogenesis in wild relatives of cotton (Gossypium Spp.).  

PubMed

Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods. PMID:16532531

Rao, Abdul Qayyum; Hussain, S Sarfraz; Shahzad, M Saqib; Bokhari, S Yassir Abbas; Raza, M Hashim; Rakha, Allah; Majeed, A; Shahid, A Ali; Saleem, Zafar; Husnain, Tayyab; Riazuddin, S

2006-04-01

279

Somatic embryogenesis and plant regeneration of Nerium oleander  

Microsoft Academic Search

Leaf explants of Nerium oleander L. produced masses of callus when both an auxin and a cytokinin were included in the medium. Leaves cultured on the B5 medium of Gamborg et al. supplemented with 2,4-dichlorophenoxyacetic acid (2,4-d; 9.05 µM) plus benzyladenine (BA; 4.4 µM) produced callus and profuse rhizogenesis was observed from callus developed from older leaves. On Murashige &

Isabel Santos; Isabel Guimarăes; Roberto Salema

1994-01-01

280

Somatic embryogenesis and polyamines in woody plants - Treesearch  

Treesearch

... the biochemical basis of hormonal regulation of the developmental process. This knowledge should lead to the planning of media and various treatments that allow ... This article was written and prepared by U.S. Government employees on  ...

281

Somatic embryogenesis in wild relatives of cotton (Gossypium Spp.)  

PubMed Central

Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.

Rao, Abdul Qayyum; Hussain, S. Sarfraz; Shahzad, M. Saqib; Bokhari, S. Yassir Abbas; Raza, M. Hashim; Rakha, Allah; Majeed, A.; Shahid, A. Ali; Saleem, Zafar; Husnain, Tayyab; Riazuddin, S.

2006-01-01

282

DEVELOPING SOMATIC EMBRYOGENIC CULTURE SYSTEM AND PLANT REGENERATION IN BANANA  

Microsoft Academic Search

A b s t r a c t Bananas and plantains are one of the major fruit crops and a staple food in the developing world. Most of the edible bananas are triploid, highly sterile and hence integration of in vitro techniques banana improvement becomes crucial. In this milieu, technique of somatic embryogenesis in combination with genetic manipulation, has become

Meenakshi Sidha; P. Suprasanna; V. A. Bapat; U. G. Kulkarni; B. N. Shinde

2007-01-01

283

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

284

Somatic cell nuclear transfer in the sheep induces placental defects that likely precede fetal demise.  

PubMed

The efficiency of cloning by somatic cell nuclear transfer (SCNT) is poor in livestock with approximately 5% of transferred cloned embryos developing to term. SCNT is associated with gross placental structural abnormalities. We aimed to identify defects in placental histology and gene expression in failing ovine cloned pregnancies to better understand why so many clones generated by SCNT die in utero. Placentomes from SCNT pregnancies (n = 9) and age matched, naturally mated controls (n = 20) were collected at two gestational age ranges (105-134 days and 135-154 days; term = 147 days). There was no effect of cloning on total placental weight. However, cloning reduced the number of placentomes at both gestational ages (105-134 days: control 55.0 +/- 4.2, clone 44.7 +/- 8.0 and 135-154 days: control 72.2 +/- 5.1, clone 36.6 +/- 5.1; P < 0.001) and increased the mean individual placentome weight (105-134 days: control 10.6 +/- 1.3 g, clone 18.6 +/- 2.8 g and 135-154 days: control 6.6 +/- 0.6 g, clone 7.0 +/- 2.0 g; P < 0.02). Placentomes from cloned pregnancies had a significant volume of shed trophoblast and fetal villous hemorrhage, absent in controls, at both gestational age ranges (P < 0.001) that was shown to be apoptotic by activated caspase-3 immunoreactivity. Consequently, the volume of intact trophoblast was reduced and the arithmetic mean barrier thickness of trophoblast through which exchange occurs was altered (P < 0.001) at both gestational age ranges in clones. In addition, cloning reduced placental expression of key genes in placental differentiation and function. Thus, cloning by SCNT results in both gross and microscopic placental abnormalities. We speculate that trophoblast apoptosis, shedding, and hemorrhage may be causal in fetal death in ovine clones. PMID:17244750

Fletcher, C J; Roberts, C T; Hartwich, K M; Walker, S K; McMillen, I C

2007-01-01

285

Microspore Embryogenesis in Selected Medicinal and Ornamental Species of the Asteraceae  

Microsoft Academic Search

Isolated microspore culture experiments were carried out to induce microspore embryogenesis in Chamomilla recutita, Solidago virgaurea, Sanvitalia procumbens of the Asteracea, and Valeriana officinalis of the Valerianaceae. The Asteracea is one the largest plant families of commercial significance for medicinal, aromatic, food and ornamental\\u000a use. Availability of protocols for an efficient production of doubled haploids via microspore embryogenesis would facilitate

U. Bal; A. Touraev

286

Reprogramming of somatic cells after fusion with induced pluripotent stem cells and nuclear transfer embryonic stem cells.  

PubMed

In this study we examine whether a somatic cell, once returned to a pluripotent state, gains the ability to reprogram other somatic cells. We reprogrammed mouse embryonic fibroblasts by viral induction of oct4, sox2, c-myc, and klf-4 genes. Upon fusion of the resulting iPS cells with somatic cells harboring an Oct4-GFP transgene we observed, GFP expression along with activation of Oct4 from the somatic genome, expression of key pluripotency genes, and positive immunostaining for Oct4, SSEA-1, and alkaline phosphatase. The iPS-somatic hybrids had the ability to differentiate into cell types indicative of the three germ layers and were able to localize to the inner cell mass of aggregated embryos. Furthermore, ntES cells were used as fusion partners to generate hybrids, which were also confirmed to be reprogrammed to a pluripotent state. These results demonstrate that once a somatic cell nucleus is reprogrammed, it acquires the capacity and potency to reprogram other somatic cells by cell fusion and shares this functional property with normal embryonic stem (ES) cells. PMID:19637940

Sumer, Huseyin; Jones, Karen L; Liu, Jun; Heffernan, Corey; Tat, Pollyanna A; Upton, Kyle R; Verma, Paul J

2010-02-01

287

Serum Starvation Induced Cell Cycle Synchronization Facilitates Human Somatic Cells Reprogramming  

Microsoft Academic Search

Human induced pluripotent stem cells (iPSCs) provide a valuable model for regenerative medicine and human disease research. To date, however, the reprogramming efficiency of human adult cells is still low. Recent studies have revealed that cell cycle is a key parameter driving epigenetic reprogramming to pluripotency. As is well known, retroviruses such as the Moloney murine leukemia virus (MoMLV) require

Mengfei Chen; Jingjing Huang; Xuejiao Yang; Bingqian Liu; Weizhong Zhang; Li Huang; Fei Deng; Jian Ma; Yujing Bai; Rong Lu; Bing Huang; Qianying Gao; Yehong Zhuo; Jian Ge

2012-01-01

288

The metabolome of induced pluripotent stem cells reveals metabolic changes occurring in somatic cell reprogramming  

Microsoft Academic Search

Metabolism is vital to every aspect of cell function, yet the metabolome of induced pluripotent stem cells (iPSCs) remains largely unexplored. Here we report, using an untargeted metabolomics approach, that human iPSCs share a pluripotent metabolomic signature with embryonic stem cells (ESCs) that is distinct from their parental cells, and that is characterized by changes in metabolites involved in cellular

Athanasia D Panopoulos; Oscar Yanes; Sergio Ruiz; Yasuyuki S Kida; Dinh Diep; Ralf Tautenhahn; Aída Herrerías; Erika M Batchelder; Nongluk Plongthongkum; Margaret Lutz; W Travis Berggren; Kun Zhang; Ronald M Evans; Gary Siuzdak; Juan Carlos Izpisua Belmonte

2012-01-01

289

Reprogramming mammalian somatic cells.  

PubMed

Somatic cell nuclear transfer (SCNT), the technique commonly known as cloning, permits transformation of a somatic cell into an undifferentiated zygote with the potential to develop into a newborn animal (i.e., a clone). In somatic cells, chromatin is programmed to repress most genes and express some, depending on the tissue. It is evident that the enucleated oocyte provides the environment in which embryonic genes in a somatic cell can be expressed. This process is controlled by a series of epigenetic modifications, generally referred to as "nuclear reprogramming," which are thought to involve the removal of reversible epigenetic changes acquired during cell differentiation. A similar process is thought to occur by overexpression of key transcription factors to generate induced pluripotent stem cells (iPSCs), bypassing the need for SCNT. Despite its obvious scientific and medical importance, and the great number of studies addressing the subject, the molecular basis of reprogramming in both reprogramming strategies is largely unknown. The present review focuses on the cellular and molecular events that occur during nuclear reprogramming in the context of SCNT and the various approaches currently being used to improve nuclear reprogramming. A better understanding of the reprogramming mechanism will have a direct impact on the efficiency of current SCNT procedures, as well as iPSC derivation. PMID:22979962

Rodriguez-Osorio, N; Urrego, R; Cibelli, J B; Eilertsen, K; Memili, E

2012-09-12

290

Fishery-Induced Selection for Slow Somatic Growth in European Eel  

PubMed Central

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.

Bevacqua, Daniele; Capoccioni, Fabrizio; Melia, Paco; Vincenzi, Simone; Pujolar, Jose M.; De Leo, Giulio A.; Ciccotti, Eleonora

2012-01-01

291

Embryological Perspective of Sexual Somatic Development in Ciliated Protozoa: Implications on Immortality, Sexual Reproduction and Inheritance of Acquired Characters  

Microsoft Academic Search

This essay addresses somatic development during sexual reproduction of ciliated protozoa, which is interpreted as an embryological phenomenon resembling embryogenesis of multicellular organisms. The uniqueness of this somatic development, as distinct from asexual development, resides in its dependence on new information associated with the germ nucleus, and on its involvement of both maternal and postzygotic informational inputs. This understanding derives

F. Ng Stephen

1990-01-01

292

The effects of microgravity on gametogenesis, fertilization, and early embryogenesis  

Microsoft Academic Search

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

X. Tan

2006-01-01

293

Somatic and autonomic small fiber neuropathy induced by bortezomib therapy: an immunofluorescence study.  

PubMed

Bortezomib is a new chemotherapeutic agent approved for the treatment of relapsed/refractory and newly diagnosed multiple myeloma. One of the major side effects of bortezomib is a peripheral length-dependent sensory axonal neuropathy and, less frequently, a small fiber neuropathy. Autonomic symptoms like postural dizziness, syncope, diarrhoea, ileus, impotence and urinary disturbances have been reported, nevertheless, autonomic neuropathy has never been characterized. We describe by means of immunofluorescence, the involvement of autonomic skin nerve fibers in three patients with small fiber neuropathy induced by bortezomib treatment. PMID:21290160

Giannoccaro, Maria Pia; Donadio, Vincenzo; Gomis Pčrez, Carolina; Borsini, Walter; Di Stasi, Vitantonio; Liguori, Rocco

2011-02-03

294

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

295

AID AND SOMATIC HYPERMUTATION  

PubMed Central

In response to an assault by foreign organisms, peripheral B cells can change their antibody affinity and isotype by somatically mutating their genomic DNA. The ability of a cell to modify its DNA is exceptional in light of the potential consequences of genetic alterations to cause human disease and cancer. Thus, as expected, this mechanism of antibody diversity is tightly regulated and coordinated through one protein, activation induced deaminase (AID). AID produces diversity by converting cytosine to uracil within the immunoglobulin loci. The deoxyuracil residue is mutagenic when paired with deoxyguanosine, since it mimics thymidine during DNA replication. Additionally, B cells can manipulate the DNA repair pathways so that deoxyuracils are not faithfully repaired. Therefore, an intricate balance exists which is regulated at multiple stages to promote mutation of immunoglobulin genes, while retaining integrity of the rest of the genome. Here we discuss and summarize the current understanding of how AID functions to cause somatic hypermutation.

Maul, Robert W.; Gearhart, Patricia J.

2010-01-01

296

Anisotropic growth shapes intestinal tissues during embryogenesis  

PubMed Central

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen. For avians (chicks’ and turkeys’ embryos), it has been shown that, a few days after fertilization, the mucosal epithelium of the duodenum is smooth, and then folds emerge, which present 2 d later a pronounced zigzag instability. Many debates and biological studies are devoted to this specific morphology, which regulates the cell renewal in the intestine. After reviewing experimental results about duodenum morphogenesis, we show that a model based on simplified hypothesis for the growth of the mesenchyme can explain buckling and postbuckling instabilities. Being completely analytical, it is based on biaxial compressive stresses due to differential growth between layers and it predicts quantitatively the morphological changes. The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability. The model is compared with available experimental data on chick’s duodenum and can be applied to other intestinal tissues, the zigzag being a common and spectacular microstructural pattern of intestine embryogenesis.

Ben Amar, Martine; Jia, Fei

2013-01-01

297

Influenza-B-virus-induced eye and brain malformations during early chick embryogenesis and localization of the viral RNA in specific areas.  

PubMed

Influenza is prevalent worldwide, and the teratogenic effects of influenza infection have been suspected to occur within the developing central nervous system. We herein report the sequelae of influenza B viral infection during early chick embryogenesis. Chick embryos at Hamburger-Hamilton stage 9 were infected by an in ovo injection under the blastoderm of influenza B virus (B/Taiwan/25/99). At 48 h after infection, gross malformations of the eye and brain, ranging from 25 to 58% of 168 infected embryos, were observed, in contrast to 3-6% among 71 mock-infected controls (p < 0.0001 for both eye and brain malformations). Histological analyses showed extensive tissue degeneration and aggregates of cells in the head mesenchyme, suggesting cell death and heterotopia. Influenza B viral RNA was directly localized by in situ hybridization with probes specific for the HA segment. Viral RNA was extensively detected in the head surface ectoderm and in the lung bud. In the developing brain, viral RNA was specifically located in the anterior neural retina, habenular area, mid-thalamus, and rhombencephalon. Our data show that influenza B virus can be a teratogenic agent in neural and nonneural embryonic tissues, raising concern for transplacental infection during early pregnancy. PMID:14966377

Chen, Bo-Yie; Chang, Han-Hsin; Chiou, Hui-Ling; Lin, David Pei-Cheng

298

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.

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

2011-01-01

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

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

Rathbone, Alex J; Liddell, Susan; Campbell, Keith H S

2013-06-15

300

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

301

Analysis of human and mouse reprogramming of somatic cells to induced pluripotent stem cells. What is in the plate?  

PubMed

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 into pluripotent cells, though the cellular and genetic consequences of reprogramming remain largely unknown. Furthermore, it is still unclear whether induced pluripotent stem cells (iPSCs) are truly functionally equivalent to embryonic stem cells (ESCs) and if they demonstrate the same differentiation potential as ESCs. There are a large number of reprogramming experiments published so far encompassing genome-wide transcriptional profiling of the cells of origin, the iPSCs and ESCs, which are used as standards of pluripotent cells and allow us to provide here an in-depth analysis of transcriptional profiles of human and mouse cells before and after reprogramming. When compared to ESCs, iPSCs, as expected, share a common pluripotency/self-renewal network. Perhaps more importantly, they also show differences in the expression of some genes. We concentrated our efforts on the study of bivalent domain-containing genes (in ESCs) which are not expressed in ESCs, as they are supposedly important for differentiation and should possess a poised status in pluripotent cells, i.e. be ready to but not yet be expressed. We studied each iPSC line separately to estimate the quality of the reprogramming and saw a correlation of the lowest number of such genes expressed in each respective iPSC line with the stringency of the pluripotency test achieved by the line. We propose that the study of expression of bivalent domain-containing genes, which are normally silenced in ESCs, gives a valuable indication of the quality of the iPSC line, and could be used to select the best iPSC lines out of a large number of lines generated in each reprogramming experiment. PMID:20862250

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

2010-09-17

302

Temperature-Induced Extended Helix/Random Coil Transitions in a Group 1 Late Embryogenesis-Abundant Protein from Soybean1  

PubMed Central

Group 1 late embryogenesis-abundant (LEA) proteins are a subset of hydrophilins that are postulated to play important roles in protecting plant macromolecules from damage during freezing, desiccation, or osmotic stress. To better understand the putative functional roles of group 1 LEA proteins, we analyzed the structure of a group 1 LEA protein from soybean (Glycine max). Differential scanning calorimetry of the purified, recombinant protein demonstrated that the protein assumed a largely unstructured state in solution. In the presence of trifluoroethanol (50% [w/v]), the protein acquired a 30% ?-helical content, indicating that the polypeptide is highly restricted to adopt ?-helical structures. In the presence of sodium dodecyl sulfate (1% [w/v]), 8% of the polypeptide chain adopted an ?-helical structure. However, incubation with phospholipids showed no effect on the protein structure. Ultraviolet absorption and circular dichroism spectroscopy revealed that the protein existed in equilibrium between two conformational states. Ultraviolet absorption spectroscopy studies also showed that the protein became more hydrated upon heating. Furthermore, circular dichroism spectral measurements indicated that a minimum of 14% of amino acid residues existed in a solvent-exposed, left-handed extended helical or poly (l-proline)-type (PII) conformation at 20°C with the remainder of the protein being unstructured. The content of PII-like structure increased as temperature was lowered. We hypothesize that by favoring the adoption of PII structure, instead of the formation of ?-helical or ?-sheet structures, group 1 LEA proteins retain a high content of surface area available for interaction with the solvent. This feature could constitute the basis of a potential role of LEA proteins in preventing freezing, desiccation, or osmotic stress damage.

Soulages, Jose L.; Kim, Kangmin; Walters, Christina; Cushman, John C.

2002-01-01

303

Contrasting globulin and cysteine proteinase gene expression patterns reveal fundamental developmental differences between zygotic and somatic embryos of oil palm.  

PubMed

Oil palm (Elaeis guineensis Jacq.) somatic embryos differ from zygotic embryos in that they accumulate only small amounts of storage proteins. We compared the balance between deposition and degradation of storage proteins during zygotic or somatic embryogenesis and germinative growth in the two types of embryos. During mid to late zygotic embryogenesis, storage proteins accumulated and globulin 7S (GLO7A) gene transcripts were detected, whereas neither protease activity nor cysteine proteinase (CPR) gene transcripts were detected. Globulin degradation occurred after 8 days of in vitro germination in zygotic embryos and was accompanied by a decrease in GLO7A transcripts. Transcripts of three cysteine proteinase genes of the papain family were detected as early as Day 2 of in vitro germination. Several proteolytically active protein bands were identified by zymography, and CPR-like proteins were detected with an antibody raised against the Vicia sativa L. cysteine proteinase CPR1. Protease activities and CPR-like proteins were observed from Day 8 onward when globulin degradation occurred. During somatic embryogenesis and subsequent germinative growth, only small amounts of storage proteins accumulated, even though GLO7A transcripts were detected. Two of the three cysteine proteinase genes were expressed throughout both somatic embryogenesis and germinative growth. Protease activities and CPR-like protein species were detected in somatic embryos at several developmental stages. In contrast to zygotic embryogenesis, the accumulation of globulins and their subsequent mobilization appear to be concomitant processes during somatic embryogenesis, which could explain the low accumulation of storage proteins in somatic embryos. PMID:18519247

Aberlenc-Bertossi, Frédérique; Chabrillange, Nathalie; Duval, Yves; Tregear, James

2008-08-01

304

Rhizobium lipooligosaccharides rescue a carrot somatic embryo mutant  

Microsoft Academic Search

At a nonpermissive temperature, somatic embryos of the temperature-sensitive (ts) carrot cell mutant ts11 only proceed beyond the globular embryo stage in the presence of medium conditioned by wild-type embryos. The causative component in the conditioned medium has previously been identified as a 32-kD acidic endochitinase. In search of a function for this enzyme in plant embryogenesis, several compounds that

Jong de A. J; Renze Heidstra; Herman P. Spaink; Marijke V. Hartog; Ellen A. Meijer; Theo Hendriks; Fiorella Lo Schiavo; M. Terzi; T. Bisseling; Kammen van A; Vries de S. C

1993-01-01

305

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

PubMed

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

2012-11-02

306

M-phase kinases induce phospho-dependent ubiquitination of somatic Wee1 by SCF-TrCP  

Microsoft Academic Search

Wee1, the Cdc2 inhibitory kinase, needs to be down-regulated at the onset of mitosis to ensure rapid activation of Cdc2. Previously, we have shown that human somatic Wee1 (Wee1A) is down-regulated both by protein phosphorylation and degradation, but the underlying mechanisms had not been elucidated. In the present study, we have identified the -transducin repeat-containing protein 1\\/2 (-TrCP1\\/2) F-box protein-containing

Nobumoto Watanabe; Harumi Arai; Yoshifumi Nishihara; Makoto Taniguchi; Naoko Watanabe; Tony Hunter; Hiroyuki Osada

2004-01-01

307

Ethanol-induced attenuation of oxidative stress is unable to alter mRNA expression pattern of catalase, glutathione reductase, glutathione-S-transferase (GST1A), and superoxide dismutase (SOD3) enzymes in Japanese rice fish ( Oryzias latipes) embryogenesis  

Microsoft Academic Search

Although the mechanism of ethanol toxicity during embryogenesis is unknown, our earlier studies on Japanese rice fish (Oryzias latipes) embryos indicated that the effects might be mediated through oxidative stress. In this study we have determined the oxidative stress and the mRNA content of four antioxidant enzymes (catalase, glutathione reductase, glutathione-S-transferase, and superoxide dismutase) during Japanese rice fish embryogenesis (from

Minghui Wu; Bahbak Shariat-Madar; Mona H. Haron; Mengmeng Wu; Ikhlas A. Khan; Asok K. Dasmahapatra

2011-01-01

308

The immunodominant antigen of an ultraviolet-induced regressor tumor is generated by a somatic point mutation in the DEAD box helicase p68.  

PubMed

The genetic origins of CD8+ T cell-recognized unique antigens to which mice respond when immunized with syngeneic tumor cells are unknown. The ultraviolet light-induced murine tumor 8101 expresses an H-2Kb-restricted immunodominant antigen, A, that induces cytolytic CD8+ T cells in vivo A+ 8101 cells are rejected by naive mice while A- 8101 tumor cells grow. To identify the antigen H-2Kb molecules were immunoprecipitated from A+ 8101 cells and peptides were eluted by acid. The sensitizing peptide was isolated by sequential reverse-phase HPLC and sequenced using microcapillary HPLC-triple quadruple mass spectrometry. The peptide, SNFVFAGI, matched the sequence of the DEAD box protein p68 RNA helicase except for a single amino acid substitution, caused by a single nucleotide change. This mutation was somatic since fibroblasts from the mouse of tumor origin expressed the wild-type sequence. The amino acid substitution created an anchor for binding of the mutant peptide to H-2Kb. Our results are consistent with mutant p68 being responsible for rejection of the tumor. Several functions of p68, which include nucleolar assembly and inhibition of DNA unwinding, may be mediated through its IQ domain, which was altered by the mutation. This is the first description of a somatic tumor-specific mutation in the coding region of a nucleic acid helicase. PMID:9034148

Dubey, P; Hendrickson, R C; Meredith, S C; Siegel, C T; Shabanowitz, J; Skipper, J C; Engelhard, V H; Hunt, D F; Schreiber, H

1997-02-17

309

Somatic cell hybrids for high-density mapping of chromosome 2 breakpoints in radiation-induced myeloid leukemia cell lines from inbred mice.  

PubMed

Chromosome 2 (chr 2) deletions are recurrent abnormalities in acute myeloid leukemia (AML) induced by ionizing radiation in the mouse. The localization of deletion sites has proven extremely useful in providing information on the molecular mechanisms of leukemogenesis. The models available for the study of AML are mostly represented by inbred mouse strains, in which the molecular resolution of breakpoints is problematic. In this study, we have examined five leukemic cell lines exhibiting hemizygous chr 2 loss, derived from CBA, C3H, or (C57BLxCBA/H) F1 mice in which AML had been induced by a whole-body dose of radiation. By application of a somatic cell hybridization technique, we have generated interspecific cell hybrids retaining the deleted murine chr 2 homologue. This strategy permitted a very detailed genetic analysis allowing the utilization of any genetic marker on chr 2 without a requirement for polymorphism. Somatic cell hybrid clones were subjected to a high-density polymerase chain reaction-based microsatellite screening using 62-106 informative markers for each cell line. Detailed maps accurately defining chr 2 breakpoints were obtained. The identification of critical breakpoint markers allowed the construction of partial yeast artificial chromosome contigs across chr 2 breakpoints. These maps represent an essential resource for cloning of the breakpoint regions. PMID:10708484

Pazzaglia, S; Pariset, L; Rebessi, S; Saran, A; Coppola, M; Covelli, V; Moody, J; Bouffler, S; Cox, R; Silver, A

2000-03-01

310

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.

2012-01-01

311

Somatic cell-induced hyperacetylation, but not hypomethylation, positively and reversibly affects the efficiency of in vitro cloned blastocyst production in cattle.  

PubMed

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; Nasr-Esfahani, Mohammad Hossein

2011-09-15

312

Characterization of Cyclops kolensis inter-simple sequence repeats in germline and postdiminution somatic cells  

Microsoft Academic Search

337 Chromatin diminution is programmed elimination of a part of the genome from presumptive somatic cells during early embryogenesis of some animal species. Chromatin diminution was described for a fairly small number of species of different groups of animals, such as ascarides, myxines, dipterans, Cyclops , and protozoans [2, 3, 6, 8, 10, 13, 14]. Although a great variety of

M. V. Zagoskin; A. K. Grishanin; A. L. Korolev; M. V. Palenko; D. V. Mukha

2008-01-01

313

INFLUENCE OF MEDIA COMPONENTS AND PH ON SOMATIC EMBRYO INDUCTION IN THREE GENOTYPES OF SOYBEAN  

Technology Transfer Automated Retrieval System (TEKTRAN)

The influence of media components on the initiation of somatic embryogenesis in three genotypes of soybean was investigated. The following genotypes were used: Iroquois, Macon, and Savoy. Media modifications included sucrose concentration, type and concentration of auxin at two pH levels, and pH l...

314

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

Microsoft Academic Search

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

Charles H. Michler; R. Daniel Lineberger

1987-01-01

315

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...

316

Dendritic versus somatic resonance  

Microsoft Academic Search

Here, we investigate to what extent and under which circumstances cells with dendritic resonance may be misclassified as nonresonant by somatic measurement of resonance properties. We use simple conductance-based multicompartmental models to analyze the effect of dendritic resonance on somatic input (and hence resonance estimates based on somatic recordings). We find that indeed, even a strong dendritic resonance may not

Ekaterina A Zhuchkova; Susanne Schreiber

2011-01-01

317

The c-myc and PyMT oncogenes induce different tumor types in a somatic mouse model for pancreatic cancer.  

PubMed

We have generated a mouse model for pancreatic cancer through the somatic delivery of oncogene-bearing avian retroviruses to mice that express TVA, the receptor for avian leukosis sarcoma virus subgroup A (ALSV-A), under the control of the elastase promoter. Delivery of ALSV-A-based RCAS vectors encoding either mouse polyoma virus middle T antigen (PyMT) or c-Myc to elastase-tv-a transgenic, Ink4a/Arf null mice induced the formation of pancreatic tumors. RCAS-PyMT induced pancreatic tumors with the histologic features of acinar or ductal carcinomas. The induced pancreatic lesions express Pdx1, a marker for pancreas progenitor cells, and many tumors express markers for both exocrine and endocrine cell lineages, suggesting that the tumors may be derived from progenitor cells. In contrast, RCAS-c-myc induced endocrine tumors exclusively, as determined by histology and detection of differentiation markers. Thus, specific oncogenes can induce the formation of different pancreatic tumor types in a single transgenic line, most likely from one or more types of multipotential progenitor cells. Our model appears to be useful for elucidating the genetic alterations, target cells, and signaling pathways that are important in the genesis of different types of pancreatic cancer. PMID:14681205

Lewis, Brian C; Klimstra, David S; Varmus, Harold E

2003-12-17

318

The c-myc and PyMT oncogenes induce different tumor types in a somatic mouse model for pancreatic cancer  

PubMed Central

We have generated a mouse model for pancreatic cancer through the somatic delivery of oncogene-bearing avian retroviruses to mice that express TVA, the receptor for avian leukosis sarcoma virus subgroup A (ALSV-A), under the control of the elastase promoter. Delivery of ALSV-A-based RCAS vectors encoding either mouse polyoma virus middle T antigen (PyMT) or c-Myc to elastase-tv-a transgenic, Ink4a/Arf null mice induced the formation of pancreatic tumors. RCAS-PyMT induced pancreatic tumors with the histologic features of acinar or ductal carcinomas. The induced pancreatic lesions express Pdx1, a marker for pancreas progenitor cells, and many tumors express markers for both exocrine and endocrine cell lineages, suggesting that the tumors may be derived from progenitor cells. In contrast, RCAS-c-myc induced endocrine tumors exclusively, as determined by histology and detection of differentiation markers. Thus, specific oncogenes can induce the formation of different pancreatic tumor types in a single transgenic line, most likely from one or more types of multipotential progenitor cells. Our model appears to be useful for elucidating the genetic alterations, target cells, and signaling pathways that are important in the genesis of different types of pancreatic cancer.

Lewis, Brian C.; Klimstra, David S.; Varmus, Harold E.

2003-01-01

319

High-frequency embryogenesis, regeneration of broccoli ( Brassica oleracea var. italica) and analysis of genetic stability by RAPD  

Microsoft Academic Search

High-frequency somatic embryogenesis and shoot regeneration of broccoli (Brassica oleracea var. italica) were achieved. Cotyledon and hypocotyl explants from four varieties of broccoli were cultured on MS and modified MS media (mMS, supplemented with PG-96 organic components) with different combinations of growth regulator. The effects of genotypes, different explants, growth regulator combinations, organic components and AgNO3 on induction of calli

Ying Qin; Hong-Ling Li; Yang-Dong Guo

2007-01-01

320

Thidiazuron-induced morphogenetic response in petiole cultures of Pelargonium x hortorum and Pelargonium x domesticum and its histological analysis.  

PubMed

The possibility of inducing somatic embryogenesis in petiole cultures of two cultivars of Pelargonium x hortorum and of one cultivar of Pelargonium x domesticum using thidiazuron (TDZ) was investigated. Petioles were cultivated on a modified Murashige and Skoog medium with different concentrations and application periods of TDZ. Regeneration was achieved with all TDZ treatments for all cultivars and was highly variable. Shoots of different shapes and somatic embryo-like structures were observed. Histological examination revealed that no somatic embryos were formed, and regenerants had to be classified as shoots and shoot-like or leaf-like structures. The importance of these results on the classification of regeneration induced by TDZ in these species and on the propagation of these pelargoniums is discussed. PMID:15300403

Haensch, K-T

2004-08-05

321

Genetic Regulatory Networks in Embryogenesis and Evolution.  

National Technical Information Service (NTIS)

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...

1998-01-01

322

Characterization and expression pattern analysis of DcNAC gene in somatic embryos of Dendrobium candidum Wall Ex Lindl  

Microsoft Academic Search

The plant-specific “no apical meristem” genes are transcription factors that play diverse roles in plant development and stress\\u000a responses. However, whether the gene family is also involved in somatic embryogenesis remains unknown, and no NAC family genes\\u000a have been identified from orchid species. Here, we cloned and characterized a new member of NAC family from somatic embryos\\u000a of Dendrobium candidum.

Peng Zhao; Wanjun Wang; Mengxiang Sun

323

Demecolcine- and nocodazole-induced enucleation in mouse and goat oocytes for the preparation of recipient cytoplasts in somatic cell nuclear transfer procedures.  

PubMed

Treatment of pre-activated oocytes with demecolcine (DEM) has been shown to induce the extrusion of all oocyte chromosomes within the second polar body (PB2). However, induced enucleation (IE) rates are generally low and the competence of these cytoplasts to support embryonic development following somatic cell nuclear transfer (SCNT) is impaired. Here, we explored whether short treatments with DEM or another antimitotic, nocodazole (NOC), improve IE efficiency, and determined the most appropriate timing for nuclear transfer in the cytoplasts produced. We show, for the first time, that IE can be accomplished in mouse and goat oocytes using NOC and that short treatments with DEM or NOC result in similar IE rates, which proved to be strain- and species-specific. Because enucleation induced by both antimitotic drugs is reversible, the IE protocol was combined with the mechanical aspiration of PB2s to increase permanent enucleation rates in mouse oocytes. None of the cloned mouse embryos produced from the resultant cytoplasts developed to the blastocyst stage. However, when they were reconstructed prior to the activation and antimitotic treatment, their in vitro embryonic development was similar to that of cloned embryos produced from mechanically-enucleated oocytes. PMID:21074837

Costa-Borges, Nuno; Paramio, Maria Teresa; Santaló, Josep; Ibáńez, Elena

2010-11-12

324

Bovine somatic cell nuclear transfer.  

PubMed

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

Ross, Pablo J; Cibelli, Jose B

2010-01-01

325

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

PubMed

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

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

2013-04-06

326

Stress induces plant somatic cells to acquire some features of stem cells accompanied by selective chromatin reorganization.  

PubMed

Background: Previous data suggested that senescing cells or cells exposed to acute stress may acquire stem cell properties characterized by open chromatin conformation and by promiscuous expression of transcription factor genes. To further explore the link between stress response and dedifferentiation, we generated transgenic plants in which a reporter AtMBD6-GFP is controlled by a meristem-specific promoter derived from the ANAC2 gene together with the analysis of chromatin conformation. Results: We found that ANAC2 promoter is essentially active in the shoot and the root apical meristems including leaf primordia. ANAC2 was activated in mature leaves following exposure to various stress conditions including protoplasting and dark. This activity was associated with decondensation of pericentric but not of centromeric chromatin. Using epigenetic mutants, ddm1 and kyp/suvh4, we found that compaction at centromeric chromatin persists despite a significant reduction in DNA and histone methylation. Conclusions: Our results suggest that extreme environmental signals trigger plant somatic cells to acquire stem cell properties before assuming a new cell fate. Results also pointed to distinct mechanisms involved in controlling chromatin compaction at chromocenter and that compaction of centromeric chromatin may not be dependent on epigenetic means driven by DDM1 and KYP/SUVH4 chromatin modifier proteins. Developmental Dynamics, 242:1121-1133, 2013. © 2013 Wiley Periodicals, Inc. PMID:23798027

Florentin, Assa; Damri, Meytal; Grafi, Gideon

2013-07-24

327

Influence of Media Components and pH on Somatic Embryo Induction in Three Genotypes of Soybean  

Microsoft Academic Search

The influence of media components on the initiation of somatic embryogenesis in three genotypes of soybean was investigated. The following genotypes were used: Iroquois, Macon, and Savoy. Media modifications included sucrose concentration, type and concentration of auxin at two pH levels, and pH level independently. Immature cotyledons were used as the source of explant. Cotyledons were placed on a medium

Nicolle Hofmann; Randall L. Nelson; Schuyler S. Korban

2004-01-01

328

Stimulation of Activin A/Nodal signaling is insufficient to induce definitive endoderm formation of cord blood-derived unrestricted somatic stem cells  

PubMed Central

Introduction Unrestricted somatic stem cells (USSC) derived from umbilical cord blood are an attractive alternative to human embryonic stem cells (hESC) for cellular therapy. USSC are capable of forming cells representative of all three germ line layers. The aim of this study was to determine the potential of USSC to form definitive endoderm following induction with Activin A, a protein known to specify definitive endoderm formation of hESC. Methods USSC were cultured for (1) three days with or without 100 ng/ml Activin A in either serum-free, low-serum or serum-containing media, (2) three days with or without 100 ng/ml Activin A in combination with 10 ng/ml FGF4 in pre-induction medium, or (3) four days with or without small molecules Induce Definitive Endoderm (IDE1, 100 nM; IDE2, 200 nM) in serum-free media. Formation of definitive endoderm was assessed using RT-PCR for gene markers of endoderm (Sox17, FOXA2 and TTF1) and lung epithelium (surfactant protein C; SPC) and cystic fibrosis transmembrane conductance regulator; CFTR). The differentiation capacity of Activin A treated USSC was also assessed. Results Activin A or IDE1/2 induced formation of Sox17+ definitive endoderm from hESC but not from USSC. Activin A treated USSC retained their capacity to form cells of the ectoderm (nerve), mesoderm (bone) and endoderm (lung). Activin A in combination with FGF4 did not induce formation of Sox17+ definitive endoderm from USSC. USSC express both Activin A receptor subunits at the mRNA and protein level, indicating that these cells are capable of binding Activin A. Conclusions Stimulation of the Nodal signaling pathway with Activin A or IDE1/2 is insufficient to induce definitive endoderm formation from USSC, indicating that USSC differ in their stem cell potential from hESC.

2011-01-01

329

(-)Pentazocine induces visceral chemical antinociception, but not thermal, mechanical, or somatic chemical antinociception, in ?-opioid receptor knockout mice  

Microsoft Academic Search

Background  (-)-Pentazocine has been hypothesized to induce analgesia via the ?-opioid (KOP) receptor, although the involvement of other\\u000a opioid receptor subtypes in the effects of pentazocine remains unknown. In this study, we investigated the role of the ?-opioid\\u000a (MOP) receptor in thermal, mechanical, and chemical antinociception induced by (-)-pentazocine using MOP receptor knockout\\u000a (MOP-KO) mice.\\u000a \\u000a \\u000a \\u000a \\u000a Results  (-)-Pentazocine-induced thermal antinociception, assessed by the

Soichiro Ide; Masabumi Minami; George R Uhl; Masamichi Satoh; Ichiro Sora; Kazutaka Ikeda

2011-01-01

330

Regulation of Specific Functions of Glial Cells in Somatic Hybrids, II. Control of Inducibility of Glycerol-3-Phosphate Dehydrogenase  

PubMed Central

Glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) is induced when glial cells are exposed to hydrocortisone in vitro. In contrast, the enzyme activity in fibroblasts is not affected by the steroid. In an attempt to elucidate the mechanisms controlling inducibility, hybrids between glial cells and fibroblasts were studied. It was found that the activity of the enzyme does not increase when the hybrids are exposed to hydrocortisone. It was also shown that inducibility and the noninduced activity of enzyme are controlled independently. Comparisons of S-100 and glycerol phosphate dehydrogenase activity in the hybrids suggest that all the specialized functions characteristics of glial cells are not coordinately controlled.

Davidson, Richard L.; Benda, Philippe

1970-01-01

331

Targeting of somatic hypermutation  

Microsoft Academic Search

Somatic hypermutation (SHM) introduces mutations in the variable region of immunoglobulin genes at a rate of ?10?3 mutations per base pair per cell division, which is 106-fold higher than the spontaneous mutation rate in somatic cells. To ensure genomic integrity, SHM needs to be targeted specifically to immunoglobulin genes. The rare mistargeting of SHM can result in mutations and translocations

Valerie H. Odegard; David G. Schatz

2006-01-01

332

Somatic cell genetics  

SciTech Connect

This volume traces the major developments of somatic cell genetics via 47 critical papers on somatic cell hybridization, gene transfer, and mutant mammalian cells. Recognized authorities emphasize the importance of applying the combined approach of cell genetics and recombinant DNA to questions of developments, regulations, and growth of both normal and tumor cells.

Davidson, R.L.

1984-01-01

333

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

334

Rapid and efficient reprogramming of somatic cells to induced pluripotent stem cells by retinoic acid receptor gamma and liver receptor homolog 1.  

PubMed

Somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) by expressing four transcription factors: Oct4, Sox2, Klf4, and c-Myc. Here we report that enhancing RA signaling by expressing RA receptors (RARs) or by RA agonists profoundly promoted reprogramming, but inhibiting it using a RAR-? dominant-negative form completely blocked it. Coexpressing Rarg (RAR-?) and Lrh-1 (liver receptor homologue 1; Nr5a2) with the four factors greatly accelerated reprogramming so that reprogramming of mouse embryonic fibroblast cells to ground-state iPSCs requires only 4 d induction of these six factors. The six-factor combination readily reprogrammed primary human neonatal and adult fibroblast cells to exogenous factor-independent iPSCs, which resembled ground-state mouse ES cells in growth properties, gene expression, and signaling dependency. Our findings demonstrate that signaling through RARs has critical roles in molecular reprogramming and that the synergistic interaction between Rarg and Lrh1 directs reprogramming toward ground-state pluripotency. The human iPSCs described here should facilitate functional analysis of the human genome. PMID:21990348

Wang, Wei; Yang, Jian; Liu, Hui; Lu, Dong; Chen, Xiongfeng; Zenonos, Zenon; Campos, Lia S; Rad, Roland; Guo, Ge; Zhang, Shujun; Bradley, Allan; Liu, Pentao

2011-10-11

335

Prolonged interval between fusion and activation impairs embryonic development by inducing chromosome scattering and nuclear aneuploidy in pig somatic cell nuclear transfer.  

PubMed

The aim of the present study was to examine the effect of various intervals between electrofusion and activation (FA interval) on the nuclear remodelling and development of somatic cell nuclear transfer (SCNT) embryos in pigs. Reconstructed oocytes were activated at 0 (simultaneous fusion and activation; SFA), 1, 2 and 3 h (delayed activation) after electrofusion; these groups were designated as DA1, DA2 and DA3, respectively. When oocyte nuclear status was examined at 0.5, 1, 2 and 3 h after electrofusion, the incidence of chromosome scattering was increased (P < 0.01) as the FA interval was extended (0.0%, 12.0%, 77.3% and 78.0%, respectively). Extending the FA interval led to an increase (P < 0.01) in the percentage of oocytes containing multiple (>or=3) pseudopronuclei (PPN) (0.0% of SFA; 5.3% of DA1; 21.7% of DA2; and 33.5% of DA3). The development of SCNT embryos to the blastocyst stage was decreased (P < 0.05) in DA2 (5.7%) and DA3 (5.0%) compared with SFA (18.1%) and DA1 (19.5%). Our results demonstrate that extending the FA interval impairs the development of SCNT pig embryos by inducing chromosome scattering and the formation of multiple PPN, which may result in increased nuclear aneuploidy. PMID:20591332

You, Jinyoung; Song, Kilyoung; Lee, Eunsong

2010-01-01

336

Influence of growth regulators on callogenesis and somatic embryo development in date palm (Phoenix dactylifera L.) Sahelian cultivars.  

PubMed

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

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

2012-05-02

337

Human somatic PTPN11 mutations induce hematopoietic-cell hypersensitivity to granulocyte-macrophage colony-stimulating factor  

Microsoft Academic Search

Juvenile myelomonocytic leukemia (JMML) is a lethal disease of young children charac- terized by hypersensitivity of hematopoietic progenitors to granulocyte-macrophage colony-stimulating factor (GM-CSF). Muta- tions in PTPN11, which encodes the protein tyrosine phosphatase Shp-2, are common in JMML. We hypothesized that PTPN11 mutations induce hypersensitivity of hema- topoietic progenitors to GM-CSF and confer increased GM-CSF-stimulated phospho- extracellular signal-regulated kinase (Erk)

Rebecca J. Chan; Melissa B. Leedy; Veerendra Munugalavadla; Cara S. Voorhorst; Yanjun Li; Menggang Yu; Reuben Kapur

2005-01-01

338

I{sup 131} therapy induces persistent radiation-dose dependent increases in glycophorin a locus somatic mutations in bone marrow stem cells  

SciTech Connect

Patients with thyroid diseases treated with I{sup 131} receive known sub-acute marrow exposures to ionizing radiation of {approximately}2 to >200 cGy. Time-series sampling of peripheral blood from these patients, assayed for the frequency of erythrocytes expressing glycophorin A (GPA) allele-loss variant phenotypes, demonstrates the induction, accumulation, and long-term persistence of radiation-induced in vivo somatic mutations at this locus in erythroid marrow progenitor cells. Initial dosimetry and assay data from 5 patients yielded a linear GPA dose response of {approximately}6.5 induced variants/10{sup 6} cells/Gy which is 1/3 to 1/4 of that previously observed for Hiroshima A-bomb survivors and individuals exposed at the Chernobyl nuclear reactor and Goiania Cs{sup 137} source accidents who predominantly received external exposures to ionizing radiation. The lower slope of the dose response observed in the I{sup 131} treated patients may reflect a reduced biological effectiveness of this exposure due to differences in the energy spectra of the {gamma} radiation, internal versus external exposure, and/or protracted versus acute dose rate effects. Ongoing studies of I{sup 131} treated patients are designed to define the shape of the low dose response and limit of sensitivity of the GPA assay; parameters that are required for the application of the assay as a quantitative cumulative radiation biodosimeter in medical, occupational, and accidental exposure settings. This biodosimetric analysis of patients receiving very similar marrow exposures will also permit an assessment of the inter-individual variability in biological response to ionizing radiation.

Bigbee, W.L.; Grant, S.G. [Univ. of Pittsburgh, PA (United States); Jensen, R.H. [Univ. of California, San Francisco, CA (United States); Langlois, R.G. [Lawrence Livermore National Lab., CA (United States); Reynolds, J. [National Institutes of Health, Bethesda, MD (United States); Robbins, J. [National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD (United States)

1995-11-01

339

Early Zebrafish Embryogenesis Is Susceptible to Developmental TDCPP Exposure  

PubMed Central

Background: Chlorinated phosphate esters (CPEs) are widely used as additive flame retardants for low-density polyurethane foams and have frequently been detected at elevated concentrations within indoor environmental media. Objectives: To begin characterizing the potential toxicity of CPEs on early vertebrate development, we examined the developmental toxicity of four CPEs used in polyurethane foam: tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and 2,2-bis(chloromethyl)propane-1,3-diyl tetrakis(2-chlorethyl) bis(phosphate) (V6). Methods: Using zebrafish as a model for vertebrate embryogenesis, we first screened the potential teratogenic effects of TDCPP, TCEP, TCPP, and V6 using a developmental toxicity assay. Based on these results, we focused on identification of susceptible windows of developmental TDCPP exposure as well as evaluation of uptake and elimination of TDCPP and bis(1,3-dichloro-2-propyl)phosphate (BDCPP, the primary metabolite) within whole embryos. Finally, because TDCPP-specific genotoxicity assays have, for the most part, been negative in vivo and because zygotic genome remethylation is a key biological event during cleavage, we investigated whether TDCPP altered the status of zygotic genome methylation during early zebrafish embryogenesis. Results: Overall, our findings suggest that the cleavage period during zebrafish embryogenesis is susceptible to TDCPP-induced delays in remethylation of the zygotic genome, a mechanism that may be associated with enhanced developmental toxicity following initiation of TDCPP exposure at the start of cleavage. Conclusions: Our results suggest that further research is needed to better understand the effects of a widely used and detected CPE within susceptible windows of early vertebrate development.

McGee, Sean P.; Cooper, Ellen M.; Stapleton, Heather M.

2012-01-01

340

Human somatic PTPN11 mutations induce hematopoietic-cell hypersensitivity to granulocyte-macrophage colony-stimulating factor  

PubMed Central

Juvenile myelomonocytic leukemia (JMML) is a lethal disease of young children characterized by hypersensitivity of hematopoietic progenitors to granulocyte-macrophage colony-stimulating factor (GM-CSF). Mutations in PTPN11, which encodes the protein tyrosine phosphatase Shp-2, are common in JMML. We hypothesized that PTPN11 mutations induce hypersensitivity of hematopoietic progenitors to GM-CSF and confer increased GM-CSF–stimulated phospho–extracellular signal-regulated kinase (Erk) levels. To test this hypothesis, the wild-type (WT) and 3 mutant Ptpn11 cDNAs (E76K, D61V, and D61Y) were transduced into murine bone marrow cells to examine GM-CSF–stimulated granulocyte-macrophage colony-forming unit (CFU-GM) growth, macrophage progenitor proliferation, and activation of the Ras signaling pathway. Expression of the Shp-2 mutants induced progenitor cell hypersensitivity to GM-CSF compared with cells transduced with vector alone or WT Shp-2. Macrophage progenitors expressing the Shp-2 mutants displayed both basal and GM-CSF–stimulated hyperproliferation compared with cells transduced with vector alone or WT Shp-2. Consistently, macrophage progenitors transduced with the Shp-2 mutants demonstrated constitutively elevated phospho-Erk levels and sustained activation of phospho-Erk following GM-CSF stimulation compared with vector alone or WT Shp-2. These data support the hypothesis that PTPN11 mutations induce hematopoietic progenitor hypersensitivity to GM-CSF due to hyperactivation of the Ras signaling axis and provide a basis for the GM-CSF signaling pathway as a target for rational drug design in JMML.

Chan, Rebecca J.; Leedy, Melissa B.; Munugalavadla, Veerendra; Voorhorst, Cara S.; Li, Yanjun; Yu, Menggang; Kapur, Reuben

2005-01-01

341

A germline restricted, highly repetitive DNA sequence in Paramyxineatami : an interspecifically conserved, but somatically eliminated, element  

Microsoft Academic Search

In some species of hagfish, the phenomenon of chromosome elimination occurs during embryogenesis. However, only two repetitive\\u000a DNA families are known to be represented in chromosomes that are eliminated from somatic cells of the Japanese hagfish Eptatretus okinoseanus. Using molecular analyses, another germ line-restricted, highly repetitive DNA family has been detected in another Japanese\\u000a hagfish, Paramyxine atami. The repeat unit

S. Kubota; T. Ishibashi; S. Kohno

1997-01-01

342

Differential proteomic analysis of developmental stages of Acca sellowiana somatic embryos  

Microsoft Academic Search

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

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

2009-01-01

343

SEM Study on Early Stages of Oil Palm (Elaeis guineensis Jacq.) Somatic Embryos  

Microsoft Academic Search

Oil palm (Elaeis guineensis Jacq.) is a plant with highest productivity of oil among others oil-producing plants with total product per year is 5-6 ton\\/ha. Micropropagation of oil palm by somatic embryogenesis has several advantages: homogenous plants, higher production of fresh fruit bunches and larger amount of high quality seeds in a relatively shorter time. Oil palm 635 clone (15

Totik Sri Mariani

344

The somatic patient.  

PubMed

A significant proportion of patients seen in the Emergency Department will present with somatic complaints for which there is no apparent physiologic cause. Such patients may be divided into two broad categories: (1) those with symptoms and signs consciously synthesized by the patient, either for obvious secondary gain (malingering) or as a result of more subtle and complex motivations (factitious disorders); and (2) those patients with symptoms that are the unconscious expression of psychological stress (somatoform disorders). The somatoform disorders include (1) somatization disorder (characterized by a chronic history of numerous and widely divergent somatic complaints), (2) psychogenic pain disorder (somatization expressed in terms of persistent pain), (3) hypochondriasis (a conviction that one is diseased and disabled in conjunction with a well-focused constellation of supporting symptoms), and (4) conversion disorder (a single, usually nonpainful neurologic symptom, often with identifiable coping value for the patient). The first three disorders have been aggregately termed the "common somatization syndrome." Management of the somatically focused patient includes the communication of a caring attitude to the patient in conjunction with a cautious and diligent search for treatable medical or psychiatric illness. Resocialization and development of patient links with ongoing, nurturing nonmedical as well as medical support systems is of benefit. PMID:2001663

Purcell, T B

1991-02-01

345

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

346

Satellite 2 demethylation induced by 5-azacytidine is associated with missegregation of chromosomes 1 and 16 in human somatic cells.  

PubMed

Satellite sequences are an important part of the pericentromeric regions in mammalian genomes; they play a relevant role in chromosome stability and DNA hypomethylation of these sequences has been reported in ICF syndrome and in some cancers that are closely associated with chromosomal abnormalities. Epigenetic modifications of satellite sequences and their consequences have not been extensively studied in human cells. In the present work, we evaluated satellite 2 methylation patterns in human lymphocytes exposed to 5-azacytidine (5-azaC) and assessed the relationship between these patterns and chromosome missegregation. Human lymphocytes were exposed to 10?M 5-azaC for 24, 48, and 72h. Segregation errors were evaluated in binucleate cells using FISH against pericentromeric regions of chromosomes 1, 9, and 16. DNA methylation patterns were evaluated by immunodetection, and by bisulfite plus urea conversion and sequencing. We have identified that 5-azaC induced missegregation of chromosomes 1 and 16, which have highly methylated satellite 2, after 72h of exposure. Chromosome methylation patterns showed a notable decrease in pericentromeric methylation. Bisulfite conversion and sequencing analysis demonstrated demethylation of satellite 2 associated to 5-azaC exposure, principally after 72h of treatment. This change occurred in a non-specific pattern. Our study demonstrates an association between loss of satellite 2 DNA methylation and chromosome loss in human lymphocytes. PMID:22032830

Prada, Diddier; González, Rodrigo; Sánchez, Lisandro; Castro, Clementina; Fabián, Eunice; Herrera, Luis A

2011-10-20

347

Activation of a c-K-ras oncogene by somatic mutation in mouse lymphomas induced by gamma radiation  

SciTech Connect

Mouse tumors induced by gamma radiation are a useful model system for oncogenesis. DNA from such tumors contains an activated K-ras oncogene that can transform NIH 3T3 cells. This report describes the cloning of a fragment of the mouse K-ras oncogene containing the first exon from both a transformant in rat-2 cells and the brain of the same mouse that developed the tumor. Hybrid constructs containing one of the two pieces were made and only the plasmid including the first exon from the transformant gave rise to foci in NIH 3T3 cells. There was only a single base difference (G----A) in the exonic sequence, which changed glycine to aspartic acid in the transformant. By use of a synthetic oligonucleotide the presence of the mutation was demonstrated in the original tumor, ruling out modifications during DNA-mediated gene transfer and indicating that the alteration was present in the thymic lymphoma but absent from other nonmalignant tissue. The results are compatible with gamma radiation being a source of point mutations.

Guerrero, I.; Villasante, A.; Corces, V.; Pellicer, A.

1984-09-14

348

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.

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

2011-01-01

349

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.

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

350

Transglutaminase (TG) involvement in early embryogenesis  

SciTech Connect

Transglutaminase (TG) has been examined in different stages of preimplantation mouse embryogenesis. The specific activity of this enzyme in the soluble cellular fraction increases 2-fold from 2-cell embryos to 8-cell morulae and 4-fold from 2-cell embryos to blastocyst. The same developmental profile was seen when either N,N-dimethylcasein or endogenous substrates were used in the TG assay. Using high-speed supernatants from different stage embryos as a source of enzyme and (/sup 3/H)putrescine as acyl acceptor, the major acyl donor components were tubulin and a high molecular weight (HMW) cross-linkage product, as assessed by electrophoresis and immunoblotting. When either assembled or monomeric cytoskeleton proteins were compared as subtrates, microtubules were the best acyl donors. These studies indicate that TG activity is modulated during the changing demands of blastomeres for microtubule cytoskeleton in early embryogenesis.

Maccioni, R.B.; Arechaga, J.

1986-11-01

351

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

352

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

353

Somatic cell nuclear transfer  

Microsoft Academic Search

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

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

2002-01-01

354

Transcript Profiling and Identification of Molecular Markers for Early Microspore Embryogenesis in Brassica napus1[W][OA  

PubMed Central

Isolated microspores of Brassica napus are developmentally programmed to form gametes; however, microspores can be reprogrammed through stress treatments to undergo appropriate divisions and form embryos. We are interested in the identification and isolation of factors and genes associated with the induction and establishment of embryogenesis in isolated microspores. Standard and normalized cDNA libraries, as well as subtractive cDNA libraries, were constructed from freshly isolated microspores (0 h) and microspores cultured for 3, 5, or 7 d under embryogenesis-inducing conditions. Library comparison tools were used to identify shifts in metabolism across this time course. Detailed expressed sequence tag analyses of 3 and 5 d cultures indicate that most sequences are related to pollen-specific genes. However, semiquantitative and real-time reverse transcription-polymerase chain reaction analyses at the initial stages of embryo induction also reveal expression of embryogenesis-related genes such as BABYBOOM1, LEAFY COTYLEDON1 (LEC1), and LEC2 as early as 2 to 3 d of microspore culture. Sequencing results suggest that embryogenesis is clearly established in a subset of the microspores by 7 d of culture and that this time point is optimal for isolation of embryo-specific expressed sequence tags such as ABSCISIC ACID INSENSITIVE3, ATS1, LEC1, LEC2, and FUSCA3. Following extensive polymerase chain reaction-based expression profiling, 16 genes were identified as unequivocal molecular markers for microspore embryogenesis in B. napus. These molecular marker genes also show expression during zygotic embryogenesis, underscoring the common developmental pathways that function in zygotic and gametic embryogenesis. The quantitative expression values of several of these molecular marker genes are shown to be predictive of embryogenic potential in B. napus cultivars (e.g. ‘Topas’ DH4079, ‘Allons,’ ‘Westar,’ ‘Garrison’).

Malik, Meghna R.; Wang, Feng; Dirpaul, Joan M.; Zhou, Ning; Polowick, Patricia L.; Ferrie, Alison M.R.; Krochko, Joan E.

2007-01-01

355

The synergistic effects of vanillin on recombination predominate over its antimutagenic action in relation to MMC-induced lesions in somatic cells of Drosophila melanogaster  

Microsoft Academic Search

The wing Somatic Mutation And Recombination Test (SMART) in Drosophila melanogaster was used to study the modulating action of vanillin (VA) in combination with the alkylating agents mitomycin C (MMC), methylmethanesulphonate (MMS) and the bifunctional nitrogen mustard (HN2). Two types of treatments with VA and each of the three genotoxins were performed: chronic co-treatments of three-day-old larvae of the standard

Janine Hertzog Santos; Ulrich Graf; Maria Luiza Reguly; Heloisa Helena Rodrigues de Andrade

1999-01-01

356

Morpho-histological study of somatic embryo-like structures in hypocotyl cultures of Pelargonium x hortorum Bailey.  

PubMed

Somatic embryo-like structures were produced from the hypocotyls of ten cultivars of Pelargonium x hortorum using the protocols of Marsolais et al. (1991; Can J Bot 69:1188-1193) and Slimmon et al. (1991; Plant Cell Rep 10:587-589) and their embryonic natures evaluated. Nine cultivars responded, and 937 structures were formed. Regeneration corresponded well with published data. The somatic embryo-like structures were globular- to leaf-shaped or similar to shoots. A root pole was never visible. Histological examinations confirmed the lack of bipolarity and revealed vascular connections to the explant in the more developed structures. Therefore, these structures cannot be classified as somatic embryos. The importance of these results is discussed in terms of evaluating published protocols for the propagation of these pelargoniums by somatic embryogenesis from hypocotyls. PMID:14569413

Haensch, K-T

2003-10-21

357

Discovery of genes expressed in Hydra embryogenesis.  

PubMed

Hydra's remarkable capacity to regenerate, to proliferate asexually by budding, and to form a pattern de novo from aggregates allows studying complex cellular and molecular processes typical for embryonic development. The underlying assumption is that patterning in adult hydra tissue relies on factors and genes which are active also during early embryogenesis. Previously, we reported that in Hydra the timing of expression of conserved regulatory genes, known to be involved in adult patterning, differs greatly in adults and embryos (Fröbius, A.C., Genikhovich, G., Kürn, U., Anton-Erxleben, F. and Bosch, T.C.G., 2003. Expression of developmental genes during early embryogenesis of Hydra. Dev. Genes Evol. 213, 445-455). Here, we describe an unbiased screening strategy to identify genes that are relevant to Hydra vulgaris embryogenesis. The approach yielded two sets of differentially expressed genes: one set was expressed exclusively or nearly exclusively in the embryos, while the second set was upregulated in embryos in comparison to adult polyps. Many of the genes identified in hydra embryos had no matches in the database. Among the conserved genes upregulated in embryos is the Hydra orthologue of Embryonic Ectoderm Development (HyEED). The expression pattern of HyEED in developing embryos suggests that interstitial stem cells in Hydra originate in the endoderm. Importantly, the observations uncover previously unknown differences in genes expressed by embryos and polyps and indicate that not only the timing of expression of developmental genes but also the genetic context is different in Hydra embryos compared to adults. PMID:16337937

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

2005-12-09

358

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

359

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.

360

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

361

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

Microsoft Academic Search

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

Mohd Zahid Rizvi; Arun Kumar Kukreja; Narendra Singh Bisht

2010-01-01

362

Somatic embryogenesis and plant regeneration from immature inflorescence segments of Coix lacryma-jobi  

Microsoft Academic Search

Callus was obtained from segments of immature inflorescence of Coix lacryma-jobi cultured on N6 medium containing 1–2 mg\\/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 3–5% sucrose. Plantlets were regenerated when embryogenic calluses were transferred onto MS medium with 0.5 mg\\/l kinetin and 0.01 mg\\/l naphthaleneacetic acid (NAA). Regenerated plants had the diploid chromosome number (2n=20).

C. S. Sun; C. C. Chu

1986-01-01

363

Somatic embryogenesis and plants from zygotic embryos of coconut ( Cocos nucifera L.) in vitro  

Microsoft Academic Search

Complete plants were grown from zygotic embryos cultured on Y3 basal liquid medium supplemented with coconut milk, BA and NAA. Explants from stem, leaf and rachilla of mature coconut trees turned green and swelled on Y3 semi-solid basal media supplemented with 2,4-D, K, NAA, BA and activated charcoal. Callus was initiated in explants from the subapical regions of the stem

P. K. Gupta; S. V. Kendurkar; V. M. Kulkarni; M. V. Shirgurkar; A. F. Mascarenhas

1984-01-01

364

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

Microsoft Academic Search

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

Tina Lopes; Ana Capelo; Gina Brito; Joăo Loureiro; Conceiçăo Santos

2009-01-01

365

Turnover of cell-wall polysaccharides during somatic embryogenesis and development of celery ( Apium graveolens L.)  

Microsoft Academic Search

Non-embryogenic cells (NEC) and embryogenc cells (EC) were separated from cell clusters derived from the hypocotyl segments\\u000a of celery seedlings, which had been suspension-cultured in MS medium supplemented with 105 M 2,4-D. The EC formed globular embryos in medium without 2,4-D. The globular embryo developed through heart-shaped, torpedo\\u000a to cotyledonary embryos within 10 days. The EC and developing embryos were

Up-Dong Yeo; Jung-Yeun Han; Yong-Eui Choi; Woong-Young Soh; Naoki Nakagawa; Naoki Sakurai

1999-01-01

366

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

367

Effect of Weightlessness Conditions on the Somatic Embryogenesis in the Culture of Carrot Cells.  

National Technical Information Service (NTIS)

A carrot cell culture seeded in Petri dishes in the United States and transported to the USSR was subjected to weightlessness for 20 days during the flight of Kosmos 782. The controls were cultures placed on a centrifuge (1 g) inside the satellite and cul...

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

1977-01-01

368

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

369

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

370

In vitro axillary shoot proliferation and somatic embryogenesis of yellow pitaya Mediocactus coccineus (Salm-Dyck)  

Microsoft Academic Search

Yellow pitaya (Mediocactus coccineus) seeds were sown on Murashige and Skoog (1962) mineral salt medium. After germination, epicotyls were placed on media enriched with a combination of naphthaleneacetic acid (NAA) (0.05, 0.27 or 0.54 µM) and benzyladenine (BA) (2.2 or 4.4 µM). The apical tip was excised from half of the shoots and the other half were kept intact. Different

Rodrigo Infante

1992-01-01

371

Somatic embryogenesis and plant regeneration from isolated protoplasts of Lavatera thuringiaca  

Microsoft Academic Search

Embryogenic cell suspensions of Lavatera thuringiaca L. were established from leaf petiole and shoot regeneration was achieved when cells were plated on medium without growth regulators. We tested three methods for protoplast culture, isolated from a one-year old embryogenic cell suspension, to determine the best conditions for L. thuringiaca protoplast culture and shoot regeneration. The highest protoplast plating efficiency was

Alejandro Vazquez-Tello; Makoto Hidaka; Takeshi Uozumi

1995-01-01

372

Ultrastructural Studies on Callus Development and Somatic Embryogenesis in Zea mays L  

Microsoft Academic Search

\\u000a Plant regeneration from immature embryos may follow different pathways. First, one may distinguish between a direct and an\\u000a indirect way. The former implies the de novo development of meristems on the immature embryo from which new expiants originate.\\u000a In the case of indirect regeneration, the development of new plantlets from the expiant is interrupted by an intervening callus\\u000a phase. A

P. F. Fransz; J. H. N. Schel

1994-01-01

373

Microspore embryogenesis: assignment of genes to embryo formation and green vs. albino plant production  

Microsoft Academic Search

Plant microspores can be reprogrammed from their normal pollen development to an embryogenic route in a process termed microspore\\u000a embryogenesis or androgenesis. Stress treatment has a critical role in this process, inducing the dedifferentiation of microspores\\u000a and conditioning the following androgenic response. In this study, we have used three barley doubled haploid lines with similar\\u000a genetic background but different androgenic

M. Muńoz-Amatriaín; J. T. Svensson; A. M. Castillo; T. J. Close; M. P. Vallés

2009-01-01

374

Isolation, culture, and induction of embryogenesis in protoplasts from cell-suspensions of Atropa belladonna  

Microsoft Academic Search

Summary Protoplasts isolated from actively growing cell-suspensions ofAtropa belladonna have been induced to divide repeatedly, and to undergo embryogenesis. An optimal protoplast yield of up to 80% was obtained in 4–5 hours by treating cell-suspensions with an enzyme mixture of cellulase R 10 (1%) and macerozyme R 10 (0.5%) in 0.6 M sorbitol at 30 °C. The protoplasts cultured at

G. Gosch; Y. P. S. Bajaj; J. Reinert

1975-01-01

375

Embryogenesis and doubled haploid production from anther culture in gentian ( Gentiana triflora )  

Microsoft Academic Search

The overall goal of this study is to develop an anther culture system to produce doubled haploid (DH) lines of gentian (Gentiana triflora), an ornamental flowering plant, for use in an F1 hybrid breeding program. Embryogenesis was induced from anther cultures\\u000a incubated on half-strength modified Lichter (NLN) medium containing a high concentration of sucrose (130 g\\/l) and subjected\\u000a to heat shock

Hisako Doi; Ryo Takahashi; Takashi Hikage; Yoshihito Takahata

2010-01-01

376

Reprogramming of somatic cells.  

PubMed

Reprogramming of adult somatic cells into pluripotent stem cells may provide an attractive source of stem cells for regenerative medicine. It has emerged as an invaluable method for generating patient-specific stem cells of any cell lineage without the use of embryonic stem cells. A revolutionary study in 2006 showed that it is possible to convert adult somatic cells directly into pluripotent stem cells by using a limited number of pluripotent transcription factors and is called as iPS cells. Currently, both genomic integrating viral and nonintegrating nonviral methods are used to generate iPS cells. However, the viral-based technology poses increased risk of safety, and more studies are now focused on nonviral-based technology to obtain autologous stem cells for clinical therapy. In this review, the pros and cons of the present iPS cell technology and the future direction for the successful translation of this technology into the clinic are discussed. PMID:22917226

Rajasingh, Johnson

2012-01-01

377

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

378

Somatic mutagenesis in autoimmunity.  

PubMed

Our laboratory investigates systemic autoimmune disease in the context of mouse models of systemic lupus erythematosus (SLE). SLE is associated with high titers of serum autoantibodies of the IgG class that are predominantly directed against nuclear antigens, with pathological manifestations that are considered by many to be characteristic of an immune-complex mediated disease. In this review, we focus on the known and potential roles of somatic mutagenesis in SLE. We will argue that anti-nuclear antibodies (ANA) arise predominantly from nonautoreactive B cells that are transformed into autoreactive cells by the process of somatic hypermutation (SHM), which is normally associated with affinity maturation during the germinal center reaction. We will also discuss the role of SHM in creating antigenic peptides in the V region of the B cell receptor (BCR) and its potential to open an avenue of unregulated T cell help to autoreactive B cells. Finally, we will end this review with new experimental evidence suggesting that spontaneous somatic mutagenesis of genes that regulate B cell survival and activation is a rate-limiting causative factor in the development of ANA. PMID:23249093

Detanico, Thiago; St Clair, James B; Aviszus, Katja; Kirchenbaum, Greg; Guo, Wenzhong; Wysocki, Lawrence J

2013-01-18

379

Agronomic performance of Coffea canephora P. trees derived from large-scale somatic embryo production in liquid medium  

Microsoft Academic Search

In order to validate the propagation technology of Coffea canephoraPierre var. Robusta via somatic embryogenesis in liquid medium, the clonal fidelity of regenerated trees has been assessed\\u000a for the first time in large-scale field trials. A total of 5067 trees originating from 5- to 7-month-old embryogenic cell\\u000a suspension cultures were planted in the Philippines and in Thailand for comparing with

J. P. Ducos; R. Alenton; J. F. Reano; C. Kanchanomai; A. Deshayes; V. Pétiard

2003-01-01

380

Duplication and Diversification of the Hypoxia-Inducible IGFBP-1 Gene in Zebrafish  

PubMed Central

Background Gene duplication is the primary force of new gene evolution. Deciphering whether a pair of duplicated genes has evolved divergent functions is often challenging. The zebrafish is uniquely positioned to provide insight into the process of functional gene evolution due to its amenability to genetic and experimental manipulation and because it possess a large number of duplicated genes. Methodology/Principal Findings We report the identification and characterization of two hypoxia-inducible genes in zebrafish that are co-ortholgs of human IGF binding protein-1 (IGFBP-1). IGFBP-1 is a secreted protein that binds to IGF and modulates IGF actions in somatic growth, development, and aging. Like their human and mouse counterparts, in adult zebrafish igfbp-1a and igfbp-1b are exclusively expressed in the liver. During embryogenesis, the two genes are expressed in overlapping spatial domains but with distinct temporal patterns. While zebrafish IGFBP-1a mRNA was easily detected throughout embryogenesis, IGFBP-1b mRNA was detectable only in advanced stages. Hypoxia induces igfbp-1a expression in early embryogenesis, but induces the igfbp-1b expression later in embryogenesis. Both IGFBP-1a and -b are capable of IGF binding, but IGFBP-1b has much lower affinities for IGF-I and -II because of greater dissociation rates. Overexpression of IGFBP-1a and -1b in zebrafish embryos caused significant decreases in growth and developmental rates. When tested in cultured zebrafish embryonic cells, IGFBP-1a and -1b both inhibited IGF-1-induced cell proliferation but the activity of IGFBP-1b was significantly weaker. Conclusions/Significance These results indicate subfunction partitioning of the duplicated IGFBP-1 genes at the levels of gene expression, physiological regulation, protein structure, and biological actions. The duplicated IGFBP-1 may provide additional flexibility in fine-tuning IGF signaling activities under hypoxia and other catabolic conditions.

Kamei, Hiroyasu; Lu, Ling; Jiao, Shuang; Li, Yun; Gyrup, Claus; Laursen, Lisbeth S.; Oxvig, Claus; Zhou, Jianfeng; Duan, Cunming

2008-01-01

381

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

382

Rhizobium Lipooligosaccharides Rescue a Carrot Somatic Embryo Mutant.  

PubMed Central

At a nonpermissive temperature, somatic embryos of the temperature-sensitive (ts) carrot cell mutant ts11 only proceed beyond the globular embryo stage in the presence of medium conditioned by wild-type embryos. The causative component in the conditioned medium has previously been identified as a 32-kD acidic endochitinase. In search of a function for this enzyme in plant embryogenesis, several compounds that contain oligomers of N-acetylglucosamine were tested for their ability to promote ts11 embryo formation. Of these compounds, only the Rhizobium lipooligosaccharides or nodulation (Nod) factors were found to be effective in rescuing the formation of ts11 embryos. These results suggest that N-acetylglucosamine-containing lipooligosaccharides from bacterial origin can mimic the effect of the carrot endochitinase. This endochitinase may therefore be involved in the generation of plant analogs of the Rhizobium Nod factors.

De Jong, AJ; Heidstra, R; Spaink, HP; Hartog, MV; Meijer, EA; Hendriks, T; Schiavo, FL; Terzi, M; Bisseling, T; Van Kammen, A; De Vries, SC

1993-01-01

383

LEAFY COTYLEDON2 (LEC2) promotes embryogenic induction in somatic tissues of Arabidopsis, via YUCCA-mediated auxin biosynthesis.  

PubMed

The LEAFY COTYLEDON2 (LEC2) transcription factor with a plant-specific B3 domain plays a central role in zygotic and somatic embryogenesis (SE). LEC2 overexpression induced in planta leads to spontaneous somatic embryo formation, but impairs the embryogenic response of explants cultured in vitro under auxin treatment. The auxin-related functions of LEC2 appear during SE induction, and the aim of the present study was to gain further insights into this phenomenon. To this end, the effect of LEC2 overexpression on the morphogenic responses of Arabidopsis explants cultured in vitro under different auxin treatments was evaluated. The expression profiles of the auxin biosynthesis genes were analysed in embryogenic cultures with respect to LEC2 activity. The results showed that LEC2 overexpression severely modifies the requirement of cultured explants for an exogenous auxin concentration at a level that is effective in SE induction and suggested an increase in the auxin content in 35S::LEC2-GR transgenic explants. The assumption of an LEC2 promoted increase in endogenous auxin in cultured explants was further supported by the expression profiling of the genes involved in auxin biosynthesis. The analysis indicated that YUCCAs and TAA1, working in the IPA-YUC auxin biosynthesis pathway, are associated with SE induction, and that the expression of three YUCCA genes (YUC1, YUC4 and YUC10) is associated with LEC2 activity. The results also suggest that the IAOx-mediated auxin biosynthesis pathway involving ATR1/MYB34 and CYP79B2 does not seem to be involved in SE induction. We conclude that de novo auxin production via the tryptophan-dependent IPA-YUC auxin biosynthesis pathway is implicated in SE induction, and that LEC2 plays a key role in this mechanism. PMID:23722561

Wójcikowska, Barbara; Jaskó?a, Karolina; G?siorek, Przemys?aw; Meus, Magdalena; Nowak, Katarzyna; Gaj, Ma?gorzata D

2013-05-31

384

A graphic digital database of Drosophila embryogenesis.  

PubMed

Modern studies of the genetic control of development have increased the need for an accurate and comprehensive storage and display of gene expression data. This can be achieved in the form of an electronic graphic database of development. Here, we introduce the first steps towards a database of Drosophila embryogenesis. For each morphologically defined stage, a complete series of histological and/or optical sections are generated (optical sections are generated by laser confocal microscopy). Digitized sections are imported into a drawing program where they serve as templates to define the contours of organs and the position of individual cells. From these data, surface and point cloud models of all developmental stages are generated. Gene expression data can be entered by translating the expression domain of a given gene into the three-dimensional coordinate system of the database. PMID:7716807

Hartenstein, V; Lee, A; Toga, A W

1995-02-01

385

Nodal signalling in embryogenesis and tumourigenesis.  

PubMed

With few exceptions, most cells in adult organisms have lost the expression of stem cell-associated proteins and are instead characterized by tissue-specific gene expression and function. This cell fate specification is dictated spatially and temporally during embryogenesis. It has become increasingly apparent that the elegant and complicated process of cell specification is "undone" in cancer. This may be because cancer cells respond to their microenvironment and mutations by acquiring a more permissive, plastic epigenome, or because cancer cells arise from mutated stem cells. Regardless, these advanced cancer cells must use stem cell-associated proteins to sustain their phenotype. One such protein is Nodal, an embryonic morphogen belonging to the transforming growth factor-? (TGF-?) superfamily. First described in early developmental models, Nodal orchestrates embryogenesis by regulating a myriad of processes, including mesendoderm induction, left-right asymmetry and embryo implantation. Nodal is relatively restricted to embryonic and reproductive cell types and is thus absent from most normal adult tissues. However, recent studies focusing on a variety of malignancies have demonstrated that Nodal expression re-emerges during cancer progression. Moreover, in almost every cancer studied thus far, the acquisition of Nodal expression is associated with increased tumourigenesis, invasion and metastasis. As the list of cancers that express Nodal grows, it is essential that the scientific and medical communities fully understand how this morphogen is regulated in both normal and neoplastic conditions. Herein, we review the literature relating to normal and pathological Nodal signalling. In particular, we emphasize the role that this secreted protein plays during morphogenic events and how it signals to support stem cell maintenance and tumour progression. PMID:23291354

Quail, Daniela F; Siegers, Gabrielle M; Jewer, Michael; Postovit, Lynne-Marie

2013-01-03

386

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.

387

A partially disarmed vir helper plasmid, pKYRT1, in conjunction with 2,4-dichlorophenoxyactic acid promotes emergence of regenerable transgenic somatic embryos from immature cotyledons of soybean.  

PubMed

Agrobacterium tumefaciens strain KYRT1 harboring the virulence helper plasmid pKYRT1 induces transgenic somatic embryos (SEs) at high frequency from infected immature soybean cotyledons. KYRT1 is derived from the highly oncogenic strain Chry5. However, pKYRT1 is not completely disarmed and still contains an entire T-right (T(R)) and a portion of T-left (T(L)). In this report, binary strains, each carrying fully disarmed vir helper plasmids including pKPSF2, which is a fully disarmed version of pKYRT1, were compared to strain KYRT1 for their ability to induce transgenic SEs on immature cotyledons of soybean. Six weeks following cocultivation, histochemical GUS assays of cultured explants indicated that all fully disarmed vir helper plasmids transferred their binary T-DNA, containing a GUS-intron gene, into soybean tissues. However, none of these transformed tissues developed SEs on medium with or without 2,4-dichlorophenoxyactic acid (2,4-D). On the other hand, immature cotyledons cocultivated with strain KYRT1 exhibited high induction of transgenic SEs, but only on medium supplemented with 2,4-D. Derivatives of strain Chry5 harboring other vir helper plasmids did not induce transgenic SEs under any conditions tested, thus suggesting that the chromosomal background of KYRT1 alone was not sufficient to promote somatic embryogenesis. PCR analysis indicated that 55% of transgenic embryogenic cultures and 29% of transgenic T(0) soybean plants derived by transformation using strain KYRT1 contained T(R) from pKYRT1 in addition to the uidA gene from the binary construct. None of the transgenic tissues or T(0) plants contained T(L) DNA. These results suggest that some function coded for by T(R) of pKYRT1 influences somatic embryogenesis in conjunction with exposure of the plant tissues to 2,4-D. Since the co-transformation frequency of the undesirable T-DNA sequences from the vir helper plasmid was relatively low, the partially disarmed strain KYRT1 will likely be very useful for the production of normal transgenic plants of diverse soybean cultivars. PMID:14618322

Ko, Tae-Seok; Lee, Sangman; Farrand, Stephen K; Korban, Schuyler S

2003-11-14

388

Production of goats by somatic cell nuclear transfer.  

PubMed

In this study, we demonstrate the production of transgenic goats by nuclear transfer of fetal somatic cells. Donor karyoplasts were obtained from a primary fetal somatic cell line derived from a 40-day transgenic female fetus produced by artificial insemination of a nontransgenic adult female with semen from a transgenic male. Live offspring were produced with two nuclear transfer procedures. In one protocol, oocytes at the arrested metaphase II stage were enucleated, electrofused with donor somatic cells, and simultaneously activated. In the second protocol, activated in vivo oocytes were enucleated at the telophase II stage, electrofused with donor somatic cells, and simultaneously activated a second time to induce genome reactivation. Three healthy identical female offspring were born. Genotypic analyses confirmed that all cloned offspring were derived from the donor cell line. Analysis of the milk of one of the transgenic cloned animals showed high-level production of human antithrombin III, similar to the parental transgenic line. PMID:10331804

Baguisi, A; Behboodi, E; Melican, D T; Pollock, J S; Destrempes, M M; Cammuso, C; Williams, J L; Nims, S D; Porter, C A; Midura, P; Palacios, M J; Ayres, S L; Denniston, R S; Hayes, M L; Ziomek, C A; Meade, H M; Godke, R A; Gavin, W G; Overström, E W; Echelard, Y

1999-05-01

389

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.

Bobadilla Landey, Roberto; Cenci, Alberto; Georget, Frederic; Bertrand, Benoit; Camayo, Gloria; Dechamp, Eveline; Herrera, Juan Carlos; Santoni, Sylvain; Lashermes, Philippe; Simpson, June; Etienne, Herve

2013-01-01

390

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

391

Oak somatic and gametic embryos maturation is affected by charcoal and specific aminoacids mixture  

Microsoft Academic Search

– \\u000a \\u000a • Development of both somatic and gametic embryogenesis has many applications in clonal forestry and genetic improvement,\\u000a for instance as mass-propagation of genetically improved plants and production of pure lines through doubled-haploid plant\\u000a regeneration from gametic embryos.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • The goal of this work was to improve growth, maturation and plantlet regeneration of cork oak (Quercus suber L.) embryos

Beatriz Pintos; Jose A. Manzanera; M. Angeles Bueno

2010-01-01

392

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.

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

393

Somatic musical exposure system  

US Patent & Trademark Office Database

Somatic musical exposure system for a person, preferably in recumbent position on substantially rigid supporting means. Music emanates from an air chamber in a sound housing spaced apart from the person-supporting means. A relatively fixed frame carries the person-supporting means and also the sound housing, at least the former and optionally the latter being resiliently mounted relative to the frame and thereby partly decoupled therefrom. Such resilient mounting is preferably provided by elastomeric means intervening between the frame and the means resiliently supported thereby and extending both lengthwise and widthwise. Striplike resilient mounting means preferably extends both along peripheral edges of the person-supporting means and transversely thereof between its ends.

1992-03-24

394

Analysis of the promoter activity of late embryogenesis abundant protein genes in barley seedlings under conditions of water deficit  

Microsoft Academic Search

Promoters of the late embryogenesis abundant protein genes, HVA1s, Dhn8s and Dhn4s from barley and wsi18j and rab16Bj from rice, were analysed in barley seedlings to assess their strength and timing of induction under water deficit conditions using a transient expression system. Of the drought-inducible promoters, Dhn4s exhibited the highest activity, followed by HVA1s, wsi18j and rab16Bj. Dehydration-induced #-glucuronidase expression

F.-H. Xiao; G.-P. Xue

2001-01-01

395

Expression of developmental genes during early embryogenesis of Hydra.  

PubMed

Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early embryogenesis. Whether, however, Hydra embryogenesis is governed by the same mechanisms which are controlling adult patterning, remains to be shown. In this paper, in precisely staged Hydra embryos, we examined the expression pattern of 15 regulatory genes shown previously to play a role in adult patterning and cell differentiation. RT-PCR revealed that most of the genes examined were expressed in rather late embryonic stages. In situ hybridization, nuclear run-on experiments, and staining of nucleolar organizer region-associated proteins indicated that genes expressed in early embryos are transcribed in the engulfed "nurse cells" (endocytes). This is the first direct evidence that endocytes in Hydra not only provide nutrients to the developing oocyte but also produce maternal factors critical for embryogenesis. Our findings are an initial step towards understanding the molecular machinery controlling embryogenesis of a key group of basal metazoans and raise the possibility that in Hydra there are differences in the mechanisms controlling embryogenesis and adult patterning. PMID:12883882

Fröbius, Andreas C; Genikhovich, Gregory; Kürn, Ulrich; Anton-Erxleben, Friederike; Bosch, Thomas C G

2003-07-16

396

ER71 directs mesodermal fate decisions during embryogenesis.  

PubMed

Er71 mutant embryos are nonviable and lack hematopoietic and endothelial lineages. To further define the functional role for ER71 in cell lineage decisions, we generated genetically modified mouse models. We engineered an Er71-EYFP transgenic mouse model by fusing the 3.9 kb Er71 promoter to the EYFP reporter gene. Using FACS and transcriptional profiling, we examined the EYFP(+) population of cells in Er71 mutant and wild-type littermates. In the absence of ER71, we observed an increase in the number of EYFP-expressing cells, increased expression of the cardiac molecular program and decreased expression of the hemato-endothelial program, as compared with wild-type littermate controls. We also generated a novel Er71-Cre transgenic mouse model using the same 3.9 kb Er71 promoter. Genetic fate-mapping studies revealed that the ER71-expressing cells give rise to the hematopoietic and endothelial lineages in the wild-type background. In the absence of ER71, these cell populations contributed to alternative mesodermal lineages, including the cardiac lineage. To extend these analyses, we used an inducible embryonic stem/embryoid body system and observed that ER71 overexpression repressed cardiogenesis. Together, these studies identify ER71 as a critical regulator of mesodermal fate decisions that acts to specify the hematopoietic and endothelial lineages at the expense of cardiac lineages. This enhances our understanding of the mechanisms that govern mesodermal fate decisions early during embryogenesis. PMID:21989919

Rasmussen, Tara L; Kweon, Junghun; Diekmann, Mackenzie A; Belema-Bedada, Fikru; Song, Qingfeng; Bowlin, Kathy; Shi, Xiaozhong; Ferdous, Anwarul; Li, Tongbin; Kyba, Michael; Metzger, Joseph M; Koyano-Nakagawa, Naoko; Garry, Daniel J

2011-11-01

397

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

398

Cellular Potts Models of Fruit Fly Embryogenesis  

NASA Astrophysics Data System (ADS)

Biologists have extensively studied embryonic development in the fruit fly (Drosophila melangaster) as a model for morphogenesis. Our overall goal is to understand how the cellular rearrangements of morphogenesis are caused by the underlying forces between cells. To that end, we are developing means to replicate fruit fly embryogenesis (from cellular differentiation to dorsal closure) using cellular Potts models. Cells are described as collections of like ``spins''; and spin-spin interaction energies are used to describe the forces along cell boundaries. Using a four state (spin-type) model (three tissue types and the surrounding media) we have reproduced cell sorting as well as engulfment of a surface grouping of tissue. Cell sorting can be accomplished using only the spin-spin interaction energies with the volume components being used only for cell size management. We are currently attempting to replicate the experimentally determined geometry and dynamics of dorsal closure. This modeling will take advantage of software tools developed at Notre Dame for looking at cellular Potts models and packaged as CompuCell3D.

Rohner, Jason; Hutson, Shane

2006-11-01

399

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.

2011-01-01

400

Evolution of early embryogenesis in rhabditid nematodes  

PubMed Central

The cell biological events that guide early embryonic development occur with great precision within species but can be quite diverse across species. How these cellular processes evolve and which molecular components underlie evolutionary changes is poorly understood. To begin to address these questions, we systematically investigated early embryogenesis, from the one- to the four-cell embryo, in 34 nematode species related to C. elegans. We found 40 cell-biological characters that captured the phenotypic differences between these species. By tracing the evolutionary changes on a molecular phylogeny, we found that these characters evolved multiple times and independently of one another. Strikingly, all these phenotypes are mimicked by single-gene RNAi experiments in C. elegans. We use these comparisons to hypothesize the molecular mechanisms underlying the evolutionary changes. For example, we predict that a cell polarity module was altered during the evolution of the Protorhabditis group and show that PAR-1, a kinase localized asymmetrically in C. elegans early embryos, is symmetrically localized in the one-cell stage of Protorhabditis group species. Our genome-wide approach identifies candidate molecules—and thereby modules—associated with evolutionary changes in cell-biological phenotypes.

Brauchle, Michael; Kiontke, Karin; MacMenamin, Philip; Fitch, David H. A.; Piano, Fabio

2009-01-01

401

Predicting the regenerative capacity of conifer somatic embryogenic cultures by metabolomics.  

PubMed

Somatic embryogenesis in gymnosperms is an effective approach to clonally propagating germplasm. However, embryogenic cultures frequently lose regenerative capacity. The interactions between metabolic composition, physiological state, genotype and embryogenic capacity in Pinus taeda (loblolly pine) somatic embryogenic cultures were explored using metabolomics. A stepwise modelling procedure, using the Bayesian information criterion, generated a 47 metabolite predictive model that could explain culture productivity. The model performed extremely well in cross-validation, achieving a correlation coefficient of 0.98 between actual and predicted mature embryo production. The metabolic composition and structure of the model implied that variation in culture regenerative capacity was closely linked to the physiological transition of cultures from the proliferation phase to the maturation phase of development. The propensity of cultures to advance into this transition appears to relate to nutrient uptake and allocation in vivo, and to be associated with the tolerance and response of cultures to stress, during the proliferation phase. PMID:19906246

Robinson, Andrew R; Dauwe, Rebecca; Ukrainetz, Nicholas K; Cullis, Ian F; White, Rick; Mansfield, Shawn D

2009-12-01

402

Somatic responses in behavioral inhibition  

Microsoft Academic Search

In the present study, skin conductance responses (SCRs) were measured postdecision and prefeedback in a go\\/no-go (GNG) task\\u000a in which participants used response feedback to learn when to respond or not to respond to numeric stimuli. Like somatic markers\\u000a in gambling tasks and somatic reactions to error monitoring in choice reaction time tasks, SCR patterns distinguished between\\u000a correct and incorrect

Paul Whitney; John M. Hinson; Aaron Wirick; Heather Holben

2007-01-01

403

Stability of potato ( Solanum tuberosum L.) plants regenerated via somatic embryos, axillary bud proliferated shoots, microtubers and true potato seeds: a comparative phenotypic, cytogenetic and molecular assessment  

Microsoft Academic Search

The stability, both genetic and phenotypic, of potato (Solanum tuberosum L.) cultivar Desiree plants derived from alternative propagation methodologies has been compared. Plants obtained through\\u000a three clonal propagation routes—axillary-bud-proliferation, microtuberisation and a novel somatic embryogenesis system, and\\u000a through true potato seeds (TPS) produced by selfing were evaluated at three levels: gross phenotype and minituber yield, changes\\u000a in ploidy (measured by

Sanjeev Kumar Sharma; Glenn J. Bryan; Mark O. Winfield; Steve Millam

2007-01-01

404

[Influence of high concentration of antibodies to NGF during early embryogenesis on formation of mice behavior in postnatal period].  

PubMed

In this work the influence of high concentration of antibodies to NGF on mouse's progeny has been investigated. During immunization with NGF the highest concentrations of antibodies were created in the first and third days of pregnancy (in different groups of animals). The dependence of abnormalities of mice postnatal development on level of antibodies to NGF at different stages of early embryogenesis has been established. Increasing of abnormalities in the formation of early behavioral acts and more clinically apparent anomalies in the somatic maturation in case of maximum of antibodies on day I of pregnancy has been showed. Immune responses to NGF during early embryogenesis of mice cause lag in the formation of behavioral acts. The latter are characterized by difficulties in sensor-motor coordination of the limbs and more clinically apparent in mice with a maximum of antibodies on day 1 of embryonic development. Infantilism in developing of contacts between progeny and mothers detected in mice with immune reactions may be a sign of serious mental dysontogenesis. The accelerated development of working memory established in mice with immune response to NGF requires further study of the development of cognitive abilities in these animals. The obtained results illustrate the important regulatory role of NGF at the early stages of development of the nervous system. PMID:23072115

Rodionov, A N; Lobanov, A V; Morozov, S G; Sidiakin, A A; Anikina, O M; Gribova, I E; Rybakov, A S; Protsenko, A N; Murashev, A N; Kliushnik, T P

405

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

406

Systematic Analysis of Pleiotropy in C. elegans Early Embryogenesis  

PubMed Central

Pleiotropy refers to the phenomenon in which a single gene controls several distinct, and seemingly unrelated, phenotypic effects. We use C. elegans early embryogenesis as a model to conduct systematic studies of pleiotropy. We analyze high-throughput RNA interference (RNAi) data from C. elegans and identify “phenotypic signatures”, which are sets of cellular defects indicative of certain biological functions. By matching phenotypic profiles to our identified signatures, we assign genes with complex phenotypic profiles to multiple functional classes. Overall, we observe that pleiotropy occurs extensively among genes involved in early embryogenesis, and a small proportion of these genes are highly pleiotropic. We hypothesize that genes involved in early embryogenesis are organized into partially overlapping functional modules, and that pleiotropic genes represent “connectors” between these modules. In support of this hypothesis, we find that highly pleiotropic genes tend to reside in central positions in protein-protein interaction networks, suggesting that pleiotropic genes act as connecting points between different protein complexes or pathways.

Zou, Lihua; Sriswasdi, Sira; Ross, Brian; Missiuro, Patrycja V.; Liu, Jun; Ge, Hui

2008-01-01

407

Mechanical Cues in the Early Embryogenesis of Caenorhabditis elegans  

PubMed Central

Biochemical signaling pathways in developmental processes have been extensively studied, yet the role of mechanical cues during embryogenesis is much less explored. Here we have used selective plane illumination microscopy in combination with a simple mechanical model to quantify and rationalize cell motion during early embryogenesis of the small nematode Caenorhabditis elegans. As a result, we find that cell organization in the embryo until gastrulation is well described by a purely mechanical model that predicts cells to assume positions in which they face the least repulsive interactions from other cells and the embryo’s egg shell. Our findings therefore suggest that mechanical interactions are key for a rapid and robust cellular arrangement during early embryogenesis of C. elegans.

Fickentscher, Rolf; Struntz, Philipp; Weiss, Matthias

2013-01-01

408

Induction of somatic embryos in Arabidopsis requires local YUCCA expression mediated by the down-regulation of ethylene biosynthesis.  

PubMed

Somatic embryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results in somatic embryogenesis, the mechanisms underlying the initiation of somatic embryos (SEs) are poorly understood. In this study, we showed that YUCCAs (YUCs) encoding key enzymes in auxin biosynthesis are required for SE induction in Arabidopsis. To identify other factors mediating SE initiation, we performed transcriptional profiling and gene expression analysis. The results showed that genes involved in ethylene biosynthesis and its responses were down-regulated during SE initiation. Ethylene level decreased progressively during SE initiation, whereas treatment with the metabolic precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), or mutation of ETHYLENE-OVERPRODUCTION1 (ETO1) disrupted SE induction, suggesting that ethylene plays a role in this process. Suppression of SE induction was also observed in the constitutive triple response 1 (ctr1) mutant, in which ethylene signaling was enhanced. These results indicate that down-regulation of not only ethylene biosynthesis, but also ethylene response is critical for SE induction. We further showed that ethylene disturbed SE initiation through inhibiting YUC expression that might be involved in local auxin biosynthesis and subsequent auxin distribution. Our results provide new information on the mechanisms of hormone-regulated SE initiation. PMID:23271028

Bai, Bo; Su, Ying Hua; Yuan, Jia; Zhang, Xian Sheng

2012-12-27

409

Psychopharmacotherapy of somatic symptoms disorders.  

PubMed

Somatic symptoms are often common causes for medical consultation. The treatment of somatic symptoms disorders is complicated by lack of boundary, conceptual clarity, and overemphasis on psychosocial causation and effectiveness of psychological treatments. In clinical practice all classes of psychotropics are used to treat somatic symptoms disorder. Five principal groups of drugs such as tricyclic antidepressants (TCA), serotonin reuptake inhibitors (SSRI), serotonin and noradrenalin reuptake inhibitors (SNRI), atypical antipsychotics and herbal medication are systematically studied. The evidence indicates that all five groups are effective in a wide range of disorders. All classes of antidepressants seem to be effective against somatoform and related disorders. SSRIs are more effective against hypochondriasis and body dysmorphic disorder (BDD), and SNRIs appear to be more effective than other antidepressants when pain is the predominant symptom. Research leaves many unanswered questions regarding dosing, duration of treatment, sustainability of improvement in the long term and differential response to different class drugs. Further studies need to focus on treatments based on clinical features/psychopathology and collaborative research with other specialists in understanding the relation of somatic symptom disorders and functional somatic syndromes (FSS), and comparing psychotropics and non-psychotropics and combinations treatments. PMID:23383672

Somashekar, Bettahalasoor; Jainer, Ashok; Wuntakal, Balaji

2013-02-01

410

Microspore embryogenesis: establishment of embryo identity and pattern in culture.  

PubMed

The developmental plasticity of plants is beautifully illustrated by the competence of the immature male gametophyte to change its developmental fate from pollen to embryo development when exposed to stress treatments in culture. This process, referred to as microspore embryogenesis, is widely exploited in plant breeding, but also provides a unique system to understand totipotency and early cell fate decisions. We summarize the major concepts that have arisen from decades of cell and molecular studies on microspore embryogenesis and put these in the context of recent experiments, as well as results obtained from the study of pollen and zygotic embryo development. PMID:23852380

Soriano, Mercedes; Li, Hui; Boutilier, Kim

2013-07-14

411

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

412

Epithelial self-organization in fruit fly embryogenesis  

Microsoft Academic Search

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

M. Shane Hutson

2010-01-01

413

Expression of developmental genes during early embryogenesis of Hydra  

Microsoft Academic Search

Hydra is a classical model to study key features of embryogenesis such as axial patterning and stem cell differentiation. In contrast to other organisms where these mechanisms are active only during embryonic development, in Hydra they can be studied in adults. The underlying assumption is that the machinery governing adult patterning mimics regulatory mechanisms which are also active during early

Andreas C. Fröbius; Gregory Genikhovich; Ulrich Kürn; Friederike Anton-Erxleben; Thomas C. G. Bosch

2003-01-01

414

Comparison of reprogramming ability of mouse ES and iPS cells measured by somatic cell fusion.  

PubMed

The ectopic expression of the key transcription factors Oct4, Sox2, c-Myc, and Klf-4 have been shown to reprogram somatic cells to a pluripotent state. In turn these induced pluripotent stem (iPS) cells, like embryonic stem (ES) cells, have been shown to be able to reprogram somatic cells by cell fusion. In this study we compare the differences and similarities between ES and iPS cells measured by somatic cell fusion to somatic cells harboring an Oct4-GFP transgene. We found that iPS cells were just as potent as ES cells at reprogramming the somatic genome as measured by Oct4-GFP reactivation. The resulting ES-somatic and iPS-somatic cell hybrids were characterized for expression of key pluripotency genes, immunostaining for Oct4, SSEA-1, and the ability to differentiate into cell types representative of the three germ layers. In addition to restoring pluripotency to the somatic genome following cell fusion, the telomere maintenance mechanisms of both the ES and iPS cells were found to be dominant in the resulting ES-somatic and iPS-somatic cell hybrids, resulting in the lengthening of the somatic telomeres following cellular reprogramming. Therefore this study supports the view that iPS cells can be virtually indistinguishable from ES cells, even with regard to their reprogramming ability. PMID:21404192

Sumer, Huseyin; Nicholls, Craig; Liu, Jun; Tat, Pollyanna A; Liu, Jun-Ping; Verma, Paul J

2010-01-01

415

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

416

Somatic variation in Lolium perenne  

Microsoft Academic Search

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

Y Shimamoto; M D Hayward

1975-01-01

417

[Haldane's rule and somatic mutations].  

PubMed

Haldane's rule stating that viability and fertility in the heterogametic sex of hybrids are lower than in the homogametic sex is explained on the basis of the assumption that diploidy is aimed at protecting individuals having large body size and large genomes from somatic mutations. The presence of hemizygous sex chromosomes, which are effectively haploid in the heterogametic sex, results in the phenotypic expression of all deleterious somatic mutations arising in them. In the homogametic sex, somatic mutations that affect one out of two identical sex chromosomes are not expressed because the unaffected chromosome functions normally. Thus, the heterogametic sex is more sensitive to the harmful effect of somatic mutations. In hybrids, this difference may be critical. Consequently, when genetic distance between hybridizing species increases, the heterogametic sex of hybrids loses viability and fertility earlier than the homogametic sex, which agrees with Haldane's rule. On the basis of Haldane's rule and data on the small size of natural hybrid zones, restrictions on maximum heterozygosity compatible with viability were established. PMID:10505261

Gorshkov, V G; Makar'eva, A M

1999-06-01

418

TOWARDS NORMALIZATION OF SOYBEAN SOMATIC EMBRYO MATURATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soybean (Glycine max L. Merrill) somatic embryos have proven useful to assay seed-specific traits prior to plant recovery. The usefulness of soybean somatic embryos for the evaluation of seed-specific traits for transgenic or reverse genetics programs could be further enhanced if soybean somatic em...

419

The reverse transcriptase model of somatic hypermutation.  

PubMed Central

The evidence supporting the reverse transcriptase model of somatic hypermutation is critically reviewed. The model provides a coherent explanation for many apparently unrelated findings. We also show that the somatic hypermutation pattern in the human BCL-6 gene can be interpreted in terms of the reverse transcriptase model and the notion of feedback of somatically mutated sequences to the germline over evolutionary time.

Steele, E J; Blanden, R V

2001-01-01

420

Anxiety and somatization  

Microsoft Academic Search

Contrary to self-reports, most patients with chronic anxiety disorders exhibit increased muscle tension but not autonomic hyperarousal when at rest. Under everyday stress they tend to react with less physiological flexibility than normal controls. However, they overreact subjectively and physiologically to stimuli that are anxiety-provoking. Diminished physiological flexibility (DPF) may be caused by anxiety-induced cerebral overresponse to neutral stimuli, leading

Rudolf Hoehn-Saric

2006-01-01

421

Environmental odours and somatic complaints.  

PubMed

Two field studies in two cities in Northrhine-Westfalia were carried out in order to characterize the degree of association between environmental odour-exposure, annoyance, and somatic symptoms. In both studies, odour effects were assessed through personal interviews by means of standardised questionnaires. In the first study, the odour source was a fertilizer plant for mushroom cultivation with particularly offensive odour emissions. The distance from the source was taken to characterize the intensity of odour exposure. 250 subjects were interviewed at close, medium or remote distance from the plant. Apart from an extremely high degree of annoyance, an increasing frequency of somatic symptoms was found with increasing proximity to the odour source. Somatic symptoms were directly linked to odour exposure and additionally mediated by annoyance. In the second study (n = 322), the odour source was a pig rearing facility, and the degree of odour exposure was assessed by measuring the frequency of odour-events by means of systematic field observations. Results showed that the degree of odour-annoyance as well as the frequency of somatic symptoms increased significantly with increasing odour-exposure, although their frequency was reduced relative to the first study, and mediated by annoyance. In both studies, perceived negative health was associated with increased symptom reports, however, results for old age were inconsistent. Response tendencies and biases were controlled. Environmental odours have been shown to be associated with somatic symptoms and, may, thus, be considered as a risk factor for health and wellbeing of exposed populations, especially for vulnerable subjects with perceived negative health. PMID:10507121

Steinheider, B

1999-08-01

422

Detection of somatic mosaicism in DMD using computer-assisted laser densitometry  

SciTech Connect

Approximately two-thirds of Duchenne muscular dystrophy (DMD) patients have a deletion in the dystrophin gene located at Xp21.1. Two PCR-based multiplex systems have been developed which detect 98% of deletions in affected males. Diagnosis of carrier females requires densitometry of PCR products following gel electrophoresis to calculate dosage of specific exons. We have developed a system in which fluorescently labelled PCR products are analysed using a GENESCANNER automated fragment analyser (ABI). Dosage is determined using computer-assisted laser densitometry (CALD). Recently, we diagnosed somatic mosaicism in the mother of an affected boy using this method. PCR analysis showed that the patient had a deletion that included exons 47-51 of his dystrophin gene. CALD analysis on the patient`s 36-year-old mother revealed a 29-34% reduction in the intensity of the bands corresponding to the deleted region of the gene rather than the 50% reduction normally seen in carrier females. A skin biopsy was obtain and monoclonal fibroblast colonies were tested by CALD for the deletion. Four of the twenty colonies screened were found to be deleted while the remaining colonies had two intact copies of the gene. We conclude that this patient is a somatic mosaic for DMD and that the mutation was the result of a post-zygotic event. This is the only case of somatic mosaicism detected among 800 women from 400 DMD families tested using CALD in our laboratory. At least one other case of possible somatic mosaicism has been reported but not confirmed. Germinal mosaicism is thought to occur in approximately 10% of mothers of sporadic DMD patients. Our findings indicate that somatic mosaicism is a much rarer condition among DMD carriers, thus suggesting that mitotic mutations in the dystrophin gene are more likely to occur later in embryogenesis after differentiation of the germline.

Sutherland, J.E.; Allingham-Hawkins, D.J.; MacKenzie, J. [Hospital for Sick Children, Toronto (Canada)] [and others

1994-09-01

423

Regulation of early Xenopus embryogenesis by Smad ubiquitination regulatory factor 2  

PubMed Central

Background Smad ubiquitination regulatory factor (Smurf) 1 and 2 are E3 ubiquitin ligases originally identified as inhibitors of transforming growth factor beta signaling and are shown to modulate multiple cellular activities. The roles of Smurfs in vertebrate embryogenesis, however, are not completely understood. Results Here we investigate the function of Smurf2 during early Xenopus development. We show that distinctly from Smurf1, overexpression of Smurf2 in presumptive mesoderm interfered with mesoderm induction and caused axial defects, whereas knockdown of Smurf2 with antisense morpholino oligonucleotides resulted in expansion of the mesoderm. These results imply that Smurf2 may modulate nodal-mediated mesodermal induction. Consistently, ventral expression of Smurf2 induced a partial secondary axis with head structures. In the ectoderm, Smurf2 resembled Smurf1 in controlling neural and epidermal marker expression and influencing head formation. Smurf1, but not Smurf2, additionally affected neural tube closure. Interestingly, both Smurfs could enhance as well as repress neural crest markers, implying that they modulate their targets dynamically during neural plate border specification. Conclusion Our data demonstrate that Smurf1 and Smurf2 have overlapping and distinct functionalities during early frog embryogenesis; collectively, they regulate ectodermal and mesodermal induction and patterning to ensure normal development of Xenopus embryos.

Das, Shaonli; Chang, Chenbei

2012-01-01

424

Somatic mutation, genomic variation, and neurological disease.  

PubMed

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

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

2013-07-01

425

Identification of Spectral Modifications Occurring during Reprogramming of Somatic Cells  

PubMed Central

Recent technological advances in cell reprogramming by generation of induced pluripotent stem cells (iPSC) offer major perspectives in disease modelling and future hopes for providing novel stem cells sources in regenerative medicine. However, research on iPSC still requires refining the criteria of the pluripotency stage of these cells and exploration of their equivalent functionality to human embryonic stem cells (ESC). We report here on the use of infrared microspectroscopy to follow the spectral modification of somatic cells during the reprogramming process. We show that induced pluripotent stem cells (iPSC) adopt a chemical composition leading to a spectral signature indistinguishable from that of embryonic stem cells (ESC) and entirely different from that of the original somatic cells. Similarly, this technique allows a distinction to be made between partially and fully reprogrammed cells. We conclude that infrared microspectroscopy signature is a novel methodology to evaluate induced pluripotency and can be added to the tests currently used for this purpose.

Sandt, Christophe; Feraud, Olivier; Oudrhiri, Noufissa; Bonnet, Marie Laure; Meunier, Marie Claude; Valogne, Yannick; Bertrand, Angelina; Raphael, Martine; Griscelli, Frank; Turhan, Ali G.; Dumas, Paul; Bennaceur-Griscelli, Annelise

2012-01-01

426

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

427

Bisphenol A induces otolith malformations during vertebrate embryogenesis  

Microsoft Academic Search

BACKGROUND: The plastic monomer and plasticizer bisphenol A (BPA), used for manufacturing polycarbonate plastic and epoxy resins, is produced at over 2.5 million metric tons per year. Concerns have been raised that BPA acts as an endocrine disruptor on both developmental and reproductive processes and a large body of evidence suggests that BPA interferes with estrogen and thyroid hormone signaling.

Yann Gibert; Sana Sassi-Messai; Jean-Baptiste Fini; Laure Bernard; Daniel Zalko; Jean-Pierre Cravedi; Patrick Balaguer; Monika Andersson-Lendahl; Barbara Demeneix; Vincent Laudet

2011-01-01

428

Somatic correlates of functional enuresis  

Microsoft Academic Search

Functional enuresis is a heterogeneous group of syndromes with different aetiology and pathophysiology. The aim was to identify\\u000a specific somatic correlates of enuresis non-invasively in child psychiatric patients after exclusion of neurologic and structural\\u000a forms of incontinence. One hundred sixty-seven consecutive children, aged 5 to 10 years with day and\\/or night wetting were\\u000a examined prospectively with: urinalysis and bacteriology; ultrasonography,

A. von Gontard; B. Benden; K. Mauer-Mucke; G. Lehmkuhl

1999-01-01

429

Regulation of germ layer formation by pluripotency factors during embryogenesis  

PubMed Central

The classical pluripotency factors Oct4, Klf4, Sox2, and Nanog are required for the maintenance of pluripotency and self-renewal of embryonic stem (ES) cells and can reprogram terminally differentiated cells into a pluripotent state. Alteration in the levels of these factors in ES cells will cause differentiation into different lineages, suggesting that they are critical determinants of cell fates. These factors show dynamic expression patterns during embryogenesis, in particular in the pluripotent or multipotent cells of an early stage embryo, implying that they are involved in the cell fate decision during early embryonic development. Functions and the underlying molecular mechanisms have been extensively studied for these factors in ES cells under cultured conditions. However, this does not mean that the results also hold true for intact embryos. In the review, I have summarized and discussed the findings on the functions and the underlying mechanisms of the classical pluripotency factors during early embryogenesis, in particular during germ layer formation.

2013-01-01

430

Somatic hypotheses of war syndromes.  

PubMed

Since the end of the American Civil War, unexplained symptoms in military personnel arising after a war or peace mission have frequently been described. The pattern of symptoms is highly similar for all of the various war syndromes although the conditions of each war or peace mission are widely different. Many somatic hypotheses have been formulated to explain these syndromes; a considerable proportion of them are already outdated. In the last few years much attention has been given to Gulf War Syndrome and to unexplained symptoms of military personnel who were sent to Cambodia, Rwanda, Burundi, Zaire, or the former Yugoslavia. In this review the symptoms of war syndromes will be considered in more detail and the suggested somatic explanations will be discussed. During the last decade the following somatic causes have been suggested as possible explanations for these symptoms: (persistent) infection, abnormal immune response, administration of multiple vaccinations within a short period of time, use of malaria chemoprophylaxis, neurological abnormalities, exposure to toxicological substances and environmental factors. The various investigations performed to study these hypotheses are discussed. The fact that bias regularly occurs in the course of these investigations is pointed out. For the future, a reliable investigation of a war syndrome should be a prospective multidisciplinary study and should distinguish between causative and sustaining factors. PMID:10886303

Soetekouw, P M; de Vries, M; van Bergen, L; Galama, J M; Keyser, A; Bleijenberg, G; van der Meer, J W

2000-07-01

431

From in vitro fertilization to early embryogenesis in maize  

Microsoft Academic Search

Summary The development of in vitro fertilization methods in plants, the characterization of developmental mutants, and the adaptation of molecular biology techniques to construct cDNA libraries from minute samples, all represent important recent technical break-throughs. They allow the study of fertilization and early embryogenesis at a molecular level and considerable improvement in the under-standing of higher plant reproduction can be

C. Breton; J. E. Faure; C. Dumas

1995-01-01

432

The Genetic and Epigenetic Contributions of Sperm to Early Embryogenesis  

Microsoft Academic Search

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

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

433

Errors in Chromosome Segregation During Oogenesis and Early Embryogenesis  

Microsoft Academic Search

\\u000a Errors in chromosome segregation occurring during human oogenesis and early embryogenesis are very common. Meiotic chromosome\\u000a development during oogenesis is subdivided into three distinct phases. The crucial events, including meiotic chromosome pairing\\u000a and recombination, take place from around 11 weeks until birth. Oogenesis is then arrested until ovulation, when the first\\u000a meiotic division takes place, with the second meiotic division

Maj Hultén; Edward Smith; Joy Delhanty

434

Glucose metabolism during embryogenesis of the hard tick Boophilus microplus.  

PubMed

Glucose metabolism plays an essential role in the physiology and development of almost all living organisms. In the present study we investigated glucose metabolism during the embryogenesis of the hard tick Boophilus microplus. An increase in glucose and glycogen content during the embryonic development of B. microplus was detected and shown to be due to the high enzyme activity of both gluconeogenesis and glycolytic pathways. Glucose 6-phosphate (G-6P), formed by hexokinase, is driven mainly to pentose-phosphate pathway, producing fundamental substrates for cellular biosynthesis. We detected an increase in glucose 6-phosphate dehydrogenase and pyruvate kinase activities after embryo cellularization. Accumulation of key metabolites such as glycogen and glucose was monitored and revealed that glycogen content decreases from day 1 up to day 6, as the early events of embryogenesis take place, and increases after the formation of embryo cellular blastoderm on day 6. Glucose and guanine (a sub-product of amino acids degradation in arachnids) accumulate almost concomitantly. The activity of phosphoenolpyruvate carboxykinase was increased after embryo cellularization. Taken together these data indicate that glycogen and glucose, formed during B. microplus embryogenesis after blastoderm formation, are produced by intense gluconeogenesis. PMID:16904922

Moraes, Jorge; Galina, Antônio; Alvarenga, Patrícia H; Rezende, Gustavo Lazzaro; Masuda, Aoi; da Silva Vaz, Itabajara; Logullo, Carlos

2006-05-23

435

Visualizing enveloping layer glycans during zebrafish early embryogenesis  

PubMed Central

Developmental events can be monitored at the cellular and molecular levels by using noninvasive imaging techniques. Among the biomolecules that might be targeted for imaging analysis, glycans occupy a privileged position by virtue of their primary location on the cell surface. We previously described a chemical method to image glycans during zebrafish larval development; however, we were unable to detect glycans during the first 24 hours of embryogenesis, a very dynamic period in development. Here we report an approach to the imaging of glycans that enables their visualization in the enveloping layer during the early stages of zebrafish embryogenesis. We microinjected embryos with azidosugars at the one-cell stage, allowed the zebrafish to develop, and detected the metabolically labeled glycans with copper-free click chemistry. Mucin-type O-glycans could be imaged as early as 7 hours postfertilization, during the gastrula stage of development. Additionally, we used a nonmetabolic approach to label sialylated glycans with an independent chemistry, enabling the simultaneous imaging of these two distinct classes of glycans. Imaging analysis of glycan trafficking revealed dramatic reorganization of glycans on the second time scale, including rapid migration to the cleavage furrow of mitotic cells. These studies yield insight into the biosynthesis and dynamics of glycans in the enveloping layer during embryogenesis and provide a platform for imaging other biomolecular targets by microinjection of appropriately functionalized biosynthetic precursors.

Baskin, Jeremy M.; Dehnert, Karen W.; Laughlin, Scott T.; Amacher, Sharon L.; Bertozzi, Carolyn R.

2010-01-01

436

Isolation of protoplasts from somatic embryos of carrot  

Microsoft Academic Search

Protoplasts were isolated enzymatically from synchronously induced globular somatic embryos from a carrot suspension culture.\\u000a Among the macerating enzymes tested, Driselase was the most effective for release of protoplasts from embryos. A higher medium\\u000a osmolarity was required for the isolation of protoplasts from embryos than from undifferentiated cells. Protoplasts from embryos\\u000a were smaller than protoplasts from undifferentiated cells. On step

K. Nomura; T. Nitta; T. Fujimura; A. Komamine

1981-01-01

437

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

438

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

Microsoft Academic Search

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

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

1986-01-01

439

[Induced psychiatric and somatic disorders to cannabis].  

PubMed

Cannabis is the most consumed illicit drug. For a number of years it was thought to be not very toxic, although this idea has no scientific backup. The object of much controversy, it is a public health problem for the most vulnerable populations, adolescents, subjects with evolutive psychopathologies and certain highly cognitive situations: driving a car, the professional environment and students. Cannabis breeds, in international classifications of mental disorders, intoxication charts, abuse and dependence, although this last could have been challenged. The complications are basically anxious and psychotic. It is the object of a number of debates associated with schizophrenic disorders, where it seems to be a risk factor where there is a large consumption before the age of fourteen. Like all psychoactive substances, it is an aggravating factor in all evolutive psychopathologies. PMID:18847572

Laqueille, X; Launay, C; Kanit, M

2008-09-04

440

The insect immune protein hemolin is expressed during oogenesis and embryogenesis.  

PubMed

Hemolin is the most abundant bacteria-induced proteins in Hyalophora cecropia hemolymph. Its structural features, both at the protein and gene level, ascribe this molecule to the immunoglobulin gene superfamily (IgSF) with particular homology to neural cell adhesion molecules. An increasing number of evidence suggest a role in immune recognition and in cell adhesion events. Hemolin is also developmentally regulated as suggested by changes in its concentration during larval and pupal ecdysis (Trenczek, T., 1998. Endogenous defense mechanisms of insects. Zoology 101, 298-315; Lanz-Mendoza, H., Faye, I., 1999. Physiological aspects of the immunoglobulin superfamily in invertebrates. Dev. Comp. Immunol. 23, 359-374). In the present study the expression of hemolin was investigated in oogenesis and in early embryogenesis. Our results reveal that hemolin is expressed in follicles and in epidermal and neural tissues of embryos. PMID:10906482

Bettencourt, R; Assefaw-Redda, Y; Faye, I

2000-07-01

441

Optimization of somatic embryogenesis in suspension cultures of horsegram [ Macrotyloma uniflorum (Lam.) Verdc.]—A hardy grain legume  

Microsoft Academic Search

Cell suspension cultures were established from immature cotyledon derived calli from drought tolerant legume horsegram [Macrotyloma uniflorum (Lam.) Verdc.]. Embryogenic callus could be originated from cut slices of the immature cotyledons on MS solid medium [Murashige, T. Skoog, K., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473–497] augmented with 1.0?M zeatin

Shamsudeen Varisai Mohamed; Jih-Min Sung; Toong-Long Jeng; Chang-Sheng Wang

2005-01-01

442

Plant regeneration from cultured immature embryos and inflorescences of Triticum aestivum L. (wheat): Evidence for somatic embryogenesis  

Microsoft Academic Search

Summary Tissue cultures ofTriticum aestivum L. (wheat) initiated from young inflorescences and immature embryos possessed the potential for regeneration of whole plants. Both a friable and a compact type of callus were produced on Murashige and Skoog's medium with 2 mg\\/l 2,4-dichlorophenoxyacetic acid. The friable callus contained meristematic centers in which the peripheral cells ceased dividing, elongated, and could be

Peggy Ozias-Akins; Indra K. Vasil

1982-01-01

443

Induction of somatic embryogenesis and plant regeneration in the tropical timber tree Spanish red cedar [ Cedrela odorata L. (Meliaceae)  

Microsoft Academic Search

Spanish red cedar (Cedrela\\u000a odorata L.) is a tropical timber tree native to the Americas from southern Mexico to northern Argentina. Commercial plantations are\\u000a scarce and, consequently, natural populations are overexploited. Traditional propagation practices for the establishment of\\u000a large-scale plantations have had limited success in this species due to the relative scarcity of seeds, its broad genetic\\u000a diversity and the

Yuri J. Peńa-Ramírez; Israel García-Sheseńa; Ángel Hernández-Espinoza; Alfredo Domínguez-Hernández; Felipe A. Barredo-Pool; José A. González-Rodríguez; Manuel L. Robert

2011-01-01

444

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

445

Somatic embryogenesis and plant regeneration from leaf-derived cell suspension of a mature tree — Thevetia peruviana L  

Microsoft Academic Search

Cell suspension cultures, which retained embryogenic potential for almost 2 years, were established from young, expanding, juvenile leaves of a mature Thevetia peruviana L. tree. Calli were obtained by culturing young leaf discs on MS medium supplemented with 2 mg\\/L 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 0.1 mg\\/L kinetin. Suspension cultures were initiated by transfer of calli to liquid medium

Abha Sharma; Anjani Kumar

1994-01-01

446

The effect of several factors on somatic embryogenesis and plant regeneration in protoplast cultures of Gentiana kurroo (Royle)  

Microsoft Academic Search

Protoplasts were isolated from cell suspensions derived from cotyledon and hypocotyl Gentiana kurroo (Royle). Cell walls were digested with an enzyme cocktail containing cellulase, macerozyme, driselase, hemicellulase and\\u000a pectolyase in CPW solution. Protoplast viability ranged from 88 to 96%. Three techniques of culture and six media were evaluated\\u000a in terms of their efficiency in producing viable cultures and regenerating whole

Agnieszka Fiuk; Jan J. Rybczy?ski

2007-01-01

447

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

448

Mobile DNA transposition in somatic cells.  

PubMed

It had been long assumed that almost all insertions of mobile DNA elements occurred during germ-cell development rather than in somatic-cell development, but solid evidence for transposition in somatic cells is now accumulating. To add to this evidence, a recent paper in Mobile DNA reports the somatic transposition of a site-specific retrotransposon, R2, into its insertion site in 28S ribosomal DNA in Drosophila embryos. PMID:21958341

Kazazian, Haig H

2011-09-29

449

Establishment and plant regeneration of somatic embryogenic cell suspension cultures of the Zingiber officinale Rosc  

Microsoft Academic Search

Somatic embryogenic cell suspension cultures of four ginger cultivars were established. Somatic embryogenic calli were induced from ginger shoot tips on MS agar medium supplemented with 1.0mgl?1 2,4-D and 0.2mgl?1 Kn, which contained only half concentration of NH4NO3. Rapid-growing and well-dispersed suspension cultures were established by subculturing this kind of callus in the same liquid MSN medium. The suspension cultures

Yinghua Guo; Zhenxian Zhang

2005-01-01

450

Reprogramming of murine and human somatic cells using a single polycistronic vector  

Microsoft Academic Search

Directed reprogramming of somatic cells by defined factors provides a novel method for the generation of patient-specific stem cells with the potential to bypass both the practical and ethical concerns associated with somatic cell nuclear transfer (SCNT) and human embryonic stem (hES) cells. Although the generation of induced pluripotent stem (iPS) cells has proven a robust technology in mouse and

Bryce W. Carey; Styliani Markoulaki; Jacob Hanna; Kris Saha; Qing Gao; Maisam Mitalipova; Rudolf Jaenisch

2009-01-01

451

Accumulation of Group 3 Late Embryogenesis Abundant Proteins in Zea mays Embryos 1  

PubMed Central

Several different types of proteins that are modulated by abscisic acid (ABA) accumulate in developing embryos of maize (Zea mays L.). Some of these proteins are specific to the developing seed, such as the storage globulin, GLB1, whereas others are involved in general responses to water deficit. Here we describe a maize protein family of this second type, a Group 3 late embryogenesis abundant (MLG3). Like other proteins of this class, MLG3 polypeptides are ABA-responsive. They are found in maturing seeds and in dehydrating plant tissues. Antigenically related proteins are found in other cereals. To distinguish the regulation of developmentally programmed ABA responses from those that are environmentally induced, we compared the ontological pattern and accumulation requirements of MLG3 polypeptides with those we previously described for GLB1. GLB1 accumulation begins early in the maturation phase and specifically requires high levels of ABA and the participation of the Viviparous-1 (Vp1) gene product. Vp1 is required for other ABA-modulated events in maize seed development as well. In experiments using vp1 mutants and mutants deficient in ABA synthesis (vp5 mutation), we show that MLG3 accumulation also is dependent upon ABA, but it shows striking differences from GLB1. MLG3 accumulates much later in embryogenesis, coincident with the onset of dehydration. In contrast to GLB1, MLG3 proteins can be induced by de novo ABA synthesis in response to culturing in high osmoticum. Unlike GLB1, MLG3 has no specific requirement for the Vp1 gene product. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8

Thomann, Estela B.; Sollinger, John; White, Constance; Rivin, Carol J.

1992-01-01

452

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

453

ENABLING THE SOMATIZING PATIENT TO EXIT THE SOMATIC CLOSET: A HIGH-RISK MODEL  

Microsoft Academic Search

Problems in establishing a therapeutic alliance make somatizing patients poor candidates for psychotherapy. A logical analysis is presented of the conspiracy of silence between the somatizing patient, the medical doctor, and the health insurance industry regarding the psychosocial factors contributing to somatization. Alternatives are sought to repeated biomedical tests and therapies that are clinically unproductive and iatrogenic. Two psychophysiological pathways

Ian Wickramasekera

1989-01-01

454

A Combined Epigenetic and Non-Genetic Approach for Reprogramming Human Somatic Cells  

PubMed Central

Reprogramming of somatic cells to different extents has been reported using different methods. However, this is normally accompanied by the use of exogenous materials, and the overall reprogramming efficiency has been low. Chemicals and small molecules have been used to improve the reprogramming process during somatic cell nuclear transfer (SCNT) and induced pluripotent stem (iPS) cell generation. We report here the first application of a combined epigenetic and non-genetic approach for reprogramming somatic cells, i.e., DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors, and human embryonic stem cell (hESC) extracts. When somatic cells were pretreated with these inhibitors before exposure to hESC (MEL1) extracts, morphological analysis revealed a higher rate of hESC-like colony formation than without pretreatment. Quantitative PCR (qPCR) demonstrated that pluripotency genes were upregulated when compared to those of somatic cells or treated with hESC extracts alone. Overall changes in methylation and acetylation levels of pretreated somatic cells suggests that epigenetic states of the cells have an effect on reprogramming efficiency induced by hESC extracts. KnockOutserum replacement (KOSR™) medium (KO-SR) played a positive role in inducing expression of the pluripotency genes. hESC extracts could be an alternative approach to reprogram somatic cells without introducing exogenous materials. The epigenetic pre-treatment of somatic cells could be used to improve the efficiency of reprogramming process. Under differentiation conditions, the reprogrammed cells exhibited differentiation ability into neurons suggesting that, although fully reprogramming was not achieved, the cells could be transdifferentiated after reprogramming.

Han, Jinnuo; Sachdev, Perminder S.; Sidhu, Kuldip S.

2010-01-01

455

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 reshapi