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1

Induction of somatic embryogenesis in Azadirachta indica  

Microsoft Academic Search

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

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

1997-01-01

2

Induction of somatic embryogenesis and DNA fingerprinting of Jojoba  

Microsoft Academic Search

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

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

3

Induction of plant somatic embryogenesis in liquid medium  

Microsoft Academic Search

The large scale propagation of plants via somatic embryogenesis, has so far been difficult to achieve. In this thesis research is described leading to embryogenic cell lines that can be maintained for a long period, without loss of genetic stability. It is also described how embryogenic potential of cell lines can be influenced by the addition of specific arabinogalactan-proteins.We consider

M. Kreuger

1996-01-01

4

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

Microsoft Academic Search

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

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

2007-01-01

5

Somatic embryogenesis induction in leaves and petioles of a mature wild olive  

Microsoft Academic Search

We describe a protocol for somatic embryogenesis (SE) induction from an adult wild olive tree (Olea\\u000a europaea ssp. europaea var. sylvestris. The protocol used confirms for the first time that there is no need to use juvenile or rejuvenated material for SE induction.\\u000a For SE induction, petiole and leaf (proximal, intermediary and distal zones) explants were grown on Murashige and

Ana Margarida Capelo; Sónia Silva; Gina Brito; Conceiçăo Santos

2010-01-01

6

Induction and establishment of somatic embryogenesis in elite Indian cotton cultivar (Gossypium hirsutumL. cv Khandwa-2)  

PubMed Central

Embryogenesis in cotton is a difficult task due its genome dependency. We used 3 cotton cultivars (Khandwa-2, G. Cot. 10, and BC-68–2) and Coker-312 as control for regeneration. Efficient somatic embryogenesis was induced in agronomically important Indian cotton cultivars, Khandwa-2 and G. Cot. 10. For callusing in all the cultivars, different media combinations were tried. Embryogenesis was initiated on a hormone-free MS medium (MSB). For embryo maturation and recovery excess of L-glutamine and l-asparagine were used. Khandwa-2 somatic embryos were successfully regenerated into plants. However, no plantlet was obtained in case of G. Cot. 10. Callus induction was also observed in BC-68–2 but there was no embryogenesis observed. The study indicated that the medium and genotype significantly effects embryogenesis. An efficient protocol is described here for regenerating plants via somatic embryogenesis in an elite Indian cotton cultivar Khandwa-2.

Kumar, Manoj; Singh, Harpal; Shukla, Anoop Kumar; Verma, Praveen Chandra; Singh, Pradhyumna Kumar

2013-01-01

7

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

8

Induction of somatic embryogenesis and embryo development in Rumex acetosella L  

Microsoft Academic Search

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

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

1987-01-01

9

Expression of PiABP19, Picdc2 and PiSERK3 during induction of somatic embryogenesis in leaflets of Prunus incisa (Thunb.).  

PubMed

Somatic embryogenesis is a useful tool of plant breeding. In this context, a procedure for inducing somatic embryogenesis in Prunus incisa leaf explants had been previously developed. The original in vitro protocol relies on picloram treatments and exposure to darkness as inductive conditions, the best frequency of embryogenesis being obtained on the second leaf (F(2)) exposed to 4 ?M picloram during 30 days. The morphological and biochemical changes observed during somatic embryogenesis occur in response to alterations in gene expression regulation patterns. A molecular study was conducted in order to provide deeper insight into the fundamental biological factors involved in the induction of this process using a gene candidate strategy and semi-quantitative reverse transcription polymerase chain reaction analysis. So far, no sequence data related to somatic embryogenesis has been available in cherry. In the present study, we cloned and sequenced cDNA fragments of putative genes encoding auxin-binding protein, cell cycle regulator and somatic embryogenesis receptor kinase. Time-course differential transcript accumulations were observed for all investigated genes in leaves or derived callus tissues during the observation period (first month of culture). Their possible involvement in the sequential steps of the embryogenic pathway (dedifferentiation, cell proliferation, differentiation through somatic embryogenesis) is presented and discussed. PMID:23086274

Ben Mahmoud, Kaouther; Delporte, Fabienne; Muhovski, Yordan; Elloumi, Nadhra; Jemmali, Ahmed; Druart, Philippe

2013-02-01

10

A new approach to direct somatic embryogenesis in Medicago  

Microsoft Academic Search

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

P. Denchev; M. Velcheva; A. Atanassov

1991-01-01

11

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

PubMed Central

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

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

2013-01-01

12

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

13

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

14

Vegetative propagation of Quercus suber L. by somatic embryogenesis  

Microsoft Academic Search

The regeneration of somatic seedlings from selected 100-year-old cork oak trees is reported. The induction of somatic embryogenesis from leaves of epicormic shoots was significantly affected by genotype, harvesting time and their interaction. Leaves from all five selected trees produced somatic embryos when the segments of branches used as sources of epicormic shoots were collected in May. Genotype, but not

I. Hernández; C. Celestino; J. Alegre; M. Toribio

2003-01-01

15

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

PubMed

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

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

1996-02-01

16

Vegetative propagation of Quercus suber L. by somatic embryogenesis. I. Factors affecting the induction in leaves from mature cork oak trees.  

PubMed

Somatic embryogenesis was induced in expanding leaves from epicormic shoots forced to sprout from segments of branches collected from several hundred-year-old cork oak trees. Following a basic protocol previously defined for leaves taken from seedlings of this species, several factors were studied to improve the response. The induction frequency was significantly higher when the length of exposure to growth regulators was increased from 7 to 30 days. The combined application of NAA and BAP was essential for induction. Although both regulators had a very significant influence, their interaction was not significant, suggesting independent roles. Leaf size had a crucial effect, because beyond a certain threshold, embryogenesis could not be obtained. Embryogenic lines were maintained via repetitive embryogenesis on hormone-free medium for more than 2 years. PMID:12789519

Hernández, I; Celestino, C; Toribio, M

2003-04-01

17

Walnut somatic embryogenesis: physiological and histological aspects  

E-print Network

Walnut somatic embryogenesis: physiological and histological aspects D. Cornu Amdlioration des and cultivated as described previously (Cornu, 1988). For histological studies, suitable tissue samples were

Paris-Sud XI, Université de

18

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

19

Secondary somatic embryogenesis and applications in plant breeding  

Microsoft Academic Search

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

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

1995-01-01

20

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

21

Vegetative propagation of Quercus suber L. by somatic embryogenesis  

Microsoft Academic Search

Somatic embryogenesis was induced in expanding leaves from epicormic shoots forced to sprout from segments of branches collected from several hundred-year-old cork oak trees. Following a basic protocol previously defined for leaves taken from seedlings of this species, several factors were studied to improve the response. The induction frequency was significantly higher when the length of exposure to growth regulators

I. Hernández; C. Celestino; M. Toribio

2003-01-01

22

A novel type of somatic embryogenesis in Coffea arabica  

Microsoft Academic Search

A novel type of somatic embryogenesis characterized by an efficient and highly synchronized embryo formation was observed in embryogenic callus of Coffea arabica initiated on Murashige and Skoog medium containing kinetin (4 mg\\/l) and 2,4-D (1 mg\\/l). It occurs in suspension and goes along with the suppression of “High Frequency Somatic Embryo Induction” (HFSE). This is achieved by favoring during

Beat Neuenschwander; Thomas W. Baumann

1992-01-01

23

Morphohistological analysis and histochemistry of Feijoa sellowiana somatic embryogenesis  

Microsoft Academic Search

Summary. Morphohistological analysis and histochemical studies were carried out during the induction and development of Feijoa sellowiana somatic embryos. Zygotic embryos were cultured on LPm medium containing 2,4-dichlorophenoxyacetic acid (20?µM) and glutamine (8?mM). Somatic embryogenesis could be induced from embryogenic cells that originated in meristematic centers or from clusters of cells. The presence of few starch grains and abundant protein

G. C. Cangahuala-Inocente; N. Steiner; M. Santos; M. P. Guerra

2004-01-01

24

Somatic embryogenesis in wild cherry (Prunus avium)  

Microsoft Academic Search

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

Elisabeth Garin; Emmanuel Grenier; Ghislaine Grenier-De March

1997-01-01

25

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

PubMed Central

Background and Aims The thin cell layer (TCL) technique is based on the use of very small explants and has allowed enhanced in vitro morphogenesis in several plant species. The present study evaluated the TCL technique as a procedure for somatic embryo production and plantlet regeneration of peach palm. Methods TCL explants from different positions in the shoot apex and leaf sheath of peach palm were cultivated in MS culture medium supplemented with 0–600 µm Picloram in the presence of activated charcoal. The production of primary calli and embryogenic calli was evaluated in these different conditions. Histological and amplified fragment length polymorphism (AFLP) analyses were conducted to study in vitro morphogenetic responses and genetic stability, respectively, of the regenerated plantlets. Key Results Abundant primary callus induction was observed from TCLs of the shoot meristem in culture media supplemented with 150–600 µm Picloram (83–97 %, respectively). The production of embryogenic calli depends on Picloram concentration and explant position. The best response observed was 43 % embryogenic callus production from shoot meristem TCL on 300 µm Picloram. In maturation conditions, 34 ± 4 somatic embryos per embryogenic callus were obtained, and 45·0 ± 3·4 % of these fully developed somatic embryos were converted, resulting in plantlets ready for acclimatization, of which 80 % survived. Histological studies revealed that the first cellular division events occurred in cells adjacent to vascular tissue, resulting in primary calli, whose growth was ensured by a meristematic zone. A multicellular origin of the resulting somatic embryos arising from the meristematic zone is suggested. During maturation, histological analyses revealed bipolarization of the somatic embryos, as well as the development of new somatic embryos. AFLP analyses revealed that 92 % of the regenerated plantlets were true to type. The use of TCL explants considerably improves the number of calli and somatic embryos produced in comparison with previously described protocols for in vitro regeneration of peach palm. Conclusions The present study suggests that the TCL somatic embryogenesis protocol developed is feasible, although it still requires further optimization for in vitro multiplication of peach palm, especially the use of similar explants obtained from adult palm trees. PMID:17670751

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

2007-01-01

26

Somatic embryogenesis in Hedychium bousigonianum  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

27

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

28

A new approach to direct somatic embryogenesis in Medicago.  

PubMed

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

Denchev, P; Velcheva, M; Atanassov, A

1991-09-01

29

Somatic embryogenesis in plantain banana  

Microsoft Academic Search

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

A. Grapin; J. Schwendiman; C. Teisson

1996-01-01

30

Somatic Embryogenesis in Mature Quercus Robur Trees  

Microsoft Academic Search

Somatic embryo induction and plant regeneration have been obtained in tissues from mature Quercus robur L. trees. Epicormic shoots were forced to flush in branch segments collected from the crown of trees growing in selected stands on different collection dates. Expanding leaves from five genotypes, cultured following a multistage treatment procedure, produced somatic embryos at frequencies ranging from 0.3 to

M. Toribio; C. Fernández; C. Celestino; M. T. Martínez; A. M. Vieitez

2004-01-01

31

Studies for Somatic Embryogenesis in Sweet Potato  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

32

Studies on Somatic Embryogenesis in Sweetpotato  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

33

Inheritance of somatic embryogenesis and organ regeneration from immature embryo cultures of winter wheat  

Microsoft Academic Search

Diallel analyses of F1 and reciprocal crosses among five winter wheat lines show that additive, non-additive, and cytoplasmic genetic effects were significant in the genetic control of somatic embryogenesis, shoot, and root induction frequencies as well as in numbers of somatic embryos, shoots, and roots. However, additive genetic effect appears to be most important since, in most cases a larger

G. Ou; W. C. Wang; H. T. Nguyen

1989-01-01

34

Spaceflight reduces somatic embryogenesis in orchardgrass (Poaceae)  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

35

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

36

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

Microsoft Academic Search

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

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

1987-01-01

37

Relationship between ploidy variation of citrus calli and competence for somatic embryogenesis.  

PubMed

This study focuses on the relationship between the genetic variation of calli and the competence for somatic embryogenesis in citrus. The DNA content of 35 citrus calli of different genotypes was measured three times by flow cytometry during a period of four years. The results showed that 71.4 % of the genotypes had a progressive increase of varied cells, while those of Page tangelo, Shamouti sweet orange, Russ navel orange and Cleopatra decreased; significant difference in the variation degree (percentages) existed among genotypes. Studies carried out on the induction of somatic embryogenesis revealed that 9 out of the 35 genotypes had still kept the competence of somatic embryogenesis, and the rest 26 had lost the competence. Correlation analysis indicated that there was no significant relationship between the variation degree and the embryogenesis competence r = -0.10 (P < 0.01), neither for the relationship between the subculture duration and the regeneration capacity. PMID:16875323

Zhang, Jun-E; Guo, Wen-Wu; Deng, Xiu-Xin

2006-07-01

38

Papaver somniferum regeneration by somatic embryogenesis and shoot organogenesis  

Microsoft Academic Search

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

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

1997-01-01

39

[Improvement of somatic embryogenesis process in sugarcane Venezuelan cultivars].  

PubMed

Efficient embryogenic callus formation (70%) in many sugarcane cultivars, has been established using young leaf explants cultivated on modified Murashige and Skoog medium containing 13 microM 2,4-dichlorophenoxiacetic acid (2,4-D). However, Venezuelan sugarcane cultivars V78-1 and V75-6 produced only 30% of embryogenic callus when were cultured in these conditions. In order to improve somatic embryogenesis in these Venezuelan cultivars, embryogenic calli were induced using different media: C3 (13 microM 2,4-D); C7 (31.5 microM 2,4-D); Cd (30 microM Dicamba) and C5BA (22.5 microM 2,4-D, 22.2 microM N6-Benzyladenine). After 45 days of induction, the highest embryogenic callus production (90%), was observed in both cultivars, when they were cultured on Cd medium. Moreover, plant development from somatic embryos originated in this callus, was evident four days after incubation on regeneration medium (without hormones), while the somatic embryos originated from calli growing in C3, C7 and C5BA media, gave rise to plants eight days after incubation on regeneration medium. PMID:12945490

Marcano, Ana Karina; Molina Guevara, Pedro; Oropeza, Maira; de García, Eva

2002-01-01

40

Callose deposition is required for somatic embryogenesis in plasmolyzed Eleutherococcus senticosus zygotic embryos.  

PubMed

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. PMID:23203053

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

2012-01-01

41

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

Microsoft Academic Search

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

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

2010-01-01

42

Genotype-specific normalization of soybean somatic embryogenesis through the use of an ethylene inhibitor  

Microsoft Academic Search

The effect of ethylene on somatic embryogenesis from cotyledons of soybean (Glycine max) cultivars `Bragg', `IAS-5', and `RS-7' was studied through the application of silver nitrate or aminoethoxyvinylglycine.\\u000a The addition of these chemicals to the induction medium had no effect on embryo induction, in spite of aminoethoxyvinylglycine\\u000a having decreased ethylene production and silver nitrate enhancing it. However, subsequent histodif-ferentiation and

K. G. B. Santos; E. Mundstock; M. H. Bodanese-Zanettini

1997-01-01

43

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

44

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

45

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

Microsoft Academic Search

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

Li Shan; Shen Zhenghu; Qin Zhi; Wang Yafu

2001-01-01

46

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

Microsoft Academic Search

Efficient plant regeneration via somatic embryogenesis has been developed in chickpea cultivar C235. Leaf explants, on MS medium supplemented with 1.25 mg\\/l 2,4-D and 0.25 mg\\/l kinetin, yielded somatic embryos with high efficiency during dark incubation. MS medium supplemented with B5 vitamins, 0.125 mg\\/l IBA and 2 mg\\/l BAP was found suitable for embryo maturation. The well formed embryos germinated

V. Dinesh Kumar; P. B. Kirti; J. K. S. Sachan; V. L. Chopra

1994-01-01

47

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

48

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

Microsoft Academic Search

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

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

1999-01-01

49

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

Microsoft Academic Search

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

Baochun Li; David J. Wolyn

1995-01-01

50

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

51

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

52

Somatic embryogenesis from Sorghum bicolor leaves  

Microsoft Academic Search

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

Wolfgang Wernicke; Richard Brettell

1980-01-01

53

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

54

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

55

Alternative oxidase involvement in Daucus carota somatic embryogenesis.  

PubMed

Plant alternative oxidase (AOX) is a mitochondrial inner membrane enzyme involved in alternative respiration. The critical importance of the enzyme during acclimation upon stress of plant cells is not fully understood and is still an issue of intensive research and discussion. Recently, a role of AOX was suggested for the ability of plant cells to change easily its fate upon stress. In order to get new insights about AOX involvement in cell reprogramming, quantitative real-time polymerase chain reaction (PCR) and inhibitor studies were performed during cell redifferentiation and developmental stages of Daucus carota L. somatic embryogenesis. Transcript level analysis shows that D. carota AOX genes (DcAOX1a and DcAOX2a) are differentially expressed during somatic embryogenesis. DcAOX1a shows lower expression levels, being mainly down-regulated, whereas DcAOX2a presented a large up-regulation during initiation of the realization phase of somatic embryogenesis. However, when globular embryos start to develop, both genes are down-regulated, being this state transient for DcAOX2a. In addition, parallel studies were performed using salicylhydroxamic acid (SHAM) in order to inhibit AOX activity during the realization phase of somatic embryogenesis. Embryogenic cells growing in the presence of the inhibitor were unable to develop embryogenic structures and its growth rate was diminished. This effect was reversible and concentration dependent. The results obtained contribute to the hypothesis that AOX activity supports metabolic reorganization as an essential part of cell reprogramming and, thus, enables restructuring and de novo cell differentiation. PMID:19863756

Frederico, António Miguel; Campos, Maria Doroteia; Cardoso, Hélia Guerra; Imani, Jafargholi; Arnholdt-Schmitt, Birgit

2009-12-01

56

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

PubMed

Camellia nitidissima Chi (Theaceae) is a world-famous economic and ornamental plant with golden-yellow flowers. It has been classified as one of the rarest and most endangered plants in China. Our objective was to induce somatic embryogenesis, shoot organogenesis and plant regeneration for C. nitidissima. Three types of callus (whitish, reddish and yellowish) were induced from immature cotyledons on improved woody plant medium (WPM) with different plant growth regulators (PGRs). Among the callus, whitish callus was induced by 4.5 ?M 2,4-dichlorophenoxyacetic acid (2,4-D) and reddish and yellowish callus were induced by strongly active cytokinins, thidiazuron (TDZ) or 6-benzylaminopurine (BAP), singly or combined with weakly active auxin, ?-naphthaleneacetic acid (NAA). The embryogenic callus could differentiate into somatic embryos, nodular embryogenic structures (large embryo-like structures) or adventitious shoots depending on the PGR used in WPM. BAP was best for adventitious buds and zeatin was best for somatic embryogenesis while kinetin (Kt) was best for the formation of nodular embryogenic structures. The three regeneration pathways often occurred in the same embryogenic callus clumps. Most shoots (80.0%) developed roots in WPM supplemented with 24.6 ?M IBA and 0.3 ?M NAA while 47.5% of somatic embryos could germinate directly and develop into plantlets on induction medium supplemented with 0.9 ?M BAP and 0.1 ?M NAA. The nodular embryogenic structures could be sub-cultured and cyclically developed in one of two differentiation pathways: shoot organogenesis or somatic embryogenesis. Plantlets derived from shoot buds rooted and somatic embryos germinated when transplanted into soil in a greenhouse; 66.7% of plantlets from shoot culture and 78.6% of plantlets from somatic embryos survived after 8 weeks' acclimatization. PMID:23790533

Lü, Jinfeng; Chen, Rong; Zhang, Muhan; da Silva, Jaime A Teixeira; Ma, Guohua

2013-09-01

57

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

58

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

59

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

Microsoft Academic Search

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

Haoru Tang; Zhenglong Ren; Gabi Krczal

2000-01-01

60

Development of a cyclic somatic embryogenesis regeneration system for leek (Allium ampeloprasum L.) using zygotic embryos.  

PubMed

In leek (Allium ampeloprasum L.) a cyclic system of somatic embryogenesis was developed. Somatic embryos used for cyclic embryogenesis were able to develop the same type of embryogenic callus as zygotic embryos in the primary cycle. For the first time a comparison of the efficiencies of both expiants was made. Ten families were investigated for somatic embryogenesis. There was a genetic relationship with respect to somatic embryo production between the reciprocal crosses. From each family one genotype was selected for investigating cyclic somatic embryogenesis. Different levels of somatic embryo production were found between the expiants of zygotic and somatic embryos. The two best genotypes, 92.001-03 and 92.002-33 produced twice as many somatic embryos as the overall average. On average, 56% of the somatic embryos finally developed into greenhouse plantlets. PMID:24190300

Schavemaker, C M; Jacobsen, E

1995-01-01

61

Propagation of Coriandrum sativum L. through somatic embryogenesis.  

PubMed

A highly embryogenic callus was obtained from hypocotyl segments of Coriandrum sativum L. when cultured in the medium consisting of MS + H vitamins (MSH). Induction of somatic embryos required 2,4-dichlorophenoxyacetic acid or napthalene acetic acid. Germination of fully developed embryos was accomplished by subculture on half strength MSH medium containing benzylamino purine 0.05 mg/L. Plantlets developed from somatic embryos were transferred to soil and were successfully flowered. PMID:11491588

Stephan, R; Jayabalan, N

2001-04-01

62

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

Microsoft Academic Search

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

R. Ramakrishnan Nair; S. Dutta Gupta

2006-01-01

63

Vegetative propagation of Quercus suber L. by somatic embryogenesis. II. Plant regeneration from selected cork oak trees.  

PubMed

The regeneration of somatic seedlings from selected 100-year-old cork oak trees is reported. The induction of somatic embryogenesis from leaves of epicormic shoots was significantly affected by genotype, harvesting time and their interaction. Leaves from all five selected trees produced somatic embryos when the segments of branches used as sources of epicormic shoots were collected in May. Genotype, but not the level of photosynthetically active radiation, affected the proliferation of the embryogenic lines and the number of detachable embryos that could be obtained from them. Genotype also affected several steps leading to conversion of somatic embryos, from germination to complete acclimatisation of somatic seedlings. Almost 40% of the somatic embryos from all lines germinated, showing coordinated root and shoot growth. Although the mean percentage of recovery for the whole process was low, plants could be regenerated from four of the five trees tested. PMID:12789520

Hernández, I; Celestino, C; Alegre, J; Toribio, M

2003-04-01

64

Somatic embryogenesis in sisal ( Agave sisalana Perr. ex. Engelm).  

PubMed

A protocol has been developed for somatic embryogenesis and plant regeneration of sisal (Agave sisalana Perr. ex. Engelm). Embryogenic callus cultures were initiated from young shoots raised in vitro from the stem portion of the bulbil on medium supplemented with 1-2 mg l(-1) kinetin (KN) and 0.2-0.5 mg l(-1) alpha-naphthaleneacetic acid plus KN or 1-1.5 mg l(-1 )benzylaminopurine (BAP) or 0.25-0.5 mg l(-1 )2,4-dichlorophenoxyacetic acid plus BAP or 0.5-1.0 mg l(-1) KN. Embryos at various developmental stages (globular-, heart- or torpedo-shaped) produced mature and germinating embryos on being transferred to a new medium containing 0-0.25 mg l(-1 )KN. After 28 days, a maximum of 76% germinated embryos was obtained on a medium supplemented with 0.1 mg l(-1) KN. The capacity for embryogenesis remained constant in the callus upon subculturing on the same medium for more than 48 months. Histological observations showed a distinct multicellular origin for most of the somatic embryos as they developed from epidermal, sub-epidermal and inside callus cells, while a few of them originated from a superficial callus cell. Plantlets regenerated from embryos were transferred to the field where their survival rate was 100%. PMID:12920563

Nikam, T D; Bansude, G M; Aneesh Kumar, K C

2003-10-01

65

Proteome analysis of early somatic embryogenesis in Picea glauca.  

PubMed

Forestry is a valuable natural resource for many countries. Rapid production of large quantities of genetically improved and uniform seedlings for restocking harvested lands is a key component of sustainable forest management programs. Clonal propagation through somatic embryogenesis has the potential to meet this need in conifers and can offer the added benefit of ensuring consistent seedling quality. Although in commercial use, mass production of conifers through somatic embryogenesis is relatively new and there are numerous biological unknowns regarding this complex developmental pathway. To aid in unravelling the embryo developmental process, two-dimensional electrophoresis was employed to quantitatively assess the expression levels of proteins across four stages of somatic embryo maturation in white spruce (0, 7, 21 and 35 days post abscisic acid treatment). Forty-eight differentially expressed proteins have been identified, which display a significant change in abundance as early as day 7 of embryo development. These proteins are involved in a variety of cellular processes, many of which have not previously been associated with embryo development. The identification of these proteins was greatly assisted by the availability of a substantial expressed sequence tag (EST) resource developed for white, sitka and interior spruce. The combined use of these spruce ESTs in conjunction with GenBank accessions for other plants improved the rate of protein identification from 38% to 62% when compared with GenBank alone using automated, high-throughput techniques. This underscores the utility of EST resources in a proteomic study of any species for which a genome sequence is unavailable. PMID:15627954

Lippert, Dustin; Zhuang, Jun; Ralph, Steven; Ellis, Dave E; Gilbert, Margarita; Olafson, Robert; Ritland, Kermit; Ellis, Brian; Douglas, Carl J; Bohlmann, Jörg

2005-02-01

66

Cyclic secondary somatic embryogenesis and efficient plant regeneration in camphor tree ( Cinnamomum camphora L.)  

Microsoft Academic Search

An efficient protocol for secondary somatic embryogenesis in camphor tree is reported. Secondary somatic embryos (SSEs), initially\\u000a obtained from the primary embryos of a nascent embryogenic culture in 2002, were proliferated and maintained for more than\\u000a 4 yr via cyclic secondary somatic embryogenesis. Throughout this period, the embryo populations retained a high level of competence\\u000a for plant regeneration. SSEs were produced

Xueping Shi; Xigang Dai; Guofeng Liu; Junwei Zhang; Guogui Ning; Manzhu Bao

2010-01-01

67

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

68

Improvements of cyclic somatic embryogenesis of cassava (Manihot esculenta Crantz).  

PubMed

In cassava a cyclic system of somatic embryogenesis was developed. Primary (torpedo shaped or germinated) embryos, originating from leaf lobes, could only be obtained after culture on solid medium. Cyclic embryos, originating from embryos, could be obtained in both liquid and on solid medium. The production of embryos in liquid medium was distinctly higher, faster and more synchronized than on solid medium. Lower densities and fragmentation of starting embryos improved the production significantly. The highest production found was 32.1 embryos per initial embryo. In all treatments the explants initiated multiple embryos. The production of single embryos was achieved by pressing starting embryos through a fine meshed sieve, indicating that embryos can be produced from a piece of tissue with a restricted number of cells. The shoot conversion rate of embryos from liquid medium was comparable with that of embryos from solid medium. PMID:24197025

Raemakers, C J; Schavemaker, C M; Jacobsen, E; Visser, R G

1993-02-01

69

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

70

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

PubMed

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

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

2014-09-01

71

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

PubMed Central

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

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

2013-01-01

72

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

PubMed

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

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

2013-06-01

73

Somatic embryogenesis in cultured immature zygotic embryos and leaf protoplasts of Arabidopsis thaliana ecotypes.  

PubMed

Immature zygotic embryos of six ecotypes (Nd-0, Ler, C24, Col-0, Nossen, Ws-2) of Arabidopsis thaliana (L.) Heynh. were cultured in vitro. The same ecotypes, except Nossen, were used for studies on leaf protoplast culture. Experimental conditions for the induction of somatic embryos were established in both culture systems. In the case of immature zygotic embryos, the parameters investigated were the influence of developmental stage of the explant, the ecotypes used, and various concentrations and combinations of growth regulatory substances (phytohormones). In the ecotype Ler, structures were discovered which were very similar to those found in the early stages of zygotic embryo-genesis: globular structures at the end of a suspensor-like single file of cells were frequently observed. In the case of leaf protoplasts, high efficiencies of colony formation and plant regeneration occurred in Ws-2 and C24. A novel type of cell division pattern was found in Col-0 and C24, again highly reminiscent of the early division patterns in zygotic embryos. Similarities and differences between zygotic and somatic embryogenesis are discussed. PMID:9232908

Luo, Y; Koop, H U

1997-01-01

74

Isolation of two somatic embryogenesis-related genes from orchardgrass ( Dactylis glomerata)  

Microsoft Academic Search

Orchardgrass (Dactylis glomerata L.) leaf segments have a high capacity for direct embryogenesis from mesophyll cells and indirect embryogenesis through callus. Total RNA extracted from leaf cultures of embryogenic and nonembryogenic genotypes were used to generate two differentially expressed cDNA fragments. An embryogenic leaf culture cDNA library was screened with these fragments and two somatic embryogenesis-related genes designated DGE1 and

Krassimira S Alexandrova; B. V Conger

2002-01-01

75

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

Microsoft Academic Search

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

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

1989-01-01

76

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

77

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

78

Somatic embryogenesis and plant regeneration from leaf tissue of jojoba  

Microsoft Academic Search

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

L. Hamama; M. Baaziz; R. Letouzé

2001-01-01

79

Screening of diploid Medicago sativa germplasm for somatic embryogenesis.  

PubMed

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

Meijer, E G; Brown, D C

1985-10-01

80

The somatic embryogenesis and plant regeneration from immature embryo of sweet corn inbred line  

Microsoft Academic Search

Synthetic seed consisting of somatic embryos enclosed in protective coating are a suitable tool for clonal mass propagation of elite plant varieties. The in vitro study was aimed to evaluate the optimizing medium for sweet corn somatic embryogenesis, synthetic seed production which leads to increasing germination and seed viability percentage. The in vitro study was aimed to evaluate the optimizing

Pitipong Thobunluepop

2009-01-01

81

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

Microsoft Academic Search

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

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

2005-01-01

82

RESEARCH ARTICLE Somatic embryogenesis, rhizogenesis, and morphinan alkaloids production in two species of opium poppy  

E-print Network

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

My Abdelmajid Kassem; Annie Jacquin

83

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

PubMed

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

Kassem, My Abdelmajid; Jacquin, Annie

2001-01-01

84

Somatic embryogenesis of holm oak ( Quercus ilex L.): ethylene production and polyamine content  

Microsoft Academic Search

The production of ethylene and the endogenous content of polyamines (PAs) have been recorded during the early development,\\u000a maturation and germination of holm oak (Quercus ilex L.) somatic embryos. Ethylene production was high in embryogenic callus, immature somatic embryos and in explants showing\\u000a secondary embryogenesis, while it was lower in mature and germinating somatic embryos. A higher ethylene production was

Pedro V. MauriJose; Jose A. Manzanera

2011-01-01

85

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

Microsoft Academic Search

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

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

1994-01-01

86

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

PubMed Central

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

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

2015-01-01

87

Involvement of polyamine biosynthesis in somatic embryogenesis of Valencia sweet orange (Citrus sinensis) induced by glycerol.  

PubMed

Culture of Citrus sinensis embryogenic callus on the embryo-inducing medium (EIM) containing glycerol gave rise to a large number of embryos, whereas very few embryos were observed on the callus growth medium (CGM). In the current paper, attempts were made to investigate whether polyamine biosynthesis was involved in glycerol-mediated somatic embryogenesis. Quantification of free polyamines by high-performance liquid chromatography showed that the cultures on EIM had less putrescine than those on CGM. However, increase in spermidine and spermine was detected in cultures on EIM during the first 20d of culture, coincident with abundant somatic embryogenesis. The globular embryos contained more polyamines than embryos at other stages. Semi-quantitative reverse transcriptase-polymerase chain reaction assay showed that expression levels of all of the five key genes involved in polyamine biosynthesis, with the exception of S-adenosylmethionine decarboxylase, were induced in cultures on EIM, and that their transcriptional levels were increased with maturation of the embryos. Addition of alpha-difluoromethylornithine, a polyamine biosynthesis inhibitor, to EIM resulted in remarkable inhibition of somatic embryogenesis, concurrent with notable reduction of endogenous putrescine and spermidine, particularly at higher concentrations. Exogenous application of 1mM putrescine to EIM together with 5mM alpha-difluoromethylornithine led to dramatic enhancement of endogenous polyamines, which successfully restored somatic embryogenesis. All of these, collectively, demonstrated that free polyamines, at least spermidine and spermine herein, were involved in glycerol-mediated promotion of somatic embryogenesis, which will open a new avenue for establishing a sophisticated system for somatic embryogenesis based on the modulation of endogenous polyamines. PMID:18448195

Wu, Xiao-Ba; Wang, Jing; Liu, Ji-Hong; Deng, Xiu-Xin

2009-01-01

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

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

PubMed Central

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

Zhou, Chenguang; Liu, Likun; Li, Chenghao

2014-01-01

90

Culture-induced variation in plants of Coffea arabica cv. Caturra rojo, regenerated by direct and indirect somatic embryogenesis  

Microsoft Academic Search

Amplified fragment-length polymorphism (AFLP) was used to evaluate the stability of DNA in regenerated plantlets of Coffea arabica obtained by direct (DSE) and indirect somatic embryogenesis (ISE). Cluster analysis using the unweighted pair-group method\\u000a (UPGMA), showed no specific grouping pattern related to the type of embryogenesis. These results suggest that the somatic\\u000a embryogenesis (SE) process has a mechanism for the

L. Felipe Sanchez-Teyer; Francisco Quiroz-Figueroa; Victor Loyola-Vargas; Diogenes Infante

2003-01-01

91

Somatic embryogenesis and plant regeneration from callus cultures of chickpea ( Cicer arietinum L.)  

Microsoft Academic Search

Somatic embryogenesis and plant regeneration were obtained from immature leaflet callus of chickpea. Numerous globular embryos developed on the surface of callus on Murashige and Skoog's (1962) medium containing 25 M 2,4-dichlorophenoxyacetic acid. These globular embryos differentiated into mature somatic embryos upon removal of 2,4-dichlorophenoxyacetic acid. The maturation of embryos was significantly affected by pH, photoperiod, abscisic acid and genotype.

K. S. Barna; A. K. Wakhlu

1993-01-01

92

Somatic Embryogenesis of Tylophora indica (Burm.f.) Merril., an Important Medicinal Plant  

Microsoft Academic Search

An efficient procedure has been developed for inducing somatic embryogenesis from mature leaves of Tylophora indica (Burm.f.) Merrill, an important medicinal plant. Leaf sections were initially cultured on Murashige and Skoog's (MS) medium supplemented with thidiazuron (TDZ) in addition with 2, 4-dichlorophenoxy acetic acid (2,4-D), particularly 0.5 µm TDZ along with 1.5 µm 2,4-D was very effective in inducing somatic

T. Chandrasekhar; T. Mohammad Hussain; G. Rama Gopal; J. V. Srinivasa Rao

2006-01-01

93

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

Microsoft Academic Search

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

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

1997-01-01

94

An efficient regeneration system via direct and indirect somatic embryogenesis for the medicinal tree Murraya koenigii  

Microsoft Academic Search

A reproducible protocol for direct and indirect somatic embryogenesis was established in a small aromatic tree, Murraya koenigii. Embryogenic callus was obtained from 90% zygotic embryonic axis (ZE) and 70% cotyledon (COT) explants in Murashige and Skoog\\u000a (MS) basal medium supplemented with 8.88 ?M 6-benzyladenine (BA) and 2.675 ?M ?-naphthaleneacetic acid (NAA). Globular somatic\\u000a embryos were induced and further matured from such

S. Paul; A. Dam; A. Bhattacharyya; T. K. Bandyopadhyay

2011-01-01

95

Involvement of Plant Hormones and Plant Growth Regulators on in vitro Somatic Embryogenesis  

Microsoft Academic Search

In spite of the importance attained by somatic embryogenesis and of the many studies that have been conducted on this developmental\\u000a process, there are still many aspects that are not fully understood. Among those features, the involvement of plant hormones\\u000a and plant growth regulators on deTermining the conversion of somatic onto embryogenic tissues, and on allowing progression\\u000a and maturation of

Víctor M. Jiménez

2005-01-01

96

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

Microsoft Academic Search

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

Giorgio Gambino; Daniele Di Matteo; Ivana Gribaudo

2009-01-01

97

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

PubMed Central

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

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

2014-01-01

98

Extracts of Marine cyanobacteria stimulated somatic embryogenesis of Daucus carota L  

Microsoft Academic Search

Twenty five strains of marine cyanobacteria were screened for their ability to promote carrot somatic embryogenesis. Hot water extracts prepared from 21 of these strains promoted plantlet formation. Extracts from four strains increased plantlet numbers to an average of over 3.7-fold. Dialysates and nondialysates of each of these extracts also increased plantlet formation. For extracts from filamentous cyanobacteria, Nostoc sp.

Hitoshi Wake; Hironori Umetsu; Yoshihiro Ozeki; Koichiro Shimomura; Tadashi Matsunaga

1991-01-01

99

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

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

Microsoft Academic Search

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

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

1997-01-01

102

Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland  

E-print Network

significantly lower for these lines as compared to the standard cultivar for cotton transformation, `Coker 312Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland cotton been achieved in several cotton lines (Gossypium hirsutum L.) from the Georgia and Pee Dee germplasm

Chee, Peng W.

103

Somatic embryogenesis from shoot tip and immature inflorescence of Phoenix dactylifera cv. Barhee  

Microsoft Academic Search

Summary  A method of clonal propagation via somatic embryogenesis of date palm, cultivar Barhee, which has potential for large scale commercial application as well as for developmental studies on embryos is described. Cultures were initiated from shoot tip and immature inflorescence explants, both of which were capable of development into embryogenic callus. When the embryogenic callus was cultured in liquid suspension

Shyamala Bhaskaran; Roberta H. Smith

1992-01-01

104

Alfalfa embryo production in airlift vessels via direct somatic embryogenesis  

Microsoft Academic Search

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

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

1994-01-01

105

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

PubMed

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

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

2005-08-01

106

Direct somatic embryogenesis from protoplasts of Citrus mitis Blanco.  

PubMed

Protoplasts isolated from embryogenic suspension cultures of Citrus mitis were cultured in a medium without any plant growth substances. Somatic embryos developed directly from protoplasts without an obvious intervening callus phase. As many as 1,800 somatic embryos developed from 4 ml of protoplast suspension (density 2×10(6)/ml) cultured for 35 days. Upon transferring the embryoids to medium with 1 mgl(-1) GA3, they developed into plant-lets. Rooted plantlets were obtained in 3 months after protoplast isolation. PMID:24240259

Sim, G E; Loh, C S; Goh, C J

1988-10-01

107

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

108

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

E-print Network

Plant CellReports (1992)11:122-125 Repetitive somatic embryogenesis from peanut cultures in liquid. A regenerationsystembasedon repetitive somaticembryogenesiswasdevelopedfor peanut(Arachis hypogaeaL.). Embryogenic Plantregenerationfromculturedtissuesof peanut hasbeenreportedsporadicallyfor nearly 15years. Most of the earlier reports described

Parrott, Wayne

109

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

PubMed Central

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

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

2011-01-01

110

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

Microsoft Academic Search

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

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

1997-01-01

111

Somatic embryogenesis and plant regeneration in Cedrela fissilis  

Microsoft Academic Search

Somatic embryos were obtained from immature zygotic embryos of Cedrela fissilis Well. (Meliaceae), after a culture period of 12 months, with regular subcultures every 6–8 weeks. Callus was developed on explants in 2 months\\u000a on Murashige and Skoog (MS) medium containing 2,4 dichlorophenoxyacetic acid (2,4-D) or picloram (PIC). When the calli were\\u000a transferred to fresh medium, embryogenic tissue appeared on

S. Vila; A. Gonzalez; H. Rey; L. Mroginski

2009-01-01

112

Screening of diploid Medicago sativa germplasm for somatic embryogenesis  

Microsoft Academic Search

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

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

1985-01-01

113

Loss of competence for glyoxysome formation during somatic embryogenesis in anise ( Pimpinella anisum L.) suspension cultures  

Microsoft Academic Search

Somatic embryogenesis in anise (Pimpinella anisum L.) suspension cultures induced by transfer to hormone-free growth medium may be synchronized by previous selection of cell aggregates with diameters between 100–240 µm. Around 80–90% of the embryoids are globular after 2–3 d, heart-shaped after 5–7 d and torpedo-shaped after 9 d. In embryogenic medium without source of carbon or with 20 mmol\\/l

R. A. Kudielka; R. R. Theimer

1983-01-01

114

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

115

Callus culture of Coronilla varia L. (crownvetch): plant regeneration through somatic embryogenesis  

Microsoft Academic Search

Callus culture and plant regeneration through somatic embryogenesis have been obtained in Coronilla varia. Media used were UM (25) supplemented with 2 mg\\/l 2,4-D followed by subculture on MS (18) containing 1 mg\\/l 2-iP and 0.1 mg\\/l IAA. Embryoids developed into complete plantlets on filter paper saturated with hormone-free MS medium.

Domenico Mariotti; Sergio Arcioni

1983-01-01

116

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

Microsoft Academic Search

Flow cytometry analyses were used to verify the ploidy stability of Quercus suber L. somatic embryogenesis process. Leaf explants of two adult cork oak trees (QsG0 and QsG5) of the North of Portugal were inoculated on MS medium with 2,4-D and zeatin. After 3 months, calluses with embryogenic structures were isolated and transferred to fresh MS medium without growth regulators and

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

2005-01-01

117

Somatic embryogenesis and plant regeneration from immature embryos of western larch  

Microsoft Academic Search

Somatic embryogenesis was initiated from immature embryos of western larch (Larix occidentalis Nutt.) on media containing 2,4-dichlorophenoxyacetic acid and N6- benzyladenine. The effects of explant type and ammonium nitrate and glutamine concentrations on initiation were tested. Although 21–93% of explants rendered cultures in various experiments, only 3% yielded sustainable embryogenic lines. Excised embryos at the early cotyledonary stage were optimal

R. Gail Thompson; Patrick von Aderkas

1992-01-01

118

Somatic embryogenesis and plant regeneration of northern red oak ( Quercus rubra L.)  

Microsoft Academic Search

A somatic embryogenesis protocol for plant regeneration of northern red oak (Quercus rubra) was established from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium\\u000a (MS) containing 3% sucrose, 0.24% Phytagel™, and various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) after 4 weeks of culture in darkness. A higher response (66%) of embryogenic callus was induced on 0.45 ?M 2,4-d.

G. Vengadesan; Paula M. Pijut

2009-01-01

119

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

PubMed Central

Embryogenesis in plants can commence from cells other than the fertilized egg cell. Embryogenesis initiated from somatic cells in vitro is an attractive system for studying early embryonic stages when they are accessible to experimental manipulation. Somatic embryogenesis in Arabidopsis offers the additional advantage that many zygotic embryo mutants can be studied under in vitro conditions. Two systems are available. The first employs immature zygotic embryos as starting material, yielding continuously growing embryogenic cultures in liquid medium. This is possible in at least 11 ecotypes. A second, more efficient and reproducible system, employing the primordia timing mutant (pt allelic to hpt, cop2, and amp1), was established. A significant advantage of the pt mutant is that intact seeds, germinated in 2,4-dichlorophenoxyacetic acid (2, 4-D) containing liquid medium, give rise to stable embryonic cell cultures, circumventing tedious hand dissection of immature zygotic embryos. pt zygotic embryos are first distinguishable from wild type at early heart stage by a broader embryonic shoot apical meristem (SAM). In culture, embryogenic clusters originate from the enlarged SAMs. pt somatic embryos had all characteristic embryo pattern elements seen in zygotic embryos, but with higher and more variable numbers of cells. Embryogenic cell cultures were also established from seedling, of other mutants with enlarged SAMs, such as clavata (clv). pt clv double mutants showed additive effects on SAM size and an even higher frequency of seedlings producing embryogenic cell lines. pt clv double mutant plants had very short fasciated inflorescence stems and additive effects on the number of rosette leaves. This suggests that the PT and CLV genes act in independent pathways that control SAM size. An increased population of noncommitted SAM cells may be responsible for facilitated establishment of somatic embryogenesis in Arabidopsis. PMID:9611173

Mordhorst, A P; Voerman, K J; Hartog, M V; Meijer, E A; van Went, J; Koornneef, M; de Vries, S C

1998-01-01

120

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

Microsoft Academic Search

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

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

1984-01-01

121

Co-Localization of ?-1,3-Glucanases and Callose During Somatic Embryogenesis in Cichorium  

PubMed Central

During direct somatic embryogenesis in leaves of Cichorium hybrid clone ‘474’, 38 kDa ?-1,3-glucanases are accumulated in the culture medium of the embryogenic hybrid to a higher level when compared with a non-embryogenic cultivar. In the same time, embryogenic cells were surrounded by a cell wall that was characterized by the presence of callose. This callosic deposition disappeared as embryos grew. Callose consisted of ?-1,3-glucan linkages and so represented a possible substrate for ?-1,3-glucanases. Using immunolocalization experiments, we demonstrated that from the three types of callose deposits observed during the culturing of Cichorium leaf explants, only the callose present in the walls surrounding reactivated cells seemed specifically related to somatic embryogenesis. Moreover, callose and the 38-kDa ?-1,3-glucanases were co-localized dispersed throughout the thick and swelled walls of reactivated cells and embryo cell walls. This suggests that callose and ?-1,3-glucanases are implicated in the process of somatic embryogenesis since they were always detected in or quite near embryogenic and embryo cell. This also suggested that ?-1,3-glucanases could be involved in the degradation of this callose. PMID:19517006

Grimault, Valérie; Helleboid, Stéphane; Vasseur, Jacques

2007-01-01

122

Somatic embryogenesis, maturation and DNA transfer in Pinus  

E-print Network

Embryogenic callus was initiated on two types of media supplemented with auxin and cytokinin using immature zygotic embryo explants of ten different sources of slash pine (Pinus elliottii Englem.). Callus induction began after 30 days. The callus...

Marek, Kimberly Ann

1994-01-01

123

Influence of external factors on secondary embryogenesis and germination in somatic embryos from leaves of Quercus suber  

Microsoft Academic Search

Somatic embryogenesis was obtained in cultures of leaves from young seedlings of Quercus suber L. A two-stage process, in which benzyladenine and naphthaleneacetic acid were added first at high and then at low concentrations, was required to initiate the process. Somatic embryos arose when the explants were subsequently placed on medium lacking plant growth regulators. The embryogenic lines remained productive,

Bárbara Fernández-Guijarro; Cristina Celestino; Mariano Toribio

1995-01-01

124

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

Microsoft Academic Search

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

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

1991-01-01

125

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

Microsoft Academic Search

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

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

2001-01-01

126

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

Microsoft Academic Search

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

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

1996-01-01

127

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

PubMed

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

Thompson, R G; von Aderkas, P

1992-07-01

128

Conifer somatic embryogenesis: improvements by supplementation of medium with oxidation-reduction agents.  

PubMed

A major barrier to the commercialization of somatic embryogenesis technology in loblolly pine (Pinus taeda L.) is recalcitrance of some high-value crosses to initiate embryogenic tissue (ET) and continue early-stage somatic embryo growth. Developing initiation and multiplication media that resemble the seed environment has been shown to decrease this recalcitrance. Glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid and dehydroascorbate analyses were performed weekly throughout the sequence of seed development for female gametophyte and zygotic embryo tissues to determine physiological concentrations. Major differences in stage-specific oxidation-reduction (redox) agents were observed. A simple bioassay was used to evaluate potential growth-promotion of natural and inorganic redox agents added to early-stage somatic embryo growth medium. Compounds showing statistically significant increases in early-stage embryo growth were then tested for the ability to increase initiation of loblolly pine. Low-cost reducing agents sodium dithionite and sodium thiosulfate increased ET initiation for loblolly pine and Douglas fir (Mirb) Franco. Germination medium supplementation with GSSG increased somatic embryo germination. Early-stage somatic embryos grown on medium with or without sodium thiosulfate did not differ in GSH or GSSG content, suggesting that sodium thiosulfate-mediated growth stimulation does not involve GSH or GSSG. We have developed information demonstrating that alteration of the redox environment in vitro can improve ET initiation, early-stage embryo development and somatic embryo germination in loblolly pine. PMID:25716878

Pullman, Gerald S; Zeng, Xiaoyan; Copeland-Kamp, Brandi; Crockett, Jonathan; Lucrezi, Jacob; May, Sheldon W; Bucalo, Kylie

2015-02-01

129

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

PubMed

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

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

2015-03-01

130

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

131

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

PubMed

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

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

2009-05-01

132

Somatic embryogenesis and plant regeneration in zygotic embryos of Trifolium nigrescens (Viv.)  

Microsoft Academic Search

This study developed a plant regeneration protocol for Trifolium nigrescens (Viv.) via somatic embryogenesis (SE). Immature zygotic embryos at torpedo (TsE) and cotyledonary (CsE) stage were cultured on media\\u000a with different auxins and cytokinins at different concentrations. The cultural requirements for SE differed between the explants\\u000a used: the addition of 6-furfurylaminopurine (kinetin) or N6-[2-isopentenyl]-adenine (2iP) along with 2,4-dihydrophenoxyacetic acid (2,4-D)

Robert Konieczny; Maria Pilarska; Monika Tuleja; Terezia Salaj; Tomasz Ilnicki

2010-01-01

133

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

Microsoft Academic Search

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

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

1997-01-01

134

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

Microsoft Academic Search

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

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

1998-01-01

135

Large impact of the apoplast on somatic embryogenesis in Cyclamen persicum offers possibilities for improved developmental control in vitro  

PubMed Central

Background Clonal propagation is highly desired especially for valuable horticultural crops. The method with the potentially highest multiplication rate is regeneration via somatic embryogenesis. However, this mode of propagation is often hampered by the occurrence of developmental aberrations and non-embryogenic callus. Therefore, the developmental process of somatic embryogenesis was analysed in the ornamental crop Cyclamen persicum by expression profiling, comparing different developmental stages of embryogenic cell cultures, zygotic vs. somatic embryos and embryogenic vs. non-embryogenic cell cultures. Results The analysis was based on a cDNA microarray representing 1,216 transcripts and was exemplarily validated by realtime PCR. For this purpose relative transcript abundances of homologues of a putative receptor kinase, two different glutathione S-transferases (GST), a xyloglucan endotransglycosylase (XET) and a peroxidase (POX) were quantitatively measured by realtime PCR for three different comparisons. In total, 417 genes were found to be differentially expressed. Gene Ontology annotation revealed that transcripts coding for enzymes that are active in the extracellular compartment (apoplast) were significantly overrepresented in several comparisons. The expression profiling results are underpinned by thorough histological analyses of somatic and zygotic embryos. Conclusions The putative underlying physiological processes are discussed and hypotheses on improvement of the protocol for in vitro somatic embryogenesis in Cyclamen persicum are deduced. A set of physiological markers is proposed for efficient molecular control of the process of somatic embryogenesis in C. persicum. The general suitability of expression profiling for the development and improvement of micropropagation methods is discussed. PMID:20426818

2010-01-01

136

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

Microsoft Academic Search

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

R. Schuchmann; E. Wellmann

1983-01-01

137

High efficiency plant production of North American ginseng via somatic embryogenesis from cotyledon explants  

Microsoft Academic Search

An efficient in vitro protocol for plant production of North American ginseng has been established. The pretreatment of cotyledon\\u000a explants with 1.0 M sucrose at 4°C resulted in an improvement of embryo quality and, combined with a higher sucrose content\\u000a (7%) in induction medium, improved the embryogenesis frequency from 40% to 75% and the number of embryos per explant from\\u000a 10

Sijun Zhou; Daniel C. W. Brown

2006-01-01

138

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

PubMed

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

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

2000-01-01

139

Somatic embryogenesis in Solanum tuberosum from cell suspension cultures: histological analysis and extracellular protein patterns.  

PubMed

An embryogenic cell suspension, continuously grown in Murashige and Skoog (MS) medium with 0.5 mg/L of 2,4-dichlorophenoxyacetic acid, was established from friable callus of Solanum tuberosum internode sections. The cell suspension was predominantly composed of cell masses and free embryogenic cells. When transferred to an auxin-free medium with zeatin, somatic embryos (SEs) developed and converted to complete plants when cultured on solid MS medium without growth regulators. The system produced approximately 600 SEs per 50 mL of medium. In this investigation, accumulation of extracellular proteins (EPs) of different molecular weights were found associated to different phases of the embryogenic process. At the initiation of the cell suspension, cell clusters and free cells present in the culture (phase "A") secreted a 78kDa EP, unique to this phase. In phase "B", which is related to embryonic cell determination process, proteins (7-14kDa) were secreted mainly by embryogenic cells. In phase "C", SEs in different developmental stages secreted protein of 32 kDa, which appeared as a particular feature of the phase. EPs of phase "D", secreted by torpedo and mature embryos, had molecular weights between 20 and 50 kDa. Further studies will be necessary to identify these proteins and link them to previously identified somatic embryogenesis-related proteins. Histological analysis of the potato embryogenesis in liquid media showed unicellular origin of the SE. PMID:15900887

Vargas, Teresa E; De García, Eva; Oropeza, Maira

2005-04-01

140

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

141

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

Microsoft Academic Search

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

S. Kintzios; A. Nikolaou; M. Skoula

1999-01-01

142

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

143

Stimulation of somatic embryogenesis and plant regeneration from anther culture of Vitis vinifera cv. Cabernet-Sauvignon  

Microsoft Academic Search

Somatic embryogenesis and subsequent diploid plants have been obtained from anthers of Vitis vinifera Cabernet-Sauvignon, a cultivar so far considered as recalcitrant to in vitro regeneration. Anthers enclosing microspores near the first pollen mitosis were found to be the most responsive. However, from a practical point of view anther length proved to be an easier criterium for determining the optimal

M. Cl. Mauro; C. Nef; J. Fallot

1986-01-01

144

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. ...

145

TDZ-induced direct shoot organogenesis and somatic embryogenesis on cotyledonary node explants of lentil (Lens culinaris Medik.).  

PubMed

An efficient and simple procedure for inducing high frequency direct shoot organogenesis and somatic embryogenesis in lentil from cotyledonary node explants (without both the cotyledons) in response to TDZ alone is reported. TDZ at concentration lower than 2.0 ?M induced shoot organogenesis whereas at higher concentration (2.5-15 ?M) it caused a shift in regeneration from shoot organogenesis to somatic embryogenesis. The cotyledonary node and seedling cultures developed only shoots even at high concentrations of BAP and TDZ, respectively. TDZ at 0.5 and 5.0 ?M was found to be optimal for inducing an average of 4-5 shoots per cotyledonary node in 93 % of the cultures and 55 somatic embryos in 68 % of the cultures, respectively. The somatic embryos were germinated when transferred to lower TDZ concentration (0.5-1.0 ?M). The shoots were rooted on MS basal medium containing 2.5 ?M IBA. The plantlets were obtained within 8 weeks from initiation of culture and were morphologically similar to seed-raised plants. The possible role of stress in thidiazuron induced somatic embryogenesis is discussed. PMID:23572901

Chhabra, Gulshan; Chaudhary, Darshna; Varma, Madan; Sainger, Manish; Jaiwal, Pawan K

2008-10-01

146

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

PubMed

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

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

2011-11-01

147

Developmental Plasticity of Glandular Trichomes into Somatic Embryogenesis in Tilia amurensis  

PubMed Central

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

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

2007-01-01

148

The relationship between induction of embryogenesis and chromosome doubling in microspore cultures  

Microsoft Academic Search

Summary.  The objective of this paper is to review the relationship between induction of microspore embryogenesis and chromosome doubling.\\u000a It has been augmented with relative data on chromosome doubling by nuclear fusion. Some of the treatments used for induction\\u000a of embryogenesis may also lead to doubling of the chromosome number, either through nuclear fusion or endomitosis. High frequencies\\u000a of spontaneous chromosome

Y. S. Shim; K. J. Kasha; E. Simion; J. Letarte

2006-01-01

149

Somatic embryogenesis in leaf callus from a mature Quercus suber L. Tree  

Microsoft Academic Search

Summary  Somatic embryos were obtained from a 60-yr-old Quercus suber L. tree. Leaf explants were cultivated on Murashige and Skoog medium with 30 gl?1 sucrose, 3 gl?1 gelrite, pH adjusted to 5.8, and different growth regulator combinations. Callus induction took place at 241C in the dark\\u000a during the first 3 wk. After 3 mo, calluses that showed embryogenic structures were transferred

Glória Pinto; Helena Valentim; Armando Costa; Sílvia Castro; Conceiçăo Santos

2002-01-01

150

High-frequency regeneration via somatic embryogenesis of an elite recalcitrant cotton genotype ( Gossypium hirsutum L.) and efficient Agrobacterium -mediated transformation  

Microsoft Academic Search

A highly efficient and reproducible regeneration system based on somatic embryogenesis in Gossypium hirsutum cv. Narasimha (NM), which has superior fiber qualities and is also used as a female parent in several hybrid cottons, has\\u000a been developed. Embryogenic callus was obtained form both hypocotyls and cotyledonary leaves on Murashige and Skoog (MS) medium\\u000a containing kinetin and 2,4-dichlorophenoxyacetic acid. Somatic embryogenesis

Tanveer Khan; Vanga Siva Reddy; Sadhu Leelavathi

2010-01-01

151

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

Microsoft Academic Search

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

M. Gallo-Meagher; J. Green

2002-01-01

152

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

153

Bioreactor studies of the effect of medium pH on carrot (Daucus carota L.) somatic embryogenesis  

Microsoft Academic Search

Daucus carota cell differentiation was examined under different medium pH conditions in a controlled bioreactor. Somatic embryogenesis was affected by pH changes. Embryo production was greatest when the pH of the hormone-free medium was maintained at 4.3. However, the same level was not favourable to development since most embryos did not progress to the torpedo and plantlet stages. In contrast,

Véronique Jay; Simone Genestier; Jean-Claude Courduroux

1994-01-01

154

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

Microsoft Academic Search

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

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

1993-01-01

155

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

156

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

PubMed Central

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

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

2007-01-01

157

A chimeric arabinogalactan protein promotes somatic embryogenesis in cotton cell culture.  

PubMed

Arabinogalactan proteins (AGPs) are a family of extracellular plant proteoglycans implicated in many aspects of plant growth and development, including in vitro somatic embryogenesis (SE). We found that specific AGPs were produced by cotton (Gossypium hirsutum) calli undergoing SE and that when these AGPs were isolated and incorporated into tissue culture medium, cotton SE was promoted. When the AGPs were partly or fully deglycosylated, SE-promoting activity was not diminished. Testing of AGPs separated by reverse-phase high-performance liquid chromatography revealed that the SE-promoting activity resided in a hydrophobic fraction. We cloned a full-length complementary DNA (cotton PHYTOCYANIN-LIKE ARABINOGALACTAN-PROTEIN1 [GhPLA1]) that encoded the protein backbone of an AGP in the active fraction. It has a chimeric structure comprising an amino-terminal signal sequence, a phytocyanin-like domain, an AGP-like domain, and a hydrophobic carboxyl-terminal domain. Recombinant production of GhPLA1 in tobacco (Nicotiana tabacum) cells enabled us to purify and analyze a single glycosylated AGP and to demonstrate that this chimeric AGP promotes cotton SE. Furthermore, the nonglycosylated phytocyanin-like domain from GhPLA1, which was bacterially produced, also promoted SE, indicating that the glycosylated AGP domain was unnecessary for in vitro activity. PMID:22858635

Poon, Simon; Heath, Robyn Louise; Clarke, Adrienne Elizabeth

2012-10-01

158

Plant regeneration through somatic embryogenesis from tissues of mature oak trees: true-to-type conformity of plantlets by RAPD analysis  

Microsoft Academic Search

Somatic embryogenesis was induced in expanding leaf explants excised from epicormic shoots forced from branch segments taken at four different times of year from a mature oak (Quercus robur L.). Branch segments 2–4 cm in diameter produced most shoots when collected in March. Somatic embryos were induced on explants derived from branches of all collection dates, although collection in November seemed

S. Valladares; C. Sánchez; M. T. Martínez; A. Ballester; A. M. Vieitez

2006-01-01

159

First Report of Plant Regeneration via Somatic Embryogenesis from Shoot Apex-Derived Callus of Hedychium muluense R.M. Smith  

Microsoft Academic Search

The genus Hedychium consists of about 50 species, with increasing popularity as ornamentals and potential as medicinal crop plants, but there are no reports on somatic embryogenic regeneration of any member of this genus. The objective of this investigation was to establish an in vitro regeneration system based on somatic embryogenesis for Hedychium muluense R.M. Smith using shoot apex-derived callus.

Hamidou F. Sakhanokho; Rowena Y. Kelley; Kanniah Rajasekaran

2008-01-01

160

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

PubMed

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

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

2014-01-15

161

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

PubMed Central

Plant cells have the capacity to generate a new plant without egg fertilization by a process known as somatic embryogenesis (SE), in which differentiated somatic cells can form somatic embryos able to generate a functional plant. Although there have been advances in understanding the genetic basis of SE, the epigenetic mechanism that regulates this process is still unknown. Here, we show that the embryogenic development of Coffea canephora proceeds through a crosstalk between DNA methylation and histone modifications during the earliest embryogenic stages of SE. We found that low levels of DNA methylation, histone H3 lysine 9 dimethylation (H3K9me2) and H3K27me3 change according to embryo development. Moreover, the expression of LEAFY COTYLEDON1 (LEC1) and BABY BOOM1 (BBM1) are only observed after SE induction, whereas WUSCHEL-RELATED HOMEOBOX4 (WOX4) decreases its expression during embryo maturation. Using a pharmacological approach, it was found that 5-Azacytidine strongly inhibits the embryogenic response by decreasing both DNA methylation and gene expression of LEC1 and BBM1. Therefore, in order to know whether these genes were epigenetically regulated, we used Chromatin Immunoprecipitation (ChIP) assays. It was found that WOX4 is regulated by the repressive mark H3K9me2, while LEC1 and BBM1 are epigenetically regulated by H3K27me3. We conclude that epigenetic regulation plays an important role during somatic embryogenic development, and a molecular mechanism for SE is proposed. PMID:23977240

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

2013-01-01

162

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

PubMed

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

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

2010-11-01

163

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

164

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

Microsoft Academic Search

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

D. J. Gray; J. A. Mortensen

1987-01-01

165

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

166

A Lower pH Value Benefits Regeneration of Trichosanthes kirilowii by Somatic Embryogenesis, Involving Rhizoid Tubers (RTBs), a Novel Structure  

PubMed Central

A new approach was established for the regeneration of Trichosanthes kirilowii from root, stem, and leaf explants by somatic embryogenesis (SE), involving a previously unreported SE structure, rhizoid tubers (RTBs). During SE, special rhizoids were first induced from root, stem, and leaf explants with average rhizoid numbers of 62.33, 40.17, and 11.53 per explant, respectively, on Murashige and Skoog (MS) medium (pH 4.0) supplemented with 1.0?mg/L 1-naphthaleneacetic acid (NAA) under dark conditions. Further, one RTB was formed from each of the rhizoids on MS medium (pH 4.0) supplemented with 20?mg/L thidiazuron (TDZ) under light conditions. In the suitable range (pH 4.0–9.0), a lower pH value increased the induction of rhizoids and RTBs. Approximately 37.77, 33.47, and 31.07% of in vivo RTBs from root, stem, and leaf explants, respectively, spontaneously developed into multiple plantlets on the same MS medium (supplemented with 20?mg/L TDZ) for induction of RTBs, whereas >95.00% of in vitro RTBs from each kind of explant developed into multiple plantlets on MS medium supplemented with 5.0?mg/L 6-benzylaminopurine (BAP). Morphological and histological analyses revealed that RTB is a novel type of SE structure that develops from the cortex cells of rhizoids. PMID:25744384

Xu, Ke-dong; Chang, Yun-xia; Zhang, Ju; Wang, Pei-long; Wu, Jian-xin; Li, Yan-yan; Wang, Xiao-wen; Wang, Wei; Liu, Kun; Zhang, Yi; Yu, De-shui; Liao, Li-bing; Li, Yi; Ma, Shu-ya; Tan, Guang-xuan; Li, Cheng-wei

2015-01-01

167

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

PubMed Central

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

2011-01-01

168

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

169

Improved efficiency and normalization of somatic embryogenesis in Triticum aestivum (wheat)  

Microsoft Academic Search

Summary Tissue cultures derived from the scutellum of immature embryos ofTriticum aestivum L. (wheat) gave rise to somatic embryos with a well-defined scutellum and coleoptile as well as one or more shoot primordia and a root primordium. The normal somatic embryos were formed from compact, white callus tissue which was not observed until 4 or more weeks after culture initiation.

Peggy Ozias-Akins; Indra K. Vasil

1983-01-01

170

Developmental patterns during direct somatic embryogenesis in protoplast cultures of european larch ( Larix decidua Mill.)  

Microsoft Academic Search

Protoplasts isolated from embryogenic suspension cultures of European larch (Larix decidua Mill.) were cultured in thin alginate layers using a nylon mesh to enable a monitoring of the development of single cells. The patterns of cell division and differentiation are characterized and compared with zygotic embryogenesis to which homologies can only be drawn to some extent when the protoplasts grow

Jonas Korlach; Kurt Zoglauer

1995-01-01

171

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

172

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

PubMed

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

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

2014-03-01

173

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

174

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

PubMed Central

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

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

2001-01-01

175

GhHmgB3 deficiency deregulates proliferation and differentiation of cells during somatic embryogenesis in cotton.  

PubMed

The proteins of high-mobility group box (HmgB) family were involved in the regulation of transcription and other DNA-dependent processes. To investigate the function of HmgB proteins during cotton somatic embryogenesis (SE), four Gossypium hirsutum HmgB genes were characterized. The gene GhHmgB3 preferentially expressed in embryonic tissues and was studied in detail. RNA interference and over-expression was used to regulate the expression of GhHmgB3 during cotton SE by transforming both hypocotyl and embryogenic calli (ECs) via Agrobacterium tumefaciens. The GhHmgB3-deficient somatic cells of hypocotyls dedifferentiated more vigorously than the control cells, but they failed to differentiate to ECs. In another case, the proliferation and differentiation of GhHmgB3-deficient ECs were significantly improved, but failed to form plantlets. Over-expression of GhHmgB3 had no significant differences in callus initiation and differentiation compared with the control cell lines. The different expression genes between the control and GhHmgB3-deficient ECs were identified by Solexa sequencing technology. The bioinformatics analysis and experimental verification revealed series of abnormal mechanism associated with ?-catenin signalling. These results in response to the down-regulation of GhHmgB3 revealed series of ?-catenin-related mechanisms might be responsible for the deregulation of proliferation and differentiation of cells in cotton SE. PMID:21554528

Hu, Lisong; Yang, Xiyan; Yuan, Daojun; Zeng, Fanchang; Zhang, Xianlong

2011-12-01

176

Stress induced somatic embryogenesis in carrot and its application to synthetic seed production  

Microsoft Academic Search

Summary  When apical meristems of carrot (Daucus carota L. cv. US-Harumakigosun) seedlings were cultured on hormone-free Murashige and Skoog’s (MS) medium with 0.7 M sucrose or\\u000a 0.25–1 mM cadmium ion, then transferred to hormone-free MS medium with 0.1 M sucrose, somatic embryos were formed on the surface\\u000a of the explants without visible callus formation. Somatic embryos were also formed on malformed

Hiroshi Kamada; Katsunori Kobayashi; Tomohiro Kiyosue; Hiroshi Harada

1989-01-01

177

Direct somatic embryogenesis from pericycle cells of broccoli ( Brassica oleracea L. var. italica) root explants  

Microsoft Academic Search

Cotyledon, hypocotyl or root explants of 7-day-old broccoli seedlings were cultured on Murashige and Skoog (MS) agar or liquid\\u000a medium supplemented with 1.0 mg l?1 2,4-dichlorophenoxyacetic acid (2,4-D). The frequency of direct somatic embryo formation was 100% when root explants were\\u000a cultured in liquid medium. Histological analysis indicated that somatic embryos were initiated directly from the pericycle\\u000a cell layers of root explants

J. L. Yang; E. S. Seong; M. J. Kim; B. K. Ghimire; W. H. Kang; Chang Yeon Yu; Cheng Hao Li

2010-01-01

178

Plant regeneration via somatic embryogenesis from protoplasts of six plant species related to Citrus.  

PubMed

Protoplasts isolated from embryogenic callus of Fortunella polyandra (Ridl.), Atalantia bilocularis (Pieree ex Guill.), Hesperethusa crenulata (Roxb.), Glycosmis pentaphylla (Retz.) Corr., Triphasia trifolia (Burm. f.) P. Wils. and Murraya koenigii (L.) Spreng. were cultured in MT (Murashige and Tucker 1969) basal medium containing 5% sucrose supplemented with 0.0, 0.001, 0.01, 0.1 or 1.0 mg l(-1) BA and 0.6 M sorbitol. The highest plating efficiencies for all species were obtained on MT basal medium containing 5% sucrose supplemented with 0.001 mg l(-1) BA. F. polyandra produced higher percentages of globular somatic embryo development, while A. bilocularis consistently showed a lower percentage of globular somatic embryo development in all 5 concentrations of BA. MT basal medium containing 5% sucrose and supplemented with 0.001 mg l(-1) BA was found to be a suitable medium for development of globular somatic embryos derived from protoplasts to form heart-shaped somatic embryos with cotyledon-like structures. The highest percentages of shoot formation for all 6 species were obtained using 0.1 mg l(-1) GA3. A complete protoplast-to-plant system was developed for F. polyandra, A. bilocularis and T. trifolia, which could facilitate the transfer of nuclear and cytoplasmic genes from these species into cultivated Citrus through protoplast fusion. PMID:24178352

Jumin, H B; Nito, N

1996-01-01

179

Somatic embryogenesis from leaf callus derived from mature trees of the cycad Ceratozamia hildae (Gymnospermae)  

Microsoft Academic Search

A friable and transient embryogenic callus was initiated from pinnae removed from leaves in new vegetative flushes of mature Ceratozamia hildae Landry & Wilson, a cycad. Somatic proembryos developed from the callus approximately 3 months after explanting onto plant growth medium consisting of a modified B5 formulation with 60 g l-1 sucrose, 400 mg l-1 glutamine, 100 mg l-1 arginine,

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

1995-01-01

180

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

181

A novel regeneration system for a wild passion fruit species ( Passiflora cincinnata Mast.) based on somatic embryogenesis from mature zygotic embryos  

Microsoft Academic Search

The objective of the present work was to induce somatic embryogenesis from zygotic embryos of Passiflora cincinnata Masters. Zygotic embryos formed calli on media with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and\\u000a 4.5 ?M benzyladenine (BA) after 30 days of in vitro culture. A concentration of 18.1 ?M 2,4-D resulted in the largest number\\u000a of somatic embryos. Embryogenic calli were yellowish and friable,

Maurecilne Lemes da Silva; Daniela Lopes Paim Pinto; Miguel Pedro Guerra; Eny Iochevet Segal Floh; Cláudio Horst Bruckner; Wagner Campos Otoni

2009-01-01

182

Promotive and inhibitory effects of diverse arabinogalactan proteins on Daucus carota L. somatic embryogenesis  

Microsoft Academic Search

.   Secreted arabinogalactan proteins (AGPs), isolated on the basis of specific epitopes, have been reported that can either\\u000a enhance (ZUM18 AGP fraction) or inhibit (ZUM15 AGP fraction) carrot (Daucus carota L.) somatic embryo development (Kreuger and van Holst, 1995, Planta 197: 135–141). Here, we report that addition of the ZUM18\\u000a AGP fraction to different size-fractionated cell populations isolated from embryogenic

Marcel A. J. Toonen; Ed D. L. Schmidt; Ab van Kammen; Sacco C. de Vries

1997-01-01

183

Somatic embryogenesis and plant regeneration from litchi protoplasts isolated from embryogenic suspensions  

Microsoft Academic Search

High yields of protoplasts were isolated from litchi embryogenic suspensions, which were maintained by alternative culture\\u000a in liquid and on solid media containing silver thiosulfate. Protoplasts in liquid culture and agarose beads were unable to\\u000a divide sustainedly, whereas embedding of protoplasts in Ca-alginate supported cell division to microcalli and the direct formation\\u000a of somatic embryos from protoplasts. Nurse cells of

Changhe Yu; Zhenguang Chen; Liuxin Lu; Jinwen Lin

2000-01-01

184

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

185

Somatic embryogenesis and plant regeneration in Coronilla varia L. (crownvetch) long-term tissue cultures  

Microsoft Academic Search

Spontaneous recovery of regeneration abilities was observed in a long-term (about two-year-old) crownvetch (Coronilla varia L.) tissue culture permanently grown on MS medium containing 1 mg 1-1 IAA. Somatic embryos and later complete plants differentiated from initially regenerating roots. The formation and development\\u000a of embryos was accompanied by a 10- to 20-fold increase in the content of cardioactive glycosides hyrcanoside

Ji?ina Duškova; Z. Opatrný; Marie Sovová; J. Dušek

1990-01-01

186

Influence of 50 Hz electromagnetic fields on recurrent embryogenesis and germination of cork oak somatic embryos  

Microsoft Academic Search

Plant tissue culture techniques are carried out under environmentally controlled conditions in phytotrons. However, electric\\u000a components of phytotrons generate electromagnetic fields that may act as a environmental factor influencing plant growth and\\u000a morphogenesis. Isolated somatic embryos of Quercus suber, picked from embryogenic lines, were chronically exposed to a 50\\u000a Hz and 15 ?T electromagnetic field generated in a Helmholtz-coil system

Cristina Celestino; Maria Luisa Picazo; Mariano Toribio; Jose Antonio Alvarez-Ude; Jose Luis Bardasano

1998-01-01

187

Somatic embryogenesis from leaf and zygotic embryo explants of Blighia sapida ‘Cheese’ ackee  

Microsoft Academic Search

Summary  This study investigated factors affecting the production of somatic embryos in Blighia sapida (ackee). Explants obtained from fully expanded leaves or cotyledons of immature zygotic embryos excised from brown (BSCZE)\\u000a or green seeds (GSCZE) were cultured on Murashige and Skoog medium supplemented with 9, 18 and 36?M 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4 or 22.1 ?M benzylaminopurine (BAP) or 0.2–19.9 ?M

S. A. Webster; S. A. Mitchell; W. A. Reid; M. H. Ahmad

2006-01-01

188

Somatic Embryogenesis from Hairy Roots Transformed by Agrobacterium Rhizogenes in Panax Ginseng  

Microsoft Academic Search

An efficient in vitro protocol for somatic embryo- genesis of hairy roots of Panxa ginseng has been established. Hairy roots of Panax ginseng were obtained after root disks were infected with Agrobacterium rhizogenes A4. Callus was induced on MS (Murashige and Skoog 1962) medium containing 2,4-D (2,4-Dichlorophenoxyacetic acid), BA (6-Benzyl-aminopurine), Kin (Kinetin). The highest frequency of callus formation was 99.3%

Wang Jianhua; Zhao Shoujing; Xue Jian; Xu Lixin; Hou Chunxi; Liang Yanlong

2008-01-01

189

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

Microsoft Academic Search

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

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

1992-01-01

190

Plant regeneration from cultured immature inflorescences of coconut ( Cocos nucifera L.): evidence for somatic embryogenesis  

Microsoft Academic Search

Immature inflorescences of coconut belonging to three different genotypes were cultured on a solid medium supplemented with activated charcoal (2%) and a range of 2,4-dichlorophenoxyacetic acid (2,4-D) concentrations (from 1.5 to 3.5 × 10-4M). Globular white callus formed from immature floral meristems, depending on inflorescence age and 2,4-D concentration. Acquisition of embryogenic competence is described histologically. Somatic embryos presented a

Jean-Luc Verdeil; Christine Huet; Frédérique Grosdemange; Jacqueline Buffard-Morel

1994-01-01

191

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

192

Somatic embryogenesis in suspension and suspension-derived callus cultures of Dactylis glomerata  

Microsoft Academic Search

Summary Suspension cultures were initiated from somatic embryos and embryogenic callus ofDactylis glomerata L. in SH-30 liquid medium [Schenk andHildebrandt (1972) containing 30 µM 3,6-dichloro-o-anisic acid (dicamba)] with or without 1.5 gl-1 casein hydrolysate. Established suspension cultures maintained in SH-30 without casein hydrolysate proliferated when cell masses underwent cell division and enlargement. These cultures contained numerous root primordia and increased

D. J. Gray; B. V. Conger; G. E. Hanning

1984-01-01

193

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

Microsoft Academic Search

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

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

1996-01-01

194

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

Microsoft Academic Search

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

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

1990-01-01

195

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

196

Deep Sequencing and Microarray Hybridization Identify Conserved and Species-Specific MicroRNAs during Somatic Embryogenesis in Hybrid Yellow Poplar  

PubMed Central

Background To date, several studies have indicated a major role for microRNAs (miRNAs) in regulating plant development, but miRNA-mediated regulation of the developing somatic embryo is poorly understood, especially during early stages of somatic embryogenesis in hardwood plants. In this study, Solexa sequencing and miRNA microfluidic chips were used to discover conserved and species-specific miRNAs during somatic embryogenesis of hybrid yellow poplar (Liriodendron tulipifera×L. chinense). Methodology/Principal Findings A total of 17,214,153 reads representing 7,421,623 distinct sequences were obtained from a short RNA library generated from small RNAs extracted from all stages of somatic embryos. Through a combination of deep sequencing and bioinformatic analyses, we discovered 83 sequences with perfect matches to known miRNAs from 33 conserved miRNA families and 273 species-specific candidate miRNAs. MicroRNA microarray results demonstrated that many conserved and species-specific miRNAs were expressed in hybrid yellow poplar embryos. In addition, the microarray also detected another 149 potential miRNAs, belonging to 29 conserved families, which were not discovered by deep sequencing analysis. The biological processes and molecular functions of the targets of these miRNAs were predicted by carrying out BLAST search against Arabidopsis thaliana GenBank sequences and then analyzing the results with Gene Ontology. Conclusions Solexa sequencing and microarray hybridization were used to discover 232 candidate conserved miRNAs from 61 miRNA families and 273 candidate species-specific miRNAs in hybrid yellow poplar. In these predicted miRNAs, 64 conserved miRNAs and 177 species-specific miRNAs were detected by both sequencing and microarray hybridization. Our results suggest that miRNAs have wide-ranging characteristics and important roles during all stages of somatic embryogenesis in this economically important species. PMID:22952685

Qiu, Shuai; Zhang, Yanjuan; Wang, Pengkai; Yang, Liwei; Lu, Ye; Shi, Jisen

2012-01-01

197

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

198

Somatic embryogenesis and plant regeneration from cultured young inflorescences of Oryza sativa L. (rice)  

Microsoft Academic Search

Compact calli initiated from young inflorescences of Oryza sativa L. (rice) on the Linsmaier and Skoog's (LS) medium containing 1 to 2.5mg\\/l of 2,4-dichlorophen-oxyacetic acid (2,4-D) were\\u000a used for regeneration studies. After smooth and compact nodules appeared, these calli were transferred to the regeneration\\u000a medium containing indole-3-acetic acid (IAA) and either kinetin or 6-benzylaminopurine (BAP). Somatic embryos developed in\\u000a ten

Tsung-Hsien Chen; Ling Lam; Shuh-Chun Chen

1985-01-01

199

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

PubMed Central

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

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

2012-01-01

200

The union of somatic gonad precursors and primordial germ cells during C. elegans embryogenesis  

PubMed Central

Somatic gonadal niche cells control the survival, differentiation, and proliferation of germline stem cells. The establishment of this niche-stem cell relationship is critical, and yet the precursors to these two cell types are often born at a distance from one another. The simple C. elegans gonadal primordium, which contains two somatic gonad precursors (SGPs) and two primordial germ cells (PGCs), provides an accessible model for determining how stem cell and niche cell precursors first assemble during development. To visualize the morphogenetic events that lead to formation of the gonadal primordium, we generated transgenic strains to label the cell membranes of the SGPs and PGCs and captured time-lapse movies as the gonadal primordium formed. We identify three distinct phases of SGP behavior: posterior migration along the endoderm towards the PGCs, extension of a single long projection around the adjacent PGC, and a dramatic wrapping over the PGC surfaces. We show that the endoderm and PGCs are dispensable for SGP posterior migration and initiation of projections. However, both tissues are required for the final positioning of the SGPs and the morphology of their projections, and PGCs are absolutely required for SGP wrapping behaviors. Finally, we demonstrate that the basement membrane component laminin, which localizes adjacent to the developing gonadal primordium, is required to prevent the SGPs from over-extending past the PGCs. Our findings provide a foundation for understanding the cellular and molecular regulation of the establishment of a niche-stem cell relationship. PMID:23562590

Rohrschneider, Monica R.; Nance, Jeremy

2013-01-01

201

The union of somatic gonad precursors and primordial germ cells during Caenorhabditis elegans embryogenesis.  

PubMed

Somatic gonadal niche cells control the survival, differentiation, and proliferation of germline stem cells. The establishment of this niche-stem cell relationship is critical, and yet the precursors to these two cell types are often born at a distance from one another. The simple Caenorhabditis elegans gonadal primordium, which contains two somatic gonad precursors (SGPs) and two primordial germ cells (PGCs), provides an accessible model for determining how stem cell and niche cell precursors first assemble during development. To visualize the morphogenetic events that lead to formation of the gonadal primordium, we generated transgenic strains to label the cell membranes of the SGPs and PGCs and captured time-lapse movies as the gonadal primordium formed. We identify three distinct phases of SGP behavior: posterior migration along the endoderm towards the PGCs, extension of a single long projection around the adjacent PGC, and a dramatic wrapping over the PGC surfaces. We show that the endoderm and PGCs are dispensable for SGP posterior migration and initiation of projections. However, both tissues are required for the final positioning of the SGPs and the morphology of their projections, and PGCs are absolutely required for SGP wrapping behaviors. Finally, we demonstrate that the basement membrane component laminin, which localizes adjacent to the developing gonadal primordium, is required to prevent the SGPs from over-extending past the PGCs. Our findings provide a foundation for understanding the cellular and molecular regulation of the establishment of a niche-stem cell relationship. PMID:23562590

Rohrschneider, Monica R; Nance, Jeremy

2013-07-15

202

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

PubMed Central

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

Zheng, Qiaolin; Perry, Sharyn E.

2014-01-01

203

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

PubMed

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

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

2010-07-01

204

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

PubMed

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

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

2007-08-01

205

Spruce embryogenesis.  

PubMed

Somatic embryogenesis, the process in which embryos, similar in morphology to their zygotic counterparts, are induced to develop in culture from somatic cells, is a suitable model system for investigating the regulation of embryo development. Through this process, a large number of embryos at defined stages of development can easily be obtained. Somatic embryogenesis in Norway spruce is comprised of a sequence of steps including initiation, proliferation, early embryo formation, embryo maturation, desiccation and germination. To execute this pathway, a number of critical physical and chemical treatments should be applied with proper timing. Embryogenic cell lines of Norway spruce are initiated from zygotic embryos. The cell lines proliferate as proembryogenic masses (PEMs) in the presence of auxin and cytokinin. Early somatic embryos develop from PEMs after withdrawal of auxin and cytokinin. PEM to somatic embryo transition is a key developmental switch that determines the yield and quality of mature somatic embryos. The embryos develop further, to a stage corresponding to late embryogeny, in the presence of abscisic acid. Some cell lines deviate from normal pattern formation exhibiting developmental arrest at certain stages. These arrested cell lines, together with transgenic lines, are valuable tools for studying embryo development. Particle bombardment is routinely used to produce transgenic plants of Norway spruce. PMID:18369995

von Arnold, Sara; Clapham, David

2008-01-01

206

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

PubMed Central

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

Chen, Jen-Tsung

2014-01-01

207

A novel in vitro protocol for inducing direct somatic embryogenesis in Phalaenopsis aphrodite without taking explants.  

PubMed

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

Feng, Jia-Hua; Chen, Jen-Tsung

2014-01-01

208

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

209

Somatic Embryogenesis in Larix  

Microsoft Academic Search

\\u000a The genus Larix has 10 species and many varieties and hybrids. They are native in the cool-temperate and boreal regions of the northern hemisphere\\u000a and in the Himalaya mountains (Gower & Richards, 1990). An outstanding characteristic of Larix is that it is the only conifer genus that is deciduous. In part because of their deciduous habit, many larches can endure

Jan M. Bonga; Krystyna Klimaszewska; Marie-Anne Lelu; Patrick Aderkas

210

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

211

Genomewide analysis of small RNAs in nonembryogenic and embryogenic tissues of citrus: microRNA- and siRNA-mediated transcript cleavage involved in somatic embryogenesis.  

PubMed

Somatic embryogenesis (SE) is a process of somatic cells becoming dedifferentiated and generating embryos. SE has been widely used in biotechnology as a powerful way of regeneration and a model system for studying plant embryogenesis, but the controlling mechanisms of SE are far from clear. Here, we show the genomewide profiles of miRNAs/siRNAs and their target genes in nonembryogenic and embryogenic tissues of 'Valencia' sweet orange. By high-throughput sequencing (HTS) of small RNAs and RNA degradome tags, we identified 50 known and 45 novel miRNAs, 130 miniature inverted-repeat transposable elements (MITEs) derived, 94 other and 235 phased small interfering RNAs (siRNAs), as well as 203 target genes. The majority of the abundantly expressed miRNAs/siRNAs exhibit lower expression levels in embryogenic callus (EC) or during SE process than in nonembryogenic callus (NEC), which is supposed to derepress the target genes that are involved in development and stress response, thus to activate the biological processes required for cell differentiation. However, the conserved csi-miR156a/b, miR164b and 171c directed suppression of specific transcription factors (TFs) are supposed to inactivate the postembryonic growth thus to maintain normal SE. In this study, miRNA- and siRNA-mediated silencing of target genes was found under sophisticated regulation in citrus SE system; the enhancement effect of specific conserved miRNAs on SE was discussed, providing new clues for future investigation of mechanisms that control SE. PMID:25615015

Wu, Xiao-Meng; Kou, Shu-Jun; Liu, Yuan-Long; Fang, Yan-Ni; Xu, Qiang; Guo, Wen-Wu

2015-04-01

212

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

213

Comparative analysis reveals dynamic changes in miRNAs and their targets and expression during somatic embryogenesis in longan (Dimocarpus longan Lour.).  

PubMed

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

Lin, Yuling; Lai, Zhongxiong

2013-01-01

214

In vitro pollen embryogenesis in Nicotiana tabacum L. and its relation to pollen sterility, sex balance, and floral induction of the pollen donor plants  

Microsoft Academic Search

Pollen sterility, sex balance, and floral induction of the pollen donor plants were tested for a possible relation to embryogenesis from in vitro cultured tobacco pollen (Nicotiana tabacum L. var. Badischer Burley). The pollen grains destined to become embryos in culture (P-grains) were sterile for the donor plants as judged by their staining reaction with acetocarmine and fluorescin-diacetate, and by

Erwin Heberle-Bors

1982-01-01

215

Sex determination of the Drosophila germ line: tra and dsx control somatic inductive signals.  

PubMed

In Drosophila, the sex of germ cells is determined by cell-autonomous and inductive signals. XY germ cells autonomously enter spermatogenesis when developing in a female host. In contrast, XX germ cells non-autonomously become spermatogenic when developing in a male host. In first instar larvae with two X chromosomes, XX germ cells enter the female or the male pathway depending on the presence or absence of transformer (tra) activity in the surrounding soma. In somatic cells, the product of tra regulates the expression of the gene double sex (dsx) which can form a male-specific or a female-specific product. In dsx mutant larvae, XX and XY germ cells develop abnormally, with a seemingly intersexual phenotype. This indicates that female-specific somatic dsx products feminize XX germ cells, and male-specific somatic dsx products masculinize XX and XY germ cells. The results show that tra and dsx control early inductive signals that determine the sex of XX germ cells and that somatic signals also affect the development of XY germ cells. XX germ cells that develop in pseudomales lacking the sex-determining function of Sxl are spermatogenic. If, however, female-specific tra functions are expressed in these animals, XX germ cells become oogenic. Furthermore, transplanted XX germ cells can become oogenic and form eggs in XY animals that express the female-specific function of tra. Therefore, TRA product present in somatic cells of XY animals or in animals lacking the sex-determining function of Sxl, is sufficient to support developing XX germ cells through oogenesis. PMID:8162863

Steinmann-Zwicky, M

1994-03-01

216

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

PubMed Central

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

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

2014-01-01

217

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

2012-10-01

218

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

PubMed

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

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

1999-03-01

219

Proteomic and histological analyses of endosperm development in Cyclamen persicum as a basis for optimization of somatic embryogenesis.  

PubMed

The endosperm plays an important role for the development of zygotic embryos, while somatic embryos lack a seed coat and endosperm and often show physiological disorders. This study aims at elucidating the cellular and physiological processes within the endosperm of the ornamental species Cyclamen persicum Mill. Histological analyses were performed from 0 to 11 weeks after pollination (WAP). At 3WAP, a syncytium was clearly visible with a globular zygotic embryo. From 4WAP, cellularization of the endosperm, at 5WAP a small torpedo shaped embryo, and from 7WAP cell expansion was observed. By 11WAP the endosperm appeared fully differentiated. Total soluble proteins were extracted from the endosperm at 4, 5, 7, 9 and 11WAP and resolved using two dimensional isoelectric focussing/sodium dodecyl sulphate-polyacrylamide gel electrophoresis (2D IEF/SDS-PAGE). A shift from high-molecular-mass proteins to low-molecular-mass proteins during endosperm development was observed. A total of 1137proteinspots/gel were detected in the three protein fractions extracted at 7, 9 and 11WAP. Mass spectrometry analysis of the 48 predominant protein spots in endosperm at 7, 9 and 11WAP resulted in the identification of 62 proteins, ten of which were described for the first time in Cyclamen. Additionally, 186 proteins were identified using the C. persicum embryo proteome reference map. Proteins involved in abscisic acid signalling and oxidative stress responsive proteins were found to be important for seed development in Cyclamen. The new insights into endosperm physiology including storage compounds are discussed. PMID:23352402

Mwangi, Jenniffer Wamaitha; Rode, Christina; Colditz, Frank; Haase, Christin; Braun, Hans-Peter; Winkelmann, Traud

2013-03-01

220

Somatic aberration induction in Tradescantia occidentalis by neutrons, x- and gamma-radiations. I. Dosimetry.  

PubMed

The dosimetry is described for an investigation of the induction of somatic aberrations in Tradescantia occidentalis by substantially mono-energetic neutrons in the energy range 100 keV to 15 MeV, by 200 keV X-rays and cobalt-60 gamma-radiation. Spectrometry was carried out for both neutrons and X-rays. Neutron fluence was measured by uranium fission chambers. Two types of ionization chamber were employed for dose measurement. One chamber was manufactured of CH-plastic and filled with acetylene and the other of graphite and filled with carbon dioxide. Dosimetry for X- and gamma-radiation was by means of lithium fluoride thermoluminescent dosemeters calibrated against a Victoreen ionization chamber. PMID:1084865

Dennis, J A; Delafield, H J; Peaple, L H; Boot, S J

1976-04-01

221

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

222

Enhancement of American chestnut somatic seedling production  

Microsoft Academic Search

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

G. M. Andrade; S. A. Merkle

2005-01-01

223

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

224

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

225

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

226

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

Microsoft Academic Search

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

M. A. Sigareva; E. D. Earle

1999-01-01

227

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

Microsoft Academic Search

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

Jin-Zhuo Dong; David I. Dunstan

1996-01-01

228

Signal molecules involved in plant embryogenesis  

Microsoft Academic Search

In plant embryogenesis, inductive interactions mediated by diffusable signal molecules are most likely of great importance. Evidence has been presented that at late globular stages in plant embryogenesis, perturbation of the polar auxin transport results in abberrant embryo morphology. Rhizobium lipooligosaccharides or Nod factors are a newly discovered class of bacterial molecules that are able to trigger initial steps in

Ed D. L. Schmidt; Anke J. Jong; Sacco C. Vries

1994-01-01

229

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

PubMed Central

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

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

2002-01-01

230

Redox state of low-molecular-weight thiols and disulphides during somatic embryogenesis of salt-treated suspension cultures of Dactylis glomerata L.  

PubMed

The tripeptide antioxidant ?-L-glutamyl-L-cysteinyl-glycine, or glutathione (GSH), serves a central role in ROS scavenging and oxidative signalling. Here, GSH, glutathione disulphide (GSSG), and other low-molecular-weight (LMW) thiols and their corresponding disulphides were studied in embryogenic suspension cultures of Dactylis glomerata L. subjected to moderate (0.085 M NaCl) or severe (0.17 M NaCl) salt stress. Total glutathione (GSH + GSSG) concentrations and redox state were associated with growth and development in control cultures and in moderately salt-stressed cultures and were affected by severe salt stress. The redox state of the cystine (CySS)/2 cysteine (Cys) redox couple was also affected by developmental stage and salt stress. The glutathione half-cell reduction potential (E(GSSG/2 GSH)) increased with the duration of culturing and peaked when somatic embryos were formed, as did the half-cell reduction potential of the CySS/2 Cys redox couple (E(CySS/2 Cys)). The most noticeable relationship between cellular redox state and developmental state was found when all LMW thiols and disulphides present were mathematically combined into a 'thiol-disulphide redox environment' (E(thiol-disulphide)), whereby reducing conditions accompanied proliferation, resulting in the formation of pro-embryogenic masses (PEMs), and oxidizing conditions accompanied differentiation, resulting in the formation of somatic embryos. The comparatively high contribution of E(CySS/2 Cys) to E(thiol-disulphide) in cultures exposed to severe salt stress suggests that Cys and CySS may be important intracellular redox regulators with a potential role in stress signalling. PMID:22348546

Zagorchev, Lyuben; Seal, Charlotte E; Kranner, Ilse; Odjakova, Mariela

2012-05-01

231

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

232

Pine embryogenesis  

PubMed Central

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

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

2009-01-01

233

Detection of a SERK-like gene in coconut and analysis of its expression during the formation of embryogenic callus and somatic embryos.  

PubMed

Somatic embryogenesis involves different molecular events including differential gene expression and various signal transduction pathways. One of the genes identified in early somatic embryogenesis is S OMATIC E MBRYOGENESIS R ECEPTOR-like K INASE (SERK). Cocos nucifera (L.) is one of the most recalcitrant species for in vitro regeneration, achieved so far only through somatic embryogenesis, although just a few embryos could be obtained from a single explant. In order to increase efficiency of this process we need to understand it better. Therefore, the purpose of the present work was to determine if an ortholog of the SERK gene is present in the coconut genome, isolate it and analyze its expression during somatic embryogenesis. The results showed the occurrence of a SERK ortholog referred to as CnSERK. Predicted sequence analysis showed that CnSERK encodes a SERK protein with the domains reported in the SERK proteins in other species. These domains consist of a signal peptide, a leucine zipper domain, five LRR, the Serine-Proline-Proline domain, which is a distinctive domain of the SERK proteins, a single transmembrane domain, the kinase domain with 11 subdomains and the C terminal region. Analysis of its expression showed that it could be detected in embryogenic tissues before embryo development could be observed. In contrast it was not detected or at lower levels in non-embryogenic tissues, thus suggesting that CnSERK expression is associated with induction of somatic embryogenesis and that it could be a potential marker of cells competent to form somatic embryos in coconut tissues cultured in vitro. PMID:18818928

Pérez-Núńez, M T; Souza, R; Sáenz, L; Chan, J L; Zúńiga-Aguilar, J J; Oropeza, C

2009-01-01

234

Technological Overview of iPS Induction from Human Adult Somatic Cells  

PubMed Central

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

Bayart, Emilie; Cohen-Haguenauer, Odile

2013-01-01

235

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

236

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

PubMed Central

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

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

2014-01-01

237

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

Microsoft Academic Search

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

ANNA MIKUčA; AGNIESZKA FIUK; JAN J. RYBCZYNSKI

2005-01-01

238

Cloning of genes developmentally regulated during plant embryogenesis  

PubMed Central

Genes specifically induced during somatic embryogenesis may play key roles in plant embryo development. An antiserum against an extract of carrot somatic embryos revealed a few rare antigens induced at the onset of embryogenesis. Through differential immunoadsorption techniques, we purified antibodies against the embryo-specific antigens and probed a phage ? gt11 library of cDNA from carrot somatic embryos. This paper describes three distinct cDNA clones that hybridize to embryo-specific RNAs. Monospecific antibodies, purified by affinity to the recombinant phage fusion proteins, confirm that the cloned cDNAs encode unique embryo-specific peptide antigens. One 50-kDa protein correlates with embryogenic ability in cultures of other plant species, including cereals. Images PMID:16593822

Choi, Jung H.; Liu, Liang-shi; Borkird, Chumpol; Sung, Z. R.

1987-01-01

239

Enhanced adventive embryogenesis resulting from plasmolysis of cultured wild carrot cells  

Microsoft Academic Search

Adventive embryogenesis in vitro-grown somatic cells of Daucus carota L. was increased three-fold by a 45 min plasmolysis pre-treatment using 1M sucrose solutions. A high degree of synchronous development also resulted from this treatment. The enhancement of embryogenesis is interpreted as an increase in the regeneration of cells which have become physiologically somewhat isolated from the tissue of their origin

D. F. Wetherell

1984-01-01

240

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

241

Induction of differentiation by down-regulation of Nanog and Rex-1 in cord blood derived unrestricted somatic stem cells.  

PubMed

Stem cells with high self-renewal and tissue regeneration potentials are the core components of regenerative medicine. Adult stem cells with many available sources, high repairing ability, and also possessing no ethical issues are popular candidates in the clinical field. In this study we looked upon the effects of two transcription factors Nanog and Rex-1 in self-renewal and differentiation abilities of a subpopulation of cord blood stem cells known as unrestricted somatic stem cells (USSCs). USSCs were expanded and transfected in vitro with siRNAs targeting either Nanog, Rex-1, and in combination. Gene suppressions were achieved at both transcript and proteome level. Differentiations were evaluated by specific Real time PCR and differentiating staining. Nanog knock down revealed a significant increase in osteogenic markers, Osteocalcin and Osteopontin expression as well as a positive Alizarin Red staining, which proposes Osteogenesis. This treatment also became positive for Oil Red staining, implying adipogenic differentiation as well. In contrast, Rex-1 knock down showed an increase in MAP II and Nestin expression, which is a hall mark of neural differentiation. Surprisingly, treatment with both siRNAs did not express any changes in any of the assessed markers. Therefore, our results indicated a bilateral mesenchymal differentiation for Nanog and a neural lineage fate for Rex-1 suppression. Considering that both transcription factors are core activators of self-renewal and also are orchestrating with other factors, our results imply a positive feedback in response to changes in the regulatory network of self-renewal. PMID:23661017

Langroudi, Lida; Forouzandeh, Mehdi; Soleimani, Masoud; Atashi, Amir; Golestaneh, Azadeh Fahim

2013-07-01

242

Dormancy induction of somatic embryos of Siberian ginseng by high sucrose concentrations enhances the conservation of hydrated artificial seeds and dehydration resistance  

Microsoft Academic Search

. In most plants, somatic embryos tend to germinate prematurely, a process that is detrimental to controlled plant production and the conservation of artificial seeds. We investigated the dormancy characteristics of Siberian ginseng somatic embryos induced simply by a high sucrose treatment, a treatment that enables the long-term conservation of artificial seeds following encapsulation and provides embryos with an enhanced

Y. E. Choi; J. H. Jeong

2002-01-01

243

Synthetic seed production from somatic embryos of Pinus radiata  

Microsoft Academic Search

Pinus radiata is one of the most important forestry species in the southern hemisphere. This work describes the regeneration of this plant\\u000a via somatic embryogenesis from immature zygotic embryos. To improve this process, somatic embryogenic cell suspensions were\\u000a established in liquid media for the generation of material for embryo maturation. Each developmental stage of these suspensions\\u000a was characterized by microscopy

Felipe Aquea; María Josefina Poupin; José Tomás Matus; Marlene Gebauer; Consuelo Medina; Patricio Arce-Johnson

2008-01-01

244

Plant regeneration from somatic embryos in black pepper  

Microsoft Academic Search

Embryogenic callus derived from zygotic embryos of black pepper (Piper nigrum Linn.) were induced to form somatic embryos on solid and liquid Schenk and Hildebrandt basal medium. Callus proliferation,\\u000a somatic embryo-genesis and germination of embryos were achieved in about 8 months in static cultures while it took only 8\\u000a weeks in liquid suspension cultures. The highest number of embryos and

Biju Joseph; Dominic Joseph; V. J. Philip

1997-01-01

245

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

246

Intergeneric somatic hybrid plants from sexually incompatible woody species: Citrus sinensis and Severinia disticha  

Microsoft Academic Search

The fusion of Citrus sinensis cv. Hamlin (sweet orange) protoplasts isolated from an embryogenic suspension culture with Severinia disticha (Philippine box orange) protoplasts isolated from epicotyl-derived callus with organogenic potential, resulted in the regeneration of allotetraploid somatic hybrid plants. Plant regeneration was a function of complementation, combining the capacity for somatic embryogenesis of C. sinensis with the organogenic ability of

J. W. Grosser; F. G. Gmitter; J. L. Chandler

1988-01-01

247

[Specific features of early embryogenesis in apomictic Poa pratensis L].  

PubMed

We studied the early stages of embryo formation in apomictic Poa partensis L. It was shown that during transition to parthenogenesis, at least at the initial stages of embryogenesis, the algorithm of development of the sexual embryo is preserved. This could be due to the system of genetic control of embryogenesis, common for amphimixis and apomixis. We described asynchrony of developmental processes both within the efflorescence (asynchronous maturation of ovules) and within the ovule and even gametophyte (different timing of induction of apoarchesporic initials and oospores). This feature of pseudogamous apomicts allows them to produce simultaneously both sexual and apomictic progenies. PMID:17352289

Iudakova, O I; Shakina, T N

2007-01-01

248

Synthetic seed production from somatic embryos of Pinus radiata.  

PubMed

Pinus radiata is one of the most important forestry species in the southern hemisphere. This work describes the regeneration of this plant via somatic embryogenesis from immature zygotic embryos. To improve this process, somatic embryogenic cell suspensions were established in liquid media for the generation of material for embryo maturation. Each developmental stage of these suspensions was characterized by microscopy and their growth phases quantified. An alginate-containing medium was used as an encapsulation method for the somatic embryos that were then germinated as artificial seeds in vitro. The protocols described in this work are both useful and reliable for industrial purposes. PMID:18563583

Aquea, Felipe; Poupin, María Josefina; Matus, José Tomás; Gebauer, Marlene; Medina, Consuelo; Arce-Johnson, Patricio

2008-10-01

249

THE REGENERATION OF BLACK GRAMA PLANTS VIA SOMATIC EMBRYOGENESIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

250

Alfalfa heat shock genes are differentially expressed during somatic embryogenesis  

Microsoft Academic Search

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

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

1991-01-01

251

Primary and cyclic somatic embryogenesis in cassava (Manihot esculente Crantz)  

Microsoft Academic Search

Cassava is one of the major food crops in the tropics. Several of the major problems in cassava can probably only be solved by breeding with cellular and molecular techniques, e.g., the introduction of specific genes (virus resistance, protein content, quality aspects and so on). These genes can be directly applied in existing varieties of vegetatively propagated crops like cassava.

C. J. J. M. Raemakers

1993-01-01

252

Somatic embryogenesis from immature inflorescences of oil palm  

Microsoft Academic Search

Summary  Immature inflorescences of oil palm (Elaeis guineensis) var. Pisifera were inoculated onto modified MS medium containing 0.3% (w\\/v) activated charcoal and 475 M 2,4-D. After 2—3 months of culture, a hard yellow callus proliferated at the base of the shoot-like structures. The high incidence of phenolic oxidation required the use of increased levels of activated charcoal (0.5% w\\/v) and 2,4-D

J. B. Teixeira; M. R. Söndahl; E. G. Kirby

1994-01-01

253

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

254

Regulation of somatic embryogenesis by plant growth regulators in sugarcane  

Microsoft Academic Search

Effect of plant growth regulators on morphogenesis was studied using callus derived from inflorescence segments of sugarcane\\u000a cv. Co-91010 and CoC-671 cultured on MS medium supplemented with 2,4-D, malt extract, L-glutamine, casein hydroly sate and\\u000a coconut water (CW). Comparison was made of different media combinations of CW (5,10%), kinetin (lmg\\/l), zeatin (0.5mg\\/l) andTDZ\\u000a (0.5mg\\/l) to study callus growth and regeneration.

P. Suprasanna; R. S. Choudhary; N. S. Desai; V. A. Bapat

2005-01-01

255

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

PubMed Central

Background Microspore embryogenesis represents a unique system of single cell reprogramming in plants wherein a highly specialized cell, the microspore, by specific stress treatment, switches its fate towards an embryogenesis pathway. In Brassica napus, a model species for this phenomenon, incubation of isolated microspores at 32°C is considered to be a pre-requisite for embryogenesis induction. Results We have developed a new in vitro system at lower temperature (18°C) to efficiently induce microspore embryogenesis throughout two different developmental pathways: one involving the formation of suspensor-like structures (52.4%) and another producing multicellular embryos without suspensor (13.1%); additionally, a small proportion of non-responsive microspores followed a gametophytic-like development (34.4%) leading to mature pollen. The suspensor-like pathway followed at 18°C involved the establishment of asymmetric identities from the first microspore division and an early polarity leading to different cell fates, suspensor and embryo development, which were formed by cells with different organizations and endogenous auxin distribution, similar to zygotic embryogenesis. In addition, a new strategy for germination of microspore derived embryos was developed for achieving more than 90% conversion of embryos to plantlets, with a predominance of spontaneous doubled haploids plants. Conclusion The present work reveals a novel mechanism for efficient microspore embryogenesis induction in B. napus using continuous low temperature treatment. Results indicated that low temperature applied for longer periods favours an embryogenesis pathway whose first division originates asymmetric cell identities, early polarity establishment and the formation of suspensor-like structures, mimicking zygotic embryogenesis. This new in vitro system provides a convenient tool to analyze in situ the mechanisms underlying different developmental pathways during the microspore reprogramming, breaking or not the cellular symmetry, the establishment of polarity and the developmental embryo patterning, which further produce mature embryos and plants. PMID:22857779

2012-01-01

256

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

PubMed

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

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

2014-11-01

257

Pollen embryogenesis: atavism or totipotency?  

Microsoft Academic Search

Summary The origins of pollen embryogenesis are still in doubt. Totipotency of plant cells has traditionally been put forward as an explanation for this phenomenon but we have found this interpretation to involve some shortcomings. The pollen grain is a highly differentiated structure which should have a very reduced capability of regenerating a whole plant, whereas in some species the

F. J. Bonet; L. Azbaid; A. Olmedilla

1998-01-01

258

[Depression and somatic comorbidity].  

PubMed

Depressed persons have a higher risk of developing somatic conditions such as cardiovascular disease, diabetes and obesity. Somatic comorbidity in depressed persons may be explained by mediating mechanisms such as unhealthy lifestyle and unfavorable pathophysiological disturbances. There are alternative explanations for somatic comorbidity in depressed persons: genetic pleiotropy, iatrogenic effects, and the phenomenon 'somatic depression'. In the latter, the symptoms of depression are a consequence of clinical or subclinical somatic conditions. When treating a depressed patient, their somatic health should also be monitored. Further research is needed to examine whether specific interventions may prevent somatic comorbidity in depression. PMID:20456788

Penninx, Brenda W J H; van Dyck, Richard

2010-01-01

259

In vitro response of encapsulated somatic embryos of camellia  

Microsoft Academic Search

Somatic embryos of Camellia japonica were hydrogel encapsulated using 3% sodium alginate and 0.1 M calcium chloride to produce\\u000a synthetic seeds. Both germinability and repetitive embryogenesis capacity of the encapsulated embryos were investigated. The\\u000a frequency of in vitro germination into plants of artificial seeds was affected by various nutrient additives included in the\\u000a encapsulating matrix. The addition of Ca-free Murashige

Laura V. Janeiro; Antonio Ballester; Ana M. Vieitez

1997-01-01

260

Histology of Organogenic and Embryogenic Responses in Cotyledons of Somatic Embryos of Quercus suber L  

Microsoft Academic Search

In cork oak (Quercus suber L.), recurrent embryogenesis is produced in vitro through autoembryony without exogenous plant growth regulators (PGRs); secondary embryos appear on the embryo axis but seldom on cotyledons. Focusing mainly on the histological origin of neoformations, we investigated the influence of the embryo axis and exogenous PGRs on the embryogenic potential of somatic embryo cotyledons. Isolated cotyledons

Pere Puigderrajols; Cristina Celestino; Monica Suils; Mariano Toribio; Marisa Molinas

2000-01-01

261

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...

262

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

Microsoft Academic Search

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

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

1993-01-01

263

Refining the application of direct embryogenesis in sugarcane: effect of the developmental phase of leaf disc explants and the timing of DNA transfer on transformation efficiency  

Microsoft Academic Search

A rapid in vitro protocol using direct somatic embryogenesis and microprojectile bombardment was investigated to establish the developmental phases most suitable for efficient sugarcane transformation. Immature leaf roll disc explants with and without pre-emergent inflorescence tissue were compared. It was shown that for effective transformation to occur, explants should be cultured for several days to allow initiation of embryo development

S. J. Snyman; G. M. Meyer; J. M. Richards; N. Haricharan; S. Ramgareeb; B. I. Huckett

2006-01-01

264

The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos.  

PubMed

Somatic embryogenesis (SE) represents a useful experimental system for studying the regulatory mechanisms of embryo development. In this study, the effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce [Picea abies (L.) Karst] somatic embryos were investigated. Using time lapse photography, we monitored development from proliferation of proembryogenic masses (PEMs) to maturation of somatic embryos in two P. abies cell lines cultured on two maturation treatments. A combination of sugar assays, metabolic and proteomic analyses were used to quantify storage reserves in the mature somatic embryos. The maturation treatment containing a nonpermeating osmoticum, polyethylene glycol (PEG, 7.5%) and maltose (3%) as the carbohydrate gave significantly high maturation and low germination frequencies of somatic embryos compared to the treatment with only 3% sucrose. Somatic embryos treated with 3% sucrose contained high levels of sucrose, raffinose and late embryogenesis abundant (LEA) proteins. These compounds are known to be involved in the acquisition of desiccation tolerance during seed development and maturation. In addition the sucrose treatment significantly increased the content of starch in the somatic embryos while the maltose and PEG treatment resulted in somatic embryos with a high content of storage proteins. The high levels of sucrose, raffinose and LEA proteins in the embryos treated with 3% sucrose suggest that sucrose may improve the germination of somatic embryos by promoting the acquisition of desiccation tolerance. PMID:23421376

Businge, Edward; Bygdell, Joakim; Wingsle, Gunnar; Moritz, Thomas; Egertsdotter, Ulrika

2013-10-01

265

Somatic mosaicism and disease.  

PubMed

The large number of cell divisions required to make a human body inevitably leads to the accumulation of somatic mutations. Such mutations cause individuals to be somatic mosaics. Recent advances in genomic technology now allow measurement of somatic diversity. Initial studies confirmed the expected high levels of somatic mutations within individuals. Going forward, the big questions concern the degree to which those somatic mutations influence disease. Theory predicts that the frequency of mutant cells should vary greatly between individuals. Such somatic mutational variability between individuals could explain much of the diversity in the risk of disease. But how variable is mosaicism between individuals in reality? What is the relation between the fraction of cells carrying a predisposing mutation and the risk of disease? What kinds of heritable somatic change lead to disease besides classical DNA mutations? What molecular processes connect a predisposing somatic change to disease? We know that predisposing somatic mutations strongly influence the onset of cancer. Likewise, neurodegenerative diseases may often begin from somatically mutated cells. If so, both neurodegeneration and cancer may be diseases of later life for which much of the risk may be set by early life somatic mutations. PMID:24937287

Frank, Steven A

2014-06-16

266

Preliminary research on conversion of encapsulated somatic embryos of Citrus reticulata Blanco, cv. Mandarino Tardivo di Ciaculli  

Microsoft Academic Search

Somatic embryogenesis was obtained through anther culture of Citrus reticulata, cv. Mandarino Tardivo di Ciaculli. The work was carried out to evaluate the response of somatic embryos inside a sodium\\u000a alginate coating to different storage periods, and to the effects of the germicide PPM (1 ml l?1) and the fungicide Thiophanate-methyl (100 mg l?1). The effect of these alone or in combination, added to

Germanŕ Maria Antonietta; Hafiz Ishfaq Ahmad; Micheli Maurizio; Standardi Alvaro

2007-01-01

267

Somatic embryo culture for propagation, artificial seed production, and conservation of sawara cypress ( Chamaecyparis pisifera Sieb. et Zucc.)  

Microsoft Academic Search

Somatic embryogenesis in Chamaecyparis pisifera Sieb. et Zucc. was initiated from immature seeds collected from the end of June to early July. Mass propagation through adventitious\\u000a shoot bud production from somatic embryo culture on Woody Plant (WP) medium and artificial seed production using sodium alginate\\u000a was achieved. A high bud forming index value (25.8) was obtained on medium supplemented with

Emilio Maruyama; Yoshihisa Hosoi; Katsuaki Ishii

2003-01-01

268

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

PubMed Central

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

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

2014-01-01

269

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

PubMed

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

Lopes, Tina; Pinto, Glória; Loureiro, Joăo; Costa, Armando; Santos, Conceiçăo

2006-09-01

270

Somatization in the community.  

PubMed

We examined the prevalence of somatization disorder symptoms elicited with the Diagnostic Interview Schedule in 3132 community respondents interviewed in Los Angeles by the Epidemiologic Catchment Area program. The variables age, gender, ethnic background, and the presence of a psychiatric diagnosis significantly influenced the number of somatization symptoms reported. An introductory review on conceptual and nosological aspects of somatization phenomena led to the formulation of a less-restrictive operational definition of the somatizer. We found that 4.4% of the respondents met criteria for this abridged cutoff score of somatization, whereas only 0.03% of the respondents met criteria for the full DSM-III somatization disorder diagnosis. This abridged cutoff score was associated with sociodemographic factors and psychiatric diagnosis in the direction predicted. PMID:3498454

Escobar, J I; Burnam, M A; Karno, M; Forsythe, A; Golding, J M

1987-08-01

271

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

PubMed

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

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

2014-09-17

272

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

273

Somatization, Paranoia, and Language.  

ERIC Educational Resources Information Center

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

Oxman, Thomas E.; And Others

1988-01-01

274

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’). PMID:17384168

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

2007-01-01

275

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

PubMed

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

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

1989-11-01

276

Locus-Specific DNA Methylation Reprogramming During Early Porcine Embryogenesis1  

PubMed Central

ABSTRACT During early mammalian embryogenesis, there is a wave of DNA demethylation postfertilization and de novo methylation around implantation. The paternal genome undergoes active DNA demethylation, whereas the maternal genome is passively demethylated after fertilization in most mammals except for sheep and rabbits. However, the emerging genome-wide DNA methylation landscape has revealed a regulatory and locus-specific DNA methylation reprogramming pattern in mammalian preimplantation embryos. Here we optimized a bisulfite sequencing protocol to draw base-resolution DNA methylation profiles of several selected genes in gametes, early embryos, and somatic tissue. We observed locus-specific DNA methylation reprogramming in early porcine embryos. First, some pluripotency genes (POU5F1 and NANOG) followed a typical wave of DNA demethylation and remethylation, whereas CpG-rich regions of SOX2 and CDX2 loci were hypomethylated throughout development. Second, a differentially methylated region of an imprint control region in the IGF2/H19 locus exhibited differential DNA methylation which was maintained in porcine early embryos. Third, a centromeric repeat element retained a moderate DNA methylation level in gametes, early embryos, and somatic tissue. The diverse DNA methylation reprogramming during early embryogenesis is thought to be possibly associated with the multiple functions of DNA methylation in transcriptional regulation, genome stability and genomic imprinting. The latest technology such as oxidative bisulfite sequencing to identify 5-hydroxymethylcytosine will further clarify the DNA methylation reprogramming during porcine embryonic development. PMID:23303676

Zhao, Ming-Tao; Rivera, Rocio M.; Prather, Randall S.

2013-01-01

277

Somatization or psychosomatic symptoms?  

PubMed

The author describes some problems emerging from the approach to and comprehension of somatization symptoms, discussing ambiguities regarding somatization seen in the current classification manuals (ICD-10 and DSM-IV). Then the author presents a case report of a man who presented with a bizarre symptom of feminization that was successfully treated with psychotherapy. The author ends with a discussion of the relationship between meaning and symptom. PMID:16508030

Avila, Lazslo Antonio

2006-01-01

278

Defined nuclear changes accompany the reprogramming of the microspore to embryogenesis.  

PubMed

The switch of the gametophytic developmental program toward pollen embryogenesis to form a haploid plant represents an important alternative for plant breeding. In the present study, the switch of the gametophytic developmental program toward a sporophytic pathway, "embryogenesis," has been studied in three different plant species, Brassica, tobacco, and pepper. The switch has been induced by stress (heat shock) at the very responsive stage of the microspore, which is the vacuolate period. As a result, the cell nucleus undergoes striking structural changes with regard to late gametophytic development, including alterations of biosynthetic activities and proliferative activity. An enrichment in HSP70 heat-shock protein and in the presence of Ntf6-MAP kinase was observed after inductive treatment in the nuclei during early embryogenesis. This apparently reflected the possible roles of these proteins, specifically the protective role of HSP70 for the nuclear machinery, and signal transduction of Ntf6-MAPK for the entry of cells into proliferation. Importantly, the observed nuclear changes were similar in the three species investigated and represented convenient markers for early monitoring of embryogenesis and selection purposes for obtaining double-haploid plants in plant breeding. PMID:10806072

Testillano, P S; Coronado, M J; Seguí, J M; Domenech, J; González-Melendi, P; Raska, I; Risueńo, M C

2000-04-01

279

Ethylene precursors and antagonists increase embryogenesis of Hordeum vulgare L. anther culture.  

PubMed

The role of ethylene in microspore embryogenesis and regeneration was analyzed by studying the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and the ethylene antagonists silver nitrate and silver thiosulphate on the androgenic response of in vitro cultured anthers of seven genotypes of barley. Incorporation of either ACC or silver salts in the culture medium lead to a significant increase in callus induction for five of the seven genotypes tested. The treatment that increased callus induction depended upon genotype. Only anthers cultured on 1 mg l(-1) silver thiosulphate gave rise to fertile plants in all seven genotypes tested. PMID:24193518

Evans, J M; Batty, N P

1994-09-01

280

Metabolite profiling reveals clear metabolic changes during somatic embryo development of Norway spruce (Picea abies).  

PubMed

Progress on industrial-scale propagation of conifers by somatic embryogenesis has been hampered by the differences in developmental capabilities between cell lines, which are limiting the capture of genetic gains from breeding programs. In this study, we investigated the metabolic events occurring during somatic embryo development in Norway spruce to establish a better understanding of the fundamental metabolic events required for somatic embryo development. Three embryogenic cell lines of Norway spruce (Picea abies (L.) Karst) with different developmental capabilities were studied during somatic embryo development from proliferation of proembryogenic masses to mature somatic embryos. The three different cell lines displayed normal, aberrant and blocked somatic embryo development. Metabolite profiles from four development stages in each of the cell lines were obtained using combined gas chromatography-mass spectrometry. Multivariate discriminant analyses of the metabolic data revealed significant metabolites (P ??? 0.05) for each development stage and transition. The results suggest that endogenous auxin and sugar signaling affects initial stages of somatic embryo development. Furthermore, the results highlight the importance of a timed stress response and the presence of stimulatory metabolites during late stages of embryo development. PMID:22310018

Businge, Edward; Brackmann, Klaus; Moritz, Thomas; Egertsdotter, Ulrika

2012-02-01

281

Using SomaticSniper to Detect Somatic Single Nucleotide Variants  

PubMed Central

Detecting somatic single nucleotide variants (SNVs) is an essential component of cancer research with next generation sequencing data. This protocol describes how to run the SomaticSniper somatic SNV detector and then filter the output to eliminate most false positives. It also includes support protocols detailing the compilation of the software. PMID:25431635

Larson, David E.; Abbott, Travis E.; Wilson, Richard K.

2014-01-01

282

Somatic mutation theory.  

PubMed

The evidence is reviewed that supports the role of genetic lesions in carcinogenesis; such lesions may be initiating events in the multistep process leading to clinically detectable tumor. Other possible manifestations of alterations in the hereditary material of somatic cells are discussed; DNA damage may lead to benign tumors responsible for atherosclerosis, to neurological deterioration, and to senescence of the individual. During embryonal development, transplacental mutagens may cause somatic mosaicism in the fetus, which may manifest as congenital malformations, spontaneous abortions, and childhood cancers. PMID:7463528

Sorsa, M

1980-01-01

283

Somatic polymorphism and seed dispersal  

Microsoft Academic Search

SOMATIC seed polymorphism is the production of seeds of different morphologies or behaviour on different parts of the same plant and is a somatic differentiation rather than the result of genetic segregation1. This phenomenon appears to be confined to a limited number of families of higher plants (for example, Cruciferae, Compositae, Chenopodiaceae, Gramineae). Seed produced within a somatic polymorphism may

Anne E. Sorensen

1978-01-01

284

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

2012-12-01

285

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

286

Patterns of Gene Expression in Drosophila Embryogenesis  

NSDL National Science Digital Library

A new image database of gene expression patterns in Drosophila embryogenesis is now available from the Berkeley Drosophila Genome Project (BDGP), a consortium of the Drosophila Genome Center. The BDGP team used "high throughput 96-well plate RNA in situ protocol to determine patterns of gene expression during embryogenesis for Drosophila genes represented in non-redundant sets of Drosophila ESTs DGC1 and DGC2." The entire set of image, microarray, and annotation data may be browsed or searched from this Web site. As of October 4, 2002, 1354 gene expressions have been documented with 25,263 digital photographs, with many more additions expected. This site also provides a useful FAQs page.

287

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

288

Periderm prevents pathological epithelial adhesions during embryogenesis  

PubMed Central

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

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

2014-01-01

289

Periderm prevents pathological epithelial adhesions during embryogenesis.  

PubMed

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

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

2014-09-01

290

Mutual inductance Mutual induction  

E-print Network

Mutual inductance Mutual induction ­ current in one coil induces emf in other coil Distinguish from self-induction Mutual inductance, M21 of coil 2 with respect to coil 1 is 1 212 21 i N M = i N L B = #12;Mutual inductance Rearrange equation Vary i1 with time Faraday's law Induced emf in coil 2 due

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

291

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

PubMed

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

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

2009-04-13

292

Arabinogalactan proteins are essential in somatic embryogenesis of Daucus carota L  

Microsoft Academic Search

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

Marc Kreuger; Gerrit-Jan van Hoist

1993-01-01

293

Characterization of a gene that is expressed early in somatic embryogenesis of Daucus carota  

Microsoft Academic Search

lhe EMB-1 mRNA of carrot (Daucus carota) was isolated as an embryo abundant cDNA clone (T.H. Ulrich, E.S. Wurtele, B.J. Nikolau (1990) Nucleic Acids Res 18: 2826). Northern analyses of RNA isolated from embryos, cultured cells, and a variety of vege- tative organs indicate that the EMB-1 mRNA specifically accumu- lates in embryos, beginning at the early stages of embryo

Eve Syrkin Wurtele; Huiqing Wang; SaDly Durgerian; Basil J. Nikolau; Thomas H. Ulrich

1993-01-01

294

Arabinogalactan-protein epitopes in somatic embryogenesis of Daucus carota L  

Microsoft Academic Search

Two monoclonal antibodies (ZUM 15 and ZUM 18) directed against carrot (Daucus carota L.) seed arabinogalactan proteins (AGPs) were used to isolate specific AGP fractions. For both carrot and tomato (Lycopersicon esculentum Mill.) seed AGPs analyzed by crossedelectrophoresis, the ZUM 15 and ZUM 18 AGP fractions showed one identical peak. However, the Rf values for the two species were different:

Marc Kreuger; Gerrit-Jan van Hoist

1995-01-01

295

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

296

Somatic embryogenesis and plant regeneration from immature zygotic embryos of Japanese larch (Larix leptolepis)  

Microsoft Academic Search

Embryogenic tissue was initiated using LM, LP and MS media from open-pollinated immature embryos of Larix leptolepis. The\\u000a initiation frequency varied with collection dates. The highest frequencies of embryogenic tissue initiation (60, 67 and 59%\\u000a on LM, LP and MS media, respectively) were observed from cones collected on July 30. At this time, all the excised embryos\\u000a were at the

Yong Wook Kim; Yang Youn; Eu Rae Noh; Joon Chul Kim

1998-01-01

297

Plant regeneration via somatic embryogenesis from protoplasts of six plant species related to Citrus  

Microsoft Academic Search

Protoplasts isolated from embryogenic callus of Fortunella polyandra (Ridl.), Atalantia bilocularis (Pieree ex Guill.), Hesperethusa crenulata (Roxb.), Glycosmis pentaphylla (Retz.) Corr., Triphasia trifolia (Burm. f.) P. Wils. and Murraya koenigii (L.) Spreng. were cultured in MT (Murashige and Tucker 1969) basal medium containing 5% sucrose supplemented with 0.0, 0.001, 0.01, 0.1 or 1.0 mg l-1 BA and 0.6 M sorbitol.

Hasan Basri Jumin; Nobumasa Nito

1996-01-01

298

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

E-print Network

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

Paris-Sud XI, Université de

299

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

300

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

301

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

302

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

Microsoft Academic Search

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

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

303

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

Microsoft Academic Search

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

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

1997-01-01

304

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

PubMed

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

Gugsa, Likyelesh; Kumlehn, Jochen

2011-01-01

305

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

2006-01-15

306

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

PubMed Central

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

2014-01-01

307

Genetic Regulatory Networks in Embryogenesis and Evolution  

NASA Technical Reports Server (NTRS)

The article introduces a series of papers that were originally presented at a workshop titled Genetic Regulatory Network in Embryogenesis and Evaluation. Contents include the following: evolution of cleavage programs in relationship to axial specification and body plan evolution, changes in cell lineage specification elucidate evolutionary relations in spiralia, axial patterning in the leech: developmental mechanisms and evolutionary implications, hox genes in arthropod development and evolution, heterochronic genes in development and evolution, a common theme for LIM homeobox gene function across phylogeny, and mechanisms of specification in ascidian embryos.

1998-01-01

308

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.

309

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)

2011-11-21

310

Somatic complaints in frontotemporal dementia.  

PubMed

Frontotemporal dementia (FTD) is associated with a broad spectrum of clinical characteristics. The objective of this study was to analyze the prevalence of unexplained somatic complaints in neuropathologically verified FTD. We also examined whether the somatic presentations correlated with protein pathology or regional brain pathology and if the patients with these somatic features showed more depressive traits. Ninety-seven consecutively neuropathologically verified FTLD patients were selected. All 97 patients were part of a longitudinal study of FTD and all medical records were systematically reviewed. The somatic complaints focused on were headache, musculoskeletal, gastro/urogenital and abnormal pain response. Symptoms of somatic character (either somatic complaints and/or abnormal pain response) were found in 40.2%. These patients did not differ from the total group with regard to gender, age at onset or duration. Six patients showed exaggerated reactions to sensory stimuli, whereas three patients showed reduced response to pain. Depressive traits were present in 38% and did not correlate with somatic complaints. Suicidal behavior was present in 17 patients, in 10 of these suicidal behavior was concurrent with somatic complaints. No clear correlation between somatic complaints and brain protein pathology, regional pathology or asymmetric hemispherical atrophy was found. Our results show that many FTD patients suffer from unexplained somatic complaints before and/or during dementia where no clear correlation can be found with protein pathology or regional degeneration. Somatic complaints are not covered by current diagnostic criteria for FTD, but need to be considered in diagnostics and care. The need for prospective studies with neuropathological follow up must be stressed as these phenomena remain unexplained, misinterpreted, bizarre and, in many cases, excruciating. PMID:25232513

Landqvist Waldö, Maria; Santillo, Alexander Frizell; Gustafson, Lars; Englund, Elisabet; Passant, Ulla

2014-01-01

311

Somatic complaints in frontotemporal dementia  

PubMed Central

Frontotemporal dementia (FTD) is associated with a broad spectrum of clinical characteristics. The objective of this study was to analyze the prevalence of unexplained somatic complaints in neuropathologically verified FTD. We also examined whether the somatic presentations correlated with protein pathology or regional brain pathology and if the patients with these somatic features showed more depressive traits. Ninety-seven consecutively neuropathologically verified FTLD patients were selected. All 97 patients were part of a longitudinal study of FTD and all medical records were systematically reviewed. The somatic complaints focused on were headache, musculoskeletal, gastro/urogenital and abnormal pain response. Symptoms of somatic character (either somatic complaints and/or abnormal pain response) were found in 40.2%. These patients did not differ from the total group with regard to gender, age at onset or duration. Six patients showed exaggerated reactions to sensory stimuli, whereas three patients showed reduced response to pain. Depressive traits were present in 38% and did not correlate with somatic complaints. Suicidal behavior was present in 17 patients, in 10 of these suicidal behavior was concurrent with somatic complaints. No clear correlation between somatic complaints and brain protein pathology, regional pathology or asymmetric hemispherical atrophy was found. Our results show that many FTD patients suffer from unexplained somatic complaints before and/or during dementia where no clear correlation can be found with protein pathology or regional degeneration. Somatic complaints are not covered by current diagnostic criteria for FTD, but need to be considered in diagnostics and care. The need for prospective studies with neuropathological follow up must be stressed as these phenomena remain unexplained, misinterpreted, bizarre and, in many cases, excruciating. PMID:25232513

Landqvist Waldö, Maria; Santillo, Alexander Frizell; Gustafson, Lars; Englund, Elisabet; Passant, Ulla

2014-01-01

312

Histology of Organogenic and Embryogenic Responses in Cotyledons of Somatic Embryos of Quercus Suber L.  

PubMed

In cork oak (Quercus suber L.), recurrent embryogenesis is produced in vitro through autoembryony without exogenous plant growth regulators (PGRs); secondary embryos appear on the embryo axis but seldom on cotyledons. Focusing mainly on the histological origin of neoformations, we investigated the influence of the embryo axis and exogenous PGRs on the embryogenic potential of somatic embryo cotyledons. Isolated cotyledons of somatic embryos became necrotic when cultured on PGR-free medium but gave secondary embryos when cultured on media containing benzyladenine and naphthaleneacetic acid. Cotyledons of cork oak somatic embryos are competent to give embryogenic responses. Isolated cotyledons without a petiole showed a lower percentage of embryogenic response than did those with a petiole. In petioles, somatic embryos arose from inner parenchyma tissues following a multicellular budding pattern. Joined to the embryo axis, cotyledons did not show morphogenic responses when cultured on PGR-free medium but revealed budlike and phylloid formations when cultured on medium with PGRs. The different morphogenic behavior displayed by somatic cotyledons indicates an influence of the embryo axis and indicates a relationship between organogenic and embryogenic regeneration pathways. PMID:10817970

Puigderrajols; Celestino; Suils; Toribio; Molinas

2000-05-01

313

Embryogenesis: Pattern Formation from a Single Cell  

PubMed Central

During embryogenesis a single cell gives rise to a functional multicellular organism. In higher plants, as in many other multicellular systems, essential architectural features, such as body axes and major tissue layers are established early in embryogenesis and serve as a positional framework for subsequent pattern elaboration. In Arabidopsis, the apicalbasal axis and the radial pattern of tissues wrapped around it are already recognizable in young embryos of only about a hundred cells in size. This early axial pattern seems to provide a coordinate system for the embryonic initiation of shoot and root. Findings from genetic studies in Arabidopsis are revealing molecular mechanisms underlying the initial establishment of the axial core pattern and its subsequent elaboration into functional shoots and roots. The genetic programs operating in the early embryo organize functional cell patterns rapidly and reproducibly from minimal cell numbers. Understanding their molecular details could therefore greatly expand our ability to generate plant body patterns de novo, with important implications for plant breeding and biotechnology. PMID:22303250

Capron, Arnaud; Chatfield, Steven; Provart, Nicholas; Berleth, Thomas

2009-01-01

314

Hormonal responses during early embryogenesis in maize.  

PubMed

Plant hormones have been shown to regulate key processes during embryogenesis in the model plant Arabidopsis thaliana, but the mechanisms that determine the peculiar embryo pattern formation of monocots are largely unknown. Using the auxin and cytokinin response markers DR5 and TCSv2 (two-component system, cytokinin-responsive promoter version #2), as well as the auxin efflux carrier protein PIN1a (PINFORMED1a), we have studied the hormonal response during early embryogenesis (zygote towards transition stage) in the model and crop plant maize. Compared with the hormonal response in Arabidopsis, we found that detectable hormone activities inside the developing maize embryo appeared much later. Our observations indicate further an important role of auxin, PIN1a and cytokinin in endosperm formation shortly after fertilization. Apparent auxin signals within adaxial endosperm cells and cytokinin responses in the basal endosperm transfer layer as well as chalazal endosperm are characteristic for early seed development in maize. Moreover, auxin signalling in endosperm cells is likely to be involved in exogenous embryo patterning as auxin responses in the endosperm located around the embryo proper correlate with adaxial embryo differentiation and outgrowth. Overall, the comparison between Arabidopsis and maize hormone response and flux suggests intriguing mechanisms in monocots that are used to direct their embryo patterning, which is significantly different from that of eudicots. PMID:24646239

Chen, Junyi; Lausser, Andreas; Dresselhaus, Thomas

2014-04-01

315

Late Embryogenesis Abundant (LEA) proteins in legumes  

PubMed Central

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

Battaglia, Marina; Covarrubias, Alejandra A.

2013-01-01

316

Somatic diversification of antibody responses  

Microsoft Academic Search

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

Biao Zheng; Garnett Kelsoe; Shuhua Han

1996-01-01

317

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

318

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

PubMed

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

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

2004-07-01

319

Somatic embryo-like structures of strawberry regenerated in vitro on media supplemented with 2,4-D and BAP.  

PubMed

Somatic embryo-like structures (SELS) were produced in vitro from leaf disk and petiole explants of two cultivars of strawberry (Fragaria x ananassa Duch) on Murashige and Skoog medium with different concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and sucrose to check the embryonic nature of these structures histologically. A large number of SELS could be regenerated in both cultivars on media with 2-4 mg L(-1) 2,4-D in combination with 0.5 -1 mg L(-1) BAP and 50 g x L(-1) sucrose. Histological examination of SELS revealed the absence of a root pole. Therefore these structures cannot be strictly classified as somatic embryos. The SELS formed under the tested culture conditions represent malformed shoot-like and leaf-like structures. The importance of these results for the propagation of strawberries via somatic embryogenesis is discussed. PMID:24377134

Omar, Genesia F; Mohamed, Fouad H; Haensch, Klaus-Thomas; Sarg, Sawsan H; Morsey, Mohamed M

2013-09-01

320

Temperature manipulation during layer chick embryogenesis.  

PubMed

The current study investigated the effects of temperature manipulation (TM) during late embryogenesis on temperature preference, response to high environmental temperature, behavior, and performance in young layer chicks. Control (CC) embryos (n = 96) were incubated at 37.8 degrees C eggshell temperature throughout incubation. Thermally manipulated embryos (n = 96) were incubated at 37.8 degrees C eggshell temperature throughout incubation and were exposed to 40 degrees C for 4 h/d from embryonic d 14 to 18 (TM chicks). After hatch, chicks from each treatment were divided into 3 subgroups (n = 32 per group) and were subjected to a temperature preference test at d 1, 7, or 33. One day after the temperature preference test, each subgroup was exposed to 1 thermal challenge for 4 h (d 2, 40 degrees C; d 8, 40 degrees C; or d 34, 35 degrees C). Effects of TM on (fearfulness) behavior of chicks were investigated in a tonic immobility test and during home pen observations. Temperature manipulation decreased incubation time with 7 h (P < 0.0001) and body temperature at hatch with 0.2 degrees C (P = 0.002). The TM chicks preferred a lower ambient temperature in the temperature preference test (P < 0.05) and showed a higher body temperature response than CC chicks to the thermal challenge at d 2 and 8 (P < 0.05). No effects of TM on behavior and performance were observed. Because most TM studies are conducted in broilers, this study is the first attempt to unravel the effects of TM during late embryogenesis on posthatch environmental adaptation in layer chicks. The results demonstrated that effects of our TM on postnatal temperature preference and response to high environmental temperatures are only found until d 8 of age. This may suggest 1 of 3 options: a) the timing or the level, or both, of TM and duration were not at the sensitive period of embryogenesis or not sufficient, or both, respectively; b) the level of the postnatal thermal challenge was not strong enough to induce a hyperthermic response; and c) the postnatal effects of TM in layers are limited in time. PMID:20548079

Walstra, I; Ten Napel, J; Kemp, B; van den Brand, H

2010-07-01

321

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

Embryogenic suspensions that involve extensive cell division are risky in respect to genome and epigenome instability. Elevated frequencies of somaclonal variation in embryogenic suspension-derived plants were reported in many species, including coffee. This problem could be overcome by using culture conditions that allow moderate cell proliferation. In view of true-to-type large-scale propagation of C. arabica hybrids, suspension protocols based on low 2,4-D concentrations and short proliferation periods were developed. As mechanisms leading to somaclonal variation are often complex, the phenotypic, genetic and epigenetic changes were jointly assessed so as to accurately evaluate the conformity of suspension-derived plants. The effects of embryogenic suspensions and secondary embryogenesis, used as proliferation systems, on the genetic conformity of somatic embryogenesis-derived plants (emblings) were assessed in two hybrids. When applied over a 6 month period, both systems ensured very low somaclonal variation rates, as observed through massive phenotypic observations in field plots (0.74% from 200,000 plant). Molecular AFLP and MSAP analyses performed on 145 three year-old emblings showed that polymorphism between mother plants and emblings was extremely low, i.e. ranges of 0-0.003% and 0.07-0.18% respectively, with no significant difference between the proliferation systems for the two hybrids. No embling was found to cumulate more than three methylation polymorphisms. No relation was established between the variant phenotype (27 variants studied) and a particular MSAP pattern. Chromosome counting showed that 7 of the 11 variant emblings analyzed were characterized by the loss of 1-3 chromosomes. This work showed that both embryogenic suspensions and secondary embryogenesis are reliable for true-to-type propagation of elite material. Molecular analyses revealed that genetic and epigenetic alterations are particularly limited during coffee somatic embryogenesis. The main change in most of the rare phenotypic variants was aneuploidy, indicating that mitotic aberrations play a major role in somaclonal variation in coffee. PMID:23418563

Bobadilla Landey, Roberto; Cenci, Alberto; Georget, Frédéric; Bertrand, Benoît; Camayo, Gloria; Dechamp, Eveline; Herrera, Juan Carlos; Santoni, Sylvain; Lashermes, Philippe; Simpson, June; Etienne, Hervé

2013-01-01

322

[Hairy root induction and plant regeneration of crownvetch (Coronilla varia L.) transformed by Agrobacterium rhizogenes].  

PubMed

An efficient system of genetic transformation and plant regeneration via somatic embryogenesis was established in crownvetch (Coronilla varia L.) by infecting the segments of cotyledons and hypocotyls of 15d-old seedlings with Agrobacterium rhizogenes strain 15834. Hairy roots were produced directly from the wounded surface of the explants or via calluses on hormone-free Murashige and Skoog (MS) medium after infection by A. rhizogenes. Transformed roots grew rapidly either on solid or liquid MS medium, and exhibited typical hairy root phenotypes. The highest transformation frequency (87.4%) was achieved by preculturing cotyledons for 2d and pre-treating the A. rhizogenes with suitable concentration of acetosyringone at logarithmic phase (OD600 = 0.8). The embryogenic calluses with 100% induction frequency were induced from hairy roots on MS medium containing 0.2mg/L 2,4-D, 0.5mg/L NAA and 0.5mg/L KT. Globular-, heart-, torpedo-, and cotyledon shaped somatic embryos were produced orderly and developed into plantlets when transferred the embryogenic calluses on MS medium supplemented with 0.5mg/L KT, 0.2mg/L IBA and 300mg/L proline. The transformed plants did not show differences in morphology except abundant lateral root branches compared to the non-transformed plants. However, the contents of 3-nitropropanic acid in hairy roots and leaves of one of 5 transformed clones were 57.68% and 58.17% in roots and leaves of untransformed plants, respectively. Opine paper electrophoresis revealed the integration and expression of TR-DNA. PCR analysis confirmed that the TL-DNA including 654 bp rol B sequence was inserted into the genome of transformed hairy roots and their regenerated plants. PMID:16572849

Han, Xiao-Ling; Bu, Huai-Yu; Hao, Jian-Guo; Zhao, Yu-Wei; Jia, Jing-Fen

2006-01-01

323

Bisphenol A induces otolith malformations during vertebrate embryogenesis  

E-print Network

Bisphenol A induces otolith malformations during vertebrate embryogenesis Gibert et al. Gibert et) #12;RESEARCH ARTICLE Open Access Bisphenol A induces otolith malformations during vertebrate Background: The plastic monomer and plasticizer bisphenol A (BPA), used for manufacturing polycarbonate

Paris-Sud XI, Université de

324

Induction of accumulation and degradation of the 18.4-kDa oleosin in a triacylglycerol-storing cell culture of anise ( Pimpinella anisum L.)  

Microsoft Academic Search

Two closely related anise cell-culture lines, Pa15 and Pa19, differ considerably in growth rate, potential to form somatic embryoids, triacylglycerol (TAG) storage and pattern of lipid-body proteins. Line Pa15 grows very fast (doubling rate: 3 d), mainly as single cells, exhibits a low potential for somatic embryogenesis and its TAG content is relatively low (5–20 mg TAG per g dry

Rudolf Radetzky; Ulrike Langheinrich

1994-01-01

325

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

2003-09-01

326

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

327

Somatization and somatic symptom presentation in cancer: a neglected area.  

PubMed

Abstract The recognition of somatization process in cancer patients is a challenging and neglected area, for the extreme difficulty in differentiating and assessing the psycho(patho)logical components from those biologically determined and related to cancer and cancer treatment, as well as for the scarce usefulness of rigid categorical DSM criteria. However, several dimensions of somatization (and the interconnected concept of abnormal illness behaviour) have been shown to be diagnosable in cancer patients and to negatively influence coping and quality of life outcomes. An integration of the formal DSM-ICD nosology with a system specifically taking into account the patients' emotional responses to cancer and cancer treatment, such as the Diagnostic Criteria for Psychosomatic Research (DCPR), is suggested. More data on some specific symptom dimensions, including pain, fatigue and sexual disorders, are needed to examine their possible psychological components. More research is also needed regarding the association of somatization with personality traits (e.g. type D distressed personality, alexithymia), developmental dimensions (e.g. attachment), and cultural issues (e.g. culturally mediated attributional styles to somatic symptoms). Also, the impact and effectiveness of specific therapeutic intervention in 'somatizing' cancer patients is necessary. PMID:23383666

Grassi, Luigi; Caruso, Rosangela; Nanni, Maria Giulia

2013-02-01

328

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

PubMed Central

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

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

1996-01-01

329

Metabolome Analysis of Drosophila melanogaster during Embryogenesis  

PubMed Central

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos’ metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo. PMID:25121768

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

330

Acrolein and embryogenesis: an experimental study  

SciTech Connect

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

Chhibber, G.; Cilani, S.H.

1986-01-01

331

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

332

nAture methods | VOL.10 NO.1 | JANUARY2013 | 77 lineage conversion of one somatic cell type to another is  

E-print Network

amounts. Three approaches for somatic cell reprogramming based on the forced expression of transcrip- tion of mesoder- mal development in different human PSC (hPSC) lines12. We established a mesodermal induction

Cai, Long

333

Drosophila Embryogenesis Scales Uniformly across Temperature in Developmentally Diverse Species  

PubMed Central

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

Kuntz, Steven G.; Eisen, Michael B.

2014-01-01

334

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

335

Pollen embryogenesis to induce, detect, and analyze mutants  

SciTech Connect

The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studies, and the selection of mutations. Although pollen embryogenesis has been demonstrated successfully in numerous plant genera, the procedure cannot as yet be used routinely to generate large populations of plants for experiments. Practical results from use of the technology in genetic toxicology research to detect mutations have failed to fully realize the theoretical potential; further developments of the technology could overcome the limitations. Pollen embryogenesis could be used to develop plants from mutant pollen grains to verify that genetic changes are involved. Through either spontaneous or induced chromosome doubling, these plants can be made homozygous and used to analyze genetically the mutants involved. The success of this approach will depend on the mutant frequency relative to the fraction of pollen grains that undergo embryogenesis; these two factors will dictate population size needed for success. Research effort is needed to further develop pollen embryogenesis for use in the detection of genotoxins under both laboratory and in situ conditions.

Constantin, M.J.

1981-01-01

336

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

PubMed Central

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

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

2008-01-01

337

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. PMID:24138856

Fickentscher, Rolf; Struntz, Philipp; Weiss, Matthias

2013-01-01

338

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

339

Anorexia, coprophagia and somatic outcome  

Microsoft Academic Search

Serious insufficiencies of ego structure and functions may originate from early traumata. The absence or the crushing of fantasies and generally the failure of the symbolic function may be responsible for delusional solutions or for behavioral and somatic outcomes. These ‘solutions’ can be understood as regressions to supposedly inadequate primitive narcissism. The traces and the consequences of the primary traumata

Savvas Savvopoulos

2006-01-01

340

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

341

ERECTA family genes regulate development of cotyledons during embryogenesis.  

PubMed

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

Chen, Ming-Kun; Shpak, Elena D

2014-11-01

342

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

343

Somatic Mutation, Genomic Variation, and Neurological Disease  

PubMed Central

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.

2014-01-01

344

Marker genes identify three somatic cell types in the fetal mouse ovary.  

PubMed

The two main functions of the ovary are the production of oocytes, which allows the continuation of the species, and secretion of female sex hormones, which control many aspects of female development and physiology. Normal development of the ovaries during embryogenesis is critical for their function and the health of the individual in later life. Although the adult ovary has been investigated in great detail, we are only starting to understand the cellular and molecular biology of early ovarian development. Here we show that the adult stem cell marker Lgr5 is expressed in the cortical region of the fetal ovary and this expression is mutually exclusive to FOXL2. Strikingly, a third somatic cell population can be identified, marked by the expression of NR2F2, which is expressed in LGR5- and FOXL2 double-negative ovarian somatic cells. Together, these three marker genes label distinct ovarian somatic cell types. Using lineage tracing in mice, we show that Lgr5-positive cells give rise to adult cortical granulosa cells, which form the follicles of the definitive reserve. Moreover, LGR5 is required for correct timing of germ cell differentiation as evidenced by a delay of entry into meiosis in Lgr5 loss-of-function mutants, demonstrating a key role for LGR5 in the differentiation of pre-granulosa cells, which ensure the differentiation of oogonia, the formation of the definitive follicle reserve, and long-term female fertility. PMID:25158167

Rastetter, Raphael H; Bernard, Pascal; Palmer, James S; Chassot, Anne-Amandine; Chen, Huijun; Western, Patrick S; Ramsay, Robert G; Chaboissier, Marie-Christine; Wilhelm, Dagmar

2014-10-15

345

Intergeneric somatic hybrid plants of Citrus sinensis cv. Hamlin and Poncirus trifoliata cv. Flying Dragon.  

PubMed

Intergeneric somatic hybrid plants between 'Hamlin' sweet orange [Citrus sinensis (L.) Osbeck] and 'Flying Dragon' trifoliate orange (Poncirus trifoliata Raf.) were regenerated following protoplast fusion. 'Hamlin' protoplasts, isolated from an habituated embryogenic suspension culture, were fused chemically with 'Flying Dragon' protoplasts isolated from juvenile leaf tissue. The hybrid selection scheme was based on complementation of the regenerative ability of the 'Hamlin' protoplasts with the subsequent expression of the trifoliate leaf character of 'Flying Dragon.' Hybrid plants were regenerated via somatic embryogenesis and multiplied organogenically. Hybrid morphology was intermediate to that of the parents. Chromosome counts indicated that the hybrids were allotetraploids (2n=4x=36). Malate dehydrogenase (MDH) isozyme patterns confirmed the hybrid nature of the regenerated plants. These genetically unique somatic hybrid plants will be evaluated for citrus rootstock potential. The cell fusion, selection, and regeneration scheme developed herein should provide a general means to expand the germplasm base of cultivated Citrus by intergeneric hybridization with related sexually incompatible genera. PMID:24241403

Grosser, J W; Gmitter, F G; Chandler, J L

1988-01-01

346

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

347

Fetal Alcohol Syndrome: Embryogenesis in a Mouse Model  

Microsoft Academic Search

When two small doses of ethanol were administered to pregnant mice during the gastrulation stage of embryogenesis, the embryos developed craniofacial malformations closely resembling those seen in the human fetal alcohol syndrome. Striking histological changes appeared in the developing brain (neuroectoderm) within 24 hours of exposure. Decreased development of the neural plate and its derivatives apparently accounts for the craniofacial

Kathleen K. Sulik; Malcolm C. Johnston; Mary A. Webb

1981-01-01

348

Optimal Ratio of Transcription Factors for Somatic Cell Reprogramming*  

PubMed Central

Somatic cell reprogramming is achieved by four reprogramming transcription factors (RTFs), Oct3/4, Sox2, Klf4, and c-Myc. However, in addition to the induction of pluripotent cells, these RTFs also generate pseudo-pluripotent cells, which do not show Nanog promoter activity. Therefore, it should be possible to fine-tune the RTFs to produce only fully pluripotent cells. For this study, a tagging system was developed to sort induced pluripotent stem (iPS) cells according to the expression levels of each of the four RTFs. Using this system, the most effective ratio (Oct3/4-high, Sox2-low, Klf4-high, c-Myc-high) of the RTFs was 88 times more efficient at producing iPS cells than the worst effective ratio (Oct3/4-low, Sox2-high, Klf4-low, c-Myc-low). Among the various RTF combinations, Oct3/4-high and Sox2-low produced the most efficient results. To investigate the molecular basis, microarray analysis was performed on iPS cells generated under high (Oct3/4-high and Sox2-low) and low (Oct3/4-low and Sox2-high) efficiency reprogramming conditions. Pathway analysis revealed that the G protein-coupled receptor (GPCR) pathway was up-regulated significantly under the high efficiency condition and treatment with the chemokine, C-C motif ligand 2, a member of the GPCR family, enhanced somatic cell reprogramming 12.3 times. Furthermore, data from the analysis of the signature gene expression profiles of mouse embryonic fibroblasts at 2 days after RTF infection revealed that the genetic modifier, Whsc1l1 (variant 1), also improved the efficiency of somatic cell reprogramming. Finally, comparison of the overall gene expression profiles between the high and low efficiency conditions will provide novel insights into mechanisms underlying somatic cell reprogramming. PMID:22955270

Nagamatsu, Go; Saito, Shigeru; Kosaka, Takeo; Takubo, Keiyo; Kinoshita, Taisuke; Oya, Mototsugu; Horimoto, Katsuhisa; Suda, Toshio

2012-01-01

349

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

PubMed

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

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

2014-02-01

350

Attachment in romantic relationships and somatization.  

PubMed

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

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

2015-02-01

351

Do somatic markers need to be somatic? Analogies from evolution and from hardware interlocks  

E-print Network

Do somatic markers need to be somatic? Analogies from evolution and from hardware interlocks Colin with the concept of hardware interlocks in safety-critical systems. This is used to suggest why it is important of hardware interlocks in engineering design. 2 Could "somatic" markers extend beyond the body? Why do markers

Kent, University of

352

Somatic cells, stem cells, and induced pluripotent stem cells: how do they now contribute to conservation?  

PubMed

More than a decade has now passed since the birth of the first endangered species produced from an adult somatic cell reprogrammed by somatic cell nuclear transfer. At that time, advances made in domestic and laboratory animal species provided the necessary foundation for attempting cutting-edge technologies on threatened and endangered species. In addition to nuclear transfer, spermatogonial stem cell transplantation and induction of pluripotent stem cells have also been explored. Although many basic scientific questions have been answered and more than 30 wild species have been investigated, very few successes have been reported. The majority of studies document numerous obstacles that still need to be overcome to produce viable gametes or embryos for healthy offspring production. This chapter provides an overview of somatic cell and stem cell technologies in different taxa (mammals, fishes, birds, reptiles and amphibians) and evaluates the potential and impact of these approaches for animal species conservation. PMID:25091918

Mastromonaco, Gabriela F; González-Grajales, L Antonio; Filice, Melissa; Comizzoli, Pierre

2014-01-01

353

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. PMID:23175669

Testillano, Pilar S.

2012-01-01

354

Global transcriptome analysis identifies regulated transcripts and pathways activated during oogenesis and early embryogenesis in atlantic cod  

PubMed Central

The molecular mechanisms underlying oogenesis and maternally controlled embryogenesis in fish are not fully understood, especially in marine species. Our aim was to study the egg and embryo transcriptome during oogenesis and early embryogenesis in Atlantic cod. Follicles from oogenesis stages (pre-, early-, and late-vitellogenic), ovulated eggs, and two embryonic stages (blastula, gastrula) were collected from broodstock fish and fertilized eggs. Gene expression profiles were measured in a 44?K oligo microarray consisting of 23,000 cod genes. Hundreds of differentially expressed genes (DEGs) were identified in the follicle stages investigated, implicating a continuous accumulation and degradation of polyadenylated transcripts throughout oogenesis. Very few DEGs were identified from ovulated egg to blastula, showing a more stable maternal RNA pool in early embryonic stages. The highest induction of expression was observed between blastula and gastrula, signifying the onset of zygotic transcription. During early vitellogenesis, several of the most upregulated genes are linked to nervous system signaling, suggesting increasing requirements for ovarian synaptic signaling to stimulate the rapid growth of oocytes. Highly upregulated genes during late vitellogenesis are linked to protein processing, fat metabolism, osmoregulation, and arrested meiosis. One of the genes with the highest upregulation in the ovulated egg is involved in oxidative phosphorylation, reflecting increased energy requirements during fertilization and the first rapid cell divisions of early embryogenesis. In conclusion, this study provides a large-scale presentation of the Atlantic cod's maternally controlled transcriptome in ovarian follicles through oogenesis, ovulated eggs, and early embryos. Mol. Reprod. Dev. 81: 619–635, 2014. © 2014 Wiley Periodicals, Inc. PMID:24687555

Kleppe, Lene; Edvardsen, Rolf Brudvik; Furmanek, Tomasz; Taranger, Geir Lasse; Wargelius, Anna

2014-01-01

355

Cracking the egg: virtual embryogenesis of real robots.  

PubMed

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

Cussat-Blanc, Sylvain; Pollack, Jordan

2014-01-01

356

Systematic determination of patterns of gene expression during Drosophila embryogenesis  

Microsoft Academic Search

BACKGROUND: Cell-fate specification and tissue differentiation during development are largely achieved by the regulation of gene transcription. RESULTS: As a first step to creating a comprehensive atlas of gene-expression patterns during Drosophila embryogenesis, we examined 2,179 genes by in situ hybridization to fixed Drosophila embryos. Of the genes assayed, 63.7% displayed dynamic expression patterns that were documented with 25,690 digital

Pavel Tomancak; Amy Beaton; Richard Weiszmann; Elaine Kwan; ShengQiang Shu; Suzanna E Lewis; Stephen Richards; Michael Ashburner; Volker Hartenstein; Susan E Celniker; Gerald M Rubin

2002-01-01

357

Axes, planes and tubes, or the geometry of embryogenesis  

Microsoft Academic Search

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

Sabine Brauckmann

2011-01-01

358

Embryogenesis from cultured immature inflorescences and nodes of Lolium multiflorum  

Microsoft Academic Search

When cultured on agar-solidified media (based on Murashige and Skoog's formula), immature inflorescences and nodes ofLolium multiflorum underwent several different pathways of morphogenesis. The pathway expressed was dependent upon the type of explant, its\\u000a age and the composition of the culture medium. Immature inflorescences generally produced either leaves and roots or embryoids\\u000a whereas nodes produced axillary shoots or embryoids. Embryogenesis

P. J. Dale; E. Thomas; R. I. S. Brettell; W. Wernicke

1981-01-01

359

Diverse roles of actin in C. elegans early embryogenesis  

PubMed Central

Background The actin cytoskeleton plays critical roles in early development in Caenorhabditis elegans. To further understand the complex roles of actin in early embryogenesis we use RNAi and in vivo imaging of filamentous actin (F-actin) dynamics. Results Using RNAi, we found processes that are differentially sensitive to levels of actin during early embryogenesis. Mild actin depletion shows defects in cortical ruffling, pseudocleavage, and establishment of polarity, while more severe depletion shows defects in polar body extrusion, cytokinesis, chromosome segregation, and eventually, egg production. These defects indicate that actin is required for proper oocyte development, fertilization, and a wide range of important events during early embryogenesis, including proper chromosome segregation. In vivo visualization of the cortical actin cytoskeleton shows dynamics that parallel but are distinct from the previously described myosin dynamics. Two distinct types of actin organization are observed at the cortex. During asymmetric polarization to the anterior, or the establishment phase (Phase I), actin forms a meshwork of microfilaments and focal accumulations throughout the cortex, while during the anterior maintenance phase (Phase II) it undergoes a morphological transition to asymmetrically localized puncta. The proper asymmetric redistribution is dependent on the PAR proteins, while both asymmetric redistribution and morphological transitions are dependent upon PFN-1 and NMY-2. Just before cytokinesis, actin disappears from most of the cortex and is only found around the presumptive cytokinetic furrow. Finally, we describe dynamic actin-enriched comets in the early embryo. Conclusion During early C. elegans embryogenesis actin plays more roles and its organization is more dynamic than previously described. Morphological transitions of F-actin, from meshwork to puncta, as well as asymmetric redistribution, are regulated by the PAR proteins. Results from this study indicate new insights into the cellular and developmental roles of the actin cytoskeleton. PMID:18157918

Velarde, Nathalie; Gunsalus, Kristin C; Piano, Fabio

2007-01-01

360

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

PubMed

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

Lebold, Katie M; Traber, Maret G

2014-01-01

361

Visceral versus Somatic Pain: Similarities and Differences  

Microsoft Academic Search

Inflammatory bowel disease and the irritable bowel syndrome are conditions characterized by chronic pain that generates persistent, hyperalgesic states in many regions of the body. It is difficult to explain the pain of conditions such as inflammatory bowel disease and irritable bowel syndrome by extrapolating directly from what is known about the mechanisms of somatic pain. Visceral and somatic pain

Fernando Cervero

2009-01-01

362

Plant pathology Difference in somatic embryogenetic ability  

E-print Network

Plant pathology Difference in somatic embryogenetic ability of cultured leaf explants of four explants forming somatic embryos varied from 15.2-90.3, mean number of plants regenerat- ed/explant from 1.5-29.5. In terms of their embryogenic competence and plant regeneration the genotypes could be rated in decreasing

Boyer, Edmond

363

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

364

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

365

Establishment of suspension cultures from seeds of plains bluestem [ Bothriochloa ischaemum (L.) Keng.] and regeneration of plants via somatic embryogenesis  

Microsoft Academic Search

Summary  Mature seeds of plains Old World bluestem [Bothriochloa ischaemum (L.) Keng.] were used to initiate suspension cultures. The medium contained the major and minor minerals of Murashige and\\u000a Skoog, Gamborg's B-5 vitamins, 30 g\\/liter sucrose, and 3 mg\\/liter 2,4-dichlorophenoxyacetic acid with or without 12 mM proline at pH 5.5. Cultures contained both embryogenic and nonembryogenic (NE) cells. Suspensions that had

BECKY B. JOHNSONAND; Martin Worthington

1987-01-01

366

In vitro regeneration of Echinacea purpurea L.: Direct somatic embryogenesis and indirect shoot organogenesis in petiole culture  

Microsoft Academic Search

Summary  An in vitro propagation system was developed for Echinacea purpurea L. (purple coneflower), a medicinal plant commonly used in the treatment of colds, flu and related ailments. Echinacea seeds were found to be contaminated with systemic fungi and therefore an optimized minimal concentration of Plant Preservation\\u000a Mixture (PPM) was incorporated in the seed germination medium to recover sterile seedlings. Regeneration

Kristen L. Choffe; Jerrin M. R. Victor; Susan J. Murch; Praveen K. Saxena

2000-01-01

367

In vitro regeneration of chickpea (Cicer arietinum L.): Stimulation of direct organogenesis and somatic embryogenesis by thidiazuron  

Microsoft Academic Search

In vitro regeneration in chickpea (Cicer arietinum L.) was achieved by direct culture of mature seeds on Murashige and Skoog (MS) medium supplemented with either N-phenyl-N'(-1,2,3-thidiazol-5-yl) urea (thidiazuron, TDZ) or N6-benzylaminopurine (BAP). Multiple shoots formed de novo without an intermediary callus phase at the cotyledonary notch region of the seedlings within 2 to 3 weeks of culture initiation. TDZ was

B. N. S. Murthy; Jerrin Victor; Rana P. Singh; R. A. Fletcher; Praveen K. Saxena

1996-01-01

368

Somatic embryogenesis and plant regeneration from root segments of Psoralea corylifolia L., an endangered medicinally important plant  

Microsoft Academic Search

Summary  An efficient plant regeneration protocol has been developed from root explants of Psoralea corylifolia L., an endangered medicinally\\u000a important herbaceous plant species belonging to the family Fabaceae. Nodular embryogenic callus was initiated from young root\\u000a segments cultured on Murashige and Skoog (MS) medium (1962) supplemented with ?-naphthaleneacetic acid (NAA; 2.68–13.42 ?M)\\u000a or 2,4-dichlorophenoxyacetic acid (2.4-D; 2.25–11.25 ?M) in combination with

Suresh Chand; Ashok Kumar Sahrawat

2002-01-01

369

Rapid and efficient transformation of diploid Medicago truncatula and Medicago sativa ssp. falcata lines improved in somatic embryogenesis  

Microsoft Academic Search

We describe a simple and efficient protocol for regeneration-transformation of two diploid Medicago lines: the annual M. truncatula R108-1(c3) and the perennial M. sativa ssp. falcata (L.) Arcangeli PI.564263 selected previously as highly embryogenic genotypes. Here, embryo regeneration of R108-1 to complete\\u000a plants was further improved by three successive in vitro regeneration cycles resulting in the line R108-1(c3). Agrobacterium tumefaciens-mediated

T. H. Trinh; P. Ratet; E. Kondorosi; P. Durand; K. Kamaté; P. Bauer; A. Kondorosi

1998-01-01

370

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

371

Somatic Mutations in Aging, Cancer and Neurodegeneration  

PubMed Central

The somatic mutation theory of aging posits that the accumulation of mutations in the genetic material of somatic cells as a function of time results in a decrease in cellular function. In particular, the accumulation of random mutations inactivates genes that are important for the functioning of the somatic cells of various organ systems of the adult, which results in a decrease in organ function. When the organ function decreases below a critical level, death occurs. A significant amount of research has shown that somatic mutations play an important role in aging and a number of age related pathologies. In this review, we explore evidence for increases in somatic nuclear mutation burden with age and the consequences for aging, cancer, and neurodegeneration. We then review evidence for increases in mitochondrial mutation burden and the consequences for dysfunction in the disease processes. PMID:22079405

Kennedy, Scott R.; Loeb, Lawrence A.; Herr, Alan J.

2012-01-01

372

Somatic Mosaicism in the Human Genome  

PubMed Central

Somatic mosaicism refers to the occurrence of two genetically distinct populations of cells within an individual, derived from a postzygotic mutation. In contrast to inherited mutations, somatic mosaic mutations may affect only a portion of the body and are not transmitted to progeny. These mutations affect varying genomic sizes ranging from single nucleotides to entire chromosomes and have been implicated in disease, most prominently cancer. The phenotypic consequences of somatic mosaicism are dependent upon many factors including the developmental time at which the mutation occurs, the areas of the body that are affected, and the pathophysiological effect(s) of the mutation. The advent of second-generation sequencing technologies has augmented existing array-based and cytogenetic approaches for the identification of somatic mutations. We outline the strengths and weaknesses of these techniques and highlight recent insights into the role of somatic mosaicism in causing cancer, neurodegenerative, monogenic, and complex disease. PMID:25513881

Freed, Donald; Stevens, Eric L.; Pevsner, Jonathan

2014-01-01

373

L E T T E R S miR-34 miRNAs provide a barrier for somatic cell  

E-print Network

L E T T E R S miR-34 miRNAs provide a barrier for somatic cell reprogramming Yong Jin Choi1 regulate this process. Here, we demonstrate that miR-34 microRNAs (miRNAs), particularly miR-34a, exhibit p53-dependent induction during reprogramming. Mir34a deficiency in mice significantly increased

He, Lin

374

Inductive countersupport  

Microsoft Academic Search

Summary The basic idea by means of which Popper and Miller proved the non-existence of inductive probabilistic support in 1983\\/1985\\/1987, is used to prove that inductive probabilistic countersupport does exist. So it seems that after falsification has won over verification on the deductive side of science, countersupport wins over support on the inductive side.

Georg J. W. Dorn

1995-01-01

375

Histological events leading to somatic embryo formation in cultured petioles of alfalfa  

Microsoft Academic Search

Summary  An optimum 10-day exposure of petioles of alfalfa [Medicago sativa ssp.falcata (L.) Arcangeli] to 2,4-dichlorophenoxyacetic acid or 2,4,5-trichlorophenoxyacetic acid results in the semisynchronous production\\u000a of somatic embryos starting about 4 days after transfer to a non-auxin-containing medium. The timing of cell division induction\\u000a in the petiole explants was found to vary depending on the petiole tissue type. Cells adjacent to

C. L. Wenzel; D. C. W. Brown

1991-01-01

376

Induction linacs  

SciTech Connect

The principle of linear induction acceleration is described, and examples are given of practical configurations for induction linacs. These examples include the Advanced Technology Accelerator, Long Pulse Induction Linac, Radial Line Accelerator (RADLAC), and Magnetically-Insulated Electron-Focussed Ion Linac. A related concept, the auto accelerator, is described in which the high-current electron-beam technology in the sub-10 MeV region is exploited to produce electron beams at energies perhaps as high as the 100 to 1000 MeV range. Induction linacs for ions are also discussed. The efficiency of induction linear acceleration is analyzed. (LEW)

Keefe, D.

1986-07-01

377

Encapsulation for somatic gene therapy.  

PubMed

With the human genome project approaching its completion date of 2005, gene-based technology will play an increasingly important role in health-care delivery. Non-autologous somatic gene therapy is a novel application in which non-autologous cell lines engineered to secrete a recombinant protein are enclosed within immunoisolation devices and implanted into all patients requiring the same product for therapy. The development of this technology requires a multi-disciplinary effort towards optimization of the biomaterial used to manufacture the implantable devices and selection of the appropriate cell lines for enclosure. The efficacy of this technology is illustrated in the treatment of dwarfism and lysosomal storage disease in murine models. The potential of a safe and cost-effective gene-based delivery method should have wide applications in treating both classical genetic disorders and non-Mendelian diseases. PMID:10415564

Chang, P L

1999-06-18

378

Somatic Treatments for Mood Disorders  

PubMed Central

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 techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and cranial electric stimulation, (3) surgical approaches, including vagus nerve stimulation, epidural electrical stimulation, and deep brain stimulation, and (4) technologies on the horizon. Additionally, we discuss novel approaches to the optimization of each treatment, and new techniques that are under active investigation. PMID:21976043

Rosa, Moacyr A; Lisanby, Sarah H

2012-01-01

379

Hypothesis: Somatic Mosaicism and Parkinson Disease  

PubMed Central

Mutations causing genetic disorders can occur during mitotic cell division after fertilization, which is called somatic mutations. This leads to somatic mosaicism, where two or more genetically distinct cells are present in one individual. Somatic mutations are the most well studied in cancer where it plays an important role and also have been associated with some neurodegenerative disorders. The study of somatic mosaicism in Parkinson disease (PD) is only in its infancy, and a case with somatic mutation has not yet been described. However, we can speculate that a somatic mutation affecting cells in the central nervous system including substantia nigra dopaminergic neurons could lead to the development of PD through the same pathomechanisms of genetic PD even in the absence of a germ-line mutation. Theoretically, a number of genes could be candidates for genetic analysis for the presence of somatic mosaicism. Among them, SNCA and PARK2 could be the best candidates to analyze. Because analyzing brain tissues in living patients is impossible, alternative tissues could be used to indicate the genetic status of the brain. Performance of the technology is another factor to consider when analyzing the tissues. PMID:25548528

Kim, Han-Joon

2014-01-01

380

The use of centrifugation to study early Drosophila embryogenesis  

NASA Technical Reports Server (NTRS)

By the end of 10th nuclear cycle, the somatic nuclei of the Drosophila embryo have migrated to the periphery of the egg. Centrifugation of embryos did not result in the displacement of these nuclei, since cytoskeletal elements anchor them to the cortex. But, mild centrifugal forces displace the centrally located, nascent yolk nuclei. If this increased sensitivity to hypergravity occurs before the beginning of nuclear differentiation during cycle 8, when the nascent yolk and somatic nuclei physically separate, then it would mark the earliest functional difference between these two lineages.

Abbott, M. K.; Spooner, B. S. (Principal Investigator)

1993-01-01

381

Spatiotemporal expression patterns of mammalian chordin during postgastrulation embryogenesis and in postnatal brain.  

PubMed

Chordin is an antagonist of TGFbeta-like bone morphogenetic proteins (BMPs) that plays roles in dorsoventral axis formation and in induction, maintenance and/or differentiation of neural tissue in early vertebrate embryogenesis. In contrast, little is known concerning possible roles for Chordin at later stages of vertebrate development and in the adult. To provide insights into possible postgastrulation roles for Chordin, we report the spatiotemporal expression patterns of Chordin in 8.5- to 15.5-dpc mouse embryos and in the postnatal mouse brain. Expression of Chordin in the primordia of most major organs from 10.5 dpc, including the brain, lung, heart, liver, kidney, thymus, and gut, suggests multiple functions for Chordin in organogenesis, potentially by means of interactions with TGFbeta-like BMPs. The relatively high levels of Chordin expression in condensing and differentiating cartilage elements from 11.5 dpc indicates a generalized role for Chordin throughout embryonic skeletogenesis. In the postnatal mouse brain, we demonstrate that Chordin is coexpressed with other components of the TGFbeta-like BMP signalling pathway in the cerebellum and hippocampus, sites of high synaptic plasticity, suggesting a role for Chordin in this process. PMID:10767089

Scott, I C; Steiglitz, B M; Clark, T G; Pappano, W N; Greenspan, D S

2000-04-01

382

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. PMID:23017583

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

2012-01-01

383

Bone Morphogenetic Protein 15 (BMP15) Acts as a BMP and Wnt Inhibitor during Early Embryogenesis*  

PubMed Central

Bone morphogenetic protein 15 (BMP15) belongs to an unusual subgroup of the transforming growth factor ? (TGF?) superfamily of signaling ligands as it lacks a key cysteine residue in the mature region required for proper intermolecular dimerization. Naturally occurring BMP15 mutation leads to early ovarian failure in humans, and BMP15 has been shown to activate the Smad1/5/8 pathway in that context. Despite its important role in germ cell specification, the embryological function of BMP15 remains unknown. Surprisingly, we find that during early Xenopus embryogenesis BMP15 acts solely as an inhibitor of the Smad1/5/8 pathway and the Wnt pathway. BMP15 gain-of-function leads to embryos with secondary ectopic heads and to direct neural induction in intact explants. BMP15 inhibits BMP4-mediated epidermal induction in dissociated explants. BMP15 strongly inhibits BRE response induced by BMP4 and blocks phosphorylation and activation of Smad1/5/8 MH2-domain. Mechanistically, BMP15 protein specifically interacts with BMP4 protein, suggesting inhibition upstream of receptor binding. Loss-of-function experiments using morpholinos or a naturally occurring human BMP15 dominant-negative mutant (BMP15-Y235C) leads to embryos lacking head. BMP15-Y235C also eliminates the inhibitory activity of BMP15 on BRE (BMP-responsive element). Finally, we show that BMP15 inhibits the canonical branch of the Wnt pathway, upstream of ?-catenin. We, thus, demonstrate that BMP15 is necessary and sufficient for the specification of dorso-anterior structures and highlight novel mechanisms of BMP15 function that strongly suggest a reinterpretation of its function in ovaries specially for ovarian failure. PMID:19553676

Di Pasquale, Elisa; Brivanlou, Ali H.

2009-01-01

384

Predictive models of molecular machines involved in Caenorhabditis elegans early embryogenesis  

Microsoft Academic Search

Although numerous fundamental aspects of development have been uncovered through the study of individual genes and proteins, system-level models are still missing for most developmental processes. The first two cell divisions of Caenorhabditis elegans embryogenesis constitute an ideal test bed for a system-level approach. Early embryogenesis, including processes such as cell division and establishment of cellular polarity, is readily amenable

Kristin C. Gunsalus; Hui Ge; Aaron J. Schetter; Debra S. Goldberg; Jing-Dong J. Han; Tong Hao; Gabriel F. Berriz; Nicolas Bertin; Jerry Huang; Ling-Shiang Chuang; Ning Li; Ramamurthy Mani; Anthony A. Hyman; Birte Sönnichsen; Christophe J. Echeverri; Frederick P. Roth; Marc Vidal; Fabio Piano

2005-01-01

385

Identification of tightly regulated groups of genes during Drosophila melanogaster embryogenesis  

Microsoft Academic Search

Time-series analysis of whole-genome expression data during Drosophila melanogaster development indicates that up to 86% of its genes change their relative transcript level during embryogenesis. By applying conservative filtering criteria and requiring ‘sharp’ transcript changes, we identified 1534 maternal genes, 792 transient zygotic genes, and 1053 genes whose transcript levels increase during embryogenesis. Each of these three categories is dominated

Sean D Hooper; Stephanie Boue ´; Roland Krause; Lars J Jensen; Christopher E Mason; Murad Ghanim; Kevin P White; Eileen EM Furlong; Peer Bork

2007-01-01

386

Cytokinin and auxin interaction in root stem-cell specification during early embryogenesis  

E-print Network

LETTERS Cytokinin and auxin interaction in root stem-cell specification during early embryogenesis during embryogenesis. It has been known for decades that cyto- kinin and auxin interact to control organ regeneration in cultured tissue1 . Auxin has a critical role in root stem-cell specification in zygotic

Sheen, Jen

387

Processed pseudogenes acquired somatically during cancer development  

PubMed Central

Cancer evolves by mutation, with somatic reactivation of retrotransposons being one such mutational process. Germline retrotransposition can cause processed pseudogenes, but whether this occurs somatically has not been evaluated. Here we screen sequencing data from 660 cancer samples for somatically acquired pseudogenes. We find 42 events in 17 samples, especially non-small cell lung cancer (5/27) and colorectal cancer (2/11). Genomic features mirror those of germline LINE element retrotranspositions, with frequent target-site duplications (67%), consensus TTTTAA sites at insertion points, inverted rearrangements (21%), 5? truncation (74%) and polyA tails (88%). Transcriptional consequences include expression of pseudogenes from UTRs or introns of target genes. In addition, a somatic pseudogene that integrated into the promoter and first exon of the tumour suppressor gene, MGA, abrogated expression from that allele. Thus, formation of processed pseudogenes represents a new class of mutation occurring during cancer development, with potentially diverse functional consequences depending on genomic context. PMID:24714652

Cooke, Susanna L.; Shlien, Adam; Marshall, John; Pipinikas, Christodoulos P.; Martincorena, Inigo; Tubio, Jose M.C.; Li, Yilong; Menzies, Andrew; Mudie, Laura; Ramakrishna, Manasa; Yates, Lucy; Davies, Helen; Bolli, Niccolo; Bignell, Graham R.; Tarpey, Patrick S.; Behjati, Sam; Nik-Zainal, Serena; Papaemmanuil, Elli; Teixeira, Vitor H.; Raine, Keiran; O’Meara, Sarah; Dodoran, Maryam S.; Teague, Jon W.; Butler, Adam P.; Iacobuzio-Donahue, Christine; Santarius, Thomas; Grundy, Richard G.; Malkin, David; Greaves, Mel; Munshi, Nikhil; Flanagan, Adrienne M.; Bowtell, David; Martin, Sancha; Larsimont, Denis; Reis-Filho, Jorge S.; Boussioutas, Alex; Taylor, Jack A.; Hayes, Neil D.; Janes, Sam M.; Futreal, P. Andrew; Stratton, Michael R.; McDermott, Ultan; Campbell, Peter J.; Provenzano, Elena; van de Vijver, Marc; Richardson, Andrea L.; Purdie, Colin; Pinder, Sarah; Mac Grogan, Gaetan; Vincent-Salomon, Anne; Larsimont, Denis; Grabau, Dorthe; Sauer, Torill; Garred, Řystein; Ehinger, Anna; Van den Eynden, Gert G.; van Deurzen, C.H.M; Salgado, Roberto; Brock, Jane E.; Lakhani, Sunil R.; Giri, Dilip D.; Arnould, Laurent; Jacquemier, Jocelyne; Treilleux, Isabelle; Caldas, Carlos; Chin, Suet-Feung; Fatima, Aquila; Thompson, Alastair M.; Stenhouse, Alasdair; Foekens, John; Martens, John; Sieuwerts, Anieta; Brinkman, Arjen; Stunnenberg, Henk; Span, Paul N.; Sweep, Fred; Desmedt, Christine; Sotiriou, Christos; Thomas, Gilles; Broeks, Annegein; Langerod, Anita; Aparicio, Samuel; Simpson, Peter T.; van ’t Veer, Laura; Erla Eyfjörd, Jórunn; Hilmarsdottir, Holmfridur; Jonasson, Jon G.; Břrresen-Dale, Anne-Lise; Lee, Ming Ta Michael; Wong, Bernice Huimin; Tan, Benita Kiat Tee; Hooijer, Gerrit K.J.

2014-01-01

388

Somatic retrotransposition in the cancer genome  

E-print Network

Cancer is a complex disease of the genome exhibiting myriad somatic mutations, from single nucleotide changes to various chromosomal rearrangements. The technological advances of next-generation sequencing enable high-throughput ...

Helman, Elena

2014-01-01

389

Vasoactive intestinal peptide antagonist treatment during mouse embryogenesis impairs social behavior and cognitive function of adult male offspring  

Microsoft Academic Search

Vasoactive intestinal peptide (VIP) is a regulator of rodent embryogenesis during the period of neural tube closure. VIP enhanced growth in whole cultured mouse embryos; treatment with a VIP antagonist during embryogenesis inhibited growth and development. VIP antagonist treatment during embryogenesis also had permanent effects on adult brain chemistry and impaired social recognition behavior in adult male mice. The neurological

Joanna M. Hill; Katrina Cuasay; Daniel T. Abebe

2007-01-01

390

Human somatic cell nuclear transfer and cloning.  

PubMed

This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer (cloning)," last published in Fertil Steril 2000;74:873-6. PMID:22795681

2012-10-01

391

(Somatic mutations in nuclear and mitochondrial DNA)  

SciTech Connect

The study is concerned the design of new assays that may detect rare somatic mutations in nuclear and mitochondrial DNA, which may increase upon exposure to mutagens, and thus become a marker of human exposure to such mutagens. Two assays for somatic mutation were presented, one for mitochondrial DNA deletions which was developed by the author, and one for deletions of the ADA gene which resides in the nucleus.

Not Available

1992-01-01

392

Illness behavior and somatization in general practice.  

PubMed

In the primary care setting, the early recognition that a patient has psychological problems is frequently hindered by the deceptive mode of presentation known as somatization. In a cross-sectional survey of patients attending suburban General Practitioners in a large metropolitan city, the General Health Questionnaire-30 (GHQ-30) and the Illness Behavior Questionnaire (IBQ) were completed by 201 patients. A comparison was made between somatizing and nonsomatizing patients with new inceptions of illness in terms of the risk of the presence of a mild nonpsychotic psychiatric illness and aspects of illness behavior. For the group as a whole, somatizing patients were more likely to be older and female. Male somatizers differed from male nonsomatizers by showing greater disease conviction and affective disturbance and more readiness to acknowledge difficulties in their lives other than health problems. No differences were found between female somatizing and nonsomatizing patients. We conclude that, while male patients who somatize psychological distress may be distinguished from male nonsomatizers early in their illness, in terms of their illness behavior, these differences are not seen as early distinguishing characteristics in female patients who present to their General Practitioners with physical problems for which no organic cause can be established. PMID:8910247

Scicchitano, J; Lovell, P; Pearce, R; Marley, J; Pilowsky, I

1996-09-01

393

Arsenic Exposure to Killifish During Embryogenesis Alters Muscle Development  

PubMed Central

Epidemiological studies have correlated arsenic exposure in drinking water with adverse developmental outcomes such as stillbirths, spontaneous abortions, neonatal mortality, low birth weight, delays in the use of musculature, and altered locomotor activity. Killifish (Fundulus heteroclitus) were used as a model to help to determine the mechanisms by which arsenic could impact development. Killifish embryos were exposed to three different sodium arsenite concentrations and were collected at 32 h post-fertilization (hpf), 42 hpf, 168 hpf, or < 24 h post-hatch. A killifish oligo microarray was developed and used to examine gene expression changes between control and 25-ppm arsenic-exposed hatchlings. With artificial neural network analysis of the transcriptomic data, accurate prediction of each group (control vs. arsenic-exposed embryos) was obtained using a small subset of only 332 genes. The genes differentially expressed include those involved in cell cycle, development, ubiquitination, and the musculature. Several of the genes involved in cell cycle regulation and muscle formation, such as fetuin B, cyclin D–binding protein 1, and CapZ, were differentially expressed in the embryos in a time- and dose-dependent manner. Examining muscle structure in the hatchlings showed that arsenic exposure during embryogenesis significantly reduces the average muscle fiber size, which is coupled with a significant 2.1- and 1.6-fold upregulation of skeletal myosin light and heavy chains, respectively. These findings collectively indicate that arsenic exposure during embryogenesis can initiate molecular changes that appear to lead to aberrant muscle formation. PMID:22058191

Gaworecki, Kristen M.; Chapman, Robert W.; Neely, Marion G.; D’Amico, Angela R.; Bain, Lisa J.

2012-01-01

394

Systematic determination of patterns of gene expression during Drosophila embryogenesis  

PubMed Central

Background Cell-fate specification and tissue differentiation during development are largely achieved by the regulation of gene transcription. Results As a first step to creating a comprehensive atlas of gene-expression patterns during Drosophila embryogenesis, we examined 2,179 genes by in situ hybridization to fixed Drosophila embryos. Of the genes assayed, 63.7% displayed dynamic expression patterns that were documented with 25,690 digital photomicrographs of individual embryos. The photomicrographs were annotated using controlled vocabularies for anatomical structures that are organized into a developmental hierarchy. We also generated a detailed time course of gene expression during embryogenesis using microarrays to provide an independent corroboration of the in situ hybridization results. All image, annotation and microarray data are stored in publicly available database. We found that the RNA transcripts of about 1% of genes show clear subcellular localization. Nearly all the annotated expression patterns are distinct. We present an approach for organizing the data by hierarchical clustering of annotation terms that allows us to group tissues that express similar sets of genes as well as genes displaying similar expression patterns. Conclusions Analyzing gene-expression patterns by in situ hybridization to whole-mount embryos provides an extremely rich dataset that can be used to identify genes involved in developmental processes that have been missed by traditional genetic analysis. Systematic analysis of rigorously annotated patterns of gene expression will complement and extend the types of analyses carried out using expression microarrays. PMID:12537577

Tomancak, Pavel; Beaton, Amy; Weiszmann, Richard; Kwan, Elaine; Shu, ShengQiang; Lewis, Suzanna E; Richards, Stephen; Ashburner, Michael; Hartenstein, Volker; Celniker, Susan E; Rubin, Gerald M

2002-01-01

395

Transcriptomic study of the red palm weevil Rhynchophorus ferrugineus embryogenesis.  

PubMed

The red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae), is an invasive, concealed and destructive tissue borer, and it becomes a lethal pest of the palm family of plants and has been reported to attack 20 palm species around the globe. Here we report a systematic transcriptomic study on embryogenesis of RPW, where we analyze the transcriptomes across five developmental stages of RPW embryogenesis, involving four embryonic stages (E1, E2, E3 and E4) and one larval stage (L1). Using the RNA-seq and next-generation platforms, we generated 80 to 91 million reads for each library and assemble 22 532 genes that are expressed at different embryonic stages. Among the total transcripts from the five embryonic development stages, we found that 30.45 % are differentially expressed, 10.10?% show stage-specificity and even a larger fraction, 62.88 %, exhibit constitutive expression in all the stages. We also analyzes the expression dynamics of several conserved signaling pathways (such as Hedgehog, JAK-STAT, Notch, TGF-?, Ras/MAPK and Wnt), as well as key developmental genes, including those related to apoptosis, axis formation, Hox complex, neurogenesis and segmentation. The datasets provide an essential resource for gene annotation and RPW functional genomics, including studies by using tools and concepts from multiple disciplines, such as development, physiology, biochemistry, molecular biology and genetics. PMID:24347559

Yin, An; Pan, Linlin; Zhang, Xiaowei; Wang, Lei; Yin, Yuxin; Jia, Shangang; Liu, Wanfei; Xin, Chengqi; Liu, Kan; Yu, Xiaoguang; Sun, Gaoyuan; Al-Hudaib, Khalid; Hu, Songnian; Al-Mssallem, Ibrahim S; Yu, Jun

2015-02-01

396

Pilates, Mindfulness and Somatic Education  

PubMed Central

The Pilates Method is a form of somatic education with the potential to cultivate mindfulness – a mental quality associated with overall well-being. However, controlled studies are needed to determine whether changes in mindfulness are specific to the Pilates Method or also result from other forms of exercise. This quasi-experimental study compared Pilates Method mat classes and recreational exercise classes on measures of mindfulness and well-being at the beginning, middle and end of a 15 week semester. Total mindfulness scores increased overall for the Pilates Method group but not for the exercise control group, and these increases were directly related to end of semester ratings of self-regulatory self-efficacy, perceived stress and mood. Findings suggest that the Pilates Method specifically enhances mindfulness, and these increases are associated with other measures of wellness. The changes in mindfulness identified in this study support the role of the Pilates Method in the mental well-being of its practitioners and its potential to support dancers’ overall well-being. PMID:25328542

Caldwell, Karen; Quin, Rebecca; Harrison, Mandy; Greeson, Jeffrey

2014-01-01

397

GA3 stimulates the formation and germination of somatic embryos and the expression of a KNOTTED-like homeobox gene of Cocos nucifera (L.).  

PubMed

The micropropagation of coconut palm has progressed rapidly; yet, there are constraints with regard to the number of somatic embryos formed and their germination. To overcome these, we tested the effect of gibberellic acid and characterized genes of the KNOX family. Gibberellic acid at 0.5 muM increased 1.5-fold the number of calli forming somatic embryos and twofold the number of somatic embryos per callus, calli with germinating embryos and the number of germinating somatic embryos per callus. With regard to the study of KNOX family genes, the complete sequences of two KNOX-like genes were obtained for CnKNOX1 and CnKNOX2. The deduced amino acid sequence of both showed highly conserved domains characteristic of KNOX genes. CnKNOX1 showed high homology with KNOX class I proteins. CnKNOX1 expression was detected throughout the embryogenesis process except in somatic embryos at the pro-globular stage, and was highest in somatic embryos at the coleoptilar stage. No detection of CnKNOX1 expression occurred in calli with aberrant embryos. The addition of gibberellic acid stimulated the expression of CnKNOX1 earlier and the relative expression at all stages was higher. CnKNOX2 expression occurred at all stages peaking at the globular stage, but gibberellic acid treatment decreased the expression. Gene expression was also analyzed in tissues of different organs of adult palms. With CnKNOX1, high level of expression was found in tissues of organs with, but not in those without, meristem, whereas CnKNOX2 expression was detected in tissues with and also in those without meristem. PMID:20582418

Montero-Córtes, M; Sáenz, Luis; Córdova, I; Quiroz, A; Verdeil, J-L; Oropeza, C

2010-09-01

398

Somatic Mutations in Cerebral Cortical Malformations  

PubMed Central

BACKGROUND Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated. METHODS Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, ?200×) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing. RESULTS Validated, causal mutations were found in 27 persons (17%; range, 10 to 30% for each phenotype). Mutations were somatic in 8 of the 27 (30%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria. CONCLUSIONS Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.) PMID:25140959

Jamuar, Saumya S.; Lam, Anh-Thu N.; Kircher, Martin; D'Gama, Alissa M.; Wang, Jian; Barry, Brenda J.; Zhang, Xiaochang; Hill, Robert Sean; Partlow, Jennifer N.; Rozzo, Aldo; Servattalab, Sarah; Mehta, Bhaven K.; Topcu, Meral; Amrom, Dina; Andermann, Eva; Dan, Bernard; Parrini, Elena; Guerrini, Renzo; Scheffer, Ingrid E.; Berkovic, Samuel F.; Leventer, Richard J.; Shen, Yiping; Wu, Bai Lin; Barkovich, A. James; Sahin, Mustafa; Chang, Bernard S.; Bamshad, Michael; Nickerson, Deborah A.; Shendure, Jay; Poduri, Annapurna; Yu, Timothy W.; Walsh, Christopher A.

2014-01-01

399

Somatic genome variations in health and disease.  

PubMed

It is hard to imagine that all the cells of the human organism (about 10(14)) share identical genome. Moreover, the number of mitoses (about 10(16)) required for the organism's development and maturation during ontogeny suggests that at least a proportion of them could be abnormal leading, thereby, to large-scale genomic alterations in somatic cells. Experimental data do demonstrate such genomic variations to exist and to be involved in human development and interindividual genetic variability in health and disease. However, since current genomic technologies are mainly based on methods, which analyze genomes from a large pool of cells, intercellular or somatic genome variations are significantly less appreciated in modern bioscience. Here, a review of somatic genome variations occurring at all levels of genome organization (i.e. DNA sequence, subchromosomal and chromosomal) in health and disease is presented. Looking through the available literature, it was possible to show that the somatic cell genome is extremely variable. Additionally, being mainly associated with chromosome or genome instability (most commonly manifesting as aneuploidy), somatic genome variations are involved in pathogenesis of numerous human diseases. The latter mainly concerns diseases of the brain (i.e. autism, schizophrenia, Alzheimer's disease) and immune system (autoimmune diseases), chromosomal and some monogenic syndromes, cancers, infertility and prenatal mortality. Taking into account data on somatic genome variations and chromosome instability, it becomes possible to show that related processes can underlie non-malignant pathology such as (neuro)degeneration or other local tissue dysfunctions. Together, we suggest that detection and characterization of somatic genome behavior and variations can provide new opportunities for human genome research and genetics. PMID:21358982

Iourov, I Y; Vorsanova, S G; Yurov, Y B

2010-09-01

400

Somatic Genome Variations in Health and Disease  

PubMed Central

It is hard to imagine that all the cells of the human organism (about 1014) share identical genome. Moreover, the number of mitoses (about 1016) required for the organism’s development and maturation during ontogeny suggests that at least a proportion of them could be abnormal leading, thereby, to large-scale genomic alterations in somatic cells. Experimental data do demonstrate such genomic variations to exist and to be involved in human development and interindividual genetic variability in health and disease. However, since current genomic technologies are mainly based on methods, which analyze genomes from a large pool of cells, intercellular or somatic genome variations are significantly less appreciated in modern bioscience. Here, a review of somatic genome variations occurring at all levels of genome organization (i.e. DNA sequence, subchromosomal and chromosomal) in health and disease is presented. Looking through the available literature, it was possible to show that the somatic cell genome is extremely variable. Additionally, being mainly associated with chromosome or genome instability (most commonly manifesting as aneuploidy), somatic genome variations are involved in pathogenesis of numerous human diseases. The latter mainly concerns diseases of the brain (i.e. autism, schizophrenia, Alzheimer’s disease) and immune system (autoimmune diseases), chromosomal and some monogenic syndromes, cancers, infertility and prenatal mortality. Taking into account data on somatic genome variations and chromosome instability, it becomes possible to show that related processes can underlie non-malignant pathology such as (neuro)degeneration or other local tissue dysfunctions. Together, we suggest that detection and characterization of somatic genome behavior and variations can provide new opportunities for human genome research and genetics. PMID:21358982

Iourov, I.Y.; Vorsanova, S.G.; Yurov, Y.B.

2010-01-01

401

Embryonic and somatic cell cloning.  

PubMed

Revolutionary opportunities in biology, medicine and agriculture arise from the observation that offspring are obtained after nuclear transfer if somatic donor cells are induced to become quiescent. Exploitation of many of these opportunities will depend upon optimizing procedures for nuclear transfer. This may come about through an understanding of the means by which factors in the oocyte cytoplasm act upon the DNA of the transferred nucleus to regulate gene expression. Similarly, research will extend the procedure to other species. This technology may be used for embryo production, the introduction of genetic change and the derivation of cells needed to treat human diseases. Groups of genetically identical animals will be used in research to control genetic variation and to allow transfer of cells between individuals. In agriculture, production of a small number of clones will separate genetic and environmental effects, whereas production of larger numbers of offspring will disseminate genetic improvement from nucleus herds. Precise genetic modification will be achieved by site specific recombination in the donor cells before nuclear transfer. In all mammals it will become possible to define the role of any gene product and to analyse the mechanisms that regulate gene expression. Medical uses of these techniques will include the production of proteins needed to treat disease and the supply of organs such as hearts, livers and kidneys from pigs. As genome mapping projects identify loci associated with traits of commercial importance in agriculture then gene targeting will be used to study this effect. Finally, cells capable of differentiation into any of the tissues of a patient will provide treatment for diseases reflecting damage to a specific cell population that neither repairs nor replaces itself. PMID:10612470

Wilmut, I; Young, L; Campbell, K H

1998-01-01

402

Potassium and carrot embryogenesis: Are K + channels necessary for development?  

Microsoft Academic Search

The expression pattern of the KDC1gene, coding for an inwardly-rectifying K+ channel of Daucuscarota, is described in several embryo stages and seedling tissues. Relative quantitative RT-PCR experiments indicated that, during (somatic) embryonic development, the KDC1 transcript appears as early as the globular stage and that the transcript level remains constant throughout the successive heart and torpedo stages. Thereafter, the KDC1

Alex Costa; Carpaneto Armando; Varotto Serena; Formentin Elide; Marin Oriano; Barizza Elisabetta; Terzi Mario; Gambale Franco; Lo Schiavo Fiorella

2004-01-01

403

Induction voidmeter  

DOEpatents

An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

Anderson, Thomas T. (Downers Grove, IL); Roop, Conard J. (Lockport, IL); Schmidt, Kenneth J. (Midlothian, IL); Brewer, John (Oak Lawn, IL)

1986-01-01

404

Induction voidmeter  

DOEpatents

An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

1983-12-21

405

Somatic symptoms in those with performance and interaction anxiety.  

PubMed

This study (n = 304) examined the relationship between somatic symptoms and social anxiety. Significant differences in the experience of somatic symptoms were found among four groups (i.e. performance anxious, interaction anxious, generalized socially anxious, and controls). Post hoc analyses revealed that those who exceeded the clinical cutoff for generalized social anxiety exhibited more somatic symptoms than those who exceeded the clinical cutoff in the other two social anxiety domains or controls. Individuals in each group exhibited more somatic symptoms than controls, but subtypes did not differ in the amount of somatic symptoms experienced. Additionally, regression analyses revealed that type of somatic symptoms experienced varied depending on subtype. PMID:23818506

May, Anna C; Rudy, Brittany M; Davis, Thompson E; Jenkins, Whitney S; Reuther, Erin T; Whiting, Sara E

2014-11-01

406

Transcriptional changes in somatic cells recovered from embryonic stem-somatic heterokaryons.  

PubMed

Following fusion, embryonic stem cells (ESCs) are capable of reprogramming somatic cells in cell hybrids. It has also been shown that transcriptional changes can occur in a heterokaryon, without nuclear hybridization. However, it is unclear whether these changes can be sustained after the removal of the dominant nucleus. In this study, we analyze the changes in embryonic stem (ES)-somatic heterokaryons following the removal of the ESCs nucleus. We also show that after ES-somatic cell fusion using tetraploid ESCs, a heterokaryon can be reverted to an autologous diploid state by differential enucleation of the denser tetraploid ES nucleus. To recover somatic cells from ES-somatic heterokaryons, we fused tetraploid ESCs containing the thymidine kinase (TK) suicide gene with mesenchymal stem cells containing a green fluorescent protein (GFP) transgene under the control of the OCT4 promoter. Following post-fusion enucleation (PFE), negative selection against the tetraploid ES genome was achieved using ganciclovir. The resulting GFP-positive clones were analyzed and shown to have undergone changes in growth characteristics, alkaline phosphatase activity, and gene expression using RT-PCR and microarray analysis. These results demonstrate that a change in transcriptional expression can be detected in somatic cells after the removal of the ES nucleus from ES-somatic heterokaryons. PMID:19222348

Sumer, Huseyin; Jones, Karen L; Liu, Jun; Rollo, Benjamin N; van Boxtel, Antonius L; Pralong, Daniele; Verma, Paul J

2009-11-01

407

Coherent Somatic Mutation in Autoimmune Disease  

PubMed Central

Background Many aspects of autoimmune disease are not well understood, including the specificities of autoimmune targets, and patterns of co-morbidity and cross-heritability across diseases. Prior work has provided evidence that somatic mutation caused by gene conversion and deletion at segmentally duplicated loci is relevant to several diseases. Simple tandem repeat (STR) sequence is highly mutable, both somatically and in the germ-line, and somatic STR mutations are observed under inflammation. Results Protein-coding genes spanning STRs having markers of mutability, including germ-line variability, high total length, repeat count and/or repeat similarity, are evaluated in the context of autoimmunity. For the initiation of autoimmune disease, antigens whose autoantibodies are the first observed in a disease, termed primary autoantigens, are informative. Three primary autoantigens, thyroid peroxidase (TPO), phogrin (PTPRN2) and filaggrin (FLG), include STRs that are among the eleven longest STRs spanned by protein-coding genes. This association of primary autoantigens with long STR sequence is highly significant (). Long STRs occur within twenty genes that are associated with sixteen common autoimmune diseases and atherosclerosis. The repeat within the TTC34 gene is an outlier in terms of length and a link with systemic lupus erythematosus is proposed. Conclusions The results support the hypothesis that many autoimmune diseases are triggered by immune responses to proteins whose DNA sequence mutates somatically in a coherent, consistent fashion. Other autoimmune diseases may be caused by coherent somatic mutations in immune cells. The coherent somatic mutation hypothesis has the potential to be a comprehensive explanation for the initiation of many autoimmune diseases. PMID:24988487

Ross, Kenneth Andrew

2014-01-01

408

Processed pseudogene insertions in somatic cells  

PubMed Central

Processed pseudogenes are copies of messenger RNAs that have been reverse transcribed into DNA and inserted into the genome using the enzymatic activities of active L1 elements. Processed pseudogenes generally lack introns, end in a 3’ poly A, and are flanked by target site duplications. Until recently, very few polymorphic processed pseudogenes had been discovered in mammalian genomes. Now several studies have found a number of polymorphic processed pseudogenes in humans. Moreover, processed pseudogenes can occur in somatic cells, including in various cancers and in early fetal development. One recent somatic insertion of a processed pseudogene has caused a Mendelian X-linked disease, chronic granulomatous disease. PMID:25184004

2014-01-01

409

Identification of Late Embryogenesis Abundant (LEA) Protein Putative Interactors Using Phage Display.  

PubMed

Arabidopsis thaliana seeds without functional SEED MATURATION PROTEIN1 (SMP1), a boiling soluble protein predicted to be of intrinsic disorder, presumed to be a LATE EMBRYOGENESIS ABUNDANT (LEA) family protein based on sequence homology, do not enter secondary dormancy after 3 days at 40 °C. We hypothesized that SMP1 may protect a heat labile protein involved in the promotion of secondary dormancy. Recombinant SMP1 and GmPM28, its soybean (Glycine max), LEA4 homologue, protected the labile GLUCOSE-6-PHOSPHATE DEHYROGENASE enzyme from heat stress, as did a known protectant, Bovine Serum Albumin, whether the LEA protein was in solution or attached to the bottom of microtiter plates. Maintenance of a biological function for both recombinant LEA proteins when immobilized encouraged a biopanning approach to screen for potential protein interactors. Phage display with two Arabidopsis seed, T7 phage, cDNA libraries, normalized for transcripts present in the mature, dehydrated, 12-, 24-, or 36-h imbibed seeds, were used in biopans against recombinant SMP1 and GmPM28. Phage titer increased considerably over four rounds of biopanning for both LEA proteins, but not for BSA, at both 25 and at 41 °C, regardless of the library used. The prevalence of multiple, independent clones encoding portions of specific proteins repeatedly retrieved from different libraries, temperatures and baits, provides evidence suggesting these LEA proteins are discriminating which proteins they protect, a novel finding. The identification of putative LEA-interacting proteins provides targets for reverse genetic approaches to further dissect the induction of secondary dormancy in seeds in response to heat stress. PMID:22837651

Kushwaha, Rekha; Lloyd, Taylor D; Schäfermeyer, Kim R; Kumar, Santosh; Downie, Allan Bruce

2012-01-01

410

Cervical epidural steroid injection for refractory somatic tinnitus.  

PubMed

Somatic tinnitus is a common disorder, yet few treatments described in the literature have demonstrated strong efficacy. We report a case of a 61-year-old male with refractory somatic tinnitus, temporally related to a prior bacterial otitis media, wherein auditory symptoms were successfully treated with cervical epidural injections of long-acting corticosteroid. We discuss the proposed mechanism of somatic tinnitus and the means by which neuraxial steroids may inhibit somatic tinnitus symptoms. PMID:25353360

McCormick, Zachary L; Walega, David R

2015-02-01

411

Animal cloning by somatic cell nuclear transfer.  

PubMed

Animal cloning is becoming increasingly useful for its applications in biological inquiry and for its potential use in pharmaceutical, medical, and agricultural fields. Due to the complexity of the numerous steps required in reconstructing oocytes by nuclear transfer, detailed protocols are required to minimize the developmental damages inflicted during these manipulations and to standardize procedures across laboratories. Moreover, because oogenesis and early embryogenesis differ widely among mammalian species, it is essential that protocols be adapted according to each species concerned. Our objective here is to detail the protocols that have been most successful in producing laboratory and domestic animal clones. PMID:19495710

Smith, Lawrence C; Yoo, Jae-Gyu

2009-01-01

412

Prevalence of somatic alterations in the colorectal cancer cell genome  

Microsoft Academic Search

Although a small fraction of human cancers have increased rates of somatic mutation because of known deficiencies in DNA repair, little is known about the prevalence of somatic alterations in the vast majority of human cancers. To systematically assess nonsynonymous somatic alterations in colorectal neoplasia, we used DNA sequencing to analyze 3.2 Mb of coding tumor DNA comprising 1,811 exons

Tian-Li Wang; Carlo Rago; Natalie Silliman; Janine Ptak; Sanford Markowitz; James K. V. Willson; Giovanni Parmigiani; Kenneth W. Kinzler; Bert Vogelstein; Victor E. Velculescu

2002-01-01

413

Somatic Symptoms in Traumatized Children and Adolescents  

ERIC Educational Resources Information Center

Childhood exposure to trauma has been associated with increased rates of somatic symptoms (SS), which may contribute to diminished daily functioning. One hundred and sixty-one children residing at a residential treatment home who had experienced neglect and/or abuse were administered the Trauma Symptom Checklist for Children (TSCC), the…

Kugler, Brittany B.; Bloom, Marlene; Kaercher, Lauren B.; Truax, Tatyana V.; Storch, Eric A.

2012-01-01

414

Somatic Consequences of Violence Against Women  

Microsoft Academic Search

rapidly growing literature on the somatic, nonpsychiatric effects of vi- olence on women's health is reviewed, including rape, battery, and the adult consequences of child sexual abuse. The sequelae of these victimizations are summarized with consideration of acute effects (genital and nongenital injuries, sexually transmitted disease, and pregnancy), late consequences (chronic pel- vic pain and other forms of chronic pain,

Mary P. Koss; Lynette Heslet

415

A model system for analyzing somatic  

E-print Network

A model system for analyzing somatic mutations in Drosophila melanogaster Ana Maria Garcia1Z mutation reporter system in D. melanogaster, which complements existing systems in the mouse. The results. melanogaster spot tests2,3. Direct methods are available, but they are restricted to point mutations

Cai, Long

416

Art Therapy, Somatization, and Narcissistic Identification  

Microsoft Academic Search

This article describes how art therapy can benefit patients with somatic complaints and those suffering from functional gastrointestinal disorders such as dyspepsia. Some psychosomatic disorders may be linked to narcissistic identification and\\/or depressive components. Mushatt (1989) depicts the essence of narcissism as a residue of the earliest symbiotic state, shown when body and external world are one. She points out

Louise Lacroix; Leland Peterson; Pierre Verrier

2001-01-01

417

The int-2 proto-oncogene is responsible for induction of the inner ear  

Microsoft Academic Search

THE int-2 proto-oncogene encodes several products related to the fibroblast growth factor (FGF) family1,2. FGFs have been associated with mesoderm induction in the amphibian embryo2,3 and int-2 has a distinct pattern of expression throughout development in vertebrates4,5. But evidence for a function of int-2 in embryo-genesis has been lacking. In the mouse embryo, int-2 transcripts have been detected in the

Juan Represa; Yolanda León; Cristina Miner; Fernando Giraldez

1991-01-01

418

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

419

Embryogenesis in the reef-building coral Acropora spp.  

PubMed

Embryogenesis in the reef building corals Acropora intermedia, A. solitaryensis, A. hyacinthus, A. digitifera, and A. tenuis was studied in detail at the morphological level, and the relationships among the animal pole, blastopore, and mouth were investigated for the first time in corals. These species showed essentially the same sequence of development. The embryo undergoes spiral-like holoblastic cleavage despite the presence of a dense isolecithal yolk. After the morula stage, the embryo enters the "prawn-chip" stage, which consists of an irregularly shaped cellular bilayer. The embryo begins to roll inward to form the bowl stage; the round shape observed during this stage suggests that it may be the beginning of gastrulation. However, the blastopore closes and the stomodeum (mouth and pharynx) is formed via invagination at a site near the closed blastopore. During the planula stage, a concavity forms in the aboral region in conjunction with numerous spirocysts, suggesting that spirocysts are used to attach to the substrate before the onset of metamorphosis. PMID:18271633

Okubo, Nami; Motokawa, Tatsuo

2007-12-01

420

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.

421

Modeling cell-cycle synchronization during embryogenesis in Xenopus laevis  

NASA Astrophysics Data System (ADS)

A widely conserved aspect of embryogenesis is the ability to synchronize nuclear divisions post-fertilization. How is synchronization achieved? Given a typical protein diffusion constant of 10 ?m^2sec, and an embryo length of 1mm, it would take diffusion many hours to propagate a signal across the embryo. Therefore, synchrony cannot be attained by diffusion alone. We hypothesize that known autocatalytic reactions of cell-cycle components make the embryo an ``active medium'' in which waves propagate much faster than diffusion, enforcing synchrony. We report on robust spatial synchronization of components of the core cell cycle circuit based on a mathematical model previously determined by in vitro experiments. In vivo, synchronized divisions are preceded by a rapid calcium wave that sweeps across the embryo. Experimental evidence supports the hypothesis that increases in transient calcium levels lead to derepression of a negative feedback loop, allowing cell divisions to start. Preliminary results indicate a novel relationship between the speed of the initial calcium wave and the ability to achieve synchronous cell divisions.

McIsaac, R. Scott; Huang, K. C.; Sengupta, Anirvan; Wingreen, Ned

2010-03-01

422

Somatic progenitor cell vulnerability to mitochondrial DNA mutagenesis underlies progeroid phenotypes in Polg mutator mice.  

PubMed

Somatic stem cell (SSC) dysfunction is typical for different progeroid phenotypes in mice with genomic DNA repair defects. MtDNA mutagenesis in mice with defective Polg exonuclease activity also leads to progeroid symptoms, by an unknown mechanism. We found that Polg-Mutator mice had neural (NSC) and hematopoietic progenitor (HPC) dysfunction already from embryogenesis. NSC self-renewal was decreased in vitro, and quiescent NSC amounts were reduced in vivo. HPCs showed abnormal lineage differentiation leading to anemia and lymphopenia. N-acetyl-L-cysteine treatment rescued both NSC and HPC abnormalities, suggesting that subtle ROS/redox changes, induced by mtDNA mutagenesis, modulate SSC function. Our results show that mtDNA mutagenesis affected SSC function early but manifested as respiratory chain deficiency in nondividing tissues in old age. Deletor mice, having mtDNA deletions in postmitotic cells and no progeria, had normal SSCs. We propose that SSC compartment is sensitive to mtDNA mutagenesis, and that mitochondrial dysfunction in SSCs can underlie progeroid manifestations. PMID:22225879

Ahlqvist, Kati J; Hämäläinen, Riikka H; Yatsuga, Shuichi; Uutela, Marko; Terzioglu, Mügen; Götz, Alexandra; Forsström, Saara; Salven, Petri; Angers-Loustau, Alexandre; Kopra, Outi H; Tyynismaa, Henna; Larsson, Nils-Göran; Wartiovaara, Kirmo; Prolla, Tomas; Trifunovic, Aleksandra; Suomalainen, Anu

2012-01-01

423

Autosomal dominant polycystic kidney disease caused by somatic and germline mosaicism.  

PubMed

Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous genetic disorder caused by loss of function mutations of PKD1 or PKD2 genes. Although PKD1 is highly polymorphic and the new mutation rate is relatively high, the role of mosaicism is incompletely defined. Herein, we describe the molecular analysis of ADPKD in a 19-year-old female proband and her father. The proband had a PKD1 truncation mutation c.10745dupC (p.Val3584ArgfsX43), which was absent in paternal peripheral blood lymphocytes (PBL). However, very low quantities of this mutation were detected in the father's sperm DNA, but not in DNA from his buccal cells or urine sediment. Next generation sequencing (NGS) analysis determined the level of this mutation in the father's PBL, buccal cells and sperm to be ?3%, 4.5% and 10%, respectively, consistent with somatic and germline mosaicism. The PKD1 mutation in ?10% of her father's sperm indicates that it probably occurred early in embryogenesis. In ADPKD cases where a de novo mutation is suspected because of negative PKD gene testing of PBL, additional evaluation with more sensitive methods (e.g. NGS) of the proband PBL and paternal sperm can enhance detection of mosaicism and facilitate genetic counseling. PMID:24641620

Tan, A Y; Blumenfeld, J; Michaeel, A; Donahue, S; Bobb, W; Parker, T; Levine, D; Rennert, H

2015-04-01

424

Emerging patterns of somatic mutations in cancer  

PubMed Central

The advance in technological tools for massively parallel, high-throughput sequencing of DNA has enabled the comprehensive characterization of somatic mutations in large number of tumor samples. Here, we review recent cancer genomic studies that have assembled emerging views of the landscapes of somatic mutations through deep sequencing analyses of the coding exomes and whole genomes in various cancer types. We discuss the comparative genomics of different cancers, including mutation rates, spectrums, and roles of environmental insults that influence these processes. We highlight the developing statistical approaches used to identify significantly mutated genes, and discuss the emerging biological and clinical insights from such analyses as well as the challenges ahead translating these genomic data into clinical impacts. PMID:24022702

Watson, Ian R.; Takahashi, Koichi; Futreal, P. Andrew; Chin, Lynda

2014-01-01

425

Does DNA repair occur during somatic hypermutation?  

PubMed Central

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

Saribasak, Huseyin; Gearhart, Patricia J.

2012-01-01

426

Induction synchrotron  

NASA Astrophysics Data System (ADS)

A novel proton synchrotron employing induction cells instead of radio frequency cavities is proposed. The major feature of the barrier bucket acceleration, where acceleration and longitudinal focusing are independently achieved is theoretically discussed with the help of multi-particle simulations. It is proved that barrier bucket acceleration allows ultimate use of longitudinal phase-space and is quite effective to substantially increase the beam intensity in synchrotrons. Engineering aspects of key devices to realize the novel synchrotron, a ferri/ferro-magnetic material loaded induction cell and a modulator being rapidly switched in synchronization with beam acceleration are described in detail. The idea is applied to an existing machine (the KEK 12 GeV-PS) and high-intensity proton rings such as JHF, ESS, and SNS and their predicted improvement in machine performance is given with numerical values for each case.

Takayama, Ken; Kishiro, Junichi

2000-08-01

427

[Interdependance between somatic symptoms, sleep and dreams].  

PubMed

Even in an established illness, somatic complains can hide other emotional inquiries. The therapist, always with a kind attitude, can ask more about patient's sexual life. This can be use of having a better idea of patient's life and problems. Talking about dreams can also be useful: it gives new and surprising elements about patient's personality and helps to progress on healing's way. PMID:24734362

Todorov, Assya

2014-03-19

428

Molecular Cytogenetic Diagnosis and Somatic Genome Variations  

PubMed Central

Human molecular cytogenetics integrates the knowledge on chromosome and genome organization at the molecular and cellular levels in health and disease. Molecular cytogenetic diagnosis is an integral part of current genomic medicine and is the standard of care in medical genetics and cytogenetics, reproductive medicine, pediatrics, neuropsychiatry and oncology. Regardless numerous advances in this field made throughout the last two decades, researchers and practitioners who apply molecular cytogenetic techniques may encounter several problems that are extremely difficult to solve. One of them is undoubtedly the occurrence of somatic genome and chromosome variations, leading to genomic and chromosomal mosaicism, which are related but not limited to technological and evaluative limitations as well as multiplicity of interpretations. More dramatically, current biomedical literature almost lacks descriptions, guidelines or solutions of these problems. The present article overviews all these problems and gathers those exclusive data acquired from studies of genome and chromosome instability that is relevant to identification and interpretations of this fairly common cause of somatic genomic variations and chromosomal mosaicism. Although the way to define pathogenic value of all the intercellular variations of the human genome is far from being completely understood, it is possible to propose recommendations on molecular cytogenetic diagnosis and management of somatic genome variations in clinical population. PMID:21358989

Vorsanova, S.G; Yurov, Y.B.; Soloviev, I.V.; Iourov, I.Y.

2010-01-01

429

Molecular cytogenetic diagnosis and somatic genome variations.  

PubMed

Human molecular cytogenetics integrates the knowledge on chromosome and genome organization at the molecular and cellular levels in health and disease. Molecular cytogenetic diagnosis is an integral part of current genomic medicine and is the standard of care in medical genetics and cytogenetics, reproductive medicine, pediatrics, neuropsychiatry and oncology. Regardless numerous advances in this field made throughout the last two decades, researchers and practitioners who apply molecular cytogenetic techniques may encounter several problems that are extremely difficult to solve. One of them is undoubtedly the occurrence of somatic genome and chromosome variations, leading to genomic and chromosomal mosaicism, which are related but not limited to technological and evaluative limitations as well as multiplicity of interpretations. More dramatically, current biomedical literature almost lacks descriptions, guidelines or solutions of these problems. The present article overviews all these problems and gathers those exclusive data acquired from studies of genome and chromosome instability that is relevant to identification and interpretations of this fairly common cause of somatic genomic variations and chromosomal mosaicism. Although the way to define pathogenic value of all the intercellular variations of the human genome is far from being completely understood, it is possible to propose recommendations on molecular cytogenetic diagnosis and management of somatic genome variations in clinical population. PMID:21358989

Vorsanova, S G; Yurov, Y B; Soloviev, I V; Iourov, I Y

2010-09-01

430

Cloning and expression of embryogenesis-regulating genes in Araucaria angustifolia (Bert.) O. Kuntze (Brazilian Pine)  

PubMed Central

Angiosperm and gymnosperm plants evolved from a common ancestor about 300 million years ago. Apart from morphological and structural differences in embryogenesis and seed origin, a set of embryogenesis-regulating genes and the molecular mechanisms involved in embryo development seem to have been conserved alike in both taxa. Few studies have covered molecular aspects of embryogenesis in the Brazilian pine, the only economically important native conifer in Brazil. Thus eight embryogenesis-regulating genes, viz., ARGONAUTE 1, CUP-SHAPED COTYLEDON 1, WUSCHEL-related WOX, S-LOCUS LECTIN PROTEIN KINASE, SCARECROW-like, VICILIN 7S, LEAFY COTYLEDON 1, and REVERSIBLE GLYCOSYLATED POLYPEPTIDE 1, were analyzed through semi-quantitative RT-PCR during embryo development and germination. All the eight were found to be differentially expressed in the various developmental stages of zygotic embryos, seeds and seedling tissues. To our knowledge, this is the first report on embryogenesis-regulating gene expression in members of the Araucariaceae family, as well as in plants with recalcitrant seeds. PMID:22481892

Schlögl, Paulo Sérgio; dos Santos, André Luis Wendt; Vieira, Leila do Nascimento; Floh, Eny Iochevet Segal; Guerra, Miguel Pedro

2012-01-01

431

Cloning and expression of embryogenesis-regulating genes in Araucaria angustifolia (Bert.) O. Kuntze (Brazilian Pine).  

PubMed

Angiosperm and gymnosperm plants evolved from a common ancestor about 300 million years ago. Apart from morphological and structural differences in embryogenesis and seed origin, a set of embryogenesis-regulating genes and the molecular mechanisms involved in embryo development seem to have been conserved alike in both taxa. Few studies have covered molecular aspects of embryogenesis in the Brazilian pine, the only economically important native conifer in Brazil. Thus eight embryogenesis-regulating genes, viz., ARGONAUTE 1, CUP-SHAPED COTYLEDON 1, WUSCHEL-related WOX, S-LOCUS LECTIN PROTEIN KINASE, SCARECROW-like, VICILIN 7S, LEAFY COTYLEDON 1, and REVERSIBLE GLYCOSYLATED POLYPEPTIDE 1, were analyzed through semi-quantitative RT-PCR during embryo development and germination. All the eight were found to be differentially expressed in the various developmental stages of zygotic embryos, seeds and seedling tissues. To our knowledge, this is the first report on embryogenesis-regulating gene expression in members of the Araucariaceae family, as well as in plants with recalcitrant seeds. PMID:22481892

Schlögl, Paulo Sérgio; Dos Santos, André Luis Wendt; Vieira, Leila do Nascimento; Floh, Eny Iochevet Segal; Guerra, Miguel Pedro

2012-01-01

432

Somatization, somatosensory amplification, attribution styles and illness behaviour: a review.  

PubMed

Somatic symptoms have been conceptualized in many different ways in literature. Current classifications mainly focus on the numbers of symptoms, with relative neglect of the underlying psychopathology. Researchers have emphasized the importance of a number of experiential, perceptual and cognitive-behavioural aspects of somatization. This review focuses on existing literature on the role of somatosensory amplification, attribution styles, and illness behaviour in somatization. Evidence suggests that somatosensory amplification is neither sensitive nor specific to somatizing states, and that other factors like anxiety, depression, neuroticism, alexithymia may also have an influence. Attribution research supports the existence of multiple causal attributions, which are related to the numbers of somatic symptoms. While somatizing patients have more organic attributions, depressed patients have more psychological attributions. A global somatic attribution style is associated with the number of obscure somatic symptoms, while a psychological attribution style is associated with both--psychological and somatic-- symptoms of depression and anxiety. There are conflicting findings with respect to the role of normalizing attributions in reducing physician recognition of anxiety and depression. Specific symptom attributions appear to explain physician recognition of psychological distress, but global attribution styles do not appear to explain any further variance in physician recognition beyond that explained by specific causal attributions. Illness behaviour has been studied in two distinct ways in literature. Research focusing on attendance rates as a form of illness behaviour suggests that somatization is associated with high levels of health care utilization. There is also some evidence that health care utilization, amplification and attributions styles may be interrelated among somatizing patients. More structured ways to assess illness behaviour have found high levels of abnormal illness behaviour in this population. Overall, research appears to suggest a complex (and as yet unclear) relationship between somatic symptoms and underlying cognitions/illness behaviours. While it is clear that somatization is closely related to a number of perceptual and cognitive-behavioural factors, the precise nature of these relationships are yet to be elucidated. PMID:16451877

Duddu, Venugopal; Isaac, Mohan K; Chaturvedi, Santosh K

2006-02-01

433

Indispensable Roles of Plastids in Arabidopsis thaliana Embryogenesis  

PubMed Central

The plastid is an organelle vital to all photosynthetic and some non-photosynthetic eukaryotes. In the model plant Arabidopsis thaliana, a number of nuclear genes encoding plastid proteins have been found to be necessary for embryo development. However, the exact roles of plastids in this process remain largely unknown. Here we use publicly available datasets to obtain insights into the relevance of plastid activities to A. thaliana embryogenesis. By searching the SeedGenes database (http://www.seedgenes.org) and recent literature, we found that, of the 339 non-redundant genes required for proper embryo formation, 108 genes likely encode plastid-targeted proteins. Nineteen of these genes are necessary for development of preglobular embryos and/or their conversion to globular embryos, of which 13 genes encode proteins involved in non-photosynthetic metabolism. By contrast, among 38 genes which are dispensable for globular embryo formation but necessary for further development, only one codes for a protein involved in metabolism. Products of 21 of the 38 genes play roles in plastid gene expression and maintenance. Examination of RNA profiles of embryos at distinct growth stages obtained in laser-capture microdissection coupled with DNA microarray experiments revealed that most of the identified genes are expressed throughout embryo morphogenesis and maturation. These findings suggest that metabolic activities are required at preglobular and throughout all stages of embryo development, whereas plastid gene expression becomes necessary during and/or after the globular stage to sustain various activities of the organelle including photosynthetic electron transport. PMID:21286311

Hsu, Shih-Chi; Belmonte, Mark F; Harada, John J; Inoue, Kentaro

2010-01-01

434

Contrasting Storage Protein Synthesis and Messenger RNA Accumulation during Development of Zygotic and Somatic Embryos of Alfalfa (Medicago sativa L.) 1  

PubMed Central

During development on hormone-free media, somatic embryos pass through distinct morphological stages that superficially resemble those of zygotic embryo development (globular, heart, torpedo, cotyledonary stages). Despite these similarities, they differ from zygotic embryos in the extent of cotyledonary development and the patterns of synthesis and quantitative expression of seed-specific storage proteins (7S, 11S, and 2S proteins). Alfin (7S) is the first storage protein synthesized in developing zygotic embryos (stage IV). The 11S (medicagin) and 2S (Low Molecular Weight, LMW) storage proteins are not detectable until the following stage of development (stage V), although all three are present before the completion of embryo enlargement. Likewise, the 7S storage protein is the first to be synthesized in developing somatic embryos (day 5). Medicagin is evident by day 7 and the LMW protein by day 10. In contrast to zygotic embryos, alfin remains the predominant storage protein in somatic embryos throughout development. Not only are the relative amounts of medicagin and the LMW protein reduced in somatic embryos but the LMW protein is accumulated much later than the other proteins. Quantification of the storage protein mRNAs (7S, 11S, and 2S) by northern blot analysis confirms that there are substantial differences in the patterns of message accumulation in zygotic and somatic embryos of alfalfa (Medicago sativa). In zygotic embryos, the 7S, 11S, and 2S storage protein mRNAs are abundant during maturation and, in particular, during the stages of maximum protein synthesis (alfin, stages VI and VII; medicagin, stage VII; LMW, stage VII). In somatic embryos, the predominance of the 7S storage protein is correlated with increased accumulation of its mRNA, whereas the limited synthesis of the 11S storage protein is associated with much lower steady-state levels of its message. The mRNA for the LMW protein is present already by 3 days after transfer to hormone-free media, yet that protein is not evident on stained gels until day 10. Thus, both transcriptional and posttranscriptional events appear to be important in determining the protein complement of these seed tissues. On the basis of storage protein and mRNA accumulation, mature (14 days) somatic embryos most closely resemble stage VI zygotic embryos. The results of the developmental comparison also suggest that the patterns of synthesis of the individual storage proteins (7S, 11S, or 2S) are regulated independently of each other during embryogenesis in alfalfa. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:16668882

Krochko, Joan E.; Pramanik, Saroj K.; Bewley, J. Derek

1992-01-01

435

Prevalence of somatic alterations in the colorectal cancer cell genome  

PubMed Central

Although a small fraction of human cancers have increased rates of somatic mutation because of known deficiencies in DNA repair, little is known about the prevalence of somatic alterations in the vast majority of human cancers. To systematically assess nonsynonymous somatic alterations in colorectal neoplasia, we used DNA sequencing to analyze ?3.2 Mb of coding tumor DNA comprising 1,811 exons from 470 genes. In total, we identified only three distinct somatic mutations, comprising two missense changes and one 14-bp deletion, each in a different gene. The accumulation of approximately one nonsynonymous somatic change per Mb of tumor DNA is consistent with a rate of mutation in tumor cells that is similar to that of normal cells. These data suggest that most sporadic colorectal cancers do not display a mutator phenotype at the nucleotide level. They also have significant implications for the interpretation of somatic mutations in candidate tumor-suppressor genes. PMID:11867767

Wang, Tian-Li; Rago, Carlo; Silliman, Natalie; Ptak, Janine; Markowitz, Sanford; Willson, James K. V.; Parmigiani, Giovanni; Kinzler, Kenneth W.; Vogelstein, Bert; Velculescu, Victor E.

2002-01-01

436

Predictive factors for somatization in a trauma sample  

PubMed Central

Background Unexplained somatic symptoms are common among trauma survivors. The relationship between trauma and somatization appears to be mediated by posttraumatic stress disorder (PTSD). However, only few studies have focused on what other psychological risk factors may predispose a trauma victim towards developing somatoform symptoms. Methods The present paper examines the predictive value of PTSD severity, dissociation, negative affectivity, depression, anxiety, and feeling incompetent on somatization in a Danish sample of 169 adult men and women who were affected by a series of explosions in a firework factory settled in a residential area. Results Negative affectivity and feelings of incompetence significantly predicted somatization, explaining 42% of the variance. PTSD was significant until negative affectivity was controlled for. Conclusion Negative affectivity and feelings of incompetence significantly predicted somatization in the trauma sample whereas dissociation, depression, and anxiety were not associated with degree of somatization. PTSD as a risk factor was mediated by negative affectivity. PMID:19126224

2009-01-01

437

Embryogenesis of the mayfly Ephemera japonica McLachlan (Insecta: Ephemeroptera, Ephemeridae), with special reference to abdominal formation  

Microsoft Academic Search

Embryogenesis of the mayfly Ephemera japonica is described, with special reference to the abdominal morphogenesis. Cleavage is of the typical superficial type. The germ disc is formed by the cell concentration of the embryonic area broadly defined at the posterior half of the blastoderm. The embryo undergoes embryogenesis of the typical short germ type. Blastoki- nesis in which the extensive

Koji Tojo; Ryuichiro Machida

1997-01-01

438

Effects of encapsulation on Citrus reticulata Blanco somatic embryo conversion  

Microsoft Academic Search

Preliminary experiments on calcium-sodium alginate encapsulation of somatic embryos from anther culture were performed, in\\u000a order to evaluate the effect of this technique on the recovery of plantlets, and the applicability of the synthetic seed technology\\u000a to Citrus reticulata Blanco. Frequencies of conversion of somatic embryos on plant growth medium were 15.0%, 26.7% and 50.0%,\\u000a respectively, when the somatic embryos

Germanŕ M. Antonietta; Piccioni Emanuele; Standardi Alvaro

1998-01-01

439

Human somatic mutation assays as biomarkers of carcinogenesis  

SciTech Connect

This paper describes four assays that detect somatic gene mutations in humans: the hypoxanthine-guanine phosphoribosyl transferase assay, the glycophorin A assay, the HLA-A assay, and the sickle cell hemoglobin assay. Somatic gene mutations can be considered a biomarker of carcinogenesis, and assays for somatic mutation may assist epidemiologists in studies that attempt to identify factors associated with increased risks of cancer. Practical aspects of the use of these assays are discussed.

Compton, P.J.E.; Smith, M.T. (Univ. of California, Berkeley (United States)); Hooper, K. (California Dept. of Health Services, Berkeley (United States))

1991-08-01

440

Advances in Reprogramming Somatic Cells to Induced Pluripotent Stem Cells  

Microsoft Academic Search

Traditionally, nuclear reprogramming of cells has been performed by transferring somatic cell nuclei into oocytes, by combining\\u000a somatic and pluripotent cells together through cell fusion and through genetic integration of factors through somatic cell\\u000a chromatin. All of these techniques changes gene expression which further leads to a change in cell fate. Here we discuss recent\\u000a advances in generating induced pluripotent

Minal Patel; Shuying Yang

2010-01-01

441

Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells  

Microsoft Academic Search

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

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

2007-01-01

442

Class IIa Histone Deacetylases and Myocyte Enhancer Factor 2 Proteins Regulate the Mesenchymal-to-Epithelial Transition of Somatic Cell Reprogramming*  

PubMed Central

Class IIa histone deacetylases (HDACs) and myocyte enhancer factor 2 (MEF2) proteins compose a signaling module that orchestrates lineage specification during embryogenesis. We show here that this module also regulates the generation of mouse induced pluripotent stem cells by defined transcription factors. Class IIa HDACs and MEF2 proteins rise steadily during fibroblast reprogramming to induced pluripotent stem cells. MEF2 proteins tend to block the process by inducing the expression of Tgf? cytokines, which impairs the necessary phase of mesenchymal-to-epithelial transition (MET). Conversely, class IIa HDACs endeavor to suppress the activity of MEF2 proteins, thus enhancing the MET and colony formation efficiency. Our work highlights an unexpected role for a developmental axis in somatic cell reprogramming and provides new insight into how the MET is regulated in this context. PMID:23467414

Zhuang, Qiang; Qing, Xiaobing; Ying, Yue; Wu, Haitao; Benda, Christina; Lin, Jiao; Huang, Zhijian; Liu, Longqi; Xu, Yan; Bao, Xichen; Qin, Baoming; Pei, Duanqing; Esteban, Miguel A.

2013-01-01

443

The ?-cyclin expression at early stages of embryogenesis of Brassica rapa L. under clinorotation  

NASA Astrophysics Data System (ADS)

We present some results of comparison studying of Brassica embryo development and the ?-cyclin genes expression under slow horizontal clinorotation and in the laboratory control. Some backlog of the ?1-cyclin genes expression at early stages of embryogenesis under clinorotation was revealed in comparison with the laboratory control. The similar level of the ?3-cyclin expression at all stages of embryo formation (from one to nine days) in both variants is shown. Some delays in the rate of Brassica rapa embryo development under clinorotation in comparison with the laboratory control can be a result of decrease of a level and some backlog of the ?1-cyclin expression at early stages of embryogenesis.

Artemenko, O. A.; Popova, A. F.

444

Confidence-based Somatic Mutation Evaluation and Prioritization  

PubMed Central

Next generation sequencing (NGS) has enabled high throughput discovery of somatic mutations. Detection depends on experimental design, lab platforms, parameters and analysis algorithms. However, NGS-based somatic mutation detection is prone to erroneous calls, with reported validation rates near 54% and congruence between algorithms less than 50%. Here, we developed an algorithm to assign a single statistic, a false discovery rate (FDR), to each somatic mutation identified by NGS. This FDR confidence value accurately discriminates true mutations from erroneous calls. Using sequencing data generated from triplicate exome profiling of C57BL/6 mice and B16-F10 melanoma cells, we used the existing algorithms GATK, SAMtools and SomaticSNiPer to identify somatic mutations. For each identified mutation, our algorithm assigned an FDR. We selected 139 mutations for validation, including 50 somatic mutations assigned a low FDR (high confidence) and 44 mutations assigned a high FDR (low confidence). All of the high confidence somatic mutations validated (50 of 50), none of the 44 low confidence somatic mutations validated, and 15 of 45 mutations with an intermediate FDR validated. Furthermore, the assignment of a single FDR to individual mutations enables statistical comparisons of lab and computation methodologies, including ROC curves and AUC metrics. Using the HiSeq 2000, single end 50 nt reads from replicates generate the highest confidence somatic mutation call set. PMID:23028300

de Graaf, Jos; Wagner, Meike; Paret, Claudia; Kneip, Christoph; Türeci, Özlem; Diken, Mustafa; Britten, Cedrik; Kreiter, Sebastian; Koslowski, Michael; Castle, John C.; Sahin, Ugur

2012-01-01

445

Release of somatic embryogenic potential from excised zygotic embryos of carrot and maintenance of proembryonic cultures in hormone-free medium  

NASA Technical Reports Server (NTRS)

Excised zygotic embryos, mericarps ("seeds") and hypocotyls of seedlings of cultivated carrot Daucus carota cv. Scarlet Nantes were evaluated for their ability to generate somatic embryos on a semisolid hormone-free nutrient medium. Neither intact zygotic embryos nor hypocotyls ever produced somatic embryos. However, mericarps and broken zygotic embryos were excellent sources for somatic embryo production (response levels as high as 86%). Somatic embryo formation was highest from cotyledons, but was also observed on isolated hypocotyls and root tips of mature zygotic embryos. On media containing unreduced nitrogen, somatic embryo formation led to the generation of vigorous cultures comprised entirely of somatic embryos at various stages of development which in turn proliferated still other somatic embryos. However, a medium was devised which when 1-5 mM NH4+ was the sole nitrogen source, led only to a proliferation of globular proembryos. Sustained subculturing of these proembryos at 2-3 week intervals enabled establishment of highly uniform cultures in which no further development into more mature stages of embryonic development occurred. These have been maintained, without decline, as morphogenetically competent proembryonic globules for over ten months. A basal medium containing from 1-5 mM NH4+ as the sole nitrogen source appears not to be inductive to somatic proembryo formation. Instead, such a medium is best thought of as permissive to the expression of embryogenically determined cells within zygotic embryos. By excising and breaking or wounding zygotic embryos, constituent cells are probably released from positional or chemical restraints and thus are able to express their innate embryogenic potential. Once a proembryonic culture is established, this medium containing 1-5 mM NH4+ as the sole nitrogen source provides a nonpermissive environment to the development and growth of later embryonic stages, but it does allow the continued formation and multiplication of globular somatic proembryos. The sequence of events leading from excised broken zygotic embryos to the formation of somatic embryos and the maintenance of somatic proembryos are demonstrated by scanning electron microscopy and histological preparations. Germination levels from intact zygotic embryos on media with varying levels and ratios of unreduced vs. reduced inorganic nitrogen were determined as well and provided baseline or control data on the type of response obtained from nonwounded material.

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

1989-01-01

446

Ancient origin of somatic and visceral neurons  

PubMed Central

Background A key to understanding the evolution of the nervous system on a large phylogenetic scale is the identification of homologous neuronal types. Here, we focus this search on the sensory and motor neurons of bilaterians, exploiting their well-defined molecular signatures in vertebrates. Sensorimotor circuits in vertebrates are of two types: somatic (that sense the environment and respond by shaping bodily motions) and visceral (that sense the interior milieu and respond by regulating vital functions). These circuits differ by a small set of largely dedicated transcriptional determinants: Brn3 is expressed in many somatic sensory neurons, first and second order (among which mechanoreceptors are uniquely marked by the Brn3+/Islet1+/Drgx+ signature), somatic motoneurons uniquely co-express Lhx3/4 and Mnx1, while the vast majority of neurons, sensory and motor, involved in respiration, blood circulation or digestion are molecularly defined by their expression and dependence on the pan-visceral determinant Phox2b. Results We explore the status of the sensorimotor transcriptional code of vertebrates in mollusks, a lophotrochozoa clade that provides a rich repertoire of physiologically identified neurons. In the gastropods Lymnaea stagnalis and Aplysia californica, we show that homologues of Brn3, Drgx, Islet1, Mnx1, Lhx3/4 and Phox2b differentially mark neurons with mechanoreceptive, locomotory and cardiorespiratory functions. Moreover, in the cephalopod Sepia officinalis, we show that Phox2 marks the stellate ganglion (in line with the respiratory — that is, visceral— ancestral role of the mantle, its target organ), while the anterior pedal ganglion, which controls the prehensile and locomotory arms, expresses Mnx. Conclusions Despite considerable divergence in overall neural architecture, a molecular underpinning for the functional allocation of neurons to interactions with the environment or to homeostasis was inherited from the urbilaterian ancestor by contemporary protostomes and deuterostomes. PMID:23631531

2013-01-01

447

Improved techniques for the induction of mammalian cell hybridization by polyethylene glycol  

Microsoft Academic Search

Modifications in the techniques for the induction of mammalian somatic cell hybridization by polyethylene glycol (PEG) have led to procedures that are rapid, simple, and effective. The basic improvements, for both monolayer and suspension fusions, are a short exposure to PEG and a rapid dilution of PEG following treatment. There is a marked effect of PEG concentration on cell hybridization,

Richard L. Davidson; Park S. Gerald

1976-01-01

448

Somatic stem cell niche tropism in Wolbachia.  

PubMed

Wolbachia are intracellular bacteria found in the reproductive tissue of all major groups of arthropods. They are transmitted vertically from the female hosts to their offspring, in a pattern analogous to mitochondria inheritance. But Wolbachia phylogeny does not parallel that of the host, indicating that horizontal infectious transmission must also occur. Insect parasitoids are considered the most likely vectors, but the mechanism for horizontal transfer is largely unknown. Here we show that newly introduced Wolbachia cross several tissues and infect the germline of the adult Drosophila melanogaster female. Through investigation of bacterial migration patterns during the course of infection, we found that Wolbachia reach the germline through the somatic stem cell niche in the D. melanogaster germarium. In addition, our data suggest that Wolbachia are highly abundant in the somatic stem cell niche of long-term infected hosts, implying that this location may also contribute to efficient vertical transmission. This is, to our knowledge, the first report of an intracellular parasite displaying tropism for a stem cell niche. PMID:16724067

Frydman, Horacio M; Li, Jennifer M; Robson, Drew N; Wieschaus, Eric

2006-05-25

449

Genes encoding novel secreted and transmembrane proteins are temporally and spatially regulated during Drosophila melanogaster embryogenesis  

Microsoft Academic Search

BACKGROUND: Morphogenetic events that shape the Drosophila melanogaster embryo are tightly controlled by a genetic program in which specific sets of genes are up-regulated. We used a suppressive subtractive hybridization procedure to identify a group of developmentally regulated genes during early stages of D. melanogaster embryogenesis. We studied the spatiotemporal activity of these genes in five different intervals covering 12

Alejandro Zúńiga; Christian Hödar; Patricia Hanna; Freddy Ibáńez; Pablo Moreno; Rodrigo Pulgar; Luis Pastenes; Mauricio González; Verónica Cambiazo

2009-01-01

450

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

451

The Pesticide Malathion Disrupts "Xenopus" and Zebrafish Embryogenesis: An Investigative Laboratory Exercise in Developmental Toxicology  

ERIC Educational Resources Information Center

Malathion is an organophosphorus insecticide, which is often sprayed to control mosquitoes. When applied to aquatic habitats, malathion can also influence the embryogenesis of non-target organisms such as frogs and fish. We modified the frog embryo teratogen assay in "Xenopus" (FETAX), a standard toxicological assay, into an investigative…

Chemotti, Diana C.; Davis, Sarah N.; Cook, Leslie W.; Willoughby, Ian R.; Paradise, Christopher J.; Lom, Barbara

2006-01-01

452

FlyExpress: Visual mining of spatiotemporal patterns for genes and publications in Drosophila embryogenesis  

E-print Network

melanogaster is a canonical model organism for understanding animal development. More than one hundred thousand Drosophila melanogaster embryogenesis. By clicking on specific locations in pictures of fly embryos from1 FlyExpress: Visual mining of spatiotemporal patterns for genes and publications in Drosophila

Ye, Jieping

453

Abstract This study examines early embryo-genesis in two species of darters, Etheostoma  

E-print Network

of conspecific versus heterospecific crosses revealed an asymmetric postmating reproductive barrier. E. caeruleum was compromised at all stages, but appeared to be concentrated around epiboly, or cell migration. As epiboly of early embryogenesis in Rainbow and Banded Darters (Percidae: Etheostoma) reveals asymmetric postmating

Behe, Michael J.

454

Asymmetric expression of Syndecan-2 in early chick embryogenesis Takahiro Fukumoto, Michael Levin*  

E-print Network

Asymmetric expression of Syndecan-2 in early chick embryogenesis Takahiro Fukumoto, Michael Levin streak between st. 1 and 3 in the chick embryo, and is restricted to the rostral and caudal tips transcript in the chick embryo and indicate that in contrast to protein-level asymmetries, which underlie

Levin, Michael

455

In Vitro Fertilization with Isolated, Single Gametes Results in Zygotic Embryogenesis and Fertile Maize Plants  

Microsoft Academic Search

We demonstrate here the possibility of regenerating phenotypically normal, fertile maize plants via in vitro fertilization of isolated, single sperm and egg cells mediated by electrofusion. The technique leads to the highly efficient formation of polar zygotes, globular structures, proembryos, and transition-phase embryos and to the formation of plants from individually cultured fusion products. Regeneration of plants occurs via embryogenesis

Erhard Kranz; Horst Lor

1993-01-01

456

Germinal and somatic cell interrelationships in gonadal sex differentiation  

E-print Network

Germinal and somatic cell interrelationships in gonadal sex differentiation Wai-Sum O T. G. BAKER affecting the differentiation and development of germ cells in gonadal differentiation is discussed. It has an « artificial » chimaeric gonad which contains somatic and germinal cells of opposite sexes. The results

Paris-Sud XI, Université de

457

INTRODUCTION A hierarchy of regulatory genes controls somatic sex  

E-print Network

INTRODUCTION A hierarchy of regulatory genes controls somatic sex determination and differentiation differentiation in the CNS (Taylor and Truman, 1992; Villella and Hall, 1996). The sex determination function differentiation genes that are sex-specifically regulated by the somatic sex determination hierarchy are the yolk

Baker, Bruce S.

458

BREEDING, SELECTION AND SOMATIC CELL COUNTS: WHERE ARE WE TODAY?  

Microsoft Academic Search

Genetics can help prevent mastitis and reduce somatic cell count. The purpose of this article is to inform producers, veterinarians, extension personnel, artificial breeding personnel, and genetics specialists about the methods and usefulness of genetics to improve milk quality. The USDA Animal Improvement Programs Laboratory (AIPL) has published genetic evaluations for Somatic Cell Score (SCS) since 1994 (Schutz et al.,

George Shook

459

Development of the Ghent Multidimensional Somatic Complaints Scale  

ERIC Educational Resources Information Center

The present study aimed at developing a new scale that operationalizes a hierarchical model of somatic complaints. First, 63 items representing a wide range of symptoms and sensations were compiled from somatic complaints scales and emotion literature. These complaints were rated by Belgian students (n = 307) and Belgian adults (n = 603).…

Beirens, Koen; Fontaine, Johnny R. J.

2010-01-01

460

Somatics in the Dance Studio: Embodying Feminist/Democratic Pedagogy  

ERIC Educational Resources Information Center

Since the 1970s, somatics have increasingly become a part of the dance training landscape. Although the psychophysical benefits seem sufficient in themselves to warrant inclusion in dance, this article explores another possible outcome of embracing somatic pedagogical principles, a change that affects not "what" is taught in a dance class, but…

Burnidge, Anne

2012-01-01